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Biomedical subjects

A Ty

Publications and source records attributed to A Ty.

18 recordsLinked to original sources
PubMed2004

Pineal yolk sac tumour with a solid pattern: a case report in a Chinese adult man with Down's syndrome.

Intracranial germ cell tumours are rare. The incidence of primary intracranial yolk sac tumour is even more uncommon, with only two reported cases being associated with Down's syndrome in the English literature. This report details the findings of yolk sac tumour in the pineal region affecting a 22 year old Chinese man with Down's syndrome. Histology revealed yolk sac tumour with only a solid pattern, potentially mimicking the more common germinoma in the pineal region. No other germ cell components were identified. This is the third report of intracranial yolk sac tumour manifesting in a patient with trisomy 21. The pathology of this tumour and its differential diagnoses are discussed.

Adult↗
PubMed1998

Childhood lead screening knowledge and practice. Results of a New Jersey physician survey.

CONTEXT: As the nation moves toward targeted childhood lead screening, CDC continues to recommend universal screening in states with no childhood lead poisoning prevalence data. OBJECTIVE: The study was conducted, prior to the new universal screening state law, to determine physician screening practices and their consistency with key CDC recommendations as a basis for future education activities. DESIGN/SETTING/PARTICIPANTS: A statewide cross-sectional self-administered multiple choice survey of 541 randomly selected New Jersey pediatricians and family practitioners. OUTCOME MEASURES: Risk assessment, screening and case management practices and their consistency with CDC recommendations. RESULTS: We obtained 333 usable responses (69.4%). Most respondents reported confirming blood lead level, initiating case management, and identifying medical emergencies at blood lead levels lower than recommended by CDC. More than half reported not assessing the risk of the majority of their patients. At least one third were not screening infants, children between 1 and 2 years, or children between 2 and 6 years of age. Physicians who assessed risk tended to screen high-risk children in all age groups. Only 42% of pediatricians and 24% of family practitioners said they screened the majority of the children in their practice by age 2 years. About 60% of all respondents reported not providing lead exposure education to half their patients. CONCLUSIONS: Passing a universal screening law, as New Jersey has done, is one way to obtain baseline childhood lead poisoning prevalence data. Private practice-targeted physician education led by preventive medicine specialists may also be helpful.

Child↗
PubMed1988

Blood pressure elevation in young dogs during low-level lead poisoning.

Clinical and experimental studies suggest an association between low-level lead exposure and hypertension. This association was investigated in six 3-month-old dogs who were randomly paired with their littermates. The daily oral dose of lead acetate was 1.0 mg Pb/kg body wt for 5 months; the controls received equimolar sodium acetate. Blood pressure was measured indirectly without anesthesia and was similar in the two groups at the start of the study. The mean blood pressure was higher in the lead-exposed group at every follow-up, from 10 days to 20 weeks. This treatment group difference in profiles was statistically significant (repeated-measures ANOVA, p = 0.0048). The final mean blood pressures were 120 +/- 6.4 (x +/- SE) vs 108 +/- 1.5 mm Hg. At 4 weeks the plasma renin activity was higher in the lead-exposed group: 3.4 +/- 0.25 vs 1.2 +/- 0.15 ng/ml/hr. The difference decreased during the study but the elevated trend persisted (repeated-measures ANOVA, p = 0.014). Lead exposure did not alter renal functions or extracellular fluid volume. This study shows that low-level lead intake in young dogs can cause an early increase in blood pressure which persists during ongoing exposure and which is associated with a small increase in the activity of the renin-angiotensin system.

Analysis of Variance↗
PubMed1987

Sodium deprivation growth failure in the rat: alterations in tissue composition and fluid spaces.

Dietary control of sodium intake was utilized in weanling rats to study the relationships among body growth, tissue composition and extracellular fluid volume (ECFV). Forty 3-wk-old rats were divided into groups receiving 30, 150, 300, 600 or 900 mu eq sodium/d for 5 wk. The minimal daily requirement for normal growth was 300 mu eq Na, or about 60 mu eq/g of new growth. Lower doses caused dose-related growth failure associated with a reduced ECFV. Analyses of carcass, muscle and bone composition were carried out. In sodium-deprived animals there was retarded growth of protoplasm, fat and bone; the mineral composition of muscle was not altered, whereas in bone calcium concentration was reduced. Plasma concentrations of sodium, potassium and chloride remained normal. Pair-feeding indicated that sodium-deficiency growth retardation could not be attributed to starvation. Sodium-deficient animals ingested a greater amount of food per gram of weight gain, possibly reflecting an increased energy expenditure. Sodium deprivation initially permitted protoplasmic growth to proceed at a rate disproportionate to that of the ECFV. Subsequently, both continued to grow at a reduced but similar rate, suggesting that ECFV may be a controller of protoplasmic growth.

Animals↗
PubMed1987

Diuretic-induced growth failure in rats and its reversal by sodium repletion.

The aim of diuretic therapy is the prevention of excessive sodium accumulation. However, sodium retention is necessary for growth. Inasmuch as many of the clinical conditions for which diuretics are used are associated with growth retardation, we investigated the influence of diuretic therapy on growth in an animal model. In Part I, 32 weanling Sprague-Dawley rats were fed a diet adequate for growth which contained 0.08% sodium and 0.17% potassium. Daily i.p. injections of saline (0.4 ml) containing furosemide in doses of 0, 50, 100 or 200 mg/M2 were given for 9 days. There was a dose-related reduction in weight gain which could not be explained by lower food intake. The highest dose group gained only 58% as much as the control group. Balance studies and muscle, bone and carcass analysis demonstrated that this was accounted for by decreases in protoplasmic, bone, fat and extracellular fluid volume accretion. In Part II, 32 weanling rats, all treated daily with furosemide (100 mg/M2 i.p.) received replacement of NaCl, KCl, both or neither in their drinking water. Sodium replacement resulted in increased growth rates whereas potassium replacement alone had no effect on growth. Sodium replacement also increased the balance of all measured minerals. We conclude that diuretic therapy causes growth retardation by preventing retention of sodium needed for growth.

Animals↗
PubMed1979

Membranous nephritis in infantile systemic lupus erythematosus associated with chromosomal abnormalities.

A white female infant who developed a sudden onset of gross hematuria and proteinuria at 3 months of age was referred for evaluation of nephrotic syndrome at 6 months. Laboratory investigations revealed severe Coomb's negative hemolytic anemia, leukopenia, thrombocytopenia, hypocomplementemia and elevated anti-nuclear antibody titer and DNA antibodies. Renal biopsy showed a membranous type of morphology. She was also found to have chromosome abnormalities. She had an eventual favorable response to steroid therapy. Systemic lupus erythematosus (SLE) is rarely seen in young infants and the renal expression of the disease found in our case has never been reported.

Chromosome Aberrations↗
PubMed1973

Demonstration of antigenic sites in glomeruli of patients with acute poststreptococcal glomerulonephritis by immunofluorescein and immunoferritin technics.

The presence and localization of antigenic sites in glomeruli of 14 patients with acute poststreptococcal glomerulonephritis (AGN) were studied by immunofluorescein and immunoferritin technics. Labeled IgG fractions from the same patients were used for the identification of antigenic sites. The staining capacity of these IgG fractions depended on the time when sera were obtained. Staining was minimal during the first week, and increased up to the fourth or fifth week. Glomeruli, however, stained only when renal tissue was obtained during the early phase of the disease. Precise localization of antigenic sites was determined with ferritin-conjugated patients' IgG. Segmental deposition of ferritin was observed in the mesangial matrix and on the endothelial side of the glomerular basement membrane. Subepithelial electron-dense deposits contained no or very few ferritin particles. In contrast, ferritin-conjugated antihuman IgG was distributed diffusely in the mesangial matrix, on the endothelial side of the basement membrane and in subepithelial deposits. These findings suggest that, during the early stage of acute poststreptococcal glomerulonephritis, free antigen is present in the glomeruli of patients with this disease.

Acute Disease↗
PubMed1970

Partial characterization of antigenic streptococcal plasma membrane components in acute glomerulonephritis.

Fluorescein-labeled immunoglobulin G (IgG) fractions of serum from patients with acute poststreptococcal glomerulonephritis stained parts of the glomerular basement membrane and mesangium of kidney tissue obtained from the same patients during the early phase of the disease. Renal tissue obtained from normal individuals and from patients with other kidney diseases failed to stain with these IgG fractions. Preabsorption of the serum fractions with various freezethawed bacteria demonstrated that only certain group A streptococci abolished the staining capacity. Fractionation of the streptococci into cellular constituents indicated that it was predominantly the plasma membrane fraction which blocked the immune staining. Spectrofluorometry using alkali-solubilized renal tissue confirmed these observations in a quantitative manner. By sucrose density-gradient ultracentrifugation of the plasma membrane two possible antigens were isolated. One was soluble in phosphate-buffered saline and the other was insoluble. The soluble component was a lipoprotein with a molecular weight of approximately 120,000.

Adult↗
PubMed1969

Antigenic streptococcal components in acute glomerulonephritis.

Fluorescein-labeled immunoglobulin G fractions from serums of patients with acute glomerulonephritis and from many normal serums stained the glomerular basement membrane and mesangium of renal tissue from patients with early acute glomerulonephritis; these serums did not stain the corresponding tissues from patients with any other kidney disease. Previous absorption of the serum fraction with frozen and thawed nephritogenic beta hemolytic streptococci abolished all staining. Other bacteria studied did not abolish the staining. Only the plasma membrane of the streptococcus absorbed the immunoglobulin G fraction; such absorption eliminated staining. Fluorescein-labeled antiserums against streptococcal plasma membrane had staining properties similar to patients' serums.

Absorption↗
PubMedDate not supplied

Clinical application of in vivo tibial K-XRF for monitoring lead stores.

We used in vivo tibial K-x-ray fluorescence for clinical evaluation of bone lead stores in 31 patients suspected of excessive lead absorption. Four clinical situations were examined: (1) postchelation therapy, (2) renal failure, (3) home exposure, and (4) occupational exposure. K-x-ray fluorescence assisted in determining the magnitude of body lead stores in patients with known excessive lead exposure. Serial measurements revealed a reduction in bone lead that occurred over the years, during which there was an absence of continued exposure; this reduction occurred more rapidly during chelation therapy. Sustained high bone lead levels following chelation therapy in two children were consistent with elevated lead stores from prior pica. In a patient with renal failure, K-x-ray fluorescence demonstrated massive lead stores at a time when chelation testing was not possible. In other cases, bone lead levels indicated the possible contribution of lead nephropathy to renal diseases of other etiologies. In individuals exposed to lead during home renovations, K-x-ray fluorescence provided reassurance that past exposure did not result in elevated body lead stores decades later. In the occupational setting, K-x-ray fluorescence documented cumulative lead stores in workers whose exposures varied in intensity and duration. The examples discussed here show how physicians can use K-x-ray fluorescence to deal with practical questions of patient management. As the test becomes more generally available, its safety, specificity, and simplicity should make it an important alternative to cumbersome chelation tests and potentially misleading blood lead measurements.

Adult↗