Dextran Carrier Macromolecules for Colon-specific Delivery of 5-Aminosalicylic Acid

Present manuscript describes the sustained and targeted delivery of 5-aminosalicylic acid to the distal ileum and proximal colon, using dextran (40 kDa) as a carrier for targeting 5-aminosalicylic acid at the colonic site by attaching p-aminobenzoic acid and benzoic acid as linkers. Prepared conjugate were characterized by UV, HPLC, FT-IR, and ¹H NMR. The degree of substitution was estimated by complete hydrolysis of conjugates in borate buffer and in vitro hydrolysis study of conjugates was performed in different biological media. It was observed that 5-aminosalicylic acid alone have produced high incidence of gastric ulcer with high ulcer index whereas lower ulcer index was found for the dextran conjugates of 5-aminosalicylic acid. The release pattern of conjugates in 3% w/v rat caecal content was confirmed the colon specificity of 5-aminosalicylic acid conjugates.

Pro-inflammatory and anti-inflammatory cytokine response in diarrhoea-predominant irritable bowel syndrome patients

BACKGROUND AND AIM

Irritable bowel syndrome (IBS) is referred to as a functional bowel disorder which is diagnosed by a number of characteristic symptoms (Rome II criteria) in the absence of detectable structural abnormalities. Low-grade inflammation of the intestine may be one of the reasons for development of diarrhoea-predominant IBS (IBS-D). We undertook this study to estimate the serum levels of pro-inflammatory (IL-6, TNF-alpha) and anti-inflammatory (IL-10) cytokines in IBS-D patients.

METHODS

A total of 108 diarrhoea patients were screened. Out of these only 63 adult IBS-D patients were enrolled. Age and sex matched 62 apparently healthy controls with no GI symptoms were also recruited. Out of 63 IBS-D patients, 37 were males while there were 32 males among the controls. The patients with IBS-D were diagnosed according to the Rome II criteria. Levels of serum IL-6, TNF-alpha and IL-10 were measured in all subjects using ELISA.

RESULTS

Mean (+/- SD) age of IBS-D patients (42.6 +/- 19.5 years) was comparable (p = 0.64) to that of controls (43.5 +/- 18.7 years). The mean (+/- SD) levels of IL-6 in IBS-D patients (32.2 +/- 12.01 pg/ml) was significantly higher (p < 0.001) than in controls (7.48 +/- 2.55 pg/ml). The levels of TNF-alpha in IBS-D patients (16.3 +/- 5.2 pg/ml) were also significantly higher (p < 0.05) than in controls (7.94 +/- 2.19 pg/ml). There was no significant difference in the serum levels of IL-10 (p = 0.23) between IBS-D patients (5.75 +/- 2.1 pg/ml) and controls (5.84 +/- 1.9 pg/ml).

CONCLUSION

Our results indicate that mild inflammation is involved in IBS-D patients as proinflammatory cytokines were increased although no difference in anti-inflammatory cytokine was observed.

Small intestinal bacterial overgrowth and orocecal transit time in patients of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) consists of Ulcerative colitis (UC) and Crohn's disease (CD). These two conditions share many common features-diarrhea, bloody stools, weight loss, abdominal pain, fever and fatigue. Small intestinal bacterial overgrowth (SIBO) is frequent in patients with CD but it has not been studied in UC Indian patients.

AIM

The study was planned to measure orocecal transit time (OCTT) and SIBO in UC and CD patients.

METHODS

One hundred thirty-seven patients of IBD (95 UC and 42 CD) and 115 healthy controls were enrolled. OCTT and SIBO were measured by lactulose and glucose hydrogen breath test respectively. Concentration of hydrogen and methane were measured by SC microlyser from Quintron, USA.

RESULTS

Mean±standard deviation (SD) of OCTT in patients of IBD was significantly higher as compared to controls. Furthermore, OCTT was significantly higher in CD patients as compared to UC patients. It was also observed that occurrence of SIBO was significantly higher in IBD patients as compared to controls. The occurrence of SIBO in CD (45.2%) was significantly higher as compared to patients in UC (17.8%) group. Percentage of methane positive IBD patients (2.9%) was significantly lower as compared to methane positive controls (24.4%).

CONCLUSION

OCTT was significantly delayed in IBD patients as compared to controls and in CD patients as compared to UC patients. OCTT was significantly higher in SIBO positive IBD patients as compared to SIBO negative patients. Thus, we can suggest that delayed OCTT would have been the cause of increased SIBO in these patients.

Multiplex PCR for rapid diagnosis of gastrointestinal tuberculosis

Background:

Rapid and specific diagnosis of gastrointestinal tuberculosis (GITB) is of utmost importance.

Aim:

To evaluate Multiplex PCR (MPCR) using MPB64 and IS6110 primers specific for M. tuberculosis for rapid diagnosis of GITB.

Materials and Methods:

MPCR was performed on colonoscopy biopsy specimens on 11 GITB confirmed (culture/AFB/histopathology was positive), 29 GITB suspected and 30 Non GITB (control group) patients.

Results:

MPB64 PCR had sensitivity and specificity of 90% and 100% for confirmed GITB cases. In 29 clinically diagnosed but unconfirmed GITB cases, MPCR was positive in 72.41%. MPCR was negative in all control group patients. The overall sensitivity and specificity of microscopy, culture, histopathology and MPCR was 5%, 2% 20% and 77.5% and 100%, 100%, 100% and 100% respectively.

Conclusion:

MPCR has good sensitivity and specificity in diagnosing gastrointestinal tuberculosis.

Jamming behavior of domains in a spiral antiferromagnetic system

Using resonant magnetic x-ray photon correlation spectroscopy, we show that the domains of a spiral antiferromagnet enter a jammed state at the onset of long-range order. We find that the slow thermal fluctuations of the domain walls exhibit a compressed exponential relaxation with an exponent of 1.5 found in a wide variety of solidlike jammed systems and can be qualitatively explained in terms of stress release in a stressed network. As the temperature decreases, the energy barrier for fluctuations becomes large enough to arrest further domain wall fluctuations, and the domains freeze into a spatial configuration within 10 K of the Néel temperature. The relaxation times can be fitted with the Vogel-Fulcher law as observed in polymers, glasses, and colloids, thereby indicating that the dynamics of domain walls in an ordered antiferromagnet exhibit some of the universal features associated with jamming behavior.

Clinical presentation and outcome of endoscopic therapy in patients with symptomatic chronic pancreatitis associated with pancreas divisum

CONTEXT

The results of endoscopic drainage in pancreas divisum with chronic pancreatitis have been debatable.

OBJECTIVE

To evaluate clinical presentation and long term results of endoscopic therapy in patients of calcific and non-calcific chronic pancreatitis with pancreas divisum.

PATIENTS AND METHODS

Between 1996 and 2011, 48 patients (32 males and 16 females) with chronic pancreatitis and pancreas divisum were treated endoscopically. Patients were considered to have clinical success if they had resolution of symptoms and did not require surgery.

RESULTS

All patients presented with abdominal pain and symptoms were present for 36.6 ± 40.5 months. Pseudocyst, diabetes, pancreatic ascites, pancreatic pleural effusion, segmental portal hypertension and steatorrhea were seen in 13 (27.1%), 6 (12.5%), 3 (6.3%), 2 (4.2%), 2 (4.2%) and 1 (2.1%) patients, respectively. Ductal calculi and strictures were noted in 3 (6.3%) and 2 (4.2%) patients, respectively. In 47 patients, an endoprosthesis (5 or 7 Fr) was successfully placed in the dorsal duct. Following pancreatic endotherapy, 45/47 (95.7%) patients had successful outcome. The mean number of stenting sessions required to have clinical success was 2.6 ± 0.9. One patient each had mild post ERCP pancreatitis, inward migration of stent and precipitation of diabetic ketoacidosis. Over a follow up of 2-174 months (median: 67 months), 12 out of 31 patients with pain only and no local complications (38.7%) required restenting for recurrence of pain and none of these patients required surgery.

CONCLUSION

Intensive pancreatic endotherapy is safe and effective both in patients with chronic calcific, as well as non-calcific, pancreatitis associated with pancreas divisum. It gives good long term response in patients having abdominal pain and/or dorsal ductal disruptions.

Diastolic dysfunction, prolonged QTc interval and pericardial effusion as predictors of mortality in acute pancreatitis

BACKGROUND AND AIM

The cardiac changes in acute pancreatitis have been earlier studied but the data on their prognostic significance is limited. This study was done to determine electrocardiographic (ECG) and echocardiographic changes in acute pancreatitis and determine their prognostic significance.

METHODS

Fifty-two consecutive patients (mean age 36.5 ± 11 years (44 males)) with acute pancreatitis and without prior cardiovascular comorbidites were prospectively enrolled and subjected to clinical, laboratory and radiological investigation. ECG and echocardiography was done at admission and during follow up.

RESULTS

Seventeen patients (32.7%) had mild pancreatitis and 35 (67.3%) patients had severe pancreatitis. Sinus tachycardia was the most common ECG abnormality. QTc prolongation was seen in 30/52 (57.7%) patients. On echocardiography, no patient had systolic dysfunction but 31/52 (59.6%) patients had diastolic dysfunction. All 22 patients with QTc interval < 440 ms survived compared with 8/30 patients with QTc interval ≥ 440 ms who died (P = 0.01). All eight patients who died had evidence of diastolic dysfunction (100%). None of the patients without diastolic dysfunction succumbed to illness (P = 0.02). Pericardial effusion was present in 6/52 (11.5%) patients. Of the eight patients who died, pericardial effusion was present in three (37.5%) patients and this frequency was significantly higher than that in patients who recovered (3/44 [6.8%]; P = 0.04).

CONCLUSION

Electrocardiographic and echocardiographic changes are seen in more than 50% of patients with acute pancreatitis. Prolonged QTc interval, pericardial effusion and diastolic dysfunction are associated with higher mortality.

Comparison of lactulose and glucose breath test for diagnosis of small intestinal bacterial overgrowth in patients with irritable bowel syndrome

BACKGROUND AND AIMS

Validity of the lactulose breath test (LBT) to diagnose small intestinal bacterial overgrowth (SIBO) has been questioned. Therefore, a study was planned to compare LBT with glucose breath test (GBT) to diagnose SIBO in irritable bowel syndrome (IBS) patients and controls.

METHODS

175 diarrhea-predominant IBS patients and 150 apparently healthy controls were enrolled. IBS was diagnosed according to Rome II criteria. Breath samples were collected every 10 min up to 180 min. Breath H₂ and CH₄ were measured using an SC MicroLyzer. SIBO was positive with a sustained increase in breath H₂ or CH₄ or both ≥10 ppm over a baseline value within <90 min in case of LBT and within <120 min in GBT.

RESULTS

SIBO was positive in 60/175 (34.3%) patients by lactulose and in 11/175 (6.2%) patients by GBT. In controls, LBT was positive for SIBO in 45/150 (30%) patients and in 1/150 (0.66%) patients by GBT. Positive LBT for SIBO was not significantly different in patients and controls; while using GBT, SIBO was significantly higher (p < 0.01) in patients as compared to controls. By using GBT as gold standard for SIBO, sensitivity, specificity, positive predictive value and negative predictive value of LBT in IBS patients was 63.6, 67.7, 11.7 and 96.6% respectively.

CONCLUSION

LBT is not a good test to discriminate SIBO in IBS patients from controls.

Integration of tobacco cessation in general medical practice: need of the hour

Tobacco use is the single most preventable cause of death and disability. Tobacco use causes almost one million deaths annually in India, which is much more than the combined mortality due to malaria/TB and HIV/AIDS. It is estimated to cause one billion deaths in the 21st century, eighty per cent of which will occur in the developing countries like India. Tobacco use is increasing in the country. Global Adult Tobacco Survey, 2010, estimated that more than one-third of adults (35%) in the country use tobacco, out of which 21% use smokeless tobacco, 9% smoke and 5% use both. The prevalence of overall tobacco use among men was 47.9% and among women was 20.2%. Global Youth Tobacco Survey, India, 2009, estimate 14.6% of 13-15 years school going children use tobacco. There is urgent need for addressing the tobacco epidemic in India. Though effective interventions for tobacco cessation such as brief counselling, nicotine replacement therapy, non-nicotine pharmacotherapy are available, their use by general practitioners is restricted due to lack of adequate dissemination of information in their use. Use of these simple assessment tools and practice of these effective interventions by general medical and healthcare practitioners will go a long way in addressing the rising tobacco epidemic in India and making general healthcare more comprehensive.

Impact of an irreversibly adsorbed layer on local viscosity of nanoconfined polymer melts

We report the origin of the effect of nanoscale confinement on the local viscosity of entangled polystyrene (PS) films at temperatures far above the glass transition temperature. By using marker x-ray photon correlation spectroscopy with gold nanoparticles embedded in the PS films prepared on solid substrates, we have determined the local viscosity as a function of the distance from the polymer-substrate interface. The results show the impact of a very thin adsorbed layer (~7 nm in thickness) even without specific interactions of the polymer with the substrate, overcoming the effect of a surface mobile layer at the air-polymer interface and thereby resulting in a significant increase in the local viscosity as approaching the substrate interface.

Comparison between acetylator phenotype and genotype polymorphism of n-acetyltransferase-2 in tuberculosis patients

BACKGROUND

Isoniazid (INH) is one of the most important drugs of antitubercular treatment regime, and in some cases it causes hepatotoxicity. It is metabolized by hepatic N-acetyltransferase-2 (NAT2).

AIM

To compare whether both methods, i.e., genotype NAT2 and phenotype test of measuring serum INH levels, are useful to identify acetylator status of patients on antitubercular treatment (ATT).

METHODS

A total of 251 tuberculosis (TB) patients on standard treatment were followed up to 6 months for this study. NAT2 genotype was assessed by PCR with restriction fragment length polymorphism (RFLP) whereas serum INH levels were measured by fluorometry.

RESULTS

Of the 251 patients, 50 (19.9%) developed ATT-induced hepatotoxicity. By phenotypic estimation, in the hepatotoxicity group, 17/50 (34%) were slow acetylators whereas 33/50 (66%) were fast acetylators. Genotypically, 19/50 (38%) were slow acetylators and 31/50 (62%) fast acetylators. By phenotypic analysis, in non-hepatotoxicity group, 46/201 (22.9%) were slow acetylators and 155/201 (77.1%) fast acetylators. By genotypic analysis, 30/201 (14.9%) were slow acetylators and 171/201 (85%) fast acetylators. Overall, slow acetylators (25.1%) measured phenotypically were not significantly different from slow acetylators (19.5%) measured genotypically.

CONCLUSION

This study suggests that the acetylator status of TB patients can be detected by phenotypic method as efficaciously as by genotypic method. Therefore, phenotypic method can replace genotypic method to determine acetylating status as phenotypic method is simple and inexpensive.

Evaluation of the effectiveness of ophthalmic assistants as screeners for glaucoma in North India

AIM

To assess whether ophthalmic assistants are effective in screening people for glaucoma in India.

METHODOLOGY

The study subjects were examined by both trained ophthalmic assistants and an ophthalmologist in both hospital and community settings. Specific tests for the diagnosis of glaucoma suspects included visual field examination using frequency doubling technology perimetry, intraocular pressure measurement (Tonopen), A-scan central anterior chamber depth measurement and dilated optic disc examination. The findings recorded by the ophthalmic assistants were masked to the ophthalmologist to avoid measurement bias.

RESULTS

In the hospital setting, there was a substantial level of agreement between the ophthalmic assistants and the ophthalmologist in the diagnosis of glaucoma suspects (89.29%, k=0.7, 95% confidence interval (CI)=0.54-0.86). The diagnostic accuracy of the ophthalmic assistants in detecting glaucoma suspects was high for sensitivity (95.2%, 95% CI=91.4-97.7%) but lower for specificity at 71.4% (95% CI=60.0-78.7%).In the community setting, there was a moderate level of agreement between the ophthalmic assistants and the ophthalmologist in the diagnosis of glaucoma suspects (78.23%, k=0.50, 95% CI=0.37-0.64). The diagnostic accuracy of the ophthalmic assistants in detecting glaucoma suspects was moderate for sensitivity (82.9, 95% CI=69.7-91.5%) but lower for specificity at 76.8% (95% CI=72.7-79.5%).

CONCLUSION

Ophthalmic assistants can be used for opportunistic case detection of glaucoma suspects in the community. Structured training of the ophthalmic assistants together with enhanced clinical experience would improve their performance in detecting glaucoma suspects in the community.

Pseudothrombocytopenia -- a caveat

Pseudothrombocytopenia is an ex vivo thrombocytopenia, counted by an automated cell counter, but not configured by microscopic examination of a well prepared blood smear. Incidences of pseudothrombocytopenia reported in different studies range from 0.09-0.21%, which could account for 15-30% of all cases of thrombocytopenla. Failure to identify pseudothrombocytopenia has led to a lot of clinical problems like unnecessary platelet transfusion, glucocorticoid therapy and so on. Haematological cell counters count platelets as particles with volume between 2 and 20fl. Thus platelet clumps are counted as leucocytes while fragmented RBCs as platelets. This study found pseudothrombocytopenia due to causes like EDTA blood stored at less than 32 degrees C for more than 2 hours (35%), excess EDTA in sample (10.7%), hyperlipidaemia, auto-immune disease, pregnancy, etc. No apparent cause could be found in 52% of cases. Hence it is emphasised that direct microscopic examination of a well stained blood smear from EDTA-venous blood (within 1hour) and or direct counting under Neubauer chamber with 1% ammonium oxalate (in special cases) is almost mandatory before releasing a report of platelet count. Also factors related to ratio and storage of EDTA-blood, calibration of instruments, proper selection of reagents, supervision of laboratory staff are essential to rule out any error of report including pseudothrombocytopenia.

Liver pathology in collagen vascular disorders highlighting the vascular changes within portal tracts

BACKGROUND

Collagen vascular disorders (CVDs) are autoimmune disorders with multisystem involvement. Clinical liver involvement is not a characteristic feature though histological involvement could be frequent. Liver disease in CVDs could be the consequence of various factors.

AIM

The aim was to analyze the histological spectrum of liver in collagen vascular disorders (CVDs) at autopsy.

MATERIALS AND METHODS

Thirty-six autopsy livers negative for hepatitis B or C virus were studied in CVD cases with no known association with chronic liver disease or vascular thrombosis or hematological disorder. Cirrhotic and normal livers were used as controls. The paired t-test, one-way ANOVA, and two-sided Dunnett t-test were used for comparison (< 0.05). None of the control cases showed any abnormal vessels.

RESULTS

There were 21 systemic lupus erythematosus (SLE), 7 rheumatoid arthritis (RA), 5 systemic sclerosis (SSc), and 3 polyarteritis nodosa (PAN) cases (M:F = 11:25, age range 23-60 years).

HISTOLOGY

Diffuse nodular regenerative hyperplasia of liver (NRHL) was seen in 10 cases, and 6 (5 SLE and 1 RA) had numerous abnormal thin-walled vessels in intermediate- and small-sized portal tracts with no vascular occlusion or inflammation. Moderate sized portal tracts showed more interface and lobular inflammation. The main portal vein and its major branches were normal. None of these six cases had increased transmainases (P>0.05). Most SLE cases had increased transaminases (P<0.05). No evidence of portal hypertension was seen in all except in one RA. Septicemia is known to be associated with raised transaminases.

CONCLUSION

A rare pathology of conglomerate of abnormal vessels in intermediate- and small-sized portal system was observed co-existing with NRHL in CVDs. Raised liver enzyme with interface hepatitis in CVD may not necessarily warrant an overlap, as a similar feature could be observed in septicemia.

Molecular simulation of the frictional behavior of polymer-on-polymer sliding

Molecular simulations of the sliding processes of polymer-on-polymer systems were performed to investigate the surface and subsurface deformations and how these affect tribological characteristics of nanometer-scale polymer films. It is shown that a very severe deformation is localized to a band of material about 2.5 nm thick at the interface of the polymer surfaces. Outside of this band, the polymer films experience a uniform shear strain that reaches a finite steady-state value of close to 100%. Only after the polymer films have achieved this steady-state shear strain do the contacting surfaces of the films show significant relative slippage over each other. Because severe deformation is limited to a localized band much thinner than the polymeric films, the thickness of the deformation band is envisaged to be independent of the film thickness and hence frictional forces are expected to be independent of the thickness of the polymer films. A strong dependency of friction on interfacial adhesion, surface roughness, and the shear modulus of the sliding system was observed. Although the simulations showed that frictional forces increase linearly with contact pressure, adhesive forces contribute significantly to the overall friction and must therefore be accounted for in nanometer-scale friction. It is also shown that the coefficient of friction is lower for lower-density polymers as well as for polymers with higher molecular weights.

Measurement of the interior structure of thin polymer films using grazing incidence diffuse x-ray scattering

A method is developed for calculating the small-angle x-ray scattering originating from within the interior of a thin film under grazing incidence illumination. This offers the possibility of using x-ray scattering to probe how the structure of polymers is modified by confinement. When the diffuse scattering from a thin film is measured over a range of incident angles, it is possible to separate the contributions to scattering from the interfaces and the contribution from the film interior. Using the distorted-wave Born approximation the structure factor, S(q), of the film interior can then be obtained. We apply this method to analyze density fluctuations from within the interior of a silicon supported molten polystyrene (PS) film. Measurements were made as a function of film thickness ranging from one to ten times the polymer radius of gyration (Rg). The compressibility, calculated by extrapolating the measured S(q) to q=0, agrees well with that of bulk PS for thick films, but thinner films exhibit a peak in S(q) near q=0. This peak, which grows with decreasing thickness, is attributed to a decreased interpenetration of chains and a consequent enhanced compressibility.

Reduced viscosity of the free surface in entangled polymer melt films

By embedding "dilute" gold nanoparticles in single polystyrene thin films as "markers", we probe the local viscosity of the free surface at temperatures far above the glass transition temperature (T(g)). The technique used was x-ray photon correlation spectroscopy with resonance-enhanced x-ray scattering. The results clearly showed the surface viscosity is about 30% lower than the rest of the film. We found that this reduction is strongly associated with chain entanglements at the free surface rather than the reduction in T(g).

Endoscopic management of pancreatic pseudocysts at atypical locations

BACKGROUND AND AIMS

There is paucity of data on endoscopic management of pseudocysts at atypical locations. We evaluated the efficacy of endoscopic transpapillary nasopancreatic drain (NPD) placement in the management of pseudocysts of pancreas at atypical locations.

PATIENTS AND METHODS

Eleven patients with pseudocysts at atypical locations were treated with attempted endoscopic transpapillary nasopancreatic drainage. On endoscopic retrograde pancreatography (ERP), a 5-F NPD was placed across/near the site of duct disruption.

RESULTS

Three patients each had mediastinal, intrahepatic, and intra/perisplenic pseudocysts and one patient each had renal and pelvic pseudocyst. Nine patients had chronic pancreatitis whereas two patients had acute pancreatitis. The size of the pseudocysts ranged from 2 to 15 cm. On ERP, the site of ductal disruption was in the body of pancreas in five patients (45.4%), and tail of pancreas in six patients (54.6%). All the patients had partial disruption of pancreatic duct. The NPD was successfully placed across the disruption in 10 of the 11 patients (90.9%) and pseudocysts resolved in 4-8 weeks. One of the patients developed fever, 5 days after the procedure, which was successfully treated by intravenous antibiotics. In another patient, NPD became blocked 12 days after the procedure and was successfully opened by aspiration. The NPD slipped out in one of the patient with splenic pseudocyst and was replaced with a stent. There was no recurrence of symptoms or pseudocysts during follow-up of 3-70 months.

CONCLUSION

Pancreatic pseudocysts at atypical locations with ductal communication and partial ductal disruption that is bridged by NPD can also be effectively treated with endoscopic transpapillary NPD placement.

Pancreaticopleural fistula: an unusual complication of pancreatitis diagnosed with magnetic resonance cholangiopancreatography

CONTEXT

Pancreaticopleural fistula is a rare complication of pancreatitis. Pleural effusion resulting from a pancreaticopleural fistula is extremely rare and accounts for less than 1% of cases. Due to non-specific clinical presentations of a pancreaticopleural fistula, imaging plays an important role. Magnetic resonance cholangiopancreatography (MRCP) is very useful in depicting parenchymal and ductal structural changes along with direct visualization of a pancreaticopleural fistula.

CASE REPORT

We present the case of a middle-aged male with moderate right pleural effusion who had a history of pancreatitis. MRCP showed chronic pancreatitis with a pancreaticopleural fistula. A brief review of the role of imaging in a pancreaticopleural fistula is discussed along with the case.

CONCLUSION

MRCP is a useful modality for diagnosing a pancreaticopleural fistula.

Association of alpha 2A adrenergic receptor gene (ADRAlpha2A) polymorphism with irritable bowel syndrome, microscopic and ulcerative colitis

BACKGROUND

Alpha 2 adrenergic receptors (alpha2 ARs) play a central role in the regulation of systemic sympathetic activity. Prejunctional alpha 2A adrenoceptor regulates through negative feedback at presynaptic nerve ending. A-1291 C>G polymorphism located in alpha2-adrenergic receptor gene (ADRAlpha2A) has been identified. We investigated the possible association between 1291 C>G polymorphism in the promoter region of ADRAlpha2A in clinical subtypes of IBS, ulcerative and microscopic colitis patients.

METHODS

This prospective case control study included 92 patients with diarrhea predominant IBS (D-IBS), 44 with constipation predominant IBS (C-IBS), 15 with alternating diarrhea and constipation IBS (M-IBS), 75 ulcerative colitis (UC), 41 microscopic colitis (MC) and 100 healthy controls. The subjects were genotyped by using PCR amplification of the promoter region of ADRAlpha2A gene followed by digestion with the restriction enzyme MspI. The study was approved by the institute ethical committee.

RESULTS

A strong genotypic association was observed between alpha2A-1291 C>G polymorphism and D-IBS (chi2=6.38, df=2, p<0.05). There was no significant difference in alpha2A-1291 C>G genotype and allele frequency between C-IBS, M-IBS, UC, MC cases and control subjects.

CONCLUSIONS

A significant association was observed between alpha2A-1291C>G polymorphism and D-IBS. Thus, alpha2 AR gene may be a potential candidate involved in the pathophysiology of D-IBS.

Long term follow-up of very low birthweight infants from a neonatal volume versus pressure mechanical ventilation trial

BACKGROUND

A previous randomised trial showed volume controlled ventilation (VCV) was efficacious in ventilating very preterm and extremely low birthweight babies.

OBJECTIVE

To compare long term survival, pulmonary morbidities and gross neurodevelopmental outcomes of babies randomised to either VCV or pressure limited ventilation (PLV) for treatment of respiratory distress syndrome.

DESIGN/METHODS

Masked evaluation of health status, including frequency of respiratory illness, use of medications, hospital admissions, and gross neurodevelopmental status were obtained using a structured parental questionnaire and verification from medical records.

RESULTS

94 of 109 children (86%) survived to discharge. Three died after discharge (2 VCV, 1 PLV). Modality of ventilation did not affect overall mortality; seven VCV children died (12%) versus 11 PLV (21%) (OR 0.5 (95% CI 0.1 to 1.4), p = 0.13). Respiratory abnormalities were present in 32 (37%), and 26 (30%) required hospital readmission. There was no significant difference in readmission rates between the two groups: VC 13/45 (29%) and PLV 19/40 (47%) (OR 0.4 (0.1 to 1.1), p = 0.07). Modality of ventilation did not affect frequency of respiratory illness: VC 12 (27%) and PLV 14 (35%) (OR 0.46 (0.1 to 1.1), p = 0.09). However, significantly fewer VCV children (13%, n = 6) compared to PLV children (32%, n = 13) required treatment with inhaled steroids/bronchodilators (OR 0.3 (0.1 to 0.9), p = 0.04). Nine children had severe neurodevelopmental disability (cerebral palsy, blindness, deafness) (9.8%; 3 VCV, 6 PLV 6) (OR 0.4 (0.09 to 1.7)).

CONCLUSIONS

The efficacy of VCV in very preterm and low birth babies appears to be maintained on longer term evaluation.