Search PubMedSearch

Biomedical subjects

J Harding

Publications and source records attributed to J Harding.

13 recordsLinked to original sources

A new transthyretin mutation associated with amyloidotic vitreous opacities. Asparagine for isoleucine at position 84.

An inherited type of amyloidosis was suspected in an individual of Italian descent who presented with vitreous opacities. Although no family history of amyloidosis was apparent, the patient's transthyretin gene was examined and found not to possess any of the known transthyretin mutations. Complete DNA sequencing revealed a substitution of adenine for thymine in the second base of codon 84 causing an amino acid change of asparagine for isoleucine. The mutation was confirmed by demonstrating the loss of an Sfa N1 restriction endonuclease site. Allele-specific DNA amplification by polymerase chain reaction also was used to confirm the mutation. Either of these tests can be used for diagnosis. Asparagine 84 represents the second mutation associated with amyloidosis to occur at codon 84.

Aged

Analysis of the effects of task preferences, task demands, and adult attention on child behavior in outpatient and classroom settings.

Two studies were conducted with children who displayed behavior problems to evaluate the effects of task preference, task demands, and adult attention on child behavior. In Study 1, we conducted brief functional analyses in an outpatient clinic to identify variables that facilitated appropriate behavior. For 8 of 10 children, distinct patterns of performance occurred; 3 children displayed improved behavior with changes in task demands, 1 child displayed improved behavior with a preferred task, and 4 children displayed improved behavior with changes in adult attention. In most cases, the children's parents carried out the assessments with adequate procedural integrity. In Study 2, we applied similar assessment methods to a classroom setting over an extended period of time. We identified independent variables controlling appropriate, on-task, and academic behavior for 2 children on two tasks, with slightly different treatment procedures across tasks for both children. In addition, the results of brief functional analyses for both children corresponded to the extended classroom assessments.

Adjustment Disorders

A second transthyretin mutation at position 33 (Leu/Phe) associated with familial amyloidotic polyneuropathy.

Genomic DNA was isolated from peripheral blood lymphocytes of a patient with familial amyloidotic polyneuropathy (FAP) and the transthyretin (TTR) gene examined for sequence mutations. Polymerase chain reaction was used to asymmetrically amplify the TTR exons. Direct DNA sequencing of the PCR product revealed a C for T mutation at the first base of codon 33 located in exon 2 of one transthyretin gene. This resulted in a substitution of leucine for phenylalanine at position 33. Exons 3 and 4 were examined and found to be normal. The mutation creates a novel DdeI restriction site at the point of the mutation.

Amyloidosis

Bone marrow transplantation in canine GM1 gangliosidosis.

Allogeneic bone marrow transplantation was carried out in an 81-day-old Portuguese water dog with GM1 gangliosidosis using a DLA identical sibling as donor. Engraftment was complete and beta-galactosidase activity in leukocytes of the transplanted dog were similar to those in the donor. Over the next 2.5 months neurological deterioration in the transplanted dog was similar to that in untreated dogs with GM1 gangliosidosis. Cerebral ganglioside GM1 concentrations were not diminished by bone marrow transplantation and cerebral beta-galactosidase activity was negligible. We conclude that allogeneic bone marrow transplantation early in life is ineffective in canine GM1 gangliosidosis.

Animals

Elderly peoples' experiences of discharge from hospital.

In a study of patients' perceptions of the transition from hospital to the community, 115 elderly people registered with a central London group practice were interviewed shortly after they arrived home. Many patients received little notice of discharge, a third being told on the day they left the hospital. A third felt they had been discharged too soon and those living alone were significantly less likely to return to a heated home containing basic items of food. Seventy-seven patients, including 80% of those living alone were visited by family, friends or professionals within three days of coming home. Eighty-six per cent of non-professional visitors were women. Several of the elderly couples appeared to be under considerable stress and not all individuals were receiving the help they considered most appropriate to their needs. Many of the problems identified were due to poor communication between practice, hospital and patients. We suggest several measures aimed at improving the quality of that communication, so as to ensure that available resources can be mobilized to support this vulnerable group of people.

Activities of Daily Living

Study of discharge communications from hospital doctors to an inner London general practice.

In inner London patients are now being discharged from hospital earlier to be cared for by the community services. In this study the general practitioners in one inner London practice were asked to evaluate discharge communications from hospital doctors. The general practitioners were dissatisfied with the delay in receiving over one third of the letters and with the content of almost a fifth. They also felt that delay and lack of detail affected their management in 24% of cases. They would have liked more information in the letters, particularly about drug regimens. Some suggestions for improvement in written discharge communications are made.

Communication

Denervation in the primary olfactory pathway of mice. IV. Biochemical and morphological evidence for neuronal replacement following nerve section.

Unilateral olfactory nerve section was performed in the mouse. Three biochemical markers of the olfactory chemoreceptor neurons: carnosine, carnosine synthetase activity and the olfactory marker protein, were measured in the olfactory bulb and epithelium. Parallel observations were made by light microscopy as well as at the ultrastructural level. The specific biochemical markers decrease rapidly in both bulb and epithelium and reach a minimum by the end of the first week after surgery. They then slowly return to 80% of control values by one month. Carnosinase activity in epithelium was essentially unaffected. These biochemical observations coincide temporally with the onset of degenerative changes seen morphologically, in both the bulb and epithelium. The degenerative changes persist for up to two weeks in the bulb and for about one week in the epithelium. At this time basal cell division and differentiation begins in the epithelium with subsequent regrowth of olfactory axons into the glomerular layer of the olfactory bulb with ther reappearance of olfactory axon terminals. The temporal coincidence of these biochemical and morphological observations suggests they are manifestations of the same process, and is consistent with the idea that the olfactory chemoreceptor neurons are perhaps unique in being able to be replaced from undifferentiated stem cells.

Animals

Denervation in the primary olfactory pathway of mice. III. Effect on enzymes of carnosine metabolism.

Carnosine (beta-Ala-L-His) is localized within the receptor neurons of the primary olfactory system. Carnosine synthetase, the enzyme responsible for its synthesis, is found in the primary olfactory pathway of the mouse at activities higher than that found in other body tissues and brain regions. Carnosinase, the degradative enzyme, is present at high activities, only in the olfactory epithelial portion of this pathway. Peripheral deafferentation or central denervation cause a selective decrease in the activity of carnosine synthetase in the reciprocal portion of the primary olfactory system implying specific localization within the receptor neurons. These data are consistent with a role for the dipeptide carnosine in olfactory neural transmission.

Animals

Intrauterine feeding of the growth retarded fetus: can we help?

Intrauterine feeding of the growth retarded fetus appears an attractive therapeutic possibility. However the factors which determine the reversibility of intrauterine growth retardation are poorly understood. While fetal substrate supply is the final common pathway by which many factors restrict fetal growth, improving fetal substrate supply does not always lead to improved fetal growth. Similarly, fetal substrate supply is an important regulator of fetal endocrine status, such as circulating IGF-1 levels, but again, improving fetal substrate supply does not always alter fetal endocrine status or fetal growth. The relationship between substrate supply, endocrine status and growth is regulated in a complex way by placental function. Understanding the role of the placenta in this regulation is essential if in the future we are to help the growth retarded fetus.

Embryonic and Fetal Development