[Seasonal blood pressure changes in mild hypertension]

BACKGROUND

Our goal was to evaluate seasonal blood pressure (BP) changes in patients with mild hypertension.

PATIENTS AND METHOD

Forty-three hypertensive subjects underwent two clinical examinations in different seasons (summer and winter), separated by a 6 month-interval.Each examination included a 24 h ambulatory BP monitoring.

RESULTS

Ambulatory diurnal BP was higher in winter that it was in summer(p < 0.01). Seasonal changes were inversely correlated to the body mass index (r = -0.44; p < 0.05, for systolic BP).

CONCLUSIONS

Ambulatory diurnal BP is subjected to seasonal influences. Seasonal variations of BP habe implications for the clinical management of hypertension.

Pharmacokinetics and residues of ciprofloxacin and its metabolites in broiler chickens

The pharmacokinetic properties of ciprofloxacin and its metabolites were determined in healthy chickens after single i.v. and oral dosage of 8 mg ciprofloxacin kg(-1) bodyweight. After i.v. and oral administration, the plasma concentration-time graph was characteristic of a two-compartment open model. Mean (SD) elimination half-life and mean residence time of ciprofloxacin in plasma were 8.84 (2.13) and 8.54 (1.64) hours, respectively, after i.v. administration and 11.89 (1.95) and 13.32 (2.65) hours, respectively, after oral administration. Mean maximal plasma concentration of ciprofloxacin was 2.63 (0.20) microg ml(-1), and the interval from oral administration until maximum concentration was 0.36 (0.07) hours. The mean oral bioavailability of ciprofloxacin was found to be 69.12 (6.95) per cent. Ciprofloxacin was mainly converted to oxociprofloxacin and desethyleneciprofloxacin. Considerable kidney, liver, muscle and skin + fat tissue concentrations of ciprofloxacin and its metabolites oxociprofloxacin and desethyleneciprofloxacin were found when ciprofloxacin was administered orally (8 mg kg(-1) on 3 successive days). It was estimated that mean tissue concentrations of ciprofloxacin and its metabolites ranging between 0.011 to 0.75 microg g(-1) persisted for 5 days.

Scientific basis and regulatory aspects for the toxicology of plant protection products in the European Union

Authorization of plant protection products/agrochemicals/pesticides in the European Union is done on the basis of their toxicological properties. This paper reviews the current legislation for placing an agrochemical on the market (ie a new substance or a existing active substance), and the toxicology studies needed for inclusion of a substance in any of the annexes of the Council Directive of the European Economic Community 91/414/ EEC. Risk analysis and its steps is discussed. The "threshold toxicity" employed to allow risk characterisation of plant protection products is described, such as acceptable daily intake, acceptable operator exposure level, acute reference dose, and maximum admissible concentration in water.

Toxicity and hazardous properties of solvent base adhesive wastes

In this work, the hazardous properties of solvent base adhesive wastes generated in the footwear manufacturing process have been studied. The characterisation procedures and criteria used are those contained in the legal documents European Union Council Decision 94/904/CE and October 13th Spanish Ministerial Order. The properties studied were the following: flash point, reactivity (gas generation), ecotoxicity, main contaminants extracted by the leaching process and main harmful substances contained in wastes. An additional study of the relationship between flash point and solvent concentration in waste was carried out for polyurethane-acetone and neoprene-toluene systems. The wastes considered were metal containers with remains of dry or semi-dry adhesive. The results obtained show that the presence of solvent in wastes confers on them hazardous characteristics (flash point and harmful composition) depending on the solvent type and its concentration.

Diabetes abolishes the gender difference in vasopressin-mediated potentiation of sympathetic vasoconstriction

Electrical field stimulation (4 Hz, 0.2 ms pulse duration, at a supramaximal voltage of 70 V, for 1 s) of isolated rat tail artery segments produced contraction which was lower in female than in male rats, and was reduced by streptozotocin-induced diabetes in both genders. This contraction was potentiated by vasopressin (10(-12)-10(-10) M) more in normoglycemic male than in normoglycemic female rats, and this effect of vasopressin was increased by the cyclooxigenase inhibitor meclofenamate (10(-5) M) in female control rats, but not in diabetic female, or control and diabetic male rats, and it was not modified by the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M). Endothelin-1 (10(-10)-3 x 10(-9) M) also potentiated the contraction to electrical stimulation. This potentiation was similar in all experimental groups, and it was not modified by meclofenamate or L-NAME. These results suggest that the potentiating effect of vasopressin, but not that of endothelin-1, on the sympathetic vasoconstriction, is lower in females than in males, probably by an increased release of vasodilating prostanoids, and this release may be reduced by diabetes in females.

Clinical features and long-term outcome of obesity-associated focal segmental glomerulosclerosis

BACKGROUND

Several cases of obesity-associated focal segmental glomerulosclerosis (OB-FSG) have been reported but little is known about the clinico-pathological features of this entity and its long-term outcomes.

METHODS

We studied 15 obese patients (BMI 35+/-5.2 kg/m(2)) with biopsy-proven FSG. They were compared with a control group of 15 non-obese patients with idiopathic FSG (I-FSG).

RESULTS

Mean proteinuria at the time of renal biopsy was 3.1+/-2 g/24 h in OB-FSG; it reached the nephrotic range (> or =3.5 g/24 h) during follow-up in 12 patients (80%), but none of them had oedema, hypoproteinaemia, or hypoalbuminaemia. Proteinuria was more marked amongst I-FSG (6.5+/-4.2 g/24 h) and most of them developed oedema and biochemical nephrotic syndrome. Glomerulomegaly was observed in all renal biopsies from OB-FSG patients (mean glomerular diameter 256+/-24 microm in OB-FSG vs 199+/-26 microm in I-FSG, P<0.001). Twelve OB-FSG patients (80%) were treated with ACE inhibitors (ACEI) and proteinuria significantly decreased within the first 6 months of treatment but showed a later increase. None of the obese patients achieved a sustained weight loss. Seven (46%) patients with OB-FSG experienced a progressive renal insufficiency and five of them started intermittent dialysis. Kaplan-Meier estimated probabilities of renal survival after 5 and 10 years were 77 and 51%, respectively, in OB-FSG patients, and 52 and 30% in I-FSG (P<0.05). The risk of developing progressive renal failure among OB-FSG patients was statistically correlated with serum creatinine and creatinine clearance at presentation.

CONCLUSIONS

OB-FSG indicates a poor prognosis with almost one-half of patients developing advanced renal failure. Knowledge of the clinico-pathological features of this entity (obesity, FSG lesions with glomerulomegaly, absence of nephrotic syndrome despite nephrotic-range proteinuria) should be helpful in establishing an accurate and early diagnosis.

Adrenergic vasoconstrictor activity in the cerebral circulation after inhibition of nitric oxide synthesis in conscious goats

The interaction between nitric oxide (NO) and adrenergic activity in the cerebral circulation was studied using conscious goats, where blood flow to one brain hemisphere (cerebral blood flow) was electromagnetically measured, and the effects of phentolamine and hexamethonium on cerebrovascular resistance were evaluated before (control) and after inhibition of NO synthesis with NW-nitro-L-arginine methyl ester (L-NAME). L-NAME (12 goats, 40 mg kg(-1) administered i.v.) reduced cerebral blood flow from 62 +/- 3 to 44 +/- 2 ml min(-1), increased mean systemic arterial pressure from 100 +/- 3 to 126 +/- 4 mm Hg, decreased heart rate from 79 +/- 5 to 50 +/- 4 beats min(-1) and increased cerebrovascular resistance from 1.63 +/- 0.08 to 2.91 +/- 0.016 mm Hg ml(-1)min(-1) (all P < 0.01). These hemodynamic variables normalized 48-72 h after L-NAME administration. Phentolamine (six goats, 1 mg), injected into the cerebral circulation. increased cerebral blood flow without changing systenic arterial pressure, but its cerebrovascular effects were augmented for about 24 h after L-NAME. The decrements in cerebrovascular resistance induced by phentolamine, in mm Hg ml(-1) min(-1), were: under control, 0.42 +/- 0.05; immediately after L-NAME, 1.38 +/- 0.09 (P < 0.01 compared with control); by about 24 h after L-NAME, 0.71 +/- 0.09 (P < 0.05 compared with control); and by about 48 h after L-NAME, 0.40 +/- 0.07 (P > 0.05 compared with control). Hexamethonium (six goats, 0.5-1 mg kg(-1) min(-1) i.v.) decreased mean systemic arterial pressure to about 75 mm Hg and caused tachycardia similarly before and after L-NAME, but the decrements in cerebrovascular resistance were augmented for about 24 h after L-NAME. The decrements in cerebrovascular resistance induced by hexamethonium, in mm Hg ml(-1).min(-1), were: under control. 0.61 +/- 0.09, immediately after L-NAME, 1.33 +/- 0.16 (P < 0.01 compared with control); by about 24 h after L-NAME, 1.18 +/- 0.10 (P < 0.01 compared with control): and by about 48 h after L-NAME, 0.99 +/- 0.10 (P > 0.05 compared with control). Therefore, these results suggest that adrenergic vasoconstrictor tone in cerebral vasculature may be augmented after inhibition of NO synthesis, and that this increment may contribute to the reduction of cerebral blood flow after inhibition of NO formation.

Bacterial and viral etiology of acute otitis media in Chilean children

BACKGROUND

Acute otitis media (AOM) is a main cause for antimicrobial prescription in Latin America. Pathogen diversity in different geographic regions underscores the need for updated knowledge on AOM microbiology.

AIM

To prospectively determine the role of bacteria and viruses in Chilean children with AOM.

METHODS

Between July, 1998, and June, 1999, children >3 months with a presumptive diagnosis of AOM were referred to the study ear, nose and throat physician. Middle ear fluid and nasopharyngeal aspirates were obtained from children with confirmed AOM and processed for common bacteria, Mycoplasma pneumoniae, Chlamydia pneumoniae and viruses. Antimicrobial susceptibility patterns and serotypes of Streptococcus pneumoniae strains were determined.

RESULTS

An ear, nose and throat physician confirmed diagnoses for 222 (42%) of 529 children referred with diagnosis of AOM, and 170 children met eligibility criteria for the study. One or more pathogens were detected in 140 of 170 (82%) children. Predominant bacteria were S. pneumoniae (37%), Haemophilus influenzae (24%) and Streptococcus pyogenes (13%). M. catarrhalis was detected in 2 children, C. pneumoniae was found in 1 and M. pneumoniae was not detected. Viruses were detected in 22 children (13%) from nasopharyngeal aspirates, and in 6 of them the same virus was detected in middle ear fluid. Penicillin-resistant (intermediate and high) S. pneumoniae represented 40% of isolates and 10% of H. influenzae were beta-lactamase producers. All 10 penicillin-resistant S. pneumoniae strains were resistant to cefuroxime. Eighteen S. pneumoniae serotypes were detected and 19F was associated with high level penicillin resistance.

CONCLUSION

This study can impact local management of AOM, and it should encourage continuous surveillance of AOM microbiology in Chile and other developing countries.

Cerebral vasoconstriction produced by vasopressin in conscious goats: role of vasopressin V(1) and V(2) receptors and nitric oxide

To examine the role of vasopressin V(1) and V(2) receptors, nitric oxide and prostanoids in the cerebrovascular effects of arginine vasopressin, cerebral blood flow was electromagnetically measured in awake goats. In 16 animals, vasopressin (0.03 - 1 microg), injected into the cerebral circulation, caused increments of resting cerebrovascular resistance which ranged from 18% (0.03 microg, P<0.01) to 79% (1 microg, P<0.01). Desmopressin (0.03 - 1 microg, four goats) did not affect significantly cerebrovascular resistance. The cerebrovascular resistance increases by vasopressin were reduced significantly by the antagonist for vasopressin V(1) receptors d(CH(2))(5)Tyr(Me)-AVP in a rate depending way (five (six goats) and 15 (four goats) microg min(-1)), and by the mixed antagonist for vasopressin V(1) and V(2) receptors desGly-d(CH(2))(5)-D-Tyr(Et)Val-AVP (5 microg min(-1), four goats), and they were not significantly affected by the antagonist for vasopressin V(2) receptors d(CH(2))(5), D-Ile(2), Ile(4)-AVP (5 microg min(-1), four goats). The inhibitor of nitric oxide synthesis N(w)-nitro-L-arginine methyl ester (L-NAME, 47 mg kg(-1) i.v., five goats) augmented cerebrovascular resistance by 130% (P<0.01), and for 24 h after this treatment the cerebrovascular effects of vasopressin were potentiated. The inhibitor of cyclo-oxygenase meclofenamate (6 mg kg(-1) i.v., five goats) did not modify significantly resting haemodynamic variables measured or the cerebrovascular effects of vasopressin. Therefore, the vasopressin-induced cerebral vasoconstriction may be mediated by vasopressin V(1) receptors, without involvement of vasopressin V(2) receptors, and may be modulated by nitric oxide but not by prostanoids.

Absence of genetic diversity reduction in the HIV-1 integrated proviral LTR sequence population during successful combination therapy

We report the integrated proviral LTR sequence variation in four patients on highly active antiretroviral therapy (HAART). Integrated proviral fragments of LTR taken from four time points were PCR amplified from PBMCs and 10 to 12 individual clones were sequenced for each time point. Intrasample genetic distances and phylogenetic reconstruction of all LTR sequences demonstrated that 1-2 years of successful HAART did not significantly reduce the genetic repertoire of the integrated reservoir of HIV-1.

Leaching of toluene-neoprene adhesive wastes

This work consists of the study of the extraction of solvent (toluene) from a polymeric (neoprene) substrate during a leaching process. Total organic carbon (TOC) is the main contaminant parameter in the leaching of these systems due to the solution of the toluene and the dispersion of the polymer. The toxicity of the extracts was measured with a Microtox equipment, using Photobacteria phosphoreum, deducing that the toxicity of the extracts is low due to the low solubility of toluene but that the toxicity of toluene is high. On the basis of the experimental results, the amount of toluene diffused vs time in plane sheet systems was studied. A kinetic model has been developed considering two stages: In the first stage, the toluene diffuses into the system across the neoprene chains at a constant rate, not depending on the initial toluene concentration. This fact is explained by considering that there is a constant difference of the toluene concentration between the interface with the water and the inner part of the sample. In the second stage, the dispersion of the polymer with the corresponding amount of toluene takes place. The diffusion of toluene in the leaching process is compared and analyzed considering the diffusion of toluene in a desorption process in air so that the difference of toluene concentration between the interface and the interior can be estimated. A mathematical model is also proposed for considering the leaching process in other operating conditions.

Primary cutaneous large B-cell lymphoma: the relation between morphology, clinical presentation, immunohistochemical markers, and survival

The histogenesis, morphology, immunophenotype, and clinical behavior of cutaneous large B-cell lymphomas (CLBCL) are largely a matter of controversy. We performed an investigation to determine whether CLBCL have features that differentiate them from other large B-cell lymphomas and whether CLBCL is itself a heterogeneous group. To this end, we reviewed the main characteristics of a series of 32 cases of LBCL found in the skin. We reviewed the clinical findings and paraffin sections of the tumors from these 32 patients. The immunohistochemical study performed included p53, MIB1, Bcl2, Bcl6, and CD10 markers. We carried out statistical analysis of these data (univariate and multivariate), seeking an association between the features of the tumors and clinical outcome, as defined by failure-free survival time. Only one patient died as a consequence of the lymphoma. Nevertheless, the accumulated probability of survival without failure at 48 months was 0.46. The number, type, and localization of the lesions were not associated with variations in either survival or failure-free survival. The expression of p53 was negative in this group of CLBCL, whereas Bcl-2 expression or localization in the lower leg did not relate to any other significant feature. Histologic examination of the cases disclosed three different groups: Grade III follicular lymphomas (FLs), monomorphous large B-cell lymphomas (LBCL type I), and LBCL with an admixed component of small B-lymphocytes (LBCL type II). Grade III FL (11 cases) tended to be found in the head and neck and showed CD10 expression in a majority of cases. A higher probability of lymph node relapses was associated with cases located in the head and neck and with CD10+ tumors. Cutaneous large B-cell lymphomas are indolent tumors, but follow an insidious course. Our data support the interpretation that CLBCL is a heterogeneous condition; comprises some LBCL derived from CD10+ germinal center cells which manifests more frequently as tumors in the head and neck region, with an increased probability of relapse in lymph nodes [1] and has some distinctive morphologic features. The existence of a component of small B-cells within the other CLBCL could lend support to the theory that some of these tumors, more than arise de novo, may have originated in preexistent small B-cell lymphomas, but no firm evidence of this is provided in this study.

Polyphenol oxidase activity, color changes, and dehydration in table grape rachis during development and storage as affected by n-(2-chloro-4-pyridyl)-n-phenylurea

Flame Seedless grapes were sprayed with N-(2-chloro-4-pyridyl)-N-phenylurea (CPPU) at 0, 2.5, and 5.0 ppm to develop rachis resistant to browning and dehydration. Rachis polyphenol oxidase (PPO) activity was determined during cluster development. Cluster components were weighed at commercial (CM), and physiological maturity (PM). PPO activity, rachis color changes (L and a), and cluster weight loss were evaluated at 0 degrees C for 8, 16, 32, and 56 days. CPPU-treated rachis had a decrease of 36% in PPO activity and a week delay in peak activity. At PM, dry weight of CPPU-treated rachis increased by 3 g. Postharvest rachis PPO activity declined with CPPU application, and color changes followed the same pattern for CM and PM. After 32 days of storage, L and a in lateral branches were significantly superior in CPPU treatments. Weight losses below 2.1% were significantly lowest in CPPU-treated clusters for 16 days of storage regardless of cluster maturity.

Frequency and determinants of microalbuminuria in mild hypertension: a primary-care-based study

OBJECTIVE

To evaluate the frequency of microalbuminuria and its relationship with several risk factors and left ventricular mass in a population of mildly hypertensive subjects attended in a primary-care setting.

DESIGN

Cross-sectional study.

SETTING

Eight primary-care centres.

PATIENTS

Two hundred and twenty-three non-diabetic patients recently diagnosed with mild hypertension were included in the study. None of them had clinical evidence of target-organ damage or had received prior antihypertensive treatment.

INTERVENTIONS

Subjects included in the study underwent clinical interview, measurement of blood pressure (BP) on three visits, blood analysis, measurement of albumin by immunonephelometry in three overnight urine collections, 24 h BP monitoring and M-mode and Doppler echocardiography.

MAIN OUTCOME MEASURES

Tobacco habit, clinic BP, body mass index, serum lipids and uric acid, glycaemia, urinary albumin excretion (UAE), ambulatory BP and left ventricular mass index.

RESULTS

The frequency of microalbuminuria was 7.2%. Microalbuminuric patients were more likely to be men and to be characterized by higher ambulatory BP, body mass index and uric acid levels. Regression analysis demonstrated that male sex and 24 h systolic BP were determinants of UAE. Patients with white-coat hypertension showed lower UAE than did subjects with sustained hypertension. Although a certain relationship between UAE and left ventricular mass index was found, these variables were not significantly correlated.

CONCLUSIONS

A low proportion of mildly hypertensive patients attended in a primary care setting are microalbuminuric. In this population, UAE is an expression of BP values over 24 h and correlates with several risk factors.

Influence of cortisol status on leptin secretion

The discovery of the adipocyte-produced hormone leptin has changed the field of obesity research and our understanding of energy homeostasis. It is now accepted that leptin is the afferent loop informing the hypothalamus about the states of fat stores, with hypothalamic efferents regulating appetite and energy expenditure. I addition, leptin has a role as a metabolic adaptator in overweight and fasting states. New and previously unsuspected neuroendocrine roles have emerged for leptin. Leptin participates in the expression of CRH in the hypothalamus, interacts at the adrenal level with ACTH, and is regulated by glucocorticoids. Since leptin and cortisol show an inverse circadian rhythm, it has suggested that a regulatory feedback is present. However glucocorticoids appears to play a modulatory, but not essential roles in generating leptin diurnal rhythm. Glucocortiocids act directly on the adipose tissue and increase leptin synthesis and secretion in humans. Leptin levels are markedly increased in Cushing's syndrome patients and in other pseudo-Cushing's syndrome states. Glucocorticoids appears to act as a key modulator of body weight and food intake, promoting leptin secretion by adipocytes, limiting central leptin induced effects and favoring those of the NPY. Furthermore the modulatory role of glucocorticoids could be altered in obesity, but the precise mode of action remains to be established. The relevance of this finding merits further studies.

Role of a dipeptide insertion between codons 69 and 70 of HIV-1 reverse transcriptase in the mechanism of AZT resistance

The 3'-azido-3'-deoxythymidine (AZT)-resistant pheno type of a heavily mutated human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) carrying a dipeptide (Ser-Ser) insertion between codons 69 and 70 as well as other mutations related to resistance to RT inhibitors has been studied. Recombinant virus carrying this variant RT (termed SS RT) showed reduced susceptibility to all nucleoside RT inhibitors in clinical use, particularly to AZT. In the presence of ATP, recombinant SS RT had an increased ability to remove the 3'-terminal nucleotide from AZT- terminated primers and extend the unblocked primer, compared with wild-type HIV-1 RT (BH10 isolate). Insertion of two serines in the sequence context of BH10 RT did not affect the ATP-dependent phosphorolytic activity of the enzyme, and had no influence in resistance to RT inhibitors. However, SS RT mutants lacking the dipeptide insertion or bearing a four-serine insertion showed reduced ATP-dependent phosphorolytic activity that correlated with increased AZT sensitivity, as determined using a recombinant virus assay. Therefore, the insertion appears to be critical to enhance AZT resistance in the sequence context of multidrug-resistant HIV-1 RT.

[Premature labor with intact membranes: microbiology of the amniotic fluid and lower genital tract and its relation with maternal and neonatal outcome]

BACKGROUND

The prevalence of idiopathic spontaneous premature labor or without an evident clinical cause, has not been reduced with tocolytic treatments, suggesting that premature labor has multiple causes and infections play a not well-defined role.

AIM

To perform microbiological studies of the amniotic fluid and of the lower genital tract in women with idiopathic premature labor and intact membranes, relating these findings with maternal and neonatal outcomes.

PATIENTS AND METHODS

Women with pregnancies between 24 and 34 weeks, with premature labor and without an evident clinical cause were enrolled. Amniotic fluid and genital tract samples were obtained for traditional microbiological cultures. This information was related with delivery events and neonatal outcome.

RESULTS

Sixty-three patients were included. The overall frequency of microbial invasion of amniotic cavity was 23.8% and of cervical or vaginal infection was 63.5% (in 39.7% there was only cervical or vaginal infection without involvement of the amniotic sac). Absence of infection was documented in 36.5% of women. Compared to patients without infection, women with microbial invasion of amniotic cavity had a higher rate of prematurity (73.3% p < 0.05), a higher rate of prematurity of less than 34 weeks (60% p < 0.01), a higher frequency of preterm rupture of membranes (40% p < 0.001), a shorter admission-to-delivery interval (median 3.0 days p < 0.01) and lower gestational age at delivery (median 33 weeks p < 0.01). Clinical chorioamnionitis and endometritis (20% p < 0.01) was observed only in patients with amniotic cavity infections. Severe asphyxia (26.7% p < 0.05) and neonatal admission to Intensive Care Units (46.7% p < 0.05) were more frequent and neonatal weight was less in the offspring of women with microbial invasion of amniotic cavity (2020 g median p < 0.01).

CONCLUSIONS

In preterm labor with intact membranes, intraamniotic infection is the most frequent cause of prematurity and is associated with a higher prevalence of maternal and neonatal problems.

Adaptation of the exocrine pancreas to dietary fats

This article reviews studies on the adaptation of the exocrine pancreas to dietary fat. We include all the latest information about the mechanisms that underlie the adaptation of the secretory mechanism of the exocrine pancreas to the amount and the type of dietary fat. We review the kinetics of pancreatic adaptation and the mediators of the adaptive response of the pancreas including cellular and molecular mechanisms (modulation of intracellular messengers and gene expression of the different enzymes and secretagogues involved in the adaptation process). At the same time we include our results in this field in dogs and humans.

Effect of neuropeptide Y on the sympathetic contraction of the rabbit central ear artery during cooling

In order to analyse the effect of neuropeptide Y (NPY) on the cutaneous vascular response to sympathetic nerve stimulation during cooling, the isometric response of isolated 2-mm segments of the rabbit central ear (cutaneous) artery was recorded at 37 degrees C and during cooling (30 degrees C). Electrical field stimulation (4-16 Hz) at 37 degrees C produced a frequency-dependent contraction, which was reduced during cooling (45% for 16 Hz) and potentiated by NPY (10(-8), 3x10(-8) and 10(-7) M), this potentiation being greater at 30 degrees C than at 37 degrees C. The NPY-induced potentiation of the contraction elicited by electrical field stimulation (8 Hz) was abolished by an antagonist of Y1 subtype NPY receptors, BIBP3226 (10(-6) M), at 37 degrees C and 30 degrees C, reduced by phentolamine (10(-6) M) at 30 degrees C but not at 37 degrees C, was not modified by the purinoceptor antagonist PPADS (3x10(-5) M) and was reduced by application of both phentolamine and PPADS at both temperatures. Both NiCl2 (10(-3) M) and verapamil (10(-5) M) abolished the potentiating effect of NPY at 37 degrees C and reduced it at 30 degrees C. Neither application of an inhibitor of nitric oxide synthesis, L-Nomega-nitro-arginine (L-NOARG, 10(-4) M), nor endothelium removal modified the potentiating effect of NPY at 37 degrees C or 30 degrees C. NPY (10(-8), 3x10(-8) and 10(-7) M) potentiated in a concentration-dependent way the arterial contraction in response to exogenous noradrenaline (10(-8)-10(-4) M) at 30 degrees C but not at 37 degrees C, and it increased the response to ATP (10(-4)-10(-2) M) at both temperatures. Therefore, in cutaneous (ear) arteries: (1) NPY potentiates the sympathetic response at 37 degrees C and at 30 degrees C, (2) this potentiating effect of NPY was more marked at 30 degrees C than at 37 degrees C, probably because of greater potentiation of the alpha-adrenoceptor response during cooling, and (3) the potentiating effect of NPY at both temperatures is mediated by NPY receptors of the Y1 subtype, is dependent of Ca2+ channels and is independent of the release of endothelial nitric oxide.

[Prospective, randomized, comparative study of the efficacy, safety and cost of cefuroxime versus cephradine in acute pyelonephritis during pregnancy]

BACKGROUND

Second generation cephalosporins (CFPs) are more active in the treatment of acute pyelonephritis during pregnancy but their cost is considerably higher than their predecessors. Cefuroxime, a second generation CFP with oral and parenteral presentations, might offer significant advantages and become a first choice antimicrobial in this setting.

AIM

To compare the efficacy, safety and cost of cefuroxime and cephradine in the treatment of acute pyelonephritis in pregnancy.

PATIENTS AND METHODS

Hospitalized women with 12 to 34 weeks of pregnancy, with clinical and bacteriological diagnosis of acute pyelonephritis, were randomly assigned to receive cefuroxime (Curocef(r), Glaxo Wellcome) 750 mg t.i.d, i.v. or cephradine 1 g q.i.d., i.v. If the isolated organism was resistant to the assigned drug the patient was excluded. Once patients were afebrile, they were switched to an oral form of the same antimicrobial. They were discharged according to the clinical status and treated for a total of 14 days. laboratory tests, including urine culture were requested during controls and at the end of follow-up at 28 days.

RESULTS

One hundred and one patients were randomized: 49 to receive cephradine and 52 to receive cefuroxime. Patients in the cefuroxime group hed fewer febrile days (mean 1.7 vs 2.2, p < 0.05), faster clinical recovery (mean 2.7 vs 3.1 days, p < 0.05), a higher rate of bacteriological cure at 28 days (78.8% and 59.2%, p < 0.05) and lower rate of failure (21.2% vs 40.8% p < 0.05). The rate of resistance of isolated uropathogens was 14% to cephradine and 1% to cefuroxime.

CONCLUSIONS

Cefuroxime can be considered as a first choice option in the treatment of acute pyelonephritis during pregnancy due to its tolerance, microbiological activity and efficacy.

Suprasellar chordoid glioma

Brat et al. (J Neuropathol Exp Neurol 57:288-290, 1998) reported eight cases of a new clinico-pathological entity, which occurs mainly in the third ventricle of middle-aged females, which they described as chordoid glioma of the third ventricle. We report a new case of a 41-year-old woman with a suprasellar chordoid glioma with histological, immunohistochemical and ultrastructural studies. We discuss the differential diagnosis between chordoma, chordoid meningioma, germinoma and pituitary adenoma. Histologically, the tumour showed cords and lobules of isomorphic epithelioid cells in a vacuolated matrix with prominent multifocal lymphoplasmacytic infiltrates in which some histiocytes and isolated Touton-type giant cells were seen; cells were immunoreactive for glial fibrillary acidic protein but negative for epithelial membrane antigen. Ultrastructural examination revealed abundant intermediate filament but no desmosomes, microvilli nor cilia were seen.

Double versus single renal allografts from aged donors

BACKGROUND

The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient.

MATERIAL AND METHODS

In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation.

RESULTS

Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group II (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P<0.01) and III (50%, P<0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0.05).

CONCLUSIONS

Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.

Tumor necrosis factor-alpha increases the steady-state reduction of cytochrome b of the mitochondrial respiratory chain in metabolically inhibited L929 cells

The mechanism of tumor necrosis factor alpha (TNFalpha)-induced cytotoxicity in metabolically inhibited cells is unclear, although some studies have suggested that mitochondrial dysfunction and generation of reactive oxygen species may be involved. Here we studied the effect of TNFalpha on the redox state of mitochondrial cytochromes and its involvement in the generation of reactive oxygen species in metabolically inhibited L929 cells. Treatment with TNFalpha and cycloheximide (TNFalpha/CHX) induced mitochondrial cytochrome c release, increased the steady-state reduction of cytochrome b, and decreased the steady-state reduction of cytochromes cc(1) and aa(3). TNFalpha/CHX treatment also induced lipid peroxidation, intracellular generation of reactive oxygen species, and cell death. Furthermore, as the cells died mitochondrial morphology changed from an orthodox to a hyperdense and condensed and finally to a swollen conformation. Antimycin A, a mitochondrial respiratory chain complex III inhibitor that binds to cytochrome b, blocked the formation of reactive oxygen species, suggesting that the free radicals are generated at the level of cytochrome b. Moreover, antimycin A, when added after 3 h of TNFalpha/CHX treatment, arrested the further release of cytochrome c and the cytotoxic response. We propose that the reduced cytochrome b promotes the formation of reactive oxygen species, lipid peroxidation of the cell membrane, and cell death.

Genetic evolution of GB virus C/hepatitis G virus (GBV-C/HGV) under interferon pressure

The epidemiology and clinical features of chronic GBV-C/HGV infection have largely been explored, but there is little information about the mechanisms enabling GBV-C/HGV to cause persistent infection. Since analysis of the genomic variation of GBV-C/HGV under interferon pressure might provide some insight into this issue, we analyzed the nucleotide sequence variation of the 5'NC and NS3 regions in GBV-C/HGV isolates obtained sequentially from seven patients co-infected with HCV and treated with interferon. A reduction of GBV-C/HGV-RNA serum level below the detection limit of the RT-PCR assay was observed during treatment in all patients, but upon interferon withdrawal, viral RNA remained undetectable in only two patients. Among the five patients who did not clear GBV-C/HGV-RNA, viral strains emerging after treatment were identical to those present at baseline in three cases. In a further case, in whom GBV-C/HGV-RNA re-emerged during therapy (breakthrough episode), several mutations appeared in relapse samples. In the remaining patient, with a mixed infection before therapy, only one of the two GBV-C/HGV strains present at baseline was detected upon treatment withdrawal. These data raise the possibility that positive selection may act over GBV-C/HGV genome during interferon therapy, and contribute to persistence of infection with this virus.