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Biomedical subjects

L Kuller

Publications and source records attributed to L Kuller.

At least 55 records · Page 3Linked to original sources

Epidemiology of the post-polio syndrome.

A late-onset syndrome, consisting of muscle weakness, muscle pain, and unaccustomed fatigue, has been reported with increasing frequency among former poliomyelitis patients. A population-based cohort of poliomyelitis patients from Allegheny County, Pennsylvania, was traced and surveyed to estimate the prevalence and incidence and to identify determinants of the post-polio syndrome. A questionnaire validated in clinical examinations of 40 cohort members was used in the survey. The prevalence of the post-polio syndrome was 28.5% of all paralytic cases (95% confidence interval 24.4-32.6). The risk of post-polio syndrome was significantly higher among patients who sustained substantial permanent impairment after polio and among females. The incidence did not vary with age at acute onset, acute severity, or level of physical activity after recovery. The strongest determinant of post-polio syndrome onset was the length of the interval following the acute illness, with incidence peaking at 30-34 years. Of all cases of post-polio syndrome, 79% reported no major change in impairment status since onset. This study demonstrates that poliomyelitis patients are not equally susceptible to post-polio syndrome within the interval of 30-40 years after the original illness. For syndrome cases, the onset was associated with new neuromuscular symptoms and functional changes but not with major new impairment.

Acute Disease↗

Protection of macaques against SIV infection by subunit vaccines of SIV envelope glycoprotein gp160.

Simian immunodeficiency virus (SIV) is a primate lentivirus related to human immunodeficiency viruses and is an etiologic agent for acquired immunodeficiency syndrome (AIDS)-like diseases in macaques. To date, only inactivated whole virus vaccines have been shown to protect macaques against SIV infection. Protective immunity was elicited by recombinant subunit vaccines. Four Macaca fascicularis were immunized with recombinant vaccinia virus expressing SIVmne gp160 and were boosted with gp160 produced in baculovirus-infected cells. All four animals were protected against an intravenous challenge of the homologous virus at one to nine animal-infectious doses. These results indicate that immunization with viral envelope antigens alone is sufficient to elicit protective immunity against a primate immunodeficiency virus. The combination immunization regimen, similar to one now being evaluated in humans as candidate human immunodeficiency virus (HIV)-1 vaccines, appears to be an effective way to elicit such immune responses.

Animals↗

Alterations in the course of experimental syphilis associated with concurrent simian immunodeficiency virus infection.

Case reports suggest that the course of syphilis is altered in patients infected with human immunodeficiency virus (HIV). To investigate this issue, a model of syphilis in rhesus macaques with and without simian immunodeficiency virus (SIV) was developed. After intradermal inoculation with Treponema pallidum, 2 SIV-infected monkeys had persistent ulcerative primary lesions and 1 developed secondary syphilis. Two SIV-uninfected controls developed transient nonulcerative primary lesions. Only the controls showed consistent VDRL antibody responses. In contrast, reciprocal antibody titers to T. pallidum detected by microhemagglutination were higher in SIV-infected animals (greater than or equal to 20,480) than controls (greater than or equal to 1280). All 4 animals developed a full range of T. pallidum antigen-specific antibodies shown by immunoblot and had similar peak lymphocyte proliferative responses to T. pallidum antigens. These results support the contention that retrovirus-induced immunodeficiency delays clearance of T. pallidum from sites of infection and may impair the humoral immune response to syphilis.

Animals↗

Transmission of SIVMne from female to male Macaca nemestrina.

Three SIVMne-infected female pigtailed macaques (Macaca nemestrina) were mated with two SIV-negative males. The females exhibited signs of SAIDS and SIVMne was readily isolated from peripheral blood mononuclear cells (PBMC). Both males became infected with SIVMne, developed SAIDS, and died. This is the first documented case of the transmission of SIVMne between adult macaques housed together. Although transmission through scratching or biting cannot be ruled out, heterosexual transmission appears the most likely mode of SIVMne transmission in this study.

Animals↗

Serum cholesterol level and mortality findings for men screened in the Multiple Risk Factor Intervention Trial. Multiple Risk Factor Intervention Trial Research Group.

BACKGROUND: With increased efforts to lower serum cholesterol levels, it is important to quantify associations between serum cholesterol level and causes of death other than coronary heart disease, for which an etiologic relationship has been established. METHODS: For an average of 12 years, 350,977 men aged 35 to 57 years who had been screened for the Multiple Risk Factor Intervention Trial were followed up following a single standardized measurement of serum cholesterol level and other coronary heart disease risk factors; 21,499 deaths were identified. RESULTS: A strong, positive, graded relationship was evident between serum cholesterol level measured at initial screening and death from coronary heart disease. This relationship persisted over the 12-year follow-up period. No association was noted between serum cholesterol level and stroke. The absence of an association overall was due to different relationships of serum cholesterol level with intracranial hemorrhage and nonhemorrhagic stroke. For the latter, a positive, graded association with serum cholesterol level was evident. For intracranial hemorrhage, cholesterol levels less than 4.14 mmol/L (less than 160 mg/dL) were associated with a twofold increase in risk. A serum cholesterol level less than 4.14 mmol/L (less than 160 mg/dL) was also associated with a significantly increased risk of death from cancer of the liver and pancreas; digestive diseases, particularly hepatic cirrhosis; suicide; and alcohol dependence syndrome. In addition, significant inverse graded associations were found between serum cholesterol level and cancers of the lung, lymphatic, and hematopoietic systems, and chronic obstructive pulmonary disease. No significant associations were found of serum cholesterol level with death from colon cancer, with accidental deaths, or with homicides. Overall, the inverse association between serum cholesterol level and most cancers weakened with increasing follow-up but did not disappear. The association between cholesterol level and death due to cancer of the lung and liver, chronic obstructive pulmonary disease, cirrhosis, and suicide weakened little over follow-up. CONCLUSIONS: The association of serum cholesterol with specific causes of death varies in direction, strength, gradation, and persistence. Further research on the determinants of low serum cholesterol level in populations and long-term follow-up of participants in clinical trials are necessary to assess whether inverse associations with noncardiovascular disease causes of death are consequences of noncardiovascular disease, whether serum cholesterol level and noncardiovascular disease are both consequences of other factors, or whether these associations are causal.

Adult↗

The ratio of ankle and arm arterial pressure as an independent predictor of mortality.

We carefully ascertained deaths for a cohort of 744 patients who had undergone noninvasive testing for lower extremity peripheral arterial disease (PAD) in a university affiliated, community hospital. Using a ratio of the ankle and brachial blood pressures (ABI) of less than 0.85 as the criteria, the relative risk (RR) for total mortality associated with PAD was 2.36 (95% CL = 1.60, 3.48) after adjusting for baseline covariates in a proportional hazards model. There was a strong trend for increasing risk with decreasing ABI (P less than 0.0001). Specific causes of death for which survival was directly related to the magnitude of ABI were myocardial infarctions, and deaths other than vascular disease and cancer. There was no relationship between ABI and the risk of mortality from cancer. The mortality experience of those with normal ABI was very similar to that of the general U.S. population (age adjusted RR = 1.14, 95% CL = 0.78, 1.61), whereas the risk for those with an ABI less than 0.4 was markedly elevated in comparison to the U.S. population (RR = 4.49, 95% CL = 3.52, 5.64). Our results suggest that the relatively technically simple measure of the ratio of ankle to brachial blood pressures, if low, carries a very poor prognosis and should prompt investigation and treatment of atherosclerotic disease in other vascular systems.

Aged↗

Systolic Hypertension of the Elderly Program (SHEP). Part 10: Analysis.

The SHEP is a randomized, placebo-controlled trial that will follow standard clinical trial principles in analyzing data relating to its proposed hypotheses. The protocol has stated a priori the main objective as well as the secondary subgroup hypotheses. Sample size calculations for SHEP have accounted for dropins to and drop-outs from active therapy as well as for the risk of nonstroke death. The sample size achieved (4,736 participants) should be adequate to address the proposed questions. Monitoring procedures have been described and established. A data and safety monitoring board that uses these procedures is closely following the data from the trial. The board will periodically examine the data to determine whether termination of the study is warranted.

Health Services for the Aged↗

Age-related prognosis after acute myocardial infarction (the Multicenter Diltiazem Postinfarction Trial).

The basis for the excess mortality with age after acute myocardial infarction (AMI) is not clear, nor is it known whether the mode of death is altered with age. Age-related factors predictive of mortality and age-related mechanisms of the 333 deaths were examined in 2,466 patients who were enrolled in a placebo-controlled trial to determine the effect of diltiazem on mortality and reinfarction after AMI. There were 3 age groups with increasing mortality rates: ages 25 to 49 (n = 499), 50 to 64 (n = 1,228) and 65 to 75 years (n = 739). There was a significant age-related increase in the proportion of patients with baseline risk factors. These baseline characteristics did not differ by treatment (placebo vs diltiazem). However, multivariate survivorship analysis still identified age as an independent risk factor for cardiac death. The proportion of arrhythmic and myocardial failure deaths did not differ by treatment or age group.

Adult↗

Experimental infection of pig-tailed macaques (Macaca nemestrina) with Campylobacter cinaedi and Campylobacter fennelliae.

Campylobacter cinaedi and C. fennelliae have been associated with proctocolitis, bacteremia, and asymptomatic rectal infection, primarily in homosexual men. To more directly assess the pathogenic role of these organisms, we studied their disease-producing potential in 12- to 25-day-old pig-tailed macaques (Macaca nemestrina). Four infant monkeys were challenged with 10(8) to 10(9) C. cinaedi, three were challenged with C. fennelliae, two were challenged with C. jejuni, and one received no microorganisms. Watery or loose stools without associated fever or fecal leukocytes developed 3 to 7 days postinoculation in all of the animals given C. cinaedi, C. fennelliae, and C. jejuni, but not in the control animal. Stool cultures were simultaneously positive and remained so in the animals challenged with C. cinaedi or C. fennelliae for 3 weeks after inoculation despite the resolution of clinical illness. All of the animals challenged with C. cinaedi and C. fennelliae became bacteremic, and three had clinical evidence of septicemia. Histopathologic evaluation of rectal biopsies (five animals) and necropsy (one animal) showed no evidence of mucosal disruption. Specific immunoglobulin M and immunoglobulin G antibody responses occurred in all of the animals challenged with C. cinaedi and C. fennelliae, as determined by enzyme-linked immunosorbent assay and immunoblotting. We conclude that C. cinaedi and C. fennelliae consistently produce a diarrheal illness accompanied by bacteremia and followed by prolonged gastrointestinal colonization in M. nemestrina.

Animals↗

Clinical and parasitologic aspects of cryptosporidiosis in nonhuman primates.

Eighty-one cases of acute cryptosporidiosis were diagnosed among 157 (52%) infant primates, predominantly Macaca nemestrina, housed in the nursery unit of the Washington Regional Primate Research Center. The mean age at onset of oocyst passage was 38 +/- 25 days. The outbreak was confined to the nursery and no cases were detected among juvenile or adult primates housed in other rooms within the colony. All but one animal manifested symptoms of enteric infection, including severe diarrhea and dehydration. Infected animals excreted oocysts for a mean of 36 days (range 7-78 days). No reinfections occurred. Cryptosporidium was the second most common enteric pathogen detected in the population, after Campylobacter jejuni. The risk of infection was related to the length of time the animal was housed in the nursery and to social interaction with other monkeys. These findings are relevant to the understanding of the epidemiology of cryptosporidiosis among human infants and children in environments with close social interactions and minimal learned personal hygiene practices.

Animals↗

Maternal transmission of type D simian retrovirus (SRV-2) in pigtailed macaques.

Pregnant macaques were used as a natural model for maternal-infant transmission of SRV-2 retrovirus. Fifty-one pregnant females were placed into one of four virus/antibody groups. Nonviremic mothers produced 100% virus-negative offspring at birth. In contrast, viremic mothers produced offspring which were 17% virus-negative and 83% virus-positive at birth. SRV-2 infection occurred principally in utero by the transplacental route. Infants born to viremic mothers exhibited low birth weight, prematurity, high perinatal death, and increased incidence of SAIDS.

Animals↗

Inoculation of Macaca fascicularis with simian immunodeficiency virus, SIVmne immunologic, serologic, and pathologic changes.

Previous studies had tested the susceptibility of two macaque species, Macaca nemestrina and M. mulatta, to infection with the primate lymphotropic lentivirus SIVmne. In this report we describe the results obtained after infecting eleven M. fascicularis with SIVmne. Six of the animals had previously been immunized with a recombinant vaccinia virus expressing the envelope gene of HIV-1. All eleven animals became seropositive. To date ten animals have died 43 to 155 weeks post infection of an AIDS-like disease.

Animals↗

Protection of macaques against simian AIDS by immunization with a recombinant vaccinia virus expressing the envelope glycoproteins of simian type D retrovirus.

Simian AIDS (SAIDS) is an endemic disease of macaques that shares many characteristics with AIDS in humans. SAIDS is etiologically linked to infection by a type D retrovirus, SAIDS retrovirus (SRV). Immunization with an inactivated whole-virus vaccine was shown to protect macaques against infection by SRV serotype 1. To identify the antigen(s) responsible for eliciting protective immunity, we have constructed a recombinant vaccinia virus (v-senv5) that expresses the envelope glycoproteins of SRV serotype 2 (SRV-2/W). Pig-tailed macaques (Macaca nemestrina) immunized with v-senv5 showed lymphoproliferative responses to purified SRV-2/W. They also generated antibodies that neutralized SRV-2/W infectivity in vitro and mediated antibody-dependent cellular cytotoxicity against SRV-2-infected cells. Four v-senv5-immunized animals, together with four control animals, were challenged intravenously with 5 x 10(3) tissue culture infectious doses of SRV-2/W. As early as 2 weeks after challenge, three of four control animals became viremic, and two of these three animals also seroconverted. The animal that was viremic but remained antibody negative died of symptoms of SRV infection 6 1/2 weeks after challenge. In contrast, all four v-senv5-immunized animals remained healthy, virus-free, and seropositive against only the immunizing envelope antigens. These results indicate that immunization with a recombinant vaccinia virus expressing the envelope antigens of SRV-2/W protects primates from infection by a retrovirus that causes immunodeficiency diseases.

Animals↗

Transmission of the simian immunodeficiency virus SIVmne in macaques and baboons.

A primate lymphotropic lentivirus was isolated on Hut 78 cells after cocultivation of a lymph node from a macaque that died with malignant lymphoma. In earlier studies SIV/Mne was inoculated into 17 macaques and two baboons. All of the macaques became viremic and seropositive. Fifteen of the macaques succumbed to a classic AIDS-like disease, whereas the baboons did not become viremic. The SIV/Mne virus has now been molecularly cloned and inoculated into Macaca nemestrina and baboons. A new transmission study has been initiated to test the effects of route and dosage on disease.

Animals↗