Pattern electroretinogram and visual evoked potential amplitudes are influenced by different stimulus field sizes and scotomata

The pattern electroretinogram and the visual evoked potential were recorded simultaneously with various stimulus fields and artificial scotomata of increasing sizes. In contrast to an earlier study, a smaller check size (20) and two stimulus field sizes (20° × 20° and 10° × 10°) for the scotomata were used. With a concentric decreasing stimulus field, a reduction of both the pattern electroretinogram and visual evoked potential was found. Both showed a simultaneous reduction of amplitudes, but, compared with the amplitude in the full field, the reduction was more extensive for the pattern electroretinogram at each test field size. This implies a greater contribution to the pattern electroretinogram from more eccentric retinal parts. An artificial central scotoma of increasing size in the 20° × 20° field had less influence on the pattern electroretinogram than on the visual evoked potential. The percentage amplitude loss of the visual evoked potential was more pronounced. The visual evoked potential was eventually abolished by a scotoma size from 10° × 10° upward, while the pattern electroretinogram was still registrable. When scotomata of similar size were introduced in a smaller (10° × 10°) field, percentage pattern electroretinogram and visual evoked potential amplitude losses were less separated than in a larger (20° × 20°) test field.     

Sympathoinhibition by rilmenidine in conscious rabbits: involvement of α2-adrenoceptors

Summary Cardiovascular and sympathetic nervous system effects of the mixed ₂-adrenoceptor and imidazoline receptor agonist rilmenidine were studied in conscious rabbits chronically instrumented for the recording of the firing rate of renal sympathetic fibers. Separate experiments were carried out on pithed rabbits with electrically stimulated (2 Hz) sympathetic outflow. Drugs were administered intravenously in a cumulative manner.In conscious rabbits, rilmenidine 0.1, 0.3 and 1.0 mg kg^–1 dose-dependently lowered blood pressure, renal sympathetic nerve activity, heart rate and the plasma concentration of noradrenaline and adrenaline. The effect on blood pressure and plasma catecholamines was maximal after 0.3 mg kg^–1 whereas heart rate and renal sympathetic nerve activity decreased further after rilmenidine 1.0 mg kg^–1. Yohimbine 0.1 and 0.5 mg kg^–1, when injected subsequently, attenuated and at the higher dose abolished all effects of rilmenidine. The effects of rilmenidine were also antagonized by the ₂-adrenoceptor antagonist 2-(2,3-dihydro-2-methoxy-1,4-benzodioxin-2-yl)-4,5-dihydro-1H-imidazole HCl (RX821002; 0.1 and 0.5 mg kg^–1). Yohimbine 0.1 and 0.5 mg kg^–1 did not attenuate or attenuated only slightly the decrease of heart rate and renal sympathetic nerve activity produced by infusion of vasopressin. In pithed rabbits with electrically-stimulated sympathetic outflow, yohimbine 0.1 submaximally and yohimbine 0.5 mg kg^–1 maximally increased the plasma noradrenaline concentration.The experiments show by direct measurement of sympathetic nerve firing and plasma catecholamines that rilmenidine causes sympathoinhibition in conscious rabbits, presumably through central sites of action. The antagonism by yohimbine, at doses which are selective for ₂-adrenoceptors (vs. imidazoline receptors), demonstrates the involvement of ₂-adrenoceptors in the sympatho-inhibition.Correspondence to: B. Szabo at the above address     

Inhibition of uptake1 by (+)-oxaprotiline reveals a differential central regulation of noradrenaline and adrenaline release

Summary Inhibition of uptake, in the central nervous system leads to a decrease of sympathetic outflow to many tissues; central a2-adrenoceptors are involved in this decrease. The aim of the present study was to compare the effects of the selective uptake, inhibitor (+)-oxaprotiline on the plasma kinetics of noradrenaline and adrenaline in anaesthetized and in conscious rabbits. [³H]Noradrenaline and [^3H]adrenaline were infused iv. The arterial plasma concentrations of endogenous and radiolabelled noradrenaline and adrenaline were measured, and the clearance from and spillover into the plasma of noradrenaline and adrenaline were calculated.Results obtained in conscious and anaesthetized rabbits were similar. (+)-Oxaprotiline 0.2, 0.6 and 1.8 mg kg^–1 iv. dose-dependently reduced the clearance of [³H]noradrenaline from the plasma. The clearance of [³H]adrenaline was reduced less. The spillover of endogenous noradrenaline was decreased by up to 35%. In contrast, the spillover of adrenaline tended to be enhanced. Prazosin 0.1 and 1 mg kg^–1 was injected iv. in a second part of each experiment. It lowered the blood pressure and caused a marked increase in noradrenaline spillover but no increase or even a decrease in adrenaline spillover.The results are compatible with the following hypothesis. The sympathetic outflow from the central nervous system is subject to a twofold a-adrenoceptor-mediated modulation: -adrenoceptor-mediated inhibition and ₁-adrenoceptor-mediated excitation. In the control of the sympathetic outflow to many extra-adrenal tissues, the ₂-adrenergic inhibition prevails. Uptake₁ inhibitors depress sympathetic outflow to such tissues by enhancing the ₂-adrenergic inhibition. In the regulation of the sympathetic outflow to the adrenal medulla, in contrast, ₂-adrenergic inhibition and ₁-adrenergic excitation have a similar impact. Uptake, inhibitors, hence, cause little change in adrenaline release: the two opposing influences cancel out. Prazosin produces an increase in noradrenaline but not adrenaline release because the loss of the central ₁ sympathoexcitation attenuates at best slightly the baroreflex to most extra-adrenal tissues but dampens markedly the baroreflex to the adrenal medulla. Correspondence to B. Szabo at the above address     

The distally based subcutaneous tarsometatarsal flap

Injuries to the distal part of the foot, or even the toes, can still provide reconstructive problems. It is not always wise to amputate the damaged, distal part of the foot. Some surgeons have stated that reconstruction of the distal foot is not necessary, but it is our opinion that it has a similar priority to reconstruction of the hand. While large defects are mostly reconstructed by free flaps, minor defects should also be considered for reconstruction. As in a previous paper, Small toe muscles for defect coverage [12], we are presenting a new way to reconstruct damaged tissue distal to the tarsometatarsal region.Correspondence to: G. Wechselberger     

Total parenteral nutrition directly impairs cytokine production after bacterial challenge

BACKGROUND/PURPOSE: Previous studies have shown that total parenteral nutrition (TPN) influences host immunity, but the mechanism is unclear. This study explored the effect of TPN solution on neutrophil phagocytosis and whole-blood cytokine production in response to coagulase-negative staphylococci in vitro challenge. METHODS: Blood samples were taken from five enterally fed infants (age <6 months) and six healthy adults. Samples were incubated for 45 minutes with four isovolemic solutions: (A) control (saline), (B) TPN (0.1 microL/mL of blood), (C) TPN (1 microL/mL), (D) TPN (10 microL/mL). Solution C (1 microL/mL) corresponded to TPN-blood ratio used in clinical practice. After incubation, blood was challenged with coagulase-negative staphylococci. Neutrophil phagocytosis was measured by flow cytometry after 40 minutes of bacterial challenge, and tumour necrosis factor alpha (TNF-alpha) was measured by enzyme-linked immunosorbent assay (ELISA) after 2 hours of bacterial challenge. RESULTS: In infant blood, TNF-alpha production after coagulase-negative staphylococci challenge was impaired after the addition of a "physiological" dose of TPN solution (1 microL/mL of blood) as well as "supranormal" doses (10 microL/mL of blood). In adult blood, a similar effect was observed only after the addition of a supranormal dose of TPN. In both the infant and adult blood, there was no direct effect of TPN solution on neutrophil phagocytosis. CONCLUSIONS: These results suggest that infants are more susceptible than adults to TPN-related depression of cytokine production. The level of proinflammatory cytokines may be important in the host defence against bacterial infection.     

Development of Hungarian heart surgery, its results and current state in the light of the 40-year activity of the "Városmajor Clinic". Review of 40 years of surgery in Hungary, analysis of mortality data]

Forty years have passed since the first heart surgical department was founded in Hungary. In the University Hospital (present name: Cardiovascular Surgical Clinic of Semmelweis Medical University of Budapest) the Hungarian "pioneers" had produced internationally respected results in the mid-fiftieth with the operation of closed mitral commissurotomy. However the technique of cardiopulmonary bypass was first introduced into the clinical practice quite early, it has not become a routine everyday procedure until the late seventies. Over the last 15 years period the number of open heart surgical cases has increased permanently, and the operative mortality decreased at the same time. The analysis of 4743 cases performed between 1976 and 1990 showed improving results both in the field of valve replacement and coronary artery surgery and the recent operative mortality figures (3-5% in different groups) are comparable to other European centers.     

Selective termination of the development of the defective fetus in discordant twin pregnancies

Selective termination of the affected fetus in twin pregnancies was performed in the second trimester of seven pregnancies. The malformations included anencephaly/exencephaly (2 cases), hydrocephalus (1 case), thoracoabdominopagus of "B" and "C" cotwins (1 case), urethral obstruction sequence (1 case) and hygroma colli (2 cases). Intrauterine intervention on the affected fetus was done by transabdominal intracardial injection of 20% NaCl solution in the 15--24 weeks of gestation. All cases had dichorionic placentation. Unaffected co-twin infants were delivered at term with normal weight in 4 cases. In 2 cases the affected fetus was found in the lower gestational sac and both pregnancies, as well as the triplet pregnancy were lost 1--6 weeks and 3 weeks after the intervention, respectively. In the other cases, neither the mother, nor the survived fetus showed any complications. We believe that using hypertonic saline is lethal for the affected fetus but carries little or no risk either the other fetus or the mother, even if small amounts of the solution might inadvertently enter their circulation.     

Effect of agomelatine in the chronic mild stress model of depression in the rat.

Chronic mild stress (CMS), a well-validated model of depression, was used to study the effects of the melatonin agonist and selective 5-HT(2C) antagonist agomelatine (S 20098) in comparison with melatonin, imipramine, and fluoxetine. All drugs were administered either 2 h before (evening treatment) or 2 h after (morning treatment) the dark phase of the 12-h light/dark cycle. Chronic (5 weeks) evening treatment with agomelatine or melatonin (both at 10 and 50 mg/kg i.p.) dose-dependently reversed the CMS-induced reduction in sucrose consumption. The magnitude and time course of the action of both drugs was comparable to that of imipramine and fluoxetine (both at 10 mg/kg i.p.); however, melatonin was less active than agomelatine at this dose. The effect of evening administration of agomelatine and melatonin was completely inhibited by an acute injection of the MT(1)/MT(2) antagonist, S 22153 (20 mg/kg i.p.), while the antagonist had no effect in animals receiving fluoxetine or imipramine. When the drugs were administered in the morning, agomelatine caused effects similar to those observed after evening treatment (with onset of action faster than imipramine) but melatonin was ineffective. Moreover, melatonin antagonist, S 22153, did not modify the intakes in stressed animals receiving morning administration of agomelatine and in any other control and stressed groups tested in this study. These data demonstrate antidepressant-like activity of agomelatine in the rat CMS model of depression, which was independent of the time of drug administration. The efficacy of agomelatine is comparable to that of imipramine and fluoxetine, but greater than that of melatonin, which had no antidepressant-like activity after morning administration. While the evening efficacy of agomelatine can be related to its melatonin receptors agonistic properties, its morning activity, which was not inhibited by a melatonin antagonist, indicates that these receptors are certainly required, but not sufficient to sustain the agomelatine efficacy. It is therefore suggested that the antidepressant-like activity of agomelatine depends on some combination of its melatonin agonist and 5-HT(2C) antagonist properties.     

A descriptive analysis of STD prevalence among urban pregnant African-American teens: data from a pilot study.

OBJECTIVE: To assess the prevalence of sexually transmitted diseases (STDs) among a sample of African-American adolescent females at the time of their first prenatal visit and to assess key characteristics of those testing positive for sexually transmitted diseases. The study also determined differences in these characteristics between adolescents who were and those who were not diagnosed with an STD. METHODS: One-hundred-and-seventy pregnant African-American adolescents (aged 14-20 years; mean = 17.5 years) receiving their first prenatal visit were recruited at a prenatal clinic located in a large urban hospital. Biological assessment included nucleic acid amplification testing for gonococcal, chlamydial, and trichomonal infections. Rapid plasma reagin testing assessed infection with syphilis. A self-administered survey and in-depth face-to-face interview were used to collect detailed information assessing adolescents' sociodemographic characteristics, psychosocial indices, and their recent sexual risk behaviors. Data were analyzed using Student's t-tests and contingency table analyses, respectively, for continuous and categorical variables. RESULTS: Overall, 23.5% tested positive for one of the four STDs. Thirteen percent were infected with Chlamydia trachomatis, 1.2% with Neisseria gonorrhoeae, 8.9% with Trichomonas vaginalis, and 1.2% with Treponema pallidum. More than one-half reported recent (past 6 months) treatment for an STD, 30% of these tested positive for at least one of the four STDs assessed. Adolescents testing positive for STDs held favorable attitudes toward condom use, but levels of sexual risk were generally high. There were no sociodemographic, psychosocial, and sexual-risk differences between those testing positive and negative. CONCLUSION: Findings support STD screening efforts targeting pregnant adolescents. Providing clinic-based counseling and prevention education programs to pregnant adolescents regardless of apparent risk factors may also be warranted.     

依那西普对银屑病患者疲劳和抑郁症状的临床疗效：一项双盲、随机、安慰剂对照、Ⅲ期试验

背景：银屑病对患者心理和情绪影响很大。依那西普治疗银屑病患者临床症状有效，作者评估了该药对银屑病相关疲劳和抑郁症状的疗效。方法：618例中至重度银屑病患者接受安慰剂或依那西普50mg（2次／周）双盲治疗。主要疗效终点：治疗12周时，银屑病面积和严重度指数评分较基线改善达75％（PASI 75）或更高水平；次要和其他疗效终点：慢性病治疗疲劳功能评估（FACIT-F）分级、Hamilton抑郁量表（Ham-D）分级、Beck抑郁列表（BDI）及不良事件。根据分组治疗进行疗效分析。基于实际接受治疗的情况对安全性资料进行分析和总结。