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Biomedical subjects

A Sen

Publications and source records attributed to A Sen.

At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

Growth phase and metal-dependent regulation of the dpsA gene in Synechococcus sp. strain PCC 7942, USA.

The Synechococcus sp. strain PCC 7942 dpsA gene encodes a stress-inducible DNA-binding protein whose transcription increases in the stationary phase. Such transcription is likely under the control of an alternative sigma factor. Our current work indicated that dpsA transcription is also important under metal-ion limitation, because dpsA mRNA levels increased 12-fold under low-iron conditions, and that dpsA function is essential for growth under iron-limiting conditions. Promoter activity of the dpsA-promoter-lacZ reporter gene constructs implied that a region of dyad symmetry centered 28 nucleotides from the transcription start is required for metal-dependent repression, as judged by the level of lacZ induction following treatment of cultures with the chelator 2,2'-dipyridyl. This potential operator sequence is distinct from the site recognized by the cyanobacterial Fur repressor homologue. No other nutrient stresses (nitrogen, sulfur, phosphorus) yielded the high level of induction seen following chelator treatment. These studies suggest that there may be more than one class of metal-dependent repressor in cyanobacteria.

Bacterial Proteins↗
PubMedDate not supplied

Normal ranges of ulnar and radial deviation with reference to ulnar variance.

We aimed to determine the normal ranges of radial and ulnar deviation of the wrist in relation to the ulnar variance. A total of 102 healthy subjects (204 wrists) were included in the study. The ranges of radial and ulnar deviation of the wrists were measured using a universal goniometer. Ulnar variance was assessed manually or radiographically, and recorded as ulna minus, ulna plus or ulna minus/plus. When the ranges of radial and ulnar deviation were compared with ulnar variance, ulnar deviation was greater in ulna minus subjects and radial deviation was greater in ulna minus/plus subjects. There was no significant difference in the total range of radio-ulnar deviation. The results of this study indicate that ulnar deviation is greater in ulna minus wrists, and we suggest that ulnar variance should be recorded alongside measurements of radial and ulnar deviation.

Adolescent↗
PubMedDate not supplied

Maroteaux-Lamy syndrome associated with growth hormone deficiency.

Growth retardation is a common feature of mucopolysaccharide storage disorders, mostly considered to be a consequence of skeletal changes, Maroteaux-Lamy disease is a subtype of mucopolysaccharidosis, demonstrating somatic changes and skeletal deformities. We present a case with Maroteaux-Lamy disease associated with growth hormone deficiency. Magnetic resonance imaging study revealed marked signal changes in white matter due to the storage in brain and empty sella appearance in sellar region. In the presence of empty sella syndrome, hypothalamic-pituitary dysfunction due to the storage material may have led to growth hormone deficiency in this patient. Therefore, we recommend patients with mucopolysaccharidosis, especially those who have growth retardation, to be evaluated by hormonal and radiological studies.

Child, Preschool↗
PubMedDate not supplied

Albumin excretion rate, serum insulin-like growth factor-I and glomerular filtration rate in type I diabetes mellitus at puberty.

The albumin excretion rate (AER), insulin-like growth factor-I (IGF-I) levels, glomerular filtration rate (GFR) and glycosylated hemoglobin (HbA1c) levels were studied in 49 diabetic children and 49 controls. The duration of diabetes varied from newly diagnosed to 17.5 years. Diabetics exhibited a wide range of AER values and had significantly higher AER and IGF-I levels compared to controls. At puberty elevated circulating growth hormone (GH) concentrations were found with a parallel increase in the levels of IGF-I. High IGF-I levels were found in 10-12 year-old girls and 15-16 year-old boys in both diabetic and control groups. Positive correlations were found between IGF-I and GFR in girls of both groups (p < 0.05) and in control girls between IGF-I, GFR and microalbuminuria (p < 0.05). The diabetic boys also showed microalbuminuria with respect to controls at high HbA1c levels and when their testis volume exceeded 8 ml (p < 0.05). We concluded that the prominent change in GH release at puberty, reflected by IGF-I, is in pulse amplitude, and that this is increased in diabetes but it is not a very important factor when determining the abnormal levels of urinary albumin excretion.

Adolescent↗
PubMedDate not supplied

MHC class I antigen expression in patients with IDDM and their siblings.

MHC class I antigen expression was found to be low on the lymphocytes of patients with insulin dependent diabetes mellitus (IDDM). Thus, it has been proposed that the defective expression of MHC antigens could lead to faulty immunological responses with the eventual destruction of the pancreatic beta cells. The objective in this study was to compare MHC antigen expression in IDDM patients and their presently healthy siblings. Nineteen children (mean age 10.8 +/- 3.9 years) with diabetes and their 25 siblings (mean age 10.7 +/- 4.6 years) were enrolled in the study. Peripheral blood lymphocytes isolated from venous blood samples were incubated with FITC conjugated monoclonal antibody W6/32. The amount of antibody binding by cell surface MHC class I antigens was assessed by flow cytometry. MHC class I molecule expression did not differ significantly among IDDM patients and their siblings. It was concluded that MHC class I antigen expression did not appear to be indicative of a susceptibility to develop autoimmune diabetes.

Adolescent↗
PubMedDate not supplied

The longitudinal effect of a single peritonitis episode on peritoneal membrane transport in CAPD patients.

OBJECTIVE: To evaluate the longitudinal effect of a single peritonitis episode on peritoneal membrane transport. DESIGN: A prospective longitudinal study. SETTING: Department of nephrology in a university hospital. PATIENTS: Eighteen continuous ambulatory peritoneal dialysis patients with peritonitis. METHODS: Peritoneal transport for low, middle, and high molecular weight (MW) solutes was evaluated by peritoneal equilibration test (PET). The first PET was performed on the day following the diagnosis of peritonitis. The test was repeated at weeks 1, 2, 4, 12, and 24 and the results were compared to baseline PET data obtained before peritonitis. In addition, dialysate CA125 concentration and leukocyte count were measured. RESULTS: During peritonitis there were significant increases in dialysate-to-plasma (D/P) ratios for all low, middle, and high MW solutes except potassium, and decreases in D4/D0 glucose ratio and ultrafiltration (UF) volume. Over the subsequent 2 weeks, solute transport gradually decreased to the baseline values then remained unchanged during follow-up. Although net UF volume demonstrated a similar course during the study, it did not completely return to the baseline value. No decrease in D/P sodium ratio was found at 60 minutes during the PET performed 24 weeks after peritonitis. The percent change in solute transport during peritonitis compared to baseline value was significantly correlated with a solute's MW (r = 0.776, p = 0.014). The slope of the regression line for D/P ratios versus MW, in double logarithmic scale, before peritonitis (-0.73 +/- 0.09) was steeper than the slope during peritonitis (-0.59 +/- 0.08). CONCLUSIONS: These findings indicate that a single peritonitis episode does not permanently affect peritoneal solute transport. However, the loss of net UF that accompanies peritonitis is not completely recovered, probably due to impairment of transcellular water transport. The transport changes associated with peritonitis may be due to the combined effect of increased effective peritoneal surface area and intrinsic permeability. Our findings suggest that the latter mechanism seems to be more important.

Adult↗
PubMedDate not supplied

Comparison of two hyaluronan drugs in patients with advanced osteoarthritis of the knee. A prospective, randomized, double-blind study with long term follow-up.

OBJECTIVES: To compare the long-term effects of high and low molecular weight hyaluronic acid (HA) applications in severe (Kellgren Lawrence stage III) osteoarthritis (OA) of the knee. METHODS: In a prospective clinical trial 184 knees (92 patients) with radiographic Kellgren Lawrence stage III OA were randomized to receive either 3 intra-articular high molecular weight HA (Hylan G-F 20) injections or 3 low molecular weight HA (Orthovisc) injections at one-week intervals. Patients were evaluated by the Hospital for Special Surgery (HSS) Knee Score and were followed-up for 12 months. RESULTS: The total HSS score in high molecular weight HA patients improved from 71.8+/-11.6 to 86.7+/-11.6 and in low molecular weight HA patients from 66.7+/-11.0 to 86.6+/-9.1 at the end of the trial (p < 0.01). There were no statistically significant differences between the groups and both had improved in all parameters at the latest follow-up (p = 0.000). CONCLUSIONS: Three intra-articular injections at intervals of 1 week of both HA preparations resulted in a pronounced reduction in pain and improved function as measured by the HSS score during a period of 52 weeks, without complications.

Double-Blind Method↗