PubMed Health⌕ Search

Biomedical subjects

S Dolan

Publications and source records attributed to S Dolan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Initial experience with breast reconstruction using the transverse rectus abdominis myocutaneous flap: a study of 45 patients.

Breast conserving surgery for breast cancer has led to an increased interest in reconstruction following mastectomy. The transverse rectus abdominis myocutaneous flap has been proven to give good results in terms of restoration of body symmetry with near normal contour and consistency. Furthermore, immediate reconstruction has the advantage of a single procedure with less psychological morbidity, and reduction in hospital stay and overall complication rate. The aim of this study was to review our experience with the transverse rectus abdominis myocutaneous flap procedure an initial series of 45 patients. The overall complication rate of 27% is similar to that reported in the literature, with no total flap loss and nine patients with partial flap loss. There was no delay in commencement of adjuvant chemotherapy or radiotherapy and we believe our ability to detect local recurrence has not been compromised. We consider that immediate breast reconstruction is now an integral part of the surgical treatment of breast cancer.

Adult↗
PubMed1999

Laparoscopic cholecystectomy: experience with 303 patients over the initial four years.

A total of 303 patients underwent attempted laparoscopic cholecystectomy (LC) over a four-year period by two consultant surgeons or a senior trainee under their supervision. The procedure was completed in 291 with a conversion rate to open cholecystectomy of 3.9% and a median postoperative length of stay of two days, range zero to nine days. In eighteen patients the indication for LC was failure of symptoms to settle, two of whom required conversion (11.1%). Diathermy dissection was avoided in Calot's triangle and dissection started at the junction of Hartmann's pouch and cystic duct with full mobilisation of this area prior to clip application. Pre-operative endoscopic retrograde cholangiopancreatography ERCP was performed in patients suspected of having common bile duct stones without routine intra-operative cholangiography. There was one death in this series (0.3%) and an overall complication rate of 6.3 %. There was no incidence of either bile duct injury or leak. LC can be performed with a low complication rate with attention to careful dissection technique in the region of Calot's triangle.

Adolescent↗
PubMed1998

The Arthromitus stage of Bacillus cereus: intestinal symbionts of animals.

In the guts of more than 25 species of arthropods we observed filaments containing refractile inclusions previously discovered and named "Arthromitus" in 1849 by Joseph Leidy [Leidy, J. (1849) Proc. Acad. Nat. Sci. Philadelphia 4, 225-233]. We cultivated these microbes from boiled intestines of 10 different species of surface-cleaned soil insects and isopod crustaceans. Literature review and these observations lead us to conclude that Arthromitus are spore-forming, variably motile, cultivable bacilli. As long rod-shaped bacteria, they lose their flagella, attach by fibers or fuzz to the intestinal epithelium, grow filamentously, and sporulate from their distal ends. When these organisms are incubated in culture, their life history stages are accelerated by light and inhibited by anoxia. Characterization of new Arthromitus isolates from digestive tracts of common sow bugs (Porcellio scaber), roaches (Gromphodorhina portentosa, Blaberus giganteus) and termites (Cryptotermes brevis, Kalotermes flavicollis) identifies these flagellated, spore-forming symbionts as a Bacillus sp. Complete sequencing of the 16S rRNA gene from four isolates (two sow bug, one hissing roach, one death's head roach) confirms these as the low-G+C Gram-positive eubacterium Bacillus cereus. We suggest that B. cereus and its close relatives, easily isolated from soil and grown on nutrient agar, enjoy filamentous growth in moist nutrient-rich intestines of healthy arthropods and similar habitats.

Animals↗
PubMed1998

Where do cancer patients die? Ten-year trends in the place of death of cancer patients in England.

Although studies have found that 50-70% of cancer patients would prefer to die at home, there has been a trend towards the hospitalization of the dying in many countries. No study has attempted to analyse the changes in place of death in detail. The aim was to analyse the 10-year trends in place of death of cancer patients, by region and by diagnosis, within England. To do this, data on the place of death and patients' characteristics were derived from death registrations for all cancer deaths between the years 1985-94. We examined trends in the place of death for the whole of England, for each region separately and for the main cancer diagnoses. The results show that there were over 1.3 million death registrations from cancer during the 10 years. The mean age increased over the period from 69.9 years in 1985, to 71.3 years in 1994. The percentage who died in a UK National Health Service (NHS) hospital or nursing home fell gradually from 58% (1985) to 47.3% (1994), while the percentage who died in non-NHS hospitals, nursing homes, hospices and communal establishments increased. The percentage who died at home fell slightly but steadily between 1985 and 1992 from 27% to 25.5% and since then increased slightly to 26.5% in 1994. The percentage of home deaths was lowest in the two Thames regions (less than 25%) and highest in the West Midlands, Anglia and Oxford (over 29%). These differentials were maintained across age groups and diagnoses. Older people and women were less likely to die at home than younger people and men. Significant trends showing an increase in home deaths were found in two regions: North Thames and South Thames. Patients with cancers of the lung, colorectum, respiratory organs, bone or connective tissue and lip, oral cavity and pharynx were more likely to die at home (over 29% in 1994) than patients with cancers of the (breast (women, 25% in 1994) or the lymphatic or haematological system 16% in 1994). It can be concluded that the trend towards a reducing home death rate from cancer in England appears to have halted, although this varies between regions. This has implications for primary care services. Although hospital is still the most common place of death from cancer, the percentage of cancer patients who die in hospital is reducing. The largest rise is in the increasing use of hospices and communal establishments, including residential and nursing homes. Given the ageing population, this trend is likely to continue.

Adult↗
PubMed1997

Hospital admissions for asthma in east London: associations with characteristics of local general practices, prescribing, and population.

OBJECTIVE: To determine the relative importance of appropriate prescribing for asthma in explaining high rates of hospital admission for asthma among east London general practices. DESIGN: Poisson regression analysis describing relation of each general practice's admission rates for asthma with prescribing for asthma and characteristics of general practitioners, practices, and practice populations. SETTING: East London, a deprived inner city area with high admission rates for asthma. SUBJECTS: All 163 general practices in East London and the City Health Authority (complete data available for 124 practices). MAIN OUTCOME MEASURES: Admission rates for asthma, excluding readmissions, for ages 5-64 years; ratio of asthma prophylaxis to bronchodilator prescribing; selected characteristics of general practitioners, practices, and practice populations. RESULTS: Median admission rate for asthma was 0.9 (range 0-3.6) per 1000 patients per year. Higher admission rates were most strongly associated with small size of practice partnership: admission rates of singlehanded and two partner practices were higher than those of practices with three or more principals by 1.7 times (95% confidence interval 1.4 to 2.0, P < 0.001) and 1.3 times (1.1 to 1.6, P = 0.001) respectively. Practices with higher rates of night visits also had significantly higher admission rates: an increase in night visiting rate by 10 visits per 1000 patients over two years was associated with an increase in admission rates for asthma by 4% (1% to 7%). These associations were independent of asthma prescribing ratios, measures of practice resources, and characteristics of practice populations. CONCLUSIONS: Higher asthma admission rates in east London practices were most strongly associated with smaller partnership size and higher rates of night visiting. Evaluating ways of helping smaller partnerships develop structured proactive care for asthma patients at high risk of admission is a priority.

Adolescent↗
PubMed1997

High-frequency oscillatory ventilation for adult respiratory distress syndrome--a pilot study.

OBJECTIVE: To evaluate the safety and effectiveness of high-frequency oscillatory ventilation using a protocol designed to recruit and maintain optimal lung volume in patients with severe adult respiratory distress syndrome (ARDS). SETTING: Surgical and medical intensive care units in a tertiary care, military teaching hospital. DESIGN: A prospective, clinical study. PATIENTS: Seventeen patients, 17 yrs to 83 yrs of age, with severe ARDS (Lung Injury Score of 3.81 +/- 0.23) failing inverse ratio mechanical conventional ventilation (PaO2/FiO2 ratio of 68.6 +/- 21.6, peak inspiratory pressure of 54.3 +/- 12.7 cm H2O, positive end-expiratory pressure of 18.2 +/- 6.9 cm H2O). INTERVENTIONS: High-frequency oscillatory ventilation was instituted after varying periods of conventional ventilation (5.12 +/- 4.3 days). We employed lung volume recruitment strategy that consisted of incremental increases in mean airway pressure to achieve a PaO2 of > or = 60 torr (> or = 8.0 kPa), with an FiO2 of < or = 0.6. MEASUREMENTS AND MAIN RESULTS: High-frequency oscillator ventilator settings (FiO2, mean airway pressure, pressure amplitude of oscillation [delta P] frequency) and hemodynamic parameters (cardiac output, oxygen delivery [DO2]), mean systemic and pulmonary arterial pressures, and the oxygenation index (oxygenation index = [FiO2 x mean airway pressure x 100]/PaO2) were monitored during the transition to high-frequency oscillatory ventilation and throughout the course of the high-frequency protocol. Thirteen patients demonstrated improved gas exchange and an overall improvement in PaO2/FiO2 ratio (p < .02). Reductions in the oxygenation index (p < .01) and FiO2 (p < .02) at 12, 24, and 48 hrs after starting high-frequency oscillatory ventilation were observed. No significant compromise in cardiac output or DO2 was observed, despite a significant increase in mean airway pressure (31.2 +/- 10.3 to 34.0 +/- 6.7 cm H2O, p < .05) on high-frequency oscillatory ventilation. The overall survival rate at 30 days was 47%. A greater number of pretreatment days on conventional ventilation (p < .009) and an entry oxygenation index of > 47 (sensitivity 100%, specificity 100%) were associated with mortality. CONCLUSIONS: High-frequency oscillatory ventilation is both safe and effective in adult patients with severe ARDS failing conventional ventilation. A lung volume recruitment strategy during high-frequency oscillatory ventilation produced improved gas exchange without a compromise in DO2. These results are encouraging and support the need for a prospective, randomized trial of algorithm-controlled conventional ventilation vs. high-frequency oscillatory ventilation for adults with severe ARDS.

Adolescent↗
PubMed1996

Differential effect of whisker trimming on excitatory and inhibitory transmission in primary somatosensory cortex of the adult rat in vivo.

The effects of sensory deprivation on excitatory and inhibitory activity in the primary somatosensory cortex were studied in the adult rat. Excitatory and inhibitory transmission generated by whisker stimulation, and neuronal responsiveness to iontophoretically applied excitatory amino acids were recorded. Whisker input deprivation, through whisker trimming for a median of 24 days, resulted in a significant decrease in excitatory transmission to surround whisker stimulation. In contrast, the response magnitude to principal whisker stimulation remained unchanged. However, the response latencies to principal whisker and surround whisker stimulation were significantly reduced, which led to altered temporal response distributions in deprived cells. Neurons deprived of sensory input were significantly less responsive to glutamate, N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionate and kainate. Following deprivation, no change was observed in cortical inhibitory transmission measured 30-200 ms post-stimulus. These results show that excitatory transmission (including excitatory amino acid receptor function) is altered by adult whisker deprivation.

Animals↗
PubMed1996

Tracheal gas insufflation combined with high-frequency oscillatory ventilation.

OBJECTIVES: To determine the efficacy of tracheal insufflation delivered by two different catheter designs on CO2 elimination when used in conjunction with high-frequency oscillatory ventilation. DESIGN: A nonrandomized before and after trial. Each animal served as his own control. SUBJECTS: Ten mongrel dogs weighing 20.9 +/- 1.9 kg. Four animals were assigned to a normal lung group and six animals underwent lung injury by large volume saline lavage. INTERVENTION: Permissive hypercapnia was allowed to occur by selecting oscillator settings that would lead to alveolar hypoventilation. Proximal mean airway pressure was kept constant. Tracheal gas was insufflated at 1 cm above the carina for 30 min periods at gas flows of 5 to 15 L/min. MEASUREMENTS AND MAIN RESULTS: Carinal pressure, hemodynamic parameters (cardiac output, mean arterial pressure, pulmonary artery occlusion pressure), and gas exchange parameters (PaCO2, PaO2, PaO2/FIO2, shunt fraction, D O2) were measured. For the normal dogs, at catheter flow of 15 L/min; the forward thrust catheter increased carinal pressure and Pao2/FIO2 BY 30% (p<.003) and 105% (p<.005), respectively. The forward thrust catheter reduced Paco2 by 40% (p<.04). The reverse thrust catheter increased PaO2/FIO2 by 102% (p<.001) and decreased pressure and PaCO2 by 44% (p<.001) and 34% (p<.003), respectively. For the injured dogs, at catheter flow rate of 15 L/min, the forward thrust catheter increased carinal pressure, PaO2, and PaO2/FIO2 by 6% (p<.001), 23% (p<.001), and 24% (p<.02), respectively. The forward thrust catheter reduced PaCO2 by 29% (p<.002). The reverse thrust catheter increased PaO2 and PaO2/FIO2 both by 11% (p<.02) and reduced carinal pressure and PaCO2 by 23% (p<.001) and 18% (p<.002), respectively. CONCLUSIONS: Tracheal gas insufflation is capable of improving oxygenation and ventilation in acute lung injury when combined with high-frequency oscillatory ventilation. The addition of this second gas flow at the level of the carina raises or lowers distal airway pressure, the magnitude of which is dependent on the direction and rate of gas flow. The beneficial effects of tracheal gas insufflation may be tempered by the long-term effects of altering distal airway pressure; lowering distal airway pressure may lead to atelectasis, whereas raising distal airway pressure may lead to an auto-positive end-expiratory pressure (auto-PEEP) effect.

Animals↗
PubMed1995

Performance of osteopathic medical school graduates on the American Osteopathic Board of Internal Medicine certifying examinations 1985 to 1994.

This study examined the trends in the medical knowledge of osteopathic internal medicine residents in American Osteopathic Association-approved residency programs during a recent 10-year period and compared these trends with the declining medical knowledge observed for internal medicine residents graduated from allopathic medical schools and trained in allopathic residency programs. These results demonstrate a similar pattern of declining medical knowledge that appears to have leveled off during the past few years of the study. These trends occurred among candidates from both large and smaller training institutions. Various factors may have contributed to these observations.

Certification↗
PubMed1994

Synthesis and structure-activity relationships of a series of penicillin-derived HIV proteinase inhibitors: heterocyclic ring systems containing P1' and P2' substituents.

As an extension of our earlier work based upon a single penicillin-derived thiazolidine moiety we have found that the decahydroisoquinoline grouping, also present in Ro 31-8959, is an effective replacement for one of the thiazolidine units in C2 symmetric penicillin-derived dimers. Reaction of racemic epoxide 6 with [3S-[3 alpha, 4a alpha, 8a alpha]]-decahydro-N-(1,1-dimethylethyl)-3- isoquinolinecarboxamide gave diasteroisomers 34a and 34b. The stereochemistry of the hydroxyl grouping of 34a was determined to be (S). Reaction of the amines derived from 34a and 34b with thiazolidine 8a gave 50 and 51, respectively. Compound 50 was a potent inhibitor of HIV proteinase (IC50 = 23 nM) with antiviral activity against HIV-1 in vitro (EC50 C8166 cells = 50 nM). However, a poor pharmacokinetic profile in the dog for compound 50 and its analogues, in keeping with earlier studies on penicillin-derived dimers in three species, precluded their development as potential antivirals.

Amino Acid Sequence↗
PubMed1994

Mineral interactions in rats fed AIN-76A diets with excess calcium.

The effects of moderate increases in dietary calcium on maternal and foetal mineral interactions were studied in Charles River CD/VAF Plus rats. Female rats were given 0.50, 0.75, 1.00 or 1.25% dietary calcium as calcium carbonate in AIN-76A diets for 6 wk before mating, during mating and for 20 days of gestation. Inductively coupled argon plasma-atomic emission spectrometry was used to determine mineral levels in the tissues of non-pregnant rats after 42 days on the diets, in the tissues of pregnant rats on day 20 of gestation and in the whole body of day-20 foetuses. The femurs of the non-pregnant and pregnant rats had a dose-related linear increase in calcium content. In livers of the non-pregnant rats, dose-related linear increases in the phosphorus, zinc and magnesium content were observed, but there was a dose-related decrease in the iron content. There were dose-related linear decreases in the iron and copper contents of the kidneys from the non-pregnant rats. In pregnant rats dose-related linear decreases were observed in the iron content of the liver and in the zinc, iron and magnesium contents of the kidney. The foetuses from rats given a moderate increase in dietary calcium had dose-related decreases in the whole-body contents of phosphorus, iron, copper and magnesium.

Animals↗