Search PubMed⌕ Search

Biomedical subjects

A Lawrence

Publications and source records attributed to A Lawrence.

At least 55 records · Page 3Linked to original sources
PubMed1994

A dissociation in the relation between memory tasks and frontal lobe tests in the normal elderly.

In this study a group of elderly subjects were examined on three tests of frontal lobe function. Two of these tests, FAS word fluency and the Alternate Uses Test, were considered tests of spontaneous flexibility, as defined by Eslinger and Grattan [Neuropsychologia 31, 17-28, 1993]. The third, the modified Wisconsin Card Sorting Test (WCST), is considered a test of reactive flexibility. Performance on two tests of memory, release from proactive interference (PI) and a matched recall and recognition test was also measured. The elderly were shown to be impaired on all tests when compared with young controls. Analysis revealed that release from proactive interference was significantly correlated with performance on alternative uses but not WCST while the size of subjects' discrepancy between recall and recognition correlated strongly with WCST but not with Alternate Uses. In addition there was a strong correlation between the two measures of spontaneous flexibility but these measures did not correlate with WCST. Performance on the two measures of memory was also uncorrelated. The data indicate that the pattern of frontal deterioration in the elderly does not comprise a single deficit and, furthermore, that the relationship between frontal dysfunction and normal age-related memory loss is not unidimensional.

Adult↗
PubMed1994

Complications of laparoscopic hysterectomy.

Although laparoscopic hysterectomy is now being performed worldwide, few reported data are available on the associated morbidity and mortality. Between December 1990 and September 1993, 220 women underwent laparoscopic hysterectomy at the Melbourne Gynoscopy Centre. Complications occurred in 35 (15.9%). Among these were anterior abdominal wall vessel injury in 5 patients, bladder injury in 5, febrile illness in 13, secondary hemorrhage in 4, temporary ureteral obstruction in 4, and Richter hernia in 1.

Abdominal Muscles↗
PubMed1994

Diffuse brain swelling after head injury: more often malignant in adults than children?

A series of 118 patients with diffuse traumatic brain swelling was studied retrospectively in order to compare the clinical findings in children with those in adults, and to determine the occurrence of neurological deterioration and outcome. The computerized tomography (CT) picture of absent third ventricle and basal cisterns was used to identify the cases. Although this condition has been associated with children, we found the same number of children and adults (59 cases each). Secondary deterioration (decline in consciousness, the development of new focal neurological signs, or an increase in intracranial pressure) occurred in 40% of cases and was more common in adults than children. Features that were significantly associated with deterioration were the presence of prolonged coma (> 1 hour) after the injury, CT signs of diffuse axonal injury or subarachnoid hemorrhage, or a recorded episode of hypotension. A moderate or good recovery at 6 months was achieved by 70 patients (59%), but 45 patients had a poor outcome (severe disability in nine, vegetative state in three, and death in 33) and this was often a consequence of secondary deterioration. In three patients, the outcome was not known. The combination of a severe initial injury, secondary insult, and diffuse swelling is associated with a poor outlook, particularly in adults. The CT appearance of diffuse swelling may develop more readily in children because of the lack of cerebrospinal fluid available for displacement. In children, diffuse swelling may have a relatively benign course unless there is a severe primary injury or a secondary hypotensive insult.

Adolescent↗
PubMed1993

Outer-membrane protein and immunoblot analysis of Australian isolates of Haemophilus influenzae.

Strains of Haemophilus influenzae isolated from children in South Australia and the Northern Territory with systemic infections (mostly meningitis or epiglottitis) were subjected to serotyping, biotyping, outer-membrane protein (OMP) analysis and immunoblot subtyping. All 65 isolates examined were from blood or cerebrospinal fluid; 59 (91%) of the strains were identified as type b and the remainder as either type a (two strains) or non-typable (four strains). Of the 59 type b strains, 45 (76%) belonged to a single OMP subtype (equivalent to subtype 3L in the Barenkamp scheme); the remaining type b strains belonged to five other OMP subtypes. No correlation was apparent between OMP subtype and geographical region, clinical diagnosis or antimicrobial drug susceptibility pattern. Immunoblot subtyping enabled nine (18%) of 41 strains belonging to the principal OMP subtype to be distinguished from the remainder.

Australia↗
PubMed1992

Polypeptide profiles of normal and inflamed rabbit aqueous humor: identification of catabolic products of immunoglobulin G in the normal eye.

The anterior segment of the eye is isolated from the bloodstream by anatomic barriers. These barriers break down during inflammation elicited by muramyl dipeptide (MDP), a component of the cell walls of bacteria. The protein composition of normal aqueous humor and inflamed aqueous were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. The presence of transferrin, albumin, IgG and IgM were demonstrated in normal and inflamed aqueous. Normal aqueous additionally contained seven polypeptides (35, 31, 29, 25, 22, 21 and 19 kDa, respectively) that were not observed in inflamed aqueous. Four of these peptides (31, 29, 25 and 19 kDa) were identified as fragments of IgG heavy chains based on their reactivity with anti-IgG antibodies and staphylococcal protein A. Immunoglobulin catabolism has been noted to occur in tissues diffusely throughout the body; this is the first report of it occurring in the eye. This phenomenon appears to be circumvented on breakdown of the blood-aqueous barrier. These observations may relate to the immunoprivilege of the eye and its modulation in inflammation.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1992

Morphine metabolism in neonates and infants.

The metabolism of morphine was studied in seven fullterm neonates and five infants receiving a continuous infusion of morphine. All the patients had detectable plasma concentrations of morphine 3-glucuronide (M3G) and 10 had detectable concentrations of morphine 6-glucuronide (M6G). The mean plasma clearance of morphine was 20.1 ml min-1 kg-1 in neonates and 23.4 ml min-1 kg-1 in the group as a whole. The M3G/morphine ratio (7.3) was higher than that previously reported for preterm neonates (5.0) but lower than that reported for children (23.9).

Chromatography, High Pressure Liquid↗
PubMed1992

Indications for and accuracy of magnetic resonance imaging and computed tomography in orbital disease.

All patients referred for orbital imaging to the neuroradiology department of the Institute of Neurological Sciences in Glasgow over a three year period were enrolled in the study and were scheduled to undergo both magnetic resonance imaging and computed tomography. A total of 101 of the 110 referred patients were deemed suitable for analysis. Details of key presenting symptoms, signs, and a pre-imaging diagnosis were recorded prospectively. A final diagnosis was obtained by histology in 65% of cases with an orbital abnormality, by a minimum of one year of clinical review in 19.5%, by response to antibiotic or steroid therapy in 8.5%, or by conclusive investigations such as carotid angiography in in 7% of patients, 29% of the patients had no detectable orbital disease despite a minimum one years' follow-up, and so were regarded as a "normal" group. The images were interpreted prospectively by separate masked observers. The diagnostic accuracies of the two techniques were compared to the final diagnosis. The two imaging methods were shown to be comparable in overall diagnostic accuracy, with a small and statistically non-significant advantage held by magnetic resonance imaging. Interpretation of the two investigations gave more accurate information in different types of disease.

Academies and Institutes↗
PubMed1992

The effect of "binge" ethanol exposure on growth hormone and prolactin gene expression and secretion.

The effects of ethanol (EtOH) on GH and PRL have been previously explored, and a dicotomy in results noted. While serum GH levels appear to fall after EtOH exposure, PRL levels rise. We have attempted to expand these studies by examining the impact of acute or "binge" EtOH in vivo on GH and PRL synthesis and secretion. At 0.5, 1.5, and 3.0 h after one dose of ip EtOH, serum GH levels fell significantly compared with those seen in saline-injected controls. This correlated with a fall in GH mRNA levels, but no change in pituitary GH content. Conversely, serum PRL levels rose significantly, while the mRNA for PRL decreased by approximately 20%. There was no change in pituitary PRL content. Interestingly, the mRNA for pit-1 (GHF-1), a transcription factor important to both GH and PRL gene expression, was unchanged at any time point. Despite the fall in GH and PRL mRNA levels, the pituitary cAMP content was markedly elevated at 0.5 h, with no change at any other time point. In summary, acute EtOH exposure in vivo appears to dampen both GH and PRL synthesis, while serum levels behave dissimilarily. Possible explanations for these findings are discussed.

Alcoholism↗
PubMed1991

Semi-quantitative assay of D antigen site density by flow cytometric analysis.

This study describes the comparative measurement of D antigen site density using a fluorescent indirect antiglobulin test (FIAT) read by flow cytometry. The test results confirmed the continuum of D antigen strength from weakest D through to R2R2 and also allowed the majority of weak D samples to be adequately distinguished from D-negative samples.

Erythrocytes↗
PubMed1991

Current perception threshold in evaluating foot pain. Two case presentations.

Two cases are reported in which patients presented with complaints of foot pain, and a clinical suspicion of radiculopathy was supported by current perception threshold testing. Chiropractic manipulation of the lumbar spine resulted in alleviation of the lower extremity symptoms. Current perception threshold testing is a valuable neurologic testing modality that is noninvasive, nonaversive, and highly reliable for evaluation of sensory nerves where neuropathy is suspected. This technology has been described for evaluation of diabetic neuropathy, uremic screening, and alcohol and chemical toxicity. Additionally, current perception threshold is useful for evaluation of other neuropathies, such as carpal tunnel syndrome and other entrapment neuropathies. The authors encourage further investigation of this modality in the diagnosis and evaluation of peripheral neuropathy and unexplained foot pain secondary to spinal nerve impingement.

Adult↗
PubMed1989

Comparison of magnetic resonance imaging and computed tomography in suspected lesions in the posterior cranial fossa.

OBJECTIVE: To compare computed tomography and magnetic resonance imaging in investigating patients suspected of having a lesion in the posterior cranial fossa. DESIGN: Randomised allocation of newly referred patients to undergo either computed tomography or magnetic resonance imaging; the alternative investigation was performed subsequently only in response to a request from the referring doctor. SETTING: A regional neuroscience centre serving 2.7 million. PATIENTS: 1020 Patients recruited between April 1986 and December 1987, all suspected by neurologists, neurosurgeons, or other specialists of having a lesion in the posterior fossa and referred for neuroradiology. The groups allocated to undergo computed tomography or magnetic resonance imaging were well matched in distributions of age, sex, specialty of referring doctor, investigation as an inpatient or an outpatient, suspected site of lesion, and presumed disease process; the referring doctor's confidence in the initial clinical diagnosis was also similar. INTERVENTIONS: After the patients had been imaged by either computed tomography or magnetic resonance (using a resistive magnet of 0.15 T) doctors were given the radiologist's report and a form asking if they considered that imaging with the alternative technique was necessary and, if so, why; it also asked for their current diagnoses and their confidence in them. MAIN OUTCOME MEASURES: Number of requests for the alternative method of investigation. Assessment of characteristics of patients for whom further imaging was requested and lesions that were suspected initially and how the results of the second imaging affected clinicians' and radiologists' opinions. RESULTS: Ninety three of the 501 patients who initially underwent computed tomography were referred subsequently for magnetic resonance imaging whereas only 28 of the 493 patients who initially underwent magnetic resonance imaging were referred subsequently for computed tomography. Over the study the number of patients referred for magnetic resonance imaging after computed tomography increased but requests for computed tomography after magnetic resonance imaging decreased. The reason that clinicians gave most commonly for requesting further imaging by magnetic resonance was that the results of the initial computed tomography failed to exclude their suspected diagnosis (64 patients). This was less common in patients investigated initially by magnetic resonance imaging (eight patients). Management of 28 patients (6%) imaged initially with computed tomography and 12 patients (2%) imaged initially with magnetic resonance was changed on the basis of the results of the alternative imaging. CONCLUSIONS: Magnetic resonance imaging provided doctors with the information required to manage patients suspected of having a lesion in the posterior fossa more commonly than computed tomography, but computed tomography alone was satisfactory in 80% of cases...

Brain Diseases↗
PubMed1989

Getting back to dental practice.

The results from the survey 'The Provision of Dental Care by Women Dentists in England and Wales in 1985' indicated that the lack of a specific retraining course was a major barrier in preventing women who have left dental practice from returning to work. The need for a course also applied to men and women who have ceased to work because of ill-health.

Curriculum↗
PubMed1989

High resolution of honey bee (Apis mellifera) venom peptides by propionic acid/urea polyacrylamide gel electrophoresis after ethanol precipitation.

A new and simple gel electrophoretic method is described which enables the protein and polypeptide components of bee venom to be resolved on a single gel. The electrophoretic method allows octapeptides to be resolved and species as small as decapeptides can be detected at high sensitivity using the Coomassie blue staining method without prior fixation. This has been achieved by replacing acetic acid by propionic acid in acid/urea polyacrylamide gels and by controlling the amount of TEMED catalyst for the polymerisation of high concentration gels in order to obtain a low effective pore size. We demonstrated the value of ethanol precipitation as a rapid and efficient desalting the fractionation technique and propose that it could be used in combination with gel filtration to purify many of the peptides to homogeneity.

Animals↗
PubMed1989

The efficacy and toxicity of azidothymidine (AZT) in the treatment of patients with AIDS and AIDS-related complex (ARC): an open uncontrolled treatment study.

The efficacy and toxicity of oral azidothymidine has been studied in 145 patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC). The median survival time of AIDS patients on azidothymidine was 4.5 times higher when compared to a historical AIDS group who had not received the drug. This result must be interpreted with caution because of changes in treatment of HIV infection and growing awareness of AIDS which may have led to earlier diagnosis in the group treated with azidothymidine. The mortality was significantly higher in those patients who received transfusions and was particularly high in those who were transfused before azidothymidine. There was a significant difference in the occurrence of opportunistic infections in the patients who received transfusions compared with those who did not. AIDS patients treated immediately after an episode of Pneumocystis carinii pneumonia survived significantly longer than those in whom treatment was delayed for three months or more, and longer than those who were treated with azidothymidine because of another opportunistic infection or Kaposi's sarcoma. The T4 cell median counts increased in patients treated with azidothymidine reaching a peak at the end of the fourth month of treatment in the ARC group and at the end of the first month in the AIDS group with a subsequent fall in both groups. Sixty per cent of patients were p24 viral antigen positive at the start of treatment and 19 per cent of these patients had a fall of more than 50 per cent in antigen level while 32 per cent became antigen negative following treatment with azidothymidine. The mortality in the patients where the antigen disappeared or in whom there was a major fall of more than 50 per cent in antigen level was significantly less than in those where there was no change in antigen level. Twenty-nine patients were treated with azidothymidine because of skin Kaposi's sarcoma and in 17 tumour regressed or was stable. Thirty-two per cent of patients treated with azidothymidine became anaemic. Neutropenia occurred in 3 per cent of patients. Platelets increased initially after treatment but subsequently fell to thrombocytopenic levels in eight patients. Nine of 12 patients with thrombocytopenia before azidothymidine was commenced responded with an increased platelet count.

AIDS-Related Complex↗