Melatonin reduces nitric oxide synthase activity in rat hypothalamus

Abstract: In this report, rat hypothalamic nitric oxide synthase (NOS) activity is shown to be partially inhibited by physiological concentrations of the pineal hormone melatonin. In vitro studies demonstrate that 1 nM melatonin, which approximates the physiological concentration of the hormone at night, significantly inhibited NOS activity. In vivo studies show that administering melatonin or collecting the hypothalamus from animals at night, when endogenous melatonin levels are elevated, results in a significant decrease of NOS activity. Results also show that calmodulin may be involved in this process since its presence in the incubation medium prevents the inhibitory effect of melatonin on NOS activity.     

L-Ala-substituted rat galanin analogs distinguish between hypothalamic and jejunal galanin receptor subtypes

In order to explore which amino acids or which blocks of amino acids in the 29 amino acid neuropeptide galanin are important for recognition of the endogenous ligand by galanin receptor subtypes present in the jejunum and in the hypothalamus, respectively, we have carried out L-Ala substitutions of individual amino acids or of blocks of amino acids in the rat galanin sequence and examined the binding of the obtained analogs to the rat hypothalamic and jejunal galanin receptor subtypes. This study reveals that the galanin sequence YLLGPH^9–14 is essential for recognition of galanin by both the rat hypothalamic and jejunal galanin receptor subtypes. Substitution of the N-terminal amino acids, GWTL^1–4, leads to total loss of affinity of galanin for both hypothalamic and jejunal galanin receptors. The α-helical C-terminal amino acid (25–29) part of galanin has no greater influence on the affinity of galanin to the hypothalamic galanin receptor subtype. L-Ala substitution of the C-terminal amino acids of galanin KHGLT^25–29 shows, however, that this C-terminal motif is essential for the recognition by the jejunal galanin receptor subtype, whereas amino acids in the middle portion of galanin NSAG^5–8 are of importance for binding to the hypothalamic but not to the jejunal receptor. [Ala^5–8] Galanin thus has a more than 100-fold higher affinity to jejunal receptor than to the hypothalamic receptor, while [Ala^25–29] galanin has a more than 100-fold higher affinity for the hypothalamic than for jejunal galanin receptor subtypes. pH dependence of the galanin binding to these receptor subtypes is also different. © Munksgaard 1997.     

Arthroscopic all-inside repair techniques of lateral meniscus anterior horn tear: a technical note

Although the conventional outside-in technique is especially useful for repairing tears in the anterior portion of the meniscus, it has a disadvantage of making an additional 1–2 cm sized skin incision and tying knots subcutaneously over the capsule. Therefore we devised two all-inside repair techniques of lateral meniscus anterior horn tear according to the site of meniscal tear, meniscosynovial junction or red–red zone. Because these techniques are modified methods of the outside-in meniscal repair using a spinal needle, they are as simple as conventional outside-in technique. In addition they have advantages of vertical mattress suture, which is an important characteristic of the all-inside repair, and no additional incision. We recommend these techniques as an alternative method for repairing an anterior horn tear of the lateral meniscus.     

侧脑室引流术治疗脑室出血医院感染分析

目的 分析治疗脑室出血侧脑室引流术后感染发生率，探讨预防感染的方法及措施。方法 根据留管时间将患者分为甲、乙两组，按单侧引流及双侧引流分为A、B组，术后观察插管部位的感染发生情况，同时定期做血培养监测。结果 甲、乙组之间，经统计学处理P＜0．01，差异有高度显著性，A、B两组比较，P＞0．05，差异无显著性。结论 留管1～2周时间是安全的，超过2周，感染率上升，双侧引流术后感染率高于单侧引流者，此外，患者的全身状况及免疫力也与感染率明显相关。     

侧脑室脑膜瘤的诊断及显微手术治疗

目的 探讨侧脑室内脑膜瘤诊断特点及显微手术方法.方法 MRI和/或CT确诊并行显微手术切除侧脑室脑膜瘤24例,其中2例内窥镜辅助切除.肿瘤位于左侧三角区13例,右侧三角区7例,右侧体部1例,横跨双侧三角区1例,左侧颞角2例.顶枕入路15例,颞中回入路7例,经胼胝体后部入路2例.结果 24例影像学诊断与术后病理相符合,均给予全切.完整切除5例,分块切除19例.18例获得随访,完全正常10例,3例复发再次手术全切,癫痫2例,同向性偏盲3例.结论 CT和MRI是诊断侧脑室脑膜瘤的最可靠的手段,显微手术是目前侧脑室脑膜瘤的首选治疗方法.     

Correction of webbed-neck deformity in Turner's syndrome

Summary A case of Turner's syndrome with the typical marked webbing of the neck is presented. A posterior approach is preferred for correction of this webbed neck deformity. A butterfly shaped portion of excess skin is excised and the margins of the defect mobilised as four flaps. The flaps are sutured with a very short midline vertical component, resulting in an almost X-shaped scar. The first procedure resulted in only a partial correction of the deformity and an excess of hypertrophic scar tissue. This was treated with a repeat of the procedure but the midline wounds was repaired with mulitple small Z-plasties. The final appearance of the neck was satisfactory in the lateral profile, but there was still some excess tissue posteriorly.     

The lateral chest X-ray: Is it necessary for emergency department patients?

To determine the utility of the lateral view of the chest in emergency department patients, records of all patients who had had 2-view chest x-rays ordered in the emergency department were reviewed retrospectively. A study radiologist recorded a reading of the posteroanterior (PA) radiograph alone. The lateral radiograph was then provided, along with the PA view, and a second reading was recorded. A comparison was then made between the first and second readings.A total of 417 sets of x-rays were included. The PA view alone successfully diagnosed or suspected 92% of pulmonary nodules, 95% of effusions, 97% of cases of emphysema, 98% of pneumonias, and 100% of cases of cardiomegaly, pulmonary edema, interstitial pulmonary disease, and atelectasis.In the emergency department patient population, lateral views of the chest have minimal diagnostic yield and therefore may be used selectively to safely decrease the amount of breast radiation exposure to young women.     

Activity of lateral vestibular nucleus neurons during locomotion in the decerebrate Guinea pig

Summary The influence of locomotor activity upon neurons in the lateral vestibular nucleus was investigated in precollicularly-postmamillary decerebrate guinea pigs. Out of 95 recorded neurons, 24 were identified as vestibulospinal and 71 had no descending projections. Locomotor activity occurred either spontaneously or was prompted by electrical stimulation of the mesencephalic locomotor region. Natural vestibular stimulation was supplied by tilting the animal about its longitudinal axis. Locomotor rhythmic limb muscle activity was accompanied by an increase in the firing frequency in the vast majority of investigated neurons. The increase in frequency was observed at the beginning of ipsilateral forelimb extensor muscle activity. Only in a few non-vestibulospinal neurons was the spontaneous activity depressed during locomotion. An increase in evoked responses was observed in almost all vestibulospinal neurons and in two thirds of the neurons without descending projections. A decrease in evoked responses was observed in one quarter of non-vestibulospinal neurons. During locomotion, the mean and maximal frequencies of evoked neuronal impulse activity changed, but the phase lag of these changes was not altered significantly. The results suggest an enhancement of vestibulospinal influences during locomotion, thus providing a high level of tonus in antigravitational muscles. This is interpreted as a mechanism to ensure that equilibrium is maintained during motion in different gaits and postures.     

四季鹅下丘脑单位放电的研究

实验利用慢性微电极技术观察了清醒活动四季鹅(产蛋期鹅和休产期鹅)下丘脑细胞自发放电及第Ⅱ脑室注入去甲肾上腺素(NE)对单位放电的影响.结果表明无论是产蛋期鹅还是休产期鹅.其下丘脑放电均以中频为主,但产蛋期鹅高频放电高于休产期鹅.放电有单个连续、束状、组群式等3种形式,无论是产蛋期鹅还是休产期鹅,其下丘脑均以单个连续放电为主,但产蛋期鹅组群式放电高于休产期鹅.第Ⅱ脑室注入NE后,75%的单位放电数增加,25%的单位放电数减少.     

Recurrent sleep attacks associated with a craniopharyngioma

Symptomatic narcolepsy, once regarded as common, is now believed to be very rare. A 32-year-old man had a history of recurrent sleep attacks. A magnetic resonance imaging scan revealed a third ventricle tumor. The tumor was totally removed, and the histology was a craniopharyngioma. The symptoms ceased after the operation. The chronological correlation and the anatomical location of the tumor suggest that the patient had a symptomatic narcolepsy caused by the tumor. This is the first report that documents the cessation of narcolepsy attacks after tumor removal.