Publications by authors named "Rota T"

The balance of energetic losses and gains is of paramount importance for understanding and predicting the persistence of populations and ecosystem processes in a rapidly changing world. Previous studies suggested that metabolic rate often increases faster with warming than resource ingestion rate, leading to an energetic mismatch at high temperature. However, little is known about the ecological consequences of this energetic mismatch for population demography and ecosystem functions.

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While future climate scenarios predict declines in precipitations in many regions of the world, little is known of the mechanisms underlying community resilience to prolonged dry seasons, especially in 'naïve' Neotropical rainforests. Predictions of community resilience to intensifying drought are complicated by the fact that the underlying mechanisms are mediated by species' tolerance and resistance traits, as well as rescue through dispersal from source patches. We examined the contribution of in situ tolerance-resistance and immigration to community resilience, following drought events that ranged from the ambient norm to IPCC scenarios and extreme events.

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Ureteral valves with ureteral strictures are rare and the differential diagnosis is difficult to establish. Four cases are reported to present these aspects.

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Eight HIV-1 isolates from Venezuela have been characterized by nucleotide sequencing of the entire reverse transcriptase (RT)- and surface glycoprotein (gp 120)-coding regions. Average mutant frequencies were 2.5 x 10(-2) substitutions per nucleotide (s/nt) for the RT-coding region, and 10 x 10(-2) or 6.

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Human immunodeficiency virus (HIV) expression and replication are under tight regulatory control. We demonstrate that 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] enhances the replication of monocyte- and lymphocyte-tropic strains of HIV-1 up to 10,000-fold in monocyte cell lines, peripheral blood monocytes, and unfractionated peripheral blood mononuclear cells. 1,25(OH)2D3 is therefore one of the most potent regulators of HIV-1 replication described to date.

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Human immunodeficiency virus (HIV) has been detected in cervical secretions from HIV-infected women. We report the isolation of HIV from four cervical biopsy specimens. Cervicitis was shown by immunohistochemical staining in cervical biopsy specimens from four HIV-seropositive women; cervicitis was not found in cervical biopsy specimens from four HIV-seronegative women.

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Serum neutralizing antibodies against the human immunodeficiency virus were frequently detected in infected individuals, and low or absent serum neutralizing titers correlated with poor prognosis. Multiple diverse human immunodeficiency virus isolates were found to exhibit similar susceptibility to neutralization by a panel of human seropositive sera, suggesting that neutralizing antibodies are largely directed against conserved viral domains. Furthermore, utilizing antisera raised against a library of synthetic env peptides, four regions which are important in the neutralization process have been identified within both human immunodeficiency virus envelope glycoproteins (gp41 and gp120).

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Human T-cell lymphotropic virus type III (HTLV-III) has been isolated from neural tissues and cerebrospinal fluid (CSF) of patients with neurological syndromes associated with the acquired immune deficiency syndrome (AIDS) and the virus may be directly involved in the pathogenesis of the syndromes. To detect HTLV-III antigen in neural tissues from patients with AIDS, immunoperoxidase studies using a goat anti-HTLV-III serum were performed on frozen tissue sections of brain, spinal cord, and nerve from 13 patients with AIDS or HTLV-III-related neurological syndromes. HTLV-III was cultured from neural tissues or CSF in 11 of 13 of these patients.

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Normal blood-derived monocyte/macrophages were found to be susceptible to infection in vitro by human T lymphotropic virus type III (HTLV-III), the etiologic agent of the acquired immunodeficiency syndrome. In addition, HTLV-III was recovered from monocyte/macrophages of patients infected with this virus. The above findings raise the possibility that HTLV-III-infected monocyte/macrophages may serve as a vehicle for the dissemination of virus to target organs and as a reservoir for viral persistence, as has been shown for other lentiviruses including visna virus and caprine arthritis encephalitis virus.

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We conducted virus-isolation studies on 56 specimens from the nervous system of 45 patients in order to determine whether human T-cell lymphotropic virus Type III (HTLV-III) is directly involved in the pathogenesis of the neurologic disorders frequently encountered in the acquired immunodeficiency syndrome (AIDS) and the AIDS-related complex. We recovered HTLV-III from at least one specimen from 24 of 33 patients with AIDS-related neurologic syndromes. In one patient, HTLV-III was isolated from the cerebrospinal fluid during acute aseptic meningitis associated with HTLV-III seroconversion.

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Primary infection with the human T-lymphotropic virus type III (HTLV-III) was documented in three patients by virus isolation during acute illness and concurrent or subsequent HTLV-III seroconversion. All patients had fevers, rigors, arthralgias, and myalgias. Additional symptoms included truncal maculopapular rash, urticaria, abdominal cramps, and diarrhea.

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The effects of cytomegalovirus (CMV) infection on patient and allograft survival were determined in 1245 renal transplant recipients from 46 transplant centers. When an antilymphocyte preparation was administered to cadaveric allograft recipients, those at risk for primary CMV had a worse outcome than similar patients treated with prednisone and azathioprine (53.1% alive at 6 months with a functioning allograft vs.

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Recombinant human interferon alfa-A (rIFN alpha A) had a dose-related suppressive effect on human T lymphotropic virus type III (HTLV-III) replication in vitro in normal peripheral-blood mononuclear cells (PBMC). Both single-dose and multiple-dose regimens were inhibitory. Such inhibitory concentrations (4-1024 units/ml) were not toxic to PBMC in culture, and were within the ranges achievable in blood after injection.

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We studied the effects of human T-lymphotropic virus type I (HTLV-I) on human endothelial cells in vitro. During cocultivation with an HTLV-I producer cell line (C91/PL), endothelial cells formed characteristic multinucleated syncytial giant cells. Inoculation with concentrated cell-free supernatant fluid from C91/PL cultures produced similar cytopathic effects, which were neutralized by pretreatment with HTLV-I specific human serum.

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Human T-lymphotropic virus type III (HTLV-III) is the probable etiologic agent for the acquired immune deficiency syndrome (AIDS). HTLV-III was isolated from semen and blood of a healthy homosexual man whose serum contains antibodies to HTLV-III. The finding of virus in semen supports epidemiologic data that suggest that AIDS can be transmitted sexually.

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We have previously demonstrated that six weeks of prophylaxis with interferon-alpha delays cytomegalovirus excretion and decreases viremia in recipients of kidney transplants. In a double-blind trial to evaluate the effects of a longer course of prophylaxis, we gave either 3 X 10(6) units of interferon or placebo intramuscularly to 42 patients before transplant surgery was performed. After surgery, doses were given three times a week for six weeks and then twice a week for eight weeks (total of 102 X 10(6) units).

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Various techniques have been utilized for antigen solubilization, isolation, and purification. This report is the first to describe the isolation and purification of a type-specific antigen from Chlamydia trachomatis serotype A grown in cell culture. The type-specific antigen was prepared from Chlamydia trachomatis serotype A organisms grown in baby hamster kidney cells (BHK21).

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The application of cell culture techniques to the study of chlamydiae have led to isolation of C. trachomatis from a variety of syndromes, among which are nongonococcal urethritis, post-gonococcal urethritis, cervicitis, acute salpingitis, neonatal conjunctivitis, and pneumonia of infants. The methods currently employed fo chlamydia isolation are described, as well as the conditions which affect the infectivity of these organisms to cells in vitro.

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The immunolabeling characteristics of Rickettsia tsutsugamushi (Gilliam strain) were examined by using a purified immunoglobulin G fraction of antibody to R. tsutsugamushi raised in rabbits. Formalin-fixed rickettsiae were reacted with this antibody and then with ferritin-conjugated goat anti-rabbit Fc antibody.

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