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Biomedical subjects

J Wilson

Publications and source records attributed to J Wilson.

At least 631 records · Page 35Linked to original sources

Echocardiographic detection of ventricular septal defects in large animals.

Ventricular septal defects in a foal, a 2-year-old filly, and 2 calves were demonstrated with M-mode and two-dimensional real-time echocardiography. The studies were performed with the animals unsedated, either standing or in lateral recumbency. Cardiac windows were located between the 4th and 7th intercostal spaces, approximately at the level of the olecranon. In each case, the septal defect was visualized high in the membranous portion of the interventricular septum. Defects were visualized by use of sector scanning or linear-array ultrasonic equipment, with transducer frequencies of 2.25 to 3.5 MHz.

Animals↗

Concerted and predictable acquisition of glial fibrillary acidic protein filaments by a cohort of astroblasts in culture.

Primary cultures of the 21 day foetal rat brain contain a cohort of astroblasts that concertedly acquire glial fibrillary acidic protein (GFAP) filaments between the 16th and 18th hour after plating. This burst of cytoskeletal differentiation is not observed in cultures initiated from the 18 day foetal brain and is not effected by the addition of cytosine arabinoside, an inhibitor of glial cell proliferation.

Animals↗

Deafness in developing countries. Approaches to a global program of prevention.

The United Nations has adopted a strategic plan for the 1980s to prevent disabling conditions, primarily within the developing countries of the world. Currently, it is estimated that there are 450 million disabled people in the world and that hearing loss is one of the major disabling conditions within this group. The severity of this problem can be reduced by coordinated international planning and implementation of programs designed to reduce the impact of the various etiologic factors that are responsible for this problem.

Adult↗

Hypoglycemia masquerading as cerebrovascular disease (hypoglycemic hemiplegia).

Hypoglycemia produced hemiplegia with right-sided predilection in 16 patients initially suspected of having suffered a stroke. Fifteen patients had no demonstrable brain disease, and the hemiplegia cleared rapidly once the hypoglycemia was corrected. Invasive investigations such as carotid arteriography are not required in most patients. The features of hypoglycemia hemiplegia suggest that a selective neuronal vulnerability and not underlying focal brain disease is responsible in most cases.

Adult↗

Spore coat protein synthesis during development of Dictyostelium discoideum requires a low-molecular-weight inducer and continued multicellularity.

The major spore coat proteins of Dictyostelium discoideum are synthesized during the culmination stage of development. In an attempt to examine the regulatory mechanisms involved, spore coat protein synthesis by pseudoplasmodia harvested prior to culmination and incubated in submerged culture under various environmental conditions has been monitored. It is reported that the synthesis of spore coat proteins SP170, SP103, SP94, SP82, SP76, and SP55 is dependent upon the presence of a low-molecular-weight (Mr approx 100), heat-stable factor secreted by cells incubated at high density in buffer. Previous studies have implicated cyclic AMP, ammonia, and amino acids in spore cell differentiation. Partial purification of the spore coat protein inducing factor (SPIF), together with attempts to mimic its activity, indicate that SPIF is not identical with any of these molecules and it is probably also distinct from DIF and "fruit juice," two other factors which regulate the spore-stalk decision and the initiation of culmination, respectively, in D. discoideum. In addition to SPIF, the continued expression of the spore coat protein genes also requires that the integrity of the pseudoplasmodium be maintained. Unlike the expression of many other genes after aggregation, this latter requirement cannot be replaced by exogenous cyclic AMP. Termination of spore coat protein gene expression occurs despite the presence of excess exogenous SPIF and hence involves mechanisms other than the destruction or depletion of SPIF.

Age Factors↗

Reaction times to lateralized visual stimuli in callosal agenesis: stimulus and response factors.

A young acallosal man was intensively tested in a standard simple reaction time (RT) paradigm using briefly-presented lateralized spots for light. In Experiment 1, findings on previous acallosal patients of a large disadvantage for crossed (e.g. right hemifield-left hand) as against uncrossed (e.g. left hemifield-left hand) RTs were replicated. This crossed-uncrossed difference (CUD), as in previous work, turned out to be smaller in a bimanual response task than in the conventional unimanual task. Experiment 2 was a factorial study of unimanual RTs in which (a) stimulus intensity and (b) spatial S-R compatibility, were varied. As in a previously tested patient, decreased intensity resulted in a greatly increased CUD. S-R compatibility on the other hand had no effect on CUD. The results are interpreted as favouring a role for visual commissural neurones in the acallosal CUD, and as evidence against a spatial compatibility hypothesis.

Adult↗

Neuropathological studies in a child showing some features of the Rett syndrome.

Clinical and neuropathological data are presented from a girl who died at 14 yrs and who in life displayed some of the characteristics of the Rett syndrome--social withdrawal, progressive loss of locomotor as well as social skills, microcephaly, and a very restricted stereotypy of manipulation. Neuropathological studies showed mild generalised cerebral atrophy with marked unevenness of melanin deposition in nigral neurones. It is suggested that this patient may represent a severe form of the Rett syndrome.

Adolescent↗

Rett syndrome: criteria for inclusion and exclusion.

In the absence of discriminatory laboratory tests for accurate diagnosis of the Rett syndrome, the authors have tried to give as precise clinical criteria as possible for use particularly for research purposes.

Child↗

Dementia and depression among the elderly living in the Hobart community: the effect of the diagnostic criteria on the prevalence rates.

A survey was made of 274 non-institutionalized persons aged 70 and over living in Hobart. The prevalence of dementia and of depression was measured by interviewing subjects using a modified version of the Geriatric Mental State Schedule (GMS) (Copeland et al. 1976) and the Mini Mental State Examination (MMSE) (Folstein et al. 1975). Rates of morbidity were derived from different diagnostic procedures. These were: diagnoses made by a psychiatrist (A.S.H.) directly from the interview schedules and audiotapes, and rated as mild, moderate or severe; the criteria laid down in DSM-III, converted into algorithms describing 3 degrees of severity; and the algorithms for pervasive dementia and depression proposed by Gurland et al. (1983), and from these authors' rational scales. In addition, the relation between scales for dementia and for depression and the diagnosed categories was examined. Some problems in applying these methods to aged persons in the community are discussed. It is concluded that more detailed specification of criteria is desirable if the comparative epidemiology of dementia and depression in old age is to advance.

Aged↗

An inborn error of purine metabolism, deafness and neurodevelopmental abnormality.

A syndrome of hyperuricemia, sensorineural deafness, mild mental handicap and congenital disequilibrium in a four-year-old boy is probably inherited as a sex-linked condition since his mother has sensorineural deafness and similar biochemical abnormalities. There is evidence of a superactive PP-ribose-P synthetase, normal purine salvage enzymes, and severe depletion of nicotinamide adenine dinucleotide and guanine triphosphate in red cells.

Deafness↗

Isolation of a gene enhancer within an amplified inverted duplication after "expression selection".

We have attempted to isolate and identify cellular expression sequences from F9 teratocarcinoma DNA by utilizing their ability to reactivate a selectable gene devoid of its own expression sequences (expression selection). Restriction nuclease-digested F9 cellular DNA was ligated to a polyoma virus (Py) DNA fragment which contains an intact transforming region but is incapable of inducing transformation because it lacks the viral 5' enhancer sequence. The ligation mixture was used to transfect Rat-1 cells and a transformed cell line, 3B, was isolated. The 3B cell line contained a single type of Py DNA insert, which was molecularly cloned as an 18-kilobase BglII fragment. A weak cellular enhancer was identified in a 4.7-kilobase BamHI fragment upstream from the Py sequences. Both the Py DNA and the enhancer sequences were found to be present in an inverted duplication in the 3B clone. The presence of this structure in 3B genomic DNA was confirmed by the analysis of selectively isolated inverted duplicated sequences, and the structure was found to be at least 22 kilobases long. In the 3B cell line, the inverted duplicated sequences containing the Py and enhancer sequences are quite stable and are amplified 20- to 40-fold. The strongly transformed phenotype of the 3B cells may be a result of this amplification. The formation of inverted duplications as a part of the amplification mechanism as well as a general strategy for the cloning of inverted duplicated (amplified) sequences is discussed.

Animals↗

Oxygen flowmeters.

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Equipment Safety↗

Effect of lidamidine-HCl on Escherichia coli heat-stable enterotoxin-induced jejunal water and electrolyte secretion in neonatal piglets.

Neonatal piglets were anesthetized, and two jejunal loops, 20 cm in length, were prepared. Then, either water or 0.12, 0.25, 0.5 or 1.0 mg/kg of lidamidine-HCl was injected intraduodenally on a randomized basis, one treatment per pig. Following this, a crude heat-stable enterotoxin (ST) preparation produced from E. coli no. 1261 was injected into the proximal jejunal loop, and trypticase soy broth (TSB) (with osmolality adjusted to equal the enterotoxin preparation) was injected into the distal jejunal loop. Piglets remained anesthetized for 3 h and were then killed. Fluid was collected from the loops for measurement of volume and Na, K and Cl concentration. Empty loop lengths were measured. There was a significant dose-related reduction of volume and Cl content, and a dose-related, but not significant, reduction in Na content in St-treated loops. A comparison of the mean differences in responses between toxin- and TSB-treated loops indicated that the major 'counter-toxic' effect of the lidamidine was a dose-related increase in water and electrolyte absorption.

Animals↗

Use of interferon in the management of patients with subacute sclerosing panencephalitis.

Six patients (five male, one female) with subacute sclerosing panencephalitis were treated with purified lymphoblastoid interferon, using a combination of intravenous and lumbar intrathecal routes. The first symptoms of the disorder occurred between seven and 16 years of age, and the length of the illness before treatment varied from 1 1/2 to 12 months. All six patients were in the first clinical stage of the disorder. After a limited period of follow-up there has been no clinical improvement. Nil or low levels of interferon were found in CSF two hours after intravenous injection, but CSF levels of interferon were maintained for at least 24 hours after intrathecal injections. Side-effects of interferon included pyrexial reactions, especially after high-dose intravenous therapy (six), lethargy (four), a transient rise in blood pressure (two) and a reduction in platelet count (six). Staphylococcus epidermidis was grown from the CSF of one patient.

Adolescent↗

Multiple sclerosis in childhood: a new look.

Five patients (four female, one male) with multiple sclerosis were managed at the Hospital for Sick Children, London, between January 1978 and June 1983. The age at which first symptoms occurred varied from three to 14 years. Focal seizures occurred in three cases and an encephalopathic process in three cases, and there was evidence of progressive intellectual deterioration in all five children. Computed tomography showed low-density lesions in the white matter of all five. Electroencephalograms were abnormal in all cases, and in two the disturbance was severe. Oligoclonal bands were present in the cerebrospinal fluid of two children. Four of the five children had abnormal responses to pattern-reversal stimulus.

Adolescent↗

Congenital trypanosomiasis in a child born in London.

A female infant of 22 months was referred to the Hospital for Sick Children, London, because of delayed psychomotor development. Extensive investigations revealed no cause, but eventually trypanosomiasis was diagnosed. The infant had not been outside the UK, but her mother came from Zaire, where the disease is endemic, but had lived in Kinshasa, where there is no sleeping sickness. It is thought, that the mother may have been asymptomatically infected by a fresh-blood transfusion four years earlier, since no other source of infection was apparent.

Democratic Republic of the Congo↗