Biomedical subjects
S White
Publications and source records attributed to S White.
Local anaesthetic endonasal endoscopic laser dacryocystorhinostomy: analysis of patients' acceptability and various factors affecting the success of this procedure.
BACKGROUND AND OBJECTIVES: Endonasal endoscopic laser dacryocystorhinostomy is now a well established, effective approach to relieve nasolacrimal duct obstruction. Whereas attempts have been made to comment on the efficacy of the procedure, no study has been conducted to evaluate the acceptability of this procedure by those at the receiving end, ie, the patients. An attempt has been made in the present study to critically evaluate the procedure from the point of view of patients' acceptability and also to evaluate certain factors which may influence the success rate of this procedure. PATIENTS AND METHODS: Forty-six eyes from 40 patients underwent endonasal endoscopic laser dacryocystorhinostomy, performed by the same surgeon, over a period of 15 months. Various aspects of the procedure were evaluated by patients by filling out a simple questionnaire (Figure 1). In addition to recording patients' views, success of the procedure was confirmed by performing a postoperative sac washout in the clinic. Patients were also subdivided according to their age, duration of symptoms and history of previous surgical intervention. The data were statistically analysed using chi-square tests with the Yates correction. RESULTS: The percentage of patients who declared themselves completely cured was 65.22%. A partial resolution was felt by 23.91% of patients and no improvement was reported by 10.87% of patients. Forty-two out of the 46 eyes (91.3%) achieved anatomical success by the procedure, as shown by a postoperative sac washout performed in the clinic. Some of them, however, did not have complete resolution of their symptoms perhaps due to an additional factor of lacrimal pump dysfunction in these patients. During the procedure 60.86% of eyes felt no discomfort at all whereas 39.14% of eyes felt some discomfort at some point of time during the procedure (Table 1). When directly asked 86.12% of patients recommended the procedure (implying that the procedure had some good effect on their quality of life), 8.33% of patients did not recommend it and 5.55% of patients made no comments. Various factors affecting the success of this procedure were analysed (Table 2) and it was found that eyes which had no previous surgical intervention showed a complete cure rate which was significantly higher than that seen in eyes which had some sort of previous intervention (P = 0.0003); eyes with a short (<6 mths) duration of symptoms showed significantly higher success rates (P = 0.0098) in comparison to that shown by eyes with longer (>6 mths) duration of symptoms; and younger patients (<50 yrs) had a complete resolution rate much higher than patients over 50 yrs of age (P = 0.0309). CONCLUSION: The present study clearly shows that endonasal endoscopic laser DCR is an effective procedure, well tolerated and recommended by the patients. Discomfort during the procedure is not a major problem. Younger patients, with no previous surgical intervention and with short duration of symptoms are likely to be benefited the most. Though success rates are higher with external DCR, endonasal endoscopic laser DCR offers certain advantages over the external approach while keeping the option of external DCR open, if needed at a later date.
Obesity: under-diagnosed and under-treated in hospital outpatient departments.
OBJECTIVE: This study investigated whether medically significant obesity (body mass index > 30 kg/m2) is recognised effectively in hospital outpatient departments and how those identified as obese are subsequently managed. DESIGN: A retrospective analysis of patients' hospital records (rheumatology n = 108, cardiology n = 257, orthopaedic n = 250) established the reported prevalence of obesity and subsequent referral patterns. In addition, BMI was measured prospectively on a separate cohort (rheumatology n = 188, cardiology n = 203, orthopaedic n = 179) to determine the true prevalence. RESULTS: Generally, obesity management appeared minimal and inconsistent. Retrospective analysis revealed an apparently low rate of obesity (4% cardiology, 5% rheumatology and 3% orthopaedics), whilst the true prevalence was found to be 30% for cardiology, 25.1% for orthopaedics and 20.2% for rheumatology. Although this appears to show a large disparity between the apparent and the true prevalence, it is impossible to establish precisely the degree of under-estimation, as the lack of height measurements (14% only) in the retrospective sample affects the reliability of the apparent prevalence. Further comparison with the general population showed obesity to be particularly common in men attending cardiology clinics. CONCLUSION: An outpatient clinic consultation could be a useful starting point for integrating obesity and disease management, by helping to identify obesity, initiate appropriate referrals and assist in obesity education.
Completeness of data entry in three cancer surgery databases.
AIMS: Clinical databases are regularly used for audit and research purposes. The accuracy of data input is critical to the value of these tools, but little is known about the factors which influence the completeness of data recording. The aim of this study was to evaluate the influences affecting completeness of data recording in computerized clinical databases of cancer treatment. METHODS: Data omission rates in three databases dealing with management of breast, colorectal and gastro-oesophageal cancers were calculated. The effects of (a) type of record; (b) nature of data and (c) training required to interpret data were evaluated by univariate and multivariate analyses. RESULTS: The overall data omission rate was 21.9% (upper GI 27.6%, breast 19.6%, colorectal 32.7%, P=0.13). For different categories of data, omission rates varied from 0% to 55%. Fields requiring a 'text field' or 'numerical' entry, or containing demographic data, data required for the process of care or data which required no interpretation were associated with low omission rates. Clinical data, and fields requiring a 'yes/no' response were associated with high omission rates (45 and 48% respectively). Clinical data and data relating to patient demographic details were independently associated with high and low omission rates respectively (odds ratios for significant missing data 86.9 and 1 respectively). CONCLUSION: Clinical data are poorly captured by current cancer surgery databases. Reasons for the poor completion of fields requiring input by clinical staff, particularly availability of time and training, and prioritization of work, should be addressed. Re-design of databases to ensure that data entry is simple and unambiguous may improve accuracy.
Retrograde subintimal angioplasty via a popliteal artery approach.
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Endovascular repair of multiple peripheral aneurysms via a dual approach involving a venous graft conduit.
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Intake estimation of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in salmon: the inclusion of uncertainty.
Dioxins and dioxin-like PCBs are given toxic equivalency factors (TEFs) in order to calculate the combined toxic equivalence (TEQ) of these contaminants in a sample of food. This study calculates the probability of an average consumer exceeding the recommended tolerable daily intake of 1-4 pg WHO-TEQ kg(-1) bw day(-1) as the amount of salmon in the diet is increased. Probabilistic risk analysis is used to account for the known uncertainties in this calculation. When the TEF uncertainty was excluded with no salmon consumption, the background dietary intake ranged from 1.36 to 1.78 pg TEQ kg(-1) bw day(-1). A weekly consumption of three standard salmon portions resulted in a 36% chance of exceeding the upper limit of the TDI. Inclusion of the TEF uncertainty increased the background dietary intake range from 2.1 to 4.4 pg TEQ kg(-1) bw day(-1), and the weekly consumption of one salmon portion resulted in a 79% chance of the average consumer exceeding the upper TDI. The most important factors contributing to the uncertainty in these results were, in order of magnitude, the TEF for PCB 126 and the sampling uncertainty (sample size) followed by the measurement uncertainty of PCB 126. We recommend that it is more important to increase sample size and produce more precise estimates in the TEF than to improve analytical accuracy.
Banning pregnant netballers--is this the answer?
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Elevated K(+) induces myristoylated alanine-rich C-kinase substrate phosphorylation and phospholipase D activation in glomerulosa cells.
Elevated extracellular potassium concentrations ([K(+)](e)) are known to stimulate aldosterone secretion from adrenal glomerulosa cells in vivo and in vitro. The mechanism is thought to involve depolarization-elicited activation of voltage-dependent calcium channels and an increase in calcium influx. Until now protein kinase C (PKC) was thought not to play a role in the steroidogenic response to elevated [K(+)](e). In this report, we provide evidence in bovine adrenal glomerulosa cells to suggest that elevated [K(+)](e) increases PKC activity, as shown by an enhancement in the phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS). Elevated [K(+)](e)-induced MARCKS phosphorylation was delayed and transient and was not the result of a local production of angiotensin II (AngII). MARCKS phosphorylation in response to elevated [K(+)](e) was not accompanied by phosphoinositide hydrolysis but was inhibited by a selective PKC inhibitor. Elevated [K(+)](e) also activated phospholipase D (PLD) in a delayed but sustained manner. We propose that the observed PLD activation mediates the elevated [K(+)](e)-induced MARCKS phosphorylation via PKC, although other factors may modulate this phosphorylation event.
Breastfeeding in HIV-1-positive mothers.
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Effects of helpers on juvenile development and survival in meerkats.
Although breeding success is known to increase with group size in several cooperative mammals, the mechanisms underlying these relationships are uncertain. We show that in wild groups of cooperative meerkats, Suricata suricatta, reductions in the ratio of helpers to pups depress the daily weight gain and growth of pups and the daily weight gain of helpers. Increases in the daily weight gain of pups are associated with heavier weights at independence and at 1 year of age, as well as with improved foraging success as juveniles and higher survival rates through the first year of life. These results suggest that the effects of helpers on the fitness of pups extend beyond weaning and that helpers may gain direct as well as indirect benefits by feeding pups.
mik1(+) G1-S transcription regulates mitotic entry in fission yeast.
In the fission yeast Schizosaccharomyces pombe Mik1p, in combination with Wee1p, is an important inhibitor of mitosis through direct phosphorylation of Cdc2p. Here we present the observation that mik1(+) is transcribed during G1- and S-phase in normally dividing cells. mik1(+) transcription is regulated by the MCB-DSC1 system, which controls expression of other genes at the G1-S interval. mik1(+) is shown to be an important target of MCB-DSC1 as it is epistatic for the mitotic delay phenotype displayed in cdc10-C4 cells, which are mutated in a component of DSC1. The mitotic delay in cdc10-C4 cells is bypassed by cdc2-1w, suggesting that mik1(+) acts directly on cdc2(+), with no checkpoint function involved. Thus, mik1(+) represents a new type of MCB-DSC1 regulated gene in fission yeast, whose gene product is exclusively expressed during G1- and S-phase to prevent premature mitosis during this cell cycle stage.
ANPs effect on MARCKS and StAR phosphorylation in agonist-stimulated glomerulosa cells.
Atrial natriuretic peptide (ANP) is a cardiac hormone that inhibits aldosterone secretion induced by all physiologic agonists. The purpose of this study is to explore ANP-induced changes in the phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS) and the steroidogenic acute regulatory protein (StAR), in AngII or K(+)-stimulated glomerulosa cells. The data show that ANP completely inhibits the phosphorylation of MARCKS and partially inhibits that of StAR in cells stimulated with K(+). ANP also partially inhibits MARCKS phosphorylation but does not affect StAR phosphorylation in cells stimulated with AngII. These effects appear to be cGMP-independent and at least partially dependent on inhibition of protein kinase C (PKC). To our knowledge, this is the first report of ANP modulating either MARCKS or StAR phosphorylation in [(32)P]-labeled cells. The data also support the hypothesis that ANP inhibits aldosterone secretion acting as a step involved in cholesterol transport to the mitochondria.
Renal proximal tubule function is preserved in Cftr(tm2cam) deltaF508 cystic fibrosis mice.
1. Changes in proximal tubule function have been reported in cystic fibrosis patients. The aim of this study was to investigate proximal tubule function in the Cftr(tm2cam)deltaF508 cystic fibrosis (CF) mouse model. A range of techniques were used including renal clearance studies, in situ microperfusion, RT-PCR and whole-cell patch clamping. 2. Renal Na(+) clearance was similar in wild-type (1.4 +/- 0.3 microl min(-1), number of animals, N = 12) and CF mice (1.6 +/- 0.4 microl min(-1), N = 7) under control conditions. Acute extracellular volume expansion resulted in significant natriuresis in wild-type (7.0 +/- 0.8 microl min(-1), N = 8) and CF mice (9.3 +/- 1.4 microl min(-1), N = 9); no difference between genotypes was observed. 3. In situ microperfusion revealed that fluid absorptive rate (Jv) was similar under control conditions between wild-type (2.2 +/- 0.4 nl mm(-1) min(-1), n = 10) and CF mice (1.9 +/- 0.3 nl mm(-1) min(-1), n = 11). Addition of a forskolin-dibutyryl cAMP (db-cAMP) cocktail to the perfusate caused no significant change in Jv in either wild-type (2.6 +/- 0.7 nl mm(-1) min(-1), n = 10) or Cftr(tm2cam)deltaF508 mice (2.0 +/- 0.5 nl mm(-1) min(-1), n = 10). 4. CFTR expression was confirmed in samples of outer cortex using RT-PCR. However, no evidence for functional CFTR was obtained when outer cortical cells were stimulated with protein kinase A or forskolin-db-cAMP using whole-cell patch clamping. 5. In conclusion, no functional deficit in proximal tubule function was found in Cftr(tm2cam)deltaF508 mice. This may be a consequence of a lack of whole-cell cAMP-dependent Cl(-) conductance in mouse proximal tubule cells.
Differential effects of agonists of aldosterone secretion on steroidogenic acute regulatory phosphorylation.
The steroidogenic acute regulatory (StAR) protein mediates cholesterol transport within the mitochondria, and its phosphorylation is believed to be required for steroidogenesis. Increased extracellular potassium concentrations (K(+)), angiotensin II (AngII), and adrenocorticotropic hormone (ACTH) induce aldosterone secretion from bovine adrenal glomerulosa cells. We hypothesized that, although these agonists act via different signaling pathways, StAR phosphorylation should be common to their action. We studied the effects of K(+), AngII, and ACTH, at concentrations that yield comparable secretory responses, on StAR phosphorylation. All three agents induced significant increases in StAR phosphorylation although the response to ACTH was less than that of AngII and K(+). In cells stimulated with the protein kinase C (PKC) agonist 12-tetradecanoylphorbol 13-acetate (TPA), the Ca(2+) channel agonist BAY K8644, and the adenylate cyclase agonist forskolin, TPA caused a small but statistically significant increase in StAR phosphorylation while BAY K8644 and forskolin had no significant effect. Interestingly, the combination of TPA and BAY K8644 produced a larger increase in StAR phosphorylation than the agents alone. We conclude that in cultured bovine adrenal glomerulosa cells the PKC signaling pathway is most effective at inducing StAR phosphorylation but that there is no simple correlation between this event and aldosterone production.
Ropivacaine with or without clonidine improves pediatric tonsillectomy pain.
OBJECTIVE: To determine if preemptive analgesia with ropivacaine hydrochloride with or without clonidine hydrochloride decreases pain and hastens recovery after tonsillectomy. DESIGN: Prospective, randomized, triple-blinded trial. SETTING: University referral center; pediatric ambulatory practice. PARTICIPANTS: Sixty-four children, aged 3 to 15 years, undergoing tonsillectomy. INTERVENTIONS: Patients received injections in the tonsillar fossae of isotonic sodium chloride, ropivacaine, or ropivacaine plus clonidine prior to tonsil excision. MAIN OUTCOME MEASURES: Visual analogue (pain) scale scores at rest and when drinking, opioid use, recovery time to normal activity, and incidence of symptoms such as otalgia. RESULTS: Pain was reduced on postoperative day 0 in the ropivacaine-treated and ropivacaine plus clonidine-treated groups as compared with the isotonic sodium chloride-treated group (P<.05). Pain was also decreased in the ropivacaine plus clonidine-treated group on postoperative days 3 and 5 (P<.05). Intravenous narcotic use was decreased on day 0 in the ropivacaine-treated and ropivacaine plus clonidine-treated groups (P<.05). Cumulative codeine use was similar at day 3 for all patients, but was decreased at day 5 in the ropivacaine plus clonidine-treated group (P<.05). The incidence of otalgia decreased from 89% (16/18) in the isotonic sodium chloride-treated group to 63% (12/19) in the ropivacaine-treated and 61%(11/18) in the ropivacaine plus clonidine-treated groups (P<.01). Recovery to normal activity was shortened from 8.1 +/- 1.6 days to 5.8 +/- 2.9 days (mean +/- SD) in the isotonic sodium chloride-treated and ropivacaine plus clonidine-treated groups, respectively (P =.03). CONCLUSION: Preincisional injection of ropivacaine with clonidine prior to tonsillectomy has a preemptive analgesic effect that outlasts the local anesthetic and decreases pain, opioid use, and the time to return to normal activity.
The role of DSC1 components cdc10+, rep1+ and rep2+ in MCB gene transcription at the mitotic G1-S boundary in fission yeast.
In this paper, we describe the transcription profile of a group of genes at the G1-S boundary of fission yeast in synchronously dividing mitotic cells, under a variety of different conditions. This transcription profile is unaffected in cells where either cdc10+ or cdc10-C4 are constitutively overexpressed. In contrast, overexpression of either rep1+ or rep2+ results in constitutive expression of MCB-regulated genes, suggesting that these polypeptides have important regulatory properties in controlling MCB transcription. Finally, we examine the pattern of MCB-regulated transcription in cells where the G1 period is extended. Surprisingly, we find that the wee1-50 mutation causes MCB transcription throughout the cell cycle, whereas cells re-fed after nitrogen starvation have normal expression patterns. The implications of these observations for understanding MCB-regulated transcription are discussed.
Is there a relationship between cognitive dysfunction and systemic inflammatory response after cardiopulmonary bypass?
BACKGROUND: The systemic inflammatory reaction (SIR) is assumed to be one of the factors that causes cerebral dysfunction after cardiopulmonary bypass (CPB). The aim of the present study was to evaluate the relationship between the SIR and postoperative cognitive performance at 5 days and 3 months. METHODS: One hundred patients undergoing coronary artery bypass grafting were studied. Inflammatory markers and markers of coagulation and fibrinolysis were determined at several time points during and after the operation. Correlation analysis between maximum levels of the different markers and early and late performance was performed. RESULTS: No overall association was found between the maximum levels of the inflammatory markers and early and late function. CONCLUSIONS: Notwithstanding limitations of statistical power established markers of systemic inflammatory reaction showed no relationship with outcome at 5-day or 3-month follow-up in this subset of patients.