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Biomedical subjects

W H Bancroft

Publications and source records attributed to W H Bancroft.

At least 55 records · Page 3Linked to original sources
PubMed1979

Kinetocardiography: past and present.

Kinetocardiography (KCG) records the absolute displacement of several points of the precordium. KCG utilizes only the low frequency motions (0--30 Hz). Computer availability allows for many improved methods of KCG evaluation. Amplitude and time normalization make averaging of curves more meaningful. Determining the mean of many KCGs of patients with the same disease offers a useful means of comparison. Of more recent interest is the possibility of comparing preoperative to postoperative curves of patients undergoing coronary artery surgery. Greatly increased total systolic retraction is evidenced in patients with improved clinical findings.

Computers↗
PubMed1977

The use of the systolic time interval for predicting left ventricular ejection fraction ischemic heart disease.

A large series of 306 patients with ischemic heart disease was studied with automated systolic time intervals and left ventricular ejection fraction as determined by the angiocardiographic method. It was found the pre-ejection period, left ventricular ejection time, delta values, and PEP/LVET ratio all were related to the ejection fraction. However, in all instances the correlation was too low and the scatter of the data was too large to warrant the use of the systolic time intervals for predicting left ventricular function as indicated by the ejection fraction.

Coronary Disease↗
PubMed1977

Transmission of hepatitis B virus to gibbons by exposure to human saliva containing hepatitis B surface antigen.

A pool of whole-mouth saliva collected from five human carriers of hepatitis B surface antigen, subtype adr, was found to contain antigen particles with mean diameters of 23.3 and 41.8 nm as seen by immune electron microscopy. Two gibbons received subcutaneous injections of the pooled saliva and developed serological and, in at least one animal, biochemical evidence of hepatitis B virus infection at 12 and 22 weeks, respectively. Although none of eight other gibbons that were exposed by the nasal or oral routes were infected, the experiment demonstrated that human saliva can serve as a vehicle for the transmission of hepatitis B virus.

Adult↗
PubMed1976

Hepatitis B antigen and antibody in the U.S. Army: prevalence in health care personnel.

The prevalence of Hepatitis B surface antigen (HB(S)Ag) and antibody (anti-HB(S)) seropositivity and the association of seropositivity with demographic, personal health, and professional experiences were studied in a cohort of Army Medical Department officer personnel. Serologic evidence of Hepatitis B infection was found in 5.0 per cent of personnel and was associated with age, sex, place of birth, history of hepatitis, history of blood transfusion, and previous overseas assignments. Seropositivity rates were higher for patient care oriented officer personnel, especially for those in surgical specialties, and rose with increasing professional experience. These data present a composite of risk factors operative in the acquisition of Hepatitis B seropositivity and identify a cohort for prospective study.

Adult↗
PubMed1976

Isolation of Langat virus from Haemaphysalis papuana Thorell in Thailand.

A strain of Langat virus (LGT), T-1674, was isolated from a pool of Haemaphysalis papuana Thorell collected in the forest of Khao Yai National Park in Central Thailand. The isolated virus was found to have growth and antigenic similarity to the prototype Langat strain (TP-21). This is the first report of a natural infection of Haemaphysalis ticks with LGT and of the isolation of this arbovirus in Thailand. The wide distribution of known vectors of LGT in Thailand suggests that the virus may be present in other areas of the country.

Animals↗
PubMed1976

Epidemic influenza in a hill tribe of northwest Thailand.

An investigation of an epidemic of respiratory disease in a remote region of northwest Thailand revealed Influenza A/H3N2 as the etiologic agent. This epidemic would not have been recognized were it not for an unusual increase in respiratory disease following a meeting attended by residents of many villages. The influenza strains isolated most closely resembled A/Port Chalmers/1/73 when tested by hemagglutination inhibition but showed consistent antigenic differences when tested by quantitative neutralization. It is suggested that the differences noted between this strain and influenza viruses isolated elsewhere may have been due to the sequential transmission of influenza through partially immune people.

Child↗
PubMed1976

Shock syndrome in primary dengue infections.

During 1974, 114 patients with dengue hemorrhagic fever were studied at the Bankok Children's Hospital. Over 40% of the patients had dengue shock syndrome. Five fatal cases were included in the study. Primary dengue infections were identified by absent or low titered antibodies in acute sera and the sequential development of IgM antibodies followed by IgG antibodies during convalescence. Three patients, aged 4,8, and 12 years, had primary dengue infections with shock. Although no convalescent sera could be tested two other patients, aged 7 to 12 years, with fatal disease also appeared to have primary infections. At the time of shock patients with primary infections had subnormal concentrations of complement factor 3. The data show that in older children dengue shock syndrome associated with complement depression can occur during primary as well as secondary infections.

Antibodies, Viral↗
PubMed1975

Subtypes of hepatitis B surface antigen in Southeast Asia.

The prevalences of hepatitis B surface antigen (HBs Ag) subtypes in Thais, Cambodians, and Vietnamese were compared with the prevalences in Americans residing in Southeast Asia. HBs Ag was found with approximately equal frequency in Thai (43 percent) and American (39 percent) patients with hepatitis. However, higher prevalences of HBs Ag were found in asympotomatic Thais (9.5 percent), Cambodians (11.9 percent), and Vietnamese (14.3 percent) than in asymptomatic Americans (0.7 percent). Among asymptomatic Thais, the ratio of HBs Ag/adr to HBs Ag/adw was approximately 10:1, with one exception: adw was not detected in a rural population of northern Thailand. The y determinant was not found in Thais. In contrast, both d and y determinants were found in Americans. These observations conform to a geographic pattern, with ad as the predominant combination in the Far East. In Southeast Asia determinants w and r are more useful epidemiologic markers than y and d.

Animals↗
PubMed1975

Hepatitis B antigen in saliva, urine, and stool.

A survey of hepatitis B patients, asymptomatic hepatitis B antigen (HBsAg) carriers, and control subjects was conducted to determine the relationship between antigenemia and antigen excretion in saliva, urine, and stool. Radioimmunoassay was used to detect HBsAg. Specificity-confirmed HBsAg was detected in the saliva of 6 (30%) of 20 antigenemic patients, 1 (5%) of 20 nonantigenemic patients, 14 (34%) of 41 carriers, and 0 of 112 controls. HBsAg was detected in urine only after 100-fold concentration of first-morning specimens. Specificity-confirmed HBsAg was present in the urine of 7 (16%) of 43 carriers; unconfirmed HBsAg was found in the urine of 5 (13%) of 38 patients and 5 (5%) of 112 controls. Unconfirmed HBsAg was detected in concentrated stool specimens from 5 (46%) of 11 patients and 3 of 8 carriers and controls. Longitudinally collected specimens from antigenemic subjects showed no consistent patterns of antigen excretion.

Carrier State↗
PubMed1974

Specificity and sensitivity of radioimmunoassay for hepatitis B antigen.

Sera from a survey of 6,026 people were tested for hepatitis B surface antigen by using radioimmunoassay and counterelectrophoresis. Forty-eight sera (0.79%) were positive by counterelectrophoresis and 152 sera (2.52%) were positive by radioimmunoassay, using the most liberal of the recommended criteria for positivity (i.e., counts 3 standard deviations above the mean). Absorption tests performed on the 152 radioimmunoassay-positive sera showed that 10 (6.6%) were false-positive reactions to guinea pig protein, 74 (48.6%) were due to false-positive reaction(s) with other protein(s) in the test system, and 68 (44.8%) were true positives. There was a strong correlation between the degree of elevation of radioactive counts and the proportions of sera that were true positives; all 49 sera with counts >50 standard deviation units above the mean were true positives, but only 19 (18.4%) of the 103 sera with counts <50 standard deviation units were true positives. A few sera with high counts required absorption with type-specific (type D) antisera. The following conclusions were reached from this study: (i) absorption tests should be run on all radioimmunoassay-positive, counterelectrophoresis-negative sera; (ii) most (about 90%) false positives are not due to anti-guinea-pig protein reactions; and (iii) radioimmunoassay, in combination with absorption tests, yields a modest increase (about 35%) in detection of true positives over use of counterelectrophoresis alone.

Animals↗