A polisher for patch pipets

The design and construction of a novel apparatus to fire polish patch-clamp recording pipets is described. The device positions the polishing filament in the field of view of the high-power polishing objective and uses the mechanical stage of the microscope to hold the electrode, climinating the need for a micromanipulator to hold either the filament or electrode.     

Mapping study of noradrenergic stimulation of vasopressin release

The precise role of hypothalamic norepinephrine (NE) in the control of vasopressin (AVP) release has remained unclear, due to reports of both inhibitory and excitatory effects of NE and only a few studies with direct hypothalamic manipulations. The present study utilized a chronically implanted swivel brain cannula to investigate, in undisturbed and freely behaving rats, the impact of acute hypothalamic infusions of monoamines on circulating AVP levels. The first study examined and compared the responsiveness of six hypothalamic sites to NE infusion through the swivel cannula. Results indicated that the excitatory effect of central noradrenergic stimulation on serum AVP is highly site specific, localized to the paraventricular (PVN) and supraoptic (SON) nuclei. These two nuclei appeared to be equally responsive to NE infusion, yielding a threefold rise in serum AVP over baseline levels. In contrast, NE in the dorsomedial nucleus produced a significantly smaller increase in AVP, and no response was observed in the ventromedial nucleus, posterior hypothalamus, or perifornical lateral hypothalamus. Further tests conducted in the PVN showed this nucleus to respond in a dose-dependent manner to NE infusion. In contrast, under similar test conditions, dopamine caused only a small increase in AVP at a relatively high dose, while a PVN injection of serotonin produced no response. These results support the existence of an excitatory noradrenergic system controlling AVP release and specifically demonstrate that this function of NE is localized to the PVN and SON, in contrast to other hypothalamic areas, and is mimicked to some extent by dopamine but not by serotonin.     

混合物体系的纯组分红外光谱辨析

用迭代目标转换因子分析法,对混合体系的红外光谱的纯组分光谱辨析进行了研究。三组分及二组分的氨基酸混合体系的纯组分红外光谱辨析结果表明,该法可获满意效果。     

The effect of convergence on the vestibulo-ocular reflex and implications for perceived movement

The apparent motion of a fixated stimulus during head translation in the dark was found to depend on the magnitude of the vestibulo-ocular reflex (VOR). Absolute convergence level determines VOR magnitude and thereby influences apparent motion during head movement by determining the magnitude and direction of the pursuit effort required to maintain gaze stability. The results are discussed in terms of the biological utility of the coupling between convergence and the VOR in maintaining image stability, and the role of the pursuit eye movement system in illusory movement.     

Improvement in grasp skill in children with hemiplegia with the MacKinnon splint

This study evaluated the use of the MacKinnon splint upon grasp skills in three children, ages 2 1/2 to 7 1/2, with spastic hemiplegia. The MacKinnon splint was sequentially introduced in a multiple baseline design across subjects. The results indicated improvement in each child's grasp of eight different, randomly presented objects, after a MacKinnon splint was provided for daily wear.     

Suppression of neuropeptide Y-elicited eating by adrenalectomy or hypophysectomy: reversal with corticosterone

Neuropeptide Y (NPY) injected into the paraventricular hypothalamus (PVN) stimulates a robust eating response in the satiated rat. To examine whether the NPY-feeding system interacts with the pituitary-adrenal axis, the eating response to PVN injections of NPY (78 pmol) was tested in adult male rats before and after sham surgery, adrenalectomy (ADX), hypophysectomy (HYPX), and/or corticosterone (CORT) replacement therapy. In unoperated or sham groups, NPY elicited 5.7-8.8 g of food intake in 1 h as compared to 0.4-1.1 g for vehicle-injected animals. In ADX groups, the NPY-elicited response was reduced by 60-71%, to between 2.4 and 2.8 g. Likewise, the average response of the HYPX group was reduced by 69%, to 1.7 g. Corticosterone replacement, via subcutaneous implant of a 100 mg CORT pellet, normalized the NPY-induced feeding response in both the ADX and HYPX groups. These findings suggest that the hypothalamic NPY-feeding system is largely dependent upon circulating CORT and that no other adrenal or pituitary hormone is essential.     

Chronic daily headache- one disease or two? Diagnostic role of serum ionized magnesium

The entity of chronic daily headache (CDH) is well documented, but is not included in the current classification. We divided patients with CDH into groups with and without migrainous features. This division resulted in clearly distinguishable syndromes of daily migrainous headaches (DMH) and daily tension-type headaches (DTH). Family history of headaches was more common in patients with DMH. Patients in both groups had a high incidence of caffeine or drug overuse. The clinical division into DMH and DTH was supported by our finding of a higher incidence of disturbed magnesium (Mg) metabolism in patients with DMH. Of 26 patients with DMH, 8 (30.8%) had low serum ionized, but not total, Mg levels, and 16 (61.5%) had high ionized calcium/magnesium ratios. The corresponding numbers for the 22 patients with DTH were 1 (4.5%) and 8 (30.4%). These new laboratory measurements offer possible biological markers for the diagnosis of different headache syndromes.     

Chronic myeloid leukaemia in South African blacks.

A study on 25 South African Black patients with chronic myelogenous leukaemia (CML), who were followed for 3 1/2 years, is reported. The Ph chromosome was found in 19 of 20 patients studied. Males predominated in a ratio of 2,5:1. Several unusual clinical features were encountered: significant lymphadenopathy, congestive cardiac failure and skin lesions. Patients with lymphadenopathy responded to busulphan therapy no differently from patients without lymphadenopathy. Nine patients had congestive cardiac failure, and in 7 of these a cause could not be found. Three untreated patients became pregnant, indicating that CML per se does not cause infertility. The haematological measurements were similar to those of previous reports; however, the marked splenomegaly suggests that South African Black patients present themselves for treatment rather late in the disease. The median survival time of 34 months is similar to that of previous reports of larger series from other parts of the world.