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Biomedical subjects

M C Jones

Publications and source records attributed to M C Jones.

At least 37 records · Page 2Linked to original sources
PubMed1999

Monodactylous limbs and abnormal genitalia are associated with hemizygosity for the human 2q31 region that includes the HOXD cluster.

Vertebrates have four clusters of Hox genes (HoxA, HoxB, HoxC, and HoxD). A variety of expression and mutation studies indicate that posterior members of the HoxA and HoxD clusters play an important role in vertebrate limb development. In humans, mutations in HOXD13 have been associated with type II syndactyly or synpolydactyly, and, in HOXA13, with hand-foot-genital syndrome. We have investigated two unrelated children with a previously unreported pattern of severe developmental defects on the anterior-posterior (a-p) limb axis and in the genitalia, consisting of a single bone in the zeugopod, either monodactyly or oligodactyly in the autopod of all four limbs, and penoscrotal hypoplasia. Both children are heterozygous for a deletion that eliminates at least eight (HOXD3-HOXD13) of the nine genes in the HOXD cluster. We propose that the patients' phenotypes are due in part to haploinsufficiency for HOXD-cluster genes. This hypothesis is supported by the expression patterns of these genes in early vertebrate embryos. However, the involvement of additional genes in the region could explain the discordance, in severity, between these human phenotypes and the milder, non-polarized phenotypes present in mice hemizygous for HoxD cluster genes. These cases represent the first reported examples of deficiencies for an entire Hox cluster in vertebrates and suggest that the diploid dose of human HOXD genes is crucial for normal growth and patterning of the limbs along the anterior-posterior axis.

Child, Preschool↗
PubMed1998

Correlation of linkage data with phenotype in eight families with Stickler syndrome.

The clinical findings of eight families with Stickler syndrome were analyzed and compared with the results of linkage studies using a marker for the type II collagen gene (COL2A1). In six families, there was linkage of the phenotype to COL2A1. The manifestations of the affected individuals were similar to those of the original Stickler syndrome family [Stickler et al., Mayo. Clin. Proc. 40:433-455, 1965] and resembled the phenotype of the previously reported individuals or families with Stickler syndrome in which a dominant mutation in the COL2A1 gene has been identified. Linkage to COL2A1 was excluded in the two remaining families. The most striking difference between these two types of families was the absence of severe myopia and retinal detachment in the two unliked families. In the COL2A1 unlinked families, linkage of the phenotype to genes (COL11A1 and COL11A2) that encode pro alpha chains of type XI collagen, a minor cartilage-specific collagen, was also excluded. Since Stickler syndrome can be produced by mutations in COL2A1, COL11A1, and COL11A2, our data suggest that there is at least a fourth locus for Stickler syndrome.

Collagen↗
PubMed1998

Absence of PTEN/MMAC1 germ-line mutations in sporadic Bannayan-Riley-Ruvalcaba syndrome.

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare hamartomatous polyposis condition with features of macrocephaly, intestinal juvenile polyposis, developmental delay, lipomas, and pigmentation spots of the male genitalia. An autosomal dominant pattern of inheritance exists in some families, but others appear as sporadic cases. Germ-line mutations in PTEN, a tyrosine phosphatase and putative tumor suppressor gene, have been demonstrated in two families with BRRS, and chromatin loss at the PTEN gene locus on chromosome 10q23 has been demonstrated in two BRRS patients. Germ-line mutations in PTEN have also been described in Cowden disease and in a small number of patients with juvenile polyposis syndrome. In an attempt to assess the nature of PTEN mutations in BRRS, we analyzed three sporadic BRRS patients for chromosome 10q23 deletion or PTEN germ-line mutations. All 3 patients demonstrated no loss of parental alleles at 15 chromosome 10q23 markers that encompassed the region of PTEN. In addition, analysis of mRNA and genomic DNA revealed no nonsense, missense, or insertion/deletion mutations of PTEN. Thus, other mechanisms besides mutation of PTEN must have occurred to cause BRRS in these patients. We speculate that BRRS and juvenile polyposis syndrome may have a heterogeneous etiology to cause their syndromes.

DNA↗
PubMed1998

Impact of Medicaid resources on core public health responsibilities of local health departments in Illinois.

With Illinois' plan to embark on a statewide Medicaid managed care program, the impact of Medicaid resources on core public health responsibilities of local health departments (LHDs) was assessed and found to be substantial. A reduction of $330,000 in core public health activities would likely accompany each $1 million in Medicaid resources lost by these LHDs. Only by actively participating in the planning and implementation of these conversions can public health agencies maintain high productivity and efficiency in addressing core public health responsibilities in their communities.

Budgets↗
PubMed1997

Evaluation of mental retardation: recommendations of a Consensus Conference: American College of Medical Genetics.

A Consensus Conference utilizing available literature and expert opinion sponsored by the American College of Medical Genetics in October 1995 evaluated the rational approach to the individual with mental retardation. Although no uniform protocol replaces individual clinician judgement, the consensus recommendations were as follows: 1. The individual with mental retardation, the family, and medical care providers benefit from a focused clinical and laboratory evaluation aimed at establishing causation and in providing counseling, prognosis, recurrence risks, and guidelines for management. 2. Essential elements of the evaluation include a three-generation pedigree: pre-, peri-, and post-natal history, complete physical examination focused on the presence of minor anomalies, neurologic examination, and assessment of the behavioral phenotype. 3. Selective laboratory testing should, in most patients, include a banded karyotype. Fragile X testing should be strongly considered in both males and females with unexplained mental retardation, especially in the presence of a positive family history, a consistent physical and behavioral phenotype and absence of major structural abnormalities. Metabolic testing should be initialed in the presence of suggestive clinical and physical findings. Neuroimaging should be considered in patients without a known diagnosis especially in the presence of neurologic symptoms, cranial contour abnormalities, microcephaly, or macrocephaly. In most situations MRI is the testing modality of choice. 4. Sequential evaluation of the patient, occasionally over several years, is often necessary for diagnosis, allowing for delineation of the physical and behavioral phenotype, a logical approach to ancillary testing and appropriate prognostic and reproductive counseling.

Diagnosis, Differential↗
PubMed1997

Ring chromosome X in a child with manifestations of Kabuki syndrome.

A female patient with the karyotype 45,X/46, X, r(X)(p11.2 q13) and severe developmental delay, prominent fingertip pads, long palpebral fissures, short stature, and history of hypotonia had a phenotype reminiscent of Kabuki syndrome. We hypothesized that overexpression of X chromosome-derived sequences might be associated with the Kabuki-like phenotype observed. The nature and parental origin of this small-ring X were ascertained using a combination of genotyping with microsatellite markers and quantitative Southern blotting. PCR-based genotyping demonstrated heterozygosity at X-linked loci SBMA (Xq11-q12) and DXS227 (Xq13.1). Hemizygosity was observed at several loci: DMD STR-49 (Xp21.2), DXS1003 (Xp11.23), DXS988 (Xp11.21), DXS101 (Xq21.3), FMR-1 (Xq27.3), and DXYS64 (Xq28). This ring X chromosome is paternally derived since only maternal alleles are inherited at three informative microsatellite loci. Results of FISH and RT-PCR experiments indicate that the XIST locus is missing in the ring X chromosome and not expressed. These data indicated a large deletion of the X chromosome consistent with a small-ring X chromosome with approximate breakpoints near p11.2 and q13. These results are comparable to the observation of others where an atypically severe phenotype has been associated with the presence of an r(X), or small mar(X).

Abnormalities, Multiple↗
PubMed1997

Trauma-related symptomatology among American Indian adolescents.

The Diagnostic Interview Schedule for Children (DISC-2.1C), including the postraumatic stress disorder (PTSD) module, was administered to 109 American Indian adolescents from a Northern Plains reservation. In response to the DISC's open-ended probes, 61% of respondents reported at least one traumatic event. Despite high rates of trauma and substantial numbers of subsyndromal PTSD symptoms, the prevalence rate of diagnosable PTSD was found to be only 3%. The reporting of traumatic events was associated with increased prevalence of behavioral disorders and substance abuse or dependence diagnoses. There was, however, no significant difference in academic performance (grade point average or scholastic aptitude test scores) between those who reported traumatic events, or PTSD symptoms, and those who did not.

Adolescent↗
PubMed1997

Distress, stress and coping in first-year student nurses.

Levels of affective distress, sources of stress and coping strategies reported by first-year student nurses in Tayside, Scotland, were measured using the General Health Questionnaire (30-item version), the Beck & Srivastava Stress Inventory (BSSI) and a modified 'Ways of Coping Questionnaire'. Screening showed that, around the time of an initial series of hospital placements, 50.5% of students in cohort 1 (n = 109, week 40) and 67.9% of students in cohort 2 (n = 111, week 24) suffered significant affective distress. This exceeds levels reported in published studies of degree nursing students, fourth-year medical students, and the general female population. Distressed students reported the same sources of stress as the non-distressed students, but suffered them more intensely. Many BSSI items were seen as common sources of stress; however, the frequency with which an item was reported to be stressful was not related to whether scores on that item predicted overall distress. In both cohorts, the use of direct coping was associated with lower levels of distress, and with lower total stress scores on the BSSI. The use of fantasy and hostility was associated with high levels of distress and stress, in both groups. This screens of 220 first-year student nurses suggests that there is a problem with student distress around an initial series of general/surgical and psycho-social ward placements. The possible determinants of this distress and complex, and it is unlikely that presenting information alone will be sufficient to reduce this distress.

Adaptation, Psychological↗
PubMed1997

Localization of the Bannayan-Riley-Ruvalcaba syndrome gene to chromosome 10q23.

BACKGROUND & AIMS: Bannayan-Riley-Ruvalcaba syndrome is a congenital syndrome with characteristic features of macrocephaly, cognitive and motor dysfunction, subcutaneous and visceral lipomas and hemangiomas, and intestinal juvenile polyposis. It has been suggested that Bannayan-Riley-Ruvalcaba syndrome may be a variant of juvenile polyposis coli because of the shared features of intestinal juvenile polyps. The aim of this study was to precisely map loss of DNA from 2 patients with intestinal juvenile polyposis and karyotypic abnormalities involving chromosome 10q. METHODS: DNA was extracted from peripheral leukocytes drawn from each patient and each patient's biological parents. The DNA was amplified by polymerase chain reaction using primers specific for microsatellites located on chromosome 10q. RESULTS: Precise mapping localized a maximal distance of 1.0 cM that was commonly deleted from each patient's genome, between D10S541 and D10S1735. This area overlaps the region for Cowden disease, a distinct hamartomatous intestinal polyposis syndrome with increased risk of breast and thyroid carcinoma. CONCLUSIONS: The three hamartomatous polyposis syndromes, Bannayan-Riley-Ruvalcaba syndrome, juvenile polyposis coli, and Cowden disease, may share the same genetic defect because of their common map localization to chromosome 10q23.

Adenomatous Polyposis Coli↗
PubMed1997

Anencephaly with holoprosencephalic facies due to ring chromosome 18.

An anencephalic infant with holoprosencephalic facies and ring chromosome 18 [r(18)] is reported with review of the pertinent literature. Although the association of anencephaly and holoprosencephalic facies is well established, this is the first instance of an accompanying karyotypic abnormality. Review of other r(18) cases suggests that this is not a coincidental finding. Karyotype analysis appears warranted in cases of anencephaly with holoprosencephalic facies.

Anencephaly↗
PubMed1997

A multi-disciplinary curriculum for 11- to 13-year-olds: immunization, plus!

A sixth grade curriculum entitled "Immunization, Plus!" Was developed to promote adolescent immunization. This targeted immunization curriculum utilized contemporary learning theory and innovative teaching approaches and styles to maximize acceptability among educators. Because instructional time in school was limited, a thematic curriculum was created to embed immunization and communicable disease content within mathematics, science/health, and language arts units. The curriculum, which reflected the theory of multiple intelligences among students, offered an array of different learning formats, including linguistic, logical-mathematical, spatial, and bodily-kinesthetic. The curriculum was made available free of charge to school districts in California, and its evaluation was planned to track distribution, utilization, and changes in students' knowledge, attitude, and behavior.

Adolescent↗
PubMed1996

Holoprosencephaly in RSH/Smith-Lemli-Opitz syndrome: does abnormal cholesterol metabolism affect the function of Sonic Hedgehog?

The RSH/Smith-Lemli-Opitz syndrome (RSH/SLOS) is an autosomal recessive malformation syndrome associated with increased levels of 7-dehydro-cholesterol (7-DHC) and a defect of cholesterol biosynthesis at the level of 3 beta-hydroxy-steroid-delta7-reductase (7-DHC reductase). Because rats exposed to inhibitors of 7-DHC reductase during development have a high frequency of holoprosencephaly (HPE) [Roux et al., 1979], we have undertaken a search for biochemical evidence of RSH/SLOS and other possible defects of sterol metabolism among patients with various forms of HPE. We describe 4 patients, one with semilobar HPE and three others with less complete forms of the HPE sequence, in whom we have made a biochemical diagnosis of RSH/SLOS. The clinical and biochemical spectrum of these and other patients with RSH/SLOS suggests a role of abnormal sterol metabolism in the pathogenesis of their malformations. The association of HPE and RSH/SLOS is discussed in light of the recent discoveries that mutations in the embryonic patterning gene, Sonic Hedgehog (SHH), can cause HPE in humans and that the sonic hedgehog protein product undergoes autoproteolysis to form a cholesterol-modified active product. These clinical, biochemical, and molecular studies suggest that HPE and other malformations in SLOS may be caused by incomplete or abnormal modification of the sonic hedgehog protein and, possible, other patterning proteins of the hedgehog class, a hypothesis testable in somatic cell systems.

Cells, Cultured↗
PubMed1996

Zimmer phocomelia: delineation by principal coordinate analysis.

We present a 46,XX stillborn fetus with tetraphocomelia, absence of ears, severe hypoplasia of nose, cleft palate, pulmonary hypoplasia, imperforate anus and vagina, and phallus-like structure on an otherwise undefined perineum. The pattern of abnormalities resembles the tetraphocomelic condition described by Zimmer et al. in 1985. Tetraphocomelia, ear/nose hypoplasia with facial clefts, pulmonary hypoplasia, and defects of the caudal end including imperforate anus, and abnormal genitalia constitute a distinct pattern of malformation termed Zimmer phocomelia. Principal coordinate analysis with Gower's similarity index supported the clinical impression that cases reported by Zimmer and the present case are distinct from other phocomelic conditions. Although Zimmer phocomelia is currently referred to as "X-linked amelia," documentation of a female case with a penis-like structure in this report as well as consanguinity in the original family in Zimmer's report indicates that this condition is likely inherited in an autosomal recessive fashion. Zimmer phocomelia may be a more appropriate name than X-linked amelia.

Abnormalities, Multiple↗
PubMed1996

Rethinking metalinguistic awareness: representing and accessing knowledge about what counts as a word.

Developmentalists have argued that young children have a confused notion of the metalinguistic concept word and that they cannot focus on single word boundaries when words occur in normal syntactic/semantic frames. We challenge these assumptions and present a new technique which engages normal syntactic-semantic processing but which, once it is interrupted on-line, introduces a metalinguistic component. In three experiments, children listened to a story in which the narrator paused on open or closed class words and then asked children to repeat "the last word" or "the last thing" that she had said each time she stopped. The results show that children as young as 4 1/2-5 years treat both open and closed categories as words and clearly differentiate word and thing. We conclude by suggesting that the new technique may be useful for enhancing early reading readiness and for reassessing the relationship between literacy and metalinguistic awareness.

Awareness↗
PubMed1996

Sudden death in Williams syndrome: report of ten cases.

Williams syndrome (WS) is a recognizable pattern of malformation with mental retardation, mild growth deficiency, characteristic facies and temperament, and cardiovascular disease. Sudden death is a recognized complication of WS; however, it is thought to be rare. The clinical features of 10 children with WS who died suddenly are reported here, doubling the number of unexpected deaths reported in the literature. We suggest that sudden death is a more common complication than has been assumed previously. Pathologic findings on the seven autopsy cases implicate two anatomic abnormalities that predispose individuals with WS to sudden death: coronary artery stenosis and severe biventricular outflow tract obstruction. The mechanisms for sudden death for both anatomic subgroups include myocardial ischemia, decreased cardiac output, and arrhythmia. We believe these observations warrant the development of strategies for monitoring patients with WS in an attempt to identify those at increased risk of sudden death.

Aortic Valve↗