Breath tests and irritable bowel syndrome

Breath tests are non-invasive tests and can detect H2and CH4 gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath.These tests are used in the diagnosis of carbohydrate malabsorption,small intestinal bacterial overgrowth,and for measuring the orocecal transit time.Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome(IBS)-type symptoms such as diarrhea and/or constipation,bloating,excess flatulence,headaches and lack of energy.Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life.It may reflect dietary imbalance,such as excess fiber intake,or may be a manifestation of IBS.However,bloating may also represent small intestinal bacterial overgrowth.Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H2 breath testing to determine the presence or absence of bacterial overgrowth.If bacterial overgrowth is identified,patients are typically treated with antibiotics.Evaluation of IBS generally includes testing of other disorders that cause similar symptoms.Carbohydrate malabsorption(lactose,fructose,sorbitol)can cause abdominal fullness,bloating,nausea,abdominal pain,flatulence,and diarrhea,which are similar to the symptoms of IBS.However,it is unclear if these digestive disorders contribute to or cause the symptoms of IBS.Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS.Thus,diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients.     

Impact of estimated glomerular filtration rate on diabetic macular edema

Purpose

Diabetic macular edema (DME) is a major cause of visual impairment in patients with diabetes and is influenced by various systemic factors. This study evaluates the effect of renal status on DME using estimated glomerular filtration rate (eGFR) as a study marker.

Methods

This was a prospective observational cross-sectional study. One hundred and ninety-five patients of diabetic retinopathy (DR) were included. Group 1 had patients of DR without DME (n = 100), and group 2 had patients of DR with DME (n = 95). All patients were evaluated for DR/DME-related risk factors. eGFR was calculated in all patients. Spectral domain optical coherence tomography (SDOCT) was done to identify the various patterns and severity of DME.

Results

Group 2 patients had significantly higher comorbidities than those in group 1 (p < 0.001). Hba1c, total cholesterol, triglycerides, LDL/HDL ratio, systolic and diastolic blood pressures were significantly higher in group II (p < 0.001 in each). There was no significant difference between the groups in terms of blood urea, serum creatinine or eGFR. eGFR did not show a significant association with a specific SDOCT pattern or severity of DME.

Conclusion

Comorbidities are more common and more severe in patients with DME. However, eGFR as a marker was not useful in predicting either the severity or pattern of DME. eGFR, in its present form, may not be useful in the evaluation and management of patients with DME.

     

CYP1A1, CYP1A2 and CYBA gene polymorphisms associated with oxidative stress in COPD

BackgroundThe genetic susceptibility to chronic obstructive pulmonary disease (COPD) depends on detoxification and antioxidant enzymes, which detoxify cigarette smoke reactive components that, otherwise, generate oxidative stress.MethodsIn a case–control study of 346 subjects with and without COPD, we examined the polymorphisms 462Ile/Val, 3801T/C of CYP1A1, ?3860G/A of CYP1A2 and ?930A/G, 242C/T of CYBA individually or in combination and their contribution to oxidative stress markers by measuring malondialdehyde (MDA), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx).ResultsCOPD patients had significantly increased MDA concentration (p < 0.001) and decreased CAT activity, GSH concentration, GPx activity (p ≤ 0.01). The patients were over-represented by the alleles 462Val, 3801C of CYP1A1 and ?930G, 242C of CYBA (p < 0.001, p = 0.003, p = 0.030 and p = 0.031, respectively) and consequently the haplotypes of same alleles i.e. 462Val:3801C, 462Val:3801T and ?930G:242C (p = 0.048, p = 0.016 and p = 0.039, respectively). Similarly, CYP1A1 and CYP1A2 haplotypes, 462Val:3860G and 462Val:3801T:3860G were significantly over-represented (p = 0.001 and p = 0.003), respectively in patients. The same alleles-associated genotype-combinations between genes were more prevalent in patients. Of note, the genotypes, 462Ile/Val+Val/Val, 3801TC+CC of CYP1A1 and ?930AG+GG of CYBA associated with increased MDA concentration (p = 0.018, p = 0.045 and p = 0.017, respectively), decreased CAT activity (p < 0.0001, p = 0.080 and p < 0.0001, respectively) and GSH concentration (p < 0.0001, p = 0.0002 and p = 0.011, respectively) in patients.ConclusionThe identified alleles, its haplotypes and the genotype-combination along with increased oxidative stress, signify the importance in susceptibility to COPD.     

Training of nonophthalmologists in diabetic retinopathy screening

The burden of diabetes mellitus (DM) and diabetic retinopathy (DR) is at alarming proportions in India and around the globe. The number of people with DM in India is estimated to increase to over 134 million by 2045. Screening and early identification of sight-threatening DR are proven ways of reducing DR-related blindness. An ideal DR screening model should include personalized awareness, targeted screening, integrated follow-up reminders, and capacity building. The DR screening technology is slowly shifting from direct examination by an ophthalmologist to remote screening using retinal photographs, including telescreening and automated grading of retinal images using artificial intelligence. The ophthalmologist-to-patient ratio is poor in India, and there is an urban–rural divide. The possibility of screening all people with diabetes by ophthalmologists alone is a remote possibility. It is prudent to use the available nonophthalmologist workforce for DR screening in tandem with the technological advances. Capacity-building efforts are based on the principle of task sharing, which allows for the training of a variety of nonophthalmologists in DR screening techniques and technology. The nonophthalmologist human resources for health include physicians, optometrists, allied ophthalmic personnel, nurses, and pharmacists, among others. A concurrent augmentation of health infrastructure, conducive health policy, improved advocacy, and increased people''s participation are necessary requirements for successful DR screening. This perspective looks at the characteristics of various nonophthalmologist DR screening models and their applicability in addressing DR-related blindness in India.     

Retinitis pigmentosa in Laurence-Moon-Bardet-Biedl syndrome in India: Electronic medical records driven big data analytics: Report II

Purpose:To describe the clinical presentation and demographic distribution of retinitis pigmentosa (RP) in Laurence–Moon–Bardet–Biedl (LMBB) syndrome patients.Methods: This is a cross-sectional observational hospital-based study wherein 244 patients with RP in LMBB syndrome presenting to our hospital network between March 2012 and October 2020 were included. An electronic medical record database was used for data retrieval.Results: There were 244 patients in total, with a hospital-based prevalence rate of 0.010% or 1000/100,000 population. The mean and median age of patients was 15.22 ± 7.56 and 14 (IQR: 10–18.5) years, respectively, with the majority being in the age group of 11–20 years (133/244 patients; 54.50%). Males were more commonly affected (164 patients; 67.21%), and the majority (182 patients; 74.59%) were students. All 244 patients (100%) complained of defective central vision at presentation. More than one-fourth of the patients had severe visual impairment to blindness at presentation. Prominent retinal feature at presentation was diffuse or widespread retinal pigment epithelial degeneration in all patients.Conclusion: Patients with RP in LMBB syndrome present mainly in the first to second decade of life with severe visual acuity impairment to blindness early in life. It is important to rule out LMBB syndrome in early-onset RP with central visual acuity impairment. On the contrary, all patients diagnosed or suspected with LMBB syndrome systemic features at physician clinic should also be referred for ophthalmic evaluation, low vision assessment, rehabilitation, and vice versa.     

Clinical and Neuro-ophthalmologic Predictors of Visual Outcome in Idiopathic Intracranial Hypertension

Despite the potential of Idiopathic Intracranial Hypertension (IIH) to cause visual morbidity, limited literature is available focussing on predictors of visual outcome in IIH. This study was planned to assess visual morbidity in patients of IIH in terms of clinical and neuro-ophthalmo- logical parameters. In this prospective study of 40 patients of IIH, neuro-ophthalmological parameters were noted in the form of visual acuity, visual field, contrast sensitivity, Retinal Nerve Fibre Layer thickness, and visual evoked potential. Visual outcome was defined in using specific criteria. Final visual outcome of patients was compared with clinical and neuro-ophthalmologic para- meters to determine any correlation. The most common presenting clinical symptoms were headache (85%) and Transient visual obscurations (TVOs) (52.5%). In univariate analysis severity of visual loss, Cerebro Spinal Fluid (CSF) pressures and abnormal Visual evoked potential (VEP) were associated with worse visual outcome or need of aggressive management. When adjusted for severity of visual loss no independent clinical/neuroophthalmic predictor could be established. High CSF opening pressure, worsening vision/papilledema, greater Retinal Nerve Fiber Layer (RNFL) thickness and abnormal VEPs may be some of the alarming signs for physicians, but none of these parameters can be used as an independent predictor for visual outcome in isolation. Visual loss at presentation is probably the most important predictor of the final visual outcome in these patients. This may also suggest that patients presenting in an advanced disease course (with worse visual status) fair badly despite best medical/surgical management. Early diagnosis and prompt management is the cornerstone of management.     

Early abortion by mifepristone (RU 486) followed by vaginal gel (meteneprost) versus oral (misoprostol) prostaglandin

The present study was conducted to compare the therapeutic regimens of low-dose mifepristone (200 mg) plus vaginal meteneprost versus oral misoprostol in terms of efficacy and safety for medical termination of early pregnancy. A randomized clinical trial was conducted by the Department of Obstetrics and Gynecology at the All India Institute of Medical Sciences, New Delhi. A total of 101 subjects were enrolled within 56 days of amenorrhea. A single dose of 200 mg of mifepristone (RU 486) was given and, 48 hr later, prostaglandin was administered as either 5 mg of 9-methylene PGE₂ vaginal gel, meteneprost (classified as group I) or 600 g of oral PGE₁ derivative misoprostol (classified as group II). In group I, 50 subjects and in group II, 51 subjects were treated with the respective schedule. The success rate with mifepristone + misoprostol (group II) was 88.63% which was significantly higher than that with mifepristone + meteneprost (group I) which was 82% (p<0.05). The average duration of bleeding in cases with complete abortion was 8.95±5.67 and 9.77±6.51 in group I and II, respectively. There were no serious side-effects. Only one subject in group I (2%) required blood transfusion for heavy bleeding. This study indicated that oral prostaglandin after a low dose of mifepristone (200 mg) could be developed into an effective method to terminate early pregnancy. Oral administration of both drugs would be a more convenient, feasible, private and acceptable regimen.