D4F104S1 deletion in facioscapulohumeral muscular dystrophy: phenotype, size, and detection

BACKGROUND

The facioscapulohumeral muscular dystrophy (FSHD) locus maps to 4q35 where it is closely linked to D4F104S1 (p13E-11), a probe that recognizes the pathognomonic FSHD deletion involving the subtelomeric D4Z4 tandem repeat array. Extended deletions that include both the more proximal D4F104S1 region and the D4Z4 repeat array proper do, however, occur, albeit rarely, and such deletions can lead to difficulties of interpretation in the diagnostic setting.

OBJECTIVE

To devise a means to determine the true frequency of proximally extended deletions in individuals with FSHD.

METHODS

Three families selected for this study were originally identified during routine FSHD analysis on the basis that the affected individuals in each family had failed to exhibit a small (<38-kb) EcoRI fragment. High molecular weight DNA from these families was analyzed with both conventional and pulsed-field gel electrophoresis using DNA markers p13E-11, 9B6A, B31, 4qA, and 4qB.

RESULTS

Large genomic deletions were identified involving both D4Z4 and D4F104S1. The precise number of D4Z4 repeat units borne by the p13E11 deletion allele was established by the use of an additional restriction enzyme (MseI) digest. All three cases carry different sizes of deletion proximal to the D4Z4 repeat units. With use of a recently described telomeric probe, 4qA, a method was developed that identifies large genomic deletions involving both D4Z4 and D4F104S1 using conventional gel electrophoresis.

CONCLUSION

Proximally extended deletions can be found in patients with a normal spectrum of the disease. This assay promises to allow estimation of the true frequency of proximally extended deletions and should improve the accuracy and reliability of molecular diagnostic testing for FSHD.

Cofactor processing in galactose oxidase

Galactose oxidase (GO; EC 1.1.3.9) is a monomeric 68 kDa enzyme that contains a single copper and an amino acid-derived cofactor. The mechanism of this radical enzyme has been widely studied by structural, spectroscopic, kinetic and mutational approaches and there is a reasonable understanding of the catalytic mechanism and activation by oxidation to generate the radical cofactor that resides on Tyr-272, one of the copper ligands. Biogenesis of this cofactor involves the post-translational, autocatalytic formation of a thioether cross-link between the active-site residues Cys-228 and Tyr-272. This process is closely linked to a peptide bond cleavage event that releases the N-terminal 17-amino-acid pro-peptide. We have shown using pro-enzyme purified in copper-free conditions that mature oxidized GO can be formed by an autocatalytic process upon addition of copper and oxygen. Structural comparison of pro-GO (GO with the prosequence present) with mature GO reveals overall structural similarity, but with some regions showing significant local differences in main chain position and some active-site-residue side chains differing significantly from their mature enzyme positions. These structural effects of the pro-peptide suggest that it may act as an intramolecular chaperone to provide an open active-site structure conducive to copper binding and chemistry associated with cofactor formation. Various models can be proposed to account for the formation of the thioether bond and oxidation to the radical state; however, the mechanism of prosequence cleavage remains unclear.

Early detection of PrPres in BSE-infected bovine PrP transgenic mice

Transgenic mouse lines expressing different levels of the bovine prion protein gene (boPrP(C)) were generated. Upon infection with BSE prions, all transgenic lines tested exhibited characteristics of the bovine disease. Typical CNS spongiform degeneration was observed by histopathology and presence of PrP(res) could be detected both by Western blot and immunohistochemistry (IHC) assays, confirming for this model the absence of an interspecies barrier to BSE infection. Differences in incubation times post-inoculation depend upon the expression level of boPrP(C) and the amount of prions in the inoculum. In the absence of clinical signs, pathognomonic markers of disease could be detected as early as 150 or 196 days post-inoculation by IHC and Western blot analysis, respectively. This result indicates that prion infectivity in experimental mouse bioassays can be measured earlier by assessing immunologically the presence of PrP(res) in brains from inoculated animals. Although these transgenic mice were also susceptible to sheep scrapie prion infection, the extent of incubation times was considerably longer and PrP(res) was detected in only 70 % of inoculated mice. Interestingly, transgenic mice-propagated sheep scrapie prions displayed distinct biochemical properties when compared to both the original sheep scrapie and transgenic mouse-propagated BSE inoculum.

Expression of RANKL and OPG mRNA in periodontal disease: possible involvement in bone destruction

Periodontitis is a complex, multifactorial process affected by bacterial plaque-components and host defense mechanisms. Inflammation of the periodontitium may lead the destruction of the underlying ligament and alveolar bone. Receptor activator of NF-kappaB ligand (RANKL), a novel TNF receptor-related protein is an important factor for osteoclast differentiation and activation. Given osteolysis by osteoclast has been demonstrated in periodontitis, we hypothesized that RANKL expression may be associated with bone destruction in periodontitis. We used semi-quantitative RT-PCR to compare the gene expression of RANKL and osteoprogerin (OPG), a decoy receptor of RANKL, between moderate and advanced periodontitis, and healthy subjects. The level of RANKL mRNA was highest in advanced periodontitis. In contrast, the level of OPG mRNA in both advanced and moderate periodontitis was lower than that in the healthy group. It appears that the ratio of RANKL to OPG mRNA in periodontitis has increased. To determine the localization of RANKL gene transcripts in gingival tissue at the cellular level, in situ hybridization was performed using digoxigenin-labeled specific riboprobes. RANKL mRNA was expressed in inflammatory cells, mainly lymphocyte and macrophages. In addition, proliferating epithelium in the vicinity of inflammatory cells expressed high levels of RANKL mRNA. In short, our data suggest that up regulation of RANKL mRNA in both inflammatory cells and epithelium may be associated with the activation of osteoclastic bone destruction in periodontitis.

Metallothionein in bovine spongiform encephalopathy

An increase in metallothionein I and II (MT I/II) mRNA concentrations has been reported in the central nervous system of scrapie-infected rodents. In this study we compared cattle with bovine spongiform encephalopathy (BSE), cattle affected by neurological disease other than BSE, and clinically healthy cattle in respect of MT I/II immunoreactivity in brainstem medullary tissue. Marked astrocytic MT I/II immunolabelling was seen in all BSE-affected animals, in contrast to clinically healthy cases, in which no such labelling was detected. In BSE, MT I/II immunoreactive astrocytes were confined specifically to areas of vacuolation or abnormal prion protein (PrP(BSE)) deposition, or both. MT I/II immunolabelling was also seen in a small number of animals with a neurological disease other than BSE. These findings complement previous studies by demonstrating increased levels of MT I/II in transmissible spongiform encephalopathy (TSE)-infected brain tissue, indicating that MT I/II may play some as yet unidentified role in the response to TSE infection.

A control model of the movement of attention

A control model of the movement of the focus of attention is developed and applied to explain its observed effects on single cell activity and to various quantitative features of the Posner benefit paradigm. This supports the presence of an inverse controller and a rules component in the control model. The ability of the control model to explain a range of deficits is then analyzed, as is its relation to other modeling approaches.

Evaluation of the Mycobacterium bovis restriction fragment length polymorphism probe pUCD, in combination with the direct repeat probe, for molecular typing of Mycobacterium tuberculosis strains in Ireland

A mycobacterial restriction fragment length polymorphism probe, pUCD, has recently been described which represents an effective tool for the strain typing of Mycobacterium bovis. The present study evaluated this probe, in combination with the direct repeat probe (DR), for the molecular typing of 90 strains of Mycobacterium tuberculosis from 87 patients, looking at a group (62 isolates) of nonselected samples to assess pUCD combined with DR as a general tool and a subset of 32 isolates with a common specific IS6110 strain type in Ireland. Within the group of 62 isolates, pUCD-DR identified 42 strains and was comparable to both IS6110 (41 strains) and polymorphic guanine-cytosine-rich sequence (PGRS) (37 strains) analysis. pUCD-DR was found to be comparable to IS6110 and PGRS in identifying four separate clusters of isolates which were confirmed to be clinically related. pUCD-DR divided the common IS6110 isolates into six distinct types and was comparable to PGRS (seven strain types). The usefulness of this probe as an epidemiological tool is discussed.

[Epidemiology of apparently benign ovarian cysts]

The incidence of ovarian cysts in the general population is difficult to estimate. Certain cysts are functional and generally not operated, except in case of complications. Others are organic cysts which are usually, but not always operated. Data is available only from surgical series or pathology reports. An analysis of the literature shows that for operated cysts, approximately 75% are organic, 25% are function and 1 to 4% of the supposed benign cysts are found to be malignant. In France, the PMSI database on public and private institutions is available on the net (www.le-pmsi.fr). The number of hospital stays for benign ovarian tumors or ovarian cysts was to the order of 45,000 in 1998 and 1999. Twenty-one percent of these patients were discharged without surgery. Most had a functional cyst of the ovary. This leaves 32,000 women who underwent surgery annually for an ovarian cyst. Nearly 7000 women were hospitalized for follicular or yellow body cysts, i.e. 15%, with an incidence of 29/100,000 women over the age of 15 years. The abstention rate for hospitalized women with a follicular cyst or a yellow body cyst was 30 to 40%. For endometrioma, there were 5218 hospitalizations in 1999 (2137 in the public hospitals and 3081 in private clinics) (11% of the hospitalizations). The rate of abstention was 11% (15% in the public hospitals and 8% in private clinics). Approximately 4100 women thus underwent surgery, including 13% for ovarian cysts. According to data in the literature, serous and mucinous cysts account for 20 to 30% of the operated cysts and dermoid cysts for 10 to 20%. The type of cyst cannot be identified with the international WHO classification used in the PMSI.

Inflammatory linear verrucous epidermal naevi: a review of 23 cases

Twenty-three patients diagnosed with inflammatory linear verrucous epidermal naevi (ILVEN) over a 13 year period are reviewed retrospectively. These ILVEN showed a predilection for the buttock and legs and were usually unilateral. Onset of the lesions was usually within the first 6 months of life and extension beyond the original margins occurred in 26% of cases. Sixteen of the 23 patients were male. Ten patients had ILVEN predominantly involving the left side, 12 were on the right side and, in one case, the side involved was not recorded.

Artefactual skin disease in children and adolescents

As in adults, artefactual skin disease in children and adolescents has heterogenous presentations with multifactorial aetiology. We report a series of 32 young patients aged 8-16 years. There were 24 females and 8 males. In over half of the cases the lesions were on the head and neck. The types of lesions encountered included physical injury producing grazing, erosions and deep ulcers, chemical and thermal burns, hair cutting and shaving and skin painting. We discuss the approach that we believe should be taken with these patients, emphasizing the role of dermatology-psychiatry liaison in their management. Of great importance is the avoidance of confrontation of the patient but the clear exposition of the nature of the problem to the parents. The major aim should be to have the family accept the need for expert psychiatric assistance.

Keratin 14 point mutations at codon 119 of helix 1A resulting in different epidermolysis bullosa simplex phenotypes

Epidermolysis bullosa simplex is a heterogeneous group of inherited bullous disorders due to mutations in keratins 5 and 14. We report two different mutations in keratin 14 at codon 119 of the helix initiation peptide, each with different phenotypic expression. One, a sporadic case that clinically resembles Dowling-Meara epidermolysis bullosa simplex, resulted from conversion of methionine to threonine (M119T). The other, a multigeneration family with the Koebner phenotype, resulted from a previously unreported methionine to valine substitution (M119V). We suggest that loss of hydrophobicity during conversion of methionine to threonine is responsible for the more severe presentation of the first family, whereas maintenance of the hydrophobic nature of the amino acid with conversion to valine resulted in a less severe variant of epidermolysis bullosa simplex. Although most prior mutations in the highly conserved boundary motif of the alpha-helix have resulted in the Dowling-Meara subtype, our findings confirm that it is not always possible to predict the epidermolysis bullosa simplex severity on the basis of the location of the mutation along the keratin polypeptide. The specific amino acid substitution may be more critical in some cases.

HeartCare: an Internet-based information and support system for patient home recovery after coronary artery bypass graft (CABG) surgery

HeartCare is an Internet-based information and support service for patients recovering at home from coronary artery bypass graft (CABG) surgery. The system is designed to meet the nursing challenges in health information to support needs of CABG patients. HeartCare (a) provides information and support, tailored to patients' individual and changing recovery needs during CABG recovery, (b) makes recovery information more accessible for timely use by patients, and (c) extends the scope of nursing services to CABG patients from hospital through home. An ongoing randomized controlled study is underway to evaluate the clinical outcomes of patients' use of the HeartCare system and to examine its acceptance as a usable resource for postCABG patients who have limited previous computer experience.

Human immunodeficiency virus type 1 DNA sequences genetically damaged by hypermutation are often abundant in patient peripheral blood mononuclear cells and may be generated during near-simultaneous infection and activation of CD4(+) T cells

G-to-A hypermutation has been sporadically observed in human immunodeficiency virus type 1 (HIV-1) proviral sequences from patient peripheral blood mononuclear cells (PBMC) and virus cultures but has not been systematically evaluated. PCR primers matched to normal and hypermutated sequences were used in conjunction with an agarose gel electrophoresis system incorporating an AT-binding dye to visualize, separate, clone, and sequence hypermutated and normal sequences in the 297-bp HIV-1 protease gene amplified from patient PBMC. Among 53 patients, including individuals infected with subtypes A through D and at different clinical stages, at least 43% of patients harbored abundant hypermutated, along with normal, protease genes. In 70 hypermutated sequences, saturation of G residues in the GA or GG dinucleotide context ranged from 20 to 94%. Levels of other mutants were not elevated, and G-to-A replacement was entirely restricted to GA or GG, and not GC or GT, dinucleotides. Sixty-nine of 70 hypermutated and 3 of 149 normal sequences had in-frame stop codons. To investigate the conditions under which hypermutation occurs in cell cultures, purified CD4(+) T cells from normal donors were infected with cloned NL4-3 virus stocks at various times before and after phytohemagglutinin (PHA) activation. Hypermutation was pronounced when HIV-1 infection occurred simultaneously with, or a few hours after, PHA activation, but after 12 h or more after PHA activation, most HIV-1 sequences were normal. Hypermutated sequences generated in culture corresponded exactly in all parameters to those obtained from patient PBMC. Near-simultaneous activation and infection of CD4(+) T cells may represent a window of susceptibility where the informational content of HIV-1 sequences is lost due to hypermutation.

Uncertainty and opposition of medical students toward assisted death practices

To explore medical students' views of assisted death practices in patient cases that describe different degrees and types of physical and mental suffering, an anonymous survey was administered to all students at one medical school. Respondents were asked about the acceptability of assisted death activities in five patient vignettes and withdrawal of life support in a sixth vignette. In the vignettes, actions were performed by four possible agents: the medical student personally; a referral physician; physicians in general; or non-physicians. Of 306 medical students, 166 (54%) participated. Respondents expressed opposition or uncertainty about assisted death practices in the five patient cases that illustrated severe forms of suffering which were secondary to amyotrophic lateral sclerosis, treatment-resistant depressive and somatoform disorders, antisocial and sexually violent behavior, or AIDS. Students supported the withdrawal of life support in the sixth vignette depicting exceptional futility secondary to AIDS. Students were especially opposed to their own involvement and to the participation of non-physicians in assisted death activities. Differences in views related to sex, religious beliefs, and personal philosophy were found. Medical students do not embrace assisted death practices, although they exhibit tolerance regarding the choices of medical colleagues. How these attributes of medical students will translate into future behaviors toward patients and peers remains uncertain. Medical educators must strive to understand the perspectives of physicians-in-training. Expanded, empirically informed education that is attuned to the attitudes of medical students may be helpful in fulfilling the responsibility of imparting optimal clinical care skills.

Cholera toxin-induced PGE(2) activity is reduced by chemical reaction with L-histidine

Mediators of cholera toxin (CT)-induced fluid secretion include 3',5'-adenosine monophosphate (cAMP), prostaglandin E(2) (PGE(2)), and 5-hydroxytryptamine (5-HT). Administration of L-histidine significantly reduced the net secretory response of the small intestine of mice challenged with CT and reduced the capacity of PGE(2) to stimulate Na+ transport in Ussing chambers. We demonstrated that L-histidine chemically modified the structure of PGE(2) but had no direct effect on cAMP or 5-HT. L-Histidine and imidazole reacted with PGE(2) in vitro in cell-free mixtures incubated at 37 degrees C and pH 7.0 under an atmosphere of N(2) with the formation of PGE(2)-imidazole and PGE(2)-histidine covalent adducts. Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) analysis of the purified adduct showed that imidazole catalyzed the dehydration of PGE(2). A Michael adduct then was formed between C11 of 11-deoxy-Delta(10) PGE(2) (PGA(2)) and the tau nitrogen in the imidazole ring of L-histidine. Importantly, the isolated PGE(2)-imidazole and PGE(2)-histidine adducts inhibited CT-induced fluid loss and cAMP accumulation in mouse intestinal loops. The protection provided by PGE(2)-imidazole, PGE(2)-histidine, and L-histidine against intestinal fluid loss could provide a basis for future therapy against cholera.

Clinical manifestations in a cohort of 41 Rothmund-Thomson syndrome patients

Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive genodermatosis characterized by a poikilodermatous rash starting in infancy, small stature, skeletal abnormalities, juvenile cataracts, and predisposition to specific cancers. We have identified a contemporary cohort of 41 patients to better define the clinical profile, diagnostic criteria, and management of patients with RTS. Patients with the diagnosis of RTS were ascertained by referrals from dermatology, ophthalmology, genetics, and oncology or from direct contact with the patient's family. Medical information was obtained from interviews with physicians, patients, and their parents and a review of medical records. The age range at ascertainment was 9 months to 42 years (28 males and 13 females; M:F, 2:1). All subjects displayed a characteristic rash. Thirteen subjects had osteosarcoma (OS) (32%), eight had radial defects (20%), seven had gastrointestinal findings (17%), two had cataracts (6%), and one had skin cancer (2%). Twenty-two of 28 patients without OS were less than 15 years old and thus remain at significant risk for this tumor. This case-series study reveals a clinical profile of RTS that includes a higher prevalence of OS and fewer cataracts, compared with historical reports. These differences may reflect either allelic or genetic heterogeneity. This study documents the frequency of clinical anomalies in a contemporary cohort of RTS patients and revises guidelines for diagnosis and management of RTS.

Donor scoring system for cadaveric renal transplantation

We studied early renal function in 241 consecutive patients who received cadaveric renal transplants at two different transplantation centers (group 1, n = 90; group 2, n = 151). Univariate and multivariate analyses of data from group 1 showed a significant correlation between seven donor variables and early renal function after cadaveric renal transplantation. A scoring system was developed from these seven donor variables (cause of death, 0-6 points; history of hypertension, 0-6; final creatinine clearance before procurement, 0-6; age, 0-6; history of diabetes mellitus, 0-3; cold ischemia time, 0-3; and severity of renal artery plaque, 0-3). Data from group 2 were used to validate the donor scoring system and stratify cadaver kidneys on the basis of score: grade A, 0-5 points; grade B, 6-10; grade C, 11-15; and grade D, 16-32. A significant decline in early renal function was observed with increasing donor score and grade of cadaver kidney. In conclusion, a donor scoring system based on information available at the time of procurement can be used to estimate early graft function after cadaveric renal transplantation and may assist in the allocation of marginal organs.

In situ hybridization to cellular RNA

In situ hybridization to cellular RNA is used to determine the cellular localization of specific messages within complex cell populations and tissues. Tissues may either be embedded in paraffin and sectioned on a microtome (see Hybridization Using Paraffin Sections and Cells), or frozen and sectioned in a cryostat (see Hybridization Using Cryosections). RNA contained in the specimens is hybridized to a specific radiolabeled probe (see Synthesis of (35)S-Labled Riboprobes and Synthesis of (35)S-Labled Double-Stranded DNA Probes), which is then detected using film autoradiography or emulsion autoradiography (Chapter 8).

Childhood psoriasis: a clinical review of 1262 cases

Our aim was to describe the types of psoriasis seen in a large series of patients presenting to a tertiary referral pediatric dermatology department using a classification system combining conventional terminology and additional categories based on the site and characteristics of the rash. A total of 1262 patients seen consecutively in the dermatology department of the Royal Alexandra Hospital for Children, Sydney, Australia, between 1981 and 1995 are described and classified according to the pattern of psoriasis at the time of presentation. Additional information recorded included family history, facial involvement, and history of a psoriatic type of diaper rash in infancy. The ages of the children ranged from 1 month to 15 years. There was an equal gender distribution and a high rate of positive family history at 71%. Twenty-six percent of children had a history of a psoriatic diaper rash and facial involvement occurred in 38% of children. Plaque psoriasis was the most common type overall, affecting 430 patients (34%). Three hundred forty-five children were less than 2 years of age, and this is the largest series of children with psoriasis in this age group presented to date. An entity defined by us as psoriatic diaper rash with dissemination was the most common type of psoriasis in the less than 2-year age group, affecting 155 (45%) patients. This large series offers information on the manifestations of psoriasis in childhood, but is particularly useful in examining the previously less well-described infant age group. The classification used is proposed as a practical way to describe psoriasis in children, particularly with respect to future descriptive studies.

Multiple lifestyle and psychosocial risks and delivery of small for gestational age infants

OBJECTIVE

To examine the occurrence of multiple risk behaviors during pregnancy among women who delivered a live birth and to examine the risk of delivering small for gestational age (SGA) infants for women with multiple risks.

METHODS

We used data from the Pregnancy Risk Assessment Monitoring System to conduct the research. Pregnancy Risk Assessment System is a population-based, mixed-mode surveillance system that collects information on maternal behaviors and experiences. We used data for 1997 from 13 (n = 19,331) states that had response rates of over 70%. We considered ten self-reported individual risk behaviors or exposures (eg, smoking, unintended pregnancy) and several demographic variables. The main outcome was SGA.

RESULTS

Pregnant women engage in or are exposed to multiple risks and often these risks are inter-related. The occurrence of multiple risks appears to be associated with an increased likelihood of delivering an SGA infant. Compared with women with no reported risks or exposures, the adjusted odds ratios for delivering an SGA infant were as follows: 1.29 (95% confidence interval [CI] 0.69, 2.43) for one, 1.86 (95% CI 1.00, 3.44) for two, 1.67 (95% CI 0.90, 3.10) for three, 2.06 (95% CI 1.10, 3.89) for four, 3.53 (95% CI 1.71, 7.30) for five, and 3.82 (95% CI 1.97, 7.41) for six or more risks or exposures.

CONCLUSION

A large proportion of pregnant women engage in or are exposed to multiple risks. Women with a larger number of risks are at greater risk for delivering an SGA infant than women with fewer or no risks.