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Biomedical subjects

J E Maynard

Publications and source records attributed to J E Maynard.

At least 127 records · Page 7Linked to original sources
PubMed1977

Simultaneous infection with type A and B hepatitis viruses.

The occurrence of a common source hepatitis A epidemic among the residents of a New England state mental institution where hepatitis B is hyperendemic provided an opportunity to observe concurrent infections with both agents. Nine HBsAg-positive individuals developed hepatitis A infections documented by hepatitis A antibody seroconversion in eight. The incidence of hepatitis A infections in susceptible HBsAg-positive persons (67%) did not differ from that in HBsAg-negative individuals (63%). The icteric to anicteric infection ratio in the HBsAG-positives (1:1.7) was similar to that in the negatives (1:2.1), and the clinical course in the antigen positives did not differ significantly from that of the antigen negatives. In addition to confirming previous reports that the viruses of hepatitis A and B are immunologically distinct, these results document that infection with either is independent of the other, and that the morbidity from simultaneous infection is no greater than that caused by either alone.

Adolescent↗
PubMed1977

Foodborne hepatitis A infection: a report of two urban restaurant-associated outbreaks.

The cities of Portland, Oregon, and Buffalo, New York, each experienced a restaurant-associated foodborne outbreak of viral hepatitis type A during 1975. Although there were several food handlers ill with viral hepatitis A in each of the restaurants involved, each outbreak was the apparent result of food contamination by a single food handler. In the Buffalo outbreak, food contamination was documented to have occurred for a brief period of time six days prior to onset of any symptoms in the index case. These outbreaks point out the uncommon occurrence of food contamination by individuals ill with type A viral hepatitis, the usefulness of two types of food questionnaires in identifying the vehicle(s) of transmission, and the apparent lack of benefit of widespread immune serum globulin administration as a control measure in this setting.

Adult↗
PubMed1977

Tick-borne relapsing fever: an interstate outbreak originating at Grand Canyon National Park.

During the 1973 summer season, 27 employees and 35 overnight guests at the North Rim, Grand Canyon National Park, Arizona, acquired febrile illnesses compatibel with relapsing fever. Sixteen cases were confirmed by finding Borrelia spirochetes in peripheral blood smears or inoculated Swiss mice. Retrospective surveys of 278 employees and 7247 guests at the park revealed that acquisition of illness was significantly associated with the persons sleeping in rustic log cabins and acquiring bites of "unknown" insects. From rodent nesting materials found in the walls and attics of cabins where cases had occurred, infective Ornithodoros hermsi ticks were recovered. Exceptional activity of ticks in human populations appeared to have resulted from a decreased population of the ticks' usual rodent hosts. Vector control activities consisted of spraying the cabins with residual insecticide, removing nesting materials, and "rodent proofing." This outbreak, the largest yet identified in North America, extends the known range of a principal vector and establishes the North Rim as an endemic source of tick-borne relapsing fever.

Adult↗
PubMed1977

Serodiagnosis of viral hepatitis A: detection of acute-phase immunoglobulin M anti-hepatitis A virus by radioimmunoassay.

A modified micro solid-phase radioimmunoassay (RIA) for antibody to hepatitis A virus (anti-HAV) was developed. This double antibody procedure was performed by coating the surface of a polyvinyl microtiter plate "well" with 200 microliter of a 1:1,000 dilution of a patient's test serum. Purified HAV and 125I-labeled immunoglobulin G (IgG) anti-HAV were then sequentially added to form an antibody sandwich. The specificity and sensitivity of the RIA procedure for anti-HAV were verified by examination of coded human and chimpanzee serum specimens. Radioimmunoassay of early-acute-phase serum specimens from human cases of hepatitis A revealed the presence of anti-HAV activity. Differential examination by RIA of IgG and IgM fractions of acute-phase sera from experimentally infected chimpanzees demonstrated that IgM contained the bulk of the anti-HAV activity. A modification of the RIA procedure for anti-HAV (RIA-IgM blocking), incorporating an incubation step with anti-IgM (Mu chain specific), was further shown to differentiate acute- from convalescent-phase hepatitis A sera. This adapted RIA-IgM blocking procedure required less than 1 microliter of a single acute-phase serum specimen for the diagnosis of viral hepatitis A.

Acute Disease↗
PubMed1977

Purification of hepatitis A virus from chimpanzee stools.

Hepatitis A virus antigen was purified from early acute-phase chimpanzee stools by a rapid three-step procedure using 7% polyethylene glycol precipitation, CsCl banding, and Sepharose 2B column chromatography. Electron microscopic examination of the hepatitis A virus entigen preparation revealed highly purified hepatitis A virus particles.

Animals↗
PubMed1976

Behaviour of e antigen and antibody during chronic active liver disease. Relation to HB antigen-antibody system and prognosis.

Serial determinations of e antigen and e antibody were made in 20 patients with chronic active liver disease and hepatitis-B surface antigen (HBsAg) or antibody (anti-HBs). The presence of e antigen was associated with failure to clear HBsAg, produce anti-HBs, or respond to treatment with steroids. It is proposed that the presence of the e antigen is associated with impaired host immune responses to hepatitis-B virus infection and a poor prognosis.

Adolescent↗
PubMed1976

Relation of e antigen to hepatitis B virus infection in an area of hyperendemicity.

A study of the e determinant of hepatitis B surface antigen in an area of hepatitis B hyperendemicity revealed that the presence of e antigen or of antibody to e in the sera of individuals was specifically related to evidence of past or present infection with hepatitis B virus. Among asymptomatic long-term carriers of hepatitis B surface antigen, presence of the e antigen was associated with elevated levels of aspartate and alanine aminotransferases in serum; this observation suggested that the e antigen might be a marker for persisting hepatic dysfunction. Higher levels of DNA polymerase found in carriers of the surface antigen with e antigen suggested that these individuals might have a higher level of circulating Dane particles and thus, perhaps, a higher level of hepatitis B virus infectivity.

Adolescent↗
PubMed1976

An outbreak of type B hepatitis associated with transfusion of plasma protein fraction.

An outbreak of type B hepatitis followed transfusion with a single lot of plasma protein fraction (PPF) at a 1200-bed hospital in June and July 1973. Of 51 recipients of the product, 31 were available as a study population and 19 (61%) had an illness compatible with hepatitis. Epidemiologic and serologic investigations provided firm evidence that this material was the vehicle for transmission of disease to its recipients. Recipients of four other PPF lots from the same manufacturer were studied. Two of these lots were also associated with extremely high clinical hepatitis attack rates (45% and 55%). The other two lots, which had been prepared from donor plasma contributing to the composition of the initially-studied PPF lot, failed to produced clinical illness, although one of these lots was associated with a high prevalence of hepatitis B seropositivity in recipients. Thus, a broad spectrum of clinical and serologic responses was evident in PPF produced from similar donor plasma and pasteurized in the same bulk container. This study is the first to incriminate heat-treated PPF in transmission of type B hepatitis and suggests the need for further studies of the effect of pasteurization cycles on inactivation of hepatitis B virus.

Antibodies, Viral↗
PubMed1976

Antiviral effects of virazole in chronic hepatitis B surface antigen-seropositive chimpanzees.

Virazole (Ribavirin, ICN 1229), a broad-spectrum, antiviral chemotherapeutic agent was used to treat two adult chronically hepatitis B surface antigen (HB(s) Ag)-seropositive chimpanzees. No significant change in serum hepatitis B surface antigen was noted and no adverse reactions were observed. The role of viral replication in the chronic carrier state of hepatitis B is discussed.

Animals↗
PubMed1976

Hepatitis B surface antigen in saliva, impetiginous lesions, and the environment in two remote Alaskan villages.

A study was conducted in an area of hepatitis B hyperendemicity to determin whether contact with infective bodily secretions or contaminated environmental surfaces could be involved in the transmission of the hepatitis B virus. Hepatitis B surface antigen was detected in gingival swab, saliva, and impetiginous lesion exudate samples from children. Hepatitis B surface antigen also was found in swab samples of surfaces frequently touched or placed in the mouth. In the absence of classical exposure to infectious blood or blood products, these findings suggested that, in a crowded home environment, saliva and cutaneous exudates containing hepatitis B virus may play a role in the transmission of hepatitis B.

Alaska↗