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Biomedical subjects

A Lucas

Publications and source records attributed to A Lucas.

At least 127 records · Page 7Linked to original sources
PubMed1998

Fatal shoulder dystocia: a review of 56 cases reported to the Confidential Enquiry into Stillbirths and Deaths in Infancy.

OBJECTIVE: To use information collected by the Confidential Enquiry into Stillbirths and Deaths in Infancy to help obstetric, midwifery and paediatric practice in the management of shoulder dystocia. DESIGN: Review of casenotes by a multidisciplinary focus group. SAMPLE: All 56 cases reported to the Confidential Enquiry into Stillbirths and Deaths in Infancy from England, Wales and Northern Ireland in 1994 and 1995, where stillbirth or neonatal death was attributed to shoulder dystocia. MAIN OUTCOME MEASURES: Case notes were reviewed with respect to a range of perinatal variables. Comparisons were made with normative data from other studies when appropriate. RESULTS: Maternal obesity and big babies were over-represented in pregnancies complicated by fatal shoulder dystocia. Fetal compromise was recorded in 26% of labours. The median time interval between delivery of the head and the rest of the body was only five minutes. The lead professional at the time the head was delivered was a midwife in 65% of cases. Middle grade or senior obstetric staff were supervising 47% of cases by the time the body was delivered. CONCLUSIONS: Antenatal prediction of shoulder dystocia is imprecise, and the majority of deliveries are attended by midwives. A relatively brief delay in delivery of the shoulders may be associated with a fatal outcome.

Autopsy↗
PubMed1998

Abnormal expression of epiligrin and alpha 6 beta 4 integrin in basal cell carcinoma.

BACKGROUND: Basal cell carcinoma is characterized by local invasion, and only rarely metastasizes. The role of the containing basement membrane (BM) in this tumor is unclear. Several BM components have been shown to be absent or significantly reduced in BM surrounding infiltrating tumor. OBJECTIVE: The purpose of this study is to examine the expression of epiligrin, a BM-associated glycoprotein, and the integrin chains alpha 3, alpha 6, beta 1, and beta 4 in the basement membranes surrounding basal cell carcinoma. METHODS: Samples were obtained from 20 patients with basal cell carcinomas and subjected to a standard avidin biotin complex/alkaline phosphatase immunohistochemical technique using a panel of antibodies. RESULTS: There was a consistent abnormality of expression of epiligrin, alpha 6, and beta 4. CONCLUSION: We propose that reduced expression of epiligrin is involved in the pathogenesis of the local invasion by tumor and that an altered integrin ratio in basal cell carcinoma enhances tumor spread.

Antigens, Neoplasm↗
PubMed1998

Endocytosis of pro-cathepsin D into breast cancer cells is mostly independent of mannose-6-phosphate receptors.

Cathepsin D trafficking is altered in cancer cells, leading to increased secretion of the pro-enzyme, which can be reinternalized by the same cancer cells and by stromal cells. We studied pro-cathepsin D endocytosis in two human breast cancer cell lines (MDA-MB231, MCF-7) and in human normal fibroblasts. Pro-enzyme uptake was studied indirectly through immunofluorescence analysis of anti-pro-cathepsin D monoclonal antibodies internalized in living cells. Both cancer cell lines internalized the pro-cathepsin D-antibody complex into endosomal compartments in the presence of 10 mM mannose-6-phosphate. Non-malignant fibroblasts, which do not secrete pro-cathepsin D, only internalized anti-cathepsin D antibody when purified pro-cathepsin D was added and this endocytosis was totally inhibited by mannose-6-phosphate. Cathepsin D endocytosis in cancer cells was not mediated by lectins or another receptor binding the cathepsin profragment. It was not due to fluid endocytosis, since another protein pS2 secreted by MCF-7 was not endocytosed with its antibody in the same conditions. Double-immunofluorescence and confocal microscopy analyses revealed that antibodies specific to pro-cathepsin D (M2E8) and to the mannose-6-phosphate/IGFII receptor were co-internalized independently in non-permeabilized MDA-MB231 cells and MCF-7 cells, but not in fibroblasts. Moreover, when metabolically labelled pro-cathepsin D secreted by MCF-7 or MDA-MB231 cells was incubated with homologous or heterologous non-radioactive cells, the time-dependent uptake and maturation of the pro-enzyme into fibroblasts were totally inhibited by mannose-6-phosphate, whereas they were not in the two breast cancer cell lines. The percentage of mannose-6-phosphate-independent binding of radioactively labelled pro-cathepsin D to MDA-MB231 cells at 16 degrees C was higher (7-8%) at low pro-cathepsin D concentration than at high concentration (1.5%), indicating the presence of saturable binding site(s) at the cell surface that are different from the mannose-6-phosphate receptors. We conclude that, in contrast to fibroblasts, breast cancer cells can endocytose the secreted pro-cathepsin D by a cell surface receptor that is different from the mannose-6-phosphate receptors or other lectins. The nature of this alternative receptor and its significance in the action of secreted pro-cathepsin D remain to be elucidated.

Antibodies↗
PubMed1998

Lower limb angiography: a prospective study comparing carbon dioxide with iodinated contrast material in 30 patients.

OBJECTIVE: We prospectively compared patients' tolerance for and the usefulness of carbon dioxide (CO2) with iodinated contrast material in the study of lower limb arteries in 30 patients. SUBJECTS AND METHODS: We systematically performed digital subtraction angiography with electronic injection of CO2 (injection average, 330 ml) and digital subtraction angiography with iodinated contrast material in 30 patients (20 men and 10 women; mean age, 67.5 years) suffering from lower limb ischemia. Patients were monitored for vital signs and comfort. Four reviewers subjectively evaluated vessel visibility at five levels (pelvis, thigh, knee, calf, and ankle). We used the Student's t test to evaluate the tolerance and the global examination quality. The chi-square test was used to evaluate the stratified analysis of the observers and scores of the image quality according to the anatomic level studied. Bartlett's test of equality of variances was used to compare the variances between the readers. RESULTS: CO2 was less well tolerated (p < .01) than iodine was. Fifty-three percent of patients reported CO2 was equally well tolerated (53%), 40% reported more discomfort than with iodine, and 4% reported less discomfort than with iodine. Both techniques were equivalent for imaging of the iliac arteries, but CO2 performed poorly in the arteries below the knee (p << .001). CONCLUSION: CO2 angiography with electronic injection proved to be less comfortable than iodinated angiography. CO2 arteriography is equivalent to iodinated arteriography for imaging the iliac arteries but imaging performance progressively degrades in the more distal arteries of the legs.

Adult↗
PubMed1998

Computed tomography guided thoracic sympatholysis for palmar hyperhidrosis.

METHODS: Sixteen patients (mean age 26.3 years; range 18-38) with palmar hyperhidrosis underwent 29 sympatholyses after unsuccessful medical, and in 8 ionophoresis, treatments. Sympatholysis was performed under local anesthesia with computed tomographic guidance. After opacification of the injection site at T3 with Iopamiron 200, phenolization was performed with 10 ml 6% phenol. RESULTS: Good immediate results evaluated on the basis of venous dilatation, and dryness and warmth of the skin were obtained in 23 cases (80%). There were 6 immediately unsuccessful procedures in 4 patients. At 20 months, good results, assessed on the basis of objective criteria and subjective patient self-evaluation were obtained in 22 cases (75% including immediate failures). Computed tomography guided thoracic sympatholysis performed under local anesthesia is an effective treatment for palmar hyperhidrosis. Morbidity is low and hospital stay is short. CONCLUSIONS: Our findings suggest that thoracic sympatholysis should be indicated as the first intention procedure when surgery is required in patients with palmar hyperhidrosis.

Adolescent↗
PubMed1997

Flow-mediated dilation in 9- to 11-year-old children: the influence of intrauterine and childhood factors.

BACKGROUND: Early life factors, particularly size at birth, may influence later risk of cardiovascular disease, but a mechanism for this influence has not been established. We have examined the relation between birth weight and endothelial function (a key event in atherosclerosis) in a population-based study of children, taking into account classic cardiovascular risk factors in childhood. METHODS AND RESULTS: We studied 333 British children aged 9 to 11 years in whom information on birth weight, maternal factors, and risk factors (including blood pressure, lipid fractions, preload and postload glucose levels, smoking exposure, and socioeconomic status) was available. A noninvasive ultrasound technique was used to assess the ability of the brachial artery to dilate in response to increased blood flow (induced by forearm cuff occlusion and release), an endothelium-dependent response. Birth weight showed a significant, graded, positive association with flow-mediated dilation (0.027 mm/kg; 95% CI, 0.003 to 0.051 mm/kg; P=.02). Childhood cardiovascular risk factors (blood pressure, total and LDL cholesterol, and salivary cotinine level) showed no relation with flow-mediated dilation, but HDL cholesterol level was inversely related (-0.067 mm/mmol; 95% CI, -0.021 to -0.113 mm/mmol; P=.005). The relation between birth weight and flow-mediated dilation was not affected by adjustment for childhood body build, parity, cardiovascular risk factors, social class, or ethnicity. CONCLUSIONS: Low birth weight is associated with impaired endothelial function in childhood, a key early event in atherogenesis. Growth in utero may be associated with long-term changes in vascular function that are manifest by the first decade of life and that may influence the long-term risk of cardiovascular disease.

Birth Weight↗
PubMed1997

Aluminum neurotoxicity in preterm infants receiving intravenous-feeding solutions.

BACKGROUND: Aluminum, a contaminant of commercial intravenous-feeding solutions, is potentially neurotoxic. We investigated the effect of perinatal exposure to intravenous aluminum on the neurologic development of infants born prematurely. METHODS: We randomly assigned 227 premature infants with gestational ages of less than 34 weeks and birth weights of less than 1850 g who required intravenous feeding before they could begin enteral feeding to receive either standard or specially constituted, aluminum-depleted intravenous-feeding solutions. The neurologic development of the 182 surviving infants who could be tested was assessed by using the Bayley Scales of Infant Development at 18 months of age. RESULTS: The 90 infants who received the standard feeding solutions had a mean (+/-SD) Bayley Mental Development Index of 95+/-22, as compared with 98+/-20 for the 92 infants who received the aluminum-depleted solutions (P=0.39). In a planned subgroup analysis of infants in whom the duration of intravenous feeding exceeded the median and who did not have neuromotor impairment, the mean values for the Bayley Mental Development Index for the 39 infants who received the standard solutions and the 41 infants who received the aluminum-depleted solutions were 92+/-20 and 102+/-17, respectively (P=0.02). The former were significantly more likely (39 percent, vs. 17 percent of the latter group; P=0.03) to have a Mental Development Index of less than 85, increasing their risk of subsequent educational problems. For all 157 infants without neuromotor impairment, increasing aluminum exposure was associated with a reduction in the Mental Development Index (P=0.03), with an adjusted loss of one point per day of intravenous feeding for infants receiving the standard solutions. CONCLUSIONS: In preterm infants, prolonged intravenous feeding with solutions containing aluminum is associated with impaired neurologic development.

Aluminum↗
PubMed1997

The T1/35kDa family of poxvirus-secreted proteins bind chemokines and modulate leukocyte influx into virus-infected tissues.

Immunomodulatory proteins encoded by the larger DNA viruses interact with a wide spectrum of immune effector molecules that regulate the antiviral response in the infected host. Here we show that certain poxviruses, including myxoma virus. Shope fibroma virus, rabbitpox virus, vaccinia virus (strain Lister), cowpox virus, and raccoonpox virus, express a new family of secreted proteins which interact with members of both the CC and CXC superfamilies of chemokines. However, swinepox virus and vaccinia virus (strain WR) do not express this activity Using a recombinant poxviruses, the myxoma M-T1 and rabbitpox virus 35kDa secreted proteins were identified as prototypic members of this family of chemokine binding proteins. Members of this T1/35kDa family of poxvirus-secreted proteins share multiple stretches of identical sequence motifs, including eight conserved cysteine residues, but are otherwise unrelated to any cellular genes in the database. The affinity of the CC chemokine RANTES interaction with M-T1 was assessed by Scatchard analysis and yielded a Kd of approximately 73 nM. In rabbits infected with a mutant rabbitpox virus, in which the 35kDa gene is deleted, there was an increased number of extravasating leukocytes in the deep dermis during the early phases of infection. These observations suggest that members of the T1/35kDa class of secreted viral proteins bind multiple members of the chemokine superfamily in vitro and modulate the influx of inflammatory cells into virus-infected tissues in vivo.

Amino Acid Sequence↗
PubMed1997

Infant feeding and maternal concerns about stool hardness.

From a questionnaire completed by 195 mothers of infants aged 3-12 weeks we found that significantly more formula than breast-feeding mothers had concerns about stool hardness and had sought professional advice, resulting in both increased use of health care resources and more dietary interventions.

Attitude↗
PubMed1997

Breastfeeding and catch-up growth in infants born small for gestational age.

Postnatal growth was prospectively measured from birth to 1 y in 54 term infants born small for gestational age (SGA), fed either breast milk or a standard term infant formula. Breastfeeding was associated with a 0.36 and 0.64 standard deviation (SD) increase in weight at 2 weeks and 3 months of age, respectively, which persisted beyond the breastfeeding period (0.64 SD at 1 y). Breastfed infants also showed greater catch-up growth in head circumference [SD score (SDS) 0.53 higher at 3 months], and greater body length gain (SDS 0.68 higher at 6 months). This increased growth was independent of potentially confounding obstetric, social and demographic factors. Our findings suggest that breastfeeding may promote faster growth in infants compromised by poor growth in utero. SGA infants may be programmed for a number of adverse outcomes; the possibility that such events are altered by choice of postnatal diet is a key issue for future research.

Anthropometry↗
PubMed1997

Randomized trial of high nutrient density formula versus standard formula in chronic lung disease.

To test the hypothesis that the nutrient intake and growth of infants with chronic lung disease would be improved by providing nutrients in more concentrated form, and that the lower volume would improve respiratory status, 60 preterm infants requiring supplemental oxygen at 28 days of age were randomly assigned a low-density (24 kcal/oz) formula fed at 180 ml/kg/day, or a high-density (30 kcal/oz) formula at 145 ml/kg/day. There was no difference in growth, respiratory outcome, oedema or diuretic requirement between dietary groups. Infants fed the high nutrient density formula had significantly greater total energy (143 vs 134 kcal/kg/day) and protein (3.9 vs 3.6 g/kg/day) intakes, largely because the low-density formula group did not achieve the designated 180 ml/kg/day. In conclusion, use of a high-density formula in infants with chronic lung disease did not improve growth or respiratory outcome, despite a small increase in total energy and protein intake.

Energy Intake↗
PubMed1997

Randomised controlled trial of a synthetic triglyceride milk formula for preterm infants.

AIMS: To test whether use of infant formula containing synthetic structured triglycerides results in: (i) increased palmitate absorption; (ii) increased total fat absorption; (iii) reduction in calcium soap formation in the gut; and hence (iv) increased calcium absorption. METHODS: A randomised study was made of 24 infants comparing three formulas, one containing the synthetic fat Betapol with 74% of palmitate in the 2-position, which was substantially higher than in the two comparison diets (8.4% and 28%). The hypothesised outcomes were tested using balance studies, detailed chemical analysis of stool specimens and dual calcium isotope tracers (44calcium orally and 46calcium intravenously). RESULTS: Three of the four hypotheses were confirmed: use of a formula rich in 2-position palmitate (i) improved palmitate (16:0) and also (18:0) absorption; (ii) reduced the formation of insoluble calcium soaps in the stool; and (iii) improved calcium absorption, determined by the dual tracer technique from 42 (SE 3)% to 57 (7)%. CONCLUSION: Synthetic triglycerides that mimic the stereoisometric structure of those in breast milk may have a valuable role in the design of formulas used for preterm infants in neonatal intensive care units.

Animals↗