Effects of piroxicam on natriuresis and kaliuresis in hypertensives and healthy volunteers

The effects of short-term piroxicam (P) treatment on natriuresis and kaliuresis were evaluated in 22 diuretic-treated hypertensives and 8 healthy subjects. Each hypertensive patient participated in three experimental periods, i.e., P 20 mg q.d. for 3 days and two control phases. Each healthy volunteer completed the six treatment phases, i.e., P 20 mg q.d. for 3 days, furosemide 40 mg orally in a single dose, P 20 q.d. for 3 days with furosemide 40 mg on the third day and three control phases. In healthy volunteers, P induced no change in 24-hour natriuresis and kaliuresis, but it reduced furosemide-stimulated natriuresis. In hypertensives with creatinine clearance (CCr) greater than 60 ml/min, P had no anti-natriuretic and anti-kaliuretic effects. In contrast, P induced a significant reduction in 24-hour natriuresis and kaliuresis in those with CCr less than 60 ml/min. Physicians should be aware of the potential risk of P-induced sodium retention and hyperkalemia, especially in patients with renal insufficiency, even though P was administered for only 3 days.

Lack of specificity of DA/DAPI fluorescence

Cytogenetic studies showed 47,XY, + mar in a developmentally retarded child with some features of Prader-Willi syndrome, and 46,XX in his mother. The marker chromosome showed a single subterminal primary constriction, bisatellites, and two C-bands. DA/DAPI staining showed two intense bands in the marker chromosome, which most likely was derived from chromosome 15. Intense DA/DAPI fluorescence was also found in one chromosome 13 in the child, and one 13 and one 10 in his mother. The present results confirm the reports of DA/DAPI heteromorphism in acrocentric chromosomes other than the 15, and demonstrate a pericentric DA/DAPI heteromorphism in chromosome 10.

Diagnostic value of ferritin measurements in patients with pleural effusions

The diagnostic value of ferritin measurements has been evaluated in 59 patients with pleural effusions (PE). The Mean(+/- standard error [SE]) PE-ferritin level was 1913 +/- 720 ng/ml in 10 patients with nonmalignant nontuberculous (nonTB) exudates (Group I), 594 +/- 110 ng/ml in 14 patients with TB effusions (Group II), 1286 +/- 194 ng/ml in 28 patients with malignant exudates (Group III), and 280 +/- 60 ng/ml in 7 patients with transudates (Group IV). Significant difference was found between Group II and Group III (p less than 0.05). The mean (+/- SE) ratio of PE/serum (PE/S) ferritin in Groups I, II, III, and IV was 3.5 +/- 1.1, 10.5 +/- 5.1, 4.9 +/- 1.0, and 2.0 +/- 0.7, respectively, and it showed no significant difference among Groups I, II, and III. There were good correlations between PE-ferritin and PE-LDH or S-ferritin, but no correlation between PE-ferritin and PE-protein. PE-ferritin revealed a considerable overlap among the exudative groups, and was of no value in the differentiation between malignant and nonmalignant (Group I + II) exudates. In the discrimination between exudates and transudates, the diagnostic accuracy (86%) of PE-ferritin was inferior to those (all 98%) of PE-protein, PE-LDH, PE/S protein ratio, and PE/S LDH ratio. Using PE-ferritin greater than or equal to 500 ng/ml in distinguishing malignant exudates from TB effusions, the sensitivity was 79%, specificity 57% and accuracy 71%.(ABSTRACT TRUNCATED AT 250 WORDS)

Single- and multiple-dose pharmacokinetics of ceftazidime in infected patients with varying degrees of renal function

To determine the single- and multiple-dose ceftazidime kinetics, we administered ceftazidime, 2 gm intravenous bolus every 12 hours, to 14 infected Chinese patients with various degrees of renal function. Blood samples were drawn in serial after the first and 7th dose and serum ceftazidime concentrations were measured by high pressure liquid chromatography. Ceftazidime concentration-time data were fitted to a two-compartment model with a nonlinear regression program. Ceftazidime kinetics was unaltered by repeated dosing. Both total body clearance and elimination rate constant of ceftazidime decrease significantly in proportion to the creatinine clearance estimated by Bjornsson's method. Renal insufficiency did not modify the steady-state volume of distribution (Vdss) of ceftazidime which, however, appeared to be larger than those reported previously. This larger Vdss may be explained by acute infection process, confinement to bed, and increased extracellular fluid volume as a result of hypoalbuminemia. Our study indicates the estimated creatinine clearance as a useful guide to ceftazidime dosage adjustment and also emphasizes the clinical relevance of conducting kinetic studies of antibiotics in infected patients.

Chromosome mosaicism in 6,000 amniocenteses

Multiple cell-multiple flask mosaicism was found in 0.20% of 6,000 amniocenteses, and multiple cell-single flask mosaicism was found in 0.92%. Multiple cell-multiple flask mosaicism usually was found in fetal or infant tissues at delivery or elective abortion. Most multiple cell-multiple flask mosaicism involved sex chromosomes and was either 45, X/46, XY or 45, X/46, XX. Except for one fetus with 45, X/46, XX and an aortic coarctation, phenotypic abnormalities associated with sex chromosome mosaicism were not found in these patients. One normal boy has continued to show 45,X mosaicism during the first 4 years of life. Autosome abnormalities found in multiple cell-multiple flask mosaicism included del(18q) associated with fetal anomalies. Apparently normal phenotypes were associated with prenatal trisomy 17, two de novo supernumerary marker chromosomes, and monosomy 21. Since an aberrant cell line present in only one primary amniotic fluid cell culture was occasionally identified from another amniocentesis or at birth, multiple cell-single flask mosaicism involving a sex chromosome or a viable autosome abnormality cannot be assumed to be an in vitro event. Maternal cell contamination, which was found in 0.49% of amniocenteses, could have resulted in an erroneous diagnosis of fetal sex in two cases if cells from independent culture vessels were not examined.

Sister chromatid exchanges in the human active and inactive X chromosomes

Four human female fibroblast strains with an i(Xq) or derivative X chromosome as a cytological marker for the inactive X chromosome were used to determine the frequency of sister chromatid exchanges (SCEs) in the active and inactive X chromosomes. No significant difference in SCE frequency between the active and inactive X chromosomes was observed. Therefore, the state of chromatin condensation and the late DNA replication in the facultative heterochromatin of the inactive X chromosome do not appear to influence the SCE frequency.

Lack of effects of calcium antagonists on red blood cell deformability in hypertension

To compare the red blood cell (RBC) deformability in hypertensive patients and healthy volunteers and to evaluate the effects of calcium antagonists on RBC deformability in hypertension, forty mild-to-moderate hypertensive patients and forty healthy volunteers, matched for age, sex and smoking habits, were studied. Each patient was randomized to receive one of the four following two-week treatment regimens: nifedipine 10 mg, verapamil 80 mg and diltiazem 60 mg three times a day and no drug. RBC deformability, measured with a gravity driven filtration technique, and mean arterial pressure were determined before and after the treatment. No difference in RBC deformability was observed between hypertensive patients and healthy volunteers. In contrast to the significant reduction in mean arterial pressure, RBC deformability was not altered by any of the three calcium antagonists. We conclude that a two-week treatment with calcium antagonist, at the effective vasodepressor dose, has no effect on RBC deformability in mild-to-moderate hypertensive patients.

Prenatal diagnosis of mosaicism for del(18)(q12.2q21.1) and a normal cell line

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DA/DAPI-fluorescent heteromorphism of human Y chromosome

Variation of DA/DAPI intensity in the Yq12 band was observed in five amniotic cell specimens and one blood specimen from the father of one fetus. Three distinct classes of Yq heterochromatin were identified by distamycin A (DA) treatment of the cell cultures and various staining techniques. The heterochromatin in the Yq11.23 sub-band does not undercondense when exposed to DA, and shows pale fluorescence with quinacrine staining, positive C-banding, and bright fluorescence with DA/DAPI technique. This class of heterochromatin was consistently observed in all specimens studied. The other two classes of heterochromatin are in the Yq12 band. Both show undercondensation when exposed to DA, quinacrine-bright fluorescence, and positive C-banding; however, one class of heterochromatin shows DA/DAPI-bright fluorescence and the other shows pale fluorescence. The size and banding intensity of the two classes of heterochromatin in Yq12 are variable. These results provide cytological evidence of heterogeneity within the Y heterochromatin region containing AT-rich DNA.

Establishment and characterization of a human urinary bladder carcinoma cell line (TSGH-8301)

A cell line derived from a well-differentiated human transitional cell carcinoma of the urinary bladder, designated TSGH-8301, was established in vitro. The cultured epithelioid cells exhibited monolayer growth and loss of contact inhibition. The tumorigenicity of TSGH-8301 had been shown by growth in soft agar and tumor induction in athymic nude mice. A reverse ratio of lactate dehydrogenase (LHD) isoenzyme in the cell line and nude mouse-grown tumors was seen predominantly with LDH-V. Chromosomal analysis revealed a heterodiploid stem line with a modal number of 50. Sera of urinary bladder cancer patients reacted with membrane antigens of the TSGH-8301 cells, suggesting the existence of tumor-associated antigens in the cells. In vitro chemosensitivity tests of these cells may provide data valuable in the selection of proper anticancer drugs for the TSGH-8301 donor patient.

Prazosin-induced first-dose phenomenon possibly associated with hemorrhagic stroke: a report of three cases

A small initial dose of prazosin ranging from 0.5 to 1 mg has been recommended to avoid the first-dose phenomenon characterized by a sudden and severe drop in blood pressure after the administration of the first dose of prazosin. However, even with an initial dose of 0.5 mg, hypotension with consciousness disturbance developed in three hypertensive patients with recent cerebral hemorrhage. We present this report to alert physicians and pharmacists about the potential risk of the first-dose phenomenon even at the recommended initial doses of prazosin in hypertensive patients who have suffered a recent stroke.

Expression of fragile X in human-mouse somatic cell hybrids

Fragile X expression was studied in human-mouse cell hybrids prepared from lymphocytes and fibroblasts obtained from a mentally retarded male. The patient showed a fragile X in 29-35.5% of his lymphocytes in medium 199 (M199) and in M199 plus fluorodeoxyuridine (FdU). One lymphocyte hybrid clone showed no expression in M199 and low expression in M199 + FdU. The other lymphocyte hybrid clone showed significantly increased expression in both media, comparable to levels in the parental cells. Fibroblast cultures from the patient showed no fragile X expression in M199 and 17% expression in M199 + FdU. Fragile X expression was also found in fibroblast hybrid clones in M199 and was significantly enhanced by the addition of FdU. Fragile X expression in one clone was consistently lower than in the other two clones and in the parental fibroblasts. Our results indicate that the level of fragile X expression varies in the hybrid clones, since frequencies similar to those of parental cells and suppressed frequencies were found. The presence or absence of a specific human chromosome did not correlate with the level of fragile X expression.

Effect of C-banded heterochromatin on centromere separation

The present study is to determine the effects of centromeric heterochromatin on centromere separation. Amniotic cell cultures in which the centromeric heterochromatin of one chromosome was at least twice as large (qh+) as the heterochromatin (qh) in the homologous chromosome were selected. Fifteen amniotic cell samples with 1qh+, 9qh+ or 16qh+ were studied. The size of the centromeric heterochromatin was directly correlated with the delay in centromere separation. The chromosome with the smaller centromeric heterochromatin tended to show earlier centromere separation than the homologue with the larger heterochromatin. Our results suggest that the quantity of centromeric heterochromatin may influence the genetic control of centromere separation.

Two-point T1 measurement: wide-coverage optimizations by stochastic simulations

Stochastic reliability of T1 measurement from image signal ratios is examined in the ideal case by stochastic simulations in the context of wide-coverage optimizations. Precise measurements prove to be accurate, and accurate ones precise. Sign-preserved inversion-recovery (IR)/non-IR techniques are the best ratio method, reciprocal non-IR/IR ones being equivalent, but inconvenient. Wide-coverage optima are relatively unsharp. Suggested guidelines for covering the 150- to 1500-ms T1 band are minimal relevant TE; TI about 400 ms; effective repetition times about in the ratio, TR2(IR)/TR1 (non-IR) = 2.5-3.0, and in a sum as long as possible up to about TR1 + TR2 = 3.5-4.0 s; signal-averaging after and only after TR1 + TR2 has been lengthened to the said region. Also suggested are different guidelines for covering T1 bands, 120-1200 and 200-1800 ms. Typically, precisions and accuracies improve linearly or faster with increasing S/N and (S/N)2, respectively. Unnecessarily high pixel resolutions or thin slicings exact great penalties in accuracies. Progressively shortening TR1 eventually transforms a wide coverage into a sharp targeting with small potential gains in a narrow T1 locality and large compromises almost everywhere else. The simulations yield an insight into applicabilities of standard error propagation analyses in two-point T1 measurement.

Numerical T1 computation from NMR intensity ratios

Two-point measurement of tissue T1 from NMR intensity ratios consists of forming an a priori ratio function describing a T1 dependence of the ratio R(T1) and computing T1 from an observed ratio Q by numerically solving R(T1)-Q = 0 or an equivalent equation. Impact of R(T1) designs on the numerical computation and dependence of relative speeds of three numerical methods on desired computational precisions q and on other factors are examined. All three methods begin with computing a table of R(T1) entries in uniform T1 steps (delta T1). In two iterative methods, a step containing the T1 root is looked up, and the precise T1 location within the step is pinpointed to within a q value by either linear-interpolative (LI) or Newton-Raphson (NR) iteration. The third method simply consists of computing a large table of delta T1 = q for a mere "look-up" with no iterative search. All three methods require a monotonous R(T1) for uniformly effective computation over wide T1 ranges. Speeds of either iterative method for computing T1 images are expected to vary with delta T1 and q with unsharp speed maxima at delta T1 near 20, 6, and 2 ms for q = 10(-1), 10(-2), and 10(-3) ms, respectively. Either iterative method is suitable for both low- and high-precision computations, the LI method being generally faster. The simple look-up is the fastest of the three for T1 image computation to low precisions of q greater than or equal to 1 ms, is likely the slowest for that to q = 0.1 ms, and is impractical for that to q less than or equal to 0.01 ms.