Combining clinical judgement and statistical data in expert systems: Over-the-telephone management decisions for critical congenital heart disease in the first month of life

When a new-born baby with congenital heart disease is referred to a regional specialist centre, the transportation management is crucial but must be decided on the basis of clinical information obtained over the telephone. We consider algorithmic and naive statistical approaches to helping in this decision, and on the basis of preliminary results the relative strengths and weaknesses are discussed. A synthesised logical and probabilistic approach appears to have the best potential and could be implemented on hand-held computers.Paper presented at symposium on Computer-assisted Decision Support and Database Management in Anaesthesia, Intensive Care and Cardio-pulmonary Medicine, Rotterdam, 1988.     

Sexual harassment at work: issues and answers for health care administrators

Sexual harassment is not new to the health care industry. What is new is that recent media attention has heightened awareness that sexual harassment is illegal. This fact, coupled with the substantial liability that employers may incur if they fail to control sexual harassment, mandates the need for outlining the major issues relative to sexual harassment in today's health care setting. This article gives particular emphasis to the fact that sexual harassment can be prevented by taking a proactive stance.     

Use of Sequentially Administered Stable Lead Isotopes to Investigate Changes in Blood Lead during Pregnancy in a Nonhuman Primate (Macaca fascicularis)

The effects of pregnancy on the flux of lead from maternal bonewere investigated in five females from a unique colony of cynomolgusmonkeys (Macaca fascicularis) which had been dosed orally withlead (approximately 1100–1300 µg Pb/kg body wt)throughout their lives (about 14 years). Through the use ofstable lead isotopes ²⁰⁴Pb, ²⁰⁶Pb, and ²⁰⁷Pb, it was possibleto differentiate between the lead contributed to blood leadfrom the skeleton and the lead contributed from the currentoral dose. Blood samples and bone biopsy samples taken before,during, and after pregnancy were analyzed for lead (total andstable isotope ratios) by thermal ionization mass spectrometry.Through the use of end-member unmixing equations, the contributionto blood of lead from maternal bone during pregnancy was estimatedand compared to the contribution of lead from maternal bonebefore pregnancy. A 29 to 56% decrease in bone lead mobilizationin the first trimester was followed by an increase in the secondand third trimesters, up to 44% over baseline levels. In onemonkey, the third-trimester increase did not reach baselinelevels. In a single low-lead monkey, a similar decrease in thefirst trimester was followed by a 60% increase in the thirdtrimester, indicating that a similar pattern of flux is seenover a wide range of lead concentrations. Analysis of maternalbone and fetal bone, brain, liver, and kidneys confirmed a substantialtransplacental transfer of endogenous lead. Lead concentrationsin fetal bone often exceeded maternal bone lead concentrations.From 7 to 39% of the lead in the fetal skeleton originated fromthe maternal skeleton.     

Phase II studies of Elsamitrucin in breast cancer, colorectal cancer, non-small cell lung cancer and ovarian cancer

PURPOSE:: To test the antitumor activity of Elsamitrucin in metastaticcancer of the breast, colon and rectum, non-small cell lungand ovary. PATIENTS AND METHODS:: Eligibility required histologically proven cancer. Patientswith colorectal or non-small cell lung cancer could not havereceived prior chemotherapy. Patients were entered if WHO PSwas 2 and organ functions were normal. Treatment consisted ofElsamitrucin 25 mg/m²/week given as a 5–10 min infusionfor at least 3–6 weekly doses. RESULTS:: One hundred and five patients entered the studies, 97 were eligible,94 are evaluable for toxicity and 75 for response. Toxicitymainly consisted of mild nausea/vomiting, and less frequentlyreversible hepatotoxicity and malaise. No objective responseswere seen. CONCLUSION:: Elsamitrucin at this dose and schedule is not an active drugin metastatic breast cancer, colorectal cancer, non-small celllung cancer or ovarian cancer. Elsamitrucin, phase II, breast, colorectum, nonsmall cell lung, ovary     

Long-lasting increase in anxiety after electrolytic lesions of the pedunculopontine tegmental nucleus.

This study examined the effect of electrolytic lesions of the pedunculopontine tegmental nucleus (PPTg) on emotionality in rats. Rats with PPTg or sham lesions were tested in the elevated plus-maze, the social interaction test, the open-field test, and the conditioned fear paradigm. Histology showed that lesions were concentrated on the caudal half of the PPTg. In the plus-maze, behavioral scores were biased toward increased "anxiety" on the 1st testing day. Five consecutive exposures to the apparatus led to marked habituation in sham-lesioned but not in PPTg-lesioned rats. On the 5th day, most indexes of emotionality indicated elevated anxiety in PPTg-lesioned rats. Increased anxiety was also found in PPTg-lesioned rats in the social interaction test. In the conditioned fear paradigm, movement suppression during the postconditioned stimulus period was found in both groups on the 1st day of extinction but only in PPTg-lesioned rats on the 2nd extinction day, indicating extinction was slower in PPTg-lesioned rats. Lesions of the caudal PPTg appear to produce long-lasting anxiety in rats.     

Understanding CNS remyelination: clues from developmental and regeneration biology.

A guiding principle in remyelination research has been to seek clues to its nature in developmental studies on myelination. This "recapitulation hypothesis" argues that the regenerative response involves rerunning much the same programme as occurs during the developmental process. Here we examine the extent to which current evidence supports this hypothesis and whether this is a useful conceptual framework within which to study remyelination and suggest that an equally fruitful approach is to look to regenerative processes in other tissues.     

Dietary intakes of polyunsaturated fatty acids and indices of oxidative stress in human volunteers.

OBJECTIVE: To assess whether nutritionally-relevant changes in polyunsaturated fatty acid (PUFA) intake alter indices of oxidative stress in human volunteers DESIGN: A split plot/change over dietary study where half the volunteers consumed a diet containing 5% PUFA (low PUFA) as food energy for 4 weeks and after a 6 week washout period consumed a 15% PUFA (high PUFA) diet for another 4 weeks. The second group of volunteers completed this protocol in reverse. Total fat, carbohydrate, protein and vitamin E contents of the diets were constant. SUBJECTS: 10 healthy, non-smoking, male volunteers aged 32.6 +/- 1.7 y RESULTS: There was a significant increase in whole blood oxidised glutathione (P < 0.05), an index of oxidative stress, after consumption of the high PUFA diet. Moreover, urinary thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation, significantly increased (P = 0.038) following consumption of the high PUFA diet and decreased (P = 0.031) after consuming the low PUFA diet. However, there was no change in non specific plasma indices of lipid peroxidation, conjugated dienes and TBARS, nor in red cell antioxidant enzymes glutathione peroxidase, glutathione reductase, and catalase. However, superoxide dismutase significantly decreased (13%, P=0.018) after consumption of the low PUFA diet. Total cholesterol increased by 13% (P=0.014) after consumption of the low PUFA diet. CONCLUSIONS: This study indicates that although increasing dietary levels of PUFA may favourably alter cholesterol profiles, the same dietary changes may adversely affect some indices of lipid peroxidation. Care should be taken when providing dietary advice on PUFA intake and an adequate intake of antioxidants to match any increased PUFA may be important for preventing oxidative stress.     

A novel series of non-nucleoside inhibitors of inosine 5'-monophosphate dehydrogenase with immunosuppressive activity.

Inhibitors of inosine 5'-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205) are effective immunosuppressive drugs that may also have additional potential applications as antitumour and antimicrobial agents. The clinical value of the most potent and specific inhibitor of IMPDH, mycophenolic acid, is limited by its rapid metabolism in vivo to an inactive glucuronide derivative. There is, therefore, a considerable incentive to develop structurally novel, preferably non-nucleoside, inhibitors with greater metabolic stability than mycophenolic acid. Here, we describe a high throughput screen for inhibitors of IMPDH, which facilitated the discovery of a single novel non-nucleoside inhibitor from a collection of approximately 80,000 compounds. The inhibitor is a pyridazine, which, like mycophenolic acid, exerts uncompetitive inhibition of IMPDH. Analysis of the enzyme kinetics suggests that the inhibitory action of the pyridazine is similar to that of mycophenolic acid, which involves trapping of a covalent intermediate formed during the conversion of IMP to xanthosine monophosphate. Chemical modification of the lead compound resulted in pyridazine derivatives with enhanced potency against IMPDH and guanine nucleotide synthesis in cultured cells in vitro and also against guanine nucleotide synthesis in the mouse spleen in vivo. One of the compounds was available in sufficient quantity to demonstrate highly effective immunosuppressive activity in a model of delayed type hypersensitivity in mice. To our knowledge, the novel pyridazines described in this report represent the first non-nucleoside uncompetitive inhibitors of IMPDH with immunosuppressive activity since the discovery of the inhibitory activity of mycophenolic acid and its derivatives thirty years ago.     

Effect of a long-term low tryptophan diet on the prolactin responses to the 5-HT1A and 5-HT2C agonists, 8-OH-DPAT and mCPP in the male rat

The study was undertaken to assess the long term effects of tryptophan (TRP) depletion through diet on the prolactin (PRL) responses to the serotonin (5-hydroxytryptophan, 5-HT) agonists m-chlorophenyl-piperazine (mCPP) and 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) in the male rat. The low TRP diet caused significant reductions in both plasma total TRP and brain cortical 5-HT content together with a significant increase in the PRL responses to mCPP. In contrast the PRL responses to 8-OH-DPAT in animals on the low TRP diet for 1 week and 6 weeks were similar to control rats. However, a small but significant increase in PRL was observed at 2 min after dosing in the 1-week group. At the same time the 3H-8-OH-DPAT binding parameters, Kd and Bmax, were similar in both control and TRP depleted animals. The results confirm that long-term TRP depletion causes a deficiency of brain TRP and a subsequent reduction of brain 5-HT. This is associated with an enhanced PRL response to mCPP probably resulting from a functional up-regulation of post-synaptic 5-HT2C receptors. The small or transient changes brought about by long-term TRP depletion on post-synaptic 5-HT1A receptors, suggests that these receptors may be less susceptible to 5-HT depleting effects than the 5-HT2C subtype.