Molecules to maps: tools for visualization and interaction in support of computational biology

The volume of data produced by genome projects, X-ray crystallography, NMR spectroscopy, and electron and confocal microscopy present the bioinformatics community with new challenges for analyzing, understanding, and exchanging this data. At the 1998 Pacific Symposium on Biocomputing, a track entitled 'Molecules to Maps: Tools for Visualization and Interaction in Computational Biology' provided tool developers and users with the opportunity to discuss advances in tools and techniques to assist scientists in evaluating, absorbing, navigating, and correlating this sea of information, through visualization and user interaction. In this paper we present these advances and discuss some of the challenges that remain to be solved.     

Efficacy of praziquantel (0.25 mg kg(-1)) on the cecal tapeworm (Anoplocephala perfoliata) in horses

Aspiration of inflorescence or grass heads (seed head of grasses) often presents with atypical signs and symptoms because grass heads have a tendency to rapidly migrate to the periphery of the lung. If this is not recognized, it can lead to delay in diagnosis and serious complications. Removal with rigid bronchoscopy maybe difficult, and surgery is often needed. We report a case of a seven-month-old child who had a delayed diagnosis of grass head aspiration and subsequently presented with a life threatening tension pneumothorax. This case highlights the importance of obtaining a detailed history in cases of foreign body aspiration and the need to include it in the differential diagnosis of unexplained respiratory symptoms, especially those of sudden onset in children.     

More than 10 years of unrecognized nosocomial transmission of legionnaires' disease among transplant patients

OBJECTIVE: To investigate a cluster of cases of legionnaires' disease among patients at a hospital. SETTING: A university hospital that is a regional transplant center. DESIGN: Retrospective review of microbiology and serology data from the hospital laboratories and prospective surveillance via the radiology department; a case-control study and environmental sampling within the hospital and from nearby cooling towers. RESULTS: Diagnosis of seven cases of legionnaires' disease in the first 9 months of 1996 led to recognition of a nosocomial outbreak that may have begun as early as 1979. Review of charts from 1987 through September 1996 identified 25 culture-confirmed cases of nosocomial or possibly nosocomial legionnaires' disease, including 18 in bone marrow and heart transplant patients. Twelve patients (48%) died. During the first 9 months of 1996, the attack rate was 6% among cardiac and bone marrow transplant patients. For cases that occurred before 1996, intubation was associated with increased risk for disease. High-dose corticosteroid medication was strongly associated with the risk for disease, but other immunosuppressive therapy or cancer chemotherapy was not. Several species and serogroups of Legionella were isolated from numerous sites in the hospital's potable water system. Six of seven available clinical isolates were identical and were indistinguishable from environmental isolates by pulsed-field gel electrophoresis. Initial infection control measures failed to interrupt nosocomial acquisition of infection. After extensive modifications to the water system, closely monitored repeated hyperchlorinations, and reduction of patient exposures to aerosols, transmission was interrupted. No cases have been identified since September 1996. CONCLUSIONS: Legionella can colonize hospital potable water systems for long periods of time, resulting in an ongoing risk for patients, especially those who are immunocompromised. In this hospital, nosocomial transmission possibly occurred for more than 17 years and was interrupted in 1996, after a sudden increase in incidence led to its recognition. Hospitals specializing in the care of immunocompromised patients (eg, transplant centers) should prioritize surveillance for cases of legionnaires' disease. Aggressive control measures can interrupt transmission of this disease successfully.     

Time of peak drug concentration after a single dose and a dose at steady state

The time of peak concentration after administration of oral drug is an often quoted and used pharmacokinetic parameter. It is not well appreciated, however, that the peak times after a single dose and a dose at steady state during a multiple administration regimen can differ significantly. This article derives the mathematical relationships that determine how a peak time at steady state differs from that after a single or first dose. These relationships are then evaluated using three different approaches: 1) graphic simulations of time courses of drug concentration for three hypothetical drugs; 2) comparisons of predicted and observed peak times using examples from the literature; and 3) comparisons of predicted and simulated peak times based on different sampling schedules for three hypothetical drugs. The key finding is that peak times after a dose at steady state can occur considerably earlier after administration than after a single dose. However, the manner by which peak times are usually determined, that is, the sampling time corresponding to the highest measured drug concentration, imposes significant limitations on the usefulness of this parameter.     

Portal hypertension changes following selective splenorenal shunt surgery. Evaluation by percutaneous transhepatic portal catheterization, venography, and cinefluorography

A series of ergot alkaloids, together with the DA agonists apomorphine and piribedil, were tested for protective effects against audiogenic seizures in an inbred strain of mice (DBA/2) and for induction of circling behaviour in mice with unilateral destruction of one nigrostriatal DA pathway. The order of potency against audiogenic seizures was apomorphine greater than ergocornine greater than bromocryptine greater than ergometrine greater than LSD greater than methysergide greater than piribedil while that observed in the rotating mouse model was apomorphine greater than ergometrine greater than ergocornine greater than bromocryptine greater than piribedil. LSD caused only weak circling behaviour even when administered in high doses (greater than 1 mg/kg). Methysergide was ineffective. Prior administration of the neuroleptic agent haloperidol blocked the effect of DA agonists and of ergot alkaloids in both animal models. The possible action of ergot alkaloids as DA agonists is discussed.