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Biomedical subjects

C Pitt

Publications and source records attributed to C Pitt.

12 recordsLinked to original sources
PubMed2004

[Transrectal ultrasound-assisted gun-biopsy in the diagnostic of presacral recurrent rectal carcinoma].

Suspected extraluminal recurrence of rectal carcinoma after surgical treatment represents a frequent diagnostic challenge. Clinical history and examination as well as tomographic imaging often do not equivocally settle this tissue. Glucose-PET is an expensive, not universally available test. Early diagnosis is required for both successful operative reintervention aiming at cure and indication to palliative therapy. We performed gun-biopsy of presacral space-occupying lesions in three patients, choosing the ultrasound-guided transrectal approach in three of them. Extraluminal recurrence was proven in one patient. In another patient, anastomotic recurrence was proven by endoscopic biopsy and presacral recurrence ruled out before reoperation. In the third patient, no tumour tissue was found in the samples, as confirmed by his clinical course and by another biopsy after one year. By providing a sufficient amount of tissue for histological examination, ultrasound-guided gun-biopsy allows definite diagnosis in presacral space-occupying lesions and hence represents an important expansion of the diagnostic repertoire in the follow-up of rectal cancer.

Adenocarcinoma↗
PubMed2004

[Pilonidal Sinus -- Primary Closure also in Case of Abscess?].

After excision of pilonidal sinus treatment consists either in open procedure or primary closure. We present the results of 45 consecutive patients (male 29, female 16, age 32 +/- 13 years), who underwent surgery between September 2001 and December 2002. Fourteen patients had simple fistula without infection, 18 had fistulas with putride secretion and 13 had abscess. Primary closure with direct suture was performed in 34 patients (76 %: 13 x simple fistula, 13 x fistula with putride secretion, 8 x abscess). Eleven patients were treated by layopen procedure and secondary wound healing. Wound infection occurred in 13 patients (7 x superficial, 6 x deep). Mean time of postoperative treatment was 15 +/- 3 days after closure and primary healing and 66 +/- 15 days after open proce dure or secondary healing. Mean time out of work was 19 +/- 10 respectively 52 +/- 19 days. A recurrence of fistula occurred in eight patients after primary closure (18 %) and none after open procedure. Also in cases of pilonidal sinus with infection, primary wound closure can be carried out even though the rate of recurrences is higher than after open procedure. A successful primary closure significantly reduces time of illness and time out of work.

Abscess↗
PubMed2001

Adjunctive intravaginal metronidazole for the prevention of postcesarean endometritis: a randomized controlled trial.

OBJECTIVE: To estimate the efficacy of preoperative administration of intravaginal metronidazole for the prevention of postcesarean endometritis. METHODS: This double-masked, placebo-controlled randomized trial included patients of at least 24 weeks' gestation undergoing cesarean deliveries for various indications. Patients were randomized to receive either 5 g of metronidazole gel intravaginally or matching placebo before the initiation of the cesarean. All patients underwent surgical cleansing of the abdomen, and most received prophylactic antibiotics after cord clamping. Patients with chorioamnionitis and/or suspected allergy to metronidazole were excluded. For a two-sided alpha of 0.05 and beta of 0.20 (80% power), 120 subjects were required in each group. The main outcome variable was the incidence of postcesarean endometritis. Secondary outcome variables included presence of febrile morbidity, wound infection, days on antibiotics, and length of postpartum hospitalization. Neonatal outcomes included birth weight, Apgar scores less than 7 at 5 minutes, umbilical arterial pH less than 7.16, admission and length of stay in the neonatal intensive care unit, and length of hospital stay. RESULTS: Of 112 patients receiving metronidazole, eight (7%) developed postcesarean endometritis, compared with 19 of 112 (17%) of those receiving placebo gel (relative risk 0.42, 95% confidence interval 0.19, 0.92). No significant differences were noted between treatment groups with respect to the other outcome variables. CONCLUSION: The preoperative administration of 5 g of intravaginal metronidazole gel appears to reduce the incidence of postcesarean endometritis.

Administration, Intravaginal↗
PubMed2000

Prophylactic amnioinfusion for intrapartum oligohydramnios: a meta-analysis of randomized controlled trials.

OBJECTIVE: To evaluate the effectiveness of intrapartum prophylactic amnioinfusion in pregnancies complicated by oligohydramnios. DATA SOURCES: Randomized controlled trials of prophylactic amnioinfusion in women with oligohydramnios were identified using computerized databases, index reviews, and references cited in original studies and review articles. METHODS OF STUDY SELECTION: We evaluated, abstracted data from, and analyzed randomized studies of prophylactic intrapartum amnioinfusion in women with oligohydramnios. In every study the group allocation was based exclusively on presence of oligohydramnios. Only published studies with clearly documented outcome data were included. The quality of each trial was evaluated for methodology, inclusion and exclusion criteria, adequacy of randomization, amnioinfusion protocols, definition of outcomes, and statistical analyses. The trials were evaluated concerning cesarean deliveries for fetal heart rate (FHR) abnormalities, overall cesarean rates, acidemia at birth, intrapartum fetal heart rate abnormalities, Apgar scores under 7 at 5 minutes, and postpartum endometritis. TABULATION, INTEGRATION, AND RESULTS: Thirty-five studies were identified, of which 14 met the inclusion criteria for this systematic review. They included 1533 patients, 793 in the amnioinfusion group, and 740 controls. Odds ratios (OR) with their 95% confidence intervals (CI) for each outcome were calculated. We calculated an estimate of the OR and risk difference for dichotomous outcomes using random and fixed-effects models. A test of homogeneity was done across studies. Women with oligohydramnios who received intrapartum amnioinfusion had lower incidence of cesarean for FHR abnormalities (OR 0.23; 95% CI 0.15, 0.35). Intrapartum amnioinfusion also was associated with lower overall rates of cesarean deliveries (OR 0.52; 95% CI 0.40, 0. 68), acidemia at birth (OR 0.40; 95% CI 0.30, 0.55), FHR abnormalities during labor (OR 0.24; 95% CI 0.17, 0.34), and Apgar scores under 7 at 5 minutes (OR 0.52; 95% CI 0.29, 0.91). Postpartum endometritis rates were similar among the study groups. CONCLUSION: In the presence of oligohydramnios, prophylactic intrapartum amnioinfusion significantly improves neonatal outcome and lessens the rate of cesarean delivery, without increasing the rate of postpartum endometritis.

Amniotic Fluid↗
PubMed2000

Changes in susceptibility of bovine sperm to in situ DNA denaturation during prolonged incubation at ambient temperature under conditions of exposure to reactive oxygen species and nuclease inhibitor.

Sperm were incubated for up to 9 days in the presence or absence of exogenous hydrogen peroxide, phenylalanine, catalase and aurintricarboxylic acid to assess the influence of reactive oxygen species and inhibition of deoxyribonucleases on sperm chromatin stability. The assessment of sperm DNA susceptibility to in situ acid denaturation by the sperm chromatin structure assay did not detect any difference in chromatin stability between sperm incubated for 9 days under aerobic and anaerobic conditions in a diluent called 14G. Exposure to exogenous hydrogen peroxide under both aerobic and anaerobic conditions and to phenylalanine under aerobic conditions (which produces hydrogen peroxide by a reaction catalysed by the aromatic amino acid oxidase present in sperm) was detrimental to sperm chromatin stability, increasing its DNA susceptibility to in situ acid denaturation over the incubation time. This effect was eliminated if catalase was present in the diluent. Inclusion of the general deoxyribonuclease inhibitor aurintricarboxylic acid in the diluent severely decreased sperm chromatin stability under both aerobic and anaerobic conditions. Aurintricarboxylic acid was mildly cytotoxic, as revealed by viability assessment, under aerobic, but not under anaerobic, incubation conditions. Exogenous hydrogen peroxide, either directly added to the diluent or generated through the enzymatic oxidation of phenylalanine, was detrimental to sperm motility and the integrity of the plasma membrane.

Animals↗
PubMed1999

Replicate and technician variation associated with computer aided bull sperm head morphometry analysis (ASMA).

Associations of abnormal spermatozoa with bull fertility have yielded varying results. Manual methods of analysis are subjective and highly variable within and between technicians, which may account for these differences. Computer-aided sperm head morphometry appears to be a precise method of assessing sperm head dimensions; however, the effects of replication and technician on sperm head morphometry have not been assessed. The objective of this study was to determine the inter- and intra-analysis and technician variation associated with computer-aided bull sperm head morphometry analysis. Semen from 10 bulls was diluted to 200 x 10(6) sperm/mL, and slide smears were prepared and stained using haematoxylin and rose bengal. Each of two technicians analysed 250 images from each slide, 3 times, using computer-aided sperm head morphometry analysis. The morphometric dimensions of area, perimeter, length, width and width/length for individual sperm heads of each analysis were assessed by GLM-ANOVA for effects of bulls, replications and technicians. The coefficient of variation was recorded for each analysis and across replications. The mean coefficients of variation within and between analyses were compared between technicians by GLM-ANOVA. No differences (p > 0.1) between technicians were found between or among bulls for area (29.63 vs. 29.26 micron 2), perimeter (23.73 vs. 23.86 microns), length (8.73 vs. 8.71 microns), width (4.47 vs. 4.46 microns), or width/length (0.51 vs. 0.51). No differences (p > 0.1) between replicates for sperm head dimension were detected within or among bulls for either technician. No intra- or inter-analysis differences (p > 0.1) between technicians on CVs were observed. The mean intra-analysis CVs for all bulls for both technicians were area = 6.9%, perimeter = 4.9%, length = 4.5%, width = 5.6% and width/length = 6.5%. The mean interanalysis CVs for both technicians were area = 3.0%, perimeter = 2.4%, length = 2.0%, width = 2.0%, and width/length = 1.7%. The results indicate that ASMA is a repeatable and objective method of assessing bull sperm head morphometry within and between technicians. No differences between replications were detected, and hence replicate analyses are not necessary to acquire accurate morphometric data.

Animals↗
PubMed1998

Plant-adapted green fluorescent protein is a versatile vital reporter for gene expression, protein localization and mitosis in the filamentous fungus, Aspergillus nidulans.

Green fluorescent protein (GFP) is a useful reporter to follow the in vivo behaviour of proteins, but the wild-type gfp gene does not function in many organisms, including many plants and filamentous fungi. We show that codon-modified forms of gfp, produced for use in plants, function effectively in Aspergillus nidulans both as gene expression reporters and as vital reporters for protein location. To demonstrate the use of these modified gfps as reporter genes we have used fluorescence to follow ethanol-induced GFP expression from the alcA promoter. Translational fusions with the modified gfp were used to follow protein location in living cells; plant ER-retention signals targeted GFP to the endoplasmic reticulum, whereas fusion to the GAL4 DNA-binding domain targeted it to the nucleus. Nuclear-targeted GFP allowed real-time observation of nuclear movement and division. These modified gfp genes should provide useful markers to follow gene expression, organelle behaviour and protein trafficking in real time.

Aspergillus nidulans↗
PubMed1996

Computer automated morphometric analysis of bull sperm heads.

Morphological type classification of spermatozoa is an important component of the modern semen evaluation; however, current methods of analysis are subjective and highly variable between technicians. To reduce the subjectivity and thus variability of sperm morphology assessment, computer automated sperm head morphology analysis (ASMA) has been developed. Previous studies have shown the importance of standardizing ASMA procedures to optimize accuracy. The objective of this study was to standardize ASMA procedures for evaluating bull sperm heads. Semen from 10 fertile bulls was used to standardize procedures for optimal analysis of bull spermatozoa. Sample preparation methods, sperm staining methods and microscopic magnifications were compared. Semen samples that were diluted to a standard concentration of 200 x 10(6) sperm/ml were more efficiently analyzed than raw samples. A modified GZIN staining procedure, incorporating rose bengal as an acrosomal stain, was used for accurate ASMA at a magnification of x 60. The mean morphometric measurements for all bulls were the area (27.30 microM), perimeter (25.36 microM), length(8.65 microM), width(4.40 microM) and width/length (0.50). Within the analyses, coefficients of variation ranged from 3.45% for length to 8.52% for area. The ASMA system correctly digitized sperm heads 97% of the time. Results of this study indicate that bull sperm heads can be accurately analyzed using current standard procedures of ASMA technology.

Journal Article↗
PubMedDate not supplied

Effects of cryopreservation on bull sperm head morphometry.

Artificial insemination using cryopreserved semen is a common management tool of the contemporary livestock producer. However, cryopreservation is detrimental to sperm function and fertility, killing some 50% of the spermatozoa during the process. Prediction of cryopreservation damage from prefreeze samples remains elusive. Computer-automated sperm head morphometry was used in this study to determine the effects of cryopreservation on bovine sperm head morphometry. Semen was collected from 18 bulls and was divided. One portion was extended to 200 x 10(6) sperm/ml and a microscope slide was prepared, while the remaining portion was cryopreserved in a Triscitrate-yolk extender. After thawing, the cryopreserved samples were prepared on microscope slides. All slides were air dried and were stained with hematoxylin and rose bengal. The morphometric dimensions for length, width, width/length, area, and perimeter for a minimum of 200 sperm heads were analyzed from each slide by computer-aided sperm head morphometry analysis, and the mean measurements were recorded. Bull sperm heads were significantly (P < 0.01) smaller in cryopreserved spermatozoa than in the companion extended samples for length (8.56+/-0.07 vs. 8.63+/-0.08 microm), width (4.39+/-0.05 vs. 4.48+/-0.05 microm), area (28.42+/-0.07 vs. 29.14+/-0.08 microm), and perimeter (23.33+/-0.21 vs. 23.70+/-0.23 microm) for all bulls. Width/length was also different (0.513 vs. 0.519). In addition, differences (P < 0.05) were found within 14 of 18 bulls for at least four of the morphometric parameters. The percent change in measures after cryopreservation were correlated (P < or = 0.05) to the variability of the extended sample. Variations in sperm head measurements were lower (P < or = 0.05) in extended samples of the four bulls in which no changes occurred than in extended samples of the remaining 14 bulls. These data suggest that the variability in sperm head measurements of individual bulls, or ejaculates, may be an indicator of sperm cryosurvivability.

Animals↗