Influence of aging on thromboxane A2 and prostacyclin levels in rat hippocampal brain slices

We have investigated the influence of age (3, 18, 24 months) on Thromboxane A₂ (TXA₂) and Prostacyclin (PGI₂) levels in hippocampal slices from F344/NHSD rats. A significant increase in TXA₂ and PGI₂ levels was observed in 18 and 24 months old compared to 3 months old animals. A significant reduction in the ratio TXA₂/PGI₂ produced by a higher increase in PGI₂ was observed in 24 month old animals. The reduction in the TXA₂/PGI₂ ratio has been related to vasodilatory and antiaggregating effects that may contribute to protect the brain against neuronal damage.     

Penicillium peritonitis in an adolescent receiving chronic peritoneal dialysis

A 19-year-old female on chronic peritoneal dialysis developed acute peritonitis; multiple peritoneal fluid and catheter tip cultures yielded Penicillium species. She promptly responded to catheter removal and intravenous amphotericin B, followed by oral fluconazole, without further recurrences 1 year later. This is the first reported case of Penicillium peritonitis in the pediatric population. We review the microbiology and clinical spectrum of this disease, as well as the few previous reported cases in adults. Received: 2 November 1998 / Revised: 1 February 1999 / Accepted: 4 February 1999     

Selective inhibitors of glial GABA uptake: synthesis, absolute stereochemistry, and pharmacology of the enantiomers of 3-hydroxy-4-amino-4,5,6,7-tetrahydro-1,2-benzisoxazole (exo-THPO) and analogues

3-Methoxy-4,5,6,7-tetrahydro-1,2-benzisoxazol-4-one (20a), or the corresponding 3-ethoxy analogue (20b), and 3-chloro-4,5,6, 7-tetrahydro-1,2-benzisothiazol-4-one (51) were synthesized by regioselective chromic acid oxidation of the respective bicyclic tetrahydrobenzenes 19a,b and 50, and they were used as key intermediates for the syntheses of the target zwitterionic 3-isoxazolols 8-15 and 3-isothiazolols 16 and 17, respectively. These reaction sequences involved different reductive processes. Whereas (RS)-4-amino-3-hydroxy-4,5,6,7-tetrahydro-1,2-benzisoxazole (8, exo-THPO) was synthesized via aluminum amalgam reduction of oxime 22a or 22b, compounds 9, 11-13, and 15-17 were obtained via reductive aminations. Compound 10 was synthesized via N-ethylation of the N-Boc-protected primary amine 25. The enantiomers of 8 were obtained in high enantiomeric purities (ee >/= 99.1%) via the diastereomeric amides 32 and 33, synthesized from the primary amine 23b and (R)-alpha-methoxyphenylacetyl chloride and subsequent separation by preparative HPLC. The enantiomers of 9 were prepared analogously from the secondary amine 27. On the basis of X-ray crystallographic analyses, the configuration of oxime 22a was shown to be E and the absolute configurations of (-)-8 x HCl and (+)-9 x HBr were established to be R. The effects of the target compounds on GABA uptake mechanisms in vitro were measured using a rat brain synaptosomal preparation and primary cultures of mouse cortical neurons and glia cells (astrocytes). Whereas the classical GABA uptake inhibitor, (R)-nipecotic acid (2), nonselectively inhibits neuronal (IC(50) = 12 microM) and glial (IC(50) = 16 microM) GABA uptake and 4,5,6,7-tetrahydroisoxazolo?4,5-cpyridin-3-ol (1, THPO) shows some selectivity for glial (IC(50) = 268 microM) versus neuronal (IC(50) = 530 microM) GABA uptake, exo-THPO (8) was shown to be more potent as an inhibitor of glial (IC(50) = 200 microM) rather than neuronal (IC(50) = 900 microM) GABA uptake. This selectivity was more pronounced for 9, which showed IC(50) values of 40 and 500 microM as an inhibitor of glial and neuronal GABA uptake, respectively. These effects of 8 and 9 proved to be enantioselective, (R)-(-)-8 and (R)-(+)-9 being the active inhibitors of both uptake systems. The selectivity of 9 as a glial GABA uptake inhibitor was largely lost by replacing the N-methyl group of 9 by an ethyl group, compound 10 being an almost equipotent inhibitor of glial (IC(50) = 280 microM) and neuronal (IC(50) = 400 microM) GABA uptake. The remaining target compounds, 11-17, were very weak or inactive as inhibitors of both uptake systems. Compounds 9-13 and 15 were shown to be essentially inactive against isoniazide-induced convulsions in mice after subcutaneous administration. The isomeric pivaloyloxymethyl derivatives of 9, compounds 43 and 44, were synthesized and tested as potential prodrugs in the isoniazide animal model. Both 43 (ED(50) = 150 micromol/kg) and 44 (ED(50) = 220 micromol/kg) showed anticonvulsant effects, and this effect of 43 was shown to reside in the (R)-(+)-enantiomer, 45 (ED(50) = 44 micromol/kg). Compound 9 also showed anticonvulsant activity when administered intracerebroventricularly (ED(50) = 59 nmol).     

Neuroleptic malignant syndrome in a patient with head injury

Neuroleptic malignant syndrome is an idiosyncratic reaction associated with the use of neuroleptic drugs. We report a case of this rare syndrome in a head injury patient associated with some unusual features: rhabdomyolysis with a high level of creatine kinase, the development of acute renal failure, the early use of continuous venovenous haemofiltration in treatment and rigidity that was refractory to conventional treatment with dantrolene and bromocriptine. The diagnosis in patients with multiple injuries must be based on a high index of suspicion.     

Validation of a quality of life questionnaire for critically ill patients

Objective Development and validation of quality of life questionnaire for critical care patients.Design Prospective study.Setting Intensive care unit (ICU) of a general hospital and ICUs of 83 Spanish hospitals.Sample Patients admitted to the ICU>18 years of age; close family members.Method A committee of experts designed a questionnaire with characteristics judged essential for intensive care use: easy, quick administration (5–10 min); capable of completion by patient or close family member, by direct or telephone interview. Fifteen items relevant to critical care patients were grouped in three subscales: basic physiological activities, normal daily activities, and emotional state. Reproducibility of interobserver, intraobserver, patient/family member and telephone/direct interviews was analysed and also internal consistency, responsiveness, and main components.Results Internal consistency (578 patients): Cronbach's alpha coefficient=0.85. Reproducibility: intraobserver reproducibility (n=150): Spearman correlation coefficient=0.92. Interobserver (n=85); correlation=0.92. Patient/family member (n=81): correlation=0.92. Telephone/direct interview (n=54): correlation=0.96. Validity: factorial analysis confirmed that the three subscales were fundamental questionnaire components. There was good concordance between questionnaire/subscale and Glasgow Outcome Scale (GOS) results. Responsiveness: quality of life score changes between preadmission and 6 months' postdischarge correlated with GOS findings (weighted kappa index=0.56).Conclusions Questionnaire meets objectives recommended for critical care use, and fulfills essential requirements of validity and reproducibility when applied to critically ill patients.This study forms part of the PAEEC (Project for the Epidemiological Analysis of Critical Care Patients), and was supported by a grant from the Fondo de Investigaciones Sanitarias (F.I.S.-91/0703), and by the Granada University Research Group (Number 3244)