Death after cardiac transplantation in low birth weight neonates.
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Biomedical subjects
Publications and source records attributed to T Singh.
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Pseudomonas fluorescens strains (LAM1-hydrophilic) and (LAM2-hydrophobic) showed positive chemotaxis towards attractants (sugars, amino acids, polyols and organic acids) present in the exudate of Macrophomina phaseolina (a soil-borne plant pathogenic fungus). The varied response of motility traits such as speed, rate of change in direction (RCDI) and net to gross displacement ratio (NGDR) was observed for different chemoattractants. Swimming speed of the strains was highest in 10-fold diluted exudate or 100-1000 microM strength of different attractants, but further dilutions significantly decreased the swimming speed (P = 0.05). Chemotactic response of P fluorescens was positively correlated with swimming speed (P = 0.05; r = 0.76). Relative to control, the RCDI values decreased 1.5-fold in amino acids or sugars, and 1.2-fold in polyols or organic acids. With increase in swimming speed, the NGDR of both strains also increased, but the RCDI decreased. Both hydrophilic and hydrophobic strains did not show significant differences in their motility traits. The results demonstrate that M. phaseolina exudate contains chemical attractants that serve as signal for flagellar motility of P. fluorescens. Motile P fluorescens strains thus may consume fungal exudate as nutrients, and thus spores could offer a niche for these bacteria in soil.
A large number of children suffer from behavioral problems during their development. Many of these problems are transient and may not even be noticed. At times, however, the extent of these problems and their overall effects on a child's development can be serious (Morita et al., 1993). Further, children may exhibit these behaviors in one setting and not in others (e.g. at home or in school, but not both). In developed countries, parents tend to seek advice for even minor problems, such as persistent thumb sucking, while in developing countries, major problems, even childhood schizophrenia, may go unattended. An awareness of the prevalence of these problems is important so that appropriate mental health services can be planned and provided for affected children, to improve their prospects for leading healthy, productive lives. Such awareness can help enhance the teaching of graduate doctors, equipping them to deal with these problems effectively.
BACKGROUND: New York City (NYC) pediatricians are now caring for fewer HIV-infected infants and more school age children and adolescents than earlier in the epidemic. METHODS: Clinical, laboratory and demographic data were abstracted from medical records at 10 NYC centers participating in the CDC Pediatric Spectrum of HIV Disease project. Pediatric AIDS cases and HIV-related deaths reported to the NYC Department of Health were examined. RESULTS: Median age of HIV-infected children in care increased from 3 years in 1989 to 1991 to 6 years in 1995 to 1998. The number of HIV-infected women giving birth in NYC declined 50% from 1990 to 1997 (1630 to 831); increasing numbers were identified prenatally (14% in 1989; 78% after 1995); and most received prenatal zidovudine prophylaxis (73% in 1997). Estimated perinatal transmission decreased to 10% by 1997. Improved identification of seropositive status in infants was associated with an increased proportion of infected infants receiving Pneumocystis carinii pneumonia (PCP) prophylaxis, 84% in 1997. AIDS free survival was longer for children born 1995 to 1998 than for those born before 1995, P = 0.004. In 1998 among children with advanced immunosuppression (CDC category 3), 66% were prescribed 3 or more antiretroviral medicines and 88% received PCP prophylaxis. Citywide AIDS cases and HIV-related deaths fell precipitously beginning in 1996. CONCLUSIONS: Based on the observations of this study, the cohort of NYC HIV-infected children in care is aging, associated with a decline in new HIV infections, high rates of PCP prophylaxis and increased time to AIDS. Falling HIV-related deaths citywide support these observations.
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Sentinel lymph node (SLN) mapping accurately diagnoses the status of nodal basin with >95% accuracy in melanoma and breast cancer. A multicenter trial for SLN mapping was performed on 203 patients with colorectal cancer to determine accuracy, upstaging, skip metastasis, and aberrant drainage. Lymphazurin 1% was injected subserosally around the tumor and 1-4 blue staining nodes were marked as SLNs for detailed histological analysis. SLN mapping was successful in 98% of patients with an average of 1.7 SLNs per patient. SLNs were negative in 63% of the patients and positive in 37% of the patients. Skip metastasis was seen in 8 of the patients. Occult micrometastasis was found in 14% of patients. In 5% of the patients, unusual lymphatic drainage lead to an alteration of the extent of lymphadenectomy. This multicenter trial proved that SLN mapping in patients with colorectal cancer is simple, cost effective, and upstages at least 14% of patients from AJCC stage I/II to stage III. These patients may then benefit from adjuvant chemotherapy.
AIM: The present study was designed to analyse clinical, haematological and histomorphogical features in 37 cases of myelodysplasic syndrome (MDS). MATERIAL AND METHODS: FAB criteria was used to diagnose MDS in 37 patients. Clinical details, peripheral blood findings, bone marrow aspirate and biopsy were reviewed. RESULTS: Of 37 cases, there were 25 females and 12 males in age range of 2 years to 75 years. There were three children. There were nine cases of refractory anaemia (RA), 18 of refractory anaemia with excess blasts (RAEB), nine of refractory anaemia with excess blasts in transformation (RAEB-t) and one of chronic myelomonocytic leukemia (CMML). All were denovo MDS. All patients had pallor. Hepato and/or splenomegaly was seen in 15 cases. Anemia, leukopenia and thrombocytopenia was seen in 37, 6 and 23 cases respectively. Bone marrow aspiration (BMA) was hyper to normo cellular in 35 cases. Dyshemopoiesis was seen in one or more cell lines in all cases. Bone marrow biopsy (BMB) was available in 16 cases. Abnormal localisation of immature precursors (ALIP) was seen in 11/12 biopsies of RAEB and 3/4 of RAEB-t. BMB was helpful in diagnosis of 3 doubtful cases (one RAEB and two RAEB-t), and upgrading of 2 cases of RAEB to RAEB-t. On follow up, 1 case of RA, 3 of RAEB, 1 of RAEB-t developed AML. One case of RAEB developed ALL and 2 progressed to RAEB-t. CONCLUSION: Primary MDS is seen in all age groups. Pallor is commonest presentation. RAEB was commonest subgroup seen. BMB is helpful in diagnosis of doubtful cases. ALIP is a reliable diagnostic feature of MDS. BMB is a diagnostic as well as prognostic tool in MDS cases which should be taken as a mandatory investigation.
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BACKGROUND: Sentinel lymph node (SLN) mapping for melanoma and breast cancer has greatly enhanced the identification of micrometastases in many patients, thereby upstaging a subset of these patients. The purpose of this study was to see if SLN mapping technique could be used to identify SLNs in colorectal cancer and to assess its impact on pathological staging and treatment. METHODS: At the time of surgery, 1 ml of Lymphazurin 1% was injected subserosally around the tumor without injecting into the lumen. The first to fourth blue nodes identified were considered the SLNs, which have the highest probability to contain metastases. A standard oncological resection of the bowel was then performed. Multilevel microsections of the SLNs, including a detailed pathological examination of the entire specimen, was performed. RESULTS: SLN was successfully identified in 85 (98.8%) of 86 patients. In 85 patients, there were 1,367 (16 per patient) lymph nodes examined, of which 140 (1.6 per patient) were identified as SLNs. In 53 (95%) of 56, of whom the SLNs were without metastases (negative), all other non-SLNs also were negative. In 29 (34% of 85) patients, SLNs were positive for metastases; in 14 of the 29 patients, other non-SLNs also were positive in addition to the SLNs. In the other 15 of the 29 patients (18% of 85 patients), SLNs were the only site of metastases, and all other non-SLNs were negative. In 7 patients (8.2% of 85 patients), micrometastases were identified only in 1 or 2 of the 10 sections of a single SLN. In five of seven patients, such micrometastases were detected by hematoxylin and eosin staining and immunohistochemistry; in the other two patients, it was detected only by immunohistochemistry. In patients with negative SLNs, the rate of occurrence of micrometastases in non-SLNs was 5 (0.4%) of 1,184 lymph nodes. CONCLUSIONS: SLN mapping can be performed easily in colorectal cancer patients, with an accuracy of more than 95%. The identification of submicroscopic lymph node metastases by this technique may have upstaged these patients (18%) from stage I/II to stage III disease, who may then benefit from further adjuvant chemotherapy.
Ziconotide is a selective peptide antagonist of the N-type calcium channel currently in clinical trials for analgesia. Ziconotide reached a maximal brain concentration of between 0.003 and 0.006% of the injected material per gram of tissue at 3-20 min after i.v. injection, and this decayed to below 0.001%/g after 2 h. The structurally distinct conopeptide SNX-185 (synthetic TVIA) was considerably more persistent in brain after i.v. administration, with 0.0035% of the injected material present at 2-4 h after i.v. injection, and 0.0015% present at 24 h. Similar results (i.e. greater persistence of SNX-185) were obtained when the peptides were perfused through in vivo dialysis probes implanted into the hippocampus. Image analysis and serial sectioning showed that diffusion of Ziconotide in the extracellular fluid around the dialysis probe was minimal, with the peptide located within 1 mm of the probe after 2 h. In vitro diffusion through cultured bovine brain microvessel endothelial cells (BBMEC) verified that a close structural analog of Ziconotide (SNX-194) passed through this blood-brain barrier (BBB) model as expected for peptides of similar physical properties (permeability coefficient of 6.5 x 10(-4) cm/g). Passage from blood to brain was also verified by in situ perfusion through the carotid artery. A statistically greater amount of radioactivity was found to cross the BBB after perfusion of radioiodinated Ziconotide compared to [14C]inulin. Capillary depletion experiments and HPLC analysis defined the brain location and stability.
OBJECTIVE: To test whether or not endotoxin induces a dose-dependent reduction of myocardial contractile dysfunction after a standardized period of myocardial ischemia and reperfusion and whether nitric oxide is involved in this form of myocardial protection. DESIGN: Prospective, randomized, controlled animal study. SETTING: University research laboratory. SUBJECTS: Twenty-five male Sprague-Dawley rats. INTERVENTIONS: After anesthesia, the left carotid artery was cannulated under sterile conditions and animals were allowed to recover from surgery for 12 hrs. Sterile saline or increasing doses (2.5, 5, or 10 mg/kg body weight) of endotoxin (Escherichia coli O26:B6; Sigma, Mississauga, Ontario, Canada) were given intravenously (1 mL over 5 mins). In some rats, diaspirin-crosslinked hemoglobin (200 mg/kg) was infused 6 hrs and 60 min before endotoxin infusion (10 mg/kg). Hearts were rapidly excised for retrograde perfusion through the ascending aorta (Langendorff apparatus) 6 hrs later. After baseline data collection, hearts were subjected to global ischemia (30 mins, 37 degrees C [98.6 degrees F]), followed by 30 mins of reperfusion. MEASUREMENTS AND MAIN RESULTS: Physiologic variables were recorded 6 hrs after saline and endotoxin infusion. Baseline myocardial systolic contractility and diastolic compliance were assessed, respectively, by left ventricular developed pressure (LVDP) and left ventricular (LV) volume-preload relationships. After 30 min of reperfusion, LVDP recovery and left ventricular end-diastolic pressure were measured. Endotoxin induced LV systolic contractile depression, irrespective of the dose of endotoxin administered. LV diastolic dysfunction varied between different doses of endotoxin administered. On reperfusion, endotoxin produced a dose-dependent improvement of postischemic LVDP recovery: 30+/-6% in sham, 78+/-9% in 2.5 mg/kg, 93+/-8% in 5 mg/kg, and 107+/-10% in 10 mg/kg endotoxin heart. In rats treated with 10 mg/kg endotoxin, diaspirin-crosslinked hemoglobin pretreatment abrogated endotoxin-induced postischemic LVDP recovery improvement (105+/-10% vs. 43+/-7%, p = .01). CONCLUSION: Sublethal doses of endotoxin induce in a dose-dependent manner a delayed form of myocardial protection against ischemia. Although free-cell hemoglobin solution abrogates this endotoxin-induced cross-tolerance, we propose that possible mechanisms involved in this form of myocardial protection include nitric oxide pathway activation.
BACKGROUND: A study was undertaken to establish the chronic effect of initial and recurrent treated pulmonary tuberculosis on impairment of lung function. METHODS: A total of 27 660 black South African gold miners who had reliable pulmonary function tests from January 1995 to August 1996 were retrospectively followed for the incidence of pulmonary tuberculosis to 1970. The lung function measurements in 1995-6 were related to the number of previous episodes of tuberculosis and to the time that had lapsed from the diagnosis of the last episode of tuberculosis to the lung function test. Miners without tuberculosis or pneumoconiosis served as a comparison group. RESULTS: There were 2137 miners who had one episode of tuberculosis, 366 who had two, and 96 who had three or more episodes. The average time between the diagnosis of the last episode of tuberculosis and the lung function test was 4.6 years (range one month to 31 years). The loss of lung function was highest within six months of the diagnosis of tuberculosis and stabilised after 12 months when the loss was considered to be chronic. The estimated average chronic deficit in forced expiratory volume in one second (FEV(1)) after one, two, and three or more episodes of tuberculosis was 153 ml, 326 ml, and 410 ml, respectively. The corresponding deficits for forced vital capacity (FVC) were 96 ml, 286 ml, and 345 ml. The loss of function due to tuberculosis was not biased by the presence of HIV as HIV positive and HIV negative subjects had similar losses. The percentage of subjects with chronic airflow impairment (FEV(1) <80% predicted) was 18.4% in those with one episode, 27.1% in those with two, and 35.2% in those with three or more episodes of tuberculosis. CONCLUSIONS: Tuberculosis can cause chronic impairment of lung function which increases incrementally with the number of episodes of tuberculosis. Clearly, prevention of tuberculosis and its effect on lung function is important and can be achieved by early detection and by reduction of the risk of tuberculosis through intervention on risk factors such as HIV, silica dust exposure, silicosis, and socioeconomic factors.
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Thirty-five patients admitted with psychosis either immediately or within six months of delivery were analysed for various risk factors. Primiparity, previous psychiatric history, antenatal complications, caesarean section, perinatal death and female baby were all associated with an increased risk of psychiatric admission, suggesting that psychological stresses do contribute to high psychiatric morbidity in puerperium. Women with history of affective disorder had a much higher risk of psychiatric admissions in the puerperium than those with history of schizophrenia or depressive neurosis.
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BACKGROUND: New York City has only 3% of the U.S. population but has reported nearly 16% of all AIDS cases. METHODS: This is an observational study using the New York City vital events and AIDS case surveillance registries to describe trends in HIV/AIDS mortality from 1983 through June 30, 1998. RESULTS: Annual HIV/AIDS deaths increased steadily until stabilizing at 7046 in 1995, declined 29% to 4998 in 1996, and declined 47% to 2625 in 1997. Comparing data from 1997 with those from 1995, declines occurred in all demographic groups and in all major HIV transmission categories: 74% in men who have sex with men, 68% in injecting drug users, and 64% in heterosexuals. In the first 6 months of 1998, declines were smaller than they had been in previous 6-month intervals in all demographic groups except Hispanic males and those between 35 and 44 years of age. From 1995 to the first 6 months of 1998, the number of people living with AIDS in New York City increased 22% (from 32,692 to 39,976). CONCLUSIONS: The precipitous 63% decline in HIV/AIDS deaths from 1995 to 1997 occurred at the same time that more effective antiretroviral therapies became widely available. The slowing in the mortality decline observed in 1998, however, suggests that although these new therapies may have a profound effect at the population level, deaths due to AIDS will continue.
The crystal structure of the ribosome-inactivating protein (RIP) mistletoe lectin I (ML-I) from Viscum album has been solved by molecular replacement techniques. The structure has been refined to a crystallographic R-factor of 24.5% using X-ray diffraction data to 2.8 A resolution. The heterodimeric 63-kDa protein consists of a toxic A subunit which exhibits RNA-glycosidase activity and a galactose-specific lectin B subunit. The overall protein fold is similar to that of ricin from Ricinus communis; however, unlike ricin, ML-I is already medically applied as a component of a commercially available misteltoe extract with immunostimulating potency and for the treatment of human cancer. The three-dimensional structure reported here revealed structural details of this pharmaceutically important protein. The comparison to the structure of ricin gives more insights into the functional mechanism of this protein, provides structural details for further protein engineering studies, and may lead to the development of more effective therapeutic RIPs.
Human cytomegalovirus (CMV) infection can be life threatening in the immune compromised and is associated with congenital defects and / or mental retardation in the neonate. The demonstrated association between CMV infection and rheumatoid factor (RF) raised the possibility of an induction of an autoimmune response upon vaccination with a candidate CMV vaccine, glycoprotein gB (UL55). The antibody responses generated after injections of an adenovirus-gB construct (Ad-gB) were studied in autoimmune-prone (MRL/mpj) and normal (BALB.k, C3H, and BALB/c) mice. Enzyme-linked immunosorbent assay and immunoblot analyses were done to identify the autoantibodies produced following immunization. Immunization with Ad-gB induced a significant IgG anti-viral response in all strains tested (p < 0.0001) compared to phosphate-buffered saline or HeLa controls. Ad-gB induced a significant IgG autoantibody response (p > 0.005) to the U1-70 kDa spliceosome protein in both autoimmune and normal strains whereas immunization with recombinant human La/SS-B did not. Autoantibodies to U1-70 kDa are part of the anti-ribonucleoprotein response seen in systemic lupus erythematosus and mixed connective tissue disease. Low levels of IgG RF and anti-double-stranded DNA antibodies were also induced. This study raises concern that immunization with CMV gB in individuals genetically predisposed to autoimmunity could trigger the development or acceleration of an autoimmune disease.