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Biomedical subjects

A Webb

Publications and source records attributed to A Webb.

At least 91 records · Page 5Linked to original sources
PubMed1996

Provision of emergency contraception by nurses: a way forward to increased access.

OBJECTIVES: The objectives of the study were to assess the suitability of a service for provision of emergency hormonal contraception by nurses. METHODS: Retrospective analysis was carried out of data obtained from the case records of 500 consecutive women who attended ABACUS (a city center-based family planning clinic in Liverpool, UK) for emergency contraception during the 7th and 9th months of the first year (1994) of the service. Similar data were collected for 100 consecutive women during 1 month of the third year (June 1996). The number of women who received emergency hormonal contraception was noted. In particular, details pertaining to the reasons for referral to the doctor and the trend of referrals were noted. RESULTS: The results indicate that during the first year the nurses independently issued emergency hormonal contraception to 37% of the women. They referred the remaining 63% to the medical staff. One-third of referrals were for ongoing contraception, especially oral contraception. Another third of referrals appeared to be due to 'nurse anxiety', as no medical or other cause was found for these referrals. During the third year, nurses dispensed emergency hormonal contraception to 64% of women. Among the remaining 36% of women who were referred to the doctor, 19% needed hormonal contraception. Referral reflecting 'nurse anxiety' significantly declined (1%) compared to the first year of service. CONCLUSIONS: Ongoing contraception, particularly initiation of oral contraception, was one of the main reasons for referral during the first year. Referral due to 'nurse anxiety' significantly declined with continued experience and may have reflected initial anxiety and the learning curve. With increased experience over the first 2 years, the outcome of this service showed encouraging improvement. The nurses now dispense emergency hormonal contraception to a majority of women.

Adolescent↗
PubMed1996

History of 'tropical nursing' in East London: the Dreadnought experience.

In the latter years of the nineteenth century, the 'Dreadnought' Seamen's Hospital (previously the Infirmary of the Greenwich Hospital) became London's centre of excellence for the healthcare of 'seamen of all nations' (many had 'tropical' and/or sexually-transmitted diseases); this followed a 50-year period (1821-1870) during which three successive hospital ships (anchored on Greenwich Reach) had been used for this purpose' (1). Numerous mariners 'afloat and ashore' therefore owed their lives (and good health) to the skill of the physicians and surgeons based there, but equally (and perhaps more) important was the care and devotion of the nursing staff (2).

Disease↗
PubMed1995

On-line NMR detection of amino acids and peptides in microbore LC.

The combination of liquid chromatography (LC) and nuclear magnetic resonance (NMR) offers the potential of unparalleled chemical information from analytes separated from complex mixtures. However, the application of LC-NMR has been hindered by poor detection sensitivity. We develop a theoretical model for predicting signal-to-noise ratio (SNR) performance while scaling NMR detection cells for flowing experiments. The model includes the effects of separation parameters, coil geometry, and NMR acquisition parameters on SNR performance. Although the detector cell should be as large as possible to ensure adequate efficiency for a given separation, reducing the detector cell volume does not significantly degrade SNR. For example, our model predicts a 2-fold reduction in SNR for a 400-fold reduction in cell volume. The results of static NMR measurements of amino acids and peptides in a 50-nL-volume cell (approximately 1 microgram of each) demonstrate the performance of such a small-volume NMR microcell. Using this 50-nL detector cell with microbore LC, two-dimensional LC-NMR chromatograms are shown for amino acid and peptide separations.

Amino Acid Sequence↗
PubMed1995

A case of paternal uniparental disomy for chromosome 11.

We report a case of paternal uniparental disomy for chromosome 11 that presented as severe intrauterine growth retardation. Autopsy following intrauterine death also revealed aberrant intestinal rotation and hypospadias. Chromosome analysis of direct preparations from placental biopsy showed an abnormal 47,XY,+11 karyotype. Analysis of long-term cultures from the placenta revealed 46,XY/47,XY,+11 mosaicism. Fluorescence in situ hybridization (FISH) studies on interphase nuclei confirmed trisomy 11 in multiple placental sites but detected only disomic cells in fetal skin. Investigation using microsatellite polymorphisms demonstrated paternal isodisomy at loci D11S909, D11S956, and D11S488, and paternal heterodisomy at locus D11S928.

Adult↗
PubMed1995

Squamous oesophageal cancer can be downstaged using protracted venous infusion of 5-fluorouracil with epirubicin and cisplatin (ECF).

21 patients with squamous oesophageal carcinoma were treated with a new regimen designed in our unit and effective in treating gastric adenocarcinoma, consisting of continuous venous infusion of 5-fluorouracil for up to 24 weeks (200 mg/m2/day) with epirubicin (50 mg/m2) and cisplatin (60 mg/m2) every 3 weeks. 12 patients (57%) had an objective response. The median relapse free period was 7 months, median survival from start of chemotherapy 8.4 months, and median survival from diagnosis, 14 months. Symptomatic improvements were reported by 10/11 patients with pain (91%), 8/9 with anorexia (89%), 8/10 with reflux (80%) and 10/14 with dysphagia (71%). Grade 3 or 4 toxicity was reported by 11 patients: 5 had haematological toxicity, 3 vomiting, 2 infection and 1 diarrhoea. One patient developed peripheral neuropathy, 1 renal impairment and another peripheral vascular disease. Following chemotherapy, surgery was attempted in 5 patients. One remains well 3 years on, 2 had macroscopic clearance of tumour but died of postoperative complications. In 2, disease was irresectable. This regimen of moderate toxicity is effective at improving symptoms in the majority of patients. In some patients, tumours are briefly downstaged so that inoperable tumours may become operable.

Adult↗
PubMed1995

Adjuvant chemotherapy for oesophagogastric cancer with epirubicin, cisplatin and infusional 5-fluorouracil (ECF): a Royal Marsden pilot study.

Previous trials of adjuvant chemotherapy for oesophagogastric cancer have shown only modest or no improvement in survival. However, the regimens used in these studies produce low response rates in patients with advanced disease. ECF is a new regimen which results in higher response rates and may therefore be more effective in the adjuvant setting. Twenty-nine patients who had undergone a potentially curative resection for oesphagogastric carcinoma were treated with ECF [epirubicin 50 mg m-2 and cisplatin 60 mg m-2 for 18 weeks]. The median age was 52.5 years. Three patients had oesophageal tumours, 14 had tumours of the oesophagogastric junction (OGJ) and 12 had gastric tumours. All were adenocarcinomas apart from one undifferentiated carcinoma. One patient had stage I disease, nine stage II, 17 stage II and two stage IV. The mean number of chemotherapy cycles per patient was 5.2 (range 2-8). The median follow-up was 8.4 months (1.5-36.3 months). Eleven patients relapsed during follow-up (38%). One patient had an anastomotic recurrence and ten patients distant metastases. Overall 3 year survival was 61.5% (95% confidence interval 42-79); 3 year survival in stage II was 50% (21.2-86.3) and in stage III 65.6% (40-86). Chemotherapy was well tolerated, with grade 3/4 toxicity as follows: leucopenia 13.5%, nausea and vomiting 10%, diarrhoea 3.5%, infection 3.5% and thrombocytopenia 3.5%. There were no treatment-related deaths. We conclude that ECF can be administered safely as adjuvant treatment to patients with surgically resected gastro-oesophageal carcinoma. The results, especially in patients with stage III disease, are encouraging and support the investigation of this regimen within a prospective randomised trial.

Adenocarcinoma↗
PubMed1995

Clearance of gentamicin during cardiac surgery.

Treatment with an aminoglycoside plus flucloxacillin is commonly used to prevent wound infection and endocarditis after cardiac surgery. Cardiopulmonary bypass, blood transfusion and the lack of a steady state greatly affect handling of gentamicin. Urinary gentamicin excretion is not predictable in terms of preoperative risk factors possibly because there is no clear relationship between serum levels and gentamicin clearance. A study was performed to determine whether the existing prophylactic regimen gave adequate serum levels during surgery and to compare renal excretion of gentamicin and the trough serum levels. Ten patients received gentamicin (1.5 mg/kg at the start of surgery followed by 80 mg tds for 2 days) and flucloxacillin 500 mg qds for 2 days. Serum and urinary concentrations of gentamicin were assayed during surgery and in the early postoperative period. The median apparent serum half-life during the first 8 h was 2.5 h (95%CI 1.7-3.2 h). The median gentamicin clearance was 37 mL/min(95%CI 23-64 mL/min) and the creatinine clearance 85 mL/min (95%CI 72-210 mL/min). Serum levels remained above 1 mg/L during surgery but urinary concentrations varied between 0.4 and 364 mg/L (median 70 mg/L). At 24 h (but not 8 or 16 h), trough serum levels appeared to be related to the amount of gentamicin excreted but the relationship was not quite statistically significant (P = 0.057). Despite the effects of cardiopulmonary bypass, therapeutic serum gentamicin levels were maintained during surgery and reduced renal excretion in the postoperative period was associated with raised levels.

Cardiac Surgical Procedures↗
PubMed1995

Antibiotic prophylaxis in cardiac surgery: factors associated with potentially toxic serum concentrations of gentamicin.

Aminoglycosides are commonly used with flucloxacillin in the prevention of wound infection and endocarditis after cardiac surgery. Earlier studies suggested that the use of aminoglycosides is associated with a small but significant rise in serum creatinine. A regression analysis was performed to identify the preoperative and postoperative factors of importance in determining serum gentamicin concentrations. Serum assays might then be confined to those at particular risk of elevated serum levels. Patients received gentamicin 1.5 mg/kg at the start of surgery followed by 80 mg tds for two days in addition to flucloxacillin. Trough and peak serum gentamicin concentrations were assayed on the first and second days after surgery and urine concentrations were measured with each full catheter bag. Patient characteristics, drug therapy, operation, fluid balance and routine investigations were recorded. A total of 95 of 104 patients were evaluable. Linear discriminant analysis of factors selected by forward stepwise regression identified ten of the 15 patients with subsequent elevated gentamicin concentrations, by using age, and preoperative serum creatinine, systolic blood pressure and serum aspartate transaminase. After operation, factors such as serum creatinine, the quantity of frusemide administered in 24 h, and the integral of the systolic blood pressure over 24 h identified 12 of the 15 patients. However, no satisfactory model could predict urinary concentrations. The discriminant function using preoperative factors prospectively identified 11 of 12 patients with elevated trough levels from a total of 101 further patients. Postoperative gentamicin concentrations cannot reliably be predicted from patient characteristics. Trough assays should be performed or prophylactic courses limited to 24 h.

Adult↗
PubMed1995

The prognostic value of CEA, beta HCG, AFP, CA125, CA19-9 and C-erb B-2, beta HCG immunohistochemistry in advanced colorectal cancer.

BACKGROUND: Evaluation of the prognostic significance of a group of tumour markers and their ability to predict response to chemotherapy may allow better targeting of palliative treatment in advanced colorectal cancer. PATIENTS AND METHODS: Using a prospectively acquired database of 377 patients (pts) with advanced colorectal adenocarcinoma, the prognostic significance of serum CEA (342 pts), beta HCG (203 pts), AFP (208 pts), CA125 (150 pts), CA-19-9 (76 pts) as well as C-erb B-2 (197 pts). Serum markers were taken prior to 5-FU based chemotherapy and immunohistochemistry was performed on diagnostic samples RESULTS: Tumour markers of poor prognostic significance in the univariate analysis were CEA > or = 5 micrograms/l (p = 0.006; median survival (MS 59 weeks vs 38 weeks) and CA125 > or = 35 U/ml (p = 0.01 MS 51 weeks vs. 30 weeks). Tumour markers elevated at greater than 10 times the normal value which correlated with a poor prognosis were CEA (p = 0.001; MS 47 weeks vs. 35 weeks), Serum beta HCG (p < 0.0001; MS 44 weeks vs. 7 weeks) and CA125 (p < 0.0001; MS 38 weeks vs. 15 weeks). Poor performance status ( > 2) and poorly differentiated tumour histology were also correlated to poor survival. In the multivariate analysis, tumour markers of independent poor prognosis were CEA > or = 5 micrograms/l (Hazard Ratio (HR) 1.8; 95% Confidence Internal (CI) 2.8-1.2), CEA > or = 50 micrograms/l (HR 1.6; CI 2.1-1.2), CA125 > or = 35 U/ml (HR 1.5; CI 2.3-1.0), CA 125 > or = 350 U/ml (HR 5.0; CI 9.6-2.6) and serum BHCG > or = 0 IU/l (HR 11.7; CI 30-4.5). Poor performance status (HR 6.7-5.0) and poorly differentiated histology (HR 2.8-1.0) were the other important factors in the model. No pretreatment tumour marker correlated with response to chemotherapy. CONCLUSIONS: This is the largest prognostic study of each tumour marker in advanced disease and it clarifies previous conflicting reports. Serum AFP, CA19-9 and immunohistochemical stains beta HCG and C-erb B-2 have no prognostic significance. Serum CEA, beta HCG, CA125 in advanced colorectal cancer prior to chemotherapy do convey an independent poor prognosis which may reflect not just tumour burden but aggressive biology.

Adenocarcinoma↗
PubMed1995

Cisplatin and protracted venous infusion 5-fluorouracil (CF)--good symptom relief with low toxicity in advanced pancreatic carcinoma.

PURPOSE: The combination of protracted venous infusion (PVI) 5-FU with moderate dose cisplatin was evaluated in patients with advanced pancreatic cancer. PATIENTS AND METHODS: Sixty-three patients with locally advanced or metastatic disease were treated with cisplatin (60 mg/m2 every 21 days) and PVI 5-FU (300 mg/m2/day) for a maximum of 24 weeks. All patients had histologically/cytologically confirmed tumour. Radiological response was assessed by CT scanning and toxicity, performance status and symptomatic response were assessed 3 weekly. RESULTS: The objective response rate was 16% with two radiological complete responses. The median survival was 7.6 months with a 1-year survival of 33% and a median progression-free survival of 6.6 months. Patients who had local disease only had a median survival of 14.8 months with a 1-year survival of 52%. Thirty-four percent of patients had an improvement in performance status on treatment and specific symptom response rates were weight loss 71%, dysphagia 100%, nausea and vomiting 70%, pain 60%, anorexia 50%, and reflux 81%. Chemotherapy was well tolerated with grade 3 or 4 toxicity being nausea/vomiting 5%, diarrhoea 7%, infection 4%, stomatitis 2%, plantar palmar syndrome 2%, anaemia 14%, leucopenia 5, neutropenia 10% and thrombocytopenia 8%. CONCLUSIONS: The CF regimen provides good symptomatic palliation with low toxicity in patients with advanced pancreatic cancer.

Adenocarcinoma↗
PubMed1995

Goal-directed therapy with dopexamine, dobutamine, and volume expansion: effects of systemic oxygen transport on hepatic ultrastructure in porcine sepsis.

OBJECTIVES: Can the hepatic structural deterioration that occurs during peritonitis be attenuated by increasing cardiac output and oxygen consumption (VO2)? Do the agents used to achieve these increases have any characteristic affects on these hepatic structural changes? DESIGN: Randomized, prospective, observational animal study. SETTING: Research laboratory of a university medical school. SUBJECTS: Twenty-five Middle White adolescent pigs, weighing 25 to 30 kg, divided into five groups. INTERVENTIONS: A thermodilution flotation catheter was advanced into the pulmonary artery. Additional catheters were inserted into the jugular, portal, and hepatic veins, and into the femoral artery. Ultrasound flow probes were placed around the portal vein and the hepatic artery. A metabolic cart was attached to the ventilator. Baseline measurements were made and cardiac output was increased by > 25% by administering either dobutamine (10 micrograms/min), dopexamine (10 micrograms/kg/min), or colloid. A control group had its cardiac output maintained at its baseline value. Peritonitis was induced in the four groups by contamination with cecal content and maintained for 6 hrs. Hepatic tissue was then removed for ultrastructural analysis and the animals were killed. MEASUREMENTS AND MAIN RESULTS: Before infection, cardiac output, VO2, and hepatic blood flow were increased in the three treatment groups. In the dobutamine and dopexamine groups, oxygen delivery increased, but decreased in the volume group. Mean arterial pressure increased in the dobutamine and dopexamine groups, but in the volume group, mean arterial pressure was maintained. Six hours after infection, cardiac output and VO2 had further increased in the dobutamine and volume groups, but both variables had decreased in the dopexamine group. After infection in the control group, cardiac output had decreased, although oxygen delivery and VO2 increased. There were no significant differences between hepatic hemodynamic or oxygen transport variables in any of the groups during the infection period. Hepatic ultrastructure was well maintained in the dopexamine group, while considerable deterioration was seen in the volume and control groups. In the dobutamine group, hepatic deterioration was greater than in the other three groups. CONCLUSIONS: Increasing cardiac output and VO2 before and during infection was only protective when dopexamine was administered. Dobutamine infusion was associated with greater hepatic deterioration than that effect seen in either the control or volume groups.

Adrenergic beta-Agonists↗
PubMed1995

Impact of protracted venous infusion fluorouracil with or without interferon alfa-2b on tumor response, survival, and quality of life in advanced colorectal cancer.

PURPOSE: The aim of this study was to investigate the effects of adding interferon alfa-2b (IFN) to protracted venous infusion fluorouracil (PVI 5-FU) from the start of treatment in patients with advanced colorectal cancer. PATIENTS AND METHODS: Patients who attended our unit with histologically confirmed advanced colorectal cancer were randomized to receive either PVI 5-FU 300 mg/m2/d via Hickman line, and IFN 5 MU subcutaneously three times weekly, or PVI 5-FU alone. Treatment was given for a maximum of two 10-week blocks, with a 2-week gap for reassessment of all parameters. Quality of life (QL) was measured by the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) pretreatment and every 6 weeks thereafter. RESULTS: A total of 160 patients were randomized, with 155 eligible for assessment. Radiologic response was observed in 43 patients (28%): 17 of 77 (22%) in the 5-FU-plus-IFN arm (all partial responses [PRs]) and 26 of 78 (33%) in the 5-FU-alone group (complete responses [CRs] and 22 PRs) (difference not significant). Symptomatic improvement occurred in the majority of patients, and equally in both arms: 61% to 80% depending on the symptom. There was no significant difference between the two groups in failure-free survival (median, 161 v 193 days) or overall survival (median, 328 v 357 days). However, patients who received IFN did experience significantly more toxicity in the form of leukopenia (P = .001), neutropenia (P = .04), mucositis (P = .008), and alopecia (P = .0002). There were no toxic deaths and few notable differences in QL between the two arms. CONCLUSION: This study confirms that PVI 5-FU is effective in treating the symptoms associated with metastatic colorectal carcinoma, with only mild to moderate toxicity and maintenance of QL. IFN 5 MU three times weekly does not enhance these palliative benefits.

Adolescent↗
PubMed1995

Guidance of oligodendrocytes and their progenitors by substratum topography.

Oligodendrocyte progenitors arise in subventricular zones and migrate extensively during development before differentiating into mature oligodendrocytes, which myelinate nerve tracts in the central nervous system. We have used microfabricated substrata, containing periodic patterns of contours similar to those of central nervous system axons to assess the influence in vitro of substratum topography on oligodendrocytes isolated from 7 day rat optic nerve. Antiganglioside antibody A2B5 positive oligodendrocyte-type 2 astrocyte progenitors, and galactocerebroside positive and myelin basic protein positive oligodendrocytes, were highly aligned by surface contours as small as 100 nm depth and 260 nm repeat spacing. Rat optic nerve astrocytes also aligned on surface contours, but rat hippocampal and cerebellar neurons were unresponsive. Oligodendrocytes demonstrated enhanced parallel extension of their processes on narrow repeating topography in an arrangement similar to that found in the intact optic nerve. This is in marked contrast to the phenotype displayed by this cell type on planar substrata. Neither oligodendrocytes nor oligodendrocyte-type 2 astrocyte progenitors showed high-order F-actin cytoskeletal networks; thus their alignment on gratings is unlikely to result from deformation of actin cables and focal contacts. In contrast, aligned astrocytes showed striking arrangements of actin stress fibres. These results establish glial cells as potentially the most topographically sensitive cell types within the central nervous system. Furthermore, the topographical pattern inducing maximal alignment of oligodendrocyte lineage cells corresponds to the diameters of single axons within the 7 day optic nerve. Thus the migration of oligodendrocyte-type 2 astrocyte progenitors and axonal ensheathment by oligodendrocytes may be guided by axonal topography within the developing nerve.

Animals↗
PubMed1993

Clotting factors after emergency contraception.

UNLABELLED: Women with a previous history of thromboembolic disease have often been denied oral emergency contraception because of a theoretical concern about increasing their risk of thrombosis. METHODS: Eleven healthy volunteers with regular periods were recruited to the study. A thrombophilia screen was done at the first visit and they each had four measurements of Factor VII and antithrombin III taken at mid-cycle for two cycles. In the third cycle, emergency contraception was given mid-cycle and blood samples were taken 1, 3 and 7 days later. A further four samples were taken during the following cycle and, where the cycle had been significantly foreshortened due to the emergency contraception, a fifth cycle was monitored. The treatment given during the third cycle was the standard Yuzpe regimen of emergency contraception, which consists of 100 micrograms of ethinylestradiol and 500 micrograms of levonorgestrel repeated after twelve hours. RESULTS: There was a wide inter- and intra-subject variation in clotting factors in the observation months. There was no obvious effect noted in the levels of the factors measured after treatment, either in the first week or in the subsequent month(s) of follow-up. CONCLUSIONS: The dosage of ethinylestradiol used in emergency contraception is very shortlived and this study shows no effect on clotting factors. This suggests that ethinylestradiol should not be automatically dismissed in women with previous thromboembolic disease.

Administration, Oral↗
PubMed1993

Microbial degradation of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in soils.

The microbial degradation of tensile test pieces made of poly(3-hydroxybutyrate) [P(3HB)] or a copolymer of 90% 3-hydroxybutyric acid and 10% 3-hydroxyvaleric acid was studied in soils incubated at a constant temperature of 15, 28, or 40 degrees C for up to 200 days. In addition, hydrolytic degradation in sterile buffer at temperatures ranging from 4 to 55 degrees C was monitored for 98 days. Degradation was measured through loss of weight (surface erosion), molecular weight, and mechanical strength. While no weight loss was recorded in sterile buffer, samples incubated in soils were degraded at an erosion rate of 0.03 to 0.64% weight loss per day, depending on the polymer, the soil, and the incubation temperature. The erosion rate was enhanced by incubation at higher temperatures, and in most cases the copolymer lost weight at a higher rate than the homopolymer. The molecular weights of samples incubated at 40 degrees C in soils and those incubated at 40 degrees C in sterile buffer decreased at similar rates, while the molecular weights of samples incubated at lower temperatures remained almost unaffected, indicating that molecular weight decrease is due to simple hydrolysis and not to the action of biodegrading microorganisms. The degradation resulted in loss of mechanical properties. From the samples used in the biodegradation studies, 295 dominant microbial strains capable of degrading P (3HB) and the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer in vitro were isolated and identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗