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Biomedical subjects

L Morris

Publications and source records attributed to L Morris.

At least 55 records · Page 3Linked to original sources
PubMed1999

Meningitis in a community with a high prevalence of tuberculosis and HIV infection.

OBJECTIVES: To evaluate the spectrum of aetiologies, and distinguishing clinical and laboratory features, of meningeal infection in a community with a high prevalence of tuberculosis (TB) and HIV infection. SETTING: A hospital serving mineworkers, originating from rural areas of Southern Africa. DESIGN: Prospective cohort of 60 consecutive lumbar punctures (LPs), performed for suspected meningitis. MEASUREMENTS: Clinical history and examination; concurrent cerebrospinal fluid (CSF) and blood samples; mortality status six months after entry to study. RESULTS: 38 of 57 patients (66.7%) were HIV-1 positive, 59.5% of whom had a CD4 count <200 cells/mm3. Nine patients had tuberculous meningitis (TBM) and two had tuberculomas; four developed disease while on TB therapy. There was one case of multidrug, and two of isoniazid-resistant TBM. There were nine episodes of cryptococcal meningitis (seven patients), nine of aseptic meningitis, two of neurosyphilis and 20 normal LPs, including four with AIDS dementia complex (ADC). Ten patients with meningococcal infection, part of a larger outbreak, were significantly younger (p=0.004). All patients with tuberculous, cryptococcal (most immune-suppressed p<0.001) and aseptic meningitis were HIV-1 positive. Within six months, 19 patients had died. Death was associated with HIV positivity (p=0.004), low CD4 count (p<0.001) and a diagnosis of cryptococcal meningitis, CNS TB or ADC. CONCLUSION: HIV has a major impact on the burden of disease and mortality, with a predominance of opportunistic chronic meningitides, despite a meningococcal outbreak, in this community. Of concern is the development of TBM despite therapy, and the emergence of drug-resistant strains.

AIDS Dementia Complex↗
PubMed1998

Improved cervical smear assessment using antibodies against proteins that regulate DNA replication.

Carcinoma of the cervix is one of the most common malignancies. Papanicolaou (Pap) smear tests have reduced mortality by up to 70%. Nevertheless their interpretation is notoriously difficult with high false-negative rates and frequently fatal consequences. We have addressed this problem by using affinity-purified antibodies against human proteins that regulate DNA replication, namely Cdc6 and Mcm5. These antibodies were applied to sections and smears of normal and diseased uterine cervix by using immunoperoxidase or immunofluorescence to detect abnormal precursor malignant cells. Antibodies against Cdc6 and Mcm5 stain abnormal cells in cervical smears and sections with remarkably high specificity and sensitivity. Proliferation markers Ki-67 and proliferating cell nuclear antigen are much less effective. The majority of abnormal precursor malignant cells are stained in both low-grade and high-grade squamous intraepithelial lesions. Immunostaining of cervical smears can be combined with the conventional Pap stain so that all the morphological information from the conventional method is conserved. Thus antibodies against proteins that regulate DNA replication can reduce the high false-negative rate of the Pap smear test and may facilitate mass automated screening.

Antibodies↗
PubMed1998

HIV-1 antigen-specific and -nonspecific B cell responses are sensitive to combination antiretroviral therapy.

We studied how combination antiviral therapy affects B cell abnormalities associated with HIV-1 infection, namely elevated circulating immunoglobulin (Ig)G antibody-secreting cell (ASC) frequencies and hypergammaglobulinemia. Within a few weeks of starting antiviral therapy, there is a marked decline in IgG-ASC frequency in both acutely and chronically infected people, whereas the hypergammaglobulinemia often present during chronic infection is more gradually resolved. These reductions are sustained while HIV-1 replication is suppressed. HIV-1 antigen-specific B cell responses are also affected by therapy, manifested by a rapid decline in circulating gp120-specific ASCs. Anti-gp120 titers slowly decrease in chronically infected individuals and usually fail to mature in acutely infected individuals who were promptly treated with antiretroviral therapy. Long-term nonprogressors have high titer antibody responses to HIV-1 antigens, but no detectable gp120-specific IgG-ASC, and normal (or subnormal) levels of total circulating IgG-ASC. Overall, we conclude that HIV-1 infection drives B cell hyperactivity, and that this polyclonal activation is rapidly responsive to decreases in viral replication caused by combination antiviral therapy.

Antiviral Agents↗
PubMed1998

Genetic characterization of HIV type 1 from migrant workers in three South African gold mines.

The phylogenetic relationships between 44 HIV-1 isolates from 43 infected subjects employed by three adjacent South African gold mines were investigated. The patients were migrant workers originating from rural areas of South Africa and the neighboring countries of Lesotho, Botswana, Swaziland, and Mozambique. Proviral HIV-1 DNA was subtyped using a heteroduplex mobility assay (HMA) based on the 700-bp V3-V5 region of the env gene. DNA sequence analysis was used to confirm the subtype designation and to determine phylogenetic relationships between isolates. All 44 HIV-1 isolates were identified as env subtype C using both HMA and phylogenetic analysis. These isolates did not show a distinct phylogenetic relatedness based on the geographic origins of the migrant workers or show close homology to other subtype C sequences from southern Africa or India. However, five clusters of closely related sequences were identified, mainly involving miners of disparate geographic origins, suggesting possible epidemiological linkage in these few cases. The characteristic tetrapeptide sequence, GPGQ, at the tip of the V3 loop of subtype C viruses was conserved in the predicted amino acid sequences of most isolates. The heterogeneity of HIV-1 sequences among migrant workers in a mining cohort suggests multiple introductions of HIV-1 subtype C into this population that are not apparently linked to the geographic origins of the patients.

Adolescent↗
PubMed1998

Locomotor stereotypy produced by dexbenzetimide and scopolamine is reduced by SKF 83566, not sulpiride.

Like amphetamine, scopolamine produces locomotor stereotypy (repetitive routes of locomotion) in an open field. To determine whether locomotor stereotypy is a common behavioral effect of anticholingeric agents, several doses of the anticholinergic dexbenzetimide were tested for the ability to produce locomotor stereotypy; like scopolamine, dexbenzetimide produced locomotor stereotypy. To investigate a possible role of dopamine in anticholinergic-induced locomotor stereotypy, we tested the ability of the dopamine D1 antagonist SKF 83566 and the D2 antagonist sulpiride to block the locomotor stereotypy induced by scopolamine as well as dexbenzetimide. SKF 83566 blocked scopolamine- and dexbenzetimide-induced locomotor stereotypy; sulpiride did not reduce dexbenzetimide-induced locomotor stereotypy, but enhanced scopolamine-induced locomotor stereotypy. Hyperlocomotion was reduced by both dopamine antagonists. Results are interpreted in support of the notion that dopamine is the likely candidate mediating locomotor stereotypy.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1998

Live births resulting from unintended pregnancies: an evaluation of synthetic state-based estimates.

OBJECTIVES: Most states lack information on the proportion of live births resulting from unintended pregnancies. We evaluated a potential solution to the lack of data, a synthetic state-based estimate of the percentage of live births resulting from unintended pregnancies for the state of Georgia. METHODS: We constructed the synthetic estimate by standardizing the 1995 National Survey of Family Growth data by the race, marital status, and age distribution of Georgia residents ages 15-44 years who delivered a live birth during 1990-1994. Two surveys conducted in Georgia during the same period that collected information on unintended pregnancies were used for comparison: the Georgia Women's Health Survey (GWHS) and the Georgia Pregnancy Risk Assessment Monitoring System (PRAMS). RESULTS: The synthetic estimate (35.2%, 95% CI = 33.5%-36.7%) was not statistically different from the GWHS estimate (39.6%, 95% CI = 35.7%-43.5%), but was significantly lower than the Georgia PRAMS estimate (49.0%, 95% CI = 45.5%-52.5%). When we stratified by race, marital status, and age, the synthetic and GWHS estimates were statistically similar except for married females and females ages 25-34 years, for whom the synthetic estimates were lower. For all groups of females, the synthetic estimates were statistically lower than the Georgia PRAMS estimates. CONCLUSIONS: The synthetic estimate can be a useful method for states that need to know the overall magnitude of the percentage of live births resulting from unintended pregnancy for purposes such as program planning.

Adolescent↗
PubMed1998

High human immunodeficiency virus type 1 RNA load in the cerebrospinal fluid from patients with lymphocytic meningitis.

Thirty-seven matched cerebrospinal fluid (CSF) and plasma samples from 34 human immunodeficiency virus type 1 (HIV-1)-infected patients with suspected meningitis were analyzed for levels of HIV-1 RNA and markers of inflammation. Patients with tuberculous (n = 9) or cryptococcal (n = 6) meningitis had the highest CSF virus loads, which in many cases exceeded the levels in plasma, compared with patients with meningococcal meningitis (n = 3), aseptic meningitis (n = 8), tuberculoma (n = 2), or AIDS dementia complex (n = 4) or with normal lumbar punctures (n = 3). CSF virus load correlated significantly with the number of infiltrating lymphocytes (r = .60, P < .001) but not with plasma virus load, the levels of beta2-microglobulin in the CSF, or the integrity of the blood-brain barrier. These data suggest significant intrathecal HIV-1 replication in patients with lymphocytic meningeal infections such as tuberculous and cryptococcal meningitis.

AIDS Dementia Complex↗
PubMed1998

Dual infective pathology in patients with cryptococcal meningitis.

Coinfection of the nervous system by two distinct nonviral organisms is uncommon and often undiagnosed. Medical teaching emphasizes that a single pathologic process should be sought; however, in the presence of severe immunocompromise this approach may not hold true. We describe seven HIV-1 seropositive patients with cryptococcal meningitis, three of whom had a proven nervous system infection with a second organism: concurrent tuberculous meningitis, a tuberculoma, and the first documented case of cryptococcal meningitis and neurosyphilis.

AIDS-Related Opportunistic Infections↗
PubMed1998

The decline in US teen pregnancy rates, 1990-1995.

OBJECTIVES: Estimate pregnancy, abortion, and birth rates for 1990 to 1995 for all teens, sexually experienced teens, and sexually active teens. DESISN: Retrospective analysis of national data on pregnancies, abortions, and births. Participants. US women aged 15 to 19 years. OUTCOME MEASURES: Annual pregnancy, abortion, and birth rates for 1990 to 1995 for women aged 15 to 19 years, with and without adjustments for sexual experience (ever had intercourse), and sexual activity (had intercourse within last 3 months). RESULTS: Approximately 40% of women aged 15 to 19 years were sexually active in 1995. Teen pregnancy rates were constant from 1990 to 1991. From 1991 to 1995, the annual pregnancy rate for women aged 15 to 19 years decreased by 13% to 83.6 per 1000. The percentage of teen pregnancies that ended in induced abortions decreased yearly; thus, the abortion rate decreased more than the birth rate (21% vs 9%). From 1988 to 1995, the proportion of sexually experienced teens decreased nonsignificantly. CONCLUSIONS: After a 9% rise from 1985 to 1990, teen pregnancy rates reached a turning point in 1991 and are now declining. Physicians should counsel their adolescent patients about responsible sexual behavior, including abstinence and proper use of regular and emergency contraception.

Abortion, Induced↗
PubMed1998

Increased cesarean section rates and emerging patterns of health insurance in Shanghai, China.

OBJECTIVES: This study examined the trend in cesarean section deliveries and the factors associated with it in the Minhang District of Shanghai, China. METHODS: A representative sample of the members of 2716 households in the district were interviewed in the fall of 1993. This study analyzed the data from 1959 married women of reproductive age with at least one live birth. RESULTS: During the past 3 decades, the proportion of infants born by cesarean section increased from 4.7% to 22.5%. Logistic regression analysis revealed that the highest cesarean section rate, which occurred in the most recent period of 1988 through 1993, was associated with form of medical payment, self-reported complications during pregnancy, higher birthweight, and maternal age. Government insurance pays all costs of cesarean sections and accounted for the highest proportion of the cesarean section rate. CONCLUSIONS: The high rates of cesarean sections in China are surprising given the lack of the factors that usually lead to cesarean sections. The increasing cesarean section rates may be an early indication that emerging forms of health insurance and fee-for-service payments to physicians will lead to an excessive emphasis on costly, high-technology medical care in China.

Adolescent↗
PubMed1998

FDA Modernization Act: implications for oncology.

The Food and Drug Administration (FDA) Modernization Act, signed into law on November 21, 1997, represents a sweeping review of existing standards for the approval, labeling, and promotion of prescription medicines. Certain sections of the act will influence access that oncologists and their patients have to new treatments and to information about those treatments. Major impacts of the act include: (1) continued funding of drug reviews by the FDA to assure a continuing stream of new drugs to prevent and treat disease; (2) providing greater flexibility in drug approval by permitting approval on the basis of one clinical trial and confirmatory evidence, and by instituting "fast track" designation to certain drugs that will permit approval on the basis of surrogate end points; (3) improving the access of physicians and patients to developing treatments by instituting a clinical trials databank and by authorizing the use of investigational products in emergencies; and (4) loosening restrictions on dissemination by drug companies of health, economic, and off-label use information, while maintaining incentives to investigate new uses for developing products.

Databases, Factual↗
PubMed1998

Governing at a distance: the elaboration of controls in British immigration.

This article considers the possibility that aspects of recent thinking on governmentality could be applied to the delimitation of rights and elaboration of controls in the policy and practice of British immigration over the period of Conservative rule. First, the complex of external strategies which interact to control and inhibit migration, including the discursive assertion of sovereign boundaries in the face of moves towards a frontier-free Europe are reviewed. Then, turning to official expressions of concern over public funds, the centrality of this rationale in the drive for correspondence between benefit regulations and immigration rules is documented. This drive, it is argued, is a key tactic in the development of internal controls, both as a basis for interagency cooperation and the means by which service providers can be encouraged to police migration. Finally, the paper shows how the rationality dictating these changes has itself been questioned and further elaborates the limits of "governmentality" in practice.

Demography↗