White clot syndrome

Heparin therapy is currently a vital component in the medical management of thromboembolic events. Despite its widespread use, it is associated with relatively few complications, and these are usually minor and quickly reversible. Recently a much more dramatic and serious complication of heparin therapy has been identified. In heparin-induced thrombocytopenia with associated thrombosis or "white clot syndrome," patients have paradoxic thromboembolic events while receiving heparin. These events are of acute onset and of major consequence, often resulting in limb loss or death. This paper describes our own experience with ten patients in whom the white clot syndrome occurred during heparin therapy for thrombotic or embolic events. Both porcine and bovine heparin preparations were being given through various routes. In the three cases in which platelet aggregation testing was completed, results were positive. Our ten patients ultimately had a 20% major limb amputation rate and an overall 50% mortality.

The effect of renal function on the pharmacokinetics of gemfibrozil

STUDY OBJECTIVE

to determine the effect of renal function on the pharmacokinetics of gemfibrozil following single and multiple oral doses.

DESIGN

nonrandomized; paired studies of single versus multiple doses.

SETTING

patients enrolled in a veterans hospital renal subspecialty clinic.

PATIENTS

17 male patients 57 to 74 years old selected for various levels of renal function, including end-stage renal disease.

INTERVENTIONS

patients initially received 600 mg of oral-gemfibrozil followed by sequential venous blood sampling. Seven to 14 days later, the patients started receiving gemfibrozil, 600 mg bid. Venous blood samples were obtained over the following 10 days and frequently during a 24-hour washout phase.

MEASUREMENTS AND MAIN RESULTS

peak gemfibrozil concentrations (mg/L) were 11.1 (3.9 SD) for the single dose and 10.2 (3.8) for the multiple-dose study. Time to peak concentration (hr) was 2.1 (1.0) and 1.8 (0.6), respectively. The mean half-life of elimination (hr) from the single-dose study was 6.4 (11.8) compared with the multidose study of 3.0 (3.1), which did not reach statistical significance (P = .25). The difference between the area under the curve for the single versus the multiple-dose study approached statistical significance (P = .054). The coefficient of determination for creatinine renal clearance versus the plasma clearance of oral gemfibrozil was 0.009 (P = .72) for the single-dose regimen and 0.331 (P = .016) for the multiple-dose study.

CONCLUSION

the half-life of gemfibrozil is independent of renal function for both single- and multiple-dose regimens. Dosing schedules do not require alteration for renal insufficiency.

Preterm birth at 23 to 26 weeks' gestation: is active obstetric management justified?

To determine if active perinatal management was justified in preterm deliveries at less than or equal to 26 weeks' gestation, the outcome (survival and short- and long-term morbidity) of 43 infants (group I) born between 23 and 26 weeks' gestation was compared with that of 17 infants (group II) born at 27 weeks' gestation. Of the 12 surviving infants in group I (survival 28%), 11 were ventilated (median = 50 days), eight had moderate to severe bronchopulmonary dysplasia, and four had mild retrolental fibroplasia. At follow-up, two infants had physical disabilities with moderate to severe functional impairment, one had a minor disability, and nine had normal neurodevelopment. In contrast, of the 13 surviving infants in group II (survival 76%), nine were ventilated (median = 8 days), six had moderate to severe bronchopulmonary dysplasia, and six had mild RLF. At follow-up, one infant had a physical disability with moderate to severe functional impairment, four had minor disabilities, and eight had normal development. Perinatal factors that positively influenced survival in the two groups combined included active perinatal management, antenatal steroids, female sex, and absence of clinical chorioamnionitis and asphyxia. Although group I infants had a significantly higher mortality rate (p less than 0.05) and required a longer duration of ventilation (p less than 0.05), no differences in the incidence of postnatal complications or long-term morbidity at 2 to 4 years of age were evident between the two groups.

A standardization of two measures that supplement WISC-R Coding subtest results

Children classified as learning disabled very often show special weakness on the WISC-R Coding subtest. Past research has suggested memory, writing speed, and paired-associate learning rate to be important factors in Coding performance. It is suggested that visual perceptual factors also may be important and that Coding performance in right-handed persons may be especially sensitive to integrity of the left cerebral hemisphere. A measure of writing speed and a large-print version of the WISC-R Coding subtest were administered to 283 children. Norms are provided for these two measures.

The relationship between carbon-dioxide-limited photosynthetic rate and ribulose-1,5-bisphosphate-carboxylase content in two nuclear-cytoplasm substitution lines of wheat, and the coordination of ribulose-bisphosphate-carboxylation and electron-transport capacities

Photosynthesis in two cultivars of Triticum aestivum was compared with photosynthesis in two lines having the same nuclear genomes but with cytoplasms derived from T. boeoticum. The in-vitro specific activity of ribulose-1,5-bisphosphate carboxylase (RuBPCase; EC 4.1.1.39) isolated from lines with T. boeoticum cytoplasm was only 71% of that of normal T. aestivum. By contrast, the RuBPCase activities calculated from the CO2-assimilation rate at low partial pressures of CO2, p(CO2), were the same for all lines for a given RuBPCase content. This indicates that both types of RuBPCase have the same turnover numbers in-vivo of 27.5 mol CO2·(mol enzyme)(-1)·s(-1) (23°). The rate of CO2 assimilation measured at normal p(CO2), p a =340 μbar, and high irradiance could be quantitatively predicted from the amount of RuBPCase protein. The maximum rate of RuBP regeneration could also predict the rate of CO2 assimilation at normal ambient conditions. Therefore, the maximum capacities for RuBP carboxylation and RuBP regeneration appear to be well-balanced for normal ambient conditions. As photosynthetic capacity declined with increasing leaf age, the capacities for RuBP carboxylation and RuBP regeneration declined in parallel.

The specific activity of ribulose-1,5-bisphosphate carboxylase in relation to genotype in wheat

The specific activity of ribulose-1,5-bisphosphate carboxylase (RuBPCase; EC 4.1.1.39) in crude extracts of leaves from euploid, amphiploid and alloplasmic lines of wheat fell into high or low categories (3.75 or 2.70 μmol·mg(-1)·min(-1), 30°C). For the alloplasmic lines, where the same hexaploid nuclear genome was substituted into different cytoplasms, the specific activity of RuBPCase was consistent with the type of cytoplasm (high for the B and S cytoplasms and low for the A and D cytoplasms). There was no evidence from the euploid and amphiploid lines that small subunits encoded in different nuclear genomes influenced the specific activity. High specific activity was conferred by possession of the chloroplast genome of the B-type cytoplasm which encodes the large subunit of RuBPCase. All lines with a cytoplasm derived from the Sitopsis section of wheat, with the exception of Aegilops longissima and A. speltoides 18940, had RuBPCase with high specific activity. In contrast with the euploid lines of A. longissima, the alloplasmic line containing A. longissima cytoplasm from a different source had RuBPCase with high specific activity. The difference in specific activity found here in-vitro was not apparent in-vivo when leaf gas exchange was measured.

Lactic acidosis and beer drinking

A patient is reported who developed lactic acidosis, hyponatraemia and features of the Wernicke-Korsakoff syndrome following long term excessive ingestion of beer and lager. Intramuscular thiamine caused a rapid correction of the lactic acidosis, and the hyponatraemia was corrected by intravenous therapy. On discharge after six weeks of intramuscular Parentrovite the patient still retained some chronic features of the Wernicke-Korsakoff syndrome.

Perinatal listeriosis: report of an outbreak

From April to August, 1981, 15 cases of perinatal listeriosis were seen in Halifax, Nova Scotia, Canada. Nine of the 15 mothers presented with 'flu-like' symptoms, 3 had symptoms of an upper respiratory infection and 2 a history of fever alone. During labor 11 mothers had fevers greater than 38 degrees C and 9 had stained amniotic fluid. Twelve delivered prematurely. Among the 15 infants the most common clinical features were perinatal depression, respiratory distress, fever, hematologic abnormalities and rash. There were 7 deaths (case fatality rate of 46.7%). A transplacental route of infection for the fetus was suggested by the signs of systemic illness in most mothers, the lack of positive maternal vaginal cultures and evidence of chorioamnionitis, premature labor, severe fetal disease and intrauterine death prior to membrane rupture. The delivery of healthy infants to two mothers who had received antepartum treatment for listeriosis suggests that earlier recognition and treatment of maternal disease will improve perinatal outcome.

The relationship between liver function tests and alcohol intake in patients admitted to an alcoholism unit

Values of various blood plasma tests have been determined in heavy drinkers admitted to an Alcoholism Unit and in a reference group of occasional social drinkers. These tests were total protein, albumin, bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), aspartate amino transferase (AST) and amylase. The aim of this study was to assess the reliability and validity of GGT and AST as indices of alcohol intake in heavy drinkers entering an Alcoholism Unit. The data indicate that in the patients group intra-personal variance and analytical variances are relatively small compared with the between-person variance. The data also indicate, however, that in the patients group GGT and AST are not valid group indices of alcohol intake since the between-person variation is large and the correlation with alcohol intake is weak due to large differences in the dose-response relationship between individuals. AST and GGT are poor indicators of alcohol intake in admissions to an Alcoholism Unit.

Differences between Wheat Genotypes in Specific Activity of Ribulose-1,5-bisphosphate Carboxylase and the Relationship to Photosynthesis

The in vitro ribulose-1,5-bisphosphate (RuBP) carboxylase activity per unit of leaf nitrogen was found to be 30% greater in Triticum aestivum than in T. monococcum. This was due to a higher specific activity of the enzyme from T. aestivum, as the amount of RuBP carboxylase protein per unit of total leaf nitrogen did not differ between the genotypes. The occurrence of higher specific activity of RuBP carboxylase is shown to correlate with possession of the large subunit derived from the B genome of wheat.Despite the greater RuBP carboxylase activity per unit of leaf nitrogen in T. aestivum, the initial slopes of curves relating rate of CO(2) assimilation to intercellular p(CO(2)) are similar in T. aestivum and T. monococcum for the same nitrogen content per unit leaf area. The similarity of the initial slopes is the result of a greater resistance to CO(2) transfer between the intercellular spaces and the site of carboxylation in T. aestivum than in T. monococcum.

Auditory-visual and temporal-spatial pattern matching performance of two types of learning-disabled children

Normal readers, learning-disabled readers with a visual processing dysfunction, and learning-disabled readers with an auditory processing dysfunction in grades two through four were compared on the following six pattern-matching tasks: auditory-temporal to visual-spatial (At-Vs), auditory-temporal to visual-temporal (At-Vt), visual-temporal to visual spatial (Vt-Vs), auditory-temporal to auditory-temporal (At-At), visual-temporal to visual-temporal (Vt-Vt), and visual spatial to visual-spatial (Vs-Vs). The results indicated a significant difference between the normal readers and the learning-disabled readers on the At-Vs and At-Vt tasks but not on the Vt-Vs task, which was interpreted in terms of learning-disabled readers being deficient in auditory-visual integration rather than temporal-spatial integration skills. A significant effect of learning disability type was also identified on the Vt-Vt and Vs-Vs tasks but not on the At-At or Vt-Vs tasks. These results were discussed in terms of differences in memory. Implications of the results for previous and future studies were discussed as well as possible practical implications for diagnosing modality strengths and instructing learning-disabled readers.

Factors discriminating pregnancy resolution decisions of unmarried adolescents

Pregnancy resolution decisions of unmarried adolescents were studied with the use of an expected utility decision model that included psychological, background, and economic variables. Discriminant function analysis of the decision to have an abortion or to deliver the child indicated that psychological, background, and economic variables each made significant contributions to the successful classification of teenagers (approximately 87.5% of the women were classified correctly). A four-item Abortion Approval Index, the women's perception of the prospective fathers' abortion opinion, personal knowledge of other unmarried teenagers who delivered, self-reported grade average, and receipt of state financial aid in the form of AFDC or Medicaid payments were the most powerful discriminators. For adolescents who chose to deliver, a second discriminant function indicated that only one economic factor--receipt of state financial aid--successfully discriminated those who married from those who became single mothers (approximately 72% of the women were classified correctly). Results are discussed in terms of possible decision strategies and sequences used by adolescents and the value of using a decision framework that incorporates psychological, background, and economic factors.

Nitrogen and Photosynthesis in the Flag Leaf of Wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L. cv Yecora 70) plants were grown with various concentrations of nitrate nitrogen available to the roots. Sampling of flag leaves began after they had reached full expansion and continued throughout senescence. Rates of gas exchange, ribulose-1,5-bisphosphate (RuP(2)) carboxylase activity, and the amounts of chlorophyll, soluble protein, nitrogen, and phosphorus were determined for each flag leaf. Rate of CO(2) assimilation was uniquely related to total leaf nitrogen irrespective of nutrient treatment, season, and leaf age. Assimilation rate increased with leaf nitrogen, but the slope of the relationship declined markedly when leaf nitrogen exceeded 125 millimoles nitrogen per square meter. Chlorophyll content and RuP(2) carboxylase activity were approximately proportional to leaf nitrogen content. As leaves aged, RuP(2) carboxylase activity and calculated Hill activity declined in parallel. With normal ambient partial pressure of CO(2), the intercellular partial pressure of CO(2) was always such that rate of assimilation appeared colimited by RuP(2) carboxylation and RuP(2) regeneration capacity.The initial slope of rate of CO(2) assimilation against intercellular partial pressure of CO(2) varied nonlinearly with carboxylase activity. It is suggested that this was due to a finite conductance to CO(2) diffusion in the wall and liquid phase which causes a drop in CO(2) partial pressure between the intercellular spaces and the site of carboxylation. A double reciprocal plot was used to obtain an estimate of the transfer conductance.