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Biomedical subjects

P Jennings

Publications and source records attributed to P Jennings.

At least 37 records · Page 2Linked to original sources
PubMed1992

Phonological behavior in toddlers with slow expressive language development.

Toddlers with slow expressive language development were compared to normally speaking age-mates on three global measures of phonological behavior: the average level of complexity of their syllable structures, the number of different consonant phonemes produced, and the percentage of consonants correctly produced in intelligible utterances. The groups were found to differ significantly on all three variables. Further analyses were done, breaking the groups down into narrower age ranges. These comparisons also revealed differences between late-talking and normal youngsters. Detailed analyses of the range of phonemes and syllable structures produced, as well as the appearance of phoneme classes within syllable structures and positions, revealed that late talkers showed a delayed rather than a deviant pattern of phonological development. The implications of these findings for identifying and monitoring expressive delay in toddlers are discussed.

Articulation Disorders↗
PubMed1992

Portable chest radiography in intensive care: a comparison of computed and conventional radiography.

A prospective study was performed comparing computed and conventional radiography for the detection and visibility of cardiovascular devices in intensive care unit patients. Computed images were obtained using a commercially available 2K x 2K, 12-bit storage phosphor plate system. Image sets from 50 patients were assessed independently by three observers. A significant difference between the types of image was found for the detection of mediastinal drainage tubes and prosthetic valves. Computed images allowed greater confidence in the identification of courses and tips of lines. This advantage was most marked with edge-enhanced computed images.

Adult↗
PubMed1992

Na+ effects on intracellular pH of isolated, perfused rabbit gastric mucosal surface cells.

The effects of extracellular Na+ on intracellular pH were studied by perfusing BCECF loaded gastric mucosal surface cells adherent to glass coverslips held in a spectrophotofluorometer. Removal of Na+ from a NaCl Ringer perfusate (pH 7.4) resulted in progressive intracellular acidification, which was partially blocked by amiloride. An H+ conductance did not appear to be present. Acidification induced either by Na+ removal or by a NH4 prepulse was reversed by extracellular Na+, but this effect was not completely prevented by amiloride. Amiloride significantly, but not completely, inhibited Na22 uptake by gastric mucosal surface cells. The data suggest that extracellular Na+ maintains intracellular pH of gastric mucosal surface cells through amiloride-sensitive and -insensitive pathways. In the absence of extracellular Na+, cellular acidification seemed to be partially due to Na+/H+ exchange.

Amiloride↗
PubMed1991

Comparative accuracy of high resolution computed tomography and chest radiography in the diagnosis of chronic diffuse infiltrative lung disease.

One hundred individuals who had undergone both high resolution computed tomography (HRCT) and chest radiography were studied to determine the accuracy of each technique in establishing the diagnosis of diffuse lung disease. The group consisted of 86 patients with a diagnosis of a chronic diffuse infiltrative lung disease and 14 normal subjects. Two independent observers assessed the HRCT examinations and chest radiographs and recorded the three most likely diagnoses. Overall a confident diagnosis was reached more often with HRCT (49%) than with chest radiography (41%). The diagnoses were correct in 82% of HRCT examinations and 69% of chest radiographs. Diagnoses made on HRCT, irrespective of the degree of certainty, were accurate more often than diagnoses made on chest radiography (56% and 47% respectively). Of the patients thought to have a normal chest radiograph, 42% had diffuse infiltrative lung disease (DILD). Of the patients thought to be normal on HRCT, 18% had DILD. Conversely, normal subjects were correctly identified as such in 82% of chest radiographs and in 96% of HRCT examinations. This study emphasizes the important role of CT in helping to confirm or refute the presence of abnormality when the chest radiograph is normal or questionably abnormal, and underlines the superior diagnostic accuracy of HRCT compared with conventional chest radiography in DILD.

Chronic Disease↗
PubMed1990

The effect of intermittent local heating on fracture healing in the distal tibia of the rabbit.

Two series of controlled experiments were carried out to investigate the effect of intermittent local heating on fracture healing in the distal tibia of the rabbit. In the first series, the distal tibia was fractured in a reproducible manner and then treated by compression plate fixation. Nine animals received intermittent local heating around the fracture site for 6 weeks postoperatively in comparison with 5 control animals. The mechanical strength of the healed tibia was then measured in a standardized 3-point bend test. Intermittent local heating produced stronger bones than the untreated controls in 6 of the 9 cases, a result which was marginally significant (P = 0.055). In the second series of experiments, a reproducible bone defect was created by drilling a 2 mm diameter hole through the distal tibia; compression plate stabilization was not required. Fourteen animals received intermittent local heating around the fracture site for 3 weeks postoperatively in comparison with 7 control animals. Intermittent local heating produced stronger bones than the untreated controls in 8 of the 14 cases, a result which was not significant (P greater than 0.1). It is concluded that intermittent local heating of the type studied has too small an effect on accelerating the rate of fracture repair to be clinically useful.

Animals↗
PubMed1990

Retroperitoneal metastases from carcinoma of the bladder.

We report two patients of metastatic retroperitoneal tumours from carcinoma of the bladder, one presenting with a retroperitoneal mass and the other with retroperitoneal fibrosis. Both cases had been previously treated by radiotherapy for invasive transitional cell carcinoma of the bladder and had no evident of recurrent tumour in the bladder during follow up or at the time of presentation with secondary tumours. Literature reviews revealed that urothelial tumours from the bladder rarely metastasize to the retroperitoneal space.

Carcinoma, Transitional Cell↗
PubMed1988

Nucleic acid flow cytometry in large cell lymphoma.

Between 1978 and 1985, 140 patients with large cell lymphoma (27 follicular, 92 diffuse, 5 immunoblastic, and 16 transformed) had DNA-RNA cytometry performed on involved tissue. DNA-RNA features were correlated with treatment outcome and compared to other established prognostic factors in 63 newly diagnosed patients who received uniformly intensive therapy. Significantly better outcome was noted for previously untreated patients with intermediate RNA content (RNA index, 1.0-1.8), diploid DNA content, and (during the initial 12-month follow-up) low proliferative activity. Of patients followed beyond 12-24 months, those with high proliferative activity appeared to have the most durable remissions, although this was not statistically significant. These findings suggested a preferential impact of intensive chemotherapy on patients with intermediate RNA content and possibly those with high proliferative activity, since previous studies and our own experience with relapsing patients have indicated a progressively worse outlook with higher proliferative activity and RNA index values. In newly diagnosed patients, multivariate analysis identified RNA content as the most important prognostic factor, followed by proliferative activity and serum lactate dehydrogenase. Thus, for patients with large cell lymphoma, DNA-RNA cytometry appears to be a valuable prognostic parameter for identifying a subset of patients who have a high likelihood of cure with intensive chemotherapy.

Analysis of Variance↗
PubMed1987

Determination of the aryltetralin lignan content of podophyllum resins and roots/rhizomes.

A simple, quantitatively reproducible method for determining the aryltetralin lignan content of the resins and roots/rhizomes of Podophyllum hexandrum and P. peltatum is described. The method confirms that P. hexandrum resins and roots/rhizomes contain approximately four times the quantity of lignans as do those of P. peltatum and also that there is a significant variation in the lignan content of P. hexandrum resins.

Chromatography, Thin Layer↗
PubMed1984

Use of P300 and a dementia rating scale in the evaluation of cognitive dysfunction in MS.

The assessment of mental dysfunction in multiple sclerosis and discrimination from the secondary effects of sensory and motor deficits has comparability to similar work done on dementia in Alzheimer's disease and Parkinson disease. Two approaches to testing might include adaptation of the Alzheimer Disease Assessment Scale and inclusion of the P300 component of the event-related auditory evoked potential.

Alzheimer Disease↗
PubMed1983

Effects of nitrous oxide-induced inactivation of cobalamin on methionine and S-adenosylmethionine metabolism in the rat.

Inhalation of nitrous oxidises cobalamin and, in turn, inactivates methionine synthetase which forms methionine from homocysteine and which requires cob[I]alamin as a co-factor. This study was planned to determine the effect of virtual cessation of methionine synthesis via a cobalamin-dependent pathway, on tissue levels of methionine, S-adenosylmethionine and on related enzymes. The level of methionine in liver fell initially after exposure to N2O but was restored to pre-N2O levels after 6 days despite continuing N2O exposure. Brain methionine fell within 12 h of N2O exposure but the fall was not significant. The restoration of methionine levels is accompanied by an increase in activity of betaine homocysteine methyltransferase in liver but this enzyme was not detected in brain. The activity of methionine synthetase remained very low in both liver and brain as long as N2O inhalation was continued. There was an initial rise in liver S-adenosylmethionine levels followed by a steady fall to 40% of its initial level after 11 days of N2O exposure. However, there was no change in the level of S-adenosylmethionine in brain during this period. The data indicate that either brain meets its requirement by increased methionine uptake from plasma or that there are alternate pathways in brain for methionine synthesis other than those requiring a cobalamin coenzyme.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1981

The effect of nitrous oxide-induced inactivation of cobalamin on plasma amino acid levels in the rat.

Rats were maintained in an atmosphere of equal volumes of oxygen/nitrous oxide (1/1) for up to 7 d and plasma levels of methionine, glycine, serine, histidine, homocysteine and S-methylcysteine were measured. There was a fall in plasma methionine and a rise in plasma serine levels. There were no significant changes in glycine and histidine levels. Homocysteine and S-methylcysteine were not detected in rat plasmas. The fall in plasma methionine was due to loss of cobalamin-dependent methionine synthetase activity. The rise in plasma serine may be due to decline in its metabolism via methenyltetrahydrofolate cyclohydrolase which is concerned in oxidizing the methenyl-carbon ( =CH-), initially derived as a methylene-carbon (-CH2-)from serine, to formate (-CHO).

Amino Acids↗
PubMed1976

Tension pneumothorax: a teaching model.

A TPT induced in a small rabbit is an excellent teaching model for the treatment of a TPT in the small human neonate. Pediatric housestaff, neonatal nurses, and others have utilized this model to gain confidence and expertise in the diagnosis and treatment of TPT. The rabbit model is inexpensive, readily available, and recreates the clinical condition of a TPT in an educational environment.

Animals↗