·
A foundational principle of the medical
tradition is to do no harm: primum non nocere. In 2000, a widely publicized report from
the Institute of Medicine, To Err is Human, estimated that 98,000 people die
each year in U.S. hospitals as a result of medical injuries. This report, among
others already in the literature, led to the creation of a number of national
quality improvement projects that were specifically designed to improve
surgical care in hospitals. One of the best known is the Surgical Care Improvement Project (SCIP), part
of a national campaign aimed at reducing surgical complications by 25% by 2010.
·
A recently identified protein, pendrin, is
thought to mediate iodine efflux at the apical membrane
of thyrocyte.
·
An emerging and still controversial indication
for circumcision is in the prevention
of sexually acquired human immunodeficiency virus (HIV) infection in communities
where this disease is common; large clinical trials have recently shown that
circumcision reduces the risk of HIV transmission.
·
Recent myocardial
infarction is a strong contraindication to elective anaesthesia.
There is a significant mortality rate from anaesthesia
within 3 months of infarction and elective procedures should ideally be delayed
until at least 6 months have elapsed.
·
Recently, the British
Association of Parenteral and Enteral
Nutrition introduced a Malnutrition Universal
Screening Tool (MUST), which is a fivestep
screening tool to identify adults who are malnourished or at risk of undernutrition. Takes into account
BMI, Wt LOSS IN 3-6 months and ACUTE DISEASE EFFECT.
·
Recent reports of tumour
implantation in the locations of port sites have raised important
questions about the future of the laparoscopic treatment of malignancy.
·
Recently, an interspinous
process decompression system (X-stop)
has been found to be effective for patients suffering from lumbar spinal stenosis when compared with non-operative therapy.
·
Femoroacetabular impingement (FAI)
has been proposed as an aetiological factor
responsible for the development of primary osteoarthritis. The
theory is based on the observation that, in certain hips with aberrant
morphological features, an abnormal contact occurs between the proximal femur
and the acetabular rim during the terminal range of
movement, leading to lesions of the acetabular labrum
and/or the adjacent acetabular cartilage. This type
of repetitive abutment in due course leads to progressive loss of the articular cartilage and labral
lesions because of a sheering stress, resulting in degenerative joint disease
if the underlying cause is not addressed.
·
E-thrombosis has
been used to describe blood clots occurring in people sitting at their
computers for long periods of time.
·
A recent technique known as transanal
endoscopic microsurgery (TEM) has been developed (Buess), which has improved the endoanal
approach for the local removal of villous
adenomas. The method requires the insertion of a large operating
sigmoidoscope. The rectum is distended by carbon
dioxide insufflation, the operative field is
magnified by a camera inserted via the sigmoidoscope,
and the image is displayed on a monitor. The lesion is excised using specially
designed instruments. The technique is highly specialised
and takes a considerable amount of time to master.
·
Non-heart-beating
(asystolic) donors
There is an increasing use of kidneys and more recently
livers from non-heart-beating (asystolic) donors
(NHBD) in an attempt to address the shortage of organs for transplantation.
Kidneys may be procured from patients who are dead on arrival at the hospital
or who have died after withdrawal of support or following unsuccessful
resuscitation. NHBD can be grouped according to the Maastricht classification
as follows:
• category 1: dead on arrival at
hospital;
• category 2: unsuccessful
resuscitation in hospital;
• category 3: ‘awaiting cardiac
arrest’ after withdrawal of support;
• category 4: cardiac arrest while
brain dead.
Maastricht category 1 and 2 donors are sometimes referred to
as uncontrolled NHBD.
·
Intradiscal electrothermal therapy (IDET) was heralded as a new treatment for patients with discographically proven discogenic
low back pain. There are two randomized controlled trials assessing the
efficacy of IDET. The first showed modest overall benefit,
and the second showed IDET to be no more effective than placebo for the
treatment of chronic discogenic low back pain.
·
One study has suggested an association between
Candida sepsis and ROP in extremely-low-birth-weight infants. The study found
increased severity of ROP and need for laser therapy after candidal
infection.
·
The recently introduced Harmonic Scalpel is an
instrument that cuts and coagulates tissue via vibration at 55 kHz. The device
converts electrical energy into mechanical motion. The motion of the blade
causes collagen molecules within the tissue to become denatured forming a
coagulum. There is no significant electrical current that flows through the
patient. The instrument has proved advantageous in performing thyroidectomy, hemorrhoidectomy, transsection of the short gastric veins during splenectomy, and in transecting hepatic parenchyma.
·
Drotracogin alpha
(activated), also known as Xigris, is a recombinant
form of human-activated protein C. The use of this agent in a series of
patients with sepsis syndrome has been associated with a 6% overall reduction
in mortality
·
The AIS
is a list which assigns a number from 1 (minor injury) to 6 (always fatal) for
the various spectrum of organ injuries. The Injury Severity Score (ISS) was devised to address this concern. The
ISS is calculated by squaring the AIS from the three worst injured of six body
compartments (head and neck, face, chest, abdomen and pelvis, extremities, and
external) and adding them together. Scores can range from 0 to 75. The Revised Trauma Score (RTS) is most commonly
used today. It is calculated from the GCS, blood
pressure, and respiratory rate, with the GCS being most heavily
weighted. The RTS is a purely physiologic score which is compromised by the
relative insensitivity of these common clinical measurements. More recently,
the TRISS method (Trauma and Injury
Severity Score) was developed to incorporate both the RTS
and ISS, thereby combining physiologic and anatomic scores, as well as
enhancing the importance of head injury. Unfortunately, TRISS remains
fundamentally flawed because of the limitations of RTS and ISS. Newer versions
of the TRISS concept, such as ASCOT
(A Severity Characterization of Trauma), have also failed to improve the
prediction of postinjury mortality.
·
Recently, serum procalcitonin
has been shown to be a sensitive marker of significant infection in burn
patients.
·
main effect of arginine on wound healing is to enhance wound collagen
deposition. Recently, a dietary supplemental regimen of arginine,
β-hydroxy-β-methyl butyrate, and glutamine was found to significantly and
specifically enhance collagen deposition in elderly, healthy human volunteers
when compared to an isocaloric, isonitrogenous
supplement
·
High-throughput technologies such as matrix-assisted laser-desorption-ionization time of
flight (MALDI-TOF) mass spectroscopy and liquid
chromatography-ion-spray tandem mass spectroscopy (LC-MS/MS) have
revolutionized the field of proteomics and are now being used to compare serum
protein profiles between patients with cancer and individuals without cancer.Recently, investigators have compared the proteomic
profiles of patients with prostate cancer and ovarian cancer to those of
controls, identifying unique proteins in the sera of cancer patients.Identification
of unique proteins as well as unique proteomic profiles for most cancer types
is being pursued actively by many researchers, which if successful, could
dramatically enhance our ability to detect cancers early.
·
The most commonly used device for VSD Closure is
the Amplatzer septal occluder (AGA Medical Corp, MN) device, which is a Nitinol metal mesh device, placed percutaneously
and delivered with echo and fluoroscopic guidance.
·
Aortic Valve Repair Technique: Ross, David, Yacoub, and Casselman
·
An association between PAD and hypertriglyceridemia has been reported, but the strength of
this association is unclear. Recently, it has been shown that Lp(a) is
a significant independent risk factor for PAD.
·
Clagett has
popularized the use of bilateral superficial femoral vein to replace infected
aortic grafts. This technique can also be useful for treatment of mycotic aneurysms.
·
The benefit of carotid endarterectomy
for patients with symptomatic cerebrovascular disease
has recently been established by both the ECST and NASCET trials.
·
An intraluminal
electrical impedance catheter has recently been developed for the
measurement of gastrointestinal function. Impedance is the ratio of voltage to
current, and is a measure of the electrical conductivity of a hollow organ and
its contents. Intraluminal electrical impedance is
inversely proportional to the electrical conductivity of the luminal contents
and the cross-sectional area of the lumen. Air has a very low electrical
conductivity and therefore high impedance. Saliva and food cause an impedance
decrease because of their increased conductivity. Luminal dilatation results in
a decrease in impedance, whereas luminal contraction yields an impedance
increase. Investigators to date have established the impedance waveform
characteristics that define esophageal bolus transport. This allows for the
characterization of both esophageal function, via quantification of bolus
transport, and gastroesophageal reflux.
·
Recently it has been noted that the anorexic
hormone leptin, secreted mostly by fat but also by
gastric mucosa, inhibits gastric emptying, perhaps through the same pathway as
CCK (which also has properties of a satiety hormone). The orexic
hormone ghrelin has opposite effect.
·
GLP-2 both stimulates cellular proliferation and
inhibits apoptosis in the intestinal epithelium. It has been demonstrated to
induce intestinal regeneration and promote healing in numerous experimental
models of intestinal disease. It is currently under clinical evaluation as an intestinotrophic agent in patients suffering from the short
bowel syndrome, as discussed later under "Short-Bowel Syndrome."
·
serial transverse enteroplasty procedure (STEP) was described for SBS. This
procedure is designed to accomplish lengthening of dilated small intestine
without the need for separating its dual vasculature
·
PET using H2(15)O has
recently been shown to be a noninvasive method to measure portal venous and
hepatic arterial blood flow.
·
Pancreastatin is a
recently discovered pancreatic islet peptide product that inhibits insulin, and
possibly somatostatin release, and augments glucagon release.In addition to this effect on the endocrine
pancreas, pancreastatin inhibits pancreatic exocrine
secretion.
·
mutations in cationic trypsinogen gene PRSS1,
which results in pancreatitis.
·
The measurement of IL-6
has recently been shown to distinguish patients with mild or severe forms of
the Acute Pancreatitis. Another prognostic marker under evaluation is urinary-trypsinogen activation
peptide (TAP). TAP is a five- to seven-amino acid peptide that is
released from the N-terminus of trypsinogen during
its activation.
·
The recently identified protein pendrin is thought to mediate iodine efflux at the apical
membrane of Thyroid Follicle.
·
Recently, salivary cortisol
measurements using commercially available kits also have demonstrated superior
sensitivity in diagnosing Cushing's syndrome. However, they are not used routinely.
·
Current resuscitation algorithms are based on
the sequence of crystalloid followed by red blood cells and then plasma and
platelet transfusions and have been in widespread use
since the 1970s. Recently, the damage control resuscitation (DCR) strategy,
aimed at halting and/or preventing rather than treating the lethal triad of coagulopathy, acidosis, and hypothermia, has challenged
traditional thinking on early resuscitation strategies.
·
Following direct tissue injury or infection,
there are several mechanisms that lead to the activation of the active
inflammatory and immune responses. These include release of bioactive peptides
by neurons in response to pain and the release of intracellular molecules by
broken cells, such as heat shock proteins, mitochondrial peptides, heparan sulfate, high mobility group box 1, and RNA. Only
recently has it been realized that the release of intracellular products from
damaged and injured cells can have paracrine and
endocrine-like effects on distant tissues to activate the inflammatory and
immune responses. This hypothesis, which was first proposed by Matzinger, is known as danger signaling. Under this
novel paradigm of immune function, endogenous molecules are capable of
signaling the presence of danger to surrounding cells and tissues. These
molecules that are released from cells are known as damage
associated molecular patterns (DAMPs).
DAMPs are recognized by cell surface receptors to effect intracellular
signaling that primes and amplifies the immune response. These receptors are
known as pattern recognition receptors (PRRs)
and include the Toll-like receptors (TLRs) and the receptor for advanced glycation end products. Interestingly, TLRs and PRRs were first recognized for their role in
signaling as part of the immune response to the entry of microbes and their
secreted products into a normally sterile environment. These bacterial
products, including lipopolysaccharide, are known as pathogen-associated molecular patterns. The salutary consequences of PRR activation most
likely relate to the initiation of the repair process and the mobilization of
antimicrobial defenses at the site of tissue disruption. However, in the
setting of excessive tissue damage, the inflammation itself may lead to further
tissue damage amplifying the response both at the local and systemic level. PRR
activation leads to intracellular signaling and release of cellular products
including cytokines.
·
The use of corticosteroids
in the treatment of sepsis and septic shock has been controversial
for decades. The observation that severe sepsis often is associated with
adrenal insufficiency or glucocorticoid receptor
resistance has generated renewed interest in therapy for septic shock with
corticosteroids. A single IV dose of 50 mg of hydrocortisone improved mean
arterial blood pressure response relationships to norepinephrine
and phenylephrine in patients with septic shock, and
was most notable in patients with relative adrenal insufficiency. A more recent
study evaluated therapy with hydrocortisone (50 mg IV every 6 hours) and fludrocortisone (50 g orally
once daily) vs. placebo for 1 week in patients with septic shock.84 As in earlier studies, the authors performed corticotropin tests on these patients to document and
stratify patients by relative adrenal insufficiency. In this study, 7-day
treatment with low doses of hydrocortisone and fludrocortisone
significantly and safely lowered the risk of death in patients with septic
shock and relative adrenal insufficiency. In an international, multicenter,
randomized trial of corticosteroids in sepsis (CORTICUS study; 499 analyzable
patients), steroids showed no benefit in intent to treat mortality or shock
reversal.85 This study suggested that
hydrocortisone therapy cannot be recommended as routine adjuvant therapy for
septic shock. However, if SBP remains less than 90 mmHg despite
appropriate fluid and vasopressor therapy,
hydrocortisone at 200 mg/day for 7 days in four divided doses or by continuous
infusion should be considered.
·
Right ventricular
end-diastolic volume index (RVEDVI) seems to more accurately predict
preload for cardiac index than does pulmonary artery wedge pressure.110
Chang and colleagues reported that 50% of trauma patients had persistent splanchnic ischemia that was reversed by increasing RVEDVI.
RVEDVI is a parameter that seems to correlate with preload-related increases in
cardiac output. More recently, these authors have described left ventricular
power output as an endpoint (LVP >320 mmHg·L/min
per square meter), which is associated with improved clearance of base deficit
and a lower rate of organ dysfunction following injury.
·
Natural orifice transluminal endoscopic surgery (NOTES) is a
recent extension of interventional endoscopy. Using the mouth, the anus, the
vagina, and the urethra (natural orifices), flexible endoscopes are passed through the wall of the esophagus, stomach,
colon, bladder, or vagina entering the mediastinum,
the pleural space, or the peritoneal cavity. The advantage of this method of
minimal access is principally the elimination of the scar associated with
laparoscopy or thoracoscopy. Other advantages are yet
to be elucidated, including pain reduction, need for hospitalization, and cost
savings. The first case of transvaginal
removal of a normal appendix has recently been reported.
·
The anabolic steroid oxandrolone has been extensively
studied in pediatric patients as well, and has demonstrated improvements in lean body mass and bone density in
severely burned children.100 The weight gain and functional
improvements seen with oxandrolone may persist even
after stopping administration of the drug.101 A recent double-blinded,
randomized study of oxandrolone showed decreased
length of stay, improved hepatic protein synthesis, and no adverse effects on
the endocrine function, although the authors noted a rise in transaminases with unclear clinical significance
·
Recently, a dietary supplemental regimen of arginine, -hydroxy--methylbutyrate, and glutamine was found to
significantly and specifically enhance collagen
deposition in elderly, healthy human volunteers when compared to an isocaloric, isonitrogenous
supplement. As increases in breaking strength during the first weeks of healing
are directly related to new collagen synthesis, arginine
supplementation may result in an improvement in wound strength as a consequence
of enhanced collagen deposition.
·
Germline mutations in
the hCHK2 gene
have recently been identified as another susceptibility gene for LFS. The hCHK2 gene encodes for the human
homologue of the yeast Cds1 and the RAD53 G2 checkpoint, whose
activation by DNA damage prevents entry into mitosis. CHK2 directly phosphorylates p53, which suggests that CHK2 may be
involved in p53 regulation after DNA damage. CHK2 also regulates BRCA1
function after DNA damage. The protein truncation mutation 1100delC in exon 10 identified in LFS and breast cancer abolishes the kinase function of CHK2. Another reported mutation in hCHK2
is a missense mutation (R145W) that destabilizes the
protein, shortening its half-life.
·
The prognostic implications of detection of CTCs
by RT-PCR have been intensively studied for melanoma. In the recent multicenter
Sunbelt Melanoma Trial, serial RT-PCR
was performed on peripheral blood samples using four markers—tyrosinase, melanoma antigen reacting to T cell (MART-1), melanoma
antigen 3 (MAGE3), and gp 100—to detect
occult melanoma cells in the bloodstream.98 Although there were no
differences in survival between patients in whom at least one marker was
detected and those in whom no markers were detected, the disease-free survival
and distant disease-free survival were worse for patients in whom more than one
marker was detected at any time during follow-up.98 The detection of
occult cancer cells with RT-PCR remains investigational, however, and is not
used to direct therapy for melanoma and other cancer types at this time.
·
Comparisons of the mAb
directed against the alpha chain of LFA-1 (odulimomab) with antithymocyte
immunoglobulin as induction therapy found, at 3 and 12 months after
transplantation, similar rate and severity of rejection episodes as well as
incidence of infection. An anti–LFA-1 mAb (efalizumab) was found
capable of inhibiting lymphocyte adhesion, circulation, and activation. Another
potential benefit of anti-LFA mAbs observed in both
animal models and human beings is that they can diminish the
ischemia-reperfusion injury associated with delayed graft function. The
anti-CD4 mAb (priliximab) already has shown
immunosuppressive potential in some therapeutic pilot studies.
·
A recent advance in EEG monitoring is the use of
the bispectral index (BIS) to titrate the level of sedative medications. Although
sedative drugs usually are titrated to the clinical neurologic examination, the
BIS device has been used in the operating room to continuously monitor the
depth of anesthesia. The BIS is an empiric measurement statistically derived
from a database of more than 5000 EEGs.88 The BIS is derived from bifrontal EEG recordings and analyzed for burst suppression
ratio, relative alpha:beta
ratio, and bicoherence. Using a multivariate
regression model, a linear numeric index (BIS) is calculated, ranging from 0 (isoelectric EEG) to 100 (fully awake). Its use has been
associated with lower consumption of anesthetics during surgery and earlier
awakening and faster recovery from anesthesia.89 The BIS also has
been validated as a useful approach for monitoring the level of sedation for
ICU patients, using the revised Sedation-Agitation Scale as a gold standard.
·
Esophageal Impedance:
An intraluminal electrical impedance catheter has recently
been developed for the measurement of GI function. Impedance is the
ratio of voltage to current, and is a measure of the electrical conductivity of
a hollow organ and its contents. Intraluminal
electrical impedance is inversely proportional to the electrical conductivity
of the luminal contents and the cross-sectional area of the lumen. Air has a
very low electrical conductivity and, therefore, high impedance. Saliva and
food cause an impedance decrease because of their increased conductivity.
Luminal dilatation results in a decrease in impedance, whereas luminal
contraction yields an impedance increase.
Esophageal
impedance has been validated as an appropriate method for the evaluation of GI
function and is becoming increasingly used for the diagnosis of gastroesophageal reflux.
Impedance
pH may be particularly useful in evaluating patients with persistent symptoms
despite PPI treatment, patients with respiratory symptoms, and postoperative
patients who are having symptoms that are elusive to diagnosis
·
The recent development of a wireless capsule,
which can be implanted in the esophagus and record pH data for 48 hours, has
significantly changed patient satisfaction with the procedure.
The Bravo pH Capsule (Medtronics,
Minneapolis, Minn) measures pH levels in the
esophagus and transmits continuous esophageal pH readings to a receiver worn on
the patient's belt or waistband. Symptoms that the patient experiences are recorded in a diary
and/or by pressing buttons on the receiver unit. Generally, 48 hours of
pH data are measured with this probe. A recent study has shown that the
addition of a second day of pH monitoring increased the sensitivity of pH
measurement by 22%. The capsule eventually detaches and passes through the
digestive tract in 5 to 7 days.
·
The MammaPrint
test was recently approved by the FDA for use in patients with newly
diagnosed, node-negative breast cancer. The MammaPrint
test is based on a 70-gene profile, and fresh tissue is required to perform the
assay. The Oncotype DX assay is performed using paraffin-embedded
tumor tissue and therefore can be carried out on archived samples.
·
Desmoid tumors have recently been shown to possess
alterations in the adenomatous polyposis
coli/-catenin pathway, and cyclin D1 dysregulation is thought to play a significant role in
their pathogenesis.129 Associations with other diseases and
conditions are well documented, especially those with similar alterations in
the adenomatous polyposis
coli pathway, such as familial adenomatous polyposis (Gardner's syndrome). Other conditions with
increased risk of desmoid tumor formation include
states of increased estrogen levels (pregnancy) and trauma. Surgical incisions
(abdominal and thoracic) have been the site of desmoid
development, either in or near the scar.
·
Zero-balance ultrafiltration (Z-BUF) is a method of ultrafiltration during CPB. This technique removes
significant amounts of inflammatory mediators associated with CPB and
potentially attenuates the adverse effects of bypass while maintaining the
patient's volume status. Recent studies have shown that Z-BUF reduces pulmonary
edema and protects against lung injury.6 Additionally,
the use of Z-BUF has been shown to decrease the
concentrations of interleukin-6 and interleukin-8 that are markers of systemic
inflammation associated with CPB.
·
A total
artificial heart (TAH) will be the conceptual end solution for
cardiac replacement of the failing heart. This technology has moved in a vastly
different direction than VADs. Assist devices work in parallel to the left
ventricle, and are becoming simpler, smaller, and valveless,
in contrast to the TAH, which displaces the heart and retains pulsatile flow. The original Jarvik
TAH is still in use as the CardioWest BiVAD and is used as a bridge to transplant. More recently,
the AbioCor TAH has been implanted as part of an FDA
trial and recently obtained FDA Humanitarian Device Exemption approval in 2006.
·
Loeys-Dietz syndrome is phenotypically
distinct from Marfan syndrome. It is characterized as
an aneurysmal syndrome with widespread systemic
involvement. Loeys-Dietz syndrome is an aggressive, autosomal dominant condition that is distinguished by the
triad of arterial tortuosity
and aneurysms, hypertelorism (widely spaced eyes),
and bifid uvula or cleft palate. It is caused by heterozygous mutations
in the genes encoding TGF- receptors,
rather than fibrillin 1.
·
Unfortunately, laboratory studies are of little
help in diagnosing acute aortic dissection. There has been recent interest in
using D-dimer
level to aid in making this diagnosis. Several reports have demonstrated that
D-dimer is an extremely sensitive indicator of acute aortic dissection; elevated levels are
found in approximately 97% of affected patients.
·
However, the majority of TIAs resolve within
minutes, and longer lasting neurologic deficits more likely represent a stroke.
Recently, the term brain attack
has been coined to refer to an acute stroke or TIA, denoting the condition as a
medical emergency requiring immediate attention, similar to a heart attack.
·
Recently, it has been noted that the anorexigenic hormone leptin, secreted mostly by fat but also
by gastric mucosa, inhibits gastric emptying, perhaps through the same pathway
as CCK (which also has properties of a satiety hormone). The orexigenic hormone ghrelin has the opposite effect
·
There are two clinical syndromes characterized
by epithelial hyperplasia and giant gastric folds: ZES and Ménétrier's
disease. The latter is characteristically associated with protein-losing gastropathy and hypochlorhydria.
There are large rugal folds in the proximal stomach,
and the antrum is usually spared. Mucosal biopsy
shows diffuse hyperplasia of the surface mucus-secreting cells and usually
decreased parietal cells. It has recently been suggested that Ménétrier's disease is caused by local overexpression
of transforming growth factor alpha in the gastric mucosa, which
stimulates the epidermal growth factor receptor, a receptor tyrosine kinase, on gastric SECs. This results in the selective
expansion of surface mucous cells in the gastric body and fundus.
A few patients with this unusual disease have been successfully treated with
the epidermal growth factor receptor blocking monoclonal antibody cetuximab.
·
AFAP (Attenuated
FAP) is a recently recognized variant of FAP associated with
mutations at the 3' or 5' end of the APC gene. Patients present later in life
with fewer polyps (usually 10 to 100) dominantly located in the right colon, when
compared to classic FAP. Colorectal carcinoma develops in more than 50% of
these patients, but occurs later (average age 55 years). Patients are also at
risk for duodenal polyposis. However, in contrast to
FAP, APC gene mutations are present in only about 30% of patients with AFAP.
When present, these mutations are expressed in an autosomal
dominant pattern.
·
Recent studies have shown that a fifth islet
peptide, ghrelin,
is secreted from a distinct population of islet cells, called epsilon cells.15,16 Ghrelin also is present in the gastric fundus
in large amounts and stimulates growth hormone secretion via growth hormone
releasing hormone release from the pituitary. It is an orexigenic,
or appetite-stimulating, peptide the plasma levels of which are increased in
obesity. Ghrelin has also been shown to block insulin
effects on the liver, and inhibits the -cell
response to incretin hormones and glucose.17
Therefore, ghrelin secretion from and within the
islet may modulate the responses of other islet cells to nutrient and hormonal
stimuli.
Amylin or islet amyloid
polypeptide (IAPP) is a 37-amino-acid polypeptide that was discovered in 1988. IAPP is predominantly expressed by the pancreatic -cells,
where it is stored along with insulin in secretory
granules.18 The function of IAPP seems to be the modulation or counterregulation of insulin secretion and function. Pancreastatin is
a recently discovered pancreatic islet peptide product that inhibits insulin,
and possibly somatostatin release, and augments
glucagon release
·
Recent studies also indicate that Toll-like
receptor 4 (TLR4) is significant in
determining the severity of acute pancreatitis.
The TLR4 initiates a complex signaling pathway when it interacts with lipopolysaccharides that result in a proinflammatory
response. Mice in which TLR4 is genetically deleted have significantly reduced
pancreatitis; this suggests that TLR4 is a significant promoter of proinflammation. However, this effect appears independently
of lipopolysaccharides and is probably mediated by a
hitherto unknown TLR4 agonist. It is likely that TLR4 antagonists would be a
good therapy against pancreatitis.
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