Biomedical subjects

E L Hall

Publications and source records attributed to E L Hall.

14 recordsLinked to original sources

PubMed2001

Invasive group B streptococcal disease in Maryland nursing home residents.

Between 1991 and 1995, among 999 nonpregnant adult Maryland residents with group B Streptococcus (GBS) isolated from a normally sterile site, 84 resided in nursing homes (NHs). The age-adjusted annual incidence of GBS infection (per 100,000 population) among those > or = 65 years old was 72.3 for NH residents and 17.5 for community residents (relative risk, 4.1; P < 0.001). Thirty-four case patients resided in 11 NHs with > or = 2 cases; 1 NH had 8 case patients within 22 months. Six of 8 case patients from 3 NHs had serotype V GBS. Molecular subtyping of several isolates identified 2 case patients in 1 NH with identical subtype patterns. NH residents have a markedly higher incidence of invasive GBS than do community residents > or = 65 years old and may serve as a target group for immunization when GBS vaccines become available. Further evaluation of intra-NH transmission of GBS is warranted.

Aged↗

PubMed2001

Role of surgical intervention in the management of crotaline snake envenomation.

Crotaline venoms produce various toxic effects. Although these are most commonly treated with specific antivenoms, surgical management of snakebite has also been practiced for many years. Surgical approaches to pit viper envenomation include incision or excision of the bite site, fasciotomy, and digit dermotomy. The evidence regarding each of these procedures is sparse; however, incision or excision of the bite site are difficult to advocate. Fasciotomy and digit dermotomy may be appropriate in carefully selected patients.

Animals↗

PubMed1999

Studies on the measurement of phospholipase A2 (PLA2) and PLA2 inhibitor activities in ram semen.

Extraction with Tris-citrate or Tris-NaCl-EGTA improved the yield of phospholipase A2 (PLA2) from ram semen by 40-50 fold over the previously recommended method of extraction by dilute (0.18 N) sulphuric acid. The enzyme activity in the citrate extract deteriorated more rapidly than in Tris-NaCl-EGTA. The semen PLA2 activity was optimum at pH 8.0, heat sensitive at 70 degrees C for 30 min, activated by Ca2+ (although approximately 60% activity was also found in the absence of calcium) and did not exist as a pro-enzyme. The semen PLA2 activity was equally distributed among the sperm and seminal plasma (SP) components of ram semen. However, the low levels of PLA2 activity in the SP of vasectomised rams tend to suggest that PLA2 in the SP fraction may have originated from testicular or epididymal secretions or leakage, from sperm. PLA, in sperm exists as a large molecular weight aggregate, whereas in SP it is present as a smaller aggregate. In addition to PLA2, semen also contained PLA2 inhibitor activities. Inhibition was observed against PLA2s from bee venom, pig pancreas and oviductal extracts. The inhibitory activity is presumed to be due to a large molecular weight protein as the inhibitor activity was not extracted in a chloroform:methanol (2:1; v/v) mixture, it was non-dialysable, precipitated by 10% trichloroacetic acid and destroyed by proteases. The inhibitor activity was distributed in various molecular weight fractions of sperm, SP and SP from vasectomised rams.

Animals↗

PubMed1998

Effect of oral creatine ingestion on parameters of the work rate-time relationship and time to exhaustion in high-intensity cycling.

The relationship between work rate (W) and time to exhaustion (t) during intense exercise is commonly described by either a hyperbolic function (NLin), t= W'/(W-Wcp), or by its linear equivalent (LinW) Wlim=W' + Wcp(t). The parameter Wcp (critical power) has been described as an inherent characteristic of the aerobic energy system, while W' has been shown to be a ralid estimate of anaerobic work capacity. Recent studies have demonstrated that oral supplementation of creatine monohydrate (CrH2O) increases total muscle creatine stores, and have linked these increases to improved performances in intense intermittent exercise. This study was conducted to determine the effect of CrH2O supplementation on estimates of W' and Wcp derived from the NLin and LinW equations, and to determine the effect of CrH2O on t in exhaustive constant power exercise of different intensities. Fifteen active but untrained university students completed three phases of testing on a cycle ergometer: (1) familiarization, three learning trials, (2) baseline determination of W' and Wcp, four bouts performed at a W selected to elicit fatigue in 90-600 s, and (3) experimental determination of W' and Wcp, four bouts performed at the same W as baseline, but performed after 5 days of ingesting either a placebo (4 x 6 g of glucose/day) or CrH2O (4 x 5 g of CrH2O and 1 g glucose/day). Testing was administered in a double-blind manner. Analyses of covariance revealed a significant effect for CrH2O on both estimates of W' (NLin, P=0.04; LinW, P < 0.01), but not on estimates of Wcp (NLin, P=0.37; LinW; P=0.30). Within groups, t was significantly different for only CrH2O at the two highest Ws (P=0.04). It is concluded that oral ingestion of CrH2O increases estimates of W' due to an improved t at the shorter, more intense exercise bouts.

Administration, Oral↗

PubMed1997

Canebrake rattlesnake envenomation.

STUDY OBJECTIVE: To document the clinical presentation and course of consecutive cases of envenomation by the canebrake rattlesnake (Crotalus horridus atricaudatus). METHODS: The medical care provided all patients envenomated by canebrake rattlesnakes in two institutions was retrospectively reviewed. Particular attention was paid to coagulation abnormalities, serum enzymes, electrocardiographic findings, and treatment with antivenom. RESULTS: Of the 15 patients, envenomation was judged to be mild in 3, moderate in 6, and severe in 5. In one case envenomation caused death. The clinical course generally predicted the degree of increase in the serum creatinine kinase (CK) level, as well as the amount of antivenom used for treatment. Despite increases in serum CK concentration and frequent increases in the serum CK-MB fraction, we found no evidence of cardiac damage. CONCLUSION: In envenomation by North American pit vipers, rhabdomyolysis appears to be characteristic of envenomation by the canebrake rattlesnake. We speculate that toxins in the canebrake venom cause skeletal muscle rhabdomyolysis. Physicians caring for victims of canebrake bite should regard marked increases in CK concentration as coming from skeletal, not cardiac, muscle. Good general medical support and antivenom for victims with moderate to severe envenomation appears effective.

Adolescent↗

PubMed1992