Brown tumor of the knee as the first presentation of primary hyperparathyroidism caused by parathyroid adenoma: A case report.

Brown tumor of the knee is a focal benign cystic lesion of bone. The etiopathogenesis of brown tumor is believed to be abnormal bone metabolism in patients with hyperparathyroidism. We present a case of a 32-year-old male with recurrent knee pain, weakness of the lower limb and a nodular mass on left inferior lobe of thyroid. Timely identification of the underlying cause and localization of lesion(s) is important because the management and prognosis vary based on the etiology. The diagnosis of a brown tumor is the result of the sum of the medical history of patients with clinical, radiographic imaging, histopathological, hematological, and biochemical laboratory investigations.

A fast survey on recent developments in designing colorimetric and fluorescent sensors for the selective detection of essential amino acids.

Owing to the biological significance of various amino acids, developing accurate and cost-effective sensing techniques for the selective detection of amino acids has recently attracted growing interest. This review discusses the recent advancements of chemosensors in the selective detection of only essential amino acids out of a total of twenty amino acids, which have been applied in chemosensing research, and the mechanism of their action. The focus is directed towards the detection of the most important essential amino acids, like leucine, threonine, lysine, histidine, tryptophan and methionine, since isoleucine and valine are yet to be explored in regard to chemosensing. According to their chemical and fluorescence properties, different sensing techniques, such as the reaction-based approach, DNA-based sensors, nanoparticle formation, coordination ligand binding, host-guest chemistry, the fluorescence indicator displacement (FID) approach, electrochemical sensors, carbon dot-based sensors, MOF-based sensors and metal-based techniques, have been described.

An affinity-based genome walking method to find transgene integration loci in transgenic genome.

Identifying a good transgenic event from the pool of putative transgenics is crucial for further characterization. In transgenic plants, the transgene can integrate in either single or multiple locations by disrupting the endogenes and/or in heterochromatin regions causing the positional effect. Apart from this, to protect the unauthorized use of transgenic plants, the signature of transgene integration for every commercial transgenic event needs to be characterized. Here we show an affinity-based genome walking method, named locus-finding (LF) PCR (polymerase chain reaction), to determine the transgene flanking sequences of rice plants transformed by Agrobacterium tumefaciens. LF PCR includes a primary PCR by a degenerated primer and transfer DNA (T-DNA)-specific primer, a nested PCR, and a method of enriching the desired amplicons by using a biotin-tagged primer that is complementary to the T-DNA. This enrichment technique separates the single strands of desired amplicons from the off-target amplicons, reducing the template complexity by several orders of magnitude. We analyzed eight transgenic rice plants and found the transgene integration loci in three different chromosomes. The characteristic illegitimate recombination of the Agrobacterium sp. was also observed from the sequenced integration loci. We believe that the LF PCR should be an indispensable technique in transgenic analysis.

Campylobacter jejuni infection in Guillain-Barré syndrome: a prospective case control study in a tertiary care hospital.

BACKGROUND: Guillain-Barré syndrome (GBS), is a common post-infectious polyradiculoneuropathy worldwide. The commonest implicated causative organism the world over is Campylobacter jejuni (C. jejuni). This study was carried out to determine the relationship between C. jejuni infection and GBS in an Indian setting. MATERIALS AND METHODS: This prospective study was carried out on a cohort of 50 patients with GBS who were treated in a tertiary care hospital in India. Based on electrophysiological findings the patients were divided into various subtypes. Serology for C. jejuni (Immunoglogulin G, IgG and Immunoglogulin, IgM) using an enzyme-linked immunosorbent assay method (ELISA) was done both in patients and 40 age, sex and geographically matched controls. RESULTS: Evidence of recent C. jejuni infection was present in 30% of GBS patients compared to 8% of controls (15/50 vs. 3/40 P<0.005). Eight (47%) C. jejuni-positive patients reported symptoms of gastroenteritis 4-30 days (mean 13 days) prior to onset of GBS. Of the 15 patients with evidence of C. jejuni infection, 10 (67%) patients had axonal type of GBS. Axonal variety of GBS presented in a younger age group compared to acute inflammatory demyelinating polyradiculoneuropathy (AIDP) patients (mean age: axonal vs. AIDP: 30.11 + 13.73 vs. 40.2 + 18.77). C. jejuni-positive patients presented mainly in spring and winter and had a similar age and sex incidence as compared to the rest of the GBS patients. CONCLUSIONS: Preceding C. jejuni infection is common among GBS patients and is often associated with the axonal variety of GBS. Axonal variety of GBS generally presents in a younger age group as compared to AIDP.

Clostridium difficile toxin and faecal lactoferrin assays in adult patients.

Clostridium difficile is the primary aetiological agent of antibiotic-associated diarrhoea. The faecal lactoferrin (FL) assay is a simple in vitro test which is highly sensitive to the presence of a marker of polymorphonuclear cells. We evaluated the use of the FL assay in conjunction with the C. difficile toxin assay in faecal samples obtained from 231 adult patients. The relationship between C. difficile toxin and FL in both negative and positive status was highly significant statistically (P < 0.001). Therefore, the FL assay performed simultaneously with the C. difficile toxin assay can help rule out asymptomatic carriage of C. difficile.

False-positive reactions with enzyme-linked immunosorbent assay of Mycobacterium tuberculosis antigens in pleural fluid.

The value of enzyme-linked immunosorbent assay (ELISA) for the diagnosis of tuberculous pleural effusion has not been defined. We performed ELISA by a double antibody sandwich technique with anti-BCG antibody in the solid phase to detect Mycobacterium tuberculosis antigen in pleural fluid from 36 patients with pleural effusion (tuberculosis 15, lung cancer 12, miscellaneous 9). Pleural fluids from 12 of the tuberculosis patients, 12 of the cancer patients and one patient in the miscellaneous group had optical densities above the cut-off point. False-positive reactions in patients with lung cancer limit the usefulness of ELISA with conventional anti-BCG antibody for detection of M. tuberculosis antigen.

Detection of a Mycobacterium leprae cell wall antigen in the urine of untreated and treated patients.

A total of 90 leprosy patients, 12 household contacts and 10 normal subjects were studied for the detection of Mycobacterium leprae cell wall antigen in urine using monoclonal antibody (ML30A2 IgG). In untreated multibacillary leprosy (BL-LL) the M. leprae cell wall antigen could be demonstrated in the urine of 14 (64%) patients by immunofluorescence (IF) and 22 (100%) by ELISA. In untreated paucibacillary leprosy (TT-BT), it could be demonstrated in 3 (11.5%) and in 13 (50%) patients by IF and ELISA methods respectively. All but 1 household contact (later confirmed to have BL leprosy) and all 10 normal subjects' urine was negative for M. leprae cell wall antigen by both methods. The same antigen was, however, demonstrated in urine of 50% paucibacillary patients who had received 6 months of treatment and in 68% multibacillary patients who had received 24 months of WHO recommended multidrug therapy. M. leprae cell wall antigen assays in urine will not be useful in the follow-up of leprosy patients on multidrug therapy.

Bacillaemia in leprosy and effect of multidrug therapy.

Twenty-five patients of bacilliferous leprosy (17 LL, 8 BL) were studied by the modified haemolysis method for occurrence of bacillaemia and its clearance after two multidrug therapy regimens. Acid-fast bacilli were found in 76% of all patients and in 88.2% LL and 50% BL patients. Bacillaemia occurred with significantly reduced frequency in patients with type II reaction. Acid-fast bacilli were demonstrable in peripheral blood after 1 month in one patient on MDT of an Indian Working Group and 3 lepromatous patients on WHO multidrug therapy. However, bacillaemia could not be demonstrated in any patients after 2 and 3 months of treatment with both regimens.

Epidermal calmodulin levels in psoriasis before & after therapy.

Epidermal calmodulin (CaM) levels were measured in the involved and uninvolved skin in 26 psoriasis patients before and after treatment either with dithranol topically or methotrexate orally. The mean epidermal calmodulin levels (+/- SD) in the involved and uninvolved psoriatic skin before treatment were 21.99 +/- 10.22 and 11.97 +/- 3.50 in the patients to be treated with short contact dithranol therapy (SCDT) while it was 19.46 +/- 8.13 and 11.27 +/- 7.23 in the patients to be treated with systemic methotrexate. Clearance of psoriatic lesions was associated with a significant fall (P less than 0.05) in epidermal calmodulin, activity irrespective of the treatment modality used. Also, there was a significant reduction (P less than 0.05) in the calmodulin levels in the epidermis of uninvolved skin following successful treatment.

Antibiotic associated diarrhoea and enterocolitis.

C. difficile is the major aetiological agent of AAD and PMC and results from overgrowth of C. difficile already present endogenously or of newly acquired exogenous organisms after suppression of competing gut flora. C. difficile produces two kinds of toxins A and B. These toxins attack the colonic mucosa which becomes necrotic with the formation in fulminating cases of an exudative pseudomembrane. Toxigenic and non-toxigenic strains of C. difficile may be present together in an individual suffering from AAD. There is substantial variation among strains with respect to the quantity of lethal toxin produced. There are several strategies available for the investigation of C. difficile associated disease. Detection of toxins by neutralization with C. sordelli antitoxin is an easy, simple and sensitive method. Methods to deal effectively with silent carriers are not known because the routine administration of antibiotic treatment in an attempt to eradicate the carrier state would in fact boomerang by promoting C. difficile associated enteric disease rather than eliminating C. difficile.

Bacterial profile of dairy products sold in Chandigarh.

Gastrointestinal infections are known to occur due to bacterial contamination of dairy products. A total of 141 dairy products viz. kulfi, ice cream and softy samples were investigated bacteriologically. Staphylococcus was the predominant organism isolated followed by Klebsiella pneumoniae, Escherichia coli and Campylobacter. Two of the samples also yielded Yersinia. The total bacterial counts obtained ranged from 2 x 10(1) to 5.2 x 10(11) colony forming units per ml (CFU/ml) for kulfi, 4 x 10(1) to 9 x 10(9) CFU/ml for ice cream and 2 x 10(1) to 2 x 10(10) CFU/ml for softy samples. The high degree of bacterial contamination seen indicates poor hygienic conditions and faults in manufacturing/handling of dairy products during and after processing and production.

Enteropathogenic Escherichia coli isolates in paediatric diarrhoea.

Enteropathogenic Escherichia coli (EPEC) are known to cause infantile enteritis. We studied the prevalence of EPEC in paediatric patients with acute and persistent diarrhoea. A total of 56 stool samples from paediatric patients were studied. There were 28 significant bacterial isolates. Of these 21 were untypable E. coli, 5 were typable E. coli, four of which belonged to members considered to be enteropathogenic. Non E. coli isolates grown in pure culture were one each of Pseudomonas aeruginosa and Citrobacter freundi. The study reveals the definitive role of EPEC in childhood diarrhoea at all age groups and emphasizes the need for characterisation of all significant E. coli isolates in this age group.

Indigenous rapid diagnostic method for Escherichia coli O157:H7.

Rapid methods for detection of Escherichia coli O157: H7 diarrhoea are preferred to limit differential diagnostic evaluation including invasive procedures. Fifty stool samples from children and adult patients having diarrhoea and ten control samples from volunteers without diarrhoea were collected. Each sample was inoculated into two tubes containing peptone water and one containing MacConkey broth. They were incubated for 5 hours or longer till growth occurred. The first tube of peptone water with growth was tested for production of indole. All samples were tested for enzyme beta-glucuronidase in the pellet of the second peptone water growth. The MacConkey broth growth was tested with latex beads sensitized separately with antisera to E. coli O157 and E. coli H7. All indole positive and beta glucuronidase negative samples with positive agglutination with E. coli O157 and H7 coated latex beads were taken as E. coli O157: H7 positive samples. Three out of 50 diarrhoeic samples were found to be positive for E. coli O157:H7. Confirmation of the results of our rapid assay was done by parallel conventional culture of faecal specimens on sorbitol MacConkey agar. Our rapid assay required only 7-10 hours compared to the conventional technique where the report is available only on the third day. It can therefore be used routinely for initial screening of faecal specimens for E. coli O157: H7.

Detection of Clostridium difficile toxin by an indigenously developed latex agglutination assay.

An indigenously developed latex agglutination assay using C. sordelli antitoxin was used to screen 211 stool samples received from hospitalized patients. Of 126 samples from patients receiving single to multiple antibiotics for various ailments, 38 (30%) were positive by the toxin assay, whereas only 6/85 (7%) of samples of patients not receiving antibiotics were also positive. Thus, of 211 samples a total of 44 (20.8%) were positive by our toxin assay, giving titers ranging from 1 in 5 to 1 in 320. The test developed by us is simple, rapid, easy and reliable and can be easily adapted to all microbiology laboratories.

Adenosine triphosphate content of Mycobacterium leprae by percoll buoyant density centrifugation.

Thirty nine untreated patients of bacilliferous leprosy with a mean bacteriological index of 4.8 and morphological index of 1.3% formed the study group. Adenosine triphosphate assay was carried out by (i) enzyme treatment method in 18 patients and (ii) percoll buoyant density gradient method in 21 patients. ATP content obtained by percoll buoyant density gradient method was significantly higher than that obtained by enzyme treatment method. Percoll buoyant density centrifugation for purification and isolation of bacilli from human leproma is simplier, quicker and can serve as an alternate method of enzyme treatment.

Effect of in vitro formed immune complexes on macrophage functions of Mycobacterium leprae infected mice.

Nonspecific macrophage functions were studied in Mycobacterium leprae infected and preformed immune complex (IC) administered normal (NI) and thymectomized/irradiated (TRI) mice at different time periods. Uninfected controls given IC were also included. Significant decrease in the chemotaxis, phagocytosis and bactericidal activities of macrophages obtained from infected groups compared to their controls were observed. Phagocytic and chemotactic activities of macrophages were normal but intracellular killing was seen to be depressed in studies conducted in normal and thymectomized immunosuppressed groups (Vaishnavi et al., 1985, Kumar et al, 1987) which were not administered with preformed IC.

ADCC function in Mycobacterium leprae inoculated normal and immunosuppressed mice.

Normal and immunosuppressed mice were inoculated with Mycobacterium leprae obtained from untreated lepromatous patients. Besides monitoring the AFB counts in the footpads at 3,6 and 9 months post inoculation, antibody dependent cellular cytotoxicity (ADCC) function was studied. The ADCC function seen to be largely unaltered in the M. leprae infected animals, comparable to the observation made in human leprosy.

Circulating immune complexes in normal and immunosuppressed mice infected with Mycobacterium leprae.

Mycobacterium leprae infection was produced through the footpads in normal and immunosuppressed mice. Circulating immune complexes were detected by specific binding test and by conglutinin binding assay for specific and total immune complexes respectively in the sera of these mice during different periods of infection. Out of the total 30 samples tested from the infected groups, 3 were positive by specific binding test and 5 by conglutinin binding ELISA. The implications of the findings in relation to human leprosy are discussed.

Bacillaemia in leprosy: correlation with slit-skin and nasal smears.

Twenty five multibacillary patients (BL/LL) were studied for bacillaemia. Majority (76%) showed acid fast bacilli in peripheral blood. There was good correlation between bacillary load in peripheral blood and bacteriological index (BI) but poor correlation with morphological index (MI) of skin slit smear and BI/MI of nasal smear.