Medial temporal lobe epilepsy associated with misplacement of a ventricular shunting catheter

We report the case of a 35-year-old woman who developed right medial temporal lobe epilepsy associated with misplacement of a ventricular shunting catheter in the apex of the right temporal lobe. At 8 years of age, the patient had undergone total removal of a cerebellar astrocytoma and placement of a Torkildsen's ventriculo-cisternal shunt for obstructive hydrocephalus. Although the postoperative course was uneventful, she developed medically intractable psychomotor seizures with secondary generalization at 24 years of age. CT revealed that the tip of the shunting catheter was misplaced in the apex of the right temporal lobe, through the posterior and inferior horn of the right lateral ventricle. Intraoperative electrocorticography revealed frequent paroxysmal activity in the hippocampus, so hippocampectomy as well as removal of the shunting catheter was performed. Postoperatively, the patient became seizure-free, and pathological examination revealed hippocampal sclerosis.     

Vasoconstricting effect of angiotensin II in human hand veins: influence of aging, diabetes mellitus and hypertension.

We examined human hand veins to determine whether venoconstricting response to angiotensin II (Ang II) and noradrenaline (NA) was influenced by aging or such diseases as diabetes mellitus (DM) and hypertension (HT). Twenty healthy male subjects (20-73 years), and 8 male patients with non-insulin-dependent DM and 8 male patients with essential HT were included in this study. A constant dose (50 ng/min) of Ang II or increasing dose (2-256 ng/min) of NA was infused into the dorsal hand vein and its diameter was measured using a linear variable differential transformer. The constant infusion of Ang II caused rapid desensitization or tachyphylaxis. The venoconstriction by Ang II in the 8 elderly subjects (58 to 73 years) was significantly (p<0.05) larger than that in the 8 young subjects (20 to 36 years) from 6 to 18 min after the start of the infusion (after 6 min: 63.6+/-11.6 (mean+/-SD)% vs. 39.9+/-20.8%, 12 min: 34.0+/-11.9% vs. 12.0+/-12.0%). However, the venoconstriction by Ang II in the patients with DM or HT was not significantly different from that in the 9 age-matched control subjects. No significant difference in venoconstrictor response to NA was observed between the young and elderly subjects, nor between the control subjects and the patients with DM or HT. These findings indicated that venoconstrictor response to Ang II might be greater in the elderly but might not be influenced by DM nor HT.     

Clinical, histological, and immunohistological studies of postoperative erythroderma

We report 7 cases of acute fatal illness characterized by fever, diffuse erythematous rash, and progressive leukopenia occurring 10 days after surgical operation. The outcome was uniformly fatal. The biopsy findings consisted of eosinophilic individual necrosis of epidermal cells, satellite cell necrosis, basal liquefaction degeneration, and scanty cell infiltration into the dermis. T lymphocytes were found in the epidermis but Langerhans cells disappeared. These findings are compatible with acute graft-vs-host disease following blood transfusion. Explanations based upon drug allergy, infection, toxic shock syndrome, or toxic epidermal necrolysis seem less reasonable.     

Comparative pharmacokinetics of oral 6-mercaptopurine and intravenous 6-mercaptopurine riboside in children

BACKGROUND: The poor absorption of orally administered 6-mercaptopurine (6MP) causes a wide variation in its cytotoxic efficacy. An i.v. dosage form would eliminate this problem. Our objective was to compare the pharmacokinetics of 6MP administered orally with those of an i.v. dosage form 6-mercaptopurine riboside (6MPR), in children with acute lymphoblastic leukemia or malignant lymphoma. METHODS: A total of 10 children were treated with oral 6MP, 50 mg/m(2) per day, while five children were treated with 6MPR, 50 mg/m(2) per day, administered by rapid i.v. injection. The plasma concentrations of 6MP and of 6MPR were measured on day 0, while the concentrations of 6-thioguanine nucleotides (6TGN) in red blood cells (RBC) were measured on day 2. The area under the plasma concentration-time curve (AUC1-5) was calculated from 1 to 5 h after drug administration. RESULTS: With the intravenously administered 6MPR, the AUC1-5 ranged from 124 to 186 (1.5-fold range, median 145) microM min; only two samples were obtained for the RBC concentration of 6TGN, and were 121 and 273 pmol per 25 mg hemoglobin. With the orally administered 6MP, the AUC1-5 ranged from 23 to 65 microM min (2.8-fold range, median 56); the RBC concentration of 6TGN ranged from 18 to 152 pmol per 25 mg hemoglobin (median 75). CONCLUSION: The i.v. administration of 6MPR showed less interindividual variation in the AUC1-5 coupled with a higher RBC level of 6TGN as compared with those by oral 6MP. We conclude that the i.v. administration of 6MPR achieves stable blood levels of active drug in children undergoing cancer chemotherapy.     

Pathogenesis of acne

Acne vulgaris is a skin disorder of the sebaceous follicles that commonly occurs in adolescence and in young adulthood. The major pathogenic factors involved are hyperkeratinization, obstruction of sebaceous follicles resulting from abnormal keratinization of the infundibular epithelium, stimulation of sebaceous gland secretion by androgens, and microbial colonization of pilosebaceous units by Propionibacterium acnes, which promotes perifollicular inflammation. The clinical presentation of acne can range from a mild comedonal form to severe inflammatory cystic acne of the face, chest, and back. At the ultrastructural level, follicular keratinocytes in comedones can be seen to possess increased numbers of desmosomes and tonofilaments, which result in ductal hypercornification. The increased activity of sebaceous glands elicited by androgen causes proliferation of P. acnes, an anaerobe present within the retained sebum in the pilosebaceous ducts. The organism possesses a ribosome-rich cytoplasm and a relatively thick cell wall, and produces several biologically active mediators that may contribute to inflammation, for instance, by promoting leukocyte migration and follicular rupture. In inflamed lesions, numerous neutrophils and macrophages infiltrate around hair follicles and sometimes phagocytose P. acnes. To examine the participation of neurogenic factors in the pathogenesis of acne, we quantitatively assessed the effects of neuropeptides on the morphology of sebaceous glands in vitro using electron microscopy. Substance P, which can be elicited by stress, promoted the development of cytoplasmic organelles in sebaceous cells, stimulated sebaceous germinative cells, and induced significant increases in the area of sebaceous glands. It also increased the size of individual sebaceous cells and the number of sebum vacuoles for each differentiated sebaceous cell, all of which suggests that substance P promotes both the proliferation and the differentiation of sebaceous glands. In this review, we introduce the general concept of pathogenic factors involved in acne, including typical electron microscopic findings and recent evidence of stress-induced exacerbation of acne from a neurological point of view. An improved understanding of the pathogenesis of acne should lead to a rational therapy to successfully treat this skin disease.     

Fusobacterium necrophorum haemolysin stimulates motility of ileal longitudinal smooth muscle of the guinea-pig

Fusobacterium necrophorum haemolysin (0.5-3.1 mg protein/mL) dose-dependently induced contractions of the isolated ileal longitudinal smooth muscle of the guinea-pig. The haemolysin (3.1 mg protein/mL) -induced maximum contraction of 75% of the response to 60 mM K+ declined within 17 min and the muscles then demonstrated rhythmic contractions. Tetrodotoxin (3.1 x 10(-6) M) had no effect on the contraction due to the haemolysin. After incubation in Ca(2+)-free medium, the ileal response to the haemolysin was lost. Verapamil, a Ca2+ channel blocker, dose-dependently inhibited the contraction to the haemolysin. The rabbit anti-serum against F. necrophorum haemolysin inhibited the haemolysin-induced contraction of ileal muscle. The bacterial haemagglutinin and the lipopolysaccharide had no effect on the response of ileal muscle. These findings suggest that the haemolysin-induced direct stimulation of ileal motility dependant on Ca2+ influx will increase the probability of contact of F. necrophorum and ileal mucosa and could increase the chances of colonization for F. necrophorum.