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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

2-Chloro-4-(trifluoromethyl)pyrimidine-5-N-(3',5'- bis(trifluoromethyl)phenyl)-carboxamide: a potent inhibitor of NF-kappa B- and AP-1-mediated gene expression identified using solution-phase combinatorial chemistry.

Described is the identification of a novel series of compounds that blocks the activation of two key transcription factors, AP-1 and NF-kappa B. These transcription factors regulate the expression of several critical proinflammatory proteins and cytokines and represent attractive targets for drug discovery. Through the use of high throughput screening and solution-phase parallel synthesis, inhibitors of both NF-kappa B and AP-1 were identified. In subsequent testing, these compounds were also shown to block both IL-2 and IL-8 levels in the same cells. One of the most potent compounds in this series, 28, was active in several animal models of inflammation and immunosuppression, thus validating the importance of AP-1 and NF-kappa B as potential therapeutic targets. The synthesis and preliminary structure-activity relationships of these compounds is addressed.

Actins

Pitfalls in neuroepidemiologic research.

In neuroepidemiologic research, there are many pitfalls to trap unwary investigators, whether the project is a survey, a case-control study, or some other type of study. We briefly discuss pitfalls relating to: research preliminaries (e.g., failure to decide on study objectives); personnel and training (e.g., deficient training); data collection (e.g., ineffective supervision); data ownership and data sharing (disagreement about how the data will be used), and report preparation (e.g., failure to interpret results in the context of uncertainties arising from the design and implementation of the research). Awareness of these pitfalls will reduce the likelihood of flawed or ineffective neuroepidemiologic research.

Data Collection

Comparison of HIV-1 envelope-specific CD4+ T cell lines simultaneously established from peripheral blood mononuclear cells and lymph node biopsy in HIV-1-infected individuals.

HIV-1 envelope-specific CD4+ T cell lines were established simultaneously from PBMC and lymph node mononuclear cells of two HIV-1-infected patients. Three recombinant envelope proteins were used to establish the CD4+ T cell lines: gp160NL4-3, gp120IIIB, and gp120MN. Six T cell lines were established from the first patient, one for each Ag from each compartment, and four T cell lines, two per compartment, were established from the second patient. Each line was challenged with a panel of overlapping peptides spanning the entire gp120 sequence to define its T cell epitope specificity. The pattern of recognition for all the lines from any given patient was similar between compartments. Each patient had a different pattern of peptide recognition. TCR analysis showed a heterogeneous usage of Vbeta between lines with same peptide specificity and established from different compartments. These data suggest that the cellular immune response does not phenotypically vary between the peripheral blood and lymph node compartments, but demonstrates genotypic heterogeneity, showing possible redundancy of the immune response to HIV-1 gp160.

Acquired Immunodeficiency Syndrome

Prevalence of Parkinson's disease in Junín, Buenos Aires Province, Argentina.

We investigated the prevalence of Parkinson's disease (PD) in a South American city: Junín, Buenos Aires Province, Argentina. At dwellings systematically selected, the case finding involved household screenings and neurological examinations (i.e., a two-phase survey approach). Only persons 40 years of age or older were eligible (N = 7,765). There were 51 cases of PD identified, yielding a crude prevalence of 656.8 per 100,000 population. The age-specific prevalence was consistently higher in men than women, and it increased with advancing age for both sexes. In addition to prevalence figures. we present tallies related to clinical features of PD, as well as tallies related to other subtypes of parkinsonism.

Adult

A population perspective on diagnostic criteria for Parkinson's disease.

For Parkinson's disease (PD), little is known about how the choice of diagnostic criteria affects research results. Using data on PD from three community studies (from Argentina, the Netherlands, Italy), we compared the impact on prevalence of several sets of diagnostic criteria. Each set was based on cardinal signs--resting tremor, bradykinesia, rigidity, impaired postural reflexes--and required that other parkinsonism be excluded. Some sets had additional requirements related to duration of symptoms, asymmetry of signs, or response to medication. In terms of prevalence, much lower estimates were associated with the requirements of asymmetry of signs and response to medication. The assessment of these clinical features may not be practical in community studies. Impaired postural reflexes, as a cardinal sign, seemed superfluous. For community studies of PD, we recommend the following diagnostic criteria: at least two of resting tremor, bradykinesia, or rigidity, in the absence of other apparent causes of parkinsonism.

Age Distribution

Multiple defects in type III collagen synthesis are associated with the pathogenesis of abdominal aortic aneurysms.

Confluent skin fibroblast cultures were prepared from 40 patients diagnosed with and surgically treated for an abdominal aortic aneurysm. An analysis of secreted type I and type III collagen in the media of these fibroblast preparations revealed reduced secretion of type III collagen from six patients. DNA sequence analysis of the entire coding domain of the pro alpha 1 (III) collagen mRNA in skin fibroblast RNA from these six patients revealed a C to T substitution at nucleotide 607 in one of the probands that would result in the replacement of a leucine residue with phenylalanine in the second position of the first tripeptide repeat in the triple-helical domain of type III collagen. Allele-specific hybridization analysis of genomic DNA from this proband and family members indicated that this non-glycine substitution probably contributed to the aneurysmal phenotype in this patient. No coding sequence mutations were found in the other five patients. It is clear from this study, therefore, that aberrant synthesis of type III collagen, as a consequence of both a coding sequence mutation and other factors contributing to reduced secretion of type III procollagen, will result in the development of an aortic aneurysm in a significant percentage of patients with this disease.

Age of Onset

Altered expression of bcl-2 and bax mRNA in amyotrophic lateral sclerosis spinal cord motor neurons.

One of the primary neurodegenerative events occurring in amyotrophic lateral sclerosis (ALS) is the selective loss of spinal cord alpha motor neurons. To study the potential role of apoptosis in the degeneration of these motor neurons, in situ hybridization was used to measure the expression of two apoptotic cell death genes, bcl-2 and bax, in control and ALS lumbar spinal cord sections. The strongest hybridization signal for bcl-2 mRNA in neurological and nonneurological control spinal cords was found primarily in lamina IX alpha motor neurons, while a weaker hybridization signal was found in neurons of Clarke's nucleus and the proper sensory nucleus of the dorsal horn. Surviving lamina IX motor neurons in ALS spinal cord sections also expressed bcl-2 mRNA, but at levels that were significantly and selectively decreased (4.7-fold) compared with controls. bax mRNA hybridization signal was detected in several cells throughout the gray matter in control and ALS lumbar spinal cord, but was significantly and selectively increased (2.8-fold) in ALS motor neurons. Given the proposed interactive roles of these genes in apoptosis, the present findings favor a scenario in which this mode of cell death would contribute to spinal cord motor neuron degeneration in ALS.

Adult

Occupation, education, and Parkinson's disease: a case-control study in an Italian population.

Current epidemiologic data on the association between occupational exposures and Parkinson's disease (PD) are inconsistent. In a case-control study, we investigated the associations between occupation and PD and between education and PD. The cases (n = 62) were those identified in a prevalence survey (door-to-door, two-phase) of three Sicilian municipalities, as a November 1, 1987. We then randomly selected from the general population two controls for each case, matched for age ( +/- year), sex, and municipality (n = 124). Information on current and past occupations and education for cases and controls was obtained during the survey. Subjects who worked for most of their lives as farmers were not at increased risk of PD (OR = 0.6; 95% CI = 0.3-1.3). Neither were subjects who worked for most of their lives in other occupations (e.g., housewives, fishermen, factory workers, salesmen, craftsmen, clerks). PD was not associated with low education. Our findings suggest that farming, as a broad occupational category, does not play a major role in the causation of PD.

Adult

Validity and reliability of the preliminary NINDS neuropathologic criteria for progressive supranuclear palsy and related disorders.

We investigated the validity and reliability of diagnoses made by eight neuropathologists who used the preliminary NINDS neuropathologic diagnostic criteria for progressive supranuclear palsy (PSP) and related disorders. The specific disorders were typical, atypical, and combined PSP, postencephalitic parkinsonism, corticobasal ganglionic degeneration, and Pick's disease. These disorders were chosen because of the difficulties in their neuropathologic differentiation. We assessed validity by measuring sensitivity and positive predictive value. Reliability was evaluated by measuring pairwise and group agreement. From a total of 62 histologic cases, each neuropathologist independently classified 16 to 19 cases for the pairwise analysis and 5 to 6 cases for the group analysis. The neuropathologists were unaware of the study design, unfamiliar with the assigned cases, and initially had no clinical information about the cases. Our results showed that with routine sampling and staining methods, neuropathologic examination alone was not fully adequate for differentiating the disorders. The main difficulties were discriminating the subtypes of PSP and separating postencephalitic parkinsonism from PSP. Corticobasal ganglionic degeneration and Pick's disease were less difficult to distinguish from PSP. The addition of minimal clinical information contributed to the accuracy of the diagnosis. On the basis of results obtained, we propose clinicopathologic diagnostic criteria to improve on the NINDS criteria.

Aged

Motor neuron disease on Guam: geographic and familial occurrence, 1956-85.

We investigated the geographic and familial occurrence of motor neuron disease (MND) on Guam, and then considered etiologic hypotheses related to cycad use and metal intoxication. The research was based on 303 Chamorros from Guam and 3 Chamorros from other Mariana Islands, all with MND onset on Guam during 1956-85. Inarajan and Umatac, two southern districts, each had, for both sexes combined, an average incidence rate significantly higher than the corresponding overall rate for Guam. Also, for each sex, geographic patterns of incidence were significantly related to 1) socioeconomic level (men only), 2) cycasin concentrations in cycad flour samples (men and women), 3) iron concentrations in water samples (men and women), 4) silicon concentrations in water samples (men only), and 5) cobalt and nickel concentrations in soil samples (men and women). The MND risk in susceptible sibships was about 7-28 times greater than that in the general population. The cycad hypothesis conforms somewhat better than the metal intoxication hypothesis with the data presented.

Female

Efficacy of synthetic peptide-containing surfactant in the treatment of respiratory distress syndrome in preterm infant rhesus monkeys.

Studies were conducted to assess the efficacy and safety of a synthetic peptide-containing surfactant in the treatment of respiratory distress syndrome (RDS) in preterm (approximately 80% of normal gestation) infant rhesus monkeys. Surfactant was prepared consisting of the phospholipids dipalmitoylphosphatidyl choline and palmitoyl-oleoyl phosphatidyl glycerol and a synthetic peptide modeled after surfactant protein B (SP-B), "KL4-Surfactant" contained a peptide having the sequence KLLLLKLLLLKLLLLKLLLLK, where "K" is lysine and "L" is leucine. The peptide was selected because it mimics the repeating stretches of hydrophobic residues with intermittent basic hydrophilic residues seen in SP-B. KL4-Surfactant was shown to have biophysical activity assessed as the ability to lower surface tension at an air-liquid interface in a pulsating bubble surfactometer. Thirty premature rhesus monkeys were treated shortly after birth with one dose of KL4-Surfactant. The arterial to alveolar oxygen partial pressure ratio (a/A) was found to rise from a pretreatment level of 0.11 +/- 0.01 (mean +/- SEM), indicative of severe RDS, to 0.40 +/- 0.02 at 12-13 h post-treatment. The improvement in oxygenation persisted throughout the study period, with a mean a/A at 22-23 h of 0.45 +/- 0.07. Chest radiographs and gross and microscopic examination of the lungs all confirmed the reversal of the atelectasis seen before treatment. Animals treated with a dose of 200 mg/kg showed a faster, more consistent, and greater response than did a group treated with an average dose of 127 mg/kg. There was no evidence of toxicity after treatment with the higher dose as demonstrated by physiologic, hematologic, biochemical, and pathologic data. The importance of the peptide in the synthetic surfactant was apparent from the results obtained with a control group of nine premature monkeys treated with a non-peptide-containing surfactant; the a/A of this group was 0.15 +/- 0.03 at nine hours of age as compared with a value of 0.38 +/- 0.02 for 30 comparable animals receiving KL4-Surfactant.

1,2-Dipalmitoylphosphatidylcholine

Functional results in oral cavity reconstruction using reinnervated versus nonreinnervated free fasciocutaneous grafts.

Recent advances in free-tissue transfer have given the otolaryngologist--head and neck surgeon a number of reliable options for reconstruction of the oral cavity following ablative procedures. One recent modification has been the transfer of free reinnervated fasciocutaneous grafts in the hope of enhancing oral rehabilitation following surgery. To assess the efficacy of this modification, a protocol was established to retrospectively evaluate patients that received either reinnervated or non-reinnervated free-tissue transfers. Factors including site, surgical resection, type of tissue transfer, and follow-up period were controlled. Evaluation of free-graft sensory return and quality of life was carried out through physical examination and patient interview. Speech assessment was carried out using standardized tests of intelligibility administered by a speech pathologist. Swallowing assessment was carried out with videocinefluoroscopic and scintigraphic techniques, and the oropharyngeal swallow efficiency was calculated. Sensory return in the reinnervate free grafts was superior; however, there was not statistical difference between groups in the speech and swallowing tests. Quality of life was judged to be good in both groups. Sensory return and functional outcome in intraoral reconstruction after tumour ablation was reviewed and discussed

Adult

Constrained peptide analogues of transforming growth factor-alpha residues cysteine 21-32 are mitogenically active. Use of proline mimetics to enhance biological potency.

Two proline mimetics, the enantiomers of 2-aza-bicyclo[2,2,1]heptane-3-carboxylic acid, have been incorporated in place of Pro30 into synthetic peptides based on the B-loop beta-sheet sequence of human transforming growth factor-alpha (TGF-alpha) (residues Cys21-Cys32). The peptides were further modified by inclusion of an N-terminal phenylalanine and constrained by formation of an intramolecular disulfide bond. While no mitogenic response was observed in the parental NR6 cell line, the peptides stimulated DNA synthesis in NR6/HER cells (NR6 fibroblasts transfected with the human epidermal growth factor receptor). Induction of DNA synthesis was dose dependent, with EC50 values in the range 130-330 microM; in the presence of low doses of TGF-alpha, the mitogenic effect of the peptides was additive, up to the plateau response achieved by maximal doses of TGF-alpha alone. These effects are consistent with the peptides acting via the same mechanism as TGF-alpha. Analysis of the structure of the peptides by NMR indicated that the presence of the mimetics significantly increased the propensity of the peptidyl-proline bond to adopt the cis conformation. These data confirm the role of the beta-sheet in receptor activation, and emphasize the importance of presentation of peptides in an appropriate conformation for recognition.

Amino Acid Sequence

Aberrant splicing of the type III procollagen mRNA leads to intracellular degradation of the protein in a patient with Ehlers-Danlos type IV.

Ehlers-Danlos syndrome type IV (EDS IV) is an autosomal dominant disorder characterized by fragile skin, blood vessels, and internal organs and associated with decreased production, secretion, or thermal stability of type III procollagen. Mutations in the gene for type III procollagen have been identified in patients exhibiting decreased secretion or thermal stability of the protein, but no defect has been elucidated to explain the decreased production of type III procollagen in some patients with EDS IV. We report on a patient with a moderate case of EDS IV who produced decreased amounts of type III procollagen despite normal levels of translatable type III procollagen mRNA. S1 nuclease analysis of the type III procollagen mRNA indicated a defect in the region encoding exon 27. Sequence analysis of cDNA clones and genomic fragments generated by polymerase chain reaction amplification revealed that sequences encoded by exon 27 were absent from 3 out of 5 cDNA clones and that a G at the +5 position of the splice donor site in intron 27 was changed to an A in one allele of the patient's type III procollagen gene. Using a cDNA-genomic DNA hybrid probe in S1 nuclease analysis, fragments consistent with mRNA species containing and lacking exon 27 were detected in a 1:1 ratio. Pulse label and chase experiments in the presence or absence of brefeldin A indicated that most of the type III procollagen molecules synthesized by the patient's fibroblasts were not secreted into the medium but were degraded in the endoplasmic reticulum-Golgi compartment by a nonlysosomal mechanism.

Adult