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T J Stephenson

Publications and source records attributed to T J Stephenson.

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

Effect of nursing position on incidence, type, and duration of clinically significant apnoea in preterm infants.

AIM: To investigate whether nursing position has any effect on the frequency, type, and duration of apnoeas in preterm infants. METHOD: Thirty five preterm infants were entered into a crossover study and underwent polygraphic monitoring in each of two positions, prone and supine, the initial position being randomly allocated. Four parameters were recorded: nasal airflow, respiratory effort, electrocardiogram (ECG), and oxygen saturation. Each infant was studied in the two positions on the same day and each infant was studied only once. The studies were carried out on the neonatal intensive care unit. RESULTS: The infants were found to have significantly more central and mixed apnoeas in the supine than in the prone position. In addition, the severity of mixed apnoeas in terms of the duration of accompanying bradycardias and desaturations was greater in the supine than in the prone position (median difference 5.1 seconds in both instances). When considering the type of apnoea in relation to the duration, it was found that of those less than 20 seconds in duration there was a greater proportion that were central (25%) compared with the proportion of central (5%) apnoeas that were longer than 20 seconds. Of all the apnoeas that were less than 20 seconds in length, 16% were obstructive and 59% were mixed, whereas of the apnoeas greater than 20 seconds, 13% were obstructive and 82% were mixed. CONCLUSIONS: It appears that in addition to improving measures of lung function, the adoption of the prone nursing position for preterm infants may reduce associated problems of apnoea of prematurity.

Apnea↗
PubMed1994

Atrial natriuretic peptide in the preterm newborn.

Atrial natriuretic peptide (ANP), plasma renin and renin substrate concentrations (PRC and PRS) were measured in 31 preterm infants with idiopathic respiratory distress syndrome. Infants were studied at a mean of 1.4 days; 17 infants were also studied 2 days later. A 6-hour urine collection was made from 13 male infants on the first day of sampling to assess renal function. Both ANP and PRC were elevated and showed wide ranges of values (geometric means of 620 pg/ml and 18.4 ng/ml/h). Plasma ANP was significantly correlated with pH, PaCO2 and base excess. No correlations with parameters of cardiovascular or renal function were found. Plasma ANP rose in 13 of the 17 paired samples. We suggest that the very high ANP concentrations in these babies are a consequence of the pulmonary haemodynamic disturbances which accompany respiratory distress in the newborn.

Acid-Base Equilibrium↗
PubMed1994

Squamous cell carcinoma complicating lichen planus: a clinico-pathological study of three cases.

Squamous cell carcinoma complicating lichen planus is described in 3 patients. In 2, the cancers developed on the lower leg in chronic and hypertrophic lichen planus. In the other case, the cancer complicated lichen planus of the lip mucosa in a smoker. In the two cutaneous cases, the tumour and the adjacent skin showed features of lichen planus, including hypergranulosis, cytoid bodies and a lichenoid infiltrate. The association, though rare with cutaneous lichen planus when it tends to affect chronic hypertrophic lesions on the lower legs, is now well recognized with oral lichen planus. Patients with oral involvement warrant long-term follow-up, especially if they have other risk factors such as smoking or excessive ultraviolet exposure. Chronicity of lichen planus at other skin sites may also be a risk factor.

Aged↗
PubMed1994

Proliferating cell nuclear antigen immunostaining in keratoacanthoma and squamous cell carcinoma of the skin.

Proliferating cell nuclear antigen expression was used to seek differences between keratoacanthoma and squamous cell carcinoma of the skin. These lesions of the skin continue to provoke interest due to their different biological behaviour in spite of histologically similar appearances. The primary antibody, PC10 was used in a three stage avidin biotin peroxidase complex technique on section from 27 cases of KA, 15 of well, 16 of moderately- and 15 of poorly differentiated SCC. The distribution of positive cells was determined and then one thousand randomly chosen lesional epithelial nuclei were categorised for PCNA immunoreactivity and the results expressed as percentage of epithelial nuclei stained. Statistical analysis revealed a highly significant trend in increasing %PCNA with histological grade of skin lesion (P < 0.0001). Poorly differentiated, although not other grades of squamous cell carcinoma have a significantly higher proportion of PCNA labelled nuclei than keratoacanthoma. In addition, the distribution of PCNA positive nuclei in keratoacanthoma are usually peripheral contrasting with the more diffuse pattern seen in most cases of SCC. %PCNA alone was a more powerful predictor of histological subtype than distribution alone. PCNA immunohistochemistry not only provides additional information facilitating the differential diagnosis between keratoacanthoma and moderate or poorly differentiated squamous cell carcinoma but also underlines the perplexing similarity between keratoacanthoma and well differentiated squamous cell carcinoma.

Carcinoma, Squamous Cell↗
PubMed1994

Nodular basement membrane deposits in breast carcinoma and atypical ductal hyperplasia: mimics of collagenous spherulosis.

Collagenous spherulosis is characterised histologically by the accumulation of hyaline globules containing basement membrane components. Originally described in the breast, it has also been found in skin and salivary gland neoplasms. In the breast it has hitherto always been associated with benign disease and reports have asserted that this is invariably the case, cautioning against the diagnosis of malignancy when the condition is seen. We present here five cases with similar appearances to collagenous spherulosis in routine histology and immunohistochemistry, and ultrastructural studies in one of them, in which the condition was not associated with simple benign breast disease. Two of the cases were associated with invasive carcinomas of unusual histological types, one with intracystic papillary carcinoma, one with comedo ductal carcinoma-in-situ and one with atypical ductal hyperplasia. We suggest that appearances similar to collagenous spherulosis can be associated, either through being formed by a lesion or by collision, with malignancy and warn that on encountering the lesions the pathologist must not assume, as suggested in previous accounts, that it denotes a benign process. This is an important observation since collagenous spherulosis is likely to be encountered more frequently in the range of lesions biopsied in national breast screening programs.

Aged↗
PubMed1994

Nm23 protein expression in thyroid neoplasms.

The nm23 gene production has been heralded as a suppressor of metastasis in many human tumours but it is not clear at which stage in the metastatic process nm23 protein exerts its effect. The aim of this study was to test whether nm23 protein is associated with occurrence or category of angioinvasion. We have made use of the well documented fact that follicular carcinoma of the thyroid may show vascular invasion whereas papillary carcinomas may metastasis via the lymphatics. 65 thyroid tumours (20 follicular adenomas, 22 papillary carcinomas, 23 follicular carcinomas) were stained for nm23 protein using an immunopurified polyclonal antibody. Nm23 protein status showed no correlation with category of thyroid tumour. This is indirect evidence that nm23 does not suppress metastasis by influencing vascular invasion in this tumour type.

Adenocarcinoma, Follicular↗
PubMed1993

Nm23 protein expression in ductal in situ and invasive human breast carcinoma.

BACKGROUND: Mortality associated with human breast carcinoma is almost entirely due to subsequent metastatic disease, but the molecular basis of this metastasis is not understood. Elucidation of the genetic control of metastatic propensity of a tumor is important in determining prognosis and choice of therapy. Expression of nm23, a putative metastasis suppressor gene, has been detected in human breast cancers, but studies have not consistently shown high levels of the Nm23 messenger RNA or protein to be associated with better histological differentiation. This inconsistency suggests that Nm23 protein may act independently as a metastasis suppressor. PURPOSE: The purpose of this retrospective study was to investigate the relationship of Nm23 protein expression with 1) histology in ductal breast carcinoma in situ and 2) the variables considered to be the major prognostic indicators in invasive breast carcinoma. METHODS: We obtained formalin-fixed biopsy specimens of breast tissue excised from 128 patients with breast lesions detected by mammography. Of these patients, 35 had been diagnosed with benign breast disease, 26 with ductal carcinoma in situ (DCIS), and 67 with invasive carcinoma. Tissue sections were embedded in paraffin blocks, and immunohistochemical staining was used to determine Nm23 expression. Specimens were rated positive if all lesional epithelium was stained and negative if any lesional epithelium was unstained. Statistical analysis was performed by multiple regression analysis because of nonorthogonality of the data. RESULTS: All 35 examples of benign breast disease showed uniform epithelial cell staining. The seven cases of comedo DCIS were negative for Nm23 protein; all 18 noncomedo types were positive. Nm23 negativity was significantly associated with worsening invasive ductal carcinoma grade and advancing lymph node stage but not with tumor diameter or vascular invasion. Despite the putative antimetastatic role of the nm23 gene, no statistically significant association was found between Nm23 protein expression and vascular invasion. CONCLUSIONS: The precise role of the nm23 gene remains to be established, but our simplified immunohistochemical rating system shows an association between Nm23 protein expression and the two most significant prognostic factors relating to histologic grade and stage. Nm23 negativity distinguished comedo ductal carcinoma in situ from the other histological types, a finding consistent with the fact that comedo histology is known to have a higher likelihood of becoming invasive and of having higher cell proliferation rates and higher expression of growth factor (c-erb B2) receptor.

Breast Diseases↗
PubMed1993

'Anti-metastatic' nm23 gene product expression in keratoacanthoma and squamous cell carcinoma.

An inverse correlation has been demonstrated between nm23 gene expression and metastasis. The gene is located on chromosome 17q (q1.1-q2.1), a region distinct from tumour suppressor gene p53. We have previously reported expression of mutant products of p53 gene to be significantly associated with worsening degrees of differentiation in squamous cell carcinoma. nm23 gene product, which shows complete identity to human erythrocyte nucleoside diphosphate kinase, was used to raise an affinity-purified polyclonal antibody Ab-11 which is applicable to formalin-fixed and paraffin-embedded tissues. Keratoacanthomas and squamous cell carcinomas of the epidermis form a fascinating human tumour model in which to test the hypothesis that the nm23 gene confers 'anti-metastatic' properties, since the former never metastasise while the latter have this potential. Two observers rated immunohistochemistry for the nm23 gene product as the proportion of tumour positive from grades 1-4 (corresponding to 25, 50, 75 and 100% of tumour cells stained). Nineteen typical keratoacanthomas, 20 well, 21 moderately and 8 poorly differentiated epidermal squamous cell carcinomas were studied. The Jonckheere-Terpstra test statistic of association between staining grade and lesion type was 762.5, p = 0.189 (2 tails), p = 0.0945 (1 tail). There was no statistically significant trend in tumour staining from keratoacanthoma through decreasing grades of differentiation of squamous cell carcinoma. nm23 product expression does not appear to correlate with differentiation, itself an indicator of metastatic potential, in this system of human squamous cell neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Squamous Cell↗
PubMed1992

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Humans↗
PubMed1992

Mutant p53 oncogene expression in keratoacanthoma and squamous cell carcinoma.

The tumour suppressor gene p53, located on the short arm of chromosome 17, encodes for a nuclear protein which regulates cell proliferation by inhibiting cells entering S-phase. p53 mutations are alleged to be the commonest genetic abnormality in human cancer. We studied mutant p53 oncoprotein expression, using PAb1801 monoclonal antibody immunohistochemistry, in 25 'ideal' keratoacanthomas and 26 well-, 19 moderately and 18 poorly differentiated squamous cell carcinomas of the skin. While there was a highly significant trend in the proportion of p53 oncoprotein-positive lesions from keratoacanthomas to poorly differentiated squamous cell carcinomas (chi 2 = 17.13, df = 1, exact P = 0.00003), p53 expression was inadequate for distinguishing keratoacanthoma from well-differentiated squamous cell carcinoma (chi 2 = 2.55, df = 1, exact P = 0.18; corresponding to a sensitivity of 0.84 and a specificity of only 0.36).

Carcinoma, Squamous Cell↗
PubMed1992

Evaluation of techniques for delivery of steroids to lungs of neonates using a rabbit model.

Little is known about delivery of aerosolised steroids to neonatal patients undergoing assisted positive pressure ventilation and after extubation. A rabbit model has been established to investigate factors influencing drug delivery. Beclomethasone dipropionate, in a metered dose inhaler, was radiolabelled with technetium 99m. The mass median aerodynamic diameter of the aerosol was 3.3 (2.0) microns and the impactor measurements confirmed that the technetium distribution corresponded with that of the drug particles. The metered dose inhaler was actuated into a collapsible spacer that was used to ventilate and deliver aerosol to anaesthetised rabbits by a tracheostomy. From each actuation of the drug 2.9 (0.4)% of the aerosol deposited in the trachea and main bronchi and 1.2 (0.4)% in the lung. When the drug was delivered by a spacer device, with face-mask attachment, to rabbits breathing freely through a tracheostomy, aerosol deposition increased to 4.4 (2.1)% in the trachea and main bronchi and 1.9 (0.9)% in the lung lobes. The maximum change in systolic blood pressure after administration of aerosol by the collapsible spacer was a decrease of 13%. The methods described may prove useful for the delivery of inhaled steroids to neonatal patients likely to develop bronchopulmonary dysplasia.

Administration, Inhalation↗
PubMed1991

Factors influencing plasma renin and renin substrate in premature infants.

Concentrations of plasma renin (PRC) and plasma renin substrate (PRS) were measured during the first week of life in 52 infants born at less than 37 weeks' gestation (mean (SEM) gestation 30 (0.4) weeks, mean (SEM) birth weight 1.35 (0.08) kg). Both PRC (median 35, interquartiles 16.3, 94.5 ng/ml/hour) and PRS (median 2.3, interquartiles 1.3, 5.0 micrograms/ml) were raised compared with adults. The proportional rise in PRC was much greater than that in PRS, suggesting that PRS may be rate limiting in the generation of angiotensin I. Log10 PRC was inversely proportional to gestational age and a high urinary sodium loss was associated with a significantly raised log10 PRC. In hypoxaemic infants, there was a strong correlation between log10 PRS and haemoglobin concentration; this is a new observation in human infants but consistent with data available from other species.

Angiotensinogen↗
PubMed1991

A dose ranging study of ibuprofen suspension as an antipyretic.

A double blind trial was conducted to determine the dose of ibuprofen suspension, which is effective in reducing the body temperature. The principal measure of efficacy was a reduction in axillary temperature of 1 degree C or more three hours after dosing. A second objective of the trial was to compare the incidence and severity of side effects and the palatability of a range of ibuprofen doses. Ninety three children were included in the analysis. All four doses of ibuprofen studied (0.625 mg/kg-5 mg/kg) were associated with temperature reduction and only the lowest dose failed to satisfy the principal measure of efficacy. The influence of dose on the magnitude of the body temperature reduction was significant and the 5 mg/kg dose achieved the largest mean reduction in body temperature (2 degrees C). The tolerability and palatability of all doses studied were excellent. These findings suggest that ibuprofen is a good alternative to paracetamol as an antipyretic.

Child, Preschool↗
PubMed1991

Primary leiomyosarcoma of the liver.

A case of primary leiomyosarcoma of the liver is described and the problems in diagnosis and management are discussed together with a review of the available literature. These tumours have a favourable prognosis when diagnosed preoperatively and the value of electron microscopic findings in this situation are highlighted.

Angiography↗