Identification of an ion channel-forming motif in the primary structure of CFTR, the cystic fibrosis chloride channel.

Synthetic peptides with sequences representingputative transmembrane (M) segments of CFTR (the cystic fibrosis transmembraneconductance regulator) were used as tools to identify the involvement of suchsegments in forming the ionic pore of the CFTR Cl- channel. Peptides withsequences corresponding to M2 and M6 form anion-selective channels afterreconstitution in lipid bilayers. In contrast, peptides with the sequences ofM1, M3, M4, and M5, or peptides of the same amino acid composition as M2 and M6but with scrambled sequences, do not form channels. Conductive heterooligomersof M2 and M6 exhibit a single channel conductance of 8 pS (in 0.15 M KCl) and a95% selectivity for anions over cations, properties that emulate both theconductance and the selectivity of the authentic CFTR channel. Theidentification of sequence-specific motifs that account for key functionalattributes of the CFTR channel suggests that such modules may representfundamental units of function and are plausible constituents of the pore-formingstructure of the CFTR Cl- channel.     

Cardiac injuries--a clinical and autopsy profile

One hundred two patients sustaining cardiac injuries over a 4-year period were analysed to highlight the natural history of the cardiac injuries. There were 45 blunt, 36 stab, and 21 gunshot injuries. The injury involved the ventricle in 85, atrium in seven, pulmonary artery in five cases, and resulted in crush injury to the heart in the remaining five cases. Thirty-three patients (32.3%) died on the scene and 58 (56.9%) died during the transportation. Only 11 patients (10.8%) reached the hospital alive, and ten of these patients survived following thoracotomy and repair of the cardiac injury. The factors influencing the natural course of cardiac injury were analysed: 2.2% of patients with blunt cardiac trauma reached the hospital alive compared to 19.4% with stab and 14.3% with gunshot injuries; ventricular injuries had a greater prehospital mortality compared to atrial or pulmonary artery injuries; 11.3% of patients sustaining injury to right ventricle reached the hospital alive compared to 3% of those with left ventricular injuries. These data emphasize the need for rapid transport, immediate recognition, and aggressive surgical management, to make a favourable impact on the natural history of cardiac injuries.     

Assessment of atmospheric microbial contamination in a mobile dental unit.

INTRODUCTION: Bioaerosols are important considerations in infection control as well as in occupational health. Bioaerosols may carry potentially hazardous microbes, viruses, fungi, allergens, and other toxic substances that may harm the dental operator, patient, and the dental assistant by causing nosocomial infections. OBJECTIVE: To assess the level of atmospheric microbial contamination before, during, and after dental treatment procedures in the dental operatory of a mobile dental unit (MDU). MATERIALS AND METHODS: The study included three treatment sessions on different working days, with an interval of one month. The MDU was fumigated before the start of the study. Brain Heart Infusion Agar with 5% sheep blood was used to collect the gravitometric settling of aerosols produced before, during, and after dental treatment procedures. The agar plates were sent for aerobic and anaerobic culture. RESULTS: The results showed that atmospheric microbial contamination (CFUs/plate) was 4 times higher during working sessions as compared to the levels before the working sessions. At the end of the working day, aerosols decreased by almost 3 times that seen during work. CONCLUSION: The aerosols increased during and after work sessions. This shows the increased risk of transmission of infectious agents to the dentists who work in the MDU. Hence, all necessary preventive measures should be advised and need to be followed strictly.     

Stress signaling through Ca2+/calmodulin-dependent protein phosphatase calcineurin mediates salt adaptation in plants

Calcineurin (CaN) is a Ca²⁺- and calmodulin-dependent protein phosphatase (PP2B) that, in yeast, is an integral intermediate of a salt-stress signal transduction pathway that effects NaCl tolerance through the regulation of Na⁺ influx and efflux. A truncated form of the catalytic subunit and the regulatory subunit of yeast CaN were coexpressed in transgenic tobacco plants to reconstitute a constitutively activated phosphatase in vivo. Several different transgenic lines that expressed activated CaN also exhibited substantial NaCl tolerance, and this trait was linked to the genetic inheritance of the CaN transgenes. Enhanced capacity of plants expressing CaN to survive NaCl shock was similar when evaluation was conducted on seedlings in tissue culture raft vessels or plants in hydroponic culture that were transpiring actively. Root growth was less perturbed than shoot growth by NaCl in plants expressing CaN. Also, NaCl stress survival of control shoots was enhanced substantially when grafted onto roots of plants expressing CaN, further implicating a significant function of the phosphatase in the preservation of root integrity during salt shock. Together, these results indicate that in plants, like in yeast, a Ca²⁺- and calmodulin-dependent CaN signal pathway regulates determinants of salt tolerance required for stress adaptation. Furthermore, modulation of this pathway by expression of an activated regulatory intermediate substantially enhanced salt tolerance.     

Molecular epidemiology of norovirus variants detected in children under five years of age in Hyderabad,India

PurposeNoroviruses are common viral agents in acute diarrhea in all age groups worldwide. Norovirus has been classified into 10 genogroups, GI to GX with over 48 genotypes among them the GII.4 genotype has evolved over time with a clear pattern of periodic variant replacement. Immunity is strain or genotype specific with little or no protection conferred across genogroups. The present study was aimed to determine the epidemiology, prevalent genotypes of norovirus in children below five years of age in the Hyderabad region, India.MethodsThe stool samples and clinical data were collected from 458 children below 5 years of age comprising of cases with acute gastroenteritis (n ?= ?366) and a control group (n ?= ?92) admitted to the pediatric ward. All the samples were tested for Norovirus by ELISA and RT-PCR. Sequencing was done for predominant strains.Results10.3% (n ?= ?38) of cases and 3.2% (n ?= ?3) of the control group were found to be Norovirus positive. Predominant genotypes were GII-82.5% followed by GI-12.5%.ConclusionSequencing and Phylogenetic analyses of 20 GII.4 strains was done. All of the isolates are clustered away from published the GII.4 variants thus suggesting the appearance of a new variant.     

Use of total cholesterol/albumin ratio as an alternative to high density lipoprotein cholesterol measurement.

In a study of apparently healthy males, we noted a correlation between serum albumin and high density lipoprotein cholesterol (HDL-C) (r = 0.32, p less than 0.001). We then correlated the total cholesterol:albumin ratio (TC:Alb) with the TC:HDL-C ratio (r = 0.89, p less than 0.001). We used the TC:Alb ratio to determine whether this was better than TC by itself in predicting whether an individual had a TC:HDL-C ratio of less than or greater than or equal to 5. The ratio performed better than TC and correctly classified 89% of individuals (66% with TC) (p less than 0.001). Since measurements of TC and Alb are routinely available on multichannel analysers, use of this ratio would provide a less expensive alternative to HDL-C measurement.     

Diagnostic role of fine-needle aspiration of bone lesions in patients with a previous history of malignancy

At the present time fine-needle aspiration (FNA) is considered a routine diagnostic procedure in evaluating neoplastic vs. nonneoplastic lesions in many organs, with high sensitivity and specificity. The purpose of this study was to assess the utility of FNA in areas of diagnostic difficulty and its limitations in evaluating bone lesions in patients with a previous history of malignancy. From 1989 to 2000, 249 CT-guided FNAs of bone lesion were performed at our institutions; 187/249 (75.1%) patients had a previous history of malignancy. Aspirated material was air-dried for Diff-Quik stain or fixed in ethanol for Papanicolaou staining. Subsequent surgical tissue was available in 69/187 (36.9%) of the cases. There were 114 males and 73 females, ages 14-86 yr (mean, 64 yr). The primary tumor site was lung 49, genitourinary 46, breast 31, gastrointestinal 28, hematopoietic 26, soft tissue/skin 5, and thyroid 2. There were 125 FNAs of the vertebral spine, 19 from the pelvis, 11 from the ribs, 9 from the sternum, 5 from the femur, and 18 from miscellaneous bone sites. Out of 187, 166 (88.7%) were malignant aspirates confirming the patients' primary malignancies. The most common malignancy encountered was adenocarcinoma, 126/187 (67.4%). Surgical tissue was available for review in 69 patients and the results were in agreement with the FNAs diagnosis in all cases. Nine out of 187 (4.8%) cases were diagnosed as marrow elements on cytological material. These patients have been followed for 1-9 yr and have failed to reveal signs or symptoms of clinical recurrence. Three out of 187 (1.6%) cases showed osteomyelitis. Nine out of 187 (4.8%) were unsatisfactory specimens, with biopsy follow-up available in four cases, showing three metastatic tumors and one case of osteomyelitis. FNA of metastatic bone lesions is a major step in pretreatment diagnosis. On satisfactory specimens, the cytological diagnosis viewed in the clinical-radiological context proves to be similar to surgical diagnosis. FNA is an excellent technique with a high accuracy rate in assessing metastatic bone lesions.     

Application of adjunct techniques in cytologic material in the diagnosis of rhabdomyosarcoma: case report and review of the literature

A 4(1/2)-yr-old female presented with right-sided pleural effusion and a retroperitoneal mass. Cytologic analysis of the pleural fluid yielded malignant small round blue cells, which were noncohesive, 3-4 times the size of lymphocytes. The malignant cells had hyperchromatic, pleomorphic nuclei with moderate amounts of vacuolated cytoplasm. A few fiber-shaped cells were also seen. Immunostains for desmin, muscle-specific actin were positive; ultrastructural findings of thick and thin actin-myosin filaments confirmed the diagnosis of embryonal rhabdomyosarcoma. This case illustrates the importance of performing appropriate immunohistochemical stains and ultrastructural studies on cytological material to arrive at a definitive diagnosis.     

Effects of diet on the lipid composition of Echinostomacaproni (Trematoda) in ICR mice

High-performance thin-layer chromatography (HPTLC) was used to determine neutral lipids and phospholipids in the intestinal trematode Echinostomacaproni from experimentally infected ICR mice fed a high-fat diet (hen's egg yolk) as compared with worms from mice fed a standard laboratory diet. Worms were removed from the hosts at 2, 3, and 4 weeks postinfection (p.i.). Analysis by TLC-densitometry showed significantly greater amounts of triacylglycerols and free sterols at 2, 3, and 4 weeks p.i. in worms from mice on the high-fat diet as compared with worms from mice on the standard laboratory diet. Significantly greater amounts of phosphatidylcholine and phosphatidylethanolamine were found in worms from mice on the high-fat diet as compared with worms from those on the standard diet at 2 weeks p.i. but not at 3 and 4 weeks p.i. The results of this study suggest that the host diet influences the lipid content of E. caproni adults.