Title VII funding is associated with more family physicians and more physicians serving the underserved

Title VII funding of departments of family medicine at U.S. medical schools is significantly associated with expansion of the primary care physician workforce and increased accessibility to physicians for the residents of rural and underserved areas. Title VII has been successful in achieving its stated goals and has had an important role in addressing U.S. physician workforce policy issues.

Germline mutations in the ribonuclease L gene in families showing linkage with HPC1

Although prostate cancer is the most common non-cutaneous malignancy diagnosed in men in the United States, little is known about inherited factors that influence its genetic predisposition. Here we report that germline mutations in the gene encoding 2'-5'-oligoadenylate(2-5A)-dependent RNase L (RNASEL) segregate in prostate cancer families that show linkage to the HPC1 (hereditary prostate cancer 1) region at 1q24-25 (ref. 9). We identified RNASEL by a positional cloning/candidate gene method, and show that a nonsense mutation and a mutation in an initiation codon of RNASEL segregate independently in two HPC1-linked families. Inactive RNASEL alleles are present at a low frequency in the general population. RNASEL regulates cell proliferation and apoptosis through the interferon-regulated 2-5A pathway and has been suggested to be a candidate tumor suppressor gene. We found that microdissected tumors with a germline mutation showed loss of heterozygosity and loss of RNase L protein, and that RNASEL activity was reduced in lymphoblasts from heterozyogous individuals compared with family members who were homozygous with respect to the wildtype allele. Thus, germline mutations in RNASEL may be of diagnostic value, and the 2-5A pathway might provide opportunities for developing therapies for those with prostate cancer.

Concordance of interstitial cystitis in monozygotic and dizygotic twin pairs

Our objective was to determine whether there is a greater concordance of interstitial cystitis (IC) among monozygotic than dizygotic twins. Members of the Interstitial Cystitis Association (ICA) who responded to a survey about first-degree family members with IC symptoms or confirmed IC were requested to identify themselves if they were 1 of a twin pair. Each twin respondent and co-twin were then evaluated via a questionnaire and acquisition of hydrodistention reports as to their meeting modified National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) criteria for IC. Of the co-twins of 8 monozygotic twin respondents, 2 had probable and 3 had confirmed IC compared with none of the co-twins of the 26 dizygotic twin respondents (including 15 female co-twins). There is a greater concordance of IC among monozygotic than dizygotic twin pairs suggesting a genetic susceptibility to IC.

Reducing physician vulnerability to professional liability claims: what practices make a difference?

Physicians--both "good" and "bad"--may find themselves targeted in medical malpractice lawsuits for reasons not necessarily related to recognized acts of commission or omission. As a result, taking appropriate steps to reduce their vulnerability to claims that may eventually be brought against them makes good sense from a risk management perspective. This article looks at the frequency, severity, reasons for, and "misadventures" associated with one physician-owned medical malpractice company's professional liability claims and offers selected practice management strategies that can help enhance physicians' defensibility in the event they are sued.

Empirical evaluation of genome scans for linkage of a quantitative trait associated with a complex disorder

Nonparametric sib-pair analysis (Haseman-Elston) was used to search for evidence of linkage between a putative locus for a complex quantitative trait Q1 and genome-wide markers (367 markers from 10 chromosomes) for the first 100 replicates of nuclear family data. The characteristics of the statistically positive linkage results [the magnitude of p-values (p), the number of supporting flanking markers, and the percentage of positive replicates] were compared for true linkage (major and minor genes) and false positive evidence for linkage. Discriminant analysis was used to evaluate which characteristics of these statistically positive linkage results are good indicators to discriminate true linkage from false positive evidence for linkage. Sensitivity and false positive rates of several proposed criteria for linkage, as well as the criteria based on our results were evaluated. The relationship between the map location of the marker with the lowest p-value and the map location of the true underlying gene was also evaluated, which provided useful information for fine mapping and replication studies.

The horse homolog of congenital aniridia conforms to codominant inheritance

Anterior segment dysgenesis syndrome occurs frequently in Rocky Mountain horses and has two distinct ocular phenotypes: (1) large cysts originating from the temporal ciliary body or peripheral retina and (2) multiple anterior segment anomalies including ciliary cysts, iris hypoplasia, iridocorneal adhesions and opacification, nuclear cataract, and megalocornea. To determine if anterior segment dysgenesis syndrome is heritable in horses we performed ophthalmic examinations and collected pedigree information on horses (n = 516) in an extended Rocky Mountain horse pedigree. Logistic regressive segregation analysis of a subset of animals (n = 337) in which the ocular phenotypes of progeny and both parents were known indicated that the codominant inheritance model best fit the data. This model predicted cyst phenotype expression in heterozygous animals and multiple anterior segment anomalies in homozygous animals. Several cases of nonpenetrance of the cyst phenotype were detected in one lineage. The close resemblance between the inheritance and lesions observed in Small eye mice and rats, humans with congenital aniridia or anterior segment malformation, and horses with anterior segment dysgenesis syndrome supported the conclusion that anterior segment dysgenesis syndrome in the horse may be homologous to similar ophthalmic anomalies in other species.

In Swedish families with hereditary prostate cancer, linkage to the HPC1 locus on chromosome 1q24-25 is restricted to families with early-onset prostate cancer

Prostate cancer clusters in some families, and an estimated 5%-10% of all cases are estimated to result from inheritance of prostate cancer-susceptibility genes. We previously reported evidence of linkage to the 1q24-25 region (HPC1) in 91 North American and Swedish families each with multiple cases of prostate cancer (Smith et al. 1996). In the present report we analyze 40 (12 original and 28 newly identified) Swedish families with hereditary prostate cancer (HPC) that, on the basis of 40 markers spanning a 25-cM interval within 1q24-25, have evidence of linkage. In the complete set of families, a maximum two-point LOD score of 1.10 was observed at D1S413 (at a recombination fraction [theta] of.1), with a maximum NPL (nonparametric linkage) Z score of 1.64 at D1S202 (P=.05). The evidence of linkage to this region originated almost exclusively from the subset of 12 early-onset (age <65 years) families, which yielded a maximum LOD score of 2.38 at D1S413 (straight theta=0) and an NPL Z score of 1.95 at D1S422 (P=.03). Estimates from heterogeneity tests suggest that, within Sweden, as many as 50% of early-onset families had evidence of linkage to the HPC1 region. These results are consistent with the hypothesis of linkage to HPC1 in a subset of families with prostate cancer, particularly those with an early age at diagnosis.

In planta localization of a beta-1,4-endoglucanase secreted by Heterodera glycines

Polyclonal sera specific to beta-1,4-endoglucanases (cellulases) synthesized in the subventral esophageal gland cells of the soybean cyst nematode, Heterodera glycines, were used to provide the first identification of a nematode esophageal gland protein that is secreted into host plant tissue. Sera generated to proteins encoded by Hg-eng-1 and Hg-eng-2 (endoglucanases) did not cross-react with soybean root proteins on Western blots (immunoblots) or in immunofluorescence microscopy of noninoculated (control) soybean root sections. In cross sections of soybean roots at 24 h after inoculation of roots with second-stage juveniles of H. glycines, HG-ENG-1 was localized within the nematode's subventral gland cells and was not detected in root tissue. HG-ENG-2 was localized within the subventral gland cells and was secreted from the juvenile's stylet into root cortical tissue at 24 h after inoculation of roots with second-stage juveniles of H. glycines. HG-ENG-2 was localized along the juvenile's migratory path through the root cortex.

Evidence for a prostate cancer susceptibility locus on the X chromosome

Over 200,000 new prostate cancer cases are diagnosed in the United States each year, accounting for more than 35% of all cancer cases affecting men, and resulting in 40,000 deaths annually. Attempts to characterize genes predisposing to prostate cancer have been hampered by a high phenocopy rate, the late age of onset of the disease and, in the absence of distinguishing clinical features, the inability to stratify patients into subgroups relative to suspected genetic locus heterogeneity. We previously performed a genome-wide search for hereditary prostate cancer (HPC) genes, finding evidence of a prostate cancer susceptibility locus on chromosome 1 (termed HPC1; ref. 2). Here we present evidence for the location of a second prostate cancer susceptibility gene, which by heterogeneity estimates accounts for approximately 16% of HPC cases. This HPC locus resides on the X chromosome (Xq27-28), a finding consistent with results of previous population-based studies suggesting an X-linked mode of HPC inheritance. Linkage to Xq27-28 was observed in a combined study population of 360 prostate cancer families collected at four independent sites in North America, Finland and Sweden. A maximum two-point lod score of 4.60 was observed at DXS1113, theta=0.26, in the combined data set. Parametric multipoint and non-parametric analyses provided results consistent with the two-point analysis. Significant evidence for genetic locus heterogeneity was observed, with similar estimates of the proportion of linked families in each separate family collection. Genetic mapping of the locus represents an important initial step in the identification of an X-linked gene implicated in the aetiology of HPC.

The impact of the Mammography Quality Standards Act on the availability of mammography facilities

BACKGROUND

The Mammography Quality Standards Act (MQSA) became effective October 1, 1994, and requires all mammography facilities to meet quality standards as promulgated by the Food and Drug Administration (FDA). The FDA undertook an assessment of the MQSA federal certification requirements on the availability of mammography facilities.

METHODS

A survey of states on mammography facility closures between October 1, 1993, and October 1, 1994, was conducted. MapInfo software was used to link zip codes to demographic databases. The characteristics of closed facilities were compared to certified facilities as of December 15, 1994.

RESULTS

A total of 369 facilities (3.5%) had closed. This closure rate was comparable to previous years' rates (2.5-10%). As of December 15, 1994, 10,142 certified facilities were operating. Relative to their distribution in the United States, closures in rural areas were proportional, but there were more facility closures in the minority areas and in poverty areas. However, the relative distributions of facilities to these areas' populations were unchanged.

CONCLUSIONS

Impact on facility availability has been minimal.

Initial genomic scan of the NIMH genetics initiative bipolar pedigrees: chromosomes 3, 5, 15, 16, 17, and 22

As part of the four-center NIMH Genetics Initiative on Bipolar Disorder we carried out a genomic scan of chromosomes 3, 5, 15, 16,17, and 22. Genotyping was performed on a set of 540 DNAs from 97 families, enriched for affected relative pairs and parents where available. We report here the results of the initial 74 markers that have been typed on this set of DNAs. The average distance between markers (theta) was 12.3 cM. Nonparametric analysis of excess allele sharing among affected sibling pairs used the SIBPAL program of the S.A.G.E. package to test three hierarchical models of affected status. D16S2619 gave some evidence of linkage to bipolar disorder, with P = 0.006 for Model II (in which bipolar 1, bipolar 2 and schizoaffective-bipolar type individuals are considered affected). Nearby markers also showed increased allele sharing. A second interesting region was toward the telomere of chromosome 5q, where D5S1456 and nearby markers showed increased allele sharing; for D5S1456, P = 0.05, 0.015 and 0.008 as the models of affected status become more broad. MOD score analysis also supported the possible presence of a susceptibility locus in this region of chromosome 5. A pair of adjacent markers on chromosome 3, D3S2405 and D3S3038, showed a modest increased allele sharing in the broad model. Several isolated markers had excess allele sharing at the P < 0.05 level under a single model. D15S217 showed a MOD score of 2.37 (P < 0.025). Multipoint analysis flagged the region of chromosome 22 around D22S533 as the most interesting. Thus, several regions showed modest evidence for linkage to bipolar disorder in this initial genomic scan of these chromosomes, including broad regions near previous reports of possible linkage.

ApoE-4 and age at onset of Alzheimer's disease: the NIMH genetics initiative

OBJECTIVE

To explore the impact of apoE-4 on Alzheimer's disease (AD) and its age at onset.

DESIGN

A genetic linkage study using affected relative pairs, predominantly siblings.

SETTING

Three academic medical centers ascertained subjects from memory disorder clinics, nursing homes, and the local community.

SUBJECTS

310 families including 679 subjects with AD by NINCDS/ADRDA and/or Khachaturian criteria and 231 unaffected subjects.

OUTCOME MEASURE

ApoE genotype. ANALYTIC METHODS: Association, affected pedigree member, sibling pair, and lod score analyses.

RESULTS

ApoE-4 was strongly associated with AD in this sample (allele frequency = 0.46 vs. 0.14 in controls, p < 0.000001). Results of lod score, affected pedigree member analysis, and sib-pair analysis also supported apoE-4 as a risk factor for AD. When the sample was stratified on family mean age at onset, the risk conferred by apoE-4 was most marked in the 61 to 65 age group. Individuals with two copies of apoE-4 had a significantly lower age at onset than those with one or no copies (66.4 vs. 72.0, p < 0.001), but individuals with one copy did not differ from those with none. Within families, the individual with the earliest age at onset had, on average, significantly more apoE-4 alleles (p < 0.0001) than the individual with the latest onset.

DISCUSSION

This work supports previous reports of an association between apoE-4 and the development of AD and demonstrates that apoE-4 exerts its maximal effect before age 70. These findings have important implications for the potential use of apoE genotyping for diagnosis and prediction of disease. They also underscore the need to identify additional genetic factors involved in AD with onset beyond age 70 years.

Follow-up of a report of a potential linkage for schizophrenia on chromosome 22q12-q13.1: Part 2

A collaboration involving four groups of investigators (Johns Hopkins University/Massachusetts Institute of Technology; Medical College of Virginia/The Health Research Board, Dublin; Institute of Psychiatry, London/University of Wales, Cardiff; Centre National de la Recherche Scientifique, Paris) was organized to confirm results suggestive of a schizophrenia susceptibility locus on chromosome 22 identified by the JHU/MIT group after a random search of the genome. Diagnostic, laboratory, and analytical reliability exercises were conducted among the groups to ensure uniformity of procedures. Data from genotyping of 3 dinucleotide repeat polymorphisms (at the loci D22S268, IL2RB, D22S307) for a combined replication sample of 256 families, each having 2 or more affected individuals with DNA, were analysed using a complex autosomal dominant model. This study provided no evidence for linkage or heterogeneity for the region 22q12-q13 under this model. We conclude that if this region confers susceptibility to schizophrenia, it must be in only a small proportion of families. Collaborative efforts to obtain large samples must continue to play an important role in the genetic search for clues to complex psychiatric disorders such as schizophrenia.

Sequential strategy to identify a susceptibility gene for schizophrenia: report of potential linkage on chromosome 22q12-q13.1: Part 1

To identify genes responsible for the susceptibility for schizophrenia, and to test the hypothesis that schizophrenia is etiologically heterogeneous, we have studied 39 multiplex families from a systematic sample of schizophrenic patients. Using a complex autosomal dominant model, which considers only those with a diagnosis of schizophrenia or schizoaffective disorder as affected, a random search of the genome for detection of linkage was undertaken. Pairwise linkage analyses suggest a potential linkage (LRH = 34.7 or maximum lod score = 1.54) for one region (22q12-q13.1). Reanalyses, varying parameters in the dominant model, maximized the LRH at 660.7 (maximum lod score 2.82). This finding is of sufficient interest to warrant further investigation through collaborative studies.

Collagen synthesis by normal and fibrotic human lung fibroblasts and the effect of transforming growth factor-beta

Collagen accumulation is a major feature of pulmonary fibrosis and other fibrotic lesions. We have studied the synthesis of collagens in fibroblasts cultured from normal and fibrotic human lung specimens and evaluated how it is affected by transforming growth factor-beta (TGF-beta). Fibroblasts were obtained from normal and fibrotic adult human lungs (n = 11; normal = 6, idiopathic pulmonary fibrosis = 5). They were exposed to TGF-beta and pulse-labeled with [3H]proline and [3H]glycine. Collagen production was measured as bacterial collagenase-susceptible radioactivity, and collagen mRNA levels were determined by a solution hybridization assay using labeled procollagen alpha 1[I] cDNA clone HF677 as probe. Synthesis of collagen types I, III, and V were assessed after separating them by DEAE-cellulose chromatography and SDS-polyacrylamide gel electrophoresis. The results showed that both normal and fibrotic lung fibroblasts synthesized similar amounts of collagen. Type I was the major collagen species synthesized by both normal and fibrotic cell types, and the relative proportion of type I, III, and V collagens was similar in both cell types. TGF-beta caused a two to fourfold increase in stimulation of collagen production and collagen mRNA levels, and no differences were detected in the response of normal and fibrotic lung fibroblasts. All collagen types were stimulated by the TGF-beta. TGF-beta did not increase fibroblast proliferation and the majority of normal and fibrotic lung cells exposed to TGF-beta remained in G1 phase of the cell cycle. We conclude that fibroblasts of normal and fibrotic human synthesize similar amounts of collagens.(ABSTRACT TRUNCATED AT 250 WORDS)

Crustacean peptidergic neurons in culture show immediate outgrowth in simple medium

The survival and outgrowth of neurons in culture has usually required conditioning factors. We now report that crustacean neurons, taken from the peptidergic neurosecretory system of the eyestalk of crabs (Cardisoma carnifex) and lobsters (Panulirus marginatus), show immediate outgrowth, sustained for a week or more, in defined medium as simple as physiological saline with glucose and glutamine. The neurons show peptide hormone immunoreactivity that is prominent at growth cones, exhibit differences in form correlated with their immunoreactivity, release peptides to the medium, and have voltage-dependent currents, including a well-sustained Ca current. Cd blocks secretion, growth, and the Ca current. Peptidergic secretory neurons may be able to utilize existing membrane from their store of granules and already active synthetic, transport, and secretory mechanisms for immediate outgrowth.

Computer methods for sampling, reconstruction, display and analysis of retinal whole mounts

We are quantifying the distribution of photoreceptors and ganglion cells in human retina with the goal of establishing a reliable anatomical database which may be compared to information about visual function. We required a representation of retinal cell distributions which facilitated collection, analysis, and display of morphometric data from the entire retina of a large number of eyes. We report computer methods to (1) reconstruct the original retinal sphere from a three-piece whole mount preparation; (2) sample the retina in a manner which allowed description of approximately radially symmetrical cell distributions and avoided both undersampling (which produces interpolation artifacts) and oversampling (which wastes time); (3) interpolate between data points in order to produce plots of cell density along arbitrary meridians and maps of average cell density from several eyes; (4) specify locations on the retinal surface using a spherical coordinate system with its primary axis through the fovea; and (5) produce color-coded maps of cell distributions in a standard perimetric projection.

Aluminum in foci of pelvic calcification in neoplastic and nonneoplastic conditions

Both aluminum and calcium are present in many pelvic concretions that have traditionally been attributed to calcium and phosphorus alone. There is considerable variation in both the amount and the distribution of aluminum when it is present.

In vivo studies with two phospholipase C fractions from Pseudomonas aeruginosa

Two phospholipase C fractions were detected in culture supernatants from Pseudomonas aeruginosa ATCC 19660, PAO1, and D10C by preparative polyacrylamide gel electrophoresis. Both hemolytic fractions from strain ATCC 19660 were isolated by polyacrylamide gel electrophoresis and were found to cause paralysis, death, dermonecrosis, footpad swelling, and vascular permeability in mice. In vivo toxicity was directly associated with enzymatic activity.

Principal-components analysis of prehistoric South Asian crania

Principal-components analysis is used as an investigative procedure for establishing temporal, spatial and evolutionary-developmental changes in Homo sapiens skeletal specimens from prehistoric sites in South Asia. It is concluded that cranial variables which cluster hunter-gatherers within the sample are related to facial architecture with respect to robusticity and size. Older models presumably reflecting genetic affinities and racial classifications of prehistoric South Asians which were based upon univariate-bivariate statistical analyses are not supported by the results of this principal-components analysis.