Molecular markers for resistance against infectious diseases of economic importance

Huge livestock population of India is under threat by a large number of endemic infectious (bacterial, viral, and parasitic) diseases. These diseases are associated with high rates of morbidity and mortality, particularly in exotic and crossbred cattle. Beside morbidity and mortality, economic losses by these diseases occur through reduced fertility, production losses, etc. Some of the major infectious diseases which have great economic impact on Indian dairy industries are tuberculosis (TB), Johne's disease (JD), mastitis, tick and tick-borne diseases (TTBDs), foot and mouth disease, etc. The development of effective strategies for the assessment and control of infectious diseases requires a better understanding of pathogen biology, host immune response, and diseases pathogenesis as well as the identification of the associated biomarkers. Indigenous cattle (Bos indicus) are reported to be comparatively less affected than exotic and crossbred cattle. However, genetic basis of resistance in indigenous cattle is not well documented. The association studies of few of the genes associated with various diseases, namely, solute carrier family 11 member 1, Toll-like receptors 1, with TB; Caspase associated recruitment domain 15, SP110 with JD; CACNA2D1, CD14 with mastitis and interferon gamma, BoLA--DRB3.2 alleles with TTBDs, etc., are presented. Breeding for genetic resistance is one of the promising ways to control the infectious diseases. High host resistance is the most important method for controlling such diseases, but till today no breed is total immune. Therefore, work may be undertaken under the hypothesis that the different susceptibility to these diseases are exhibited by indigenous and crossbred cattle is due to breed-specific differences in the dealing of infected cells with other immune cells, which ultimately influence the immune response responded against infections. Achieving maximum resistance to these diseases is the ultimate goal, is technically possible to achieve, and is permanent. Progress could be enhanced through introgression of resistance genes to breeds with low resistance. The quest for knowledge of the genetic basis for infectious diseases in indigenous livestock is strongly warranted.

Restriction site detection in repetitive nuclear DNA sequences of Trypanosoma evansi for strain differentiation among different isolates

The differences or similarities among different isolates of Trypanosoma evansi through endonuclease profile was identified in the present study. The repetitive nuclear DNA of T. evansi isolated from infected cattle, buffalo and equine blood was initially amplified by PCR using specific primers. A panel of restriction enzymes, EcoRI, Eco91l, HindIII and PstI were for complete digestion of PCR products. Agarose gel electrophoresis of digested product did not show cleavage fragments and only single DNA band of the original size was visible in the ethidium bromide stained agarose gel. This indicated that the 227 bp PCR product from repetitive sequence had no site-specific cleavage sites for the REs used in this study. No heterogeneity in the repetitive nuclear DNA restriction endonuclease profile among the different isolates was recorded.

Security risk assessment: applying the concepts of fuzzy logic

Chemical process industries (CPI) handling hazardous chemicals in bulk can be attractive targets for deliberate adversarial actions by terrorists, criminals and disgruntled employees. It is therefore imperative to have comprehensive security risk management programme including effective security risk assessment techniques. In an earlier work, it has been shown that security risk assessment can be done by conducting threat and vulnerability analysis or by developing Security Risk Factor Table (SRFT). HAZOP type vulnerability assessment sheets can be developed that are scenario based. In SRFT model, important security risk bearing factors such as location, ownership, visibility, inventory, etc., have been used. In this paper, the earlier developed SRFT model has been modified using the concepts of fuzzy logic. In the modified SRFT model, two linguistic fuzzy scales (three-point and four-point) are devised based on trapezoidal fuzzy numbers. Human subjectivity of different experts associated with previous SRFT model is tackled by mapping their scores to the newly devised fuzzy scale. Finally, the fuzzy score thus obtained is defuzzyfied to get the results. A test case of a refinery is used to explain the method and compared with the earlier work.

Gene frequencies in natural and laboratory populations of Drosophila nasuta

Gene arrangement frequencies of different chromosome types of three inversions, IIL-2, III-35 and III-2 are reported in some natural and laboratory populations of Drosophila nasuta. In general, the frequencies of inversion heterozygotes for these inversions are in excess of what is expected under Hardy-Weinberg equilibrium in both natural and laboratory populations. This suggests that these inversion heterozygotes are heterotic to the species as far as viability is concerned. Similar to what occurs in the cosmopolitan species, chromosomes with standard gene sequences are more frequent than inverted gene sequences in this species. The scarcity of inversion homozygotes is due to reduced viability of their carriers, which probably have lethal or sublethal combinations of alleles in the inverted sections of their chromosomes. Further, the inversion frequencies in laboratory populations follow the frequencies in natural populations.

Land use planning in India

India was the first country to provide for the protection and improvement of environment in its constitution. Land use planning (LUP) or siting of industries has been taken up at the State and Central (Federal) levels over the last few decades. LUP is critical for all types of industries and new residential colonies, but is especially so for the chemical industries. With the experience gained, more coherence in LUP policies is emerging. A few prominent cases of siting of industry, some mixed with public outcry, that have affected the policies are noted in the text. Various factors which affect LUP in India are: population density, infrastructure (roads, power, communication, etc.), level of industrialization in different parts, need for creation of jobs, eco-sensitive regions, tribal regions, historical monuments, etc. This paper discusses the current scene in India and the near future aspects.

Use of failure rate databases and process safety performance measurements to improve process safety

Employing equipment reliability databases can generate a process of continual improvement. This paper suggests a methodology that uses equipment reliability databases, and a process of benchmarking to establish a continual improvement procedure by learning "how others are doing it". A simple decision-making procedure is suggested too, to assist in prioritizing the processes/equipment that are considered to be improved as well as a methodology to measure the improvement.

A simple graphical method for measuring inherent safety

Inherently safer design (ISD) concepts have been with us for over two decades since their elaboration by Kletz [Chem. Ind. 9 (1978) 124]. Interest has really taken off globally since the early nineties after several major mishaps occurred during the eighties (Bhopal, Mexico city, Piper-alfa, Philips Petroleum, to name a few). Academic and industrial research personnel have been actively involved into devising inherently safer ways of production. The regulatory bodies have also shown deep interest since ISD makes the production safer and hence their tasks easier. Research funding has also been forthcoming for new developments as well as for demonstration projects.A natural question that arises is as to how to measure ISD characteristics of a process? Several researchers have worked on this [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Inherent safety in process plant design, Ph.D. Thesis, VTT Publication Number 384, Helsinki University of Technology, Espoo, Finland, 1999; Proceedings of the Mary Kay O'Connor Process Safety Center Symposium, 2001, p. 509]. Many of the proposed methods are very elegant, yet too involved for easy adoption by the industry which is scared of yet another safety analysis regime. In a recent survey [Trans. IChemE, Process Safety Environ. Prog. B 80 (2002) 115], companies desired a rather simple method to measure ISD. Simplification is also an important characteristic of ISD. It is therefore desirable to have a simple ISD measurement procedure. The ISD measurement procedure proposed in this paper can be used to differentiate between two or more processes for the same end product. The salient steps are: Consider each of the important parameters affecting the safety (e.g., temperature, pressure, toxicity, flammability, etc.) and the range of possible values these parameters can have for all the process routes under consideration for an end product. Plot these values for each step in each process route and compare. No addition of values for disparate hazards (temperature, pressure, inventory, toxicity, flammability, etc.) is being suggested to derive an overall ISD index value since that conceals the effects of different parameters. Further, addition of numbers with different units ( degrees C for temperature, atm/bar for pressure, t for inventory, etc.) is inappropriate in scientific sense. The proposed approach has a major advantage of expanding consideration in future to incorporate economic, regulatory, pollution control and worker health aspects, as well as factors such as the experience one has or 'the comfort level' one feels with each of the processes under consideration. Additionally, it would also guide the designers and decision makers into affecting specific changes in the processes to reduce the unsafe features. We demonstrate our simple approach by using the example of six routes to make methyl methacrylate as documented by Edwards and Lawrence [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Quantifying inherent safety of chemical process routes, Ph.D. Thesis, Loughborough University, Loughborough, UK, 1996] and show that the decision could well have been different if addition of disparate hazards had not been done.

A new Hazardous Waste Index

Hazardous wastes, once generated, have to be stored, transported, treated, disposed off, recycled, depending upon the situation. With laws being tightened, all of the above operations have to be done safely without causing harm to people and environment. Before any operation is carried out, it is vital to know the hazardous characteristics of the waste to be handled. Because waste, generally, is a mixture instead of a pure compound, its hazardous characteristics are difficult to determine and generalize because each waste is specific. A new Hazardous Waste Index (HWI) is proposed in this paper. The index measures hazards related to flammability, reactivity, toxicity and corrosivity as well as the pH value for a hazardous waste. Two examples are given for its use. The index can be modified to include radioactive or mixed waste.

Spontaneous expulsion of schwannoma of epiglottis

A rare case of spontaneous expulsion of schwannoma of epiglottis is being reported. These are neurogenic tumours arising from the schwan sheath of peripheral, cranial and sympathetic nerves. The great majority of these neurogenic tumours originate from aryepiglottic fold or false vocal cords. However the neurofibroma of the epiglottis are quite uncommon.

Needle aspiration in large amoebic liver abscess

The role of percutaneous needle aspiration for therapy of uncomplicated, large amoebic liver abscess (ALA) is not defined. Twenty nine patients of ALA with a cavity larger than 5 cm were randomised to two groups: (i) metronidazole 800 mg tid for 10 days combined with needle aspiration (group A, n = 15) and (ii) metronidazole therapy alone (group B, n = 14). Clinical parameters, viz, fever, pain and abdominal tenderness were recorded daily and graded 0 to 3 (in order of increasing severity). A statistically significant benefit was demonstrated in group A for clinical parameters evaluated. Group A patients took less time to become afebrile from the grade 2 level as compared to group B (3.8 +/- 1.7 days and 5.6 +/- 2.2 days respectively; p < 0.05). Reduction in pain intensity and abdominal tenderness from grade 2 to 1 also occurred earlier in group A (0.7 +/- 0.7 days vs 2.9 +/- 0.9 days for pain, P < 0.001 and 1.7 +/- 0.8 days vs 2.9 +/- 1.2 days for abdominal tenderness, p < 0.001). The mean duration of hospitalization was significantly shorter in group A as compared to group B (5.8 +/- 0.8 days vs 7.4 +/- 1.5 days, p < 0.001). Improvement in haematological and biochemical variables was similar in both groups. We conclude that percutaneous therapeutic needle aspiration of uncomplicated, large ALA hastens clinical recovery.

Neuroticism and stressful life events in patients with non-ulcer dyspepsia

Hindi adaptation of the Middlesex Hospital Questionnaire (MHQ), Brief Psychiatric Rating Scale and Presumptive Stressful Life Events Scale were used to measure neuroticism, psychiatric morbidity and stressful life events in 35 patients with non-ulcer dyspepsia (NUD), 22 cass of peptic ulcer disease (PUD), 65 irritable bowel syndrome (IBS) and 45 age and sex matched healthy controls. NUD subjects had significantly higher total MHQ scores (28.8 +/- 11.3; p < 0.001) and scores in subscales of somatization (7.8 +/- 3.4; p < 0.001) and hysterical personality traits (5.5 +/- 2.8; p < 0.01) compared to healthy controls. MHQ scores in IBS subjects was significantly higher than in NUD, but in PUD subjects it was in-between NUD and healthy controls. Psychiatric morbidity, as assessed by Brief Psychiatric Rating Scale, was significantly higher in patients with NUD and IBS than in normal controls. Stressful Life event score was statistically similar in all the groups.

Clinicopathological profile of abdominal tuberculosis

The clinical and histopathological profile is presented of 145 patients with abdominal tuberculosis studied prospectively over a period of 5 years. The study highlights the role of various investigations and therapeutic response in this condition.

Some evidence of incipient speciation in Drosophila kikkawai

Altogether 11 geographic populations of Drosophila kikkawai were analysed from the viewpoint of karyotypic variation, inversion polymorphism and sexual isolation. The results revealed that of all the populations, the New Guinea population was the most genetically diverged, characterized by its distinct karyotype, possession of a fixed inversion, and its females exhibiting sexual isolation at the level of preferential mating. Based on these findings it was inferred that incipient speciation has proceeded in D. kikkawai and its New Guinea population is on its way to speciation.

Salmonella group-E (Senftenberg) lung abscess: a case report

A male patient presented with complaints of fever, cough with expectoration, burning micturition and 5-6 semisolid motions per day for the past 6 days. Skiagram chest (PA view) revealed lung abscess in the left mid zone. There was no improvement, symptomatically and radiologically, after an empirical course of antibiotics (IV ampicillin and gentamycin). Sputum, urine and stool cultures grew salmonella group E organisms sensitive only to cefotaxime. The patient was treated with IV cefotaxime and responded well clinically, radiologically and bacteriologically.

Accumulation of B-chromosomes in drosophila kikkawai Burla

Drosophila kikkawai is a unique species in the genus, having two types of B-chromosomes with distinct centromeres. Laboratory experiments pertaining to their accumulation were carried out, using continuous selection and inbreeding procedures. Karyotypes with B-chromosomes ranged from 1 to 4. A maximum of four B-chromosomes in a culture were accumulated which seems to be the maximum tolerable limit in this species.

Analysis of mitochondrial DNA in two species of the bipectinata species complex of Drosophila

Drosophila bipectinata and D. malerkotliana are members of the bipectinata species complex of the ananassae subgroup in the melanogaster species group of Drosophila. The mtDNA from 18 isofemale strains of these species was analyzed, using 13 restriction endonucleases. Altogether, eight mtDNA haplotypes were detected, of which the haplotype 1B was shared by the two species. Restriction cleavage map of mtDNA of these species was constructed. The net nucleotide substitutions per site calculated between these species was found to be 0.0002. This value appeared to be relatively much lower than expected at the interspecific level, even lower than that reported between two subspecies of Drosophila despite both being good species. This extreme closeness of their mtDNAs is discussed in the light of recent findings.

Combination of anticholinergic agent and H2 receptor antagonist in duodenal ulcer treatment--a randomized, double blind multicenter study

BACKGROUND

The acid suppressive abilities of H2 receptor antagonists and anticholinergics have been claimed to be additive.

METHODS

A multicenter, double-blind, randomized trial comparing ranitidine (150 mg) plus propantheline bromide 15 mg at bedtime to ranitidine 300 mg alone at bedtime was conducted in 161 patients with endoscopically confirmed uncomplicated duodenal ulcer.

RESULTS

After six weeks of therapy, ulcer healing rates in the two groups were comparable ie 80% in the combination group (ranitidine + propantheline) and 79.4% in the ranitidine group. Pain relief after one, two and four weeks of treatment was also comparable in the two groups. Side effects to drugs were minor and comparable in both the groups.

CONCLUSION

A combination of 150 mg ranitidine and 15 mg propantheline bromide is as efficacious as 300 mg ranitidine in inducing healing of uncomplicated duodenal ulcers, with similar side-effects but at greatly reduced cost.

Evaluation of Manning's criteria in the diagnosis of irritable bowel syndrome

Six symptoms of Manning et al are widely used in clinical practice to diagnose irritable bowel syndrome (IBS). We studied 123 patients to evaluate the diagnostic value of Manning's criteria, using a preformed bowel symptom questionnaire which included these six symptoms. This study included 65 patients with IBS, 35 patients with non-ulcer dyspepsia, 23 patients with organic diseases of colon and 45 healthy controls. Sensitivity of presence of three or more symptoms of Manning's criteria discriminating irritable bowel syndrome from all other groups was 66.1%. Manning's criteria discriminated irritable bowel syndrome from organic diseases of colon with specificity and positive predictive value of 66.9% and 82.6%. When irritable bowel syndrome was compared with non-ulcer dyspepsia and healthy controls, specificities of Manning's criteria were 91.4% and 93.3% and positive predictive values 93.4% and 93.4% respectively.

Obstructive jaundice--a diagnostic appraisal

One hundred and eight suspected cases of obstructive jaundice (OJ) were analysed using ultrasonography, percutaneous transhepatic cholangiography (PTC) or Endoscopic retrograde cholangiopancreatography (ERCP) or both. Clinical evaluation had accuracy of 93% in identifying OJ and establishing aetiology in 62%, however, it lacked specificity. Ultrasonography was useful in differentiating obstructive jaundice from medical jaundice in 91% of cases. However, the cause and site of biliary obstruction could be identified in 55% and 46% respectively. PTC was helpful in detecting the site of obstruction in 80.4% and nature in 63% of cases. Its failures were mostly associated with the presence of metastasis in the liver. ERCP successfully attained cholangiography in 58% and pancreatogram in 70% of cases. Overall diagnostic yield of ERCP was 67% in view of additional endoscopic findings in 18 cases. The complications were occasional and could be managed effectively with medical treatment. This study suggests utility of clinical evaluation in OJ inspite of its poor specificity and comparative value of PTC and ERCP in establishing the site as well as nature of lesion.

Endoscopic sphincterotomy: preliminary experience at a university hospital

Endoscopic sphincterotomy (ES) was attempted in 38 patients with biliary calculi. There were 21 patients (55.3%) with common bile duct (CBD) stones following cholecystectomy, 14 patients (36.8%) with intact gall bladder and 3 patients with retained CBD stones along with T tube in the early post-operative period. Endoscopic sphincterotomy was possible in all but one patient and duct clearance was attained in 34 (89.4%) patients. Spontaneous clearance of calculi occurred in 31 (81.6%) patients while 3 patients required instrumental extraction. Four patients failed to clear stones and required surgical intervention. Complications occurred in 4 (10.5%) patients--haemorrhage in two, pancreatitis and cholangitis in one each. One patient died of bleeding on the 4th day following ES while hemostasis was achieved in other after two units of blood. Other complications were managed conservatively without any mortality. Endoscopic sphincterotomy appears to be a simple, effective and safe therapeutic modality for the management of biliary calculi.

Heterosis and the lack of coadaptation in Drosophila nasuta

Natural populations of Drosophila nasuta are polymorphic for several paracentric inversions. Two non-overlapping inversions on the third chromosome (III-2 and III-35) are heterotic in both laboratory and natural populations and display an extreme case of linkage disequilibrium. Intra- and interpopulation crosses involving standard and inverted gene orders of the III-2 and III-35 inversions were made to test if the polygenic complexes within these inversions are coadapted. The inversion heterozygotes formed by the two chromosomes derived from different localities exhibited heterosis since the viability of the heterozygotes was greater than that of either of the two homozygotes. In intrapopulation crosses, the heterozygotes were also heterotic. The present results thus indicated a lack of coadaptation among polygenic complexes within the inversions of D. nasuta. The data suggest that the heterosis produced by these linked inversions is the result of natural selection and epistasis.

Autonomic reflexes in borderline hypertensives

Autonomic reflexes were studied in 53 patients with borderline hypertension (BLH) and 25 normotensives. BLH patients had higher basal heart rate. With 2 minutes of sustained head-up passive tilt of 50 degrees or 75 degrees, the rise in heart rate was comparable in both groups but the rise in blood pressure was significantly more in the BLH group. The rise in systolic pressure with Valsalva manoeuvre as well as with sustained hand grip was significantly higher in BLH patients. The postural tachycardia index and Valsalva index were significantly lower in BLH patients probably due to higher basal heart rate.

Gastro-esophageal reflux disease (GERD): an appraisal of different tests for diagnosis

Fifty symptomatic patients with GERD, 20 each of non ulcer dyspepsia (NUD) & duodenal ulcer (DU) and 10 healthy controls were subjected to various tests employed for diagnosis of GERD. Among these endoscopy and histology had highest sensitivities (92% & 91% respectively) followed by Bernstein's test (overall 88%; early positivity 72%) and oesophagography (70%). The specificities of various tests were: endoscopy (86%), histology (82%) and Bernstein's test (overall 80%; early positive 94%). The false positivity was mainly in DU subjects where majority (greater than 84%) had two or more of these tests offitive. Any two of the three tests (endoscopy, histology & Bernstein's test) in combination had a sensitivity of 80-91% and a specificity of 90-92%. Our observations suggest that these tests, particularly in combination, are useful in establishing the diagnosis of GERD and that subclinical oesophagitis in DU might be responsible for the false positivity of these tests.

Serodiagnosis of gut tuberculosis

The efficacy of enzyme-linked immunosorbent assay (ELISA) in the diagnosis of gut tuberculosis was evaluated. The study included 95 patients with gut tuberculosis, 40 with pulmonary tuberculosis, 25 with non-tubercular intestinal diseases and 40 healthy controls. Mantoux response and antibody titre against PPD using ELISA were studied. The ELISA sensitivity in gut tuberculosis was 80% and in pulmonary tuberculosis 90%. It was also positive in 12% of patients with non-tubercular intestinal diseases and 5% of healthy controls. The sensitivity of Mantoux test in gut (77%) and pulmonary (84%) tuberculosis was comparable to that of ELISA. However, Mantoux test lacked diagnostic significance due to high positivity in non-tubercular disease patients (55%) and healthy controls (56%), whereas ELISA was highly specific (93%) for the diagnosis of gut tuberculosis.

Comparison of stool microscopy and serology (enzyme linked immunosorbent assay) in epidemiology of amebiasis

Stools from 634 individuals from Varanasi were examined for Entamoeba histolytica (EH). Serology was done in these subjects by enzyme linked immunosorbent assay (ELISA) employing filter paper technique. Stools were positive for EH in 16.9%, and serology in 15.9%. Both the tests were positive in only 5.2%. In 72.4% both the tests were negative. In 11.7% of stool positive cases, serology was negative, and in 10.7% with positive serology stool examination did not reveal EH. A majority (92.5%) of stool positive subjects had only cysts. Additional parasites were detected in 15.3%.

Neuroticism in patients with irritable bowel syndrome

Employing a Hindi adaptation of the Middlesex Hospital Questionnaire (MHQ), neuroticism level was assessed in 133 subjects with irritable bowel syndrome and compared with that in patients with organic bowel disease (33), healthy population (140) and known neurotics (110). Compared with healthy controls and patients with organic bowel disease, significantly higher scores were found among irritable bowel syndrome patients in all the subscales except obsession. The total of scores was midway between those of the normal population and known neurotics. Neurotic disorder was detected in 51% of irritable bowel syndrome patients compared to 24% of organic bowel disease subjects (P less than 0.05) and 7.8% of the healthy population. Cut-off points, calculated as mean + 2 SD of scores in the healthy population, were found to be reliable as shown by clinical interview.

Chromosomal polymorphism in Indian populations of Drosophila bipectinata Duda

Drosophila bipectinata, a member of the melanogaster species group, is a common and wide-spread species in the Indian subcontinent. A geographic survey of inversion polymorphism has been carried out in Indian populations. Altogether, nine paracentric inversions are detected in the populations examined during this study. Of the nine inversions, two have been described earlier by Bock from laboratory populations established from Borneo, Thailand and the Philippines. The possible relationship between inversions and different environmental conditions is discussed.

Irritable bowel syndrome: therapeutic evaluation of indigenous drugs

Among 169 patients with irritable bowel syndrome (IBS), standard therapy (with clidinium bromide, chlordiazepoxide and isaphaghulla), a compound Ayurvedic preparation (with Aegle marmelos correa plus Bacopa monniere Linn) along with a matching placebo were given in a double blind randomised trial for 6 wk. The Ayurvedic preparation in 57 patients was found effective in 64.9 per cent, while standard therapy (60 patients) was useful in 78.3 per cent. Patients on placebo (52 patients) showed improvement in 32.7 per cent only. Ayurvedic therapy was particularly beneficial in diarrhoea predominant form as compared to placebo. The standard therapy was more useful in the painful form of IBS as compared to placebo and Ayurvedic preparation. In gas predominant form the effect of standard as well as Ayurvedic therapy, was similar to placebo. Long-term follow-up (greater than 6 months) showed that both forms of therapy were no better than placebo in limiting the relapse.

Efficacy of tinidazole (Fasigyn) in giardiasis by parasitologic, biochemical, and gut transit studies

Twenty patients (18 M, 2 F; age 16-32 yrs) with symptomatic giardiasis were treated with tinidazole: ten each with a dose of 150 mg twice daily for 7 days, and a single dose of 2 g (50 mg/kg). Stool examination by formalin-ether concentration method was carried out before and one month after treatment. Cure was defined as absence of G lamblia in the stools. Fecal fat excretion (100 g load) and D-xylose absorption (5 g load) were measured before treatment and, if abnormal, repeated one month after treatment. Gut transit time was measured before and one month after treatment by giving radio-opaque beads orally and following their progress fluoroscopically to complete elimination. Parasitologically, all 20 patients were cured. Clinically, there was marked to complete relief of symptoms. Concomitantly, there was significant (p less than 0.01) reduction in fecal fat excretion, improvement in D-xylose absorption, and increase in gut transit time.

Medical myotomy for achalasia cardia. Long term results

Pneumatic dilatation was effective in relieving dysphagia in 16/17 subjects with achalasia cardia. It was also effective and safe in those with sigmoid oesophagus, although dilatation persisted in them. Recurrences were noted in one quarter of cases which were managed satisfactorily with subsequent dilatations. There were no complications. Pneumatic dilatation appears very useful in the management of achalasia cardia.

Linkage disequilibrium, natural selection, and epistatic gene interaction in Drosophila nasuta

The data of linkage disequilibrium between III-2 and 111-35 gene arrangements in natural populations of Drosophila nasuta is presented. The results demonstrated that there was significant linkage disequilibrium between the above gene arrangements in natural populations. Among all nine possible karyotypic combinations, only four combinations were seen. The absence of some combinations might be because of sublethal combinations of genes that reduced the viabilities of their carriers. The frequency of double inversion heterozygotes was always in excess and only 1.29% single hetrozygotes were observed. Based on these findings, we suggest that natural selection acting through the suppression of recombination and epistatic gene interaction providing fitness are the main factor for the maintenance of linkage disequilibrium between the above linked gene arrangements in natural populations of D. nasuta.Key words: linkage disequilibrium, selection, epistasis, Drosophila nasuta.

Duodenal tuberculosis

The clinical and radiological features in 30 cases of duodenal tuberculosis are presented. The patients are divisible into two groups on the basis of their presenting features. Twenty-two had symptoms and signs of gastric or duodenal obstruction, and eight patients had dyspepsia suggesting peptic ulceration. In the first group, laporotomy showed that the duodenal obstruction was due to extrinsic compression by matted tuberculous lymph nodes in the majority; there was only five intrinsic strictures. In patients with dyspepsia there were bulbar and post-bulbar ulcers accompanied by more widespread mucosal changes, induration, and periduodenal lymphadenopathy. Bypass procedures were performed to relieve obstruction; no resection was possible because of the adherence of the lymph node masses.