Trends in the epidemiology of opportunistic fungal infections: predisposing factors and the impact of antimicrobial use practices

In the past decade, the frequency of opportunistic fungal infections has increased, and the spectrum of fungal pathogens has changed. The increasing number of susceptible hosts, the introduction of newer modalities for hematopoietic stem cell transplantation, the evolution of organ transplantation practices, the use of novel immunosuppressive agents, and current antimicrobial prophylactic strategies have likely contributed to the changing epidemiology of invasive mycoses. The introduction of azoles more than a decade ago has had a profound impact on curtailing candidal infections. However, a dramatic increase in azole-resistant Candida species and mold infections has been documented. The trends in time of onset, spectrum, and frequency of infections due to invasive molds and opportunistic yeasts are unique for different fungi and vary between subsets of immunocompromised hosts. This review discusses the implications of these trends for guiding judicious use of antimicrobial prophylactics and for unraveling the pathophysiological basis of fungal infections.

Asynchronous replication and allelic exclusion in the immune system

The development of mature B cells involves a series of molecular decisions which culminate in the expression of a single light-chain and heavy-chain antigen receptor on the cell surface. There are two alleles for each receptor locus, so the ultimate choice of one receptor type must involve a process of allelic exclusion. One way to do this is with a feedback mechanism that downregulates rearrangement after the generation of a productive receptor molecule, but recent work suggests that monoallelic epigenetic changes may also take place even before rearrangement. To better understand the basis for distinguishing between alleles, we have analysed DNA replication timing. Here we show that all of the B-cell-receptor loci (mu, kappa and lambda) and the TCRbeta locus replicate asynchronously. This pattern, which is established randomly in each cell early in development and maintained by cloning, represents an epigenetic mark for allelic exclusion, because it is almost always the early-replicating allele which is initially selected to undergo rearrangement in B cells. These results indicate that allelic exclusion in the immune system may be very similar to the process of X chromosome inactivation.

Synthesis and Regulation of Folate Coenzymes During early Germination in Vigna radiata

Folate profiles and DNA synthesis were studied during the early germinating period in Vigna radiata. Total folate andmethyl folate forms were increased from 4 to 32 hours during germination period studied. Formyl folates, involved in purine synthesis, were raised 30-fold after 26 hours of incubation followed by DNA synthesis, indicatmg that folate synthesis precedes nucleotide synthesis channelising the one-carbon moieties into nucleotide precursors. This is also supported by the observation of folate mediated one-carbon pool incorporation of 2-'4C-Histidine into nucleic acid during this period. The two folate enzymes, folylpolyglutamate hydrolase which was greatly lowered and folylpolyglutamate synthetase which was significantly elevated, might playa crucial role regulating a balanced supply of the required folate precursors during the early germination period of Vigna radiata.

Nested polymerase chain reaction in the diagnosis of congenital cytomegalovirus infection

OBJECTIVE

Human cytomegalovirus infection is highly prevalent in Indian population. It is the commonest congenitally acquired infection causing various anomalies. The diagnosis of infection in neonates is difficult as IgM may not be detected in all cases. The polymerase chain reaction is reported as alternative and better option in these patients. However, there is lack of data to substantiate this preference in a resource poor country like India.

METHODS

Blood samples from 930 neonates/fetuses were first tested for specific anti-CMV IgM antibodies using mu-capture enzyme linked immunosorbent assay, Mac-ELISA. Nested PCR was first standardised on clinically and therapeutically confirmed cases of CMV disease. In the second phase blood samples randomly from 20 babies suspected of CMV infection were collected for serology and PCR and both tests were run independently. Twenty healthy controls were also included. IgM ELISA and PCR were performed on these samples and results of these 20 samples were compared to evaluate the sensitivity and specificity of each method.

RESULTS

Out of 930 serum samples of suspected congenital CMV infection 188 (20.2%) were found positive for CMV specific IgM antibodies. While comparing the results of 40 paired samples, PCR was found to be highly specific (100%) but less sensitive than Mac-ELISA (95%) with negative predictive value of 100% and positive predictive value of 95%. Thus in congenital CMV infection Mac-ELISA was less costly, less cumbersome and more user friendly.

CONCLUSION

The Mac-ELISA seem to have parallel sensitivity and specificity as PCR for diagnosing congenital CMV infection.

The acute effect of calcium carbonate on the intestinal absorption of levothyroxine

To determine the acute effect of calcium, we measured levothyroxine absorption after ingestion of thyroxine (T4) with and without simultaneous ingestion of calcium (as calcium carbonate) in seven volunteers without thyroid disease. Serum total T4, total triiodothyronine (T3), free T4, and thyrotropin (TSH) levels were measured after ingestion of 1,000 microg of levothyroxine on two separate visits at 4-week intervals: (1) levothyroxine alone and (2) levothyroxine together with 2.0 g of calcium as calcium carbonate. The amount of absorbed levothyroxine was calculated as the incremental rise in serum T4 level during the first 6 hours multiplied by the volume of distribution for the hormone. When 1,000 microg of levothyroxine alone was given to subjects, the maximum average total T4 absorption was 837 microg (83.7% of the dose ingested) at 120 minutes. When levothyroxine was coadministered with 2.0 g of calcium (as calcium carbonate), the maximum average T4 absorption decreased to 579 microg (57.9% of the dose ingested) at 240 minutes. The total levothyroxine absorption over 6 hours was significantly greater with thyroxine than that with thyroxine and calcium (p = 0.02). The administration of calcium and levothyroxine in these subjects was associated with a significant reduction in the peak increment in serum total T4 (p = 0.02) and free T4 levels (p = 0.03), as well as a significant reduction in the overall increment in serum total T4 (p = 0.003), free T4 (p = 0.002), and total T3 levels (p = 0.01) over four time points (120 minutes, 240 minutes, 360 minutes, 1,440 minutes). In summary, this pharmacokinetic study in seven volunteers indicates that calcium carbonate acutely reduces T4 absorption.

Prognostic value of serum cardiac troponin I in ambulatory patients with chronic renal failure undergoing long-term hemodialysis: a two-year outcome analysis

OBJECTIVES

We sought to evaluate the prognostic value of cardiac troponin I (cTnI) in asymptomatic, ambulatory patients with chronic renal failure treated with long-term hemodialysis.

BACKGROUND

Smaller, short-term follow-up studies on this subject have given conflicting results.

METHODS

A total of 126 ambulatory patients with chronic renal failure treated with long-term hemodialysis were followed for two years for all-cause mortality, cardiac mortality, all-cause hospital admissions and cardiac hospital admissions. Serum cTnI was measured before dialysis at the time of study entry.

RESULTS

One hundred two patients had normal serum levels of cTnI (< or =0.03 ng/ml) and 24 patients had elevated levels (0.015 +/- 0.007 vs. 0.053 +/- 0.029 ng/ml, p < 0.0001). No significant difference in all-cause mortality (20 vs. 4 deaths), cardiac mortality (4 vs. 1 death), all-cause hospital admissions (1.74 +/- 1.72 vs. 1.25 +/- 1.19 admissions/patient) or cardiac admissions (0.52 +/- 0.89 vs. 0.33 +/- 0.76 admissions/patient) was present between the patients with normal cTnI levels and those with elevated cTnI levels. Serum cTnI was not significantly different between patients who died versus those who survived (0.022 +/- 0.019 vs. 0.022 +/- 0.021 ng/ml). Serum cTnI was not an independent predictor of all-cause mortality, cardiac mortality, all-cause admissions or cardiac admissions. Age (older) and serum albumin (lower) were independent predictors of all-cause mortality, whereas a history of myocardial infarction was an independent predictor of cardiac mortality. Serum sodium (lower) was an independent predictor of all-cause hospital admissions, whereas hypertension and previous myocardial infarction were independent predictors of cardiac admissions. The best predictors of the time to death were age (older) and serum sodium level (lower), irrespective of the serum cTnI levels.

CONCLUSIONS

Cardiac troponin I has a limited role in predicting mortality and hospital admissions in asymptomatic patients with chronic renal failure treated with long-term hemodialysis.

Effect of defects on thermal denaturation of DNA oligomers

Effect of defects on the melting profile of short heterogeneous DNA chains is calculated using the Peyrard-Bishop Hamiltonian. On-site potential on a defect site is represented by a potential that has only a short-range repulsion and a flat part without well of the Morse potential. Stacking energy between two neigbouring pairs involving a defect site is also modified. The results are found to be in good agreement with the experiments.

Seasonal pattern of early mortality and infectious complications in liver transplant recipients

Seasonal variation has been documented in the frequency and attributable mortality of a number of medical illnesses and infections in the nontransplantation setting. Whether similar trends exist in transplant recipients is not known. Seasonal rates of overall and early mortality and contributory variables stratified by season were assessed in 190 consecutive liver transplant recipients who underwent transplantation over a 10-year period. The frequency of infectious complications and rejection was also assessed and stratified by season of transplantation. Early (deaths occurring in the first year posttransplantation), but not overall, mortality correlated significantly with seasonality. Of patients with early mortality, 43% (13 of 30 patients) died in winter; 23% (7 of 30 patients), in spring; 13% (4 of 30 patients), in summer; and 20% (6 of 30 patients), in fall. The frequency of deaths in winter was significantly greater than for all other seasons (P = .022). The high wintertime mortality could not be explained by previously recognized risk factors portending a poor outcome, e.g., United Network for Organ Sharing status, Child-Pugh score, surgical time, blood loss, pretransplantation and posttransplantation dialysis, infections, rejection, or increased immunosuppression. Strong trends toward a higher rate of cytomegalovirus disease in patients who underwent transplantation in fall (P = .09) and bacterial infections in those who underwent transplantation in winter were documented (P = .09). There was no correlation between seasonality and rejection. Early mortality in winter in liver transplant recipients was significantly greater than if the deaths were totally random. Whether the seasonal clustering of deaths and infections is triggered by respiratory viruses, yet unrecognized viruses, or unknown exogenous factors remains to be determined.

Nutritional status of adolescent girls of a slum community of Varanasi

In order to assess nutritional status of adolescent girls of a slum community of Varanasi and factors influencing them, this study was carried out on 70 girls belonging to the age group 13 to 18 years. The study subjects were selected from Sunderpur, an urban community of Varanasi, by adopting appropriate sampling methodology. The approach adopted for the study was a cross sectional one. The tools in the study were pre-designed and pre-tested schedule, weighing scale, steel anthoropometric rod and measuring tape. The techniques of the study included interview method, clinical examination and anthropometry. In all, 70.0% adolescent girls had BMI < 20%; 51.43% study subjects were suffering from Chronic Energy Deficiency (CED). Stunting (Height for age alpha 90%) was present in 10% of adolescent girls. Their average Weight, Height, MAC were 83.45%, 93.08% and 82.05% of the corresponding estimated reference values. Significant association of common parameters (viz., age, caste, income, type of family, working and literacy status) with nutritional status of study subjects was not observed in this study. However, lesser undernutrition in large families (> 6) indicated role of familial support in prevention of undernutrition in adolescent girls.

Efficient presentation of both cytosolic and endogenous transmembrane protein antigens on MHC class II is dependent on cytoplasmic proteolysis

Peptides from extracellular proteins presented on MHC class II are mostly generated and loaded in endolysosomal compartments, but the major pathways responsible for loading peptides from APC-endogenous sources on MHC class II are as yet unclear. In this study, we show that MHC class II molecules present peptides from proteins such as OVA or conalbumin introduced into the cytoplasm by hyperosmotic pinosome lysis, with efficiencies comparable to their presentation via extracellular fluid-phase endocytosis. This cytosolic presentation pathway is sensitive to proteasomal inhibitors, whereas the presentation of exogenous Ags taken up by endocytosis is not. Inhibitors of nonproteasomal cytosolic proteases can also inhibit MHC class II-restricted presentation of cytosolically delivered protein, without inhibiting MHC class I-restricted presentation from the same protein. Cytosolic processing of a soluble fusion protein containing the peptide epitope I-Ealpha(52-68) yields an epitope that is similar to the one generated during constitutive presentation of I-Ealpha as an endogenous transmembrane protein, but is subtly different from the one generated in the exogenous pathway. Constitutive MHC class II-mediated presentation of the endogenous transmembrane protein I-Ealpha is also specifically inhibited over time by inhibitors of cytosolic proteolysis. Thus, Ag processing in the cytoplasm appears to be essential for the efficient presentation of endogenous proteins, even transmembrane ones, on MHC class II, and the proteolytic pathways involved may differ from those used for MHC class I-mediated presentation.

Factors affecting quality of life in patients with HIV infection

Given the longevity achievable with current prophylactic and therapeutic strategies for persons with HIV infection, quality of life (QOL) has emerged as a significant medical outcome measure, and its enhancement as an important goal. This review highlights current knowledge about the relevance and complexity of physical, psychological, and social factors as determinants of health-related quality of life (HRQOL) in HIV-infected persons. Existing data suggest physical manifestations, antiretroviral therapy, psychological well-being, social support systems, coping strategies, spiritual well-being, and psychiatric comorbidities are important predictors of QOL in this population. Health care professionals are encouraged to become familiar with the full spectrum of predictors of HRQOL, which may eventually contribute to the development of multiple entry points for interventions in promoting QOL in these patients. Identifying variables influencing QOL among diverse groups, particularly women, injection drug users, and adolescents, and designing effective interventions specific to the social and psychological well-being of HIV-infected individuals are areas for research.

Fine needle aspiration cytology of sclerosing lobular hyperplasia of the breast: a case report

BACKGROUND

Sclerosing lobular hyperplasia presenting as a palpable, circumscribed nodular mass in a young female's breast is characterized histologically by prominent hyperplasia of the lobules and sclerosis of the intralobular connective tissue. The cytomorphologic features and differential diagnosis of the lesion are presented.

CASE

A 14-year-old female presented with a painless, progressively increasing, nodular, firm, mobile lump measuring 5 x 5 cm in the right breast. The clinical and radiologic diagnosis was fibroadenoma. Fine needle aspiration smears showed a clean background with uniform, round to oval epithelial cells in flat sheets, round clusters and rosettelike (acinar) arrangements. A few naked nuclei were present, while stromal fragments were not seen.

CONCLUSION

When analyzed in the context of the clinical findings, the cytologic features of sclerosing lobular hyperplasia help to differentiate it from other benign palpable nodular lesions of the juvenile breast.

The natural killer T-cell ligand alpha-galactosylceramide prevents autoimmune diabetes in non-obese diabetic mice

Diabetes in non-obese diabetic (NOD) mice is mediated by pathogenic T-helper type 1 (Th1) cells that arise because of a deficiency in regulatory or suppressor T cells. V alpha 14-J alpha 15 natural killer T (NKT) cells recognize lipid antigens presented by the major histocompatibility complex class I-like protein CD1d (refs. 3,4). We have previously shown that in vivo activation of V alpha 14 NKT cells by alpha-galactosylceramide (alpha-GalCer) and CD1d potentiates Th2-mediated adaptive immune responses. Here we show that alpha-GalCer prevents development of diabetes in wild-type but not CD1d-deficient NOD mice. Disease prevention correlated with the ability of alpha-GalCer to suppress interferon-gamma but not interleukin-4 production by NKT cells, to increase serum immunoglobulin E levels, and to promote the generation of islet autoantigen-specific Th2 cells. Because alpha-GalCer recognition by NKT cells is conserved among mice and humans, these findings indicate that alpha-GalCer might be useful for therapeutic intervention in human diseases characterized by Th1-mediated pathology such as Type 1 diabetes.

A comparative study of telomerase activity in sputum, bronchial washing and biopsy specimens of lung cancer

The potential of telomerase, the ribonucleoprotein enzyme, as a non-invasive screening marker was studied in pre-bronchoscopy sputum (S), bronchial washings (W) and bronchoscopic biopsy (B) samples from individuals under evaluation for lung cancer. Out of the 52 cases studied, 42 were clinically suspected primary lung cancer patients and 10 had pulmonary disorders but had no clinical evidence of lung cancer. Fifteen (39.5%) S samples, 24 (63.1%) W samples and 32 (84.2%) B samples, which were cytologically/histopathologically positive were also positive for telomerase activity. Interestingly, 16 (42%) S samples, 20 (52.6%) W samples and 20 (52.6%) B samples, initially reported cytologically/histopathologically negative, showed detectable telomerase activity. Lung cancer was finally confirmed in these cases by repeat cytology/histopathology. However, telomerase activity was detected in 31 (81.6%) S, 26 (68.4%) W and 33 (86.8%) B samples of suspected lung cancer patients. Telomerase activity was negative in S, W, and B of four of the suspected cases, which ultimately turned out to be negative for lung cancer. Cytopathology/histopathology alone (including repeat attempts) identified 15 (39.5%) cases of sputum, 24 (63.1%) cases of bronchial washings and 32 (84.2%) bronchoscopic biopsy samples. Out of 10 controls, low telomerase activity was detected in only one (10%) of the bronchial washings, which later turned out to be due to large number of inflammatory cells. Telomerase activity assay of sputum carried sensitivity, specificity and diagnostic accuracy of 81.6, 100 and 86.5%, respectively, while that for bronchial washing was 68.4, 100 and 76.9%, respectively, and for bronchoscopic biopsy samples was 86.8, 100 and 88.1%, respectively. A positive correlation (P<0.01) was seen between age and telomerase activity in sputum, bronchial washing and biopsy samples but no significant correlation was seen between sex and telomerase activity or duration of smoking and telomerase activity. A significant positive correlation was observed between staging and telomerase activity in sputum (P<0.01), bronchial washing (P<0.01) and biopsy samples (P<0.01). Our findings indicate that telomerase is a specific marker for malignant lung disease and can complement cytology/histopathology in the diagnosis of lung cancer. Sputum telomerase assay holds the potential for early and non-invasive diagnosis of lung cancer.

A multicentric study with arteether in patients of uncomplicated falciparum malaria

Two hundred and sixty seven patients of uncomplicated P. falciparum malaria completed study in a multicentric phase III clinical trial of Arteether. Arteether was given intramuscularly in a dose of 150 mg daily for three consecutive days. Each patient was followed upto 28 days of alpha, beta arteether therapy. The cure rate was 97% with fever clearance time between 1-7 days (24-168 hours) and parasite clearance time between 1-3 days (24-72 hours). Parasite reappearance rate was found to be 3% and reported at only three of the centres. Following the treatment no adverse effect was observed on haematological, biochemical and vital clinical parameters.

Control of an outbreak of infection due to extended-spectrum beta-lactamase--producing Escherichia coli in a liver transplantation unit

We report an outbreak of infection due to genotypically identical extended-spectrum beta-lactamase--producing Escherichia coli among patients in a liver transplantation unit. Control of the outbreak was achieved by a combination of contact isolation, feedback on hand hygiene, and gut decontamination with an orally administered fluoroquinolone. These interventions led to abrupt curtailment of the outbreak.

Dyslipidaemia in HIV-infected patients: association with adherence to potent antiretroviral therapy

Metabolic complications are being increasingly recognized among HIV-infected patients treated with potent combination antiretroviral therapies. We sought to assess the association of dyslipidaemia with adherence to protease inhibitor (PI) therapy and with the markers of clinical response to antiretroviral therapy (CD4 count, HIV RNA viral level) through a prospective, cross-sectional cohort study. Fifty-six HIV-infected patients who were already on, or who were started on PI-containing antiretroviral therapy were monitored for the development of dyslipidaemias. Therapy with PI-containing antiretroviral therapy was significantly associated with elevated serum triglyceride level (>250 mg/dl) (52% vs 8%, P=0.001). Patients with an adherence rate of at least 80% to a PI-containing regimen were significantly more likely to have elevated low density lipoprotein (LDL) cholesterol level as compared to patients with an adherence rate of <80% (79% vs 26%, P=0.03). Patients with an adherence rate of at least 80% to a PI-containing regimen were also significantly more likely to have severe hypertriglyceridaemia (>800 mg/dl) as compared to patients with an adherence rate of <80% (21% vs 4%, P=0.04). Viral load at the last study visit did not correlate with total cholesterol (r=-0.39, P=0.30), LDL cholesterol (r=0.57, P=0.30), or triglyceride level (r=0.55, P=0.20). However, there was a significant correlation between the last viral load and high density lipoprotein (HDL) cholesterol (r=0.79, P=0.035), i.e. lower viral load was associated with higher HDL cholesterol level. In conclusion, dyslipidaemia in patients with HIV infection was significantly associated with adherence to PI-containing antiretroviral therapy. Patients who are adherent to PI-containing regimens at least 80% of the time warrant close monitoring for the development of dyslipidaemia.

Sorption behavior of metolachlor, isoproturon, and terbuthylazine in soils

The sorption-desorption of metolachlor [2-chloro-N-(ethyl-6-methyl phenyl)-N-(2-methoxy-1-methyl ethyl) acetamide], isoproturon [3-(4-isopropyl phenyl)-1,1-dimethyl urea] and terbuthylazine [N6-tert butyl-6-chloro-N4-ethyl-1,3,5-triazine-2,4-diamine] herbicides was studied in two German soils at 1:10 soil to water ratio by batch method. Equilibrium of herbicides between soil and water (0.01 M CaCl2) was attained in 2 h. Sorption data fitted very well to Freundlich equation, represented by very high correlation coefficient (r2 > 0.934). Comparison of Freundlich K values indicated that sorption of all the three herbicides was most pronounced in soil having higher organic carbon content. Koc values were as expected nearly identical for each herbicide in the two soils. The Freundlich constant (1/n) was about 1 for metolachlor and less than 1 for terbuthylazine and isoproturon indicating a L-type of sorption isotherms. Desorption of all the three herbicides showed hysteresis. Nearly equal amounts of metolachlor, isoproturon and terbuthylazine were desorbed from both soils. There was a good correlation between Koc and solubility.

Cocaine-induced torsades de pointes in idiopathic long Q-T syndrome

Torsades de pointes is a ventricular tachycardia characterized by the QRS complexes of changing amplitude that appear to twist around an isoelectric line. It usually precipitates in the setting of underlying Q-T interval prolongation, which has both congenital and acquired causes. The common acquired causes of torsades precipitation are medications, electrolyte imbalance, and severe bradycardia. This report presents a case of torsades de pointes that was precipitated by substance abuse in a patient with idiopathic long Q-T syndrome and required several treatment modalities.

Epidemiological study of congenital heart disease

A community based survey of congenital heart disease was carried out on a random sample of 11,833 children below 15 years in Delhi, India. Congenital heart disease was diagnosed on clinical history and/or clinical examination. Out of the examined sample, 50 were found suffering from congenital heart disease, giving an overall prevalence of 4.2/1000 (4.6/1000 in boys and 3.7/1000 in girls). The prevalence rate was slightly higher than other studies carried out in the country. The reason is obvious. The present study is community based while other studies were hospital or school based. The type of lesions were similar to those reported from other studies. The lesions in order of frequency were ventricular septal defect (46%), atrial septal defect (18%), patent ductus arteriosus (14%), Fallot's tetrology (10%), aortic stenosis (4%), and pulmonary stenosis (4%). Like other studies ventricular septal defect was the commonest lesion. The prevalence rate was higher in the age group 0-4 years and 5-9 years in boys whereas it was higher in adolescent age group (10-14 years) in girls.

Surgical extirpation of a chest wall desmoid tumor: a case report

A case is described of an anterior chest wall desmoid tumor in a 20-year-old Micronesian male that had been previously incompletely resected one year prior to presentation. A radical chest wall resection was performed with reconstruction accomplished using a gortex patch and latissimus dorsi myocutaneous flap. The patient developed a massive local recurrence within eight months following surgery. This report illustrates the local aggressiveness of these benign tumors. A historical perspective, etiology, and treatment principles are discussed.