The alveolar-capillary membrane diffusing capacity and the pulmonary capillary blood volume in heart transplant candidates

OBJECTIVES: To determine the mechanism of impairment of pulmonary transfer factor for carbon monoxide (TL(CO)) in heart transplant candidates, as this is the most common lung function abnormality. SETTING: Regional cardiopulmonary transplant centre. METHODS: TL(CO) and its components (the diffusing capacity of the alveolar-capillary membrane (D(M)) and the pulmonary capillary blood volume (V(C))) were measured using the Roughton and Forster method and the single breath technique in 38 patients with severe chronic heart failure awaiting heart transplantation (mean age 51 years, range 19 to 61; mean left ventricular ejection fraction 12.8%). Results were compared with data from 26 normal subjects (mean age 47 years, range 27 to 62). RESULTS: Mean per cent predicted TL(CO), D(M), and V(C) were significantly reduced in patients (69.9%, 81.4%, and 80.2% of predicted, respectively) compared with controls (97.7%, 100.1%, and 102.3% of predicted, respectively, p < 0.001). The relative contribution of the two components of TL(CO) in patients was similar to that of normal subjects, with each component accounting for approximately 50% of the total resistance to diffusion (1/TL(CO)). CONCLUSIONS: TL(CO) impairment in patients with severe chronic heart failure awaiting heart transplantation results from a proportionate reduction in both D(M) and V(C), suggesting a significant disturbance of the pulmonary vascular bed.     

Spectrum and antibiotic sensitivity of bacteria contaminating the upper gut in patients with malabsorption syndrome from the tropics

Background  

Various causes of malabsorption syndrome (MAS) are associated with intestinal stasis that may cause small intestinal bacterial overgrowth (SIBO). Frequency, nature and antibiotic sensitivity of SIBO in patients with MAS are not well understood.     

Use of site-directed mutagenesis to identify an upstream regulatory sequence of sodA gene of Escherichia coli K-12.

Mn-containing superoxide dismutase (SodA; superoxide:superoxide oxidoreductase, EC 1.15.1.1) biosynthesis in Escherichia coli is regulated by several environmental stimuli. The DNA sequence of sodA shows the presence of a potential binding site for a regulatory protein(s) at the -35 region. To explore the possible role of this region in the regulation of sodA, we used oligonucleotide-directed site-specific mutagenesis to change the sequence of nucleotides -48 through -44 from 5'-GGCAT-3' to 5'-TTACG-3'. We studied the effect of this altered sequence on the expression of sodA. The data showed that the altered sequence resulted in the constitutive expression of the gene. Thus, E. coli harboring a plasmid containing the mutated sodA gene (pSNM6) were uninducible by paraquat in aerobiosis or by 2,2'-dipyridyl in aerobiosis or anaerobiosis. Furthermore, a multicopy plasmid containing the mutated sodA failed to titrate the repressor molecules present in an E. coli strain carrying the sodA-lacZ fusion. In contrast, multicopy plasmids containing the wild-type sodA gene were able to titrate the repressor protein and to cause the anaerobic induction of beta-galactosidase in this sodA-lacZ fusion strain. These results indicate that the region within and around the mutated sequence probably plays an important role in sodA regulation and that the mutation disrupts a sequence that interacts with the repressor.     

Genetics of coronary artery disease – A clinician's perspective

Coronary artery disease (CAD) is the major cause of fatality and disability among all cardiovascular diseases (CVD). Intricate interactions of genes and environment dictate the outcomes of CAD. Technological advances in the different fields of genetics including linkage studies (LS), candidate gene studies (CGS) and genome-wide association studies (GWA studies) have augmented the knowledge of pathogenesis of CAD. LS were more successful in identifying genetic variants among monogenic disease. GWA studies were relatively popular in identification of variation in polygenic disease. Until now, GWA studies recognized about 50 loci determining around 6% of the heritability in CAD. Clinical utility of the above knowledge would result in better CAD management, but validation of the variants in native population is warranted for active adoption into the clinic. The major aim of this review is to provide an adequate perspective of our current understanding and advances of genetics in CAD.     

2-Phenylindole and Arylsulphonamide: Novel Scaffolds Bactericidal against Mycobacterium tuberculosis

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Diagnostic utility of urine cytology in detection of decoy cells in renal transplant patients: Report of five cases and review of literature

BK polyoma virus (PV) is one of the commonest post‐transplant viral infections, affecting approximately 15% of renal transplantation recipients, leading to graft failure in more than half of cases. The epithelial cells with polyoma viral inclusions in urine cytology specimens are termed “decoy cells” to caution pathologists not to misdiagnose these cells as cancer cells. The infected cells in urinary sediments are characterized by enlarged nucleus, basophilic intranuclear homogenous inclusions, and ground glass chromatin, which may cause diagnostic error in urine cytology. We report five cases of renal transplant patients, in which urine sample was positive for decoy cells. Routine urine cytology of post renal transplant patients with worsening renal function is a useful screening procedure to rule out PV reactivation, before ascertaining transplant rejection. Its cost‐effectiveness in addition to the short processing time makes it an invaluable tool in the evaluation of transplant recipients with symptoms suggestive of graft rejection.     

Clinico-Epidemiological Profile of Breakthrough COVID-19 Infection among Vaccinated Beneficiaries from a COVID-19 Vaccination Centre in Bihar,India

BackgroundWhen the whole world is fighting in an unprecedented pace against COVID-19 pandemic, the breakthrough COVID infections poise to dampen the rapid control of the same. We carried out this project with two objectives; first, to estimate the proportion of breakthrough COVID-19 infection among completely vaccinated individuals and second, to study the clinico-epidemiological profile of breakthrough COVID-19 infections among them.MethodsThis cross-sectional analytical study was conducted among 2703 fully vaccinated individuals from AIIMS, Patna COVID Vaccination Centre (CVC), Bihar, India. The participants were selected randomly using a systematic sampling technique from the list of beneficiaries maintained at the CVC. Telephonic interviews were made to collect the information by trained data collectors.ResultsA total of 274 fully vaccinated beneficiaries [10.1% (95% CI: 9.1%, 11.4%)] were diagnosed with breakthrough COVID-19 infection. The infections were more among males (10.4%) and the individuals aged ≤29 years (12.5%). The beneficiary categories, the healthcare-worker and the frontline-worker, were identified as predictors of the breakthrough COVID infections. Only one in three participants had adopted adequate COVID appropriate behaviour following the full vaccination. The majority of the breakthrough infections occurred during the second wave of COVID-19. The majority of the individuals with breakthrough infections were asymptomatic and no death was reported among them.ConclusionOne in every ten fully vaccinated individuals can get the breakthrough COVID infections. The healthcare-worker and the frontline-worker had independent risk of getting the breakthrough infections. Very few with breakthrough infections were serious and no death was reported among them.