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Biomedical subjects

T Wheeler

Publications and source records attributed to T Wheeler.

At least 73 records · Page 4Linked to original sources
PubMed1994

Short report: identification of a specific pattern of vascular endothelial growth factor mRNA expression in human placenta and cultured placental fibroblasts.

Reverse transcription and the polymerase chain reaction (PCR) were used to detect vascular endothelial growth factor (VEGF) mRNA in human placental tissue and cultured placental fibroblasts obtained during the first trimester of pregnancy. The primers for VEGF corresponded to areas in exon 4 and exon 8 of the VEGF gene. After one round of PCR three products, equivalent to VEGF121, VEGF165 and VEGF189, were detected within placental tissue and cultured placental fibroblasts. A further round of PCR revealed the presence of two more products equivalent to VEGF206 and VEGF145. Thus, in addition to the production of readily secreted forms of VEGF (VEGF121 and VEGF165), the placenta produces several transcripts expected to increase the growth factor pool of the extracellular matrix.

Base Sequence↗
PubMed1994

Five year follow-up after radical prostatectomy for localized prostate cancer--a study of the impact of different tumor variables on progression.

Fifty-one patients with clinically localized prostate cancer stages A and B, who underwent radical prostatectomy have been followed for a minimum of 5 years. The impact of age, stage, capsular penetration, total tumor volume, Gleason score, seminal vesicle invasion and lymph node metastases on progression has been evaluated. Progression free survival was calculated according to the Kaplan-Meier method. Uni- and multivariate analyses were performed according to the Cox proportional hazards model. During the observation period 16 patients (31%) experienced progression. Tumor volume, grade and seminal vesicle invasion emerged as statistically significant predictors of tumor progression in the survival analyses while age at surgery, preoperative stage and different levels of capsular penetration were not statistically significant. The findings in the Cox models were in accordance with those at actuarial survival analyses though tumor volume was the only variable proven to have an independent statistically significant influence on progression.

Aged↗
PubMed1993

Assays of retinoid dehydrogenases by phase partition.

Two modifications of an extraction assay for retinoid dehydrogenases are described. The first method involves the transfer of tritium from carbon-15 of [15-3H]-retinol or [15-3H]retinaldehyde to NAD, whereas in the second method, tritium from [3H]NADPH is transferred to all-trans-retinaldehyde. Since both versions of the assay involve the interconversion of water-soluble and -insoluble tritium-labeled compounds, a simple phase partition is sufficient to separate labeled products from labeled reactants. The assays are shown to provide reliable estimations of the reaction progress for three retinoid dehydrogenases of the visual system when compared to HPLC analysis of retinoid products or gel filtration analysis of pyridine nucleotide. The assays will be useful in studying retinoid dehydrogenases from other tissues and in principle can be modified for other dehydrogenase reactions with water-insoluble substrates.

Alcohol Oxidoreductases↗
PubMed1993

Large fetal heart rate decelerations at term associated with changes in fetal heart rate variation.

OBJECTIVE: The objective was to determine whether large antepartum decelerations in fetal heart rate were associated with a switch from high to low fetal heart rate variation, suggestive of a change in sleep state, and whether the variation predicted outcome. STUDY DESIGN: Retrospective computerized analysis of 10,272 cardiotocographic records from 3998 patients at 37 to 42 weeks' gestation from four centers in England and Italy identified 140 good-quality records with large decelerations (more than 20 lost beats in area). RESULTS: In otherwise normal cardiotocograms a large deceleration had a 40% chance of association with a downward change in fetal heart rate variation (69% when the deceleration exceeded 100 lost beats). The change resembled that occurring naturally with behavioral states. Uterine contractions did not always precede large decelerations. When they did, the lag time (peak of contraction-trough of deceleration) increased from 28 seconds (at 20 to 29 lost beats) to > 100 seconds with increase in deceleration area. Of patients with large decelerations 76% had a normal vaginal delivery. CONCLUSION: Large decelerations near term, present in up to 5% of patients with otherwise normal fetal heart rate and variation, are often associated with a fall in fetal heart rate variation characteristic of a change in sleep state, without ominous significance.

Female↗
PubMed1993

Screening for fetal distress in labour using the umbilical artery blood velocity waveform.

OBJECTIVE: To investigate the potential value of umbilical artery blood velocity wave-form measurement as a screening test for intrapartum fetal distress on admission to the labour ward. DESIGN: Prospective study drawn from the local population of pregnant women. SETTING: The labour ward of the Princess Anne Hospital, Southampton, UK. SUBJECTS: 334 women with singleton pregnancies of at least 37 weeks gestation. MAIN OUTCOME MEASURE: Emergency caesarean section for fetal distress. RESULTS: There was a twelve-fold increase in the rate of emergency caesarean section for fetal distress (95% Confidence Interval (CI), 4.9-29) among women with a systolic/diastolic (S/D) ratio > or = 3.0, when compared to those with an S/D ratio of < 3.0 (P < 0.00001). Measurement of the umbilical artery blood velocity waveform compared favourably with admission cardiotocography. CONCLUSIONS: Umbilical artery blood velocity waveform analysis may be used to screen for fetal distress in labour and appears to be particularly sensitive to problems of placental origin. However, it is not likely to confer benefit in labour wards whose fetal heart rate monitoring policy is determined by pregnancy risk factors and admission cardiotocography.

Blood Flow Velocity↗
PubMed1992

Frequency and location of extracapsular extension and positive surgical margins in radical prostatectomy specimens.

Positive surgical margins have been reported with disturbing frequency in radical prostatectomy specimens and may portend an increased risk of eventual treatment failure. We determined the location of any cancer, extracapsular extension and positive surgical margins in 144 consecutive step-sectioned radical prostatectomy specimens. Of the 46 stage A cancer patients 98% had residual cancer in the prostate after transurethral resection and in 76% cancer was found posteriorly in the gland. Extracapsular extension was identified in 10 patients (22%): anteriorly in 5, posterolaterally in 5 and on the most apical transverse section in 4. Positive margins were found in 10 patients (22%) and half of these occurred posterolaterally. Of the 98 stage B cancer patients tumor was located posteriorly in 97%. Extracapsular extension was found in 62 patients (63%) and in 87% of these it was located posterolaterally. Positive margins were found in 23%, most commonly in the posterolateral and rectal areas (57% and 26%, respectively), and in more than half of these the positive margin resulted from incision into the capsule. In 18 of the 144 patients (13%) a single positive surgical margin was the only pathological indicator of treatment failure and half of these occurred in the area of the neurovascular bundle. Some of these patients with extraprostatic tumor might have been cured if wide excision of the neurovascular bundle had been performed. Overemphasis on preservation of potency during radical prostatectomy may leave some patients with persistent local disease.

Humans↗
PubMed1992

A CD4-derived peptide carrier blocks acute HIV-1 infection in vitro and binds to gp120 in the presence of Walter-Reed stage 1-6 HIV+ sera.

A peptide containing amino acid residues 41-84 of the CD4 molecule was synthesized and coupled through a thioether bond to human serum albumin. This conjugate bound to gp120 with an affinity that was half that of CD4 and blocked the HIV infection in vitro with an efficacy tenfold lower than that of CD4. More importantly, the CD4 peptide-human serum albumin conjugate could bind to gp120 in the presence of HIV+ sera from 18 Walter Reed stage 1-6 patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Antenatal cardiotocogram quality and interpretation using computers.

OBJECTIVE: To test the application in practice of computerized fetal heart rate (FHR) analysis in pregnancy. DESIGN: Randomized distribution of subjects with computerized analysis automatically revealed or concealed. SETTING: A district general hospital and a teaching hospital outside London. SUBJECTS: 2869 pregnant women studied within a year. OUTCOME MEASURES: Quality and duration of the cardiotocogram; quantitative measurement of FHR variation; number of stillbirths. RESULTS: With interactive advice to the operator, records were of improved quality (up to 28% without signal loss) with potentially much reduced recording time. The short-term FHR variation measured in the last records before intervention is reported for the first time. CONCLUSION: The benefits of using the computers include improvement in record quality and saving of time. In addition, where interpretation depended on estimation of FHR variation there was prima facie evidence of observer misinterpretation; visual analysis was unreliable. A larger trial is now required with more rigorous constraints on intervention.

Cardiotocography↗
PubMed1991

Comparison of the T/QRS ratio of the fetal electrocardiogram and the fetal heart rate during labour and the relation of these variables to condition at delivery.

The T/QRS ratio of the fetal electrocardiogram (ECG) was recorded to within 30 min of delivery from 105 women in labour. There were no significant differences in the mean T/QRS ratio in the last hour of record between those with normal and intermediate, or abnormal fetal heart rate (FHR) patterns. In 66 labours the mean T/QRS ratio in the first hour of record was compared with that of the last hour; the only significant change was a small decrease in the mean ratio from 11% to 7% in a group of 11 fetuses with an abnormal FHR pattern throughout the recording time. Eight babies were born with evidence of acidosis (umbilical artery pH less than or equal to 7.16), and another four were born in poor condition (1 min Apgar score less than 4) without evidence of acidosis; none had a mean last hour T/QRS ratio significantly different from the previously established normal range.

Apgar Score↗
PubMed1991

Fetal heart rate and intrauterine growth.

OBJECTIVE: To assess whether fetal heart rate in early and late pregnancy relates to size at birth. DESIGN: Prospective study of fetal heart rates in early and late pregnancy. SETTING: Princess Anne Hospital, Southampton. SUBJECTS: 63 primigravid women. MAIN OUTCOME MEASURES: Anthropometric measurements made on the newborn infant. RESULTS: There were no differences in heart rate between the sexes at 18 weeks gestation but by 36 weeks the boys had rates which were 4.4 beats lower than those of the girls. Higher fetal heart rate at 18 weeks was associated with lower ponderal index, smaller head circumference and smaller mid-arm circumference. There were no trends in fetal heart rate at 36 weeks with any birth measurements. CONCLUSION: Babies born at term who have a pattern of neonatal measurements which reflect growth retardation have raised heart rates in early pregnancy. Influences which impair fetal growth appear to take effect early in gestation.

Anthropometry↗
PubMed1989

Multiple endocrine neoplasia type 2a associated with cutaneous lichen amyloidosis.

PURPOSE: To describe and characterize the association of hereditary cutaneous lichen amyloidosis with multiple endocrine neoplasia type 2a (MEN 2a). DESIGN: Survey of a family for two diseases. SETTING: Evaluation of patients at a clinical research center. PATIENTS: Nineteen family members with MEN 2a. MEASUREMENTS AND MAIN RESULTS: In this family cutaneous lichen amyloidosis presented as multiple infiltrated papules overlying a well-demarcated plaque in the scapular area of the back (right or left). Immunohistochemical studies showed amyloid that stained for keratin but not calcitonin. Three family members had the characteristic skin lesion and also carried the gene for MEN 2a; two additional members carried the gene for MEN 2a, but did not manifest the observable skin changes associated with lichen amyloidosis. CONCLUSIONS: From the findings in this kindred and in another recently reported but unrelated family with an identical type of pruritic skin rash and MEN 2a, several conclusions can be drawn. First, the syndrome of cutaneous amyloidosis and MEN 2a is a clearly defined autosomal dominant hereditary syndrome. Second, the dermal amyloid appears to be caused by deposition of keratin-like peptides rather than by calcitonin-like peptides. Third, known families with hereditary lichen amyloidosis should be screened to determine the true frequency of this syndrome.

Adrenal Gland Neoplasms↗
PubMed1989

Variation in the T/QRS ratio of fetal electrocardiograms recorded during labour in normal subjects.

The T/QRS ratio of the fetal ECG was obtained during labour from 25 women with normal pregnancies. The poor signal-to-noise ratio of the unprocessed signals, chiefly due to baseline wander, led to a wide variation between individual measurements. This problem was overcome by data averaging, the ratio being expressed as a mean over 1-min epochs. The average T/QRS ratio of each labour record ranged from 4% to 23% with a mean of 10% (for all 25). The average range (between 5th and 95th centile) of the 1-min T/QRS ratios was 13% and there were no significant changes as labour progressed. The effect of contractions on the T/QRS ratio was measured from eight subjects and found to be inconsistent.

Adolescent↗
PubMed1989

Familial cutaneous lichen amyloidosis in association with multiple endocrine neoplasia type 2A: a new variant.

Multiple endocrine neoplasia type 2A (MEN 2A) is a rare hereditary disease transmitted in families as an autosomal dominant trait. We have identified a family in which the expression of a rare autosomal dominant form of cutaneous lichen amyloidosis appears to cosegregate with MEN 2A. In this family the skin lesion presented as multiple infiltrated papules overlying well demarcated plaques over the scapular area (right or left). Immunohistochemical studies demonstrated amyloid which stained for keratin but not calcitonin. A total of 19 members were screened. Three members of the family have the characteristic skin lesion and MEN 2A; two additional members have MEN 2A but have not manifested observable skin changes of lichen amyloidosis. Another unrelated Italian family with a similar type of pruritic skin rash and MEN 2A has been reported recently. Although the initial skin biopsies were negative for amyloidosis, subsequent biopsy established the association of MEN 2A with amyloidosis in this family also. When these kindreds are combined, several conclusions can be drawn. First, the syndrome of cutaneous amyloidosis and MEN 2A appears to be a clearly defined autosomal dominant hereditary syndrome. Whether this syndrome can be linked to chromosome 10 is not yet known. Second, the dermal amyloid appears to be caused by deposition of keratin-like peptides rather than calcitonin-like peptides. Third, we believe that patients with the hereditary form of cutaneous amyloid should be screened for medullary thyroid carcinoma to determine the true frequency of this syndrome.

Amyloidosis↗