The effects of administration of an inhibitory GABAergic or excitatory glutaminergic neurotransmitter into the lateral hypothalamic area (LHA) on gastric acids, an aggressive mechanism, and transepithelial potential difference (PD) and mucosal blood flow (MBF), defensive mechanisms, were examined in anesthetized rats, since lesions of LHA in these animals cause gastric mucosal damage and electrical stimulation stimulates gastric acids and antral contractions. Microinfusion of the inhibitory neurotransmitter, muscimol (GABA agonist) resulted in an increase in gastric acid secretion and in PD and MBF. The GABA antagonists picrotoxin and bicuculline methiodide, in contrast, decreased these three factors. The excitatory neurotransmitter L-glutamate induced only an increase of MBF. Thus, the GABAergic system in LHA stimulates the gastric functions, both defensive and aggressive mechanisms, while the glutaminergic system increases only a portion of the defensive system. The results suggest that there is a significant interaction between LHA and stomach functions.

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Role of the efferent and afferent vagus nerve in the development of ventromedial hypothalamic (VMH) obesity.

Hyperactivity of the vagus nerve and hypoactivity of the sympathetic nerves after VMH lesions both cooperatively contribute to the development of VMH obesity, mainly through hyperinsulinemia. Recently it has turned out that we should discriminate the role of the efferent vagus from that of the afferent vagus in the pancreatic hormone secretion. The hepatic branch is the main pathway of afferent fibers in the vagus, while the celiac (pancreatic) branch is the main pathway of efferent fibers. We investigated the role of the afferent and efferent vagus on the development of VMH obesity using the sectioning of the hepatic and celiac branch. Celiac vagotomy decreased insulin secretion and food intake, while hepatic vagotomy did not change them. The results suggested that the efferent vagus plays the main role in the development of VMH obesity, while the role of afferent vagus seems less apparent.

Afferent Pathways↗

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Histologic examination of dislocated lenses.

PURPOSE: To examine histological changes resulting from dislocated and subluxated lenses. CASES: The subjects consisted of 16 patients (aged 52-89 years) who underwent total lens extraction for lens dislocation or subluxation in the Department of Ophthalmology at Fukui Medical University during the period between April 1991 and June 1998. There were 5 patients (6 eyes) with traumatic dislocation and 11 patients (11 eyes) with idiopathic dislocation. RESULT: Rupture of the cortical fibers and migration of the epithelial cells toward the posterior pole of the lens were more frequently noted in patients with traumatic dislocation than in the idiopathic group, and both findings were often simultaneously observed. Rupture of the cortical fibers was considered attributable to external pressure transmitted to the lens. CONCLUSION: We speculate that the concurrent migration and dislocation of the equatorial bow architecture toward the posterior pole was caused by inhibition of differentiation of the epithelial cells to fiber cells by external pressure on the equatorial region.

Aged↗

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Immunohistochemical study of apoptosis of lens epithelial cells in human and diabetic rat cataracts.

PURPOSE: To evaluate apoptosis of lens epithelial cells by immunohistochemical methods. METHODS: We performed terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assays on capsulotomy specimens (53 patients, 68 eyes) from patients who had undergone cataract surgery, and on the epithelium of diabetic cataracts in rats (72 rats, 144 eyes). An animal model of diabetic cataracts was prepared by injection of streptozotocin in 3-week-old rats. The specimens of rats were also examined using the proliferating cell nuclear antigen (PCNA) immunohistochemical staining method. RESULTS: Although some TUNEL-positive cells were detected in capsulotomy specimens, we recognized little correlation between their distribution and the morphological classification of the cataracts. In the animal model of diabetic cataracts, TUNEL-positive cells were seen around the regions of accumulated epithelial cells. In the accumulated regions, PCNA-labeled cells undergoing DNA synthesis were also detected. CONCLUSIONS: These results suggest the possibility that apoptosis occurs in human lens epithelial cells. Apoptosis and proliferation of lens epithelial cells may be induced by factors such as hyperglycemia.

Aged↗

PubMedDate not supplied

Disruption of the blood-brain barrier caused by nonionic contrast medium used for abdominal angiography: CT demonstration.

We describe a case of disruption of the blood-brain barrier (BBB) by nonionic, low osmolality contrast medium after abdominal angiography. One plausible explanation of this event is that acute hypertension during angiography may have increased the BBB permeability, allowing the contrast medium to leak across it.

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