Analysis of antigen-stimulated B cell migration into germinal centers during the early stage of a T-dependent immune response

The quasimonoclonal (QM) mouse provides a model to analyze B cell selection because major B cell antigen receptors (BCR) are composed of the knockin V(H)DJ(H) 17.2.25 (V(H)T) encoded H chain and the lambda1 or lambda2 L chain, thereby being specific for (4-hydoxy-3-nitrophenyl)acetyl (NP). We have reported that during a T-dependent antibody (Ab) response for a low-affinity NP analog p-nitrophenylacetyl (pNP), although V(H)T/lambda1 and V(H)T/lambda2 IgM were equally produced, V(H)T/lambda2 IgG almost exclusively underwent affinity maturation toward pNP. The initial affinity of V(H)T/lambda2 B cells for pNP was approximately 50-100-fold higher than that of V(H)T/lambda1 B cells, suggesting a role of BCR affinity in recruiting B cells to affinity maturation processes. Here, we investigated whether the intensity of BCR signals could contribute to the selection of V(H)T/lambda2 B cells for affinity maturation. V(H)T/lambda2 B cells were more responsive to pNP than V(H)T/lambda1 B cells in vitro. When CFSE-labeled QM B cells were transferred into the wild type mice where T cells had been primed with chicken gamma-globulin (CGG), QM B cells challenged by pNP-conjugated CGG could be observed to get activated and migrate to GCs in the early phase of the T-dependent response to pNP-CGG. Adoptive transfer of sorted populations revealed that the V(H)T/lambda2 B cell population was more potent in migration into GCs than the V(H)T/lambda1 counterpart. Thus, it is suggested that the higher BCR affinity of V(H)T/lambda2 B cells may be an initial cue for their recruitment to GCs during a T-dependent Ab response.     

Field evaluation of an insect growth regulator, pyriproxyfen, against Anopheles punctulatus on north Guadalcanal, Solomon Islands.

Five pools containing immature stages of Anopheles punctulatus were treated with pyriproxyfen at 4 different dosages. Inhibition of adult emergence was observed in pupae collected from the test pools and/or those obtained by rearing of the 4th instar larvae. Adult emergence was inhibited completely for 2 months at a dosage of 0.1 ppm, for one month at 0.05 ppm and 0.01 ppm, and for 20 days at 0.02 ppm. Death of test insects were observed at the pupal stage and at adult emergence. The mortality rate at adult emergence increased with the duration of larval rearing and with the elapse of time after application.     

Valacyclovir neurotoxicity: clinical experience and review of the literature

Valacyclovir (VACV) is used increasingly to treat herpes zoster, although neuropsychiatric symptoms [VACV neurotoxicity (VAN) or acyclovir neurotoxicity], may accompany use of this drug. To promote awareness of this rare condition, we describe here two clinical cases of VAN we previously reported and review 20 cases from the literature. In all cases, chronic or acute renal failure preceded VAN. The symptoms of VAN varied, but disturbances of consciousness and hallucination occurred most commonly. When acute renal failure was due to the drug, recovery from both the disturbance of consciousness and renal failure followed within several days after discontinuation of VACV. Early recognition and diagnosis will ensure effective treatment of VAN.     

Episodic Psychotic States in Temporal Lobe Epilepsy: An Investigation on Their Physiopathogenesis

Abstract. The discussion here is about the direct relationship of epileptic seizures to episodic psychotic states. The episodic psychotic states were divided into three groups: interictal, ictal and postictal. In each group, one representative case was described and the neurophysiological pathogenesis discussed according to a recent research, mainly depth-electrode findings. It is believed that: 1) interictal psychotic state—limbic paroxysmal discharges play an important role in its pathogenesis, according to the theory of Geschwindt and others; 2) ictal psychotic state—repetitive auras develop to the psychotic state, and aura continua itself can be described as a psychotic state; and 3) postictal psychotic state—the increased limbic discharges might be responsible for the psychotic state. The common neurophysiological cause in all the three groups is due to the increased epileptic discharges in the limbic system. It is concluded that the episodic psychotic states in temporal lobe epilepsies are possibly of an epileptic nature in themselves.     

结扎膀胱下动脉改良Madigan前列腺切除术在临床的应用

为了探讨预防Madigan前列腺切除术中出血的方法，自1994年2月至1997年2月，在Madigan前列腺切除术中结扎膀胱下动脉35例，未结扎膀胱下动脉30例，术后57例随访3～36个月，结果显示结扎组术中出血明显减少，并认为改良术式具有不损伤尿道、保留性功能、简单易行的优点。对前列腺血管神经外科解剖及术中方法进行了讨论。     

Diagnosis of misery perfusion using noninvasive 15O-gas PET.

To avoid arterial blood sampling and complicated analyses in 15O-gas PET studies, we evaluated a noninvasive technique using the count-based method for measuring asymmetric increases in oxygen extraction fraction (OEF) in cerebrovascular disease. METHODS: Eighteen patients (mean age +/- SD, 61 +/- 16 y) with atherothrombotic large-cerebral-artery disease were studied for the measurement of hemodynamic parameters using the 15O-gas steady-state method with inhalation of 15O2, C15O2, and C15O. All patients also underwent H2(15)O PET with the bolus injection method. Count-based ratio images of 15O2/C15O2 and (15)O2/H2(15)O were calculated, and asymmetry indices (AIs) were obtained (cbOEF(SS)-AI and cbOEF(BO)-AI, respectively) using regions of interest drawn bilaterally on the cerebral cortices. These AIs were compared with the AIs of absolute OEF (qOEF-AI) and with those after cerebral blood volume (CBV) correction. A contribution factor for this correction was defined as a variable alpha, and the effect of the correction was evaluated. RESULTS: cbOEF(SS)-AI underestimated qOEF-AI significantly, especially with a greater AI (P < 0.05). cbOEF(BO)-AI linearly correlated well with qOEF-AI. CBV correction improved the slopes of regression lines between qOEF-AI and cbOEF(SS)-AI, and the optimal alpha was defined as 0.5. On the other hand, cbOEF(BO)-AI fairly estimated qOEF-AI without CBV correction. Correlation between qOEF-AI and cbOEF(BO)-AI was adversely affected, and the mean bias was increased, with a greater alpha. CONCLUSION: cbOEF(BO)-AI can fairly estimate the AI of OEF without CBV correction, whereas cbOEF(SS)-AI might require CBV correction for better estimation. The examination time and stress to patients would be reduced with the count-based method because it is noninvasive.