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Biomedical subjects

S Carrier

Publications and source records attributed to S Carrier.

11 recordsLinked to original sources
PubMed1995

Intraperitoneal versus extraperitoneal insufflation of carbon dioxide as for laparoscopy.

In order to compare the effects of intraperitoneal and extraperitoneal insufflation of CO2, we obtained blood gas measurements and chest radiographs in dogs during insufflation into three sites: the peritoneal cavity alone, the retroperitoneal space with communication into the peritoneal cavity, and the retroperitoneal space alone. The blood pH fell a mean of 0.11 +/- 0.03 and the PaCO2 rose a mean of 16.0 +/- 3.7 mm Hg when insufflation included the peritoneal cavity, whereas when insufflation was limited to the retroperitoneum, the pH fell a mean of 0.05 +/- 0.03 and the PaCO2 rose a mean of 7.5 +/- 2.8 mm Hg. Extrapleural thoracic dissection of gas was noted in one animal after insufflation limited to the retroperitoneal space. These findings confirm that there is significant absorption of CO2 from the peritoneal cavity during laparoscopy with CO2 insufflation, whether the pneumoperitoneum is primary or occurs secondary to retroperitoneal insufflation. If the insufflated gas is limited to the retroperitoneal space, however, the absorption of CO2 appears to be reduced in this animal model. The risk of thoracic dissection of gas may be greater during extraperitoneal insufflation than during intraperitoneal insufflation.

Absorption↗
PubMed1995

Radiation-induced decrease in nitric oxide synthase--containing nerves in the rat penis.

PURPOSE: Evaluate effect of prostatic irradiation on erectile function. MATERIALS AND METHODS: Forty-seven male adult rats were divided into three groups according to a single radiation dose to the prostate: control (no irradiation) (n = 15), 1,000 cGy (n = 15), and 2,000 cGy (n = 17). Five months after irradiation, rats underwent evaluation of penile vascularity and of erectile response to central and peripheral stimulation. After the study a proximal-shaft penile segment was obtained for staining. RESULTS: Histologic evaluation demonstrated that, with increasing radiation, the number of nitric oxide synthase-containing nerve fibers per penile segment decreased significantly: control, 225.6 +/- 9.7; 1,000 cGy, 156.3 +/- 12.0; 2,000 cGy, 85.8 +/- 10.1 (standard error of the mean). Maximal intracavernous pressure induced with electrostimulation decreased significantly with increasing radiation dose. After injection of papaverine, maximal intracavernous pressure was significantly decreased in only the 2,000-cGy group. CONCLUSION: A dose of 2,000 cGy over the prostatic bed induces erectile dysfunction by causing defects in the vascular supply of the erectile tissue and in the nerves and smooth muscle.

Amino Acid Oxidoreductases↗
PubMed1995

Regeneration of nitric oxide synthase-containing nerves after cavernous nerve neurotomy in the rat.

In patients who recover erectile function after radical prostatectomy (with preservation of at least 1 neurovascular bundle), a recovery time of 6 to 18 months is not uncommon. As this is also the usual time required for regeneration of spinal nerves, we believe that regeneration of cavernous nerves, partially damaged inadvertently, may be responsible. In a rat model, we examined the long-term effect of unilateral and bilateral cavernous nerve transection on the nonadrenergic/noncholinergic (NANC) nervous system and erectile function. In 31 rats, nitric oxide synthase (NOS), the enzyme that catalyzes nitric oxide production, was identified in penile nerve fibers from a mid-shaft segment with nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining and antibody to neuronal NOS. Animals were divided into three groups: 5 rats underwent pelvic exploration without transection of cavernous nerves (sham group); 13 rats underwent unilateral neurotomy of a 5-mm. segment of the cavernous nerve; and 13 rats underwent bilateral neurotomy. After bilateral ablation, the NOS-positive nerve fibers were significantly decreased at 3 weeks and remained so at 6 months; no erectile response could be elicited by pelvic nerve stimulation. After unilateral ablation, the NOS-positive nerve fibers were similarly decreased on the side of the neurotomy at 3 weeks, but by 6 months the number had increased significantly and approximated the level on the contralateral side. Furthermore, electrostimulation of the intact side induced a greater intracavernous pressure response at 6 months than at 3 weeks (N.B. the rat has an incomplete septum). Fibers positive for NOS were also identified in the dorsal nerve. The staining pattern diminished as rapidly and significantly on the side of neurotomy as in tissue from the corpus cavernosum. However, regeneration was not seen. To our knowledge, this is the first demonstration of regeneration of NOS-containing nerves after cavernous nerve neurotomy. Our findings support the reports by others that unilateral nerve-sparing is sufficient to preserve erectile function.

Amino Acid Oxidoreductases↗
PubMed1994

Randomised comparison of amoxycillin and erythromycin in treatment of genital chlamydial infection in pregnancy.

Erythromycin, the standard treatment for chlamydial infection in pregnant women, commonly causes side-effects, which limits its efficacy. In a randomised, double-blind study, we compared amoxycillin with erythromycin in this setting. 210 pregnant women with Chlamydia trachomatis infection were randomly assigned 7 days' treatment with amoxycillin (500 mg three times daily) or erythromycin (500 mg four times daily). Control cultures were obtained 21 days after treatment, during late pregnancy, and from the infant within a week of birth. Treatment was judged a failure if any post-treatment culture was positive or if the patient had to stop therapy because of severe side-effects. 11 women (5.2%) were lost to follow-up. 1 (of 100) amoxycillin-treated women had to stop treatment because of severe side-effects compared with 12 (of 99) erythromycin-treated women (p = 0.002). 1 woman in the amoxycillin group had a positive culture at the third-trimester examination. No positive post-treatment culture was found in the erythromycin group. Severe gastrointestinal side-effects were more common in women who received erythromycin (31 vs 6%, p < 0.001). The overall failure rate was therefore 2% in the amoxycillin group and 12% in the erythromycin group (p = 0.005). These results suggest that amoxycillin is an acceptable alternative to erythromycin for C trachomatis infection in pregnant women.

Adult↗
PubMed1994

Is colchicine effective in Peyronie's disease? A pilot study.

OBJECTIVES: The treatment of Peyronie's disease with oral or topical agents has not been entirely satisfactory. In this pilot study, we hypothesized that colchicine, known to induce collagenase activity and decrease collagen synthesis, might be an ideal agent in the treatment of Peyronie's disease. METHODS: Colchicine was administered orally for 3 to 5 months to a group of 24 previously untreated patients with Peyronie's disease. RESULTS: Peyronie's plaque decreased or disappeared in 12 of the 24 patients, 7 of 9 patients with painful erections reported significant relief, and penile curvature was improved in 7 of 19 cases. Erectile status, narrowing of the penis, and accompanying Dupuytren's contracture did not change in any of the cases. CONCLUSIONS: Although this pilot study shows some promising results of the use of colchicine in the treatment of Peyronie's disease, the ultimate usefulness of this agent will be determined only by a prospective double-blind clinical study.

Aged↗
PubMed1994

Gas embolism: helium is more lethal than carbon dioxide.

The search for alternatives to carbon dioxide (CO2) for insufflation during laparoscopy has included the consideration of helium. Helium is attractive because it is noncombustible and has no pharmacologic effects. Unfortunately, it is also relatively insoluble in blood, which potentially could exacerbate a venous gas embolism. We performed rapid intravenous injections of CO2 and helium into 4 dogs in amounts ranging from 5 to 10 ml of gas per kilogram body weight. Recovery after CO2 injection always occurred within 1 min. In 4 of 6 instances, the helium injection was fatal. Our results confirm that helium is more lethal than CO2 when injected intravenously. This implies that the use of helium for insufflation during laparoscopy might place patients at greater risk for adverse effects should venous gas embolism occur.

Animals↗
PubMed1994

The detailed neuroanatomy of the human striated urethral sphincter.

OBJECTIVE: To study the nerve supply of the striated urethral sphincter. MATERIALS AND METHODS: The pelvis from six formalin-fixed male cadavers was dissected. RESULTS: Cadaveric dissection revealed that both the intrinsic and extrinsic segments of the urethral rhabdosphincter receive their innervation from sacral roots S2-S4. The nerve fibres travel to their final destination via both the pudendal nerves and the nerve branches of the sacral roots. The terminal branches of the pudendal nerve enter the sphincteric area from the perineum. They separate shortly after they cross the ischial spine and run further ventromedially. Small branches approach the sphincter after their division from the dorsal nerve of the penis. The course of the pudendal nerve and its branching on the perineum are quite consistent. The pelvic branches travel inside the pelvis above the levator ani muscle. Among the cadavers the number of branches varied markedly, as did their site of termination (2.3 to 3.9 cm from the striated urethral sphincter). A substantial nerve approaching the sphincter from inside the pelvis was found. After it divided from the S2, S3 sacral roots it ran separately, initially just lateral to the fibres of the pelvic plexus and then on the dorsolateral surface of the rectum. In its terminal segment it dived into the levator ani muscle and terminated in the striated urethral sphincter. CONCLUSIONS: We believe that the nerve supply to the striated urethral sphincter consists of branches from both the pudendal nerve and the 'extrapudendal' nerves that run above the levator ani muscle inside the pelvis. The variations in the course of the latter are remarkable.

Humans↗
PubMed1994

Erectile dysfunction.

A better understanding of penile physiology and pathophysiology has revolutionized the diagnosis and treatment of erectile dysfunction in the past decade. This article summarizes the current knowledge and presents a patient's goal-directed approach to the evaluation and treatment of erectile dysfunction.

Erectile Dysfunction↗
PubMed1991

Long-term effects of biofeedback on migraine headache: a prospective follow-up study.

The aim of the present study was two-fold: to assess the long-term effects of biofeedback on migraine, and to determine the extent to which additional treatment after biofeedback treatment is completed can affect follow-up results. Ninety-six women whose migraine had been treated through biofeedback either 2-3 years (shorter follow-up) or 6-7 years (longer follow-up) earlier were divided into four groups according to how long ago they had received their biofeedback treatment and whether or not they had received any additional treatment (whatever the nature) since the posttreatment assessment: shorter follow-up without additional treatment (n = 24), shorter follow-up with additional treatment (n = 22), longer follow-up without additional treatment (n = 24), and longer follow-up with additional treatment (n = 26). Subjects were asked to keep a headache diary for five weeks, as they had done during earlier assessments. Overall, results showed that migraine activity was significantly less at follow-up than at pretreatment. However, whether the observed long-term benefits could be attributed to biofeedback was unclear because medication was found to be as much in use at follow-up as at pretreatment. Results also indicated that 51% of the subjects did seek additional treatment between posttreatment and follow-up. Contrary to expectations, however, additional treatment was not associated with better therapeutic benefits at follow-up. The research and the clinical implications of those findings are discussed.

Biofeedback, Psychology↗
PubMed1977

Complementation of adeno-associated satellite virus (AAV) by temperature-sensitive mutants of adenovirus type 31.

Temperature-sensitive (ts) matants of human adenovirus type 31 were able to complement adeno-associated satellite virus (AAV) antigen production in both HEK and KB cells at both permissive and non-permissive temperatures. However, mutant ts 94, an adenovirus 31 mutant which produces apparently normal amounts of structural protein and DNA but is defective in maturation, was significantly inhibited in its ability to potentiate AAV infectivity at the non-permissive temperature. Normal AAV DNA and adenovirus DNA were isolated from co-infections with AAV and mutant ts 94 at the non-permissive temperature. We suggest that an adenovirus-coded maturation function common to both adenovirus and AAV maturation is defective in the ts 94 system.

Adenoviruses, Human↗