Combination of low-dose epidural morphine and intramuscular diclofenac sodium in postcesarean analgesia

Epidural morphine is used for postcesarean analgesia, and nonsteroidal antiinflammatory drugs are frequently administered to relieve uterine cramps after vaginal delivery. To assess the efficacy of a combination of low-dose epidural morphine and intramuscular diclofenac sodium in postcesarean analgesia, a double-blind, randomized study was conducted. Epidural anesthesia was given to 120 parturients who were randomly allocated into four treatment groups: group A received normal saline solution, 10 mL epidurally and 3 mL intramuscularly (IM); group B received 10 mL of epidural saline solution and 75 mg (3 mL) of diclofenac IM; group C received 2 mg of morphine in 10 mL of epidural saline solution and 3 mL of saline solution IM; and group D received 2 mg of morphine in 10 mL of epidural saline solution and 75 mg of diclofenac IM. Epidural injections were given after delivery of the placenta, and IM injections were given on arrival in the recovery room. Verbal analogue pain scores were recorded at 2, 4, 8, 12, 18, and 24 h after epidural injection. Subjective scores of overall pain relief were also recorded at 24 h. Results showed that scores of overall pain relief were significantly better in group D compared with group A, B, or C (P less than 0.05). Groups A and B required more supplemental meperidine than groups C and D. None of the subjects in group D requested supplemental analgesia. Compared with the other three groups, group D experienced a better analgesic effect for both wound pain and uterine cramping pain from 4 to 18 h (P less than 0.05). Incidence of nausea or vomiting, or both, and pruritus occurred more frequently in groups C and D compared with group A or B (P less than 0.05). No bradypnea was observed during the study period. Diclofenac alone was not effective in postcesarean analgesia.(ABSTRACT TRUNCATED AT 250 WORDS)

I-131 NP-59 adrenal cortical scintigraphy in suspected primary aldosteronism

Dexamethasone suppression [Iodine-131] 6-Beta-Iodomethy1-19- Norcholesterol (I-131 NP-59) adrenal cortical scintigraphy was performed in 35 patients with suspected primary aldosteronsim, between May 1983 and June 1990. Based on clinical, biochemical, radiographic and pathologic data, the diagnostic accuracy of primary aldosteronism from I-131 NP-59 adrenal cortical scintigraphy was evaluated. The sensitivity, specificity, positive predictive accuracy and negative predictive accuracy was 78.9%, 100%, 100% and 80% respectively. We conclude that I-131 NP-59 adrenal cortical scintigraphy is an accurate and noninvasive technique for the diagnosis of suspected primary aldosteronism.

Application of staining of nucleolar organizer regions in cytological smears of the bronchus

An argyrophil technique for the staining nucleolar organizer regions (AgNOR) was applied to cytological preparations obtained from bronchoscopic brushing materials. The number of AgNOR has been thought to be related to cellular activation. To differentiate malignant cells from non-malignant atypical cells, this study was carried out in 20 cases of adenocarcinoma of the lung (mean AgNOR: 18.34), 12 cases of pulmonary inflammatory diseases (mean AgNOR: 6.54) and 10 normal bronchial epithelial specimens for control (mean AgNOR: 2.07). On the basis of AgNOR number, we could differentiate between the three groups. The differences observed were statistically highly significant (p less than 0.0001). Moreover, the nucleolar organizer regions (NOR) in cancer cells were found the more irregularly distributed and more variable in sized than those in atypical and normal bronchial columnar cells. We suggest that the AgNOR technique will find increasing application as a complementary test in diagnostic cytopathology.

The predictability of matched ventilation perfusion scan in pulmonary embolism

In retrospect, we reviewed 17 cases of proven pulmonary emboli at Taichung VGH. These patients were then divided into two groups, the matched and the mismatched V/Q scan. Patients with lung consolidation, along with their chest films, were studied and characterized. In the matched V/Q group (5 cases), perfusion defects were comparable with lung consolidation in both size and location. In the V/Q mismatched group, perfusion defects were larger than lung consolidation (either single or multiple foci). A matched V/Q scan in patients with a pulmonary embolism, may result from lung consolidation induced by a pulmonary infarction, localized edema, or hemorrhage. A matched V/Q scan with localized lung consolidation in a suspicious case could not rule out pulmonary embolism, and further evaluation is mandatory.

Monozygotic twins of discordant sex both with 45,X/46,X,idic(Y) mosaicism

A female twin with short stature, unusual facial appearance, widely spaced nipples, and coarctation of the aorta was found to have a peripheral blood lymphocyte karyotype of 45,X(43%)/46,X,idic(Y)(p11). Her twin brother, also short with similar facial appearance, had the same mosaicism (40% 45,X). Cultured skin fibroblast studies showed discrepant karyotypes of 45,X (100%) in the girl and 45,X (78%)/46,X,idic(Y)(p11) in the boy. The mother and the father had normal chromosomes. Comparison of 27 biochemical markers yielded a likelihood of monozygosity of 0.9977. This report documents the occurrence of discordant phenotypic sex in monozygotic twins, involving gonadal dysgenesis with an abnormal dicentric Y, which presumably occurred de novo, followed by anaphase lag probably before the occurrence of twinning. Unequal distribution of the two resultant cell lines in various tissues of each twin could account for the development of the very different phenotypes, apparently normal boy and Ullrich-Turner girl.

Field uniformity of the Japonica rice region of Taiwan as estimated by relative genetic contribution

Despite the concerns for genetic vulnerability that were raised in the 1970s, the field uniformity of the Japonica rice (Oryza sativa L.) region in Taiwan has increased since 1980 with over 82% of the cultivated areas being covered by as few as three varieties and over half of this hectarage by a single variety. Japanese plant introductions are the major ancestral contributors of genetic constituents for varieties released in Taiwan. The main constitution of the genetic base present in the field has changed little since 1971. Six common ancestors comprised 60%, 55%, 78%, and 77% of the genetic constituents present in the field in 1971, 1976, 1981, and 1986, respectively. These estimates revealed that at least 55% of the genes utilized in the last 15 years came from the same sources. Recent efforts in introducing new germ plasm sources to variety development should continue to alleviate the possible crop loss due to continuous monoculture.

Lack of effect of labetalol on platelet aggregation in hypertensive patients

To evaluate the ex-vivo effects of labetalol, at effective vasodepressor doses, on platelet aggregation in hypertension, 30 hypertensive patients were randomized to either a labetalol or control group in a ratio of two to one. For the labetalol group, the dosage was titrated from 400 mg to 600 mg per day to achieve a fall of 10 mmHg in mean arterial pressure (MAP). No drug was used in the control group. The study lasted for 4 to 8 weeks. At the beginning and end of the study, platelet aggregation to collagen, adenosine diphosphate and epinephrine were measured according to Born's method. In contrast to the significant reduction in MAP, platelet aggregation was not altered by labetalol compared with the control group. Our data do not support the hypothesis that labetalol, at effective vasodepressor doses, inhibits platelet aggregation in mild-to-moderate hypertensive patients.

[Acetabular roof reconstruction with femoral head bone-graft for severe acetabular deficiency in total hip replacement]

From July 1984 to September 1989 at Taichung Veterans General Hospital, 14 patients (15 hips) received femoral head bone-grafting by modified Harris method as a part of their total hip replacement for acetabular bony deficiencies. They were followed up for an average of 31.7 months (range from 7 to 66 months). The clinical results were classified as excellent (58.3%) and good (41.7%) by Harris hip scoring system. All the grafts presented as "solid incorporation" with the pelvic wall and only one of the grafts was assessed to be "definite resorption" (volume reduction greater than 50%) by radiologic study. The "biologic viability" of these grafts were proved to be positive by scintigraphy in three-dimensional technique (SPECT). According to our limited experience and primary follow-up studies, we found that good clinical results depend on ideal positioning of the acetabular component in the true acetabulum and femoral head bone-grafting is an ideal procedure for the reconstruction of severe acetabular dysplasia in total hip arthroplasty.

Reflex sympathetic dystrophy and electroacupuncture

Reflex sympathetic dystrophy (RSD) is a painful and progressively debilitating condition. Untreated, it leads to changes in the patient's lifestyle that are consistent with chronic pain syndrome. This general overview of contributing factors, signs and symptoms, diagnosis, and treatment of RSD presents three consecutive cases for which electroacupuncture (EA) proved to be an effective treatment for RSD pain. Possible underlying neuroanatomical mechanisms of RSD are addressed and the scientific basis for EA is considered briefly.

[Comparison of nasal mucociliary clearance before and after operation in chronic sinusitis]

Nasal mucociliary clearance is a first line of defence mechanism of the respiratory system against inhaled particles. It transports particles depositing into the nasal passages to the pharynx to be swallowed or expectorated, thus protecting the respiratory system from injury. Clearance function is affected by many factors such as the chronic inflammation of the paranasal sinuses. A group of 13 healthy volunteers (controls) and a group of 17 patients suffering from chronic sinusitis was investigated in the Department of Otolaryngology of Taichung Veterans General Hospital between June and October of 1990. A radioisotope method was used to measure the velocity of nasal mucociliary transport in the participants. This involved the use of radioisotope Tc99m combined with albumin particles and measurements were made in one nasal chamber at a time. The sinusitis patients were then surgically treated and they all improved. In all 25 tests were made in the control group and the mean velocity of their mucociliary transport was found to be 4.56mm/min. In the patients 28 measurements were made and their mean velocity was found to be 2. 67mm/min before the operation and 4.03mm/min after the operation. The difference between pre- and post-operative velocities was statistically significant as was the difference between the pre-operative velocities of the patients and those of the controls. The difference between controls and patients after the operation was not significant.

Quantitative 99Tcm-HMPAO white blood cells and 67Ga scanning in rheumatoid arthritis

This investigation assessed 99Tcm-HMPAO white blood cell (Tc-WBC) and 67Ga knee uptake indices before and after 90Y treatment in patients with intractable rheumatoid arthritis (RA) and correlated the uptake indices with the clinical score. Sixteen knee joints with RA were treated with intra-articular injection of 185 MBq of 90Y-silicate colloid (Amersham) flushed with 50 mg of hydrocortisone. Clinical score, quantitative 67Ga and Tc-WBC knee uptake indices were obtained before and three weeks after treatment. Our results showed that 9/16 (56%) had a good response and 7/16 (44%) had a poor response to 90Y injection. There was poor correlation between clinical improvement and changes in 67Ga and Tc-WBC knee uptake indices (r = 0.46 and 0.14, respectively). The correlation coefficient between changes in 67Ga and Tc-WBC knee uptake indices was 0.29.

Anaerobic growth and oxygen toxicity of Rhizopus cultures isolated from starters made by solid state fermentation

To explore the relationship between Rhizopus growth and its microaerophilic characteristics the present study was undertaken. A survey of 18 Rhizopus cultures growing in anaerobic or microaerobic condition found that 11 of the cultures grew quite well under microaerobic condition, but all the cultures grew poorly under absolutely anaerobic condition. Among the 18, 8 showed definitely banded mycelial growth below the surface of the medium in the tube. Six of 18 cultures--RT-1-8, RT-43, RT-46, A-1, C-1, and E-1--grew with much aerial hyphae when they were cultivated on media supplemented with different detoxifying agents under aerobic condition. These six strains are comparatively sensitive to oxygen toxicity (H2O2 or O2- or OH.) under aerobic condition, as many microaerophilic bacteria are. There were nine strains whose aerial hyphal growth was greatly enhanced by the presence of Aspergillus niger catalase. However, the growth of the majority of the cultures was not influenced by supplements of bovine liver catalase or bovine liver superoxide dismutase. In conclusion, some Rhizopus cultures from the starters exhibited both microaerophilic and aerobic growth. The phenomena of growth in low O2 condition, and the subsurface growth of mycelia in tubes, may provide a clue to exploitation of the microaerophile-like characteristics in some starter molds.

Comparison of pulmonary tuberculosis in younger and elderly patients

Pulmonary tuberculosis remains a significant clinical and public health problem in the elderly population. To describe age-related differences in disease manifestations, a comparison of the clinical features, predisposing factors, diagnostic approaches and radiographic findings in cases of pulmonary tuberculosis among 52 young and 62 elderly patients was performed. The elderly patients had a higher number of underlying disease than younger patients (p less than 0.05). Prior to admission, symptoms occurring with equal frequency in both younger and elderly patients included coughing, malaise, and weight loss. Elderly patients had significantly higher incidences of negative reactions to the PPD test (p less than 0.05). Radiographic findings revealed that upper lung field infiltrates were still common in both groups, but the elderly had more severe lung field involvement (two or more lobes affected), and more frequent pleural reactions than younger patients (p less than 0.05). Since there were non-specific clinical features, false negative skin test and complex radiographic manifestations, tuberculosis was frequently not suspected in the differential diagnosis, especially among elderly patients with multiple medical problems. We suggest that physicians need to have a high level of suspicion and awareness of varied manifestations for tuberculosis, especially elderly patients.

Quantitative C-reactive protein in pulmonary infections

A total of 207 cases were selected to evaluate the diagnostic value of C-reactive protein (CRP) in pulmonary infections. The mean +/- SD of CRP values in various pulmonary infections were as follows: 18.62 +/- 11.34 micrograms/ml for 32 cases of exudative-fibrotic tuberculosis; 15.98 +/- 16.66 micrograms/ml for 15 cases of tuberculous pneumonia; 25.61 +/- 18.96 micrograms/ml for 29 cases of tuberculous effusion; 16.66 +/- 10.18 micrograms/ml for 11 cases of tuberculous cavity; 81.1 +/- 24.9 micrograms/ml for 10 cases of miliary tuberculosis; 36.4 +/- 22.1 micrograms/ml for 19 cases of mycoplasmal pneumonia; 241 +/- 72 micrograms/ml for 38 cases of bacterial pneumonia; 225 +/- 65 micrograms/ml for 30 cases of bacterial pneumonia with effusion; 169 +/- 50 micrograms/ml for 16 cases of lung abscess. The CRP values of other pulmonary infections were as follows: 20.6, 20.8 micrograms/ml for two cases of Strongyloides stercoralis pneumonia; 7.4, 1.6 micrograms/ml for two cases of aspergilloma; 11.2, 12.4, 7.6 micrograms/ml for three cases of Pneumocystis carinii pneumonia. Serial changes in CRP values in 13 cases of well-treated bacterial pneumonia showed that values of CRP decreased to below half of the initial value on the 3rd to 4th day, and returned to about normal value on the 10th to 13th day. The study suggested that: a) various types of infections had different levels of CRP values, b) level of CRP values was determined both by the pathogen and the severity of inflammation, c) serial CRP values in bacterial infection could be used as a guide in treatment.

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

Images

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.

The prenatal detection of the fragile X chromosome: review of recent experience

The fragile X chromosome has been identified in specimens from 17 male and 10 female fetuses in 11 laboratories throughout the world, obtained from at least 79 fetuses at increased risk for the fra(X) syndrome. Of these, 19 were confirmed, 6 were pending, 1 was negative and 1 could not be confirmed. Twenty-five of the 79 cases were studied in our laboratory (Institute for Basic Research [IBR]) and resulted in fra(X) demonstration in specimens from 3 male and 5 female fetuses. All 3 males and 2 of the 5 females have been confirmed. When amniocytes from the two confirmed female fetuses were exposed to FUdR after culturing in Chang medium, fra(X) frequencies were virtually negative indicating that Chang medium should not be used in fragile X studies at least when FUdR is used to induce fragility. Finally, amniocytes from a fra(X) male fetus studied in 3 different laboratories exhibited strikingly different frequencies. To date, we have experienced no false-positives or negatives, but the latter case was controversial. It is recommended that laboratories undertaking fra(X) prenatal detection use a combination of at least two different proven induction systems as well as complementary DNA marker studies to prevent false negative diagnosis.

Trisomy 14 mosaicism with t(14;15)(q11;p11) in offspring of a balanced translocation carrier mother

A 2-year-old girl with growth and developmental retardation, minor facial anomalies, asymmetry of face and body, tetralogy of Fallot, and reticular hyperpigmentation of the skin was found to have mosaic trisomy 14 involving a t(14;15)(q11;p11). The patient showed mosaicism for 46,XX cell line, apparently resulting from a break of the translocation chromosome and a subsequent loss of 14q. The mother has a balanced translocation t(14;15)(q11;p11). Inherited trisomy 14 has not been reported previously.

Reduction of fragile X expression in blood after cryopreservation

Frequency of fragile X expression was investigated before and after cryopreservation (-196 degrees C) in the blood of 4 affected males, 3 fragile X carriers and in a fibroblast cell strain from a fragile X male fetus. The results indicate that there is a significant decrease (p less than 0.05) in the frequency of the fragile X expression in lymphocytes after cryopreservation, as compared to the fresh blood, but not in fibroblasts. This suggests that cryopreserved blood specimens may not be suitable for fragile X analysis.

Interpolative computation of spin-lattice relaxation times from signal ratios

An iterative linear interpolation is described for computing T1 estimates from image-signal ratios that are monotonous functions of T1. Whether the function decreases or increases with T1, the same algorithm described applies. The iterative process converges readily. Narrowing the whereabouts of T1 sought in lookup tables to T1 regions just small enough to require only a few subsequent interpolations tends to shorten overall T1 image computing time. Used with imaging methods for which the function is readily evaluated, the iterative interpolation allows a rapid and precise T1 computation compatible with variable choice of pulse-sequence parameters. The flexibility is suitable to stochastic analysis of T1 measurement from signal ratios. Examples of applications to computing the stochastic uncertainty represented either by crude indicators or by standard statistical quantities are given. A method of stochastic simulation yielding the statistical quantities is described.

Accuracy of proton T1 calculated by approximations from image signals

In proton magnetic resonance imaging, T1 calculation from two measurements is simplified by using an approximation algorithm that assumes equilibrium recovery of longitudinal magnetizations or one that ignores refocusing 180 degrees pulses used. Errors in calculated T1 arising from either approximation are evaluated using signal expressions that presume neither approximation. The approximation error depends on T1, sequence parameters, and the simplifying algorithm. The computed relation can be used to correct for the approximation error. The correction reduces calculated-T1 errors, but does not eliminate them, since other significant or potentially significant sources of the error are unaccounted for. These sources relate to ever-present stochastic noises, proper signal expressions, various instrumental factors, exponential compared with nonexponential nature of tissue proton relaxations, and tissue movements. The problem of quantitative T1 measurement from image signals is briefly discussed.

Effect of oral dose size on hydralazine kinetics and vasodepressor response

Levels of hydralazine in blood are log-linearly related to its vasodepressor effect. We examined the effect of oral dose size on the proportion of hydralazine that reaches systemic circulation. Nine subjects with hypertension were given hydralazine in oral doses in the therapeutic range. Blood hydralazine levels, effective liver blood flow, blood pressure, and heart rate were measured. As the hydralazine dose increased, the ratios of the AUC of hydralazine to hydralazine dose and of peak blood hydralazine concentration to hydralazine dose increased, indicating an increase in the proportion of the dose in blood. Liver blood flow tended to increase (maximum 40%) as dose increased above 0.5 mg/kg. Vasodepressor response and degree of tachycardia increased disproportionately with increasing hydralazine dose. There were strong log-linear relationships between peak hydralazine levels and both vasodepressor response and tachycardia that did not change with increasing hydralazine dose. Thus blood hydralazine and vasodepressor response increase disproportionately with increasing hydralazine doses in hypertension.