[Peripheral nerve tumors of the thoracic wall: 2 case reports]

The Authors discuss about thoracic wall neoplasms examining in particular neurogenic tumors, their origin, most frequent locations, and biological behaviour. Two cases are reported and preoperative diagnosis as well as surgical techniques and results obtained are discussed.

T cell receptor iota an alternatively spliced product of the T cell receptor zeta gene

It has been previously suggested that three alternative splicings of the murine T cell receptor (TCR) zeta gene are involved in the regulation of TCR/CD3 transduction signals. We here describe a new alternative splicing of this gene (TCR iota), cloned by reverse transcriptase-polymerase chain reaction, that is encoded by exons 1-7 and 10. The protein putatively encoded by TCR iota mRNA differs in its carboxy terminus from that coded by TCR0 as a consequence of the reading frame shift of exon 10. The possible role of this new splicing in TCR modulation is briefly discussed.

[Day surgery and one day surgery in pediatric surgery: personal experience]

The Authors report their experience with 738 children observed and operated for minor diseases in the period January 1989-June 1993. The children were hospitalized for day surgery or one day surgery. After some surgical, anaesthesiological, and postoperative pathophysiological considerations, and on the basis of their results (reduced local and general postoperative complications), the Authors confirm the benefit of this type of organization in terms of reduced nosocomial infections, reduced psychological traumas and increased socio-economic advantages.

Étude caryologique de trois espèces d’Hypochoeris originaires d'Argentine : H. chillensis, H. microcephala var. albiflora et H. megapotamica

Three Hypochoeris species from Argentina with the same chromosome number (x = 4) and similar karyotypes (typically bimodal) show significant ecological and morphological differences. Comparative cytogenetic analysis was done for these taxa, producing karyotypes with correlated idiograms. The number of secondary constrictions and nucleolar organizers varied. The results from this study are discussed in terms of the mechanisms of microevolution within this group of closely related species, and in terms of the evolutionary trend in the genus and in the tribe Cichorieae. Key words: Hypochoeris, Cichorieae, bimodal karyotype, secondary constriction, nucleolar organizer, asymmetry index.

Pharmacokinetic and pharmacodynamic studies following single and multiple doses of rolafagrel, a novel inhibitor of thromboxane synthase, in normal volunteers

The pharmacokinetics and pharmacodynamics of rolafagrel (FCE 22178), a novel thromboxane synthase inhibitor, were evaluated after single and multiple oral doses in eight healthy volunteers. After a single dose (400 mg), the drug was absorbed rapidly, peak plasma concentrations being attained within 2 h in all subjects. Elimination followed a biphasic course, with a rapid initial decline followed after 12-24 h by a late phase with a terminal half-life of about 10 h. About 100% of the administered dose could be recovered in urine within 72 h, mostly in conjugated form. During multiple dosing (400 mg t.i.d. for 5 days), steady-state conditions were approached on day 2 and AUC values over a dosing interval were similar to those observed after a single dose (72.3 vs 76.3 micrograms.ml-1.h). Pharmacokinetic parameters calculated after multiple doses were similar to those observed after a single dose (Cmax: 20.1 vs 18.2 micrograms.ml-1; tmax: 1.2 vs 1.1 h; terminal half-life: 10.9 vs 11.4 h; CL: 85.2 vs 70.4 ml.h-1.kg-1; V: 1.23 vs 1.24 l.kg-1). Platelet generation of thromboxane B2, the stable breakdown product of thromboxane A2, was inhibited by 85% at a plasma rolafagrel concentration of about 4 micrograms.ml-1, and only a small increase in inhibition was observed at higher concentrations.

Pattern of cytokine gene expression in brains of mice protected by picolinic acid against lethal intracerebral infection with Candida albicans

Recently, we demonstrated that intracerebral (i.c.) administration of picolinic acid (PLA) confers protection against a lethal local challenge with the opportunistic pathogen Candida albicans. By histopathological studies, we show here that mice receiving PLA treatment survive challenge and no evidence of fungal invasion is found within the brain compartment. In contrast, PLA-untreated mice succumb to infection within 7-10 days and show massive brain colonization with extensive granulomatous reaction. By PCR analysis, we show that, unlike naive brains, PLA-treated brains show transient activation of TNF alpha, IL-1 beta and IL-6 genes. C. albicans infection results in high levels of all cytokine transcripts, the phenomenon being long-lasting in PLA-untreated brains, while gradually declining in PLA-treated brains. The only exception is IL-1 beta, whose levels remain high at the latest time-points tested, also in PLA-treated brains. Finally, IL-1 alpha, constitutively detectable in naive brains, is slightly enhanced by C. albicans challenge, regardless of prior treatment. These findings, together with the knowledge that PLA is a potent co-stimulus for macrophages, suggest the involvement of cytokine circuits, likely of macrophage origin, in anti-Candida resistance established by PLA at the cerebral level.

Omeprazole does not enhance the metabolism of phenacetin, a marker of CYP1A2 activity, in healthy volunteers

Omeprazole has been reported to increase cytochrome P450IA2 (CYP1A2) activity in vitro, but whether this effect also occurs in vivo is controversial. To clarify this issue, the effect of omeprazole (20 mg/day for 8 days) on the kinetics and metabolism of phenacetin, an in vivo marker of CYP1A2 activity, was examined in 10 healthy volunteers. The pharmacokinetic parameters of phenacetin and metabolically derived paracetamol on the 8th day of omeprazole administration were very similar to those observed in a control session in the absence of omeprazole administration, the only significant difference being a higher peak plasma phenacetin concentration during omeprazole treatment. It is concluded that at the dosage used omeprazole does not increase the rate of oxidative and conjugative reactions involved in the metabolism of phenacetin and paracetamol respectively. These data are consistent with the hypothesis that omeprazole is generally devoid of inducing effects on CYP1A2 activity in vivo, at least in a Caucasian population with a low prevalence of the omeprazole-mephenytoin poor metabolizer phenotype.

Tumor necrosis factor as an autocrine and paracrine signal controlling the macrophage secretory response to Candida albicans

We have previously demonstrated that the hyphal form of Candida albicans (H-Candida), but not the yeast form (Y-Candida), acts as a macrophage-stimulating agent. The early response (1 to 3 h) of the macrophage cell line ANA-1 to H-Candida results in enhanced tumor necrosis factor (TNF) transcription and production. Here we show that when coincubation times are prolonged (3 to 24 h), Y-Candida also exhibits stimulatory properties. This phenomenon has been ascribed to the occurrence of the dimorphic transition, as demonstrated by microscopic evaluation of the cultures and by experiments in which both killed Y-Candida and the agerminative strain C. albicans PCA-2 failed to induce cytokine production. TNF produced in response to H-Candida acts as an autocrine and paracrine signal controlling the macrophage secretory response to C. albicans. In fact, addition of anti-TNF polyclonal antibodies to the coculture of ANA-1 macrophages and H-Candida results in a marked and time-dependent decrease of TNF transcript levels. Moreover, pretreatment of macrophages with recombinant TNF for 3 h enhances TNF and induces interleukin-1 production in response to both forms of Candida, while pretreatment for 18 h renders macrophages refractory to any stimuli. Interestingly, the kinetics of interleukin-1 transcription and secretion in response to H-Candida are delayed with respect to those of TNF. Overall, these data indicate that TNF, produced by macrophages in response to H-Candida, regulates its own production as well as that of other soluble factors, thus suggesting that this cytokine plays multiple roles in the immune mechanisms involved in Candida infection.

CYP2D6-related oxidation polymorphism in Italy

The distribution of the oxidation polymorphism related to cytochrome CYP2D6 (debrisoquine type) was determined in 246 healthy Italian volunteers. Phenotyping was based on HPLC determination of the dextrometorphan/dextrorphan concentration ratio (metabolic ratio) in urine samples collected over an 8 h interval following a single oral 30 mg dose of dextromethorphan hydrobromide. Urinary excretion of dextromethorphan showed a wide interindividual variability, ranging from < or = 0.04 to 3.9% and from 0.5 to 79.6% of the dose, respectively. Metabolic ratios ranged from < or = 0.001 to 6.6. Eleven of the 246 subjects showed a metabolic ratio greater than 0.30, indicating that 4.5% of the population could be ascribed to the poor metabolizer status. The frequency of the poor metabolizer phenotype in this population is within the range described for other Caucasian ethnic groups.

Heterogeneous secretory response of phagocytes from different anatomical districts to the dimorphic fungus Candida albicans

In the present study, we have examined the ability of phagocytes from different anatomical districts to discriminate between the two morphogenetic forms of Candida albicans. We have demonstrated that resident peritoneal macrophages (RP-M phi) and thioglycollate-elicited peritoneal macrophages (TP-M phi) were able to distinguish between the hyphal (H-Candida) and the yeast (Y-Candida) form of the fungus, since TNF production was observed only upon exposure of RP-M phi and TP-M phi to H-Candida. In contrast, splenic macrophages (S-M phi), bone marrow-derived macrophages (BM-M phi) and polymorphonuclear neutrophils (PMN) did not discriminate between the two forms because S-M phi and PMN produced TNF regardless of the morphogenetic status of the fungus, while BM-M phi did not. Under the same experimental conditions, we failed to observe IL-1 production from any of the phagocytic cell populations examined, with the exception of PMN. This implies that the interaction between phagocytes and C. albicans triggers differential secretory responses depending upon the morphogenetic status of the fungus and the anatomical localization of the immune cells.

Vigabatrin-induced decrease in serum phenytoin concentration does not involve a change in phenytoin bioavailability

The possibility that vigabatrin (VGB) decreases serum phenytoin (PHT) concentration by lowering the oral bioavailability of PHT was investigated in 21 patients with epilepsy. Each patient was switched from oral to intravenous PHT for 5 days before and after combined treatment with VGB. After VGB (2-3.5 g day(-1) for at least 5 weeks), serum PHT concentrations decreased slightly from 87 +/- 25 to 76 +/- 31 micromol l(-1) (means +/- s.d., P < 0.05), but in a subgroup of seven patients the decrease was more prominent (from 72 +/- 22 to 49 +/- 17 micromol l(-1), P < 0.005). At baseline (before VGB), serum PHT remained unaffected (85 +/- 30 micromol l(-1)) after switching PHT dosage to the intravenous route, indicating that the oral availability of the drug was virtually complete. During VGB treatment, serum PHT was also unchanged (74 +/- 34 micromol l(-1)) after switching from oral to intravenous therapy, and this was also true for the subgroup of patients showing a prominent interaction (48 +/- 18 micromol l(-1)). The urinary recoveries of PHT and its metabolites pHPPH and mHPPH remained constant throughout the study. It is concluded that the oral availability of PHT is unaffected by VGB and that the VBG-induced decrease in serum PHT is mediated by alternative mechanisms.

The pharmacokinetics of oxcarbazepine and its active metabolite 10-hydroxy-carbazepine in healthy subjects and in epileptic patients treated with phenobarbitone or valproic acid

The kinetics of oxcarbazepine (OXC) and its active metabolite 10-hydroxy-carbazepine (10-OH-CZ) after a single oral OXC dose (600 mg) were compared in healthy control subjects and in epileptic patients treated with phenobarbitone or sodium valproate (n = 8 in each group). In all groups, serum 10-OH-CZ concentrations were much higher than those of the parent drug. In patients on valproate, the kinetics of OXC and 10-OH-CZ did not differ significantly from those observed in controls. In patients on phenobarbitone, AUC values of both OXC and 10-OH-CZ were lower than in controls (2.9 +/- 0.4 vs 5.1 +/- 0.7 microg ml(-1) h and 89 +/- 7 vs 119 +/- 10 microg ml(-1) h respectively, means +/- s.e. mean, P < 0.05), whereas 10-OH-CZ half-lives were only marginally shorter (17 +/- 1 h vs 20 +/- 2 h, NS). These data indicate that the biotransformation of OXC and 10-OH-CZ may be accelerated by concomitant treatment with phenobarbitone but that the magnitude of this effect is unlikely to be of great clinical significance.

Neuropsychological abnormalities in AIDS and asymptomatic HIV seropositive patients

Neuropsychological and immunological parameters were studied in 36 AIDS patients with early disease and without clinical, laboratory, and neuroradiological signs of CNS impairment, and also in 33 asymptomatic HIV seropositive subjects. Many AIDS patients performed abnormally on timed psychomotor tasks, tasks involving sequencing and "set-shifting", and memory tasks stressing attention, learning, active retrieval, and monitoring of information. Asymptomatic HIV seropositive subjects as a group did not perform significantly worse than controls. However, on the basis of a cut off number of pathological performances on neuropsychological tasks, 52.8% of AIDS and 30.3% of asymptomatic HIV seropositive subjects had cognitive impairment, compared with 3.9% of HIV seronegative controls. Low values of CD4+ cells and of CD4+/CD8+ ratio and high titres of P-24 antigen in the blood prevailed among subjects with cognitive impairment, especially in the asymptomatic HIV seropositive group.

Candida albicans hyphal form enhances tumor necrosis factor mRNA levels and protein secretion in murine ANA-1 macrophages

We have demonstrated that Candida albicans in its hyphal form (H-Candida) acts as a stimulating agent in the cloned macrophage population ANA-1. Both tumor necrosis factor (TNF) mRNA levels and secreted biological activity augment in ANA-1 macrophages exposed to H-Candida. Such effects are observed at an effector-to-target cell ratio of 1:1 and occur after 1 and 3 hr of coincubation, respectively. The phenomenon is independent of the metabolic status of the fungus, since viable as well as heat-killed H-Candida are comparable in inducing TNF mRNA levels. The extent and kinetics of H-Candida-mediated effects are similar to those observed following exposure of ANA-1 macrophages to lipopolysaccharide (LPS). This implies that C. albicans in its hyphal form is a potent macrophage modulator; whether it acts through the same mechanism(s) as LPS remains to be elucidated.

Intracerebral transfer of an in vitro established microglial cell line: local induction of a protective state against lethal challenge with Candida albicans

An in vitro generated BV-2 microglial cell line has been transferred intracerebrally into syngeneic immunocompetent mice prior to local challenge with Candida albicans. The transfer resulted in the establishment of local protection against a lethal dose of C. albicans, which was accompanied by an impairment of yeast growth in the brain and kidneys. Upon histological examination of brain sections from BV-2 cell-pretreated mice, it was found that the size and number of granulomas was reduced as compared to untreated controls receiving Candida alone. These observations provide direct evidence that microglia play a crucial role in the local defense against intracerebral infections.

A rapid objective immunofluorescence microassay. Application for detection of surface and intracellular antigens

An indirect immunofluorescence microassay, which permits automated reading, has been employed for simple, rapid and objective detection of surface and intracellular antigens. Initially, the cells, spun in microplates, are fixed with glutaraldehyde (0.25% v/v in PBS). Following fixation, the cells can be stored at 4 degrees C for up to 2 weeks before being used in the immunofluorescence microassay. The fixed cells are then stained according to standard procedures using appropriate first and fluorescein-conjugated second antibodies. An automated and quantitative evaluation of the fluorescence intensity of the cell samples was achieved using the Titertek Fluoroskan II automatic reader. This microassay was shown to be suitable for the detection of the surface MAC1 antigen and intracellular v-myc protein in the GG2EE macrophage cell line.

Multiple sclerosis. Magnetic resonance imaging, evoked potentials and cerebrospinal fluid analysis

We have studied 27 patients with multiple sclerosis (22 definite, 5 probable) by magnetic resonance imaging (MRI), visual evoked potentials (VEPs), brainstem auditory evoked potentials (BAEPs), and oligoclonal bands (OBs) in cerebrospinal fluid (CSF), MRI was altered in 92.5% of the cases, the presence of OBs in CSF was revealed in 73.1% of the examined patients, the frequency of evoked potentials (EPs) alteration was VEPs = 59.3% and BAEPs = 29.6%, at least one of the two EPs occurred positive in 66.6% of the cases. Our data confirm the more sensitive value of MRI compared with OBs and EPs studies in assessing MS, and stress the utility of the combined use of these tests.

Comparative in vitro activity of imipenem against gram-positive and gram-negative aerobic bacteria from clinical isolates

Imipenem is a member of a new class of beta-lactam antibiotics, carbapenems, with a very broad antibacterial spectrum. In this work we evaluated the in vitro activity of imipenem against a variety of bacterial strains isolated from clinical specimens as well as the activity of other beta-lactam antibiotics. The results obtained with 501 bacterial strains show that imipenem is active on both gram-negative and gram-positive microorganisms isolated from different infections. The in vitro inhibitory activity is greater than that of aztreonam, cefotaxime, ceftriaxone, piperacillin, amikacin, and netilmicin, against the majority of strains tested.

The clinical significance of elevated CSF and plasma histamine in cerebral aneurysm surgery utilizing cardiopulmonary bypass with total circulatory arrest

Recently there has been a renewed interest in the neurosurgical treatment of large cerebral aneurysms and AV malformations utilising cardiopulmonary bypass (CPB) and total circulatory arrest (TCA). However, the differing tolerance limits of coagulation and bleeding, pH control and fluid constraint are difficult to reconcile. Although clinical assessment, electro encephalogram (EEG) and intracranial pressure-monitoring assist in identification of cerebral damage, CPB and TCA inflict their own penalties with resultant uncertainty in post-operative neurological evaluation, and producing difficulties in interpretation and management. Additionally, an unanswered question is, to what extent the known cardiac and cerebral effects of circulating histamine might influence the post-circulatory arrest recovery in these patients, and whether this would further compromise the neurological result. We report our experience of 9 such cases who underwent this procedure, and were able to achieve a satisfactory neurological result in 7 patients with differing lesions. During the operation both CSF (from the open cranium) and blood (from the right internal jugular vein) were sampled at intervals for subsequent plasma histamine estimation. Despite markedly elevated histamine levels during CPB and TCA, this was not associated with an unfavourable neurological outcome. These early findings have given us encouragement to the useful role of CPB and TCA in these complex neurosurgical presentations, and raise interesting questions about the clinical importance of histamine-evoked cerebral ischaemia that has been demonstrated in experimental models.