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Biomedical subjects

B Smith

Publications and source records attributed to B Smith.

At least 217 records · Page 12Linked to original sources
PubMed1995

PGE1 suppresses the induction of collagen synthesis by transforming growth factor-beta 1 in human corpus cavernosum smooth muscle.

Collagen synthesis has been examined in primary cultures of human corpus cavernosum smooth muscle cells (HCCSMC), the major mesenchymal cell type of the corpus cavernosum. These cultures were grown from human surgical specimens and characterized by morphological and biochemical characteristics. These cells express mRNA for transforming growth factor-beta 1 (TGF-beta 1), a major regulator of extracellular matrix synthesis, as well as all three subtypes of TGF-beta receptors. Human corpus cavernosum smooth muscle cells primarily synthesize types I and III fibrillar collagen. Treatment of HCCSMC with exogenous TGF-beta 1 (80 pM.) induced a 2.5- to 4.5-fold increase in the synthesis of types I and III collagen and resulted in detectable levels of type V/XI collagen. Treatment of HCCSMC with the eicosanoid PGE1 in combination with TGF-beta 1 suppressed the induction of collagen synthesis by TGF-beta 1 in a dose-dependent manner with concomitant decreases in types I, III and V/XI collagen. The expression of TGF-beta 1 mRNA as well as types I and II TGF-beta receptors was induced by exogenous TGF-beta 1. Transforming growth factor-beta 1 mRNA induction was suppressed by PGE1. These data suggest that prostaglandins and TGF-beta 1 may play a key role in modulation of collagen synthesis in the corpus cavernosum, and in the regulation of fibrosis of the corpus cavernosum.

Alprostadil↗
PubMed1994

Neuroblastoma cell detection by reverse transcriptase-polymerase chain reaction (RT-PCR) for tyrosine hydroxylase mRNA.

The presence of tumour cells in peripheral blood of neuroblastoma patients is of considerable clinical importance. Nucleic acid amplification offers an opportunity to detect very small numbers of such cells, but in neuroblastoma a frequent specific abnormality in the tumour DNA suitable for this purpose has yet to be identified. To facilitate the detection of such cells we have developed RT-PCR using tyrosine hydroxylase (TH) as a tissue-specific target gene. TH mRNA was detected in 3 neuroblastoma cell lines and in all neuroblastoma tumours examined, but was undetectable in peripheral blood from children without neuroblastoma. The method was highly sensitive, detecting 1-10 neuroblastoma cells per 10(7) blood cells. Thirty blood samples from 24 patients were analysed and results were compared with known disease status. At diagnosis 4/7 patient blood specimens were positive; the four positive samples were from stage-4 patients. In blood samples from these patients 6-8 weeks after the initiation of treatment, TH mRNA was undetectable. Of 7 samples taken at the time of clinical relapse, 5 were positive; 4 of these were from patients with evidence of disseminating disease. Of 16 blood samples from disease-free patients, 14 were negative and 2 were positive. One positive patient in this group subsequently had a clinical relapse. These results show that this technique is of value for detecting neuroblastoma cells in peripheral blood. The significance of these cells at diagnosis, during treatment or on follow-up requires further evaluation.

Base Sequence↗
PubMed1994

Human progelatinase A can be activated by matrilysin.

The activation of human progelatinase A by other matrix metalloproteinases was studied by following both the loss of its N-terminal propeptide and the accompanying increase in the rate of hydrolysis of a synthetic substrate. Activated stromelysin 1 was unable to cause any activation of progelatinase A beyond that slowly occurring by autolysis, but an 8 h incubation with activated matrilysin was able to produce 64% of the activity generated by incubation with (4-aminophenylmercuric)acetate (APMA). Wild-type progelatinase A and a mutant proenzyme that cannot become active were both cleaved by matrilysin to a lower molecular weight species that had lost the propeptide. This shows that matrilysin activates progelatinase A by removing the propeptide in a process that does not require any autolytic cleavages.

Amino Acid Sequence↗
PubMed1994

Cyclotron future.

Explore the source record for details and available documents.

Cyclotrons↗
PubMed1994

The path to care in autism: is it better now?

Parents of children with autism often report problems associated with obtaining a diagnosis of their child's condition, family support, information, and appropriate services. To evaluate any changes in the situation over the last two decades, the families of all members of the West Midlands Autistic Society, age 19 years and below, were asked to fill in a questionnaire that covered aspects of detection, diagnosis, help and information received, and educational provision. Responses were obtained from 127 families, the children of whom formed an older group ages 10 years and above (n = 67) and a younger group ages 9 years and below (n = 61). Findings show that there have been improvements for the younger group in some areas, such as earlier referral, diagnosis, and statementing. However, the situation with respect to advice given by professionals and the support and provision available after referral is still much the same as that experienced by families of the older group of children. Many difficulties and hurdles remain which hinder parents and children on the path to care in autism.

Adolescent↗
PubMed1994

Measuring blood pressure in pregnant women: a comparison of direct and indirect methods.

OBJECTIVES: Our goals were to determine (1) whether Korotkoff phase IV or V sound was a more accurate measure of diastolic blood pressure in pregnancy and (2) interobserver variability of mercury sphygmomanometry of pregnant women. STUDY DESIGN: Direct (intraarterial) and indirect (mercury sphygmomanometry) blood pressures were compared in 28 pregnant women. Interobserver variability was assessed in a separate study of 86 pregnant women using four highly trained observers. RESULTS: (1) Routine sphygmomanometry underestimated direct systolic pressure by 11 (3, 18) mm Hg, p < 0.001 (median, interquartile range of differences). Phase IV Korotkoff sound overestimated direct diastolic pressure by 9 (2, 12) mm Hg (p < 0.001) and phase V by 4 (2, 7) mm Hg (p = 0.04). Phase V-recorded diastolic pressure was closer to direct diastolic pressure significantly more often (75%) than was phase IV-recorded diastolic pressure (21%) (p = 0.003). Mean arterial pressures did not differ significantly according to the method used. (2) Median blood pressures did not differ among the four observers for systolic, diastolic phase IV, or phase V recordings. Maximum difference for blood pressure recording among observers was 4 (2, 6) mm Hg. CONCLUSIONS: Auscultatory sphygmomanometry in pregnant women underestimates systolic and overestimates diastolic blood pressure, but the phase V Korotkoff sound is more likely to represent the true diastolic pressure than is the phase IV sound.

Auscultation↗
PubMed1994

Measurement of the attenuation coefficient for Livermore Thoracic Phantom lungs fabricated using contemporary materials.

The University of Cincinnati has reproduced the original formulation for the Livermore Thoracic Phantom lungs using contemporary materials and has adopted the linear attenuation coefficient as the primary quality assurance parameter for evaluating the performance capabilities of these new lung phantoms. The Livermore Thoracic Phantom was originally fabricated in 1978 to intercalibrate detector systems used to measure plutonium and other low-energy, photon emitting radionuclides deposited in the respiratory tract. The linear attenuation coefficient is a critical performance indicator for these phantom lungs since the presence of any material with a high effective atomic number (where Z > or = 20) will make a significant change in the photoelectric cross section, the predominant mode of interaction for plutonium x rays. A set of test lungs was fabricated with KCl to introduce a known quantity of 40K in the phantom and to determine, by measurement and calculations, what change would be made to the attenuation coefficient at photon energies below 100 keV as a result of the modified formulation. The KCl increased the linear attenuation coefficient below 60 keV by more than a factor of two, which would produce a substantial systematic error in any subsequent calibration measurements performed with these modified phantom lungs. These results support use of the attenuation coefficient as an important performance indicator for the Livermore Thoracic Phantom lungs and also suggest that KCl not be added to the lung tissue substitute formulation as a means to incorporate 40K in the phantom for low energy calibrations.

Humans↗
PubMed1994

Predictive testing for Huntington disease: social characteristics and knowledge of applicants, attitudes to the test procedure and decisions made after testing.

An investigation has been made of the social characteristics and knowledge and experience of Huntington disease (HD) for the first 80 individuals considering presymptomatic testing (applicants) at the medical genetics centres in Edinburgh and Glasgow and of attitudes to the test procedure and decisions made after testing for those who received a result. Sixty-one percent of applicants were female and 31% were over 40 years old. Almost all had a symptomatic parent but 38% did not know HD was in their family until they were over 25 years old and 48% had never received genetic counselling. Thirty-eight percent of applicants first heard of the test at the genetic clinic, 20% from a relative and 20% from the media, but none had received information from their GP. Thirty-one applicants did not have the test because they voluntarily withdrew (17 individuals), their family structure was unsuitable or no informative result was possible (11 individuals), or they were diagnosed clinically as being affected (3 individuals). Those who voluntarily withdrew did not differ significantly from the 49 who received a result in social characteristics or knowledge and experience of HD. Twenty-two individuals were found to be at increased risk (IR) (> 50% of becoming affected) and 27 to be at decreased risk (DR) (< 50% of becoming affected). There was a median period of 9 months between entering the test procedure and receiving a result and the main criticism of the procedure was that it took too long to complete and several individuals experienced considerable anxiety while awaiting their result.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Evaluation of a microdot immunofluorescent antigen detection test for Chlamydia trachomatis.

OBJECTIVE: To evaluate a centrifuge enhanced direct immunofluorescent antigen test (MD test), compared with conventional culture and ELISA testing in the diagnosis of Chlamydia trachomatis infection. SETTING: A District General Hospital situated 30 miles from a University Department of Medical Microbiology. SUBJECT AND METHOD: A prospective study on specimens from 638 patients. Culture was performed on 348 specimens from genitourinary medicine patients and ELISA testing was carried out on 272 specimens from Gynaecology patients. RESULTS: When compared with culture the MD test had a sensitivity of 90.6%, specificity of 96.8%, positive predictive value of 74.3% and a negative predictive value of 99%. When compared with confirmed ELISA results the MD test had a sensitivity of 100%, specificity of 98.8%, positive predictive value of 78.5% and negative predictive value of 100%. CONCLUSION: The MD test compares favourably with other chlamydial diagnostic techniques and in our setting is preferable to sending specimens for chlamydial culture. It is not suitable as the sole diagnostic method for screening large numbers of specimens but is a cost effective confirmatory test for positive ELISA results.

Antigens, Bacterial↗
PubMed1994

Development of a user-defined surgical database using a personal computer network.

Advances in personal computer technology have made powerful methods for the collection and analysis of patient information available to clinical users. This report details the development of a multi-user database distributed across a network of personal computers that facilitates operative scheduling, and collection and analysis of operative data. Clinicians from each surgical service in our medical center developed customized data entry programs that contribute information centrally through a telephone-line network to prepare the daily operative schedule. Subsequently, information from the operating rooms is added to the preoperative database to form an operative log, which is distributed to client services for further analysis and modification. This system has improved the efficiency and accuracy of operative scheduling and information management and shifted the burden of data collection away from the physician. Widespread availability of these data has contributed to the development of an effective quality improvement program and facilitated effective management of personnel and resources.

Computer Communication Networks↗
PubMed1994

Double gloving might predispose to injury by blunting temperature perception.

Double gloving may blunt perception of excessively warm instruments. We describe a case where this might have contributed to a cutaneous burn in a patient undergoing laparoscopic cholecystectomy. To test the role of two gloves in blunting temperature perception, we performed two experiments. In the first, 250 ml of water at 70 degrees C were placed in one glove or two gloves, and the rate of change of temperature after submersion in a bath at 18 degrees C was measured. The use of two gloves was associated with a marked decrease in rate of change in temperature (temperature at 5 min 37 +/- 2.3 degrees C [double gloves] versus 24 +/- 2.6 degrees C [single glove]; p < 0.001). In the second experiment, a thermometer covered with no gloves, one glove, or two gloves (group 5; n = 5) was submerged in a water bath at 90 degrees C. After 5 s, the temperature without gloves was 85.2 +/- 2.2 degrees C compared with 61.3 +/- 0.8 degrees C with one glove and 45.6 +/- 1.1 degree C with two gloves (p < 0.001). After 15 s, the temperature without gloves was 90.2 +/- 1.6 degrees C compared with 76.5 +/- 0.5 degrees C with one glove, and 64.4 +/- 0.8 degrees C with two gloves (p < 0.001). We conclude that the use of two gloves significantly decreases heat transmission, thus altering temperature perception.

Aged↗
PubMed1994

Breast reconstruction with myocutaneous flaps in previously irradiated patients.

Breast reconstructions performed with latissimus dorsi and transverse rectus abdominis myocutaneous (TRAM) flaps in 82 patients with a history of previous chest-wall irradiation were compared with similar reconstructions in 202 nonirradiated patients to determine whether prior irradiation was associated with more frequent complications and to determine the success rate of breast reconstruction using distant flaps in irradiated patients. The mean dose of radiation administered was 5637 cGy. Complications in the reconstructed breast were more frequent in the irradiated patients (39 percent) than in the nonirradiated patients (25 percent; p = 0.03). In the irradiated group, breast complications were more common in reconstructions performed with the latissimus dorsi flap (63 percent) than in those performed with the TRAM flap (33 percent; p = 0.063). Aesthetic outcomes also were slightly poorer in the irradiated patients. Although complications were more common and aesthetic outcomes not as good in previously irradiated patients, we do not consider such irradiation to be a contraindication to breast reconstruction.

Abdominal Muscles↗