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Biomedical subjects

D Mulvin

Publications and source records attributed to D Mulvin.

At least 19 recordsLinked to original sources
PubMed2003

Technical report. Intra-operative ultrasound-guided needle localization for impalpable testicular lesions.

AIMS: To describe a new technique of intra-operative ultrasound-guided needle localization of impalpable intratesticular lesions. MATERIALS AND METHODS: Three patients with impalpable testicular lesions identified on ultrasound underwent needle localization under ultrasound guidance. The procedure was performed in the operating theatre under general anaesthetic using a 7.5-8 MHz linear array probe and a portable ultrasound machine. Under direct guidance, a 21 G needle was placed through the centre of the lesion allowing resection and immediate frozen section analysis. RESULTS: In two patients malignancy was confirmed and an orchidectomy was performed. In one patient a benign lesion was detected obviating the need for orchidectomy. CONCLUSION: Patients presenting with impalpable testicular lesions can pose a diagnostic dilemma and orchidectomy is often performed. We describe an ultrasound-guided intra-operative localization technique enabling direct pathological examination so surgical approach can be re-evaluated in the presence of a benign lesion. This is particularly important in the case of a solitary testicle in order to preserve testicular function.

Adult↗
PubMed2003

Joseph-Frédéric-Benoît Charrière: master cutler and instrument designer.

Modern surgery owes its development to the innovations and skill of those craftsmen in the early 19th Century. Joseph-Frédéric-Benoît Charrière was a Parisian Cutler of renowned fame. He pioneered many developments in ether administration, urologic and other general surgical instrumentation. He also made profound modifications to the syringe, haemostat and aneurysm clip. Charrière, most importantly, developed the French (Fr) or Charrière (Ch) gauge system used in sizing catheters and endoscopic equipment (1 Charr. = 0.333 mm). His contributions were widespread and are still evident today.

Anesthesia↗
PubMed2002

Distribution of vascular endothelial growth factor (VEGF) in prostate disease.

Vascular endothelial growth factor (VEGF) is a heparin-binding polypeptide growth factor. It is a potent mitogen for endothelial cells. Immunohistochemical localisation of VEGF was performed on 25 moderate to poorly differentiated stage T4 M+ prostate cancer specimens and 30 benign prostatic hyperplasia (BPH) specimens. A positive result was indicated by area staining >25% and +2 or +3 staining intensity. Positive epithelial staining was observed in 50% of BPH specimens and 56% of cancer specimens, while positive stromal staining was observed in 73% of BPH specimens and 30% of cancer specimens. This may reflect an active role for stromal VEGF in the pathological process of BPH.

Endothelial Growth Factors↗
PubMed2001

Validity of PSA, free/total PSA ratio and complexed/total PSA ratio measurements in men with acute urinary retention.

The reliability of serum prostate specific antigen (PSA) measurements in men with acute urinary retention is unclear. Total PSA, free and complexed PSA were measured, and the free/total (f/t) PSA and complexed/total (c/t) PSA ratios calculated, prior to catheterisation and at 48 and 72 h post-catheterisation in 39 men with acute retention. Subsequent histology showed 12 patients had prostate cancer and 27 benign prostatic hypertrophy. Serum free and total PSA fell following catheterisation, while complexed PSA rose during the first 48 h then subsequently fell. The f/t PSA and c/t PSA ratios provided the best discrimination at 48-72 h with 100% sensitivity and 75-82% specificity.Prostate Cancer and Prostatic Diseases (2001) 4, 167-172.

Journal Article↗
PubMed2000

Obituaries

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Journal Article↗
PubMed2000

The detection of prostate cells by the reverse transcription-polymerase chain reaction in the circulation of patients undergoing transurethral resection of the prostate.

OBJECTIVE: To determine whether prostate cells are disseminated into the circulation of patients after transurethral resection of the prostate (TURP), as assessed by a reverse transcription-polymerase chain reaction (RT-PCR) assay for prostate specific antigen (PSA) mRNA. PATIENTS AND METHODS: Fifty-one patients, comprising 34 with benign prostatic hyperplasia (BPH) and 17 with prostate cancer who were undergoing routine TURP, had blood samples taken before and 30 min after surgery. The blood mononuclear cell layer was isolated by density-gradient centrifugation and total RNA extracted. Complementary DNA was synthesized by RT of the RNA. The target PSA sequence was amplified by PCR with specific PSA primers and the product detected on agarose-gel electrophoresis with ethidium bromide staining. RESULTS: Five patients (all with prostate cancer) were positive on PSA RT-PCR before surgery and remained positive after TURP. Of the remaining 46 patients, five (11%; three with BPH and two with cancer) changed from a negative to a positive result after TURP. CONCLUSION: In a proportion of patients TURP causes the dissemination of prostate cells into the circulation which are then detectable by RT-PCR of PSA mRNA.

Aged↗
PubMed1999

Functional characterization of alpha1-adrenoceptor subtypes in longitudinal and circular muscle of human vas deferens.

The alpha1-adrenoceptor subtype(s) mediating contraction to noradrenaline in longitudinal and circular muscle of human epididymal vas deferens was studied using competitive antagonists. The effects of the alkylating agents, phenoxybenzamine and chloroethylclonidine were also investigated. Noradrenaline evoked concentration-dependent contractions of longitudinal and circular muscle with comparable potencies (pD2; 5.6 and 5.5 respectively). The contractions in longitudinal and circular muscle respectively were inhibited by prazosin (pA2, 8.6 and pKB, 9.2), 5-methylurapidil (pKB, 8.7 and 9.1) and less potently by spiperone (pA2, 7.1) or BMY 7378 (pKB, 6.3 and 6.6). Contractions of the circular but not longitudinal muscle was comparatively insensitive to pretreatment with phenoxybenzamine. In contrast pretreatment with chloroethylclonidine reduced the contractions in both muscle types and also enhanced phenoxybenzamine-sensitivity in longitudinal but not circular muscle. The results suggest that contractions evoked by noradrenaline in both muscle types of human vas deferens is mediated via activation of alpha1-adrenoceptors with pharmacological profile of the alpha1A-subtype. However the involvement of alpha1A-adrenoceptor variants, such as the hypothesised alpha1L-subtype may underlie the differential effects of phenoxybenzamine in longitudinal and circular muscle. Factors contributing to chloroethylclonidine-sensitivity are discussed.

Adrenergic alpha-Agonists↗
PubMed1999

Angiogenic peptides in prostatic disease.

OBJECTIVE: To determine the value of measuring serum concentrations of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in patients with benign prostatic hyperplasia (BPH), advanced and localized prostate cancer, and thus assess the role of angiogenesis factors as markers of malignancy and the formation of metastasis. PATIENTS AND METHODS: Serum was obtained from 106 suitable patients who attended a routine clinic during the study period. A histological diagnosis was confirmed for each patient and a bone scan was positive in those with metastatic disease. The level of serum prostate specific antigen (PSA) was measured and the serum concentrations of VEGF and bFGF measured using a quantitative sandwich immunoassay technique. RESULTS: There was a significant difference (1.6-fold) in the serum concentration of bFGF between patients with local and advanced prostate cancer (P=0.006), but there was no significant difference for either of the growth factors between patients with BPH and metastatic prostate cancer (Mann-Whitney test). CONCLUSION: The serum levels of VEGF and bFGF could not be used to distinguish benign from malignant prostatic disease; the serum PSA level is of more value than either, but the serum concentration of bFGF may be of some value in differentiating patients with local and advanced malignancy.

Aged↗
PubMed1999

Influence of investigative and operative procedures on serum prostate-specific antigen concentration.

We determined the effect of cystoscopy (flexible and rigid), transrectal ultrasonography (with and without needle biopsy of the prostate) and transurethral resection of the prostate or bladder tumour on the serum prostate-specific antigen (PSA) concentration. Samples were taken from 60 men before and up to 14 days following these procedures. Flexible cystoscopy did not result in a significant increase in serum PSA concentration, with a median increase of 0.1 microgram/L (P > 0.05). Small but statistically significant increases in serum PSA levels 1 day post-procedure were observed following rigid cystoscopy and transrectal ultrasound without biopsy. The median increase in serum PSA concentration following rigid cystoscopy was 0.15 microgram/L (P = 0.04) and following transrectal ultrasound was 0.3 microgram/L (P = 0.01). In both cases the serum PSA level had normalized by 2 days post-procedure. Transurethral resection of bladder tumours resulted in a variable rise in serum PSA, with a median increase of 2.6 micrograms/L after 1 day, which returned to normal over 7-14 days. Ultrasound-guided needle biopsy of the prostate and transurethral resection of the prostate produced significant increases in serum PSA levels, which took up to fourteen days to return to normal. The median increase in serum PSA following needle biopsy was 6.0 micrograms/L and following transurethral resection of the prostate (TURP) was 13 micrograms/L. Samples for PSA measurement may safely be taken within 24-48 h of flexible cystoscopy and transrectal ultrasonography (TRUS) providing prostatic biopsy is not carried out. For other procedures it is necessary to wait for at least 14 days to ensure that false positive PSA results are not obtained.

Aged↗
PubMed1998

The release of free prostate specific antigen into the circulation during transurethral resection of the prostate: kinetics and interaction with serum protease inhibitors.

OBJECTIVE: To determine the nature and extent of the release of prostate specific antigen (PSA) and its interaction with its plasma protein-derived inhibitors after transurethral resection of the prostate (TURP). MATERIALS AND METHODS: Twenty-three consecutive patients undergoing routine TURP for benign prostatic hyperplasia had blood samples taken pre-operatively and then post-operatively at 8-hourly intervals for 24 h. Further samples were obtained at 48 and 72 h post-operatively. Serum free and total PSA were determined by immunofluorometric assay. The major plasma protein inhibitors for PSA were also determined by immunoassay. RESULTS: The mean free and total PSA fractions increased significantly post-operatively with levels greatest immediately after surgery. There was also a gradual increase in the complexed PSA fraction, reaching a peak at 48 h. The concentration of the major serum inhibitors of PSA (alpha-1-antichymotrypsin and alpha-2-macroglobulin) also declined immediately after surgery. CONCLUSION: Increases of serum total PSA in patients after TURP are caused by increases in the free PSA fraction. The exponential decline in free PSA concentrations is consistent with the complexing of PSA with its protease inhibitors present in the plasma. The formation of this complex suggests that the free PSA released into the circulation at the time of TURP is the enzymatically active form.

Humans↗
PubMed1997

Ischemic damage to the prostate during cardiac surgery: a clinical model.

BACKGROUND: To determine if altered tissue perfusion during cardiac surgery results in ischemic tissue damage to the prostate, as suggested by a rise in prostatic-specific antigen (PSA). METHODS: Twenty-nine male patients undergoing elective coronary artery bypass grafting were studied. Ten male patients undergoing elective gastrointestinal surgery served as controls. PSA levels were determined preoperatively and six hourly intervals postoperatively for 48 hr. All patients underwent urethral catheterization at induction of anesthesia. RESULTS: All patients (100%) who had undergone cardiac bypass surgery showed rises in serum PSA during 48 hr of postoperative follow-up. At the 6-hr postoperative interval, the mean PSA was significantly different from the mean baseline value (paired two tailed Student's t test, P < 0.001) in 27 of the 29 (93%) patients. In contrast, the PSA values in the 10 gastroenterological controls did not change at 6 hr (P > 0.2) or during the next 48 hr. One patient in the cardiac group showed a very marked elevation in serum PSA of greater than 50 times normal preoperative levels. CONCLUSIONS: Statistically significant rises in PSA levels are seen following coronary bypass surgery. This rise may be caused by ischemic nontrauma related damage to the prostate and suggests a possible pathophysiological mechanism for the clinically episodic symptoms of prostatism seen in elderly men.

Coronary Artery Bypass↗
PubMed1997

High-intensity focused ultrasound in the treatment of benign prostatic hyperplasia.

OBJECTIVE: To assess the role of high-intensity focused ultrasound (HIFU) in the treatment of symptomatic benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Thirteen patients (mean age 65 years, range 58-74) were treated with HIFU as part of a phase-2 clinical trial and evaluated prospectively using the International Prostate Symptom Score, uroflowmetry, and transrectal and transabdominal ultrasonography to determine prostate size and post-void residual urine volume, respectively. The results and the patients' satisfaction were assessed at regular intervals for 2 years. RESULTS: The new procedure was learned quickly and was easy to perform. Symptom scores decreased from a mean of 23 before treatment to 5 after 12 months and 7 after 2 years. There was an initial improvement in flow rates but they then declined. The size of the prostate and the post-void residual volume were both decreased after treatment. CONCLUSIONS: The treatment is safe, easy to implement and was effective in substantially reducing symptom scores in these few patients. However, we would not encourage its use as an alternative to other well established treatment modalities until it has been assessed fully in a randomized trial.

Aged↗
PubMed1994

Transurethral microwave thermotherapy versus transurethral catheter therapy for benign prostatic hyperplasia.

Transurethral microwave thermotherapy (TUMT) is a single outpatient treatment for benign prostatic hyperplasia. It produces good symptomatic relief but minimal objective improvement in mean flow rates. We wished to evaluate the placebo effect of the transurethral catheter. We evaluated 40 patients with outflow obstruction, 20 had TUMT for 1 h and 20 had a catheter placed in the urethra without treatment for 1 h. Urinary flow rates improved in both groups (12.8-14.6 with TUMT, 10.0-12.4 with catheter). Significant reduction from pretreatment values occurred in symptom scores and postvoid residual urine volume in both groups following treatment. The subjective results of TUMT and the placebo effect seen in the catheter group cast doubt on our understanding of the mechanism of action of TUMT.

Humans↗
PubMed1992

Endothelial cell proliferation is induced by radiation in cultured explants of human urothelium and oesophageal mucosa.

Normal oesophageal mucosa obtained during upper abdominal surgery or urothelium obtained from kidney transplants was placed in explant culture and exposed to 60Co gamma radiation after 48 h. Cultures were maintained for two to six weeks after exposure and were monitored at various intervals for the development of features associated with malignant transformation. Endpoints examined included proliferation rate, frequency of proliferating cells, cell type distribution and degree of differentiation of the different cell types. The results indicate that following exposure to gamma rays (2.5-10 Gy) an increased overall growth rate of the surviving cells can be observed 2-4 weeks later. Analysis of the results using autoradiography confirms that a higher level of cell proliferation occurs in treated cultures than in the control untreated cultures. When the distribution of different cell types in the culture is examined, the increase in growth can be seen to be due to greatly increased numbers of endothelial cells. These proliferated over the surface of the epithelial cells and are more strongly positive for endothelial cells markers than endothelial cells occurring in control cultures. The degree of differentiation of endothelial cells into capillary like structures is also more apparent in carcinogen treated cultures. Foci expressing both epithelial and endothelial markers also occur. The results suggest that exposure of tissue fragments to radiation stimulates the growth and development of endothelial cells in resulting cell cultures. The effect may be due to a direct action of the treatment on the endothelial cells but it is more likely that it results from a secondary effect mediated by traumatic response of damaged epithelial cells.

Cell Division↗
PubMed1992

Lung tolerance to hyperthermia by in vivo perfusion.

In vivo isolated lung perfusion is a novel technique for targeting anticancer therapy to the lung while avoiding systemic toxicity as normal lung toxicity from the antitumour therapy becomes the limiting factor. This study was performed to investigate the effects of hyperthermia on lung function in an intact animal model in which both acute and subacute toxicity could be monitored. Dogs underwent in vivo isolated lung perfusion. A control group was perfused to a lung temperature of 37 degrees C (group 1) and two other groups were treated in an identical manner except that the perfusion temperature was 43 degrees-44.8 degrees C in group 2 and greater than 45 degrees C in group 3. An assessment of lung injury was performed pre-perfusion, immediately post-perfusion and 2 weeks post-perfusion by measurement of extravascular lung water (Qev), serotonin uptake and wet weight to dry weight ratio. Our findings showed that the lung was tolerant to hyperthermia up to about 44 degrees C for 1 h. Analysis of 4 animals who survived perfusion above 3/44.0 degrees C showed a highly significant decrease in serotonin uptake between pre- and post-perfusion values (82.4 +/- 1.2 vs 40.4 +/- 3.9, P less than 0.02); at 2 weeks serotonin uptake had returned to normal in all 3 dogs. Fulminating pulmonary oedema developed at temperatures over 45 degrees C. Serotonin uptake may be a sensitive predictor of thermal lung injury.

Animals↗
PubMed1992

Chest roentgenographic techniques for demonstrating human lung tumour xenografts in nude rats.

Roentgenographic techniques were investigated for imaging orthotopic lung tumours in anaesthetized nude rats endobronchially implanted with human lung cancer cells. A conventional radiographic unit with a dual-screen, double-emulsion film mammographic receptor produced images preferable to those from a mammographic unit because of superior resolution. Typical exposure factors were 300 mA, 29 kVp, and 17 ms at a focus-film distance of 76 cm with a 2.11 by 2.41 mm effective focal spot and inherent filtration of 1.2 mm aluminium. Sensitivity for tumour detection was 0.93 for 59 animals with pathologically proved tumours and 0.96 for 54 animals with tumours larger than 4 mm or 50 mg. For 24 pathologically tumour-free animals, specificity was 1.00. For 55 animals radiographically judged to have tumours, positive predictive value was 1.00. For all 83 animals, accuracy was 0.95. This technique effectively demonstrates orthotopic human lung tumours in nude rats and should be useful for noninvasive monitoring of tumour presence, location, size, and changes in size.

Adenocarcinoma↗