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W H Thompson

Publications and source records attributed to W H Thompson.

At least 19 recordsLinked to original sources
PubMed1995

Comparison of the M RNA genome segments of two human isolates of La Crosse virus.

The M genomic RNA segments of La Crosse (LAC) virus isolates from the brains of two children autopsied 18 years apart in Wisconsin were molecularly cloned using a reverse transcriptase-PCR assay and the nucleotide sequences of the cDNAs determined. The M RNA of each virus contains 4526 nucleotides, similar to that reported previously for a New York mosquito isolate of LAC. There were 20 nucleotide differences between the two human isolates, which results in the prediction of 7 amino acid changes in the proteins encoded in the single, long open reading frame of the M segment. One of these predicted differences occurs in the G2 glycoprotein and six in the G1 glycoprotein. The two viruses were identical in terms of predicted amino acid sequence in the region believed to represent a nonstructural protein. These data have been further compared to those available for two other California serogroup isolates.

Amino Acid Sequence↗
PubMed1991

Ingrowth and formation of bone in defects in an uncemented fiber-metal total hip-replacement model in dogs.

An osseous defect was created in the acetabulum and femur of twenty dogs, and then a fiber-metal total hip prosthesis was inserted. A comparison was made between the effects of leaving the defects unfilled, filling the defects with an autogenous bone graft, and filling them with a 50:50 mixture of autogenous bone graft and a biphasic ceramic composed of hydroxyapatite and tricalcium phosphate. The characteristics of formation of bone within the sites of the defects and the extent of the ingrowth of bone into the underlying porous surface were analyzed. At six and twelve weeks after implantation, the dogs in the control group (unfilled defects) had the least amount of bone in the sites of the defects. In the dogs that had had an autogenous bone graft and those in which the defects had been filled with a mixture of autogenous bone graft and biphasic ceramic, there were excellent osteoconductive properties in the filling of the sites of the defects with new bone. A comparison was made between the amount of bone that formed in the osseous defects and the amount that formed in the spaces of the porous-surfaced fiber-metal components of the prostheses, directly underlying and adjacent to the defects. At six weeks, the greatest amount of ingrowth of bone into the spaces of the underlying titanium fiber-metal acetabular components was seen in the control group (22 per cent of the porous surface), followed by the group in which the defects had been filled with a mixture of autogenous bone graft and biphasic ceramic (19 per cent). The defects that had been filled only with autogenous bone graft had poor ingrowth of bone into the porous surface (4 per cent) and predominantly fibrous ingrowth. At twelve weeks, these defects again showed the least amount of ingrowth of bone (15 per cent) compared with the defects in the control group (24 per cent) and those that had been filled with a mixture of autogenous bone graft and biphasic ceramic (24 per cent). No statistically significant differences were found in the amount of ingrowth of bone into the defects that had been created in the femur in the three groups of dogs at either six or twelve weeks. However, the trends appeared to correlate with the data for the acetabular defects.

Acetabulum↗
PubMed1983

Quantitation of La Crosse virus in venereally infected Aedes triseriatus.

The replication of two strains of La Crosse (LAC) virus, prototype and an unpassaged field isolate, was followed in intrathoracically inoculated male and venereally infected female Aedes triseriatus mosquitoes. The venereal infection rate following induced mating was 13.6% of 44 females inseminated by males inoculated with prototype virus, and 26.3% of 38 females inseminated by males inoculated with an unpassaged field strain. The males consistently contained concentrations of virus in reproductive tracts equal to or greater than those in salivary glands (SG). In contrast, venereally infected females generally contained the highest concentrations of virus in SG. Prototype LAC virus was demonstrable in nearly all organs of the infected females by 10 days following mating; the unpassaged field strain was detectable in all organ systems tested by day 6. There appeared to be no significant differences in replication between the prototype and field isolate viruses.

Aedes↗
PubMed1983

Lower rates of oral transmission of La Crosse virus by Aedes triseriatus venereally exposed after engorgement on immune chipmunks.

Transmission rates of La Crosse (LAC) virus observed in Aedes triseriatus females that had engorged on chipmunks with antibody to LAC and had been mated by infected males 5-11 days later (24%, 69/288) were 40% lower than in those fed on chipmunks without antibody (38%, 112/293). Similar results were obtained in three separate trials using males infected 1) by inoculation with prototype LAC virus, 2) transovarially with a field strain, or 3) transovarially with the field strain following passage through a viremic chipmunk. Similar rates were also observed in trials with F2 and F3 progeny of several strains of Ae. triseriatus collected from LAC-endemic and non-endemic areas. Reduction of oral transmission by venereally infected females mated by transovarially infected males following engorgement of antibody in chipmunks or other vertebrates could be important in the natural control of LAC virus, since most adult chipmunks sampled in endemic areas have antibodies neutralizing LAC. Ten-fold higher rates of venereal infection found in females mated by infected males 5 or more days after engorgement on LAC antibody-negative chipmunks than in those mated without prior engorgement extend previous findings of higher rates of transmission after engorgement on laboratory mice to include the natural vertebrate host.

Aedes↗
PubMed1983

La Crosse encephalitis: occurrence of disease and control in a suburban area.

Fifteen (6.4%) of 233 residents sampled in State Road Coulee (SRC) during 1972-73 had antibodies neutralizing La Crosse (LAC) virus, 9 (3.9%) trivittatus (TVT), 12 (5.2%) Jamestown Canyon (JC) and 2 (0.9%) Bunyamwera serogroup virus. Six of seven youths who had antibodies to LAC virus had been ill: three were serologically confirmed as cases of LAC encephalitis and three had possibly related illnesses. The other reported no illness. Possibly related illnesses were reported by 1 of 10 adults with antibody to LAC; also by 3 of 6 youths who had antibodies to TVT or JC viruses, and by 4 of 39 youths who did not have these antibodies. In prospective studies, 4 of 132 sampled again during 1977 had acquired antibodies, including 2 to LAC and 2 to JC virus. The LAC disease-infection rate was 50%. One of those with antibody to LAC virus was a girl with encephalitis who had a serologically confirmed infection a year after she had moved away from SRC. Her exposure to mosquitoes was not in SRC. The other was a boy who remained a resident but did not have encephalitis or other severe illness. The two who had acquired antibody to JC virus were boys who reported histories of undiagnosed febrile illnesses while attending summer camps in central Wisconsin. Control measures, including closure of treeholes, removing old tires and education, were applied. LAC infections in SRC were reduced from six during 1965 thru 1972, to only one during 1973 thru 1977. No cases have been found in SRC since 1977. Following expansion to a county-wide control program, LAC encephalitis in La Crosse County has been reduced from seven and eight cases during 1978 and 1979 to only one and two during 1980 and 1981. No cases have been found in La Crosse County so far during 1982.

Adolescent↗
PubMed1982

Vascular spindle cell lipoma.

Spindle cell lipoma is a neoplasm of adipose tissue that primarily affects posterior necks and shoulders of men in their fifth to seventh decades. It consists of a mixture of adipose tissue and spindle-shaped cells that could be misinterpreted as sarcoma. A clinical and pathological study of two patients, both men, with vascular variants of spindle cell lipoma is presented. These tumors were unusual clinically, in that one caused pain on motion and the other was painful to palpation. On microscopic examination, their vascularity was augmented over previously described examples of spindle cell lipoma.

Adult↗
PubMed1982

Indirect fluorescent-antibody technique for serological diagnosis of La Crosse (California) virus infections.

A clinically relevant indirect fluorescent-antibody technique (IFA) was developed for the serological diagnosis of La Crosse virus infections. The IFA (67%) was as sensitive as the hemagglutination inhibition (58%) and neutralization (58%) tests in the detection of antibodies in acute-phase specimens. Immunoglobulin M antibodies were detected by the IFA test in 48% (11 of 23) of these specimens. Diagnostically significant increases in IFA titer were detected in 86% (19 of 22) of the paired samples. Antibodies were detectable in some patients 7 years after infection; however, the IFA test was not as sensitive as the other two tests in the detection of previous infections.

Child↗
PubMed1981

Genotypic varieties of La Crosse virus isolated from different geographic regions of the continental United States and evidence for a naturally occurring intertypic recombinant La Crosse virus.

The tripartite ribonucleic acid (RNA) genomes of 23 alternate isolates of La Crosse virus have been analyzed by the procedure of oligonucleotide fingerprinting. By comparison with the fingerprints of the three viral RNA species (large, medium and small) of prototype La Crosse virus, the viruses have been categorized in terms of the degree of their RNA sequence relatedness. The A type La Crosse viruses, which have been recovered from Wisconsin, Minnesota, Indiana and Ohio, have viral RNA sequences that are closely related to those of prototype La Crosse virus. The B type La Crosse viruses, which have been recovered from Minnesota, Wisconsin and Illinois, have RNA sequences which, although related, are easily distinguished from those of type A viruses. A La Crosse virus isolate obtained from Rochester, Minnesota, appears to be an intertypic type A/B recombinant, it has a small size RNA segment like those of the B type La Crosse virus isolates, but medium- and large-sized RNA species like those of the A type La Crosse virus isolates. The C type La Crosse viruses have viral RNA sequences that neither closely resemble the A or B type La Crosse viruses. They have been recovered from eastern Ohio, New York State, Texas, Georgia and North Carolina.

Bunyaviridae↗
PubMed1980

Effect of deflector shields fitted in the milking machine teatcup liner on bovine udder disease.

Deflector shields were inserted in the teatcup to prevent 'impacts' against the teat end, and their effect on the rate of new udder infections was studied on 15 commercial dairy farms in Britain and 16 in Australia. Small metal shields were fitted between the liner barrel and short milk tube of 2 teatcups in each cluster in a milking installation so that all cows in a herd always had the same 2 quarters shielded. Half-udder comparisons were made using 1039 cows in the British herds and 1268 in the Australian herds. Herds were quarter-sampled for cytological and bacteriological examination when shields were fitted at the start of the experiment and again after 6 months. The shield effects were similar in the 2 experiments. The combined results from the 31 farms showed that 10.5% fewer quarters became infected when protected by shields (P less than 0.05). In the 1287 cows that had no infected quarters at the start of the trial, 15% fewer quarters became infected when protected by shields (P less than 0.01). The shield effect was mainly confined to hind quarters in which 23% fewer shielded quarters became infected (P less than 0.001). The small reduction of 2% in forequarters was not significant. In the 16 herds in which post-milking disinfection of teats was practised, shielded quarters had 23.5% fewer new infections than unshielded quarters (P less than 0.01). In 6 British herds milked in installations classed as non-standard, shielded quarters had almost 50% fewer new infections than the unshielded quarters (0.05 less than P less than 0.10). The results provide evidence of a milking machine effect, at varying levels of intensity, to increase new infection rates on all or most farms. Control of this machine effect could lead to substantial reduction in new infections in some herds and a modest reduction in most.

Animals↗
PubMed1979

A comparison of La Crosse virus isolated obtained from different ecological niches and an analysis of the structural components of California encephalitis serogroup viruses and other bunyaviruses.

Analyses of the oligonucleotide fingerprints of the three genome ribonucleic acid (RNA) species of 11 isolates of La Crosse (LAC) virus, obtained from various ecological niches in the northern United States and compared to those of prototype LAC virus, showed that in each place from which these isolates were obtained LAC variants and varieties were present with related, but distinguishable, nucleotide sequences for their large, medium, or small RNA species. The RNA genomes of prototypes trivittatus (TVT), snowshoe hare (SSH), Tahyna (TAH), and Lumbo (a variety of TAH) viruses of the California encephalitis (CE) serogroup, and Guaroa of the Bunyamwera serogroup also consist of three RNA species, each with unique and distinguishable nucleotide sequences which bear little resemblance to those of the LAC virus isolates. The virions of CE group viruses (CE, Jamestown Canyon, Keystone, LAC, Melao, SSH, TVT, TAH viruses and South River, an unregistered virus) have three major viral polypeptides, designated G1, G2, and N.

Arboviruses↗
PubMed1979

Higher venereal infection and transmission rates with La Crosse virus in Aedes triseriatus engorged before mating.

Infection of colonized female Aedes triseriatus by La Crosse (LAC) virus occurred more frequently when females were inseminated by infected males after the females engorged blood (49% of 39) than when mating took place before engorgement (4% of 554). Salivary transmission of LAC virus to mice also was more frequent in females venerally infected after engorgement on a normal mouse (35% of 34) than in females mated before engorgement (2% of 49). LAC virus was transovarially transmitted by 40% of 10 females mated by infected males, and in 64% of 279 progeny reared from eggs of second or later ovarian cycles.

Aedes↗
PubMed1978

Diagnosis of California La Crosse virus infection by counterimmunoelectrophoresis.

La Crosse virus cell culture-derived soluble antigen was used in a counterimmunoelectrophoresis procedure to assess the presence or absence of La Crosse antibodies in 79 paired acute- and convalescent-phase human sera. The counterimmunoelectrophoresis test appeared to measure the same antibody as the complement fixation test but was more sensitive and rapid.

Antibodies, Viral↗
PubMed1978

Venereal transmission of La Crosse virus from male to female Aedes triseriatus.

Horizontal transmission of La Crosse (LAC) arbovirus in colonized Aedes triseriatus was first observed in mating cages. LAC antigen was visualized by fluorescent antibody technique in multiple organs of 5 (2.5% of 198 females dissected after contact in mating cages with males, with a transovarial infection rate of 31%. Venereal transmission of LAC virus was demonstrated by limited contact induced mating. Antigen was detected in bursal contents of 35 (53%) of 66 females dissected within 24 h after induced mating by males previously infected by intrathoracic inoculation. Antigen was observed in ovaries, heart, gut, salivary glands, or other organs in 13 (3.4%) of 379 females dissected 1 to 14 days post-mating. LAC virus was isolated from infected males, from contents of the bursa copulatrix of females following mating, and from dissection remnants of 6 of the 13 females in which disseminated antigen had been observed. Venereally infected females were shown to be capable of transmission of LAC virus by bite to mice and to eggs.

Aedes↗
PubMed1977

Venereal transmission of La Crosse (California encephalitis) arbovirus in Aedes triseriatus mosquitoes.

Veneral transmission of La Crosse virus by males of Aedes triseriatus was demonstrated. La Crosse virus was detected in the bursa of females after induced copulation, and disseminated infection was shown to occur occasionally. Since males of Aedes triseriatus have transovarial filial infection rates similar to those of females and can repeatedly mate, veneral transmission may be an important supplement to other natural endemic maintenance mechanisms.

Aedes↗
PubMed1976

Delineation of La Crosse virus in developmental stages of transovarially infected Aedes triseriatus.

The tropisms and development of La Crosse (LAC) virus in stages of transovarially infected Aedes triseriatus were studied with fluorescent antibody (FA) stained dissected organs and titrations of individual arthropods in suckling mice. Viral antigen was detected by FA in 95 of 387 dissected larvae, pupae, and adults. In larvae highest levels of fluorescence were detected in the alimentary tract, followed by ganglia, malpighian tubule, muscle, and other tissues. No specific organs or germ layer-derived tissues appeared to be the sole source of viral replication. Most tissues and organs of A. triseriatus are capable of maintaining LAC virus. Antigen was detected in the identifiable organs immediately upon emergence from the egg. In pupae and adults antigen was detected at high levels in foregut, gonadal and associated tissues, and in salivary glands, which would indicate females could be infective upon emergence. Virus was isolated from all arthropod stages, in 32 of 130 individuals inoculated into suckling mice. Titrations ranged from less than 1.0 log10 SMICLD50 per 0.02 ml for eggs and 1st instar larvae to 3.0 log10 SMICLD50 for 4th instar larvae. Adults and pupae averaged between 2.0 and 3.0 log10 SMICLD50. Increases in titer during maturation were mainly related to increases in size of the organism rather than in titer per unit volume.

Aedes↗