Genetic susceptibility to visceral obesity and related clinical implications

This paper reviews evidence supporting the notion that genetic factors may have an influence on the determination of body fat distribution, particularly emphasizing the genetic susceptibility of visceral adipose tissue (AT) accumulation. The potential contribution of genetic susceptibility to the development of metabolic alterations in visceral obese individuals will also be reviewed. The contribution of genetic factors to the variation in body fat distribution is supported by studies in which racial differences in body fat distribution were reported. These ethnic differences suggest that body fat distribution may be influenced by some components of the genetic background which are shared among individuals of a given race. Furthermore, the familial aggregation and the resemblance between monozygotic twins that have been observed for anthropometric measurements of body fat distribution and for visceral AT accumulation measured by computed tomography, also suggest that genetic factors are involved in the determination of body fat distribution. Genetic susceptibility may also influence the relationship between visceral AT accumulation and the development of metabolic alterations. In this regard, it has been reported that the polymorphism of some genes (for example, the apolipoprotein (apo) E, apo B100 and lipoprotein lipase genes) is altering the relationship between visceral obesity and plasma lipoprotein-lipid levels. In conclusion, results presented in this paper suggest that genetic factors seem to have a significant influence on the propensity to accumulate AT in the visceral depot and that genetic factors also seem to affect the associations commonly reported between visceral obesity and the development of metabolic alterations.     

Genetic testing: Psychological aspects and implications.

As the number of genes associated with inherited disease continues to grow, researchers and practitioners in behavioral medicine will encounter complex psychological issues faced by individuals at risk for these diseases. A review of the literature concerning prenatal, carrier, and predictive genetic testing suggests that the severity of psychological risks posed by research-based genetic testing is not great. However, subgroups of individuals with particular psychological traits may be more vulnerable to adverse effects. Available data do not provide evidence that genetic testing promotes changes in health-related behaviors. Thus, although there may be less of a role for mental health professionals in the psychological counseling of genetic testing participants, there is a need for research and practice to facilitate health protective behaviors in response to genetic risk information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mannosidosis: clinical, morphologic, immunologic, and biochemical studies

The primary metabolic defect in mannosidosis is the deficiency of the acidic alpha-mannosidase A and B activites which results in the lysosomal accumulation of mannose-rich substrates. Out studies demonstrate that the enzymatic diagnosis of suspect homozygotes can be made reliably using plasma, isolated leukocytes, or cultured skin fibroblasts assayed carefully at the appropriate acidic pH. Immunologic studies of a mannosidosis homozygote revealed significant abnormalities of neutrophil function; these included a depressed chemotactic responsiveness and impaired phagocytosis of bacteria. Lymphocyte transformation studies showed a 20% of normal response to purified phytohemagglutinin and a 25% of normal response to concanavalin A. Three major components of alpha-mannosidase activity in normal human liver were resolved by ion exchange chromatography on DEAE-cellulose and electrophoresis on cellulose acetate gels. Electrophoresis of the liver extract from homozygote I with mannosidosis revealed only one band of activity which coelectrophoresed with the alpha-mannosidase C isozyme partially purified from normal liver. However, ion exchange chromatography revealed the presence of residual hepatic acidic activities; the residual A isozyme was eluted in a position corresponding to that of normal alpha-mannosidase A whereas the residual B activity was eluted at a slightly more electronegative position than that of normal B isozyme. The apparent Km values for alpha-mannosidase activity as determined from Linweaver-burk plots were 1.1 mM for normal liver and 0.9 mM for normal leukocytes. In contrast, the residual activity in these sources from homozygote 1 could not be saturated within the solubility range of the substrate; the apparent Km value was estimated at 15.4 mM in liver extracts. Zinc significantly lowered the apparent Km value of the acidic activity in normal liver (from 1.2 to 0.24 mM), whereas this metallic ion had little effect on the values for mannosidosis hepatic activity (from 15.4 to 12.3 mM). Unlike zinc, cobalt had its major effect on the acidic activity in the mannosidosis liver extract, lowering the apparent Km from 15.4 to 3.9 mM, whereas the apparent Km for the normal activity was increased from 1.2 to 1.9 mM. The residual acidic activities were markedly stimulated by zinc in both leukocytes (approximately 300%) and plasma ( approximately 400%) from the homozygotes and to a lesser extent in those sources from normal individuals. In contrast, cobalt enhanced the residual acidic activities in leukocytes (approximately 500%) and plasma (approximately 200%) from the homozygotes while inhibiting these acidic activities (78.9% and 47.7%, respectively) in normal individuals.     

Caprine mucopolysaccharidosis-IIID: clinical, biochemical, morphological and immunohistochemical characteristics

Laparoscopic antireflux surgery is rapidly replacing traditional operations for the treatment of medically refractory gastroesophageal reflux disease. These procedures are technically demanding. Troublesome side effects can be minimized by carefully selecting patients and using a meticulous and appropriate technique. Extensive follow-up data are now emerging and indicate that these procedures can offer long-term control of symptoms with few permanent side effects.     

ANCA testing. New developments and clinical implications

Upregulation of keratinocyte-derived VEGF-A expression has recently been established in non-neoplastic processes of skin such as wound healing, blistering diseases and psoriasis, as well as in skin neoplasia. To further characterize the effects of VEGF-A in skin in vivo, we have developed transgenic mice expressing the mouse VEGF120 under the control of a 2.4 kb 5' fragment of keratin K6 gene regulatory sequences that confers transgene inducibility upon hyperproliferative stimuli. As expected from the inducible nature of the transgene, two of the three founder mice obtained (V27 and V208), showed no apparent phenotype. However, one founder (V2), mosaic for transgene integration, developed scattered red spots throughout the skin at birth. The transgenic offspring derived from this founder developed a striking phenotype characterized by swelling and erythema, resulting in early postnatal lethality. Histological examination of the skin of these transgenics demonstrated highly increased vascularization and edema leading to disruption of skin architecture. Expression of the transgene was silent in adult animals of lines derived from founders V27 and V208. Phorbol ester-induced hyperplasia resulted in transgene induction and increased cutaneous vascularization in adult transgenic mice of these lines. Skin carcinogenesis experiments performed on hemizygous crosses of V208 mice with activated H-ras-carrying transgenic mice (TG.AC) resulted in accelerated papilloma development and increased tumor burden. Previous results from our laboratory showed that VEGF upregulation is a major angiogenic stimulus in mouse epidermal carcinogenesis. By overexpressing VEGF in the skin of transgenic mice we now move a step further toward showing that VEGF-mediated angiogenesis is a rate-limiting step in the genesis of premalignant lesions, such as mouse skin papilloma. Our transgenic mice constitute an interesting model system for in vivo study of the cutaneous angiogenic process and its relevance in tumorigenesis and other skin diseases.     

Genetic and biochemical analyses of Actinobacillus pleuropneumoniae urease

The urease gene cluster from the virulent Actinobacillus pleuropneumoniae serotype 1 strain CM5 was cloned and sequenced. The urease activity was associated with a 6.3-kbp region which contains eight long open reading frames (ORFs). The structural genes, ureABC, are separated from the accessory genes, ureEFGD, by a 615-bp ORF of unknown function, ureX. Homologies were found with the structural and accessory urease gene products of Haemophilus influenzae and, to a lesser extent, with those of other organisms. The urease enzyme subunits had predicted molecular masses of 61.0, 11.3, and 11.0 kDa, and the size of the holoenzyme was estimated to be 337 +/- 13 kDa by gel filtration chromatography. Urease activity was maximal but unstable at 65 degrees C. In cell lysates, the A. pleuropneumoniae urease was stable over a broad pH range (5.0 to 10.6) and the optimal pH for activity was 7.7. The Km was 1.5 +/- 0.1 mM urea when it was assayed at pH 7.7. The low Km suggests that this enzyme would be active in the respiratory tract environment, where urea levels should be similar to those normally found in pig serum (2 to 7 mM).     

Genetic and biochemical screening for endocrine disease: II. Ethical issues

The ability to test for specific genes conferring susceptibility to a variety of diseases has profound ethical implications for the way in which we care for patients. Legislators and health care insurers are scrambling to address the aspects of genetic screening that they believe fall within their purview. Critical to the development of appropriate societal regulations regarding genetic screening is a fundamental understanding of the ethical issues involved. A review of those concerns and the areas in which they interface with legal and insurance issues is the topic of this paper.     

Enzymatic differentiation and biochemical and serological characteristics of the clinical isolates of Streptococcus angiosus, S. intermedius and S. constellatus

Of the 29 'Streptococcus milleri' strains tested, all thirteen Streptococcus intermedius (DNA homology group 2) strains but none of the thirteen Streptococcus anginosus (group 1) strains produced beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase, alpha-N-acetylneuraminidase, beta-galactosidase, alpha-glucosidase, and hyaluronidase. The three Streptococcus constellatus (group 3) strains produced only the latter two. Glycosidase production divided 274 clinical isolates into 103 S. anginosus, 101 S. intermedius, and 70 S. constellatus strains. Generally, strains of S. anginosus and S. intermedius were non-beta-haemolytic. API II and biotype Ia (lactose positive), but the former contained almost all API III strains and belonged to Lancefield group A/serotype a (A/a), -/b, C/c, -/d, -/e, F/f or G/k, and the latter included most of biotype IId (lactose negative) and serovar -/g, -/h, -/i or -/j. S constellatus strains were beta-, alpha- or gamma-haemolytic, of API I or II but mostly biotype Ib (lactose negative), and of F/- or -/b. S. intermedius was a major member of the oral isolates. Non-oral isolates were virtually all S. anginosus (mainly urogenital isolates) or S. constellatus (the other systemic isolates).     

Genetic control of mitosis, meiosis and cellular differentiation during mammalian spermatogenesis

Gametogenesis in both the male and female mammal represents a specialized and highly regulated series of cell cycle events, involving both mitosis and meiosis as well as subsequent differentiation. Recent advances in our understanding of the genetic control of the eukaryotic cell cycle have underscored the evolutionarily-conserved nature of these regulatory processes. However, most of the data have been obtained from yeast model systems and mammalian cell lines. Furthermore, most of the observations focus on regulation of mitotic cell cycles. In the present paper: (i) aspects of gametogenesis in mammals that represent unique cell-cycle control points are highlighted; (ii) current knowledge on the regulation of the germ cell cycle, in the context of what is known in yeast and other model eukaryotic systems, is summarized; and (iii) strategies that can be used to identify additional cell cycle regulating genes are outlined.     

Genetic and biochemical screening for endocrine disease: III. Costs and logistics

To clarify the regulatory mechanism of the production of various inflammatory mediators by intestinal epithelial cells, the effect of bile acids (tauroursodeoxycholate, TUDC; taurochenodeoxycholate, TCDC; and taurocholate, TC) on the cytokine-induced production of interleukin (IL)-8 in a human colon epithelial cell line (HT-29) was examined. HT-29 cells were incubated for 24 h in a culture medium containing tumour necrosis factor alpha (TNF alpha; 1 ng/mL) and/or interleukin (IL)-1beta (1 ng/mL) in the presence or absence of bile acids. The IL-8 concentration in the medium was measured by an enzyme-linked immunosorbent assay. The binding assay of TNF alpha was performed using [125I]-TNF alpha (100 pmol/L). Interleukin-8 production during incubation with TNF alpha was markedly reduced in the presence of 0.5 and 1 mmol/LTUDC, 0.5 and 1 mmol/LTCDC and 0.5 and 1 mmol/LTC, by 56, 85, 86, 91, 37 and 70%, respectively. The IL-8 production during incubation with IL-1beta was not significantly reduced in the presence of these bile acids. The specific binding of TNF alpha to cells was inhibited 33, 47, and 14% by 1 mmol/LTUDC, TCDC and TC, respectively. These findings suggest that bile acids inhibit TNF alpha-induced IL-8 production by the colonic cells. The suppression may be partly due to inhibition of TNF alpha binding to the cells by bile acids.     

Autosomal dominant striatonigral degeneration. A clinical, pathologic, and biochemical study of a new genetic disorder

An autosomal dominant striatonigral degeneration is present in a family of Portuguese ancestry numbering in excess of 329 persons in eight generations. The illness begins in the second, third, or fourth decade, and progresses for about 15 years with parkinsonian rigidity, spasticity, spastic dysarthria, and abnormalities of eye movement. Neuropathologic findings are severe neuronal loss and astrocytic gliosis in the corpus striatum and substantia nigra, with a moderate neuronal loss in the dentate nucleus of the cerebellum and nucleus ruber of the midbrain. This is a new genetic entity, distinct from other autosomal dominant neurologic disorders such as nigrospinodentatal degeneration, olivopontocerebellar degeneration, dystonia musculorum deformans, Machado's disease, and Huntington's disease.     

Human mucopolysaccharidosis IIID: clinical, biochemical, morphological and immunohistochemical characteristics

Mucopolysaccharidosis IIID (MPS IIID) is one of the rarest of the MPS-III syndromes. To date, the clinical manifestations of 10 patients have been reported, the deficient N-acetylglucosamine 6-sulfatase (G6S) enzyme has been purified, and the G6S gene has been cloned, sequenced and localized. However, morphological manifestations of this condition have not been reported and the pathogenesis of the severe neurological deficits remains an enigma. In this paper we describe and correlate the clinical, biochemical and pathological observations for 2 cases of MPS IIID. We used monoclonal antibodies against heparan sulfate (HS) and GM2-ganglioside, thin layer chromatography, mass spectrometry, and morphological techniques to demonstrate the nature and the distribution of the uncatabolized substrates. The majority of the cells in various tissues showed morphological changes expected with lysosomal storage of HS. The central nervous system (CNS) was most severely affected because of the secondary storage of GM2 and GM3 gangliosides in addition to the primary accumulation of HS. The extent as well as the distribution of the diverse storage materials varied within and among different neurons as observed in MPS-III A, B, and C syndromes. This study supports the hypothesis that the neurological dysfunction and neurodegeneration common to the Sanfilippo syndromes is, in part, due to the secondary metabolic perturbations induced by HS accumulation.     

The fish odour syndrome: biochemical, familial, and clinical aspects

OBJECTIVES: To study the biochemical, familial, and clinical features of the fish odour syndrome among subjects with suspected body malodour. DESIGN: Subjects who responded to a newspaper article were screened for the fish odour syndrome by interview and biochemical tests. Families of subjects with the syndrome were tested if possible. SETTING: St Mary's Hospital, London, and some interviews at subjects' homes. SUBJECTS: 187 subjects (28 males) with suspected body malodour, of whom 156 (19 males) underwent biochemical tests. Five families of six of the subjects with the fish odour syndrome agreed to further tests. MAIN OUTCOME MEASURES: Amounts of trimethylamine and trimethylamine N-oxide in urine collected over 24 hours under normal dietary conditions and for eight hours after oral challenge with 600 mg trimethylamine. RESULTS: The fish odour syndrome was diagnosed in 11 subjects: the percentage of total trimethylamine excreted in their urine samples that was oxidised to trimethylamine N-oxide was < 55% under normal dietary conditions and < 25% after oral challenge with trimethylamine (in normal subjects > 80% of trimethylamine was N-oxidised). Parents of six of the subjects with the syndrome were tested: all showed impaired N-oxidation of excreted trimethylamine (< 80%) after oral challenge, indicating that they were heterozygous carriers of the allele for the syndrome. The syndrome was associated with various psychosocial reactions including clinical depression. CONCLUSIONS: The fish odour syndrome can be inherited in an autosomal recessive fashion. It should be considered as a possible causative factor in patients complaining of body malodour.     

Children's understanding of adoption: Developmental and clinical implications.

Because adopted children are overrepresented in mental health settings, their parents often consult psychologists to help them understand and manage some of the unique developmental and childrearing challenges they commonly face. One of the most frequent issues raised by these parents is talking with their children about adoption. This article provides a developmental framework for helping psychologists understand the way children comprehend adoption and the implications of their adoption knowledge for psychological adjustment. It also provides psychologists with useful guidelines for supporting parents to meet the challenges of discussing adoption with their children. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

An overview of clinical policies with implications for clinical practice, medical education, and research

Clinical policies, also known as practice parameters or practice guidelines, are gaining notoriety out of a desire to control escalating medical costs, lessen wide practice variations, and improve quality of care. The clinical policies are supposed to influence medical decision making by summarizing scientific data about a clinical problem in a format that is easily understood by patient and physician alike. Developing an evidence-based policy involves: a clearly defined clinical problem, a comprehensive literature review, a summary table of the data (known as an evidence table), a presentation of this data as outcome possibilities from alternative decisions (in the form of a balance sheet), and creation of clinical recommendations that incorporate both financial costs and patient preferences. Well-developed policies can be used by family physicians as guides in areas of clinical uncertainty and by medical educators as up-to-date literature syntheses for teaching critical appraisal and for outlining approaches to common problems. Explicit policy formulation also highlights the shortcomings of existing literature and can suggest more appropriate future research. The future of the clinical policy movement rests on its ability to reduce costs of care and improve patient outcomes. Explicit clinical policy formulation incurs significant development and implementation costs and the evidence on which many policies are based is lacking. Nevertheless, clinical policies in some form are likely to play an increasing role in medical care.     

Finding the self: A behavioral measure and its clinical implications.

Presents a clinical model of the development of self. The model focuses on the early learning responsible for linguistic self-referents such as "I" and "me." This model offers an account for why some patients, such as those with borderline personality disorder (BPD), feel that they "do not know who they are" or that their sense of self is controlled by other people, while other patients have a sense of a secure, stable self that is not prey to the whims of others. The authors administered the Experiencing of Self Scale, which measures the degree to which other people influence the experience of self, along with the Self-Esteem Scale and the Dissociative Experiences Scale to 284 undergraduate students (mean age 19.2 yrs) and 14 BPD patients (mean age 41.1 yrs). Results show that the degree to which other people influence the experience of self depended on the nature and closeness of the people involved, that those in the BPD sample suffered from excessive influence of other people over the experience of self relative to the undergraduates, and that the degree of influence correlated predictably with high dissociation and low self-esteem. Implications for conceptualizing BPD and narcissistic personality disorder are discussed, and clinical applications are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)