Flow increases with an enlarging intravenous catheter.

STUDY OBJECTIVE: To determine the increase in flow of a hydratable enlarging intravenous (IV) catheter in anesthetized patients. DESIGN: A randomized, nonblinded study, with standard Teflon IV catheters used as controls. SETTING: Operating room at a university medical center. PATIENTS: Thiry adult patients receiving general anesthesia for lower extremity surgery. INTERVENTIONS: An IV catheter was placed in the upper extremity, and flow measurements were made by measuring the time for infusion of 250 ml of normal saline within 1 minute after placement and at 1 hour after placement. MEASUREMENTS AND MAIN RESULTS: The enlarging catheters had a statistically significant average flow increase of 26% after 1 hour indwelling time. The standard Teflon catheters had no statistically significant change in flow after 1 hour. The percentage increase in flow for the enlarging catheters was not as great as previously seen in vitro. CONCLUSIONS: Flow through enlarging IV catheters placed in anesthetized patients increases after 1 hour. The percentage increase in flow is not as great as previously seen in vitro and may be due to skin, vein, and subcutaneous tissues preventing complete expansion.     

A preliminary cost effectiveness analysis of an intervention to reduce homelessness among the mentally ill

The Critical Time Intervention Project is a three-year clinical trial which tests a time-limited, supportive intervention to reduce recurrent homelessness among mentally ill men moving from a shelter to the community. Along with a comparison of nights spent homeless and other outcomes, the evaluation of the Critical Time Intervention includes a comparison of the relative costs of the intervention, compared to usual treatment. Such cost effectiveness analyses are difficult to perform and are rarely applied to mental health treatments. This paper presents the general scheme of this analysis and discusses critical issues in the construction and measurement of cost variables. Preliminary results which have implications for the cost analysis are presented.     

The effects of baclofen and pertussis toxin on epileptiform activity induced in the hippocampal slice by magnesium depletion

Bathing hippocampal slices in artificial cerebrospinal fluid without magnesium elicits repetitive, long ictal-like discharges termed ictaform events. The ictaform events are separated by interictal periods that are initially silent with no interictal bursts. Interictal bursts appear in the later part of the interictal periods and intensify just before the next ictaform event. The GABAB agonist, baclofen, entirely suppressed interictal bursts during the interictal periods and produced a dose-dependent prolongation of the interictal period. Conversely, in slices pretreated with pertussis toxin to reduce the GABAB neurotransmission, interictal bursts were greatly increased, often occupying the entire interictal period, although the total duration of the interictal periods was not affected. Pertussis toxin pretreatment also lengthened the ictaform events. These opposing effects of baclofen and pertussis toxin suggest that GABAB neuro-transmission is important in regulating both the occurrence of interictal bursts in the interictal period, as well as the duration of ictaform events in the low magnesium model of epileptiform activity.     

Limbic system dysfunction as a factor in some schizophreniform psychoses: case report and overview

A case is presented of a young woman whose schizophreniform psychosis was unresponsive to neuroleptic treatment, but who subsequently responded well to Carbamazepine. Several converging lines of investigation, suggesting an underlying Limbic System dysfunction, are discussed. Background to the Limbic System concept is provided.     

Bioavailability of estradiol as a marker for breast cancer risk assessment

The search for a hormonal marker in breast cancer has centered on estrogens and their metabolites. However, direct measurements of total amounts of these steroids have shown no convincing or consistent differences between normal women and women with breast cancer. The purpose of this study was to measure the percentages of non-protein-bound estradiol (%NPBE) and of estradiol bound to albumin (%ABE) and the levels of sex hormone-binding globulin (SHBG) both in women with breast cancer and in those free of disease. Serum was collected and analyzed within 2 weeks, using an isodialysis method. The mean %NPBE and %ABE were significantly higher in 32 women with breast cancer (1.73 and 64.0%, respectively) than in 32 matched disease-free women (1.43 and 48.6%, respectively) (P less than 0.001). No significant difference was observed in the levels of plasma albumin when the above matched groups were compared. However, plasma levels of SHBG were significantly lower in the women with breast cancer than in either the control population or matched controls. In this finding we differ from previous studies which reported no significant differences in the mean plasma levels of SHBG. In our study, the increased %NPBE and %ABE in some patients with breast cancer may be related to a lower level of plasma SHBG; other factors, too, may affect the distribution of estradiol. Our results support the hypothesis than an increase in %NPBE and %ABE or both may indicate an increased risk of breast cancer.     

Medical complications of prematurity

The improved survival of extremely premature infants has generated intense interest in the quality of life of the survivors. This review focuses on the major long-term complications of prematurity (developmental disability, retinopathy of prematurity, chronic lung disease) and concludes with an overview of the broader spectrum of morbidity. Severe impairment (cerebral palsy, mental retardation, retrolental fibroplasia, severe chronic lung disease) fortunately occurs in a small proportion of survivors. However, the prevalence of the lesser morbidities (minimal cerebral dysfunction/learning disability, poor growth, postneonatal illnesses, rehospitalization) is less clearly defined. These problems all have an impact on families, and on medical and educational services.