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Biomedical subjects

R G Roberts

Publications and source records attributed to R G Roberts.

At least 37 records · Page 2Linked to original sources
PubMed2001

How widespread are the symptoms of an overactive bladder and how are they managed? A population-based prevalence study.

OBJECTIVE: To determine the prevalence of chronic and debilitating symptoms of the overactive bladder, defined here as the presence of chronic frequency, urgency and urge incontinence (either alone or in any combination), and presumed to be caused by involuntary detrusor contractions. Subjects and methods Data were collected using a population-based survey (conducted by telephone or direct interview) of men and women aged >/= 40 years, selected from the general population in France, Germany, Italy, Spain, Sweden and the United Kingdom, using a random stratified approach. The main outcome measures were: prevalence of urinary frequency (> 8 micturitions/24 h), urgency and urge incontinence; the proportion of participants who had sought medical advice for symptoms of an overactive bladder; and current or previous therapy received for these symptoms. RESULTS: In all, 16 776 interviews were conducted in the six European countries. The overall prevalence of overactive bladder symptoms in individuals aged >/= 40 years was 16.6%. Frequency (85%) was the most commonly reported symptom, followed by urgency (54%) and urge incontinence (36%). The prevalence of overactive bladder symptoms increased with advancing age. Overall, 60% of respondents with symptoms had consulted a doctor but only 27% were currently receiving treatment. Conclusion Symptoms of an overactive bladder, of which frequency and urgency are as bothersome as urge incontinence, are highly prevalent in the general population. However, only a few affected individuals currently receive treatment. Taken together, such findings indicate that there is considerable scope for improvement in terms of how physicians diagnose and treat this condition.

Activities of Daily Living↗
PubMed2001

Nesprins: a novel family of spectrin-repeat-containing proteins that localize to the nuclear membrane in multiple tissues.

In search of vascular smooth muscle cell differentiation markers, we identified two genes encoding members of a new family of type II integral membrane proteins. Both are ubiquitously expressed, and tissue-specific alternative mRNA initiation and splicing generate at least two major isoforms of each protein, with the smaller isoforms being truncated at the N-terminus. We have named these proteins nesprin-1 and -2 for nuclear envelope spectrin repeat, as they are characterized by the presence of multiple, clustered spectrin repeats, bipartite nuclear localization sequences and a conserved C-terminal, single transmembrane domain. Transient transfection of EGFP-fusion expression constructs demonstrated their localization to the nuclear membrane with a novel C-terminal, TM-domain-containing sequence essential for perinuclear localization. Using antibodies to nesprin-1, we documented its colocalization with LAP1, emerin and lamins at the nuclear envelope, and immunogold labeling confirmed its presence at the nuclear envelope and in the nucleus where it colocalized with heterochromatin. Nesprin-1 is developmentally regulated in both smooth and skeletal muscle and is re-localized from the nuclear envelope to the nucleus and cytoplasm during C2C12 myoblast differentiation. These data and structural analogies with other proteins suggest that nesprins may function as 'dystrophins of the nucleus' to maintain nuclear organization and structural integrity.

Amino Acid Sequence↗
PubMed2000

Conservation of components of the dystrophin complex in Drosophila.

Defects in the dystrophin complex (DC) underlie several human genetic disorders, but our dissection of its function is complicated by potential redundancy of the multiple vertebrate isoforms of most DC components. We here complete our previous description of Drosophila dystrophin, and show that the fly retains all essential components of the DC, but with substantially less diversity. Seventeen known human components (three dystrophin-related proteins, two dystrobrevins, five sarcoglycans, five syntrophins, one dystroglycan and one sarcospan) appear to be reduced to eight in Drosophila (one, one, three, two, one and none, respectively). The simplicity of this system recommends it as a model for its human counterpart.

Amino Acid Sequence↗
PubMed2000

Association of dystrophin-related protein 2 (DRP2) with postsynaptic densities in rat brain.

The fundamental function of the membrane-associated cytoskeletal proteins dystrophin and utrophin remains unclear. To gain further insights into the dystrophin family of proteins, we have studied dystrophin-related protein 2 (DRP2), whose expression is largely confined to the vertebrate central nervous system. Both human and rat DRP2 are expressed from two alternative but neighboring transcriptional start sites and have simple transcript structures. Antibodies raised against DRP2 detect a characteristic quartet of bands ( approximately 100-120 kDa) in Western blots of rat brain. The DRP2 protein is associated with brain membrane fractions and highly enriched in the postsynaptic density. Immunohistochemistry shows DRP2 to be widely distributed in a punctate pattern on neuronal dendrites and in neuropil, with particular concentration in regions of the brain involved in cholinergic synaptic transmission. Given the presence of utrophin in the cholinergic neuromuscular junction, and perturbations of cholinergic transmission in dystrophin-deficient nematodes, our findings may suggest a role for DRP2 in the organization of central cholinergic synapses.

Animals↗
PubMed2000

Two novel members of the interleukin-1 receptor gene family, one deleted in Xp22.1-Xp21.3 mental retardation.

X-linked mental retardation is estimated to affect approximately 1 in 600 males. Although numerous genes responsible for syndromic mental retardation have been identified, the study of non-syndromic mental retardation suffers from intrinsic issues of genetic heterogeneity. During the investigation of three brothers with a contiguous gene deletion syndrome of Becker muscular dystrophy, glycerol kinase deficiency, congenital adrenal hypoplasia, and mental retardation, we found their dystrophin gene to be fused tail-to-tail with a gene encoding a novel member of the interleukin-1 receptor family, IL1RAPL1. This gene has a close relative in Xq22, which we call IL1RAPL2. Both IL1RAPL1 and IL1RAPL2 have novel C-terminal sequences not present in other related proteins, and are encoded by very large genes. The 1.8-megabase deletion in these patients removes not only the last exon of the dystrophin gene, the entire glycerol kinase and DAX-1 genes, and the MAGE-B gene cluster, but also three exons encoding the intracellular signalling domain of IL1RAPL1. The literature contains multiple reports of patients with non-syndromic mental retardation in association with an Xp22.1-Xp21.3 microdeletion of a marker which lies within the IL1RAPL1 gene. The gene is also wholly or partially deleted in patients with mental retardation as part of a contiguous deletion syndrome. We suggest that IL1RAPL1, and perhaps IL1RAPL2, are strong candidates for X-linked non-syndromic mental retardation loci, and that molecules resembling IL-1 and IL-18 play a role in the development or function of the central nervous system.

5' Untranslated Regions↗
PubMed1999

The human family of Deafness/Dystonia peptide (DDP) related mitochondrial import proteins.

The gene responsible for the human genetic neurodegenerative disorder DFN-1/MTS encodes a small protein known as deafness/dystonia peptide (DDP). It bears a strong resemblance to a recently characterized set of zinc-binding yeast proteins (Tim8p, Tim9p, Tim10p, Tim12p, and Tim13p) that are implicated in the import of a class of transmembrane carrier proteins from the cytoplasm to the mitochondrial inner membrane. We describe here the human complement of DDP/Tim-like proteins and establish the likely orthologous relationships between sequences from human, yeast, and other organisms. We also describe the expression patterns and chromosomal locations of their genes, which are candidate loci for autosomal recessive neurodegenerative disorders.

Amino Acid Sequence↗
PubMed1999

Evaluation of dysuria in men.

Men with pain or a burning sensation on urination should be evaluated with a thorough history, a focused physical examination and urinalysis (both urine dipstick and microscopic examination of the urine specimen). Although dysuria may be caused by anything that leads to inflammation of the urethal mucosa, it is most often the result of urinary tract infection. In younger patients, the infectious agent is usually a sexually transmitted organism such as Chlamydia trachomatis. In patients over 35 years of age, coliform bacteria predominate. Infection in older men most often occurs as a result of urinary stasis secondary to benign prostatic hyperplasia. Other conditions that may cause dysuria include renal calculus, genitourinary malignancy, spondyloarthropathy and medications. Successful treatment of dysuria depends on correct identification of its cause.

Constriction, Pathologic↗
PubMed1998

Prostate cancer screening and beliefs about treatment efficacy: a national survey of primary care physicians and urologists.

PURPOSE: To describe practice patterns and beliefs of primary care physicians and urologists regarding early detection and treatment of prostate cancer. SUBJECTS AND METHODS: National probability samples of primary care physicians (n=444) and urologists (n=394) completed mail survey instruments in 1995. Physicians were asked about their use of prostate-specific antigen (PSA) testing for men of different ages and their beliefs about the value of radical prostatectomy, external-beam radiation therapy, and watchful waiting for men with differing life expectancies. RESULTS: Most primary care physicians report doing PSA tests during routine examination of men older than 50 years of age. The majority say they continue to do them on patients over 80 years and to refer men with abnormal values for biopsy. In contrast, only a minority of urologists would recommend PSA tests or biopsy for abnormal values for men over 75 years of age. More than 80% of primary care physicians and urologists doubt the value of radical prostatectomy for men with < 10 years of life expectancy; more primary care physicians than urologists see probable survival benefit in radiation therapy for patients with life expectancy < 10 years (48% versus 36%) or > 10 years (67% versus 53%). Thirteen percent of primary care physicians and only 3% of urologists consider watchful waiting to be as appropriate as aggressive therapy for men with > 10 years of life expectancy. CONCLUSIONS: Primary care physicians are more aggressive about PSA testing and referral for biopsy than most urologists recommend. Both groups recommend PSA testing and believe that aggressive treatment is more beneficial than existing evidence indicates.

Adult↗
PubMed1998

Dystrophins in vertebrates and invertebrates.

Members of the dystrophin family of proteins perform a critical but incompletely characterized role in the maintenance of membrane-associated complexes at points of intercellular contact in many vertebrate cell types. They interact with, amongst others, the transmembrane laminin receptor dystroglycan, cytoskeletal actin and, indirectly, the intracellular membrane-associated signalling enzyme neuronal nitric oxide synthase (nNOS). Here we describe sequences of a range of dystrophin-related proteins from vertebrate and invertebrate animals (including the important model organism Drosophila melanogaster ) and infer an evolutionary history of this family and its relationship to the distantly related dystrobrevins. It appears that most metazoa possess sequences encoding a single highly conserved dystrophin-like protein in addition to a presumed distinct dystrobrevin, derived from an early duplication of an ancestral gene. In the vertebrates (but not the protochordate Amphioxus), the single invertebrate dystrophin-like gene has undergone serial duplication to generate at least three distinct genes encoding proteins which have adopted specialized roles. It is hoped that this broadening of the biology of the dystrophins will afford further opportunities for the advancement of our understanding of the fundamental defect underlying the variety of human genetic disorders which result from aberrant or absent dystrophin-associated complexes.

Animals↗
PubMed1998

Why family physicians deliver babies.

BACKGROUND: Numerous factors have been hypothesized to explain the steady decline of family physicians providing maternity care. Rather than exploring reasons for departure, we sought to learn why many family physicians choose to deliver babies. METHODS: A previously piloted questionnaire was mailed to 1300 family physicians who had attended continuing education programs related to pregnancy. The respondents were classified as: those who had always delivered babies (group 1: "Always Did"); those who had previously not delivered babies, but had started or planned to start doing deliveries (group 2: "Started Later or Plan"); and those who had never delivered babies or had previously delivered but stopped (group 3: "Will Not Do"). The study focused on the reasons respondents in the first two groups decided to deliver babies and contrasted their views with those of the third group. RESULTS: Five hundred seventy-five valid responses were returned (421 "Always Did"; 92 "Started Later or Plan"; 62 "Will Not Do"). Response patterns were similar for all geographic regions. Reasons for delivering babies that appeared with statistically significant frequency included personal enjoyment, adequate obstetrical training in residency, desire to care for younger families, and supportive obstetricians during residency. Reasons for not delivering babies included unacceptable lifestyle, a community's saturation of maternity caregivers, fear of law-suit, and absence of need to build a practice. CONCLUSIONS: Family physicians who deliver babies appear to be primarily motivated by personal enjoyment, followed by a desire to care for younger patients and adequate training in residency. Those who do not perform deliveries primarily cite the unacceptability of a maternity caregiver's lifestyle. The expectation of the practice and a lack of community need are also important influences on the decision of family physicians to deliver babies.

Adult↗
PubMed1997

Exon-intron organization of the human dystrophin gene.

Analysis of the exon-intron organization of the human dystrophin gene has been hampered by its enormous size. By using a YAC-based exon mapping approach and long PCR, we have succeeded in defining the size of the gene and its organization. Our results, compared with data on the distribution of deletion breakpoints by intron, elucidate the topography of the intragenic deletion-prone regions. Within the central high-frequency deletion region, the small, 6.6-kb, intron 49 shows a much higher density of deletion breakpoints than intron 44, which was previously believed to coincide with the most mutable zone of the gene. On the other hand, in the proximal part of the gene, deletion breakpoints do not preferentially occur in a few introns, but are spread over a large DNA segment containing introns 2 to 42.

Chromosome Mapping↗
PubMed1997

Expression of the dystrophin-related protein 2 (Drp2) transcript in the mouse.

We have recently characterised a new member of the dystrophin gene family, DRP2, and its murine counterpart, Drp2, which encode dystrophin-related protein 2 (DRP2). DRP2 is predicted to resemble certain short C-terminal isoforms of dystrophin and dystrophin-related protein 1 (DRP1 or utrophin). We describe here a comprehensive survey of Drp2 expression in the mouse by RT-PCR, and compare the expression profile of Drp2 with that of the related genes Dmd, Drp1 and Dag1 that encode all the known isoforms of dystrophin, DRP1/utrophin and a component of the dystrophin-associated protein complex, dystroglycan, respectively. Drp2 was shown to be expressed throughout the central nervous system (CNS) and in several peripheral tissues including the eye, kidney, teeth, oesophagus, colon, epididymis and ovary. The expression of Drp2 in the CNS was then further defined by in situ hybridization. Overall, the pattern of Drp2 expression corresponds to a subset of the brain regions known to express Dag1, and shows substantial overlap with regions that express various isoforms of dystrophin (particularly in the cerebral cortex, hippocampus and cerebellum). These data define the distribution of Drp2 expression in the mouse, and raise the possibility that in the CNS it may be an important component in neuronal dystrophin-associated complexes.

Animals↗