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Biomedical subjects

T Johnson

Publications and source records attributed to T Johnson.

At least 145 records · Page 8Linked to original sources
PubMed1996

Safety of imaging exploding bullets with ultrasound.

STUDY OBJECTIVE: To evaluate the safety of using ultrasound to image exploding bullets that have not detonated. METHODS: We evaluated various types of exploding bullets using ultrasonography at various depths with various transducers and using standard radiography. RESULTS: None of the unexploded bullets subjected to ultrasonography or standard radiography exploded. CONCLUSION: Our results suggest that evaluation of exploding bullets with ultrasonography is safe.

Explosions↗
PubMed1996

The cost of treatment of psychiatric emergencies: a comparison of hospital and community services.

This study aimed to compare the costs of treatment by community-based and hospital-based psychiatric services. The design entailed random allocation of patients presenting with psychiatric emergencies over a subsequent 3-month period to one of two services, followed by retrospective quantification of service use and its cost for each group. One hundred patients with emergency presentations to the psychiatric service via the Accident and Emergency Department, liaison psychiatrist and approved social worker were included in the study. Their use of a range of terms of service was recorded and disaggregated costings of these items of service was calculated. The use of non-psychiatric services was similar for both groups, but the use of psychiatric services differed, with the hospital group making greater use of in-patient beds and the community group employing more frequent home-based interventions. The total cost of treatment for the community group (pound 56,000) was much lower than for the hospital group (pound 130,000), although the median patient cost was 50% higher in the community group (pound 938 v. pound 610), and a greater proportion of the community service expenditure (10% v. 2%) was due to failed contacts. Taken together with clinical outcome, which showed no advantages for the hospital-based service over the community-based service, our findings suggest that this form of community psychiatric service is a cost-efficient alternative to hospital-based care for this group of patients.

Adult↗
PubMed1996

Anti-neutrophil cytoplasmic antibodies (ANCA) directed against bactericidal/permeability increasing protein (BPI): a new seromarker for inflammatory bowel disease and associated disorders.

It was our purpose to determine the immunodiagnostic value of ANCA directed against BPI in diseases known to be associated with ANCA, such as ANCA-associated vasculitides, inflammatory bowel disease (IBD) and the associated condition primary sclerosing cholangitis. The immunoreactivity of recombinant PBI (rBPI) was established in order to develop an ELISA specific for rBPI. By means of this assay, BPI-ANCA were assessed in sera of 178 patients with IBD or the associated disorder primary sclerosing cholangitis, 112 patients with ANCA-associated vasculitides, and in sera of 182 disease and 140 health controls. BPI-ANCA were found to be closely associated with IBD and primary sclerosing cholangitis (34% and 44% of ANCA-positive sera, respectively). By contrast, BPI-ANCA positivity was low (<10%) in the double-negative sera of patients with ANCA-associated vasculitides and in disease and health controls. BPI-ANCA appear to constitute an important marker for IBD and primary sclerosing cholangitis, but not for the ANCA-associated vasculitides.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1996

Outcomes after seizure recurrence in people with well-controlled epilepsy and the factors that influence it. The MRC Antiepileptic Drug Withdrawal Group.

PURPOSE: To determine the risk of further seizures and probability of further remission after a first seizure recurrence in patients in remission of their epilepsy, and to examine the prognostic factors influencing this risk. METHODS: Continued follow-up of a cohort of 409 patients with a recurrence of seizures after randomization to the Medical Research Council (MRC) Antiepileptic Drug Withdrawal Study. RESULTS: By 3 years after a seizure, 95% of patients have experienced a further 1-year remission of their epilepsy and by 5 years 90% of patients have experienced a further 2-year remission. The most important factors contributing to the risk of further seizures after a first seizure after randomization were the previous seizure-free interval, having partial seizures at recurrence, and having previously experienced seizures while receiving treatment. There was no evidence that the group of patients who had discontinued or reduced treatment before the occurrence of their first seizure after randomization had a different outcome from those patients who continued treatment. CONCLUSION: Our results provide no evidence that discontinuation of antiepileptic drugs (AEDs) modifies the long-term prognosis of a person's epilepsy, although it does increase the risk of seizures in the 1- to 2-year period after discontinuation.

Adolescent↗
PubMed1996

Risk of accidents in drivers with epilepsy.

OBJECTIVE: To estimate the risks of road traffic accidents over a period of three years in drivers with a history of single seizures or epilepsy, and to compare them with a cohort of drivers followed up by the Transport Research Laboratory (TRL). DESIGN: A retrospective survey of driving and accident experience by self-completion questionnaire. SUBJECTS: 16,958 drivers with a previous history of epilepsy responding to the survey and 8888 non-epileptic drivers responding to a TRL survey. MAIN OUTCOME MEASURES: The risk of any accident, any accident producing an injury, and any accident producing a serious injury, over a three year period. RESULTS: After adjustment for differences in age, sex, driving experience, and mileage between the two populations there was no evidence of any overall increase in risk of accidents in the population of drivers with a history of epilepsy. However, there was evidence of an increased risk of more severe accidents in the population with epilepsy. The risk was increased by about 40% for serious injuries and there was evidence of a twofold risk of increase in non-driver fatalities. These increases seem largely explicable by the occurrence of seizures in this population during the three years of driving that the survey covered. CONCLUSIONS: The acceptability of driving for people with a history of epilepsy should be determined by an acceptable risk of accidents resulting in injury or serious injury rather than overall accident rates. As people with epilepsy can now drive after a 12 month seizure free period rather than the required two year period when this survey was undertaken, it is important to ascertain whether there is any increased risk of injury associated accidents with this policy.

Accidents, Traffic↗
PubMed1996

Angiotensin converting enzyme expression in primary pulmonary hypertension.

We compared immunoreactivity for angiotensin converting enzyme (ACE) in pulmonary artery and lung parenchymal tissues (obtained at the time of resection for lung transplantation) from eight patients with Stage IV primary pulmonary hypertension (PPH) with the reactivity in similar tissues from eight normal donors. ACE immunoreactivity was markedly and consistently increased in the endothelium and subendothelial neointimal regions of elastic pulmonary arteries from patients with PPH as compared with normal pulmonary arteries. Immunoreactivity in normal muscular pulmonary arteries was usually less than in surrounding capillary endothelial cells, whereas it was usually of comparable intensity with that in surrounding alveolar capillaries in muscular pulmonary arteries of patients with PPH. These observations suggest that ACE may be involved in the pathogenesis of vascular remodeling associated with neointimal formation in pulmonary arteries.

Case-Control Studies↗
PubMed1996

Establishing the severity of personality disorder.

OBJECTIVE: The authors developed a simplified method of rating the severity of personality disorder. METHOD: The new rating method is based on four levels of severity: no personality disorder, personality difficulty, simple personality disorder, and diffuse personality disorder. The new method was applied to different diagnostic systems and was then compared with an old rating system based on six severity levels. Data were derived from a longitudinal study in which 163 patients with anxiety and depressive disorders had initial assessments of personality status and were followed up over 2 years. Ratings of psychiatric symptoms were made by using the Comprehensive Psychopathological Rating Scale over this period. The results were analyzed with special attention to linear and quadratic trends. RESULTS: The new system was clinically useful in separating patients' initial assessments and outcomes. Patients with no personality disorder had the lowest initial symptom scores and the best outcomes, and those with diffuse personality disorder had the highest initial levels of symptoms and improved least over the 2 years. When the patients were separated by the old classification system, 72% of the variation between groups was accounted for by linear and quadratic trends; the comparable percentage was 97% when the patients were categorized by the new system. CONCLUSIONS: The new system of rating severity of personality disturbance is an improvement on existing methods and allows ratings to be made easily from DSM-IV and ICD-10.

Humans↗
PubMed1996

Quantitation of epidermal nerves in diabetic neuropathy.

We describe methods to quantify epidermal nerve fibers (ENFs) in skin biopsy specimens from diabetic candidates for pancreas transplantation and control subjects. ENFs and the dermal-epidermal basement membrane were stained by immunohistochemical methods, imaged with a confocal microscope, and quantified using a neuron tracing system. The number of ENFs per surface of epidermis was diminished in diabetic subjects. ENF number and summed length of all ENFs per volume of epidermis examined were also decreased. Length and number of branch points of single surviving ENFs were similar in skin of control and diabetic subjects. The methods and results constitute a basis for continued study of the effects of the euglycemia that attends successful pancreas transplantation and the effects of therapy in patients with various types of polyneuropathy.

Cell Count↗
PubMed1996

Autonomous differentiation in the mouse myogenic cell line, C2, involves a mutual positive control between insulin-like growth factor II and MyoD, operating as early as at the myoblast stage.

We have studied the contribution of the endogenous production of insulin-like growth factor II (IGFII) and of the muscle regulatory factor, MyoD, to the autonomy of differentiation in isolated skeletal myoblasts. Inhibition of MyoD and IGFII gene expression in myoblasts of the mouse myogenic cell line, C2, was achieved by transfection and selection of stably transfected cells (anti-MyoD and anti-IGFII cells) with vectors producing MyoD or IGFII antisense RNA. We observed that inhibiting either MyoD or IGFII has multiple and similar consequences. In addition to the inhibition of the target gene, expression of MyoD transcripts in anti-IGFII myoblasts and expression of IGFII in anti-MyoD myoblasts were also abolished, whereas accumulation of transcripts for the muscle regulatory factor, Myf5, was markedly increased in both cell types. However, despite this Myf5 up-regulation, both anti-IGFII and anti-MyoD myoblasts lost the ability to undergo autonomous differentiation (differentiation in the absence of added IGF), further indicating that Myf5 and MyoD are not strictly interchangeable. Additional evidence of a link between MyoD and IGFII was obtained: (1) forced expression of the MyoD cDNA stimulated IGFII gene expression, and (2) treatment of C2 myoblasts with fibroblast growth factor, not only diminished MyoD expression and compromised differentiation as previously shown by others, but also abolished IGFII expression. These experiments showing loss or gain of function argue in favor of a mutual positive control between IGFII and MyoD operating as early as the myoblast stage.

Animals↗
PubMed1996

Axonemal tubulin polyglycylation probed with two monoclonal antibodies: widespread evolutionary distribution, appearance during spermatozoan maturation and possible function in motility.

Two monoclonal antibodies, AXO 49 and TAP 952, probed with carboxy-terminal peptides from Paramecium axonemal tubulin and with polyglycylated synthetic peptides, are found to recognize differently tubulin polyglycylation, the most recently identified posttranslational modification discovered in Paramecium axonemal tubulin. With these antibodies, we show that tubulin polyglycylation is widely distributed in organisms ranging from ciliated protozoa to mammals; it arose early in the course of evolution, but seems to be absent in primitive protozoa such as the Euglenozoa. Tubulin polyglycylation is the last posttranslational modification which takes place in the course of Drosophila spermatogenesis and its occurrence corresponds to the end of spermatozoan maturation. An involvement of polyglycylated tubulin in axoneme motility is suggested since AXO 49 and TAP 952 specifically inhibit the reactivated motility of sea urchin spermatozoa.

Amino Acid Sequence↗
PubMed1996

Young black males and trauma: predisposing factors to presentation in an urban trauma unit.

Young black males are disproportionately represented as patients in trauma units. Unemployment, low educational level, and family composition may predispose young black males to trauma unit admission. To test this hypothesis, 300 males between the ages of 18 and 40 admitted to the Cook County Hospital Trauma Unit were surveyed with respect to demographic data, family composition, educational level, and employment background. The majority of patients were black (87%) and unemployed (68%). The most common diagnoses were penetrating trauma (53.2%) and assault (33.5%). Highest unemployment and lowest educational levels were found among patients who were victims of penetrating trauma or assault. Sixty-six percent reported the presence of an adult male in the household while growing up, and 93% reported the consistent presence of their biological mother. There was a significant correlation between race, trauma mechanism, unemployment, low educational level, and family composition. Recognition and amelioration of the economic and educational inequities that may exist in this population might reduce the incidence of trauma significantly.

Adolescent↗
PubMed1996

Cryopreservation of rat and mouse hepatocytes. II. Assessment of metabolic capacity using testosterone metabolism.

Cryopreservation of hepatocytes is widely used, but to validate the use of cryopreserved (CP) hepatocytes in metabolic studies, CP cells must compare favorably with fresh cell activities. We have assessed the metabolic capacity of fresh and CP rat and mouse hepatocytes in primary culture. Total cytochrome P450 (P450) contents and metabolism of testosterone were measured up to 72 hr in culture. At 0 hr, total P approximately 450 in CP rat hepatocytes was 102.5 +/- 32.8 pmol/10(6) cells, compared with fresh rat hepatocytes that had 148.2 +/- 75.7 pmol/10(6) cells. The P450 contents of mouse hepatocytes were also unaltered by cryopreservation (176.7 +/- 56.0 pmol/ 10(6) fresh cells; 196.4 +/- 59.9 pmol/10(6) CP cells). There were no significant differences in the total P450 contents of fresh and CP rat and mouse cell cultures with time over 72 hr in culture. The overall metabolism of testosterone was lower in CP suspensions than in freshly isolated hepatocytes. When CP hepatocyte suspensions were permeabilized (with digitonin) and incubated with NADPH and ATP, testosterone metabolism was significantly increased. Testosterone hydroxylase activities (16 alpha-, 6 beta-, 2 alpha-, and 7 alpha-hydroxylase) were equivalent in fresh and CP rat hepatocytes over 72 hr in culture. There was a marked and sustained loss of 6 beta-hydroxylase activity in CP mouse hepatocyte cultures, compared with fresh hepatocytes throughout 72 hr in culture (436.9 +/- 118.0 pmol/min/10(6) cells and 37.3 +/- 41.0 pmol/min/10(6) cells at 72 hr in fresh and CP mouse hepatocytes, respectively). The total metabolism of testosterone was, however, unaffected because 16 alpha-hydroxylase activity increased in CP mouse hepatocytes (475.4 +/- 80.8 pmol/min/10(6) CP cells, compared with 148.7 +/- 39.4 pmol/min/10(6) fresh cells).

Adenosine Triphosphate↗
PubMed1995

High-dose 90Y Mx-diethylenetriaminepentaacetic acid (DTPA)-BrE-3 and autologous hematopoietic stem cell support (AHSCS) for the treatment of advanced breast cancer: a phase I trial.

This Phase I trial explores the use of high-dose 90Y conjugated to the antibreast cancer monoclonal antibody BrE-3 and autologous hematologic cell support in the treatment of women with stage four breast cancer. Nine women with heavily pretreated disease were enrolled. All of the patients had BrE-3-positive tumors by immunostaining and were treated with increasing doses of 90Y (15 mCi/m2, 3 patients), 20 mCi/M2 (six patients), and a fixed (50 mg) dose of BrE-3. 111In-labeled BrE-3 (5 mCi) was given simultaneously for scanning purposes. The only toxicity noted was hematological. Grade 4 platelet toxicity requiring transfusion support occurred in four patients. Grade 4 WBC toxicity was seen in two patients that resolved in 3-9 days. All hematological nadirs occurred approximately 25 days after treatment. Objective partial responses were noted in 4 of 8 (50%) patients with measurable tumors. Dose escalation is ongoing.

Adult↗
PubMed1995

Development and validation of column-switching high-performance liquid chromatographic methods for the determination of a potent AII receptor antagonist, TCV-116, and its metabolites in human serum and urine.

Column-switching HPLC methods have been developed and validated for the determination of a new antihypertensive prodrug, TCV-116 (I), and its metabolites, CV-11974 (II) and CV-15959 (III), in human serum and urine. Initial sample cleanup was achieved by extracting the analytes into an organic solvent. After chromatographing on an ODS column with a mobile phase consisting of acetonitrile and an acidic phosphate buffer, the zone of the analyte's retention was heart-cut onto a second ODS column with a mobile phase of acetonitrile and a phosphate buffer at a higher pH. Complete separation of the analytes and the endogenous peaks was accomplished by the two-dimensional chromatography. Good precision and linearity of the calibration standards, as well as the inter-day and intra-day precision and accuracy of quality control samples, were achieved. The limit of quantitation (LOQ), using 0.5 ml of serum, was 2 ng/ml for I, 0.8 ng/ml for II, and 0.5 ng/ml for III. The LOQ for urine sample was 10 ng/ml for II and III. Stability of the analytes during storage, extraction, and chromatography processes was established. The results illustrate the versatile application of column switching to method development of multiple analytes in various biological matrices. The methods have been successfully used for the analyses of I and its metabolites in thousands of clinical samples to provide pharmacokinetic data.

Angiotensin II↗
PubMed1995

A randomised controlled study of close monitoring of vulnerable psychiatric patients.

The care programme approach was introduced in mental health services in the UK in 1991. It was intended to improve the quality of care and prevent patients losing contact with care services and, by implication, to reduce psychiatric admissions. We did a study to find out if the approach worked. 400 patients from a London inner-city area who had been identified as psychiatrically vulnerable and included on a case register of patients with special needs were randomised into two groups of 200 each. One group received close supervision by nominated key-workers (as recommended in the care programme approach of the UK Department of Health), and the other received standard follow-up from psychiatric and social services. Outcome was recorded after eighteen months. Data on 393 patients was available for analysis. Of 197 patients allocated to standard care, 64 (32.5%) were lost to follow-up compared with 40 (20.4%) of 196 patients receiving close supervision (p = < 0.005). However, patients under close supervision had significantly more admissions (30% vs 18%, chi 2 = 7.61, p < 0.01) and spent 68% more days in hospital than the standard group. The findings of greater hospital-bed use, which differ from those of studies with community-based psychiatric teams, suggest that close supervision by a single key worker, as recommended in the care programme approach, will lead to greater success in maintaining contact with vulnerable patients, but is likely to lead to more psychiatric admissions.

Adult↗