Myelographic study of the spinal cord ascent during fetal development

To assess the length of the spinal cord relative to the vertebral column during fetal development, we performed translumbar myelograms on 340 spontaneously aborted fetuses. Of these, 146 were selected for study. There were 76 males and 70 females, with fetal age ranging from 7 to 33 weeks. Significant variation in the level of spinal cord termination was found in fetuses between 12 and 25 weeks gestational age. In fetuses between 25 and 33 weeks gestational age, the cord ended at or above the third lumbar vertebra.     

Chronic withdrawal of a high-palatable obesity-inducing diet completely reverses metabolic and vascular abnormalities associated with dietary-obesity in the rat

Chronic consumption of a high-palatable diet induces obesity and markedly impairs arterial relaxation. We have recently reported that endothelial function is only partially resorted after acute withdrawal of palatable diet. Therefore, this study was designed to investigate the effects of chronic withdrawal of high-palatable obesity-inducing diet on metabolic and vascular function in rats. Wistar rats were fed either standard laboratory chow throughout (controls) or given a highly-palatable diet (diet-fed) for 15 weeks; or fed the diet for 8 weeks and then returned to chow (diet-to-chow) for further 7 weeks before sacrifice. Diet-fed rats had higher body weight, fat mass, liver and heart weight than both chow-fed and diet-to-chow groups (P<0.01 for all). Compared with chow-fed and diet-to-chow groups, diet-fed rats had significantly raised fasting plasma levels of insulin, leptin and triglycerides levels (each +180%; P<0.0001), but not glucose or non-esterified fatty acids. There were no significant differences between any metabolic parameters between chow-fed and diet-to-chow groups. Mesenteric arteries showed no significant differences between any groups in KCl-induced tension generation, while diet-fed groups had significantly higher noradrenaline-induced vasoconstriction than both chow-fed and diet-to-chow groups. Maximum endothelial-dependent vasorelaxation responses to carbamylcholine (CCh) were significantly (by 23%; P<0.001) attenuated in the diet-fed group. This defect was abolished in the diet-to-chow group. There were no significant differences in endothelium-independent vasorelaxation responses to sodium nitroprusside between the three groups. In conclusion, palatable diet induces obesity and metabolic abnormalities as well as a marked endothelial dysfunction. These abnormalities are completely reversed by chronic withdrawal of the obesity-inducing high-palatable diet.     

Protective effect of red grape seeds proanthocyanidins against induction of diabetes by alloxan in rats.

It has been documented that impaired homeostasis in diabetes mellitus is associated with increased production of reactive oxygen species and depletion of the antioxidant defense systems. Natural grape seed proanthocyanidins (GSP) are potent free radical scavengers and hence provide significant protection against oxidative stress. Accordingly, the present study focused on investigating the possible protective role of GSP against free radical-mediated damage in pancreatic tissues of alloxan-induced diabetes in rats. The results revealed that oral administration of 50 and 100 mg kg(-1) (body weight) of GSP for 72 h significantly increased pancreatic glutathione (GSH) levels and inhibited the increase in lipid peroxidation caused by alloxan (p < 0.001). On the other hand, a significant reduction in pancreatic total nitrate/nitrite content (p < 0.001) was observed. Furthermore, GSP caused significant decline in the hyperglycemia induced by alloxan (p < 0.001). Such antihyperglycemic effect of GSP was accompanied by a significant increase in serum insulin levels in diabetic rats following 72 h of administration (p < 0.001). In conclusion, the study suggests that GSP are effective in ameliorating the damage to pancreatic tissue in experimental diabetes mellitus. Such effect may be related to their potent antioxidant properties as evidenced by the increase in pancreatic GSH and reduction of lipid peroxidation as well as total nitrate/nitrite levels.     

The effects of lignocaine on actions of the venom from the yellow scorpion “Leiurus quinquestriatus” in vivo and in vitro

Fatani, A.J., Harvey, A.L., Furman, B.L., and Rowan, E.G. The effects of lignocaine on actions of the venom from the yellow scorpion, Leiurus quinquestriatus, in vivo and in vitro. Toxicon, 19. Many toxins from scorpion venoms activate sodium channels, thereby enhancing neurotransmitter release. The aim of the present work was to determine if the in vivo and in vitro effects of Leiurus quinquestriatus venom (LQQ) could be ameliorated by lignocaine, a sodium channel blocker. In urethane anaesthetised rabbits, LQQ venom (0.5 mg kg⁻¹, i.v.) caused initial hypotension and bradycardia followed by hypertension, pulmonary oedema, electrocardiographic changes indicating conduction defects, ischaemia, infarction, and then hypotension and death. Lignocaine (1 mg kg⁻¹ i.v. bolus initially, followed by i.v. infusion of 50 μg kg⁻¹ min⁻¹) significantly attenuated the majority of the venom-evoked effects and reduced mortality. Addition of LQQ venom (1, 3 and 10 μg ml⁻¹) to chick biventer cervicis, guinea pig ileum, and rat vas deferens preparations, increased the height of electrically-induced twitches, elevated resting tension, and caused autorhythmic oscillations. Lignocaine (3 × 10⁻⁴–1.2 × 10⁻³ M) greatly attenuated these venom-evoked actions in the three preparations. Antagonists of appropriate neurotransmitters were also tested to determine the contribution of released transmitters to LQQ effects. Atropine significantly decreased the venom-elicited effects on guinea pig ileum preparations, while prazosin and guanethidine significantly reduced the venom’s actions on rat vas deferens. In chick biventer cervicis preparations, tubocurarine and hexamethonium significantly attenuated the venom-induced effects. This study supports the hypothesis that many effects of LQQ venom involve the release of neurotransmitters and may be ameliorated by treatment with lignocaine.     

Methotrexate neuroenteropathy--a histochemical study

10 mg/kg Methotrexate was injected daily for 5 d a week for a total period of 3 weeks and its effect on autonomic nerve profiles of jejunum was studied using histochemical methods. Initially (after 5 doses in a week) partial degeneration of adrenergic and cholinergic nerve supply was observed. Prolonged treatment (15 does in 3 weeks) was responsible for disappearance of about 30% of adrenergic and 50% of cholinergic nerve profiles. Early degenerative changes in the cholinergic nerve cells of the intestinal plexuses was also noted.     

Myofibroblastoma of the mandible in a 3-year-old child

Myofibroblastoma is a rare benign tumor of the head and neck region, which is characterized by a large, rapidly growing, and destructive mass. A 3-year-old boy presented with an 8-week history of a rapidly growing swelling of the right mandible. Examination revealed a firm 13-cm mass occupying the entire right body and ramus of the mandible. The clinical and radiological features were suggestive of a sarcoma. An initial biopsy taken in the referring hospital was inconclusive, and the second biopsy showed a myofibroblastic neoplasm consistent with a desmoplastic fibroma. Progressive tumor growth necessitated a tracheostomy. Right hemimandibulectomy was performed, and the defect was reconstructed with free microvascular fibula flap. Histopathology and immunocytochemistry revealed a myofibroblastoma. This entity differs from other myofibroblasts and fibroblast tumors such as inflammatory myofibroblastic tumor (IMT), myofibroma, and desmoplastic fibroma. The child has been followed up for 2 years. Conclusion: Differentiation between myofibroblasts and fibroblastic tumors as well as some malignancies can be challenging. Myofibroblastoma can behave as a malignant neoplasm, and the clinical distinction of this entity lies primarily in its recognition as a benign neoplasm.     

Histological changes following high-dose methotrexate and cisplatinum administration and the influence of dosage scheduling

Histological changes were studied in experimental animals following the intraperitoneal administration of high-dose cisplatin with or without high-dose methotrexate and citrovorum factor. There were pronounced renal toxicities with high-dose (10 mg/kg) cisplatin, particularly involving distal tubules with glomerular congestion. However, lower toxicities were noted with reduced dosage of cisplatin (5 mg/kg) and especially if given once as a single bolus injection instead of a 5-day regimen. Renal and hepatic toxicities were marked with concomitant methotrexate administration leading to hemorrhagic diathesis and shorter survival. However, toxicities were relatively reduced when cisplatin was given as a single bolus injection instead of a 5-day divided course. Such information may prove helpful in future planning of combination chemotherapy in patients with malignancies using these two agents.     

Irradiation of Langmuir-Blodgett multilayer preparations of phospholipids and a fatty acid. 2: Effect of X-radiation.

X-irradiation of Langmuir-Blodgett (LB) preparations of stearic acid with doses up to a few thousand Gy produced no change of measured electrical conductance in the direction perpendicular to the stacked monolayers. However, irradiation of LB preparations of phospholipids resulted in increased conductance. The effect depended on dose, but not on dose rate and, unlike the corresponding effect of UV-radiation, did not reverse at room temperature. For doses up to about 2 kGy the increased conductance fell away over some tens of minutes if the temperature was raised above 45 degrees C. For doses between 2 and 60 kGy the conductance increased linearly, but less rapidly than the initial rise and the increase was only partly reversible by heating. The rate of increase of conductance rose again for doses above about 60 kGy and for these doses the increase could not be reversed on heating. It is suggested that X-irradiation left molecules in a damaged but reversible state similar to that found after UV irradiation; and that subsequent excitation and ionization damaged the molecules irreversibly.