Treatment of Raynaud's phenomenon with triiodothyronine corrects co-existent autonomic dysfunction: preliminary findings.

Cardiovascular autonomic function was assessed in 9 subjects with Raynaud''s phenomenon. The underlying diseases were systemic lupus erythematosus (n = 5), systemic sclerosis (n = 3) and rheumatoid arthritis (n = 1). Five standard non-invasive tests, 3 of heart rate and 2 of blood pressure, were employed. Compared with age and sex matched controls (n = 25), the number of values abnormal was 24 of 45 (53%) overall and between one and 4 (median, 2) individually. Significant differences were present for 3 tests, two of heart rate and one of blood pressure. The subjects were given triiodothyronine, 60 to 80 micrograms per day, for vasospastic attacks. Autonomic function was reassessed between weeks 4 and 9 (9 subjects) and between weeks 12 and 18 (8 subjects) after introduction of triiodothyronine. Test results showed a considerable improvement. At the second reassessment, the number of values abnormal was now 5 of 40 (12.5%) overall and nil (n = 4) or one (n = 4) individually. Significant differences remained for one heart rate test only. Adverse side effects to triiodothyronine occurred in a single subject and were readily controlled. Evidence of somatic neuropathy was present electrophysiologically in all 9 subjects and clinically in 8. Triiodothyronine may have corrected autonomic dysfunction by increasing blood flow to ischaemic peripheral nerves or by acting on the autonomic system more directly. Further study of triiodothyronine in autonomic insufficiency appears merited.     

Dose-dependent kinetics of the enantiomers of MK-571, an LTD4-receptor antagonist

Summary The disposition of the enantiomers of MK-571 (MK-0679 and L-668,018) following single i. v. doses of MK-571 (L-660,711) was studied in a three way cross-over study in 12 healthy male volunteers. Each volunteer received 75 mg, 300 mg and 600 mg i. v. doses of MK-571 at weekly intervals.The disposition of both enantiomers appeared dose-dependent, since the AUC increased disproportionately faster than the dose. The dose dependency was much more pronounced for L-668,018: its AUC increased 6-fold from the 75 to the 300 mg dose, 16-fold from 75 to 600 mg and 2.7 fold from 300 to 600 mg. For MK-0679, the corresponding increases in AUC were 4.8-, ll-, and 2.3 fold. Regardless of dose, the elimination of L-668,018 was more rapid than that of MK-0679.The disposition of MK-0679 needs to be investigated independently to detect any potential influence of L-668,018 on its disposition.     

Dual-energy X-ray absorptiometry of lumbar vertebrae: relative contribution of body and posterior elements and accuracy in relation with neutron activation analysis.

The bone mineral content of 34 lumbar vertebrae obtained from ten cadavers (three men, seven women; age 61-88 years) was measured using a pulsed source dual-energy X-ray absorptiometry (DEXA) apparatus. Scanning was performed in the frontal projection and was repeated on the vertebral bodies obtained after removal of the posterior elements of the vertebrae. Subsequently a nondestructive neutron activation analysis (NAA) was performed. The mineral content of the vertebral bodies was found to represent (mean, SEM) 53.0% (1.9%) of the content of the whole vertebrae. The mineral content of the vertebral bodies assessed with NAA (BMC NAA) and with DEXA (BMC DEXA) showed a high correlation: BMC NAAA = (1.016 x BMC DEXA) + 0.990 r = 0.949 (p less than 0.001). We conclude that the mineral content of lumbar vertebral bodies can be accurately measured in vitro in a water environment by DEXA, and that the mean contribution of the posterior elements of the vertebra to the calcium hydroxyapatite content of whole vertebrae measured in the frontal projection is as high as 47.0%.     

Coccidioidal peritonitis associated with continuous ambulatory peritoneal dialysis

We report the first three cases of peritonitis due to the fungus Coccidioides immitis occurring during continuous ambulatory peritoneal dialysis (CAPD). At the time of diagnosis, none of the patients had evidence of active infection outside of the peritoneal cavity. Clues suggesting the diagnosis including a previous history of pulmonary coccidioidomycosis, an excess number of eosinophils in the peritoneal fluid, and failure to respond to therapy directed against bacteria. C immitis in peritoneal fluid was more readily isolated on specific fungal culture media than on routine bacterial culture media. In no instances did potassium hydroxide (KOH) preparations of the fluid reveal fungi. Coccidioidal peritonitis during CAPD appears to be a localized form of extrapulmonary coccidioidomycosis that has a relatively benign course once the peritoneal catheter is removed.     

Fractures of the atlas: classification, treatment and morbidity

Fractures of the atlas vertebra are generally considered to be innocuous injuries. A review of 35 patients with C1 fractures treated in the Acute Spinal Cord Injury Unit of Shaughnessy Hospital indicated that long-term morbidity is not as low as was previously thought. Thirteen of 23 patients (56%) followed up a minimum of 1 year post-trauma had significant symptoms of scalp dysesthesia, neck pain, and/or neck stiffness. A classification is presented, and the results of treatment modalities used are reviewed. Based on the findings, the simplest orthosis consistent with appropriate treatment of any of the often associated other spine fractures is recommended. Surgery is reserved for late instability or pain.     

Cerebral involvement in children with acute and relapsing inflammatory polyneuropathy

We present two children with seizures and other signs of cerebral involvement at the outset of acute inflammatory demyelinating polyneuropathy, consistent with a diagnosis of encephalomyeloradiculoneuropathy. One child had a recurrence associated with mild central dysfunction and improved during therapy with corticosteroids. Both children recovered completely. Both acute and relapsing inflammatory demyelinating neuropathy may be accompanied by cerebral dysfunction, expanding the clinical spectrum of encephalomyeloradiculoneuropathy.     

Myeloradiculopathy associated with wasp sting

A 12-year-old girl developed a reversible myeloradiculopathy 1 week after a wasp sting. Delayed neurologic hypersensitivity reactions to Hymenopteran stings occur primarily in adults. Reactions involving both the peripheral and central nervous systems are extremely rare and have never been reported in a child. The mechanisms underlying this uncommon reaction may be related to age-dependent differences in immunologic responses.     

Alterations in the cortical thymic epithelium of rats after in vivo exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD): an (immuno)histological study.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces thymic atrophy in rats. The present study was initiated to provide (immuno)histological data on the mechanism of action. Juvenile male Wistar rats were orally intubated once with 50 or 150 micrograms/kg TCDD. They were euthanized 4 or 10 days thereafter, or were allowed to stay alive until Day 20 or 26. Growth retardation occurred rapidly in all TCDD-treated animals. Lethality was demonstrated within 20-21 days after administration. At Days 4 and 10 after intubation, thymic atrophy was shown by reduction of thymic weight and cortex/medulla ratio. Staining patterns for T-cell markers in the atrophic thymuses coincided with the reduction of cortical areas. There was no evidence indicating that the effects were indirectly caused by stress. TCDD-induced thymic atrophy persisted until Day 26 after administration. Immunohistochemical analysis revealed prominent changes in the cortical thymic epithelium at the 150-micrograms/kg dose level. First, in the cortex epithelial cell aggregates were observed both at Day 4 and at Day 10 after administration. Apparently, the architecture of the epithelium had changed in these animals. Second, at 10 days after administration epithelial cells were found with the simultaneous expression of markers that in the normal uninvoluted thymus only occur either in the subcapsular/medullary area or in the cortex. This phenotype points to an unusual stage of differentiation. We conclude that TCDD exposure affects the cortical epithelium of the rat thymus at a high dose level. Apparently, it disturbs the epithelial network and interfers with the differentiation of epithelial cells.