Biomedical subjects

J G Rogers

Publications and source records attributed to J G Rogers.

At least 19 recordsLinked to original sources

PubMed2006

Effect of age on outcomes after left ventricular assist device placement.

The influence of age on outcomes after left ventricular assist device (LVAD) implantation is not well studied. To address this question, we assessed 222 patients who underwent LVAD placement and were divided into quartiles based on age (years): group 1, or=60. Eighty-four patients died on LVAD support. Six- and 12-month survivals for the four groups of LVAD patients were 67.7, 73.7, 49.8, and 38.2, and 49.4, 57.3, 42.7, and 26.2, respectively (all P<.01). Older patients showed a higher risk of infections, embolic strokes, and respiratory complications. They were the least likely to undergo reoperations postimplantation (56%, 53%, 50%, 46%, P=.06). After adjusting for baseline differences between the groups, there was a trend toward increasing mortality with age, which did not reach significance (odds ratio 1.93; 95% confidence interval 0.95 to 3.92 for the oldest quartile as compared with the youngest). In conclusion, these results suggest in the absence of other high risk factors, age alone should not be used as an independent contraindication for LVAD implantation.

Adult↗

PubMed2003

21Na(p,gamma)22Mg reaction and oxygen-neon novae.

The 21Na(p,gamma)22Mg reaction is expected to play an important role in the nucleosynthesis of 22Na in oxygen-neon novae. The decay of 22Na leads to the emission of a characteristic 1.275 MeV gamma-ray line. This report provides the first direct measurement of the rate of this reaction using a radioactive 21Na beam, and discusses its astrophysical implications. The energy of the important state was measured to be E(c.m.)=205.7+/-0.5 keV with a resonance strength omegagamma=1.03+/-0.16(stat)+/-0.14(sys) meV.

Journal Article↗

PubMed2000

Cultural aspects of disability.

This article describes cultural and social issues related to disability based on the authors' experiences as researchers, clinicians, and activists and personal experience. They address the complexity of the topic of disability subculture by arguing that there is not one disability subculture and then describe common themes that characterize the social context of people with disabilities and one highly visible disability subculture. Clinical and research implications are mentioned. The definition of culturally competent care should be broadened to include disability.

Cultural Characteristics↗

PubMed1999

An autosomal dominant or X-linked osteodysplastic disorder with severe cervical involvement.

A disorder affecting bone and cartilage growth is described in a mother and her 3-year-old son. A dysplastic process involving the vertebral bodies, most pronounced in the cervical region and leading to cervical dislocation in the first of these two patients, is the most significant complication of this disorder. This entity appears unrelated to other previously described skeletal dysplasias with cervical kyphosis as a major manifestation. This disorder is most likely autosomal dominant.

Adult↗

PubMed1998

Photopheresis for the prevention of rejection in cardiac transplantation. Photopheresis Transplantation Study Group.

BACKGROUND: Photopheresis is an immunoregulatory technique in which lymphocytes are reinfused after exposure to a photoactive compound (methoxsalen) and ultraviolet A light. We performed a preliminary study to assess the safety and efficacy of photopheresis in the prevention of acute rejection of cardiac allografts. METHODS: A total of 60 consecutive eligible recipients of primary cardiac transplants were randomly assigned to standard triple-drug immunosuppressive therapy (cyclosporine, azathioprine, and prednisone) alone or in conjunction with photopheresis. The photopheresis group received a total of 24 photopheresis treatments, each pair of treatments given on two consecutive days, during the first six months after transplantation. The regimen for maintenance immunosuppression, the definition and treatment of rejection episodes, the use of prophylactic antibiotics, and the schedule for cardiac biopsies were standardized among all 12 study centers. All the cardiac-biopsy samples were graded in a blinded manner at a central pathology laboratory. Plasma from the subgroup of 34 patients (57 percent) who were enrolled at the nine U.S. centers was analyzed by polymerase-chain-reaction amplification for cytomegalovirus DNA. RESULTS: After six months of follow-up, the mean (+/-SD) number of episodes of acute rejection per patient was 1.44+/-1.0 in the standard-therapy group, as compared with 0.91+/-1.0 in the photopheresis group (P=0.04). Significantly more patients in the photopheresis group had one rejection episode or none (27 of 33) than in the standard-therapy group (14 of 27), and significantly fewer patients in the photopheresis group had two or more rejection episodes (6 of 33) than in the standard-therapy group (13 of 27, P=0.02). There was no significant difference in the time to a first episode of rejection, the incidence of rejection associated with hemodynamic compromise, or survival at 6 and 12 months. Although there were no significant differences in the rates or types of infection, cytomegalovirus DNA was detected significantly less frequently in the photopheresis group than in the standard-therapy group (P=0.04). CONCLUSIONS: In this pilot study, the addition of photopheresis to triple-drug immunosuppressive therapy significantly decreased the risk of cardiac rejection without increasing the incidence of infection.

Combined Modality Therapy↗

PubMed1998

Cerebrospinal fluid shunts in the management of behavioural problems in Sanfilippo syndrome (MPS III).

UNLABELLED: Severe behavioural disturbance is a very common feature of Sanfilippo syndrome (mucopolysaccharidosis III, MPSIII), and one of the more difficult aspects of the disease to treat. We describe a series of six patients with MPS III who had cerebrospinal shunts inserted in an attempt to ameliorate behaviour that had proved refractory to conventional treatment. Symptoms improved significantly in all six but removal of the shunt was necessitated in one patient due to shunt blockage and infection. CONCLUSION: Our experience suggests cerebrospinal fluid shunting should be formally evaluated as an adjunct to conventional forms of treatment of extreme behavioural disturbance in MPS III.

Adolescent↗

PubMed1998

Medical complications of achondroplasia: a multicentre patient review.

Achondroplasia is the most prevalent chondrodysplasia and numerous authors have documented the varied social and medical complications that may compromise a full and productive life. Complications include cervicomedullary compression, spinal stenosis, restrictive and obstructive lung disease, otitis media, and tibial bowing, among others. These known complications have led to recommendations for the anticipatory management of such patients. There are relatively few data on the actual rates and timing of these problems. This paper reports data on the rates and age of occurrence of several of these complications based on a review of recorded chart information of 193 patients ascertained from several well established genetic centres with a known interest in the chondrodysplasias. The length of follow up varied and the rates of occurrence at specific age intervals were used to estimate the cumulative percentage affected for each complication. The report includes information on otitis media, ventilation tubes, hearing loss, tonsillectomy, speech problems, tibial bowing and osteotomy, ventricular shunting, apnoea, cervicomedullary decompression, and neurological signs attributable to spinal stenosis.

Achondroplasia↗

PubMed1998

The human plasminogen activator inhibitor type I gene promoter targets to kidney.

The plasminogen activator inhibitor type 1 (PAI-1) gene encodes the physiological inhibitor of tissue-type and urokinase-type plasminogen activators and is induced by cytokines such as transforming growth factor-beta (TGF-beta). Studies have identified DNA sequence elements within the first 1.3 kb of the 5'-upstream DNA that mediate cytokine responsiveness in transfected cells in vitro. However, the DNA sequences that mediate PAI-1 expression in vivo have not yet been delineated. To define these regulatory sequences, we generated transgenic mice that expressed a hybrid gene comprising sequences between -1,272 and +75 of the human PAI-1 gene ligated to a LacZ reporter gene. Transgene expression detected in two independent lines was observed only in kidney from embryonic day 13 to adult and was seen primarily in proximal tubule cells of the outer medulla. Transgene expression and activity were unchanged in response to TGF-beta and remained restricted to kidney. Thus we have identified a promoter region within the PAI-1 gene that targets transgene expression to kidney but, unlike the native promoter, is unresponsive to TGF-beta in the experimental protocol used.

Animals↗

PubMed1998

The genetics of fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva is an autosomal dominant disorder. Most cases are due to new gene mutations because people with fibrodysplasia ossificans progressiva have markedly reduced reproductive fitness. The gene or genes responsible for this disorder are unknown.

Child↗

PubMed1997

Transmyocardial laser revascularization for inoperable coronary artery disease.

Interest in transmyocardial laser revascularization for the treatment of otherwise inoperable coronary artery disease has increased rather dramatically in recent years. The results of several industrially sponsored clinical series have been reported recently, all with significant improvement in angina pectoris that appears both rapid and sustained. In most instances, an associated improvement in exercise tolerance has been reported. Improvement in regional myocardial perfusion has been proclaimed, although it is less consistent and less complete than symptom relief. The mechanisms whereby this clinical effect is achieved remain unknown. Histologic analysis of autopsy material has yielded somewhat conflicting results regarding the persistent patency of laser-created channels. The results of laboratory investigations of this therapy have been equally inconsistent. Despite our ignorance regarding the mechanism of angina relief, clinical experience continues to grow. In addition to the CO2 laser energy source used in early studies, trials of alternative devices using holmium:yttrium-aluminum-garnet and eximer lasers are underway. The latter two employ fiberoptic technology and are currently under development for endovascular approaches.

Angina Pectoris↗

PubMed1996

Pitt-Rogers-Danks syndrome: the result of a 4p microdeletion.

Pitt-Rogers-Danks syndrome (PRDS) is a rare, presumed autosomal recessive, syndrome with pre- and postnatal growth retardation, microcephaly, characteristic facial appearance, seizures, unusual palmar creases and developmental delay. Since the first description in 1984, only 7 cases have been reported. We report the identification of a 4p microdeletion in 2 new patients, who were previously diagnosed with PRDS, as well as the sibs in Pitt et al. [1984]. PRDS can no longer be considered autosomal recessive. Although our cases are attributable to a microdeletion in 4p16, it is uncertain if the critical region involves a single locus or multiple loci or to what extent this region overlaps with the critical region for Wolf-Hirschhorn syndrome.

Abnormalities, Multiple↗

PubMed1996

Disrupted growth plates and progressive deformities in osteogenesis imperfecta as a result of the substitution of glycine 585 by valine in the alpha 2 (I) chain of type I collagen.

The skeleton of a child with osteogenesis imperfecta type III, resulting from the substitution of glycine 586 by valine in the triple helical domain of the alpha 2 (I) chain of type I collagen, was severely porotic but contained lamellar bone and Haversian systems. From early childhood, structural failure of the bone resulted in the disruption of growth plates, progressive bone deformities, and severe growth retardation.

Adolescent↗

PubMed1996

Anaesthesia for children with mucopolysaccharidoses.

The mucopolysaccharidoses are a group of inherited disorders of metabolism, with varying clinical manifestations. A number of them present anaesthetic difficulties. This paper presents a summary table of the syndromes and reviews our experience over ten years with patients with these diagnoses. The clinical presentations, anaesthetic management, and complications are described. The effect of age and diagnosis on airway difficulties was studied. There were 31 patients, 28 of whom required anaesthesia, on a total of 99 occasions, for 115 procedures. The patients with Hunter, Hurler and Maroteaux-Lamy syndromes had significantly more airway difficulties as they grew older, and compared with patients in this group with other syndromes. Patients with Hurler's syndrome may have coronary artery involvement and one patient was given fentanyl and pancuronium for this reason. He proved impossible to intubate and an emergency tracheostomy was performed.

Adolescent↗

PubMed1995

Type X collagen multimer assembly in vitro is prevented by a Gly618 to Val mutation in the alpha 1(X) NC1 domain resulting in Schmid metaphyseal chondrodysplasia.

Type X collagen is a homotrimer of alpha 1(X) chains encoded by the COL10A1 gene. It is a highly specialized extracellular matrix component, and its synthesis is restricted to hypertrophic chondrocytes in the calcifying cartilage of the growth plate and in zones of secondary ossification. Our studies on a family with Schmid metaphyseal chondrodysplasia demonstrated that the affected individuals were heterozygous for a single base substitution in the COL10A1 gene, which changed the codon GGC for glycine 618 to GTC for valine in the highly conserved region of the carboxyl-terminal NC1 domain and altered the amino acid sequence in the putative oligosaccharide attachment site. Since hypertrophic cartilage tissues or cell cultures were not available to assess the effect of the mutation, an in vitro cDNA expression system was used to study normal and mutant type X collagen biosynthesis and assembly. Full-length cDNA constructs of the normal type X collagen sequence and also cDNA containing the specific Gly to Val NC1 mutation found in the patient were produced and expressed by in vitro transcription and translation. While the control construct produced type X collagen, which formed trimeric collagen monomers and assembled into larger multimeric assemblies, the mutant collagen was unable to form these larger aggregates. These experiments demonstrated that the mutation disturbed type X collagen NC1 domain interaction and assembly, a finding consistent with the abnormal disorganized cartilage growth plate seen in the patient. These studies provide the first evidence of the effect of a type X collagen mutation on protein structure and function and directly demonstrate the critical role of interactions between NC1 domains in the formation of type X collagen multimeric structures in vitro.

Amino Acid Sequence↗

PubMed1995

Severe intrauterine growth retardation with increased mitomycin C sensitivity: a further chromosome breakage syndrome.

We report an infant with pre- and postnatal microcephaly and growth retardation, a distinctive face, and developmental delay. The initial diagnosis was of Seckel syndrome. He became pancytopenic at 16 months and died soon after. His bone marrow was of normal cellularity but had a small lymphocyte infiltration. Increased spontaneous chromosome breakage was seen in blood and fibroblasts. Mitomycin C induced chromosome damage was increased and comparable to that seen in Fanconi anaemia. Reports of similar patients are reviewed. This entity of severe intrauterine growth retardation and increased mitomycin C sensitivity is hypothesised to be a distinct chromosome breakage syndrome.

Adult↗

PubMed1994

Osteomesopycnosis.

The radiographic findings in two children with osteomesopycnosis are described. This is the first report in the Australian literature of this uncommon, recently described entity.

Adolescent↗

PubMed1994

Two sibs who are double heterozygotes for achondroplasia and pseudoachondroplastic dysplasia.

We report a family in which two sibs have both achondroplasia and pseudoachondroplastic dysplasia. The mother has achondroplasia and the father has pseudoachondroplastic dysplasia, which he had inherited from his father. Both children appeared typical of achondroplasia at birth. By 1 1/2 years they had developed a fixed lumbar kyphosis with gibbus and had additional x ray changes unusual for just achondroplasia and suggestive of pseudoachondroplastic dysplasia. Subsequently both children have shown characteristic features of both conditions and have grown less well than expected for achondroplasia. Radiographs show the striking synergistic effects of the two conditions. MRI in both sibs confirmed brain stem compression at the foramen magnum. This may be an important complication and should be actively sought in any double heterozygote.

Achondroplasia↗

PubMed1993

The clinical features of spondyloepiphyseal dysplasia congenita resulting from the substitution of glycine 997 by serine in the alpha 1(II) chain of type II collagen.

The features of a child with spondyloepiphyseal dysplasia congenita resulting from a mutation in one COL2A1 allele were studied. The child was heterozygous for a G to A transition in exon 48 that resulted in the substitution of glycine 997 by serine in the triple helical domain of alpha 1(II) chains of type II collagen. Her longitudinal growth was close to the mean growth curve for children with this chondrodysplasia. Expression of the mutation by chondrocytes would account for the abnormal growth and development of the bones of the limbs and spine. Early expression of the mutation by epithelial cells and later expression by chondrocytes of the developing craniofacial structures would also account for her complex pattern of craniofacial anomalies. The findings in this study confirm that mutations of exon 48 of the COL2A1 gene, that alter the normal Gly-X-Y triplet structure of the corresponding region of alpha 1(II) chains of type II collagen, produce the spondyloepiphyseal dysplasia congenita phenotype.

Collagen↗