Cognitive impairment in asymptomatic carotid artery stenosis is associated with abnormal segments in the Circle of Willis

OBJECTIVE

Our group has previously demonstrated that patients with asymptomatic carotid artery stenosis (ACAS) demonstrate cognitive impairment. One proposed mechanism for cognitive impairment in patients with ACAS is cerebral hypoperfusion due to flow-restriction. We tested whether the combination of a high-grade carotid stenosis and inadequate cross-collateralization in the Circle of Willis (CoW) resulted in worsened cognitive impairment.

METHODS

Twenty-four patients with high-grade (≥70% diameter-reducing) ACAS underwent carotid duplex ultrasound, cognitive assessment, and 3D time-of-flight magnetic resonance angiography (MRA). The cognitive battery consisted of nine neuropsychological tests assessing four cognitive domains: learning and recall, attention and working memory, motor and processing speed, and executive function. Raw cognitive scores were converted into standardized T-scores. A structured interpretation of the MRA images was performed with each segment of the CoW categorized as being either normal or abnormal. Abnormal segments of the CoW were defined as segments characterized as narrowed or occluded due to congenital aplasia or hypoplasia, or acquired atherosclerotic stenosis or occlusion. Linear regression was used to estimate the association between the number of abnormal segments in the CoW, and individual cognitive domain scores. Significance was set to p<0.05.

RESULTS

The mean age of the patients was 66.1 + 9.6 (mean + SD) years and 79.2% (n=19) were male. A significant negative association was found between the number of abnormal segments in the CoW and cognitive scores in the learning and recall (β = -6.5, p = 0.01), and attention and working memory (β = -7.0, p = 0.02) domains. There was a trend suggesting a negative association in the motor and processing speed (β = -2.4, p = 0.35) and executive function (β = -4.5, p = 0.06) domains that did not reach significance.

CONCLUSION

In patients with high-grade ACAS, the concomitant presence of increasing occlusive disease in the CoW correlates with worse cognitive function. This association was significant in the learning and recall and attention and working memory domains. While motor and processing speed and executive function also declined numerically with increasing abnormal segments in the CoW, the relationship was not significant. Since flow restriction at a carotid stenosis compounded by inadequate collateral compensation across a diseased CoW worsens cerebral perfusion, our findings support the hypothesis that cerebral hypoperfusion underlies the observed cognitive impairment in patients with ACAS.

Impact of COVID-19 on heart failure hospitalization and outcome in India - A cardiological society of India study (CSI-HF in COVID 19 times study - "The COVID C-HF study")

OBJECTIVES

The presentation and outcomes of acute decompensated heart failure (ADHF) during COVID times (June 2020 to Dec 2020) were compared with the historical control during the same period in 2019.

METHODS

Data of 4806 consecutive patients of acute HF admitted in 22 centres in the country were collected during this period. The admission patterns, aetiology, outcomes, prescription of guideline-directed medical therapy (GDMT) and interventions were analysed in this retrospective study.

RESULTS

Admissions for acute heart failure during the pandemic period in 2020 decreased by 20% compared to the corresponding six-month period in 2019, with numbers dropping from 2675 to 2131. However, no difference in the epidemiology was seen. The mean age of presentation in 2019 was 61.75 (±13.7) years, and 59.97 (±14.6) years in 2020. There was a significant decrease in the mean age of presentation (p = 0.001). Also. the proportion of male patients decreased significantly from 68.67% to 65.84% (p = 0.037). The in-hospital mortality for acute heart failure did not differ significantly between 2019 and 2020 (4.19% and 4.,97%) respectively (p = 0.19). The proportion of patients with HFrEF did not change in 2020 compared to 2019 (76.82% vs 75.74%, respectively). The average duration of hospital stay was 6.5 days.

CONCLUSION

The outcomes of ADHF patients admitted during the Covid pandemic did not differ significantly. The length of hospital stay remained the same. The study highlighted the sub-optimal use of GDMT, though slightly improving over the last few years.

A qualitative study of the processes by which carers of people with dementia derive meaning from caring

BACKGROUND

Most individuals with dementia live in the community, receiving care from family or lay carers. Carers' wellbeing, and the quality of the care they provide, partly depends on their ability to derive meaning from caring for someone with dementia. Both carers' previous relationship with their relative and the caregiving process itself contribute to this sense of meaning. However, it remains unclear why some carers derive meaning from these sources, whereas others do not.

OBJECTIVE

To further explore the processes by which carers derive a sense of meaning from caring.

METHODS

Representative case sampling was used to recruit a purposive sample of 20 carers for individuals living with dementia. In-depth semi-structured interviews were audio-recorded and transcribed, and analysed using pluralist qualitative methodology.

RESULTS

A framework of three sources from which carers derived meaning from caring was identified, encompassing: carers' perceptions of how 'right' or 'symmetrical' caring felt in light of their current and previous relationship with the person with dementia; maintenance of a 'protected' sense of self within the care relationship; and carers' perceptions of their 'social connectedness' outside the relationships.

CONCLUSION

Holistic assessment based on this framework could help to tailor individualised provision of support, foster resilience and safeguard carers' well-being.

Lung ultrasound evaluation of diabetic patients with acute onset dyspnea and its relationship with established markers of heart failure

OBJECTIVE

The aim of the study was to assess the interrelation between sonographic pleural B-Line, left ventricular function and Naturetic Peptides in type 2 Diabetics with acute onset class III-IV dyspnea. There is dearth of data in this subset of patients in Asian population.

METHODS

Subjects (n=73) were divided into those with pleural B line (Group A, n=41) and those without (Group B) and their serum B type Naturetic Peptide (BNP) and Echocardiography evaluated.

RESULTS

The serum BNP was significantly higher and mean Left Ventricular Ejection Fraction (LVEF) lower in Group A compared to Group B (p<0.001). There was a significant negative correlation between LVEF and BNP and positive correlation between E/E' and BNP. Among patients with LVEF 40% and above (n=36), patients with B line had significantly higher BNP and E/E' compared to those without. Group A had significantly more patients on insulin therapy and troponin positivity than Group B (p<0.01). On auscultation though crepitations was found more frequently in group A but it was present in only 50% of the subset.

CONCLUSION

Pleural B-Lines, LVEF and mitral inflow E/septal E' can be used to rule in heart failure in the above population.

β-T594M epithelial sodium channel gene polymorphism and essential hypertension in individuals of Indo-Aryan ancestry in Northern India

BACKGROUND

The T594M variant of the β-subunit of the sodium epithelial channel (ENaC) gene may contribute to hypertension in individuals of Indo-Aryan origin.

METHODS

Present study was performed to assess the role of the ENaC gene variant as an independent risk factor for hypertension in subjects of Indo-Aryan ancestry. A total of 150 patients of recently detected essential hypertension and 150 matched controls were genotyped for the T594M polymorphism of the ENaC gene by PCR-RFLP method.

RESULTS

β-T594M mutation was found to be non-polymorphic. There was major genotype call in both the groups i.e. cases and controls. Other phenotypic parameters like age, sex and body mass index were also similar among hypertensive patients and controls (P > 0.05). Hypertensive patients had significantly higher total cholesterol and triglycerides compared with controls (P < 0.0001).

CONCLUSION

These results do not suggest an important role for the T594M variant of the ENaC gene contributing to either the development or severity of hypertension in subjects of Indo-Aryan ancestry.

Flavonol isolated from ethanolic leaf extract of Thuja occidentalis arrests the cell cycle at G2-M and induces ROS-independent apoptosis in A549 cells, targeting nuclear DNA

OBJECTIVES

The K-ras gene mutation commonly found in lung adenocarcinomas contributes to their non-invasive expansion. Our main objective here was to develop a chemopreventive agent against K-ras-mutated lung adenocarcinoma cell line like-A549.

MATERIALS AND METHODS

We isolated flavonol from ethanolic leaf extract of Thuja occidentalis, and evaluated its apoptotic potentials on A549 cells. They were treated with 1-10 μg/ml of flavonol and viability was tested retaining normal lung cells L-132 as control. We performed assays such as TUNEL, annexin V, cell-cycle and mitochondrial membrane potentials, by FACS analysis. ROS-mediated oxidative stress and drug-DNA interactions were analysed along with gene expression studies for p53, Bax-Bcl2, cytochrome c, the caspase cascade genes and PARP.

RESULTS

Flavonol reduced A549 cell viability in a dose- and time-dependent manner (IC50 value = 7.6 ± 0.05 μg/ml following 48 h incubation) sparing normal L-132 cells. It effected G2-M phase cell cycle arrest and apoptosis, as indicated by progressive increase in the sub-G1, annexin V and TUNEL-positive cell populations. Apoptotic effects appeared to be mitochondria-dependent, caspase-3-mediated, but ROS-independent. Analysis of circular dichroism data revealed that flavonol intercalated with nuclear DNA. In vivo studies on non small cell lung carcinoma (NSCLC)-induced mice confirmed anti-cancer potential of flavonol.

CONCLUSION

Flavonol-induced apoptosis apparently resulted from intercalation of cells' nuclear DNA. Flavonol inhibited growth of induced lung tumours in the mice, indicating its potential as an effective agent against NSCLC.

Green Synthesis of Fe and Fe/Pd Bimetallic Nanoparticles in Membranes for Reductive Degradation of Chlorinated Organics

Membranes containing reactive nanoparticles (Fe and Fe/Pd) immobilized in a polymer film (polyacrylic acid, PAA-coated polyvinylidene fluoride, PVDF membrane) are prepared by a new method. In the present work a biodegradable, non-toxic -"green" reducing agent, green tea extract was used for nanoparticle (NP) synthesis, instead of the well-known sodium borohydride. Green tea extract contains a number of polyphenols that can act as both chelating/reducing and capping agents for the nanoparticles. Therefore, the particles are protected from oxidation and aggregation, which increases their stability and longevity. The membrane supported NPs were successfully used for the degradation of a common and highly important pollutant, trichloroethylene (TCE). The rate of TCE degradation was found to increase linearly with the amount of Fe immobilized on the membrane, the surface normalized rate constant (k(SA)) being 0.005 L/m(2)h. The addition of a second catalytic metal, Pd, to form bimetallic Fe/Pd increased the k(SA) value to 0.008 L/m(2)h. For comparison purposes, Fe and Fe/Pd nanoparticles were synthesized in membranes using sodium borohydride as a reducing agent. Although the initial k(SA) values for this case (for Fe) are one order of magnitude higher than the tea extract synthesized NPs, the rapid oxidation reduced their reactivity to less than 20 % within 4 cycles. For the green tea extract NPs, the initial reactivity in the membrane domain was preserved even after 3 months of repeated use. The reactivity of TCE was verified with "real" water system.

Feasibility study of a smart pen for autonomous detection of concentration lapses during reading

We implemented a portable smart pen system capable of detecting lapses in concentration during reading. An accelerometer and a microcontroller are embedded within a pen casing to record data as a user reads sections of text using the pen as a pointer. When a substantial pause in reading is detected, the system generates an appropriate warning or alarm. An accompanying software program can communicate with the pen through a USB interface to customize system parameters, record relevant data, and graph collected data over time. The overall effectiveness of a prototype system was tested on 11 normal volunteers and 3 persons with attention deficit disorder (ADD). The prototype system had probability of false alarm of 19%, and sensitivity of 82%. With further refinement, this system could enable patients with attention deficit/hyperactivity disorder maintain concentration during reading in a variety of environments.

An uncommon cause of scleroderma

The human immunodeficiency virus (HIV) pandemic is nearly 20 years old. HIV infection is characterized by profound immunodeficiency resulting in an increased incidence of opportunistic infections and neoplasms. However, the greatest paradox is the occurrence of certain autoimmune disorders in the setting of HIV. These include diffuse interstitial lymphocytosis syndrome (DILS), reactive arthritis, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA). It has also been seen that even in the absence of these well-defined diseases, various rheumatological manifestations such as arthralgias, arthritis, myopathy, vasculitis, and sicca syndrome are commonly associated with HIV. To the best of our knowledge, the association of HIV with scleroderma has not previously been reported.

Endothelial nitric oxide synthase gene haplotypes and circulating nitric oxide levels significantly associate with risk of essential hypertension

Nitric oxide (NO), a potent vasodilator, plays a pivotal role in blood pressure regulation. Endothelial NO synthase gene (NOS3) polymorphisms influence NO levels. Here, we investigated the role of the -922A/G, -786T/C, 4b/4a, and 894G/T polymorphisms of the NOS3 and NO(x) levels in 800 consecutive unrelated subjects comprising 455 patients of essential hypertension and 345 controls. The polymorphisms were investigated independently and as haplotypes. Plasma NO(x) levels (nitrate and nitrite) were estimated by the Griess method. Genotype frequencies for the -786T/C, 4b/4a, and 894G/T polymorphisms differed significantly (P<0.001) between patients and controls and were associated with an increased risk of hypertension (OR=2.0, OR=3.8, OR=1.6, respectively). The 4-locus haplotypes ATaG (H1), ATaT (H2), and GCaG (H3) were significantly associated with essential hypertension and served as susceptible haplotypes (P<or=0.0001). On the other hand, haplotypes ATbG (H4) and GTbG (H5) were negatively associated with hypertension and served as protective haplotypes (P<0.0001). NO(x) levels were significantly lower in patients than controls (P<0.0001). The individual polymorphisms showed marginal association with NO(x) level; however, the susceptible haplotype H2 associated significantly with lower NO(x) levels in patients (P<0.001) and conversely the haplotype H4 with higher NO(x) levels in controls (P<0.001). In conclusion, the 4b/4a and likely -786T/C polymorphisms were identified as the determinants modifying the risk of hypertension. This study identifies the NOS3 variants and haplotypes as genetic risk factors and as useful markers of increased susceptibility to the risk of essential hypertension.

Acute demyelinating encephalitis after jequirity pea ingestion (Abrus precatorius)

INTRODUCTION

Castor and jequirity beans are uncommon causes of poisoning. The more common but less severe castor poisoning is well described, but jequirity bean (Abrus Precatorius) poisoning is rare. The toxicity is attributed to toxalbumins (ricin and abrin) that act by inhibiting protein synthesis. Their use as agents of biological warfare, mechanisms of action, and clinical features of poisoning are summarized.

CASE REPORT

A 30-year-old previously healthy female presented with bloody diarrhea and deep coma following ingestion of 3-4 seeds of a plant called 'ratti.' Investigations, including an MRI brain scan, showed evidence of acute demyelinating encephalitis. The patient died three days later due to progressive central nervous system depression.

DISCUSSION

This is a previously unreported manifestation of jequirity bean poisoning. Demyelination is immune-mediated, and Abrus is a well-known immuno-modulator and stimulator. A possible immunological pathogenic mechanism is hypothesized.

Ultrasonic imaging of myocardial vibrations associated with coronary artery disease

Coronary artery disease (CAD) is a major cause of mortality in the western world. Although progress has been made in recent years for the noninvasive diagnosis of CAD, a widely available, inexpensive and effective diagnostic solution remains elusive. We have developed a novel ultrasound-based technology to detect and analyze the myocardial vibrations associated with diastolic murmurs produced by CAD. Conventional ultrasound imaging systems suppress these vibrations. We have developed algorithms to process the raw ultrasound data and isolate these vibrations and integrated them into a programmable ultrasound system for real-time vibration imaging. In preliminary results from clinical studies of patients with CAD, we have observed localized areas of vibrations in the neighborhood of the stenosed coronary artery. The vibrations are narrowband with frequency >200 Hz, and appear to have harmonic components, thus indicating reasonance phenomena potentially with nonlinear mechanisms involved. No such vibrations were observed in normal subjects. Analysis of myocardial vibrations could provide a noninvasive diagnostic test for CAD that overcomes many of the limitations of conventional noninvasive tests. Potentially, this technology could provide a new way of evaluating CAD and cardiac function.

Ultrasonic imaging of myocardial vibrations associated with coronary artery disease

Coronary artery disease (CAD) is a major cause of majority in the western world. Although progress has been made in recent years for the noninvasive diagnosis of CAD, a widely available, inexpensive and effective diagnostic solution remains elusive. We have developed a novel ultrasound-based technology to detect and analyze the myocardial vibrations associated with diastolic murmurs produced by CAD. Conventional ultrasound imaging systems suppress these vibrations. We have developed algorithms to process the raw ultrasound data and isolate these vibrations and integrated them into a programmable ultrasound system for real-time vibration imaging. In preliminary results from clinical studies of patients with CAD, we have observed localized areas of vibrations in the neighborhood of the stenosed coronary artery. The vibrations are narrowband with frequency >200 Hz, and appear to have harmonic components, thus indicating resonance phenomena potentially with nonlinear mechanisms involved. No such vibrations were observed in normal subjects. Analysis of myocardial vibrations could provide a noninvasive diagnostic test for CAD that overcomes many of the limitations of conventional noninvasive tests. Potentially, this technology could provide a new way of evaluating CAD and cardiac function.

Ultrasonic techniques for assessing wall vibrations in stenosed arteries

Arterial stenoses are often associated with audible bruits. Quantitative analysis of the bruit spectrum has been successfully used to predict the residual lumen diameter in carotid stenoses. Arterial wall vibrations occurring due to turbulent pressure fluctuations in the post-stenotic jet are known to be the source of the bruits. We present novel signal processing techniques that enable the detailed noninvasive assessment of these vibrations in real time using color-Doppler and pulsed-wave Doppler ultrasound. A color-Doppler-based two-dimensional vibration imaging technique can be used to locate the source of the bruits relative to the underlying anatomy. Subsequently, a pulsed-wave Doppler-based technique can be used to analyze the bruit spectrum quantitatively. Experiments in ex vivo arteries indicate that these techniques can predict the location of the bruit as well as its spectral content. Case studies on human subjects with stenosed vein grafts are presented and the clinical applicability of this technique is discussed.

Ataxia and deafness in a young male: An unusual aetiology

We report here a case of 18 year old male with tremors of hands, deafness, tendency to fall while walking, drowsiness and double vision of total duration 1(1/2) years. He had internuclear ophthalmoplegia, broken saccades, hypertonia and hyperreflexia of all four limbs, intention tremors, signs of gait and limb ataxia. Pupillary reactions and fundus examination were normal and signs of meningeal irritation or sensory neurological deficit were absent. MRI head and cervical spine with gadolinium enhancement revealed demyelination as evident from multiple oblong foci isointense on T1-weighted images and hyperintense on T2-weighted and fluid attenuated inversion recovery sequences in corpus callosum, sub-cortical white matter, right thalamus, pons and periaqueductal region of midbrain. Ill-defined linear hyperintense signals were observed in cervical spinal cord. No skeletal abnormality was noted in the skull or cervical spine. Oligoclonal bands were present in the cerebrospinal fluid. Brainstem auditory evoked potentials were abnormal, although visual evoked potentials were in normal range. A diagnosis of primary progressive multiple sclerosis (PPMS) was made fulfilling the revised criteria as laid down. In view of its presentation, it is a unique case of PPMS from India.

Successful pregnancy in untreated limited Wegener's granulomatosis

A thirty four year old female presented with upper and lower respiratory symptoms in the third trimester of pregnancy. After the delivery of a healthy baby, the symptoms progressed to involve multiple organ systems and eventually a diagnosis of limited Wegener's Granulomatosis (Carrington-Liebow syndrome) was made. The extremely rare combination of WG and pregnancy, especially the onset of disease in late pregnancy is discussed. The successful outcome of pregnancy even without treatment of WG is the highlight of the case.

Candidemia--an under-recognized nosocomial infection in Indian hospitals

OBJECTIVE

To study the occurrence of candidemia as a nosocomial infection in a large Indian teaching hospital and to evaluate the predisposing factors for development of such infections.

METHODS

One hundred and one hospitalized patients that developed signs and symptoms of nosocomial bloodstream infections were screened for candidemia and were analyzed for the various predisposing factors like the age of the patient, the duration of hospitalization before the development of fever, neutropenia, use of chemotherapeutic agents, central venous catheters, broad spectrum antibiotics, infection with HIV, diabetes mellitus, use of corticosteroids, administration of total parenteral nutrition, haemodialysis, use of mechanical ventilation, hematological or other malignancies, underlying disease, and any surgical procedure performed on the patient. Candidemic patients were followed up for outcome and the effect of nosocomial candidemia on mortality was assessed and analyzed statistically.

RESULTS

Out of the 101 patients, seven patients had candidemia, an incidence in study population of 6.9%. Three (42.8%) were infected with albicans and the rest with non-albicans candidemia. All the patients with candidemia were admitted in the Intensive Care Units. Amongst the risk factors, the length of hospitalization (p = 0.018), broad-spectrum antibiotics (p = 0.045), central venous catheters (p = 0.005), mechanical ventilation (p = 0.0139) and total parenteral nutrition (p = 0.001) were found to be significantly related to acquisition of nosocomial candidemia. Mortality in the candidemic patients was influenced only by the age of the patients (p = 0.001). Although the mortality amongst the candidemic patients was twice as much as that of the patients not having this infection, still the difference did not reach significance (p = 0.117).

CONCLUSION

Candidemia is an important problem in Indian hospitals. Diagnostic delays could be shortened by more active screening for candidemia especially in the intensive care settings. The rising incidence of non-albicans candidemia in the United States probably is true here as well. There should be a concerted effort to control known risk factors especially in intensive care units.

Psoriatic nephropathy--does an entity exist?

Psoriasis is an immune-mediated chronic inflammatory disorder of the skin. Association with kidney disease has been debated for a long time. Secondary renal amyloidosis in psoriatic arthropathy and drug-induced renal lesions secondary to methotrexate or cyclosporine are accepted accompaniments of psoriasis. IgA nephropathy is also known to occur in psoriatics. We report three interesting cases of renal involvement in long-standing established psoriasis on topical therapy alone. The patients presented with hypertension, significant proteinuria, hypoalbuminemia, and dyslipidemia. Kidney biopsies revealed "mesangioproliferative glomerulonephritis with IgA nephropathy," "focal proliferative glomerulonephritis," and "membranous glomerulonephropathy." The former two had marked active urinary sediment. Patients improved on prednisolone and angiotensin-converting enzyme inhibitors. Contrary to the belief that renal involvement in psoriasis is coincidental, we propose that kidney disease may be a common accompaniment of psoriasis, which may be labeled as "psoriatic nephropathy" or "psoriatic kidney disease." The exact mechanism of this entity is yet to be elucidated.

Purification and characterization of an extracellular agglutinin from Tricophyton rubrum with specificity towards sialic acid containing glycoconjugates

An agglutinin, a monomeric glycoprotein with a molecular mass of about 6.5 kDa and containing 18% sugar has been purified to an apparent homogeneity from a 21 days old culture filtrate of an anthropophilic dermatophyte Tricophyton rubrum. It is a human blood group non-specific agglutinin which also agglutinates animal erythrocytes and Ehrlich ascites carcinoma and Sarcoma-180 cells. It is thermally stable and exhibits maximum activity at pH 8. Amino acid analysis shows a significant amount of glycine, with no cysteine. Glycoproteins inhibited the hemagglutination of the agglutinin, but not the simple sugars, including sialic acid. Fetuin is the most potent inhibitor among the glycoproteins tested. This inhibition gives a hint to binding with Galbeta1-3GalNAc or Galbeta1-4GlcNAc residue containing sialic acid at the terminal position with alpha 2-6 or alpha 2-3 linkage.

Senile onset Tourette's syndrome

Gilles de la Tourette's syndrome (named after a French neurologist) is a relatively rare neuropsychiatric disorder of childhood that presents with fluctuating vocal and motor tics.

Diogenes syndrome: a case report

A rare syndrome, variously known as Diogenes syndrome (Clarke et al, 1975), senile breakdown (MacMillan and Shaw, 1966) and senile squalor, ischaracterized by extreme self-neglect, domestic squalor, social withdrawal, apathy, tendency to hoard rubbish and a blissful unconcern about one's living condition. It is periodically encountered among the elderly, and debate continues regarding the exact cause of the condition. A typical case with severe frontal lobe atrophy is presented.

Combined chlorpromazine and electroconvulsive therapy in mania

We report the efficacy of combined chlorpromazine and electroconvulsive therapy (ECT) in the treatment of mania. Two groups of 15 manic patients received eight ECT sessions either actual or simulated, in a double-blind, controlled study. All patients also received 600 mg of chlorpromazine daily until the sixth session. Results indicate that the group receiving the combination of chlorpromazine and ECT did significantly better than the other group.

Carisoprodol abuse: a report from India

Carisoprodol, a centrally acting muscle relaxant, has recently been noticed to be abused. A series of 16 cases with carisoprodol abuse or dependence is described. Carisoprodol was started by the majority of patients as a substitute for opiates, although its independent distinct effects, similar to the features of hypomania, were recognized and described by most users. The drug is currently available freely over the counter and is a much cheaper substitute for the legally prohibited "harder" drugs. Unless awareness spreads and cautionary measures are taken, carisoprodol abuse might become a great menace in the near future.

Effects of chemical reagents on the allergenicity of house dust

Con A-Sepharose bound and unbound house dust allergens were treated with various protein modifying reagents in order to ascertain the amino acid residues responsible for their allergenicity. Modification of carboxy group and arginine residue of bound fraction led to 90 and 85% loss of allergenicity whereas carboxy group, lysine and tryptophan modified unbound allergen reduced greater than or equal to 85% of activity. Allergenicity of both fractions was highly affected by pronase. On periodate treatment the bound fraction lost its allergenicity more compared to unbound one. Chemical regents had no remarkable effect on the activity of unbound fraction.

Clostridium difficile and its cytotoxin in hospitalized children with acute diarrhea

A total of 498 children, aged 0-14 years, admitted at the B.C. Roy Memorial Hospital for Children, Calcutta, were investigated for the occurrence of Clostridium difficile and its cytotoxin. Of the children in the investigation, 369 suffered from acute diarrhea. Only 8.4% of these children had C. difficile in fecal samples and in vitro cytotoxin was demonstrated in 7%. In 27 (7.3%) of the patients with acute diarrhea C. difficile was isolated as the only pathogen. In contrast, among 129 control children not suffering from acute diarrhea, only 4 (3.1%) harboured C. difficile. Isolation of C. difficile was significantly higher in children under one year of age. None of these patients had any history of prior antibiotic therapy.

Studies on the effect of various parameters on crotalarin-fetuin interaction

With a view to optimise the interaction of crotalarin, a blood group A-specific lectin from the seeds of Crotalaria striata with fetuin the effect of various parameters on the reaction has been studied turbidimetrically. The formation of crotalarin-fetuin complex was dependent on time, temperature, pH and the ionic strength of the medium. The maximum turbidity appeared in 30 min at 20 degrees C and the pH optimum was 3.5. The binding constant (Ka) for crotalarin-fetuin interaction was 5.58 x 10(4) M-1 (pH 3.5) at 20 degrees C. Among the different inorganic salts tested, the cations with increasing concentrations had pronounced effect on binding. KCNS and KI, however, were noninhibitory. The turbidity slightly increased in presence of different sodium salts, whereas periodate and urea reduced the interaction. The different alcohols had no remarkable effect on the above reaction.

Chemical modification studies on a blood group A-specific lectin, crotalarin (Crotalaria striata) and its effect on hemagglutinating activity

Crotalarin, the N-acetyl-D-galactosamine-binding blood group A-specific lectin from the seeds of Crotalaria striata was subjected to various chemical modifications in order to ascertain the amino acid residues responsible for its carbohydrate-binding property. Modification of lysine, cysteine and arginine residues did not affect the carbohydrate-binding activity of the lectin. However, modification of tyrosine residue and carboxy group of the acidic amino acids led to a complete loss of its activity, indicating the involvement of tyrosine and aspartic and glutamic acid in the saccharide-binding respectively. The hemagglutinating activity of the lectin was completely/almost completely lost by modification of tryptophan residues. The relative loss in hemagglutinating activity on modification of tryptophan residues indicate that one residue/molecule is required for the carbohydrate-binding activity of the lectin. Modification was not effective in the presence of D-galactose (0.2 M). A marked decrease in the fluorescence emission was found as the tryptophan residues of crotalarin were modified. The c.d. spectra showed the presence of an identical pattern of conformation in the native and modified lectins which confirms that the loss in activity was due to modification only. The effect of periodate oxidation on crotalarin showed loss of activity whereas action of enzymes retained most of the activity.