Clinical and dermoscopic characteristics of Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with a high mortality rate. Diagnosis is often delayed.

OBJECTIVES

To characterize the dermoscopic features of MCC.

METHODS

Clinical and dermoscopic images of 12 biopsy-proven MCCs were analysed in a retrospective manner, with existing dermoscopic criteria being scored independently by three dermatologists.

RESULTS

The four most frequent clinical features were cherry red colour, shiny surface, sharp circumscription and nodular morphology. Significant dermoscopic features included linear irregular and polymorphous vessels, poorly focused vessels, milky pink areas, white areas, structureless areas and architectural disorder. Pigmented structures were absent from all lesions.

CONCLUSIONS

The dermoscopic features described herein help the clinician to distinguish MCC from other benign and malignant red nodules. Increasing recognition of the presenting features will facilitate earlier diagnosis of MCC and reduced mortality.

Alzheimer's disease mutations in APP but not γ-secretase modulators affect epsilon-cleavage-dependent AICD production

Pathological amino-acid substitutions in the amyloid precursor protein (APP) and chemical γ-secretase modulators affect the processing of APP by the γ-secretase complex and the production of the amyloid-beta peptide Aβ42, the accumulation of which is considered causative of Alzheimer's disease. Here we demonstrate that mutations in the transmembrane domain of APP causing aggressive early-onset familial Alzheimer's disease affect both γ- and ε-cleavage sites, by raising the Aβ42/40 ratio and inhibiting the production of AICD50-99, one of the two physiological APP intracellular domains (ICDs). This is in sharp contrast to γ-secretase modulators, which shift Aβ42 production towards the shorter Aβ38, but unequivocally spare the ε-site and APP- and Notch-ICDs production. Molecular simulations suggest that familial Alzheimer's disease mutations modulate the flexibility of the APP transmembrane domain and the presentation of its γ-site, modifying at the same time, the solvation of the ε-site.

Identification of antibodies against hydropericardium syndrome in wild birds

1. Domestic fowl and free-living birds were examined for the presence or absence of antibodies against hydropericardium syndrome (HPS) using an indirect haemagglutination assay. 2. Two-hundred and eighty serum samples of commercial (45 broilers, 20 adult layers and 15 Fayoumi fowl) and wild birds, including 65 peafowl, 45 pigeons, 10 crows, 30 house sparrows, 10 doves, 15 ducks, 10 parrots and 15 guinea fowl, were collected and examined. 3. The percentage of HPS-positive serum samples was 80% in house crows, 78% in pigeons, 7% in house sparrows and 6% in peafowl. 4. The sera obtained from parrots, doves, ducks and guinea fowl were all negative. 5. This study suggests that crows and pigeons could be carriers of the HPS agent.

Emerging therapeutics for Alzheimer’s disease

Alzheimer's disease (AD) is the most common form of dementia, with prevalence and the accompanying socioeconomic impact set to increase over the coming decades. Currently available medications result, at best, in modest cognitive improvement. With increasing understanding of the underlying pathology, new therapeutic targets are being identified at an ever-increasing rate. The key pathological events in the AD brain are deposition of insoluble amyloid-beta peptide (Abeta), formation of neurofibrillary tangles and neuroinflammation leading, ultimately, to neuronal cell death. Each of these will be considered, in detail, in terms of the variety of therapeutic approaches currently being investigated and mechanisms that may prove amenable to intervention in the future.

Detection and seroprevalence of foot and mouth disease in sheep and goats in Punjab, Pakistan

Foot and mouth disease (FMD) is a highly contagious disease of ruminants that causes huge economic losses around the globe. However, the prevalence of FMDV in small ruminants has been overlooked in Pakistan. A seroepidemiological study was conducted in Chakwal, Faisalabad and Khanewal districts of Punjab, Pakistan to determine the prevalence of FMD in sheep and goats. A total 1200 serum samples were collected from sheep (n = 180) and goats (n = 920) and were subjected to 3ABC non-structural protein enzyme-linked immunosorbent assay for detection of antibodies against non-structural proteins of FMD virus. Samples collected from clinical cases were also confirmed for FMDV using RT-PCR. The overall seroprevalence of FMD in sheep and goats was 21% (n = 252) while 19.44% (n = 35) in sheep and 21.27% (n = 217) prevalence was recorded in goats. Highest seroprevalence (32.5%) was observed in southern Punjab (Khanewal), followed by (25.75%) central Punjab (Faisalabad) and the lowest seroprevalence (4.75%) was detected in northern Punjab (Chakwal). There was no statistically significant difference in seroprevalence between sheep and goats. Among different risk factors tested, age and sex were found to be significantly associated with the prevalence of disease while pregnancy and herd type had no association with the prevalence of the disease. This study illustrate that FMD is highly prevalent in sheep and goats in Punjab. Therefore, a broader study is needed to ascertain the countrywide prevalence of FMD in small ruminants.

Role of Toll-like receptor 2 (-196 to -174) polymorphism in susceptibility to pulmonary tuberculosis in Pakistani population

Tuberculosis (TB) is a global public health problem and a source of preventable deaths each year, with 8.8 million new cases of TB and 1.6 million deaths worldwide. Pakistan ranks sixth on the list of 22 high-burden tuberculosis countries in the world. The transitions from infection to clinical disease are very few signifying that host-defence factors could lead to the development of active disease. Toll-like receptor (TLR) 2 polymorphisms have been associated with regulation of TLR expression and development of active TB. In this study, blood samples of 187 subjects including 100 healthy and 87 TB positive were collected from three districts of Pakistan. DNA was extracted from blood and TLR 2 (-196 to -174del) polymorphism was analysed by polymerase chain reaction (PCR). The results suggest that the frequency of -196 to -174del/del polymorphism of TLR2 was significantly higher in TB-positive patients compared with healthy. Results revealed that (-196 to -174del) polymorphism may increase the susceptibility to TB in healthy population of Pakistan. Moreover, males with heterozygous genotype (I/D) are more prone to TB than females with the same genotype. The occurrence of TB infection has been found positively associated with the age, suggesting that the population within the range of 21-45 years is more susceptible to Mycobacterium tuberculosis than other age groups studied. A significant association is also observed between smoking and the chances of developing TB, confirming that smoking strongly promotes its incidence.

Substrate determinants in the C99 juxtamembrane domains differentially affect γ-secretase cleavage specificity and modulator pharmacology

The molecular mechanisms governing γ-secretase cleavage specificity are not fully understood. Herein, we demonstrate that extending the transmembrane domain of the amyloid precursor protein-derived C99 substrate in proximity to the cytosolic face strongly influences γ-secretase cleavage specificity. Sequential insertion of leucines or replacement of membrane-anchoring lysines by leucines elevated the production of Aβ42, whilst lowering production of Aβ40. A single insertion or replacement was sufficient to produce this phenotype, suggesting that the helical length distal to the ε-site is a critical determinant of γ-secretase cleavage specificity. Replacing the lysine at the luminal membrane border (K28) with glutamic acid (K28E) increased Aβ37 and reduced Aβ42 production. Maintaining a positive charge with an arginine replacement, however, did not alter cleavage specificity. Using two potent and structurally distinct γ-secretase modulators (GSMs), we elucidated the contribution of K28 to the modulatory mechanism. Surprisingly, whilst lowering the potency of the non-steroidal anti-inflammatory drug-type GSM, the K28E mutation converted a heteroaryl-type GSM to an inverse GSM. This result implies the proximal lysine is critical for the GSM mechanism and pharmacology. This region is likely a major determinant for substrate binding and we speculate that modulation of substrate binding is the fundamental mechanism by which GSMs exert their action.

Focal expression of adeno-associated viral-mutant tau induces widespread impairment in an APP mouse model

Adeno-associated virus serotype 6 (AAV6) viral vectors encoding mutant and normal tau were used to produce focal tau pathology. Two mutant forms of tau were used; the P301S tau mutation is associated with neurofibrillary tangle formation in humans, and the 3PO mutation leads to rapid tau aggregation and is associated with pathogenic phosphorylation and cytotoxicity in vitro. We show that adeno-associated viral injection into entorhinal cortex of normal and tau knockout animals leads to local overexpression of tau, and the presence of human tau in axons projecting to and emanating from the entorhinal cortex. Starting at 2 months and increasing by 6 months post-injection neurons expressing mutant tau developed hyperphosphorylated tau pathology, in addition to dystrophic neurites. There was neuronal loss in tau-expressing regions, which was similar in normal and in TASTPM mice injected with mutant tau. There was neuroinflammation around plaques, and in regions expressing mutant tau. We saw no evidence that mutant tau had affected amyloid-beta pathology or vice versa. Morris water maze behavioral tests demonstrated mild memory impairment attributable to amyloid-beta pathology at 2 and 4 months, with severe impairment at 6 months in animals receiving adeno-associated viral-3PO. Therefore, TASTPM mice injected with mutant tau displayed many of the main features characteristic of human Alzheimer's disease patients and might be used as a model to test new drugs to ameliorate clinical features of Alzheimer's disease.

The role of γ-secretase activating protein (GSAP) and imatinib in the regulation of γ-secretase activity and amyloid-β generation

γ-Secretase is a large enzyme complex comprising presenilin, nicastrin, presenilin enhancer 2, and anterior pharynx-defective 1 that mediates the intramembrane proteolysis of a large number of proteins including amyloid precursor protein and Notch. Recently, a novel γ-secretase activating protein (GSAP) was identified that interacts with γ-secretase and the C-terminal fragment of amyloid precursor protein to selectively increase amyloid-β production. In this study we have further characterized the role of endogenous and exogenous GSAP in the regulation of γ-secretase activity and amyloid-β production in vitro. Knockdown of GSAP expression in N2a cells decreased amyloid-β levels. In contrast, overexpression of GSAP in HEK cells expressing amyloid precursor protein or in N2a cells had no overt effect on amyloid-β generation. Likewise, purified recombinant GSAP had no effect on amyloid-β generation in two distinct in vitro γ-secretase assays. In subsequent cellular studies with imatinib, a kinase inhibitor that reportedly prevents the interaction of GSAP with the C-terminal fragment of amyloid precursor protein, a concentration-dependent decrease in amyloid-β levels was observed. However, no interaction between GSAP and the C-terminal fragment of amyloid precursor protein was evident in co-immunoprecipitation studies. In addition, subchronic administration of imatinib to rats had no effect on brain amyloid-β levels. In summary, these findings suggest the roles of GSAP and imatinib in the regulation of γ-secretase activity and amyloid-β generation are uncertain.

Development and characterization of a novel membrane assay for full-length BACE-1 at pH 6.0

β-Site amyloid precursor protein cleaving enzyme-1 (BACE-1) is a transmembrane aspartic protease that mediates the initial cleavage of the amyloid precursor protein (APP), leading to the generation of amyloid-β (Aβ) peptides that are thought to be causative of Alzheimer's disease (AD). Consequently, inhibition of BACE-1 is an attractive therapeutic approach for the treatment of AD. In general, in vitro biochemical assays to monitor BACE-1 activity have used the extracellular domain of the protein that contains the catalytic active site. This form of BACE-1 is catalytically active at acidic pH and cleaves APP-based peptide substrates at the β-site. However, this form of BACE-1 does not mimic the natural physiology of BACE-1 and shows minimal activity at pH 6.0, which is more representative of the pH within the intracellular compartments where BACE-1 resides. Moreover, high-throughput screens with recombinant BACE-1 at pH 4.5 have failed to identify tractable leads for drug discovery, and hence, BACE-1 inhibitor development has adopted a rational drug design approach. Here we describe the development and validation of a novel membrane assay comprising full-length BACE-1 with measurable activity at pH 6.0, which could be used for the identification of novel inhibitors of BACE-1.

Putative Virulence Genes and Biofilm Production Among Typical Enteroaggregative Escherichia coli Isolates from Diarrhoeic Children in Kashmir and Andhra Pradesh

Fifty-eight typical EAEC isolates from children with diarrhoea were examined for HEp-2 cell adherence assay, presence of dispersin (aap), yersiniabactin (irp2), plasmid encoded toxins (pet), Shigella enterotoxin1 (set1A) and cryptic open reading frame (shf) putative virulence genes by polymerase chain reaction as well as for biofilm production. All the isolates showed aggregative adherence pattern on HEp-2 cells. All but five isolates (91.3 %) carried aap gene. While irp2, pet, set1A and shf genes were detected in 68.9, 5.1, 39.6, and 60.3 % isolates, respectively. Thirty-three (64.7 %) isolates out of 51 tested were found to produce biofilm which was found to be significantly associated only with set1A virulence gene (P = 0.025). Highest amount of biofilm was produced by a strain that possessed all the genes studied. Out of 14 isolates in which the most frequent gene combination (aap, irp2 and shf) was observed, only six produced biofilm. It is concluded that there is significant heterogeneity in putative virulence genes of EAEC isolates from diarrhoeic children and biofilm formation is associated with multiple genes.

Fluoride in the drinking water of Nagaur tehsil of Nagaur District, Rajasthan, India

Fluoride concentration of groundwater samples from 100 villages of Nagaur tehsil was determined, 85 villages were found to have fluoride concentration more than 1.5 mg/L. The maximum fluoride concentration was recorded 6.6 mg/L in groundwater of Singhani village, while the minimum was recorded in Kurchhi village. As per the desirable and maximum permissible limit for fluoride in drinking water, determined by World Health Organization, the groundwater of about 85 villages of the studied sites is unfit for drinking purpose.

Γ-secretase modulators do not induce Aβ-rebound and accumulation of β-C-terminal fragment

γ-secretase inhibitors (GSIs) have been developed to reduce amyloid-β (Aβ) production for the treatment of Alzheimer's disease by inhibiting the cleavage of amyloid precursor protein (APP). However, cross-inhibitory activity on the processing of Notch can cause adverse reactions. To avoid these undesirable effects, γ-secretase modulators (GSMs) are being developed to selectively reduce toxic Aβ production without perturbing Notch signaling. As it is also known that GSIs can cause a paradoxical increase of plasma Aβ over the baseline after a transient reduction (known as Aβ-rebound), we asked if GSMs would cause a similar rebound and what the potential mechanism might be. Our studies were performed with one GSI (LY-450139) and two chemically distinct GSMs. Although LY-450139 caused Aβ-rebound as expected in rat plasma, the two GSMs did not. Inhibition of APP processing by LY-450139 induced an accumulation of γ-secretase substrates, α- and β-C-terminal fragments of APP, but neither GSM caused such an accumulation. In conclusion, we discover that GSMs, unlike GSIs, do not cause Aβ-rebound, possibly because of the lack of accumulation of β-C-terminal fragments. GSMs may be superior to GSIs in the treatment of Alzheimer's disease not only by sparing Notch signaling but also by avoiding Aβ-rebound.

A clinical trial comparing parenteral oxytetracyline and enrofloxacin on time to recovery in sheep lame with acute or chronic footrot in Kashmir, India

BACKGROUND

No clinical trials have been conducted in India on the efficacy of parenteral antibacterials to treat footrot in sheep. In addition, there are no studies worldwide on the efficacy of parenteral antibacterials to treat chronic footrot. Sixty two sheep with acute footrot and 30 sheep with chronic footrot from 7 villages in Kashmir, India were recruited into two separate trials. Sheep with acute footrot were allocated to one of three treatments using stratified random sampling: long acting parenteral oxytetracycline, long acting parenteral enrofloxacin and topical application of potassium permanganate solution (a traditional treatment used by sheep farmers in India). In a quasi pre-post intervention design, sheep with chronic footrot that had not responded to treatment with potassium permanaganate were randomly allocated to treatment with one of the two parenteral antibacterials mentioned above. Sheep with acute footrot were treated on day 0 and those with chronic footrot on days 0, 3, 6 and 9. Sheep were monitored for up to 28 days after treatment. Time to recovery from lameness and initial healing of lesions was assessed using Kaplan-Meier survival curves, nonparametric log-rank and Wilcoxon sign-rank tests.

RESULTS

There was significant correlation in recovery from lameness and presence of healing lesions in sheep with acute (r = 0.94) or chronic (r = 0.98) footrot. Sheep with acute footrot which were treated with parenteral antibacterials had a significantly more rapid recovery from lameness and had healing lesions (median = 7 days) compared with those treated with topical potassium permanganate solution (less than 50% recovered in 28 days). The median time to recovery in sheep with chronic footrot treated with either antibacterial was 17 days; this was significantly lower than the median of 75 days lame before treatment with antibacterials. The median time to recovery for both acute and chronic footrot increased as the severity of lesions increased. There was no difference in time to recovery by age, body condition score, duration lame, or presence of pus in the foot within acute and chronically affected sheep.

CONCLUSIONS

We conclude that use of parenteral antibacterials to treat sheep lame with either acute or chronic footrot in India is highly effective. This is likely to improve welfare and give economic benefits to the farmers.

Molecular epidemiology and in vitro antimicrobial susceptibility of Salmonella isolated from poultry in Kashmir

A total of 480 samples, comprising 429 faecal samples from healthy adult birds and 51 tissue samples from dead birds, were collected from four government poultry farms in the Kashmir valley from September 2007 to April 2008. In all, 33 Salmonella isolates were obtained. Of these, 28 (84.85%) isolates were Salmonella Gallinarum, 3 (9.09%) were Salmonella Enteritidis and the remaining 2 (6.06%) were Salmonella Typhimurium. All the isolates harboured the invA, sefA, stn and spvC virulence-specific genes. However, the sopB gene was found in only 90.9% of the isolates. Pulsed-field gel electrophoresis analysis of representative isolates revealed that the majority were related but a few belonged to different clones. The majority of the isolates were resistant to cefpodoxime, nalidixic acid and sulphadiazine and sensitive to chloramphenicol, cefotaxime and tetracycline. Isolation of multidrug-resistant Salmonella, including the zoonotically important serovars, revealed a potential threat not only to poultry but also to human health in Kashmir.

Testicular abscess caused by Salmonella para-typhi

This case is the first report of a bacteriologically proven testicular abscess in a child caused by Salmonella paratyphi 'A' in Pakistan that clinically simulates a testicular tumour. The case also emphasises that a course of 2 weeks antibiotic is sufficient for testicular abscess if complete surgical debridement is done.

Pyridine-derived γ-secretase modulators

SAR of a novel series of pyridine-derived γ-secretase modulators is described. Compound 5 was found to be a potent modulator in vitro, which on further profiling, was found to decrease Aβ42 and Aβ40, and maintain (or increase) the levels of total Aβ. Furthermore, representative compounds 1 and 5 demonstrated in vivo efficacy to lower Aβ42 in the brain without altering Notch processing in the peripheral.

Detection & characterization of Shiga toxin producing Escherichia coli (STEC) & enteropathogenic Escherichia coli (EPEC) in poultry birds with diarrhoea

BACKGROUND & OBJECTIVES

Limited information is available on shiga toxin producing Escherichia coli (STEC) in animals and birds from India. An outbreak of acute diarrhoea in poultry birds at Aizawl, Mizoram was investigated for detection and characterization of STEC and enteropathogenic E. coli (EPEC).

METHODS

E. coli was isolated and identified from rectal swabs, intestinal contents, heart blood and spleen of 19 poultry birds that died due to acute diarrhoea during the outbreak. Phenotypic characterization was done by standard bacteriological and biochemical techniques. All the isolates were serotyped based on their somatic antigens. Virulence genes (stx 1, stx 2, eaeA and hlyA) were detected by multiplex PCR assay.

RESULTS

A total of 42 E. coli isolates were obtained, of which 24 belonged to 3 serogroups (O64, O89 and O91) and the remaining 18 were untypable (UT). Altogether, 14 (33.33%) isolates carried at least 1 virulence gene, of which 10 (23.81%) and 4 (9.52%) were recorded as STEC and EPEC, respectively. Of the 10 STEC isolates, one carried only stx2 , one carried stx 2 and hlyA, four carried stx1 , stx2 and hlyA, two carried stx 1, eaeA and hlyA genes and two carried stx 1 and eaeA. Of the four EPEC isolates, two carried eaeA and hlyA, one carried only eaeA gene and 1 carried only hlyA gene.

INTERPRETATION & CONCLUSIONS

This is the first report on the involvement of STEC in poultry in India.

Peritoneal hydatidosis in a young girl

We report a case of peritoneal hydatidosis that occurred post laparotomy. Patient was diagnosed nine months after she had laparotomy for suspected acute appendicitis. The whole peritoneal cavity was studded with cysts. In view of diffuse involvement, patient was managed conservatively and showed response to medical therapy.

Dynamics of Aβ42 reduction in plasma, CSF and brain of rats treated with the γ-secretase modulator, GSM-10h

BACKGROUND

Allosteric modulation of γ-secretase is an attractive therapeutic approach for the treatment of Alzheimer's disease. We recently identified a novel γ-secretase modulator, GSM-10h, which effectively lowers Aβ42 production in cells and in amyloid precursor protein transgenic mice.

OBJECTIVE

Here, we describe the in vivo characterization of GSM-10h in a model of endogenous Aβ production.

METHODS

Rats were administered orally with GSM-10h, and the effect on Aβ levels in peripheral and central compartments was determined. In addition, the effect of GSM-10h on Notch processing was assessed.

RESULTS

Acute administration of GSM-10h to rats causes a dose-dependent decrease in the level of Aβ42 in plasma, CSF and brain, with little effect on the level of Aβ40 in these compartments. The magnitude of Aβ42 lowering in the CSF and brain was further enhanced upon sub-chronic administration of GSM-10h. No deleterious effect on Notch processing was evident in either of these studies. To further explore the dynamics of Aβ42 reduction in peripheral and CNS compartments, a time course study was conducted. In all compartments, the decrease in Aβ42 was greatest at 6 h after administration of GSM-10h. This decrease in Aβ42 was maintained for 9-15 h, after which time Aβ42 levels returned to baseline levels. Encouragingly, no rebound in Aβ42 levels beyond baseline levels was observed.

CONCLUSIONS

These findings support the γ-secretase modulator profile of GSM-10h, and highlight the utility of the rat for assessing the pre-clinical efficacy of γ-secretase modulators.

Collaboration between general practice and community psychiatric service, evaluation of consultation-liaison model

Background

There are many advantages to improve communication between primary care and Psychiatric services. In Ireland various models of liaison with primary care are still in early stages of experimentation in some parts. We devised a pilot project of consultation-liaison model in west of Ireland.

Methodology

There are 11 general practitioners working in the catchment area. All of them were given information and five agreed to participate. Based on random allocation two general practitioners were placed in experimental group. Three other general practitioners were allocated to control group. All patients from these surgeries were enrolled in study. In experimental group face to face meetings between psychiatrist and general practitioners were arranged before and after seeing patients in clinics. Feedback and exchange of information took place during these meetings. Meetings were arranged on monthly basis for six month starting in December 2009. While in the control group communication and referral was through usual method of writing letters.

Results

Assessment of data was based on comparison of outcome in two sets of patients and surgeries. We collected data regarding number of admissions, compliance with appointments, changes in medications, number of referrals to secondary care, number of discharges back to general practitioners. Results show quantitative benefits of collaborative model in the lines of more patients being discharged back to GP and less missed appointments. There was also trend of reduced admission rate but this was statistically not significant.

APP transgenic mouse models and their use in drug discovery to evaluate amyloid- lowering therapeutics

A critical requirement in the development of Alzheimer's disease (AD) therapeutics is a demonstration of the in vivo efficacy of compounds in pre-clinical disease relevant models. One of the most frequently used models in AD research are transgenic mice overexpressing mutant forms of human amyloid precursor protein (APP) that are associated with early-onset familial AD. These mice exhibit an age-dependent accumulation and deposition of amyloid -peptide (A) as extracellular plaques in the brain, and thereby depict one of the key pathologies observed in the brains of AD patients. Although these mouse models do not recapitulate all the pathological features of AD, they have been invaluable in the development of therapeutic agents aimed at lowering A production, inhibiting A deposition or facilitating A clearance. Further development of these APP transgenic models led to the incorporation of transgenes for human mutant presenilins, resulting in an accelerated A deposition rate and human mutant tau protein leading to neurofibrillary tangle-like pathology. The latter was a major advance in the development of AD models, as it allowed researchers to investigate the interplay between the two key pathologies of AD. This review highlights how APP transgenic mouse models have successfully been used in drug discovery to support the progression of A lowering therapeutics to clinical trials to ultimately test the 'amyloid hypothesis' of AD.

Detection of heat-stable and heat-labile enterotoxin genes of Escherichia coli in diarrhoeic faecal samples of mithun (Bos frontalis) calves by polymerase chain reaction

AIMS

To find out the prevalence of different serogroups of Escherichia coli (E. coli) and to detect heat-stable (ST) and heat-labile (LT) enterotoxin genes of enterotoxigenic E. coli (ETEC) from the faeces of mithun calves with diarrhoea.

METHODS AND RESULTS

Faecal samples obtained from 65 diarrhoeic mithun calves of under 2 months of age were examined for E. coli using polymerase chain reaction (PCR). Fifty-four E. coli isolates were obtained from those samples, which belonged to 38 different serogroups. Out of 54 isolates tested by PCR, two isolates (3.70%) belonging to serogroups O26 and O55 were found to possess gene that code for ST enterotoxin and one isolate (1.85%) belonging to serogroup O125 was found to carry LT enterotoxin gene.

CONCLUSIONS

Escherichia coli isolates from diarrhoeic mithun calves were found to possess ST and LT enterotoxin genes, which are designated as ETEC, and these isolates can be detected through PCR using specific primers.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study reports the isolation of ETEC possessing ST and LT enterotoxin genes for the first time and ETEC could be a cause of diarrhoea in mithun calves leading to calf mortality.

Fluoride and health hazards: community perception in a fluorotic area of central Rajasthan (India): an arid environment

India is among the 23 nations around the globe where health problems occur due to excess ingestion of fluoride (>1.5 mg/l) by drinking water. In Rajasthan, 18 out of 32 districts are fluorotic and 11 million of the populations are at risk. An exploratory qualitative survey was conducted to describe perception of the community regarding fluoride and related health problems in Central Rajasthan. A study on distribution and health hazards by fluoride contaminate in groundwater was performed in 1,030 villages of Bhilwara district of Central Rajasthan. One thousand thirty water samples were collected and analyzed for fluoride concentration. Fluoride concentration in these villages varies from 0.2 to 13.0 mg/l. Seven hundred fifty-six (73.4%) villages have fluoride concentration above 1.0 mg/l. Sixty (5.83%) villages have fluoride concentration above 5.0 mg/l with maximum numbers (24, 19.5%) from Shahpura tehsil. A detailed fluorosis study was carried out in 41 villages out of 60 villages having fluoride above 5.0 mg/l in the study age, sex, and occupation data were also collected. Four thousand, two hundred fifty-two individuals above 5 years age were examined for the evidence of dental fluorosis, while 1998 individuals above 21 years were examined for the evidence of skeletal fluorosis. The overall prevalence of dental and skeletal fluorosis was found to be 3,270/4,252 (76.9%) and 949/1,998 (47.5%), respectively. Maximum of 23.9% (1,016) individuals have mild grade of Dean's classification. Three hundred seventy-four (8.8%) individuals have severe type of dental fluorosis. The Dean's Community Fluorosis Index for the studied area in total is 1.62. Maximum CFI 3.0 was recorded from Surajpura of Banera Tehsil. Five hundred sixty-six (28.3%) individuals have Grade I type of skeletal fluorosis while only 0.6% (12) individuals have Grade III skeletal fluorosis. In conclusion, the prevalence and severity of fluorosis increased with increasing fluoride concentration. It was interesting to note that in some villages, the prevalence and severity of fluorosis were highest in subjects belonging to the economically poor community. Similarly, male laborers showed highest prevalence of fluorosis. Prevalence and severity of fluorosis were observed higher in subjects using tobacco, bettle nuts, and alcoholic drinks. In contrast, subjects using citrus fruits and having good nutritional status showed low prevalence.

Isolation of atypical enteropathogenic Escherichia coli and Shiga toxin 1 and 2f-producing Escherichia coli from avian species in India

AIMS

To study the prevalence and characterize atypical enteropathogenic Escherichia coli (EPEC) and Shiga toxin producing E. coli (STEC) in avian species in India.

METHODS AND RESULTS

Two hundred and twelve faecal samples collected from 62 chickens, 50 ducks and 100 pigeons were investigated for the presence of stx(1), stx(2), eae and ehxA virulence genes by multiplex PCR. In all, 42 E. coli isolates (25 chicken, 2 duck and 15 pigeon) possessed at least one virulence gene. Out of these, nine (4.24%) isolates were STEC and 33 (15.56%) were EPEC. All isolates from duck and chicken were EPEC while among 15 pigeon isolates nine (60%) were STEC and six (40%) were EPEC. Among the STEC isolates four each carried stx(1) or stx(2) and one possessed both stx(1) and stx(2). Subtype analysis of stx revealed the presence of stx(2f) in four STEC isolates. None of the STEC isolates carried stx(1c), stx(2c), stx(2d) or stx(2e). Isolates carrying stx(2f) demonstrated vero cell toxicity. One each belonged to serogroup O17 and O78, while one was rough and the other untypeable. All EPEC isolates were atypical as they lacked bfpA. This appears to be the first report of detection of stx(2f) from India.

CONCLUSIONS

The study established the presence of stx(1) and stx(2f) containing E. coli in pigeons and atypical EPEC in poultry in India. Pigeons might serve as vectors for transmission of STEC to environment and humans.

SIGNIFICANCE AND IMPACT OF THE STUDY

Taking into account the close contact between fanciers and pigeons, these findings warrant a more critical appraisal of these zoonotic pathogens in pigeons and humans.

Distinct pattern of mutations of conserved regions of TP53 in colorectal cancer patients in the Kashmir population: an emerging high-risk area

Background:

Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity. The Kashmir valley, in Northern India, has been described as a high-risk area for colorectal cancer.

Aim:

The aim was to make a preliminary attempt to study mutations in exons 5–8 (the DNA binding domain) of the tumour suppressor gene TP53 in 42 CRC patients from Kashmir.

Materials and methods:

The study population consisted of 42 patients diagnosed with colorectal cancer. Mutations in exons 5–8 of the TP53 gene were detected by means of single-strand conformation polymorphism (SSCP). All samples that showed different band migration patterns in the SSCP were confirmed by sequencing.

Results:

The 28 mutations were found in the TP53 gene in 19 patients, comprised 23 substitutions (17 transitions + six transversions), and five insertions. The 23 substitutions represent 18 missense mutations, leading to amino acid substitutions, two nonsense mutations, leading to stop codons, while the remaining three were silent mutations. The five insertions represented frameshifts. Two of 28 mutations (7.14%) have not been previously reported in colon cancer samples and were identified as novel TP53 mutations. Comparison of the mutation profile with other ethnic populations and regions reflected both differences and similarities indicating co-exposure to a unique set of risk factors.

Conclusions:

Mutation of the TP53 gene is one of the commonest genetic changes in the development of human colorectal cancer. The high frequency of TP53 gene mutations implicates TP53 as a predominant factor for colorectal cancer in the high-risk ethnic Kashmir population.