Thrombotic thrombocytopenic purpura: brain CT and MRI findings in 12 patients

Clinical-neuroimaging analysis of 12 thrombotic thrombocytopenic purpura (TTP) patients revealed a variety of brain lesions. These included reversible cerebral edema lesions with MRI features of reversible posterior leukoencephalopathy syndrome (RPLS). Most of the RPLS patients had hypertension and renal dysfunction, suggesting RPLS due to hypertensive encephalopathy. Prompt treatment usually led to neurologic recovery and disappearance of edematous lesions. Those with infarcts or hematomas had a poorer outcome. TTP should be added to the expanding spectrum of RPLS and hypertensive encephalopathy.     

Intranuclear inclusions in subtypes of striatal neurons in Huntington's disease transgenic mice

R6/2 transgenic mice express exon 1 of an abnormal human Huntington's disease (HD) gene and develop a neurological phenotype similar to HD. These mice develop ubiquitinated neuronal intranuclear inclusions (NII) which might play a central role in the pathophysiology of HD. We studied the distribution of NII in subpopulations of striatal neurons in 12-week-old R6/2 transgenic mice using fluorescent double label immunohistochemistry. We observed that most of the Calbindin-D28K positive projection neurons (89%) and the Parvalbumin positive interneurons (86%) showed ubiquitinated NII. In interneurons, however, which contain either choline acetyltransferase, neuronal nitric oxide synthase, or Calretinin, the frequency of NII was much lower (22%, 8%, 9%, respectively). Our data suggest that subpopulations of striatal neurons differ remarkably in their capability of forming ubiquitinated NII. Interneurons which are known to resist neurodegeneration in HD show less NII.     

Effect of hydrazine upon vitamin B12-dependent methionine synthase activity and the sulphur amino acid pathway in isolated rat hepatocytes

The effect of the industrial chemical, hydrazine (4-12 mM), on methionine synthase (EC 2.1.1.13) activity and levels of the sulphur amino acids homocysteine, cysteine, and taurine as well as GSH were investigated in vitro in isolated rat hepatocyte suspensions and monolayers in order to explain some of the adverse in vivo effects of hydrazine. None of the concentrations of hydrazine were overtly cytotoxic in hepatocyte suspensions (measured as lactate dehydrogenase [LDH] leakage) after 3 hr. However, after 24 hr in culture cells treated with 12 mM, hydrazine showed a significant increase in LDH leakage. Methionine synthase activity was reduced by hydrazine (8 and 12 mM) in suspensions (by 45 and 55%, after 3 hr) and monolayers (12 mM; 65-80% after 24 hr). This was not due to nitric oxide production and the inhibitor of nitric oxide synthase, Nomega-nitro-L-arginine, failed to protect against the hydrazine-induced loss of ATP and GSH and the reduction in urea synthesis at 24 hr. Homocysteine export was increased by 6 mM hydrazine, and total taurine content of treated cells was increased by 12 mM hydrazine. Thus, hydrazine was found to have several important and possibly deleterious effects on some parts of the sulphur amino acid pathway.     

Antibacterial hydroxycinnamic esters from Piper caninum from Paluma, north Queensland, Australia. The crystal and molecular structure of (+)-bornyl coumarate

The crude chloroform bark extract of Piper caninum (Piperaceae) exhibits antibacterial activity against the Gram-positive bacteria, Bacillus cereus, Staphylococcus aureus, and Streptococcus pneumoniae. The antibacterial agents in this extract have been isolated using bioactivity-directed chromatographic techniques and identified by NMR spectroscopy as (+)-bornyl p-coumarate and bornyl caffeate. A single-crystal X-ray structure has been carried out on (+)-bornyl p-coumarate. The compound crystallizes in the orthorhombic space group P2(1)2(1)2(1) (#19) with a = 12.659(4), b = 13.281(4), and c = 10.177(3) A. Fullmatrix least-squares refinement converged at R = 0.047, and Rw = 0.058.     

Effects of various exposure levels of 2-phenylethanol on fetal development and survival in Long-Evans rats

Phenylethanol was given at different levels (432, 43, or 4.3 mg/kg) by gavage to pregnant Long-Evans rats during the "critical period" of organogenesis. Examination of offspring revealed adverse reproductive and teratogenic effects in a dose-related manner. Intrauterine growth retardation occurred at levels of 432 and 4.3 mg/kg. Embryolethality was 18% at 43 mg/kg and 10% at 4.3 mg/kg. Malformations occurred in the following sequence: 100% at 432 mg/kg; 93% at 43 mg/kg, and 50% at 4.3 mg/kg. Noteworthy dose-related teratogenic effects of phenylethanol in offspring manifested themselves in increased incidences of malformed eyes, neural-tube defects, hydronephrosis, and limb defects.     

Health locus of control and self-efficacy beliefs in a healthy elderly sample

BACKGROUND. The elderly are the fastest growing segment of the population, and this will place additional burdens on the healthcare system. It is therefore valuable to study the elderly who have reached their later years relatively free of disease and in good health. METHODS. Health locus of control, self-efficacy beliefs, and lifestyle behaviors were studied in a sample of 57 healthy elderly subjects. Subjects completed the Multidimensional Health Locus of Control Scale, Self-Efficacy Scale, and Healthstyle Self-Test for Seniors. RESULTS. Most of the subjects were characterized by an internal health locus of control belief (91.2%), high generalized self-efficacy (57.9%), and good health behaviors. As hypothesized, positive relationships were found among these variables. DISCUSSION. Individuals with an internal health locus of control and high generalized self-efficacy are more likely to benefit from a health education program than those with an external locus of control and low self-efficacy. Health educators can better serve their clients by evaluating these parameters when developing programs.     

Plasma folate levels in preterm infants,with and without a 1 mg daily folate supplement

One hundred and four preterm infants were studied during the first few months of life in the Special Care Baby Unit of Addenbrooke's Hospital, Cambridge, United Kingdom. Previously, it had been the daily practice within the Unit to give a 1 mg oral supplement of folate (in the form of pteroylglutamic acid), once the infants had commenced full enteral feeding. At least one blood sample was obtained from 70 infants before oral folate supplementation was started. In these, the plasma folate levels fell progressively from a median value of 45 g/l to a median of 12 g/l, by the 2nd–3rd week of life. Once started on the oral supplement, 83 of the infants provided at least one blood sample. The plasma folate level of these infants rose immediately to a median value of 300 g/l and a maximum of 1000 g/l. Within individuals, these plasma folate levels decreased progressively following the introduction of the supplement, despite continuing daily supplementation. In a typical baby this decrease appeared to be explained by an increase in body-size, i.e. dilution of the folate into a larger pool. The implications of this level of supplementation are discussed, and in the light of our observations we suggest that daily supplementation in the range, 0.05–0.2 mg folate may be preferable for well preterm infants.     

Monitoring renal allograft rejection with duplex sonography

Thirty-six renal allograft recipients were monitored by serial duplex Doppler ultrasound studies post-transplant and during early rejection. A separate reproducibility study demonstrated no significant inter- or intra-operator variability in measurements of resistive index of an interlobar artery (RI) (2.1% [1.5%] and 3.2% [2.3%] respectively, mean [standard error] of coefficients of variance). Twenty-one patients had rejection within 3 weeks of transplantation. These grafts showed greater overall rises in the RI, from day 2 to day 5 post-transplant, than the grafts which had no rejection. Eleven of the 21 patients required more than one course of methyl-prednisolone for persistent or recurring rejection. These grafts had higher RI on the day rejection was diagnosed (81 [7.3], median [interquartile range]) compared with the remaining 10 patients (68.6 [8.7]). The 11 grafts with persistent rejection had higher RI (p less than 0.005, Mann-Whitney U-test) on day 2 post-transplant (76 [3.9]) compared with the 10 grafts successfully treated with a single course of methyl-prednisolone (63.2 [10.9]). This study demonstrates that grafts with an RI of greater than 70 on day 2 post-transplant are likely to have rejection requiring additional treatment (sensitivity--100%, specificity--80%). These patients may be candidates for earlier or alternative anti-rejection therapy.     

Possible mechanisms of normal amylase activity in hyperlipemic pancreatitis.

Lipemic serum from three patients with acute pancreatitis and type IV hyperlipemia was fractionated into very-low-density lipoproteins and clear serum. Amylase activity (determined by the Phadebas method) in the component fractions did not exceed that in the original lipemic serum. Addition of these fractions or VLDL and chylomicrons from asymptomatic patients with hyperlipemia to nonlipemic serum from patients with "routine acute pancreatitis" did not inhibit amylase activity or alter the electrophoretic mobility of amylase isoenzymes. Therefore the normal amylase activity often observed in hyperlipemic pancreatitis does not result from an inhibition of amylase activity by serum lipoproteins.