Urinary monoamine metabolites as indices of mental stress in healthy males and females

Concentrations of the serotonin metabolite 5-hydroxyindole acetic acid (5-HIAA), the dopamine metabolite homovanillic acid (HVA) and the noradrenaline metabolite 4-hydroxy-3-methoxyphenyl glycol (HMPG) were determined in urine samples from healthy male and female students by mass fragmentography. Urine samples were obtained after a demanding examination (mental stress) and a day of ordinary school work (control condition). Self-ratings were obtained of feelings induced by the examination, and of habitual psychosomatic symptoms. The results for both sexes showed that the examination stress induced a significant increase of HVA and HMPG excretion, but not of 5-HIAA. The males excreted significantly more of each of the metabolites than the females. The pattern of correlations between metabolite levels and psychological and psychosomatic variables were strikingly different for the two sexes.     

Alpha-tocopherol and beta-carotene do not protect marmosets against the dopaminergic neurotoxicity of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine

Idiopathic Parkinson's disease (PD) may possibly be caused by one or more unidentified neurotoxins present in the environment, or formed endogenously, which progressively damage dopaminergic nigrostriatal neurons. N-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is an experimental neurotoxin which produces biochemical and neuropathological changes in humans, lower primates and mice that closely resemble those found in PD. Because the mechanisms of neuronal damage in both idiopathic PD and in the MPTP model of PD may involve free radical formation in the substantia nigra, antioxidants might protect dopaminergic neurons. Previously, we found that both alpha-tocopherol and beta-carotene partially protected mice against MPTP. However, in the experiments described in this paper, neither alpha-tocopherol nor beta-carotene, each administered in massive doses, had any demonstrable protective effect for dopaminergic nigrostriatal neurons in marmosets injected with low doses of MPTP. Without more knowledge about the identity of the neurotoxin(s) causing idiopathic PD, and their mechanism of action, it is not possible at this time to predict whether these 2 antioxidants might be clinically useful in preventing or ameliorating PD.     

Intussesception after jejunoileal bypass as diagnosed by ultrasound

Eighty patients who had undergone jejunoileal bypass for morbid obesity were examined by ultrasound at their routine follow-up visits to the clinic. Ultrasonographic evidence of intestinal intussusception was found in 15 patients (19%). Two of these patients were asymptomatic. Ultrasonographic findings were confirmed by operation in 6 patients (5 with intussusception, 1 negative).     

The histomorphologic and morphometric study of asymptomatic hip arthroplasty. A postmortem study

The purpose of this study was to determine the histologic findings at the bone-cement interface in successful asymptomatic total hip replacements (THR) retrieved from patients at autopsy. The criteria for a successful hip arthroplasty were clinical, radiologic, and direct examination of the prosthesis at the time of harvesting. Twelve patients with a total of 14 cemented hip arthroplasties came to autopsy at a mean of 4.7 years after implantation. A detailed histomorphometric objective means of assessing the tissue response was applied to the membrane. The density of histiocytes correlated with the thickness of the membrane, the density of polyethylene particles, and the time after implantation. The fibrohistiocytic membrane in this group of patients was similar to that described in the literature in cases of loose THRs. These findings advance current understanding of transcellular particle transportation (directional exocytosis) in tissue reactions to endoprostheses of THR.     

MR pelvimetry--a practical alternative.

Pelvimetry remains a useful technique as part of the assessment of the term breech pregnancy where vaginal delivery is planned. MR pelvimetry is accurate, well tolerated and shows soft-tissue structures as well as bone. It avoids the potentially carcinogenic effects of ionising radiation and is thought to be completely safe for mother and fetus. A technique of MR pelvimetry is described which uses gradient-echo sequences. This quick, practical method makes minimal inroads into valuable scanning time, and may therefore be considered a potentially cost-effective alternative to conventional pelvimetry.     

Administration to humans of ORG 21465, a water soluble steroid i.v. anaesthetic agent

Ten male volunteers received a 1-min i.v. infusion of a new water soluble steroid anaesthetic agent, ORG 21465. Individuals received doses ranging from 0.8 to 1.8 mg kg-1. All subjects experienced venous pain at the site of injection; those receiving 1.0 mg kg-1 or more became anaesthetized. There was no evidence of histamine release and apnoea did not occur. Excitatory phenomena were observed in all subjects and were dose related; no spikes were seen on the EEG. Pharmacokinetic analysis supported a three-compartment (non-weight- related) model with compartmental volumes V1, V2 and V3 of 4.31, 14.2 and 89.4 litre, respectively. Clearance from the central compartment V1 was 1.55 litre min-1. Inter-compartmental clearances Q1 and Q2 were 2.54 and 1.79 litre min-1. We found that ORG 21465 was an effective anaesthetic in humans. The relationship between sedation, anaesthesia and excitation requires further exploration.      

Cardiovascular evaluation in Turner syndrome: utility of MR imaging.

Forty patients with karyotypically proven Turner syndrome were prospectively studied using magnetic resonance imaging (MRI) and echocardiography in order to determine the frequency of cardiovascular anomalies and to assess the utility of both imaging modalities as methods for cardiovascular evaluation in Turner syndrome. Cardiovascular anomalies were found in 45% of patients. A high absolute prevalence of bicuspid aortic valve (17.5%) and aortic coarctation (12.5%) were observed relative to comparable series. Of clinically significant abnormalities, three of five aortic coarctations and four of five ascending aortic dilatations were solely MRI detected and not evident at echocardiographic examination. MRI is thus seen as a valuable adjunct to echocardiography in the cardiovascular evaluation of Turner syndrome patients. The usefulness of MRI primarily relates to its ability to provide excellent visualisation of the entire thoracic aorta where a large proportion of clinically significant anomalies occur in Turner syndrome.