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Biomedical subjects

D W Anderson

Publications and source records attributed to D W Anderson.

At least 19 recordsLinked to original sources

Revised estimate of the prevalence of multiple sclerosis in the United States.

Using three adjustments, we have revised a 1976 prevalence count for multiple sclerosis in the United States. The adjustments were made to data from a US national survey; they used 1990 population projections from the US Bureau of the Census, and results of investigations conducted in Weld and Larimer Countries, Colorado, and Olmsted County, Minnesota. It is estimated that approximately 250,000 to 350,000 persons in the United States in 1990 had physician-diagnosed multiple sclerosis.

Age Factors

Validating screening instruments for neuroepidemiologic surveys: experience in Sicily. Sicilian Neuro-Epidemiologic Study (SNES) Group.

In a hospital setting in Sicily, we assessed a screening instrument developed for a prevalence survey of parkinsonism, peripheral neuropathies, stroke, and epilepsy. The subjects consisted of (1) hospital patients with any of the above-mentioned diseases, to investigate sensitivity; and (2) hospital visitors free of all these diseases, to investigate specificity. The standard for comparison was a clinical evaluation based on specified criteria. Trained interviewers administered the screening instrument, asking subjects to answer symptom questions and to perform simple physical tasks. For the questions and tasks together, the sensitivity estimates were 100% for parkinsonism (n = 21), 96% for peripheral neuropathies (n = 22), 96% for stroke (n = 22), and 96% for epilepsy (n = 22), while the specificity estimate was 86% (n = 21). Analogous estimates were computed for the set of questions, for the set of tasks, and for each question and task individually. Despite limitations in our approach, we concluded that the screening instrument would be adequate for its intended use.

Adult

Treatment of paranasal sinus malignancy: the BCCA experience.

A retrospective analysis was undertaken of 119 patients treated at the British Columbia Cancer Agency (BCCA) with a diagnosis of paranasal sinus malignancy. All patients from 1970 to 1987 were included in the review. A comparison is drawn between main treatment modalities, namely primary radiotherapy, primary surgical resection and combined therapy. Clinical characteristics of this relatively rare lesion are elucidated. Recommendations regarding optimal therapy are made on the basis of this data.

Adolescent

Seasonal and geographical variation of organochlorine residues in birds from northwest Mexico.

Eight species of birds (129 individuals) were collected from three agricultural areas with long histories of pesticide use in northwestern Mexico. Plucked carcasses were analyzed for organochlorine (OC) pesticides and polychlorobiphenyls (PCBs). DDE was found in all of the samples and at higher levels than other OCs. Mean (geometric) DDE concentrations varied from 0.04 (microgram/g) ppm in mourning doves (Zenaida macroura) to 5.05 ppm in double-crested cormorants (Phalacrocorax auritus). Hexachlorocyclohexane (HCH) was detected in 95% of the samples, but at lower levels than DDE. Hexachlorobenzene (HCB) residues were detected more frequently in birds from Mexicali (62%, p less than 0.05) than in those from Yaqui and Culiacan. HCH and HCB concentrations were significantly higher in birds from Mexicali during the winter than in the summer (p less than 0.05), indicating accumulation of these compounds during that period. Other OCs such as DDT, DDD, dieldrin, oxychlordane, heptachlor expoxide, endosulfan, and endrin were found at lower levels and less frequently. PCBs (quantitated as Aroclor 1260) were found mostly in cattle egrets (Bubulcus ibis) and cormorants at the three locations. Overall, concentrations of OCs were higher for Mexicali than for Yaqui and Culiacan (p less than 0.01). In a few cases, DDE levels were above those that might adversely affect birds.

Animals

Comparison of the ulcerogenic properties of tepoxalin with those of non-steroidal anti-inflammatory drugs (NSAIDs).

The ability of tepoxalin to render the gastric mucosa susceptible to injury by a topically applied irritant was compared to that of indomethacin, naproxen and diclofenac. While the three NSAIDs significantly increased the extent of mucosal damage at doses in the 1-30 mg/kg range, tepoxalin failed to significantly augment damage at doses of up to 300 mg/kg. Daily treatment with tepoxalin (10-100 mg/kg) for 4 days also did not significantly affect the susceptibility of the gastric mucosa to damage. The absence of ulcerogenic properties of tepoxalin at doses previously shown to be anti-inflammatory may be related to its relative lack of activity as an inhibitor of gastric prostaglandin synthesis, or to its 5-lipoxygenase inhibitory activity.

Animals

Rapid detection of antigen-specific mouse IgE by enzyme-linked immunosorbent assay (ELISA).

A rapid, sensitive, antigen-specific mouse IgE capture ELISA is described. A monoclonal rat anti-mouse IgE was used as the capture antibody, and a DNP-coupled BSA-biotinylated conjugate along with a peroxidase-avidin-biotin complex was utilized as the detection system. The lower detection limit of this assay is 8.5 ng/ml of antigen-specific IgE. With some modifications, this assay can be employed to screen for antigen specific antibodies of other isotypes and subtypes.

Animals

Localization of metastatic adrenal cortical carcinoma with Ga-67.

Data are limited on the localization of Ga-67 in primary or metastatic adrenal cortical carcinoma. We report the localization of Ga-67 to pathologically confirmed adrenal cortical carcinoma metastatic to the lung. A review of the literature revealed four patients have previously been reported to have metastatic adrenal cortical carcinoma detected on Ga-67 scan. Gallium imaging may be useful in the evaluation of patients with adrenal cortical carcinoma. SPECT imaging should further improve lesion resolution and localization.

Adrenal Cortex Neoplasms

Door-to-door prevalence survey of neurological diseases in a Sicilian population. Background and methods. The Sicilian Neuro-Epidemiologic Study (SNES) Group.

In three municipalities of Sicily, a prevalence survey of major neurological diseases was conducted door-to-door using screening and examination to find cases. This was the first large-scale neuroepidemiologic survey of that type undertaken in Italy: 24,496 persons were screened yielding 1,538 positives, of whom 1,408 were examined directly by neurologists and 110 were evaluated on the basis of existing medical documentation. In the article, we provide (1) a description of the population investigated and the survey methods employed; (2) details of the cooperation and the attrition experienced in the survey; and (3) age and sex tallies for the study population, including some on education level and occupation.

Adolescent

Patterns of acquiring parkinsonism-dementia complex on Guam. 1944 through 1985.

For 1944 through 1985, documented clinical descriptions compatible with a diagnosis of parkinsonism-dementia complex were found in 363 Chamorros (including mixed Chamorros) and three Filipino immigrants who had lived on Guam before onset. Downward trends in age-adjusted incidence rates and upward trends in age at onset were seen for Chamorros of both sexes. Since 1980, new cases have occurred only among persons over 50 years of age, whereas a younger age at onset had been noted in the past. Evidence suggests that the length of the latent period varied widely (up to decades) and increased with time, the risk of acquiring parkinsonism-dementia complex had declined since the late 1950s, and the critical age of exposure to an unknown factor in the environment on Guam appears to have been during adolescence or adulthood.

Adult

Geographic patterns of parkinsonism-dementia complex on Guam. 1956 through 1985.

Average annual age-adjusted incidence rates of parkinsonism-dementia complex were obtained for the 19 election districts of Guam from 1956 through 1985. The highest rates were found in the southern and central districts, and the lowest rates were found in the northern and western districts. Geographic and temporal patterns of incidence were associated with socioeconomic status but not with geochemical factors. The risk of parkinsonism-dementia complex in susceptible sibships was much higher than that in the general population--even in districts with the highest incidence rates, but especially in districts with the lowest incidence rates. Our evidence tends to support the hypothesis that multiple factors linked to cycad use play an important role in the cause of PDC. Hypotheses related to metal exposure and simple genetic factors were unsatisfactory explanations for the epidemiologic patterns observed.

Dementia

Serological confirmation of human T-lymphotropic virus type I infection in healthy blood and plasma donors.

We wished to develop criteria for serological confirmation of human T-lymphotropic virus type I (HTLV-I) infection in healthy donors. Selected serum or plasma samples reactive by HTLV-I enzyme immunosorbent assay or gel-agglutination assays with at least one viral-specific band on Western immunoblot (WIB) were tested in six laboratories by four WIBs and four radioimmunoprecipitation assays (RIPAs) for antibodies to HTLV-I proteins encoded by gag (p19 and p24), env (gp46 and/or gp61), and tax (p40x) genes. One hundred forty-two donor sera were obtained from 38 Japanese, 69 American, and 35 Caribbean blood or plasma donors. Among these samples, WIB assays appeared more sensitive to p24 antibodies, whereas RIPAs were significantly more sensitive to gp61 antibodies. All sera (137) with gp61 antibodies had p24 antibodies. Of the 137 sera positive for p24 and gp61 antibodies, p19 antibodies were detected in 129 sera, and p40x antibodies were detected in 108. In sera with p19 antibodies and antibodies to env- or tax-encoded proteins, p24 antibodies were always present. Antibodies to p40x were not found in the absence of gp61 antibodies. Virological evidence of infection was found in seven American donors by lymphocyte coculture (one HTLV-I, one HTLV-II) or by polymerase chain reaction (three HTLV-I, two HTLV-II). Sera from all seven donors showed p24 and gp46 and/or gp61 antibodies. We suggest that seroreactivity to both p24 and gp46 and/or gp61 by WIB or RIPA or both are suitable criteria to confirm but not to distinguish HTLV-I and HTLV-II infections.

Blood Donors

Rheumatic heart disease in a patient with acquired immunodeficiency syndrome.

Acute rheumatic heart disease (RHD) with Aschoff nodules and biventricular dilation was diagnosed at autopsy in a patient with acquired immunodeficiency syndrome who died of pneumonia due to Pneumocystis carinii. The relationship of acute RHD and human immunodeficiency virus-associated immune deficiency is discussed.

Acquired Immunodeficiency Syndrome

Structure-activity studies of trichothecenes: cytotoxicity of analogues and reaction products derived from T-2 toxin and neosolaniol.

Forty-two analogues and reaction products derived from T-2 toxin or neosolaniol were assayed for their cytotoxicity to cultured mouse lymphoma cells. Structure-activity relationships confirmed the stereospecific nature of the cytotoxic action of T-2. Cytotoxicity was particularly susceptible to changes at C3, C4, C9, and C10 but was relatively unaffected by changes at C8, which appears to represent a region of steric tolerance in the interaction of T-2 with a cellular constituent. The most potent compounds were T-2, diacetoxyscirpenol, and a series of C8 ester analogues 11 and 31-35.

Animals

Molecular cloning and nucleotide sequence of the alpha-toxin (phospholipase C) of Clostridium perfringens.

A fragment of DNA containing the gene coding for the phospholipase C (alpha-toxin) of Clostridium perfringens was cloned into Escherichia coli. The cloned DNA appeared to code only for the alpha-toxin and contained both the coding region and its associated gene promoter. The nucleotide sequence of the cloned DNA was determined, and an open reading frame was identified which encoded a protein with a molecular weight of 42,528. By comparison of the gene sequence with the N-terminal amino acid sequence of the protein, a 28-amino-acid signal sequence was identified. The gene promoter showed considerable homology with the E. coli sigma 55 consensus promoter sequences, and this may explain why the gene was expressed by E. coli. The cloned gene product appeared to be virtually identical to the native protein. A 77-amino-acid stretch that was close to the N terminus of the alpha-toxin showed considerable homology with similarly located regions of the Bacillus cereus phosphatidylcholine, preferring phospholipase C and weaker homology with the phospholipase C from Pseudomonas aeruginosa.

Amino Acid Sequence

Frequency of myocarditis, left ventricular dysfunction and ventricular tachycardia in the acquired immune deficiency syndrome.

To evaluate possible relations between clinical and histopathologic cardiac findings in patients with the acquired immune deficiency syndrome (AIDS), 58 consecutively autopsied AIDS patients were reviewed retrospectively. Twenty-six (45%) had histopathologic myocarditis. Fifteen of these 26 (58%) had greater than or equal to 1 clinical cardiac abnormalities: 6 had congestive heart failure or left ventricular (LV) dysfunction, or both, 4 had ventricular tachycardia (VT), 10 had electrocardiographic abnormalities and 4 had pericardial abnormalities. Of the 32 patients without myocarditis, 6 (19%) had pericardial or electrocardiographic abnormalities, or both, but none had congestive heart failure, LV dysfunction or VT. Overall, clinical cardiac abnormalities were found in 21 patients (36%). Patients with myocarditis had a significantly higher incidence of clinical cardiac abnormalities than patients without myocarditis (58 vs 19%, p less than 0.01). All patients with congestive heart failure, LV dysfunction or VT had myocarditis. Thus, serious clinical cardiac abnormalities were common in patients with AIDS and were associated with myocarditis.

Acquired Immunodeficiency Syndrome