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Biomedical subjects

J McGrath

Publications and source records attributed to J McGrath.

At least 55 records · Page 3Linked to original sources
PubMed1999

A survey of contact with offspring and assistance with child care among parents with psychotic disorders.

To help improve services for parents with psychotic disorders, patients with such disorders in three treatment agencies in Queensland, Australia, were surveyed about whether they were parents, how much contact they had with their offspring, and who provided assistance with child care. Of the 342 individuals with psychotic disorders who participated in the study, 124 were parents. Forty-eight parents in the study had children under age 16, and 20 of these parents (42 percent) had their children living with them. Most parents relied on relatives or friends for assistance with child care. Barriers to child care services identified by parents were inability to pay, lack of local services, and fear of losing custody of children.

Adult↗
PubMed1999

Targeted deletion of the ATP binding domain of left-right dynein confirms its role in specifying development of left-right asymmetries.

Vertebrates develop distinct asymmetries along the left-right axis, which are consistently aligned with the anteroposterior and dorsoventral axes. The mechanisms that direct this handed development of left-right asymmetries have been elusive, but recent studies of mutations that affect left-right development have shed light on the molecules involved. One molecule implicated in left-right specification is left-right dynein (LRD), a microtubule-based motor protein. In the LRD protein of the inversus viscerum (iv) mouse, there is a single amino acid difference at a conserved position, and the lrd gene is one of many genes deleted in the legless (lgl) mutation. Both iv and lgl mice display randomized left-right development. Here we extend the analysis of the lrd gene at the levels of sequence, expression and function. The complete coding sequence of the lrd gene confirms its classification as an axonemal, or ciliary, dynein. Expression of lrd in the node at embryonic day 7.5 is shown to be symmetric. At embryonic day 8.0, however, a striking asymmetric expression pattern is observed in all three germ layers of the developing headfold, suggesting roles in both the establishment and maintenance of left-right asymmetries. At later times, expression of lrd is also observed in the developing floorplate, gut and limbs. These results suggest function for LRD protein in both ciliated and non-ciliated cells, despite its sequence classification as axonemal. In addition, a targeted mutation of lrd was generated that deletes the part of the protein required for ATP binding, and hence motor function. The resulting left-right phenotype, randomization of laterality, is identical to that of iv and lgl mutants. Gross defects in ciliary structure were not observed in lrd/lrd mutants. Strikingly, however, the monocilia on mutant embryonic node cells were immotile. These results prove the identity of the iv and lrd genes. Further, they argue that LRD motor function, and resulting nodal monocilia movement, are required for normal left-right development.

Adenosine Triphosphate↗
PubMed1998

Factors determining outcome for breast-conserving irradiation with margin-directed dose escalation to the tumor bed.

PURPOSE: A prospectively applied treatment policy for breast-conserving therapy used margin assessment as the exclusive guide to the intensity of therapy directed at the tumor-bearing quadrant. METHODS AND MATERIALS: From 1982-1994, there were 509 treated Stage I and II breast carcinomas with a median follow-up of 72 months. For operational purposes, tumor excision margins were prospectively defined as: > 5 mm, 2.1-5 mm, > 0 < or = 2 mm, and positive. If a margin was assessed as < or = 2 mm or indeterminate, and it was deemed cosmetically feasible, a reexcision of the tumor bed would be performed. All patients received whole breast irradiation to 50-50.4 Gy. The following scheme for tumor bed boost irradiation as a function of final margin status (FMS) was observed: (a) Minimal risk = no tumor found on reexcision, no boost performed; (b) low risk = FMS > 5 mm, boost of 10 Gy; intermediate risk = FMS 2.1-5 mm, boost to 14 Gy; high risk = FMS < or = 2 mm or positive, boost to 20 Gy. Cases were analyzed for local failure (LF) with respect to histology (invasive ductal (IDC), IDC with associated DCIS (IDC/DCIS), invasive lobular (ILC)), age, tumor size, total excision volume, reexcision, total dose, tamoxifen therapy, and chemotherapy. RESULTS: There were 19 breast recurrences for a Kaplan-Meier local failure rate for all cases at 5 and 10 years of 2.7% and 7.1%, respectively. Local failure in the first 4 years of follow-up was rare, with a mean annual incidence rate of 0.25% that rose to a mean of 1.1% in subsequent years. Univariate results of Cox proportional hazards regression survival models found positive FMS (p = 0.02), IDC/DCIS (p = 0.04) and age (0.0006) as significantly associated with local failure. In a multivariable model of FMS and IDC/DCIS, FMS retained significance (p = 0.01) but IDC/DCIS was borderline (p = 0.06). When FMS and age were included in a multivariable model, there was a significant interaction (p = 0.01) between the two variables. There was a significant increase in the relative risk of LF for age < or = 45 years (range 11.1-17.4), irrespective of FMS category. Although excellent overall control rates were achieved for patients > 45 years, for younger patients LF rates appeared to remain proportional to the relative closeness of the FMS, despite rigorous dose escalation. CONCLUSIONS: Graded tumor-bed dose escalation in response to FMS results in an exceptionally low risk of "early" local recurrence within the first 5 years of follow-up. However, this strategy is unable to completely overcome the longer term adverse influence of young age and positive FMS.

Adult↗
PubMed1998

Arrest among psychotic inpatients: assessing the relationship to diagnosis, gender, number of admissions, and social class.

The present study of psychotic patients investigates the relationship of specific psychotic diagnoses (i.e., psychoactive-substance-induced psychosis, schizophrenia, bipolar disorder, other DSM-III Axis I psychotic disorders), social class, gender, and number of admissions to the rate of arrest in the community. All admissions with psychotic symptoms to hospitals providing inpatient psychiatric services in the Baltimore area were surveyed during a 6-year period. Study participants were assessed using a modified version of the Diagnostic Interview Schedule. During the course of the interview, patients were asked whether they had ever been arrested as a juvenile or as an adult. After adjusting for age, gender, number of admissions, and social class, we found that patients admitted for psychoactive-substance-induced psychosis were more likely to report having been arrested than patients with other psychotic diagnoses. Patients with schizophrenia were not more likely to have an history of arrest than patients with other psychotic disorders. Number of admissions and social class were independent predictors of history of arrest. The relationship between psychotic diagnosis and history of arrest was modified by gender. Psychotic patients with substance-induced diagnosis who were male were more likely to report a prior arrest in the community than their female counterparts. Our results suggest that type of psychotic diagnosis and social class, in addition to gender and number of admissions, are important predictors of differences in arrest-rate histories among psychotic patients. Gender appears to be an effect modifier of the relationship between psychotic diagnosis and history of arrest.

Adolescent↗
PubMed1998

The efficiency of acute care bed utilization in Newfoundland and Labrador.

Hospital efficiency is closely related to utilization levels and length of stay. This study determined whether inappropriate bed utilization in Newfoundland was related to inefficiency or inadequate access to alternative services. It also compared Canadian Institute for Health information (CIHI) data to our survey to determine whether they provide comparable information for monitoring efficiency. Inappropriate acute care days were identified using a modified Appropriateness Evaluation Protocol. Average length of stay (ALOS) by service for each of the province's acute care institutions was also reviewed from 1993-94 to 1995-96 using the CIHI database. Hospital admissions were Inappropriate in 14.2 percent of 2,007 cases. Of the 14,194 days of care, 22.8 percent were inappropriate, with most (16.4 percent) being avoidable with better use of existing resources. Of the inappropriate days, 49.2 percent related to physicians' functions. The provincial ALOS fell from 5.70 days in 1993-94 to 5.39 days in 1995-96, but remains 10.5 percent above the national average.

Data Collection↗
PubMed1998

Provider attitudes toward IUD provision in Zimbabwe: perception of HIV risk and training implications.

This study was conducted to assess providers' attitudes toward the provision of long-term methods of contraception, in particular the IUD, and provider concerns about human immunodeficiency virus (HIV) in the context of family planning (FP) services. The data were collected using self-administered structured questionnaires. Between 65% and 80% of the public and private providers thought that the IUD is a good contraceptive method for Zimbabwean women. In addition, the majority of these two provider groups felt that neither the IUD nor tubal sterilization (TL) posed much risk of HIV infection to the client. A significant number of providers (especially the public nurses), however, thought that the provision of TL put the provider at high risk of HIV infection and a significant proportion of public nurses were also concerned about provider risk associated with providing IUD and injectables. To address such concerns, future training interventions should emphasize appropriate infection prevention practices associated with surgical FP method provision. Nurses, in particular, should be informed about the magnitude of risk associated with FP service provision and ways to protect themselves. Logistic activities also need to be strengthened so that legitimate concerns among providers regarding lack of adequate infection prevention supplies (e.g. gloves) in the field can be addressed.

Attitude of Health Personnel↗
PubMed1998

Schizophrenia susceptibility loci on chromosomes 13q32 and 8p21.

Schizophrenia is a common disorder characterized by psychotic symptoms; diagnostic criteria have been established. Family, twin and adoption studies suggest that both genetic and environmental factors influence susceptibility (heritability is approximately 71%; ref. 2), however, little is known about the aetiology of schizophrenia. Clinical and family studies suggest aetiological heterogeneity. Previously, we reported that regions on chromosomes 22, 3 and 8 may be associated with susceptibility to schizophrenia, and collaborations provided some support for regions on chromosomes 8 and 22 (refs 9-13). We present here a genome-wide scan for schizophrenia susceptibility loci (SSL) using 452 microsatellite markers on 54 multiplex pedigrees. Non-parametric linkage (NPL) analysis provided significant evidence for an SSL on chromosome 13q32 (NPL score=4.18; P=0.00002), and suggestive evidence for another SSL on chromosome 8p21-22 (NPL=3.64; P=0.0001). Parametric linkage analysis provided additional support for these SSL. Linkage evidence at chromosome 8 is weaker than that at chromosome 13, so it is more probable that chromosome 8 may be a false positive linkage. Additional putative SSL were noted on chromosomes 14q13 (NPL=2.57; P=0.005), 7q11 (NPL=2.50, P=0.007) and 22q11 (NPL=2.42, P=0.009). Verification of suggestive SSL on chromosomes 13q and 8p was attempted in a follow-up sample of 51 multiplex pedigrees. This analysis confirmed the SSL in 13q14-q33 (NPL=2.36, P=0.007) and supported the SSL in 8p22-p21 (NPL=1.95, P=0.023).

Adult↗
PubMed1998

Homozygous variegate porphyria: identification of mutations on both alleles of the protoporphyrinogen oxidase gene in a severely affected proband.

Homozygous variegate porphyria is a severe skin and neurologic disease manifesting in early infancy, and characterized by markedly reduced levels of the penultimate enzyme in the heme biosynthetic pathway, protoporphyrinogen oxidase. We investigated the molecular basis of variegate porphyria, usually an autosomal dominantly inherited trait, in a severely affected female proband and her parents. The mutation detection strategy included heteroduplex analysis, automated sequencing, and allele specific oligonucleotide hybridization. We identified two underlying missense mutations in the protoporphyrinogen oxidase gene, consisting of a G-to-A transition in exon 6 (G169E), and a G-to-A transition in exon 10 (G358R). Our study establishes the molecular basis of "homozygous" variegate porphyria for the first time, in demonstrating that this patient is a compound heterozygote for two different missense mutations in the protoporphyrinogen oxidase gene.

Adult↗
PubMed1998

Neuroleptic management of schizophrenia: a survey and commentary on Australian psychiatric practice.

OBJECTIVE: We seek to assess Australian psychiatrists' views and practices concerning provision of neuroleptic medication to patients with schizophrenia, and to determine whether such management strategies are likely to have changed over time and the extent to which they correspond to published treatment guidelines. METHOD: A sample of 139 psychiatrists based in three Australian capital cities was derived, with respondents completing a brief questionnaire by choosing from a limited-option answer set. Co-authors of this paper comment on the extent to which responses are in line with contemporary recommendations driven by experts or empirical studies. RESULTS: Overall, survey findings indicate that there has been considerable change in clinical practice over the last decade and provide some estimate of the extent to which Australian management practices are congruent with contemporary recommendations. We identify a number of issues of concern (more in relation to dose levels of neuroleptic medication rather than treatment duration) revealed by survey data and make recommendations for addressing a number of practical clinical issues. CONCLUSIONS: As this report focuses on central issues involved in managing schizophrenia, and integrates a number of treatment guidelines, we suggest that it should be of assistance for practice review by clinicians.

Antipsychotic Agents↗
PubMed1998

Developmentally regulated expression of the novel cancer anti-apoptosis gene survivin in human and mouse differentiation.

Inhibitors of programmed cell death (apoptosis) may regulate tissue differentiation and aberrantly promote cell survival in neoplasia. A novel apoptosis inhibitor of the IAP gene family, designated survivin, was recently found in all of the most common human cancers but not in normal, terminally differentiated adult tissues. The expression of survivin in embryonic and fetal development was investigated. Immunohistochemistry and in situ hybridization studies demonstrated strong expression of survivin in several apoptosis-regulated fetal tissues, including the stem cell layer of stratified epithelia, endocrine pancreas, and thymic medulla, with a pattern that did not overlap with that of another apoptosis inhibitor, bcl-2. A sequence-specific antibody to survivin immunoblotted a single approximately 16.5-kd survivin band in human fetal lung, liver, heart, kidney, and gastrointestinal tract. In mouse embryo, prominent and nearly ubiquitous distribution of survivin was found at embryonic day (E)11.5, whereas at E15 to -21, survivin expression was restricted to the distal bronchiolar epithelium of the lung and neural-crest-derived cells, including dorsal root ganglion neurons, hypophysis, and the choroid plexus. These data suggest that expression of survivin in embryonic and fetal development may contribute to tissue homeostasis and differentiation independently of bcl-2. Aberrations of this developmental pathway may result in prominent re-expression of survivin in neoplasia and abnormally prolonged cell viability.

Animals↗
PubMed1997

Antibodies capable of releasing diphtheria toxin in response to the low pH found in endosomes.

Diphtheria toxin (DT) undergoes a rapid conformational change in response to the acidity encountered within endosomes. That transition is integral to the passage of its catalytic domain into the cytosol and thus its lethal action. The importance of this translocation mechanism led us to develop several monoclonal antibodies that bind DT at neutral pH but spontaneously release the toxin when critical epitopes denature or unfold upon lowering the pH to 4.5-5.5. Hybridomas were selected using a microtiter plate assay that measured the pH-dependent detachment of antibody from immobilized toxin. The acid-sensitive epitopes involved were on the catalytic, transmembrane, and receptor binding domains of DT. This pH-induced disruption of the binding of toxin to these monoclonal antibodies was analyzed by sedimentation velocity ultracentrifugation. Antibody combining sites were fully occupied at pH 5.5, partially bound at pH 5.0, and totally empty at pH 4.5. It was estimated that the Ka for antibody-toxin binding was approximately 1000-fold lower at pH 5.0 than at neutral pH. This novel acid-triggered release mechanism provides a basis for delivery of antibody-bound toxin into cells accompanied by its immediate dissociation as the complex enters acidic vesicles.

Antibodies, Monoclonal↗
PubMed1997

Intracellular targeting with low pH-triggered bispecific antibodies.

Bispecific antibodies were designed to deliver a reversibly bound ligand into target cells and then spontaneously release it upon passage into acidified vesicles. These reagents were assembled by coupling monoclonal antibodies that recognize acid-sensitive epitopes on diphtheria toxin to cell type-specific monoclonal antibodies. The dual binding capacity of the bispecific antibodies was confirmed by delivery of 125I-diphtheria toxin to target molecules present on intact cells. Bispecific antibodies directed against transferrin receptors on human cells were loaded with toxin and tested for cytotoxicity. The mutant diphtheria toxins CRM107 and CRM45 were used since their inability to bind cell receptors renders them ordinarily nontoxic. Their full cytotoxic potential, however, was restored via bispecific antibody-mediated delivery and release within low pH intracellular vesicles. Cytotoxicity was shown to be specific by blocking receptor sites and to be acidification-dependent by protection using NH4Cl to raise endosomal pH. Kinetics for inhibition of cellular protein synthesis was identical for native diphtheria toxin and the bispecific antibody. CRM107 combination. The rate of inhibition (t1/2 = 20 min) indicated that release of CRM107 from the antibody combining site was fast, and its toxic action was unimpeded by this delivery mechanism.

Antibodies, Bispecific↗
PubMed1997

Performance on tests sensitive to impaired executive ability in schizophrenia, mania and well controls: acute and subacute phases.

AIMS: To compare the performance of schizophrenia, mania and well control groups on tests sensitive to impaired executive ability, and to assess the within-group stability of these measures across the acute and subacute phases of psychoses. METHOD: Recently admitted patients with schizophrenia (n = 36), mania (n = 18) and a well control group (n = 20) were assessed on two occasions separated by 4 weeks. Tests included: the Controlled Oral Word Association Test, the Stroop Test, the Wisconsin Card Sort Test, and the Trail Making Test. RESULTS: The two patient groups were significantly impaired on the Stroop Test at both time points compared to the control group. Significant group differences were also found for the Trail Making Test at Time 1 and for the Wisconsin Card Sort Test at Time 2. When controlled for practice effect, significant improvements over time were found on the Stroop and Trail Making tests in schizophrenia group and on WCST Categories Achieved in the mania group. DISCUSSION: Compared to controls, the patient groups were impaired on measures related to executive ability. The pattern of improvement on test scores between the acute and subacute phases differed between patients with schizophrenia versus patients with mania.

Acute Disease↗
PubMed1997

A complex chromosome rearrangement with at least five breakpoints studied by fluorescence in situ hybridization.

A newborn infant with multiple congenital anomalies was diagnosed with an unbalanced translocation of chromosomes 1 and 5. Studies of parental chromosomes revealed a complex rearrangement in the patient's mother involving the exchange of terminal long arms between chromosomes 1 and 5 and the insertion of an interstitial segment from the same chromosome 5q into chromosome 2q by high-resolution G-banding. Further study of the mother's chromosomes by fluorescent in situ hybridization (FISH) detected an additional insertion between the rearranged chromosomes 2 and 5, which was not revealed by G-banding. This led to the identification of a complex translocation-insertion between 3 chromosomes with at least 5 breaks [t(1;5;2)(1pter--> 1q42.3::5q23.2-->5qter;5pter-->5q21.2:: 2q33--> 2q35::1q42.3-->1qter;2pter-->2q33::5q21 .2--> 5q23.2::2q35-->2qter)] and illustrates the value of FISH as an adjunct to standard cytogenetics, particularly in cases of complex rearrangements.

Abnormalities, Multiple↗
PubMed1997

Treatment of coronary artery disease in an anomalous coronary artery by placement of an intracoronary stent.

We report the use of coronary stenting to treat disease in an anomalous coronary artery. The patient had a single coronary artery with anomalous left anterior descending artery arising from the right sinus of Valsalva and coursing between the aorta and pulmonary artery. Although balloon angioplasty has been used in patients with anomalous coronary arteries, this is the first report of stent placement in this circumstance.

Angioplasty, Balloon↗
PubMed1997

Matrix-attachment regions in the mouse chromosome 7F imprinted domain.

We have mapped the matrix-attachment regions (MARs) in 200 kilobases of the mouse Chromosome (Chr) 7F imprinted domain. MARs are genetic elements known to have effects in cis on methylation at nonimprinted loci. The imprinting of the Igf2 and Ins2 genes is dependent on the transcription of the downstream H19 gene. The transcription of H19 is dependent in turn on its methylation status. The cis-acting regulators of methylation at this site are not known. As MARs are potential regulators not only of methylation but also other elements of genomic imprinting, we mapped the MARs within the 200 kilobases around H19. This report describes the mapping of four MARs from this region.

Animals↗