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PubMed1980

An oestrone-releasing vaginal ring in the treatment of climacteric women.

Post-menopausal patients were treated with a new form of oestrogen administration by using two types of oestrone-containing vaginal rings. It was observed that oestrone was absorbed from the vagina as demonstrated by elevated plasma concentrations of oestrone (E1) and oestradiol (E2). In 3 out of 4 patients the ratio of E1/E2 was 4-5 in the first plasma samples collected after the initiation of the treatment. After the first week of treatment this ratio had dropped to 0.8-1.5, which indicates an increase and stabilization in the conversion of oestrone to oestradiol within 1 wk of treatment. The high levels of plasma oestrogens were associated with a decrease of plasma gonadotrophins and the disappearance of climacteric symptoms. The first type of ring tested resulted in a high initial burst of oestrone release, as evidenced by high concentrations of oestrone and oestradiol during the first 2 wk. In the second type of vaginal ring the high initial oestrone release was not present and the plasma oestrone and oestradiol levels were stable. The patients tolerated the treatment well, and after gaining experience, easily accepted this route of self-administration. It seems that the vaginal silastic ring is an effective steroid-delivery system in post-menopausal women. As judged by plasma oestrone and oestradiol profiles, it seems that the second type of ring was preferable to the first one as an intravaginal releasing device.

Aged↗

PubMed1989

Gastric banding in the treatment of morbid obesity.

Gastric banding was carried out in 30 patients as a treatment for morbid obesity. The mean excess weight lost at 3 months was 32.6 per cent (27 patients) and 69.7 per cent at 2 years (eight patients). Fifteen patients required 22 reoperations for technical complications. Two patients underwent removal of the band and seven patients were converted to a stapled vertical Silastic ring gastroplasty. Although gastric banding appears to be a satisfactory method of achieving weight loss, the complication and reoperation rates are unacceptable in our hands. It is recommended that this operation should no longer be used as a treatment for morbid obesity.

Adult↗

PubMed1989

Mechanisms that subserve estradiol's induction of increased prolactin concentrations: evidence of amplitude modulation of spontaneous prolactin secretory bursts.

Estradiol stimulates hyperprolactinemia in human beings and in experimental animals by mechanism(s) that remain largely undefined. We have tested the hypothesis that estrogen modulates episodic and rhythmic prolactin release. To this end we studied six postmenopausal women by repetitive venous sampling basally and on days 1, 5, 10, and 30 after intravaginal placement of an estradiol-impregnated polymeric silicone (Silastic) ring. Computerized analysis of episodic prolactin pulsatility revealed that estrogen amplified prolactin pulse amplitude threefold without changing prolactin pulse frequency. Fourier analysis disclosed heightened amplitudes of specific ultradian rhythms, and deconvolution analysis demonstrated a sevenfold increase in the mass of prolactin secreted per pulse with no change in its half-life. We conclude that estradiol selectively augments the amplitude of episodic prolactin pulsatility, amplifies ultradian rhythms, and increases the mass of prolactin released per secretory burst.

Activity Cycles↗

PubMed1991

Temporary external DDD pacing after cardiac operations.

Temporary atrial and ventricular pacing in the DVI, VVI, and AOO modes using atrioventricular sequential DVI devices is routinely used in cardiac operations. This study evaluated a new temporary external DDD pacemaker (Medtronic 5345 External Pulse Generator) capable of ten pacing modes. Thirty-nine devices have been applied to 38 adult patients (27 male, 11 female) after a variety of open heart procedures. Group 1 had atrial pacing wires placed 1.5 to 2.0 cm apart superiorly on the right atrium, group 2 had atrial wires placed 1.0 to 1.5 cm apart on the right atrial free wall, and group 3 had atrial wires placed on the right atrial free wall 0.8 cm apart, using a Silastic ring for fixation. Ventricular wires were placed on the free wall (group 1) or the diaphragmatic surface (groups 2 and 3) of the right ventricle. Postoperative atrial and ventricular sensing and pacing thresholds were obtained on return to the intensive care unit; analysis of variance demonstrated a significantly greater atrial sensing threshold in group 3. Four patients in group 1 permanently lost atrial sensing, 1 patient in group 2 intermittently lost atrial sensing at 24 hours with return at 36 hours postoperatively, and 1 patient in group 1 lost ventricular sensing capability. All other patients had adequate atrial and ventricular sensing capability documented until elective pacemaker removal (mean, 166 hours; range, 17 to 667.5 hours). Nineteen patients required some form of temporary pacing postoperatively; 11 patients demonstrated hemodynamic benefit from a pacing mode that is not available on the currently used DVI devices, and 7 of these required true DDD pacing capability. Six patients benefited from atrial pacing with adequate atrial sensing and simultaneous ventricular backup. Burst pacing with the device was used successfully to treat postoperative atrial flutter in 2 patients. We conclude that temporary external DDD pacing is feasible and effective in postoperative cardiac surgical patients. Atrial sensing is possible in most patients but electrode positioning is important for adequate thresholds. In some patients, hemodynamic as well as electrophysiologic improvement can be demonstrated with universal DDD pacing capability as compared with standard DVI pacing.

Adult↗

PubMed1983

Correction of congenital hydronephrosis in utero III. Early mid-trimester ureteral obstruction produces renal dysplasia.

Is the renal dysplasia (RD) commonly seen in babies with urinary tract obstruction a developmental consequence of the obstruction or is it an associated embryologic malformation? We produced complete unilateral ureteral obstruction in six 58- to 66-day old lamb fetuses by clipping a silastic ring on the ureter. Three fetuses survived to term. All obstructed kidneys were not only grossly hydronephrotic but dysplastic by histologic criteria; ie, parenchymal disorganization, primitive epithelial structures, and marked fibrosis. The contralateral unobstructed control kidneys were normal. The changes were similar to those seen in the human neonate with obstruction and RD, suggesting that in this model RD was caused by obstruction to the flow of urine early in fetal development.

Animals↗

PubMed1989

Etiology of intestinal damage in gastroschisis. I: Effects of amniotic fluid exposure and bowel constriction in a fetal lamb model.

Gastroschisis is often complicated by damage to the herniated small bowel, resulting in motility and absorption disturbances and occasional intestinal necrosis and atresia. To study the pathophysiology of this process, a model of gastroschisis was developed in fetal lambs. At 80 days' gestation, the anterior abdominal wall was partially excised to create a small peritoneal cavity, and the small bowel was extruded through a Silastic ring to create a defect of uniform size. In one experimental group, a tie was placed around the herniated bowel at the level of the abdominal wall to provide gradual constriction as the fetus grew. In a second group, no tie was placed. Control animals had a simple laparotomy and no abdominal wall defect; some also had a constrictor placed around the base of the bowel. The animals were delivered near term, and the bowel was evaluated histologically and by an in-vitro bowel motility assay. Histologic examination showed normal ganglion cells in all groups and no evidence of ischemic injury. A fibrous peel was seen only in bowel exposed to amniotic fluid, with or without a constrictor. Lymphatic and venous dilation, smooth-muscle thickening, and focal mucosal blunting were seen in bowel subjected to chronic obstruction by a constrictor, regardless of whether it was exposed to amniotic fluid. Both constriction of the bowel and amniotic fluid exposure were associated with a decrease in motility; these two effects were independent and additive.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗

PubMed2001

The insulin tolerance test in morbidly obese patients undergoing bariatric surgery.

OBJECTIVE: To assess the effect of massive weight loss in relation to insulin resistance and its correlation to changes in glycemic homeostasis and lipid profile in severely obese patients. RESEARCH METHODS AND PROCEDURES: A prospective clinical intervention study was carried out with 31 morbidly obese women (body mass index: 54.2 +/- 8.8 kg/m(2)) divided into three groups according to their glucose tolerance test: 14 normal, 8 impaired glucose tolerance, and 9 type 2 diabetes. All subjects underwent an insulin tolerance test with intravenous bolus of 0.1 U insulin/kg body weight before silastic ring vertical gastroplasty Roux-en-Y gastric bypass surgery, and again at 2, 4, 6, and 12 months postoperatively. Fasting plasma glucose, hemoglobin A1c, and lipid profile were also evaluated. RESULTS: A reduction of 68 +/- 15% in initial excess body weight was evident within 1 year. Along with weight loss, the following statistically significant changes were found: an increase in the insulin-sensitivity index (Kitt) and a decrease in fasting plasma glucose and hemoglobin A1c, most notably in the type 2 diabetes group. An overall improvement in lipid profile was observed in all three groups. DISCUSSION: Bariatric surgery was an effective therapeutic approach for these obese patients because it reduced both weight and insulin resistance, along with improving metabolic parameters. Significant correlations were found between insulin resistance and metabolic improvements. Weight loss after bariatric surgery induced an improvement in metabolic fitness, related to the reduction in insulin resistance over a range of glucose tolerance statuses from normal to diabetic.

Adult↗

PubMed2003

Insulin resistance in nondiabetic morbidly obese patients: effect of bariatric surgery.

OBJECTIVE: To evaluate insulin action on substrate use and insulinemia in nondiabetic class III obese patients before and after weight loss induced by bariatric surgery. RESEARCH METHODS AND PROCEDURES: Thirteen obese patients (four men/nine women; BMI = 56.3 +/- 2.7 kg/m2) and 13 lean subjects (five men/eight women; BMI = 22.4 +/- 0.5 kg/m2) underwent euglycemic clamp, oral glucose tolerance test, and indirect calorimetry. The study was carried out before (Study I) and after ( approximately 40% relative to initial body weight; Study II) weight loss induced by Roux-en-Y Gastric bypass with silastic ring surgery. RESULTS: The obese patients were insulin resistant (whole-body glucose use = 19.7 +/- 1.5 vs. 51.5 +/- 2.4 micromol/min per kilogram fat-free mass, p < 0.0001) and hyperinsulinemic in the fasting state (332 +/- 86 vs. 85 +/- 5 pM, p < 0.0001) and during the oral glucose tolerance test compared with the lean subjects. Fasting plasma insulin normalized after weight loss, whereas whole-body glucose use increased (35.5 +/- 3.7 micromol/min per kilogram fat-free mass, p < 0.05 vs. Study I). The higher insulin clearance of obese did not change during the follow-up period. Insulin-induced glucose oxidation and nonoxidative glucose disposal were lower in the obese compared with the lean group (all p < 0.05). In Study II, the former increased slightly, whereas nonoxidative glucose disposal reached values similar to those of the control group. Fasting lipid oxidation was higher in the obese than in the control group and did not change significantly in Study II. The insulin effect on lipid oxidation was slightly improved (p = 0.01 vs. Study I). DISCUSSION: The rapid weight loss after surgery in obese class III patients normalized insulinemia and improved insulin sensitivity almost entirely due to glucose storage, whereas fasting lipid oxidation remained high.

Adult↗

PubMed2001

Results of bariatric surgery.

OBJECTIVE: To present the results of bariatric surgery performed in our hospital over the last ten years. DESIGN: Longitudinal, clinical intervention with obesity surgery. SUBJECTS: To date in our hospital we have performed bariatric surgery on 496 patients. Ninety-seven percent of them received a restrictive method and 3% a combined procedure. The mean age of our patients was 39+/-9 y. The mean weight was 144+/-28 kg which corresponds to a mean BMI of 51+/-8 kg/m(2). The gender distribution is 18% male and 82% female patients. MEASUREMENTS: Success of surgery with early and late complications, no laboratory measurements. RESULTS: The early postoperative complications were the following: wound infection 3%, lethality 1.2%, pleural infusion 0.7% and evisceration 0.5%. The important late complications were pouch dilatation and stomastenosis in 18% and staple line disruption in 11%. Slippage of the adjustable silicone gastric banding (ASGB) amounted to 5% and hernias emerged in 7% of patients. A migration and band infection occurred in 0.7%. Reoperations were necessary in 10% of the silastic ring vertical gastroplasty (SRVG) and in 39% of the ASGB patients. Patients were followed up every two months in the first year and later, annually. Blood samples were taken after 25%, 50%, 75% and 100% loss of excess weight. To date, 91% of our patients have reached an excess weight loss of 25%. 71% lost half of their overweight and one third (32%) were able to reduce it by 75%. 8% of our patients attained normal weight. CONCLUSIONS: For long term compliance and to avoid regain of weight, a close follow-up is necessary. We therefore offer special care which, in addition to the postoperative surgical care, includes visits by dieticians, internists, psychologists as well as exercise therapy. Knowledge of morbid obesity and skill in bariatric surgery are prior conditions to avoid complications and for success in bariatric surgery.

Adult↗

PubMed1998

Effect of colonic obstruction on the distribution of matrix metalloproteinases during anastomotic healing.

BACKGROUND: Anastomotic dehiscence is common after surgery for colonic obstruction. The strength of an anastomosis is dependent on collagen, which is degraded by matrix metalloproteinases (MMPs). The aim of this study was to determine the distribution of the MMPs and their inhibitor, tissue inhibitor of metalloproteinases (TIMP) 1 in an experimental model of colonic obstruction, with and without resection and anastomosis. METHODS: The distal colon of rabbits was obstructed with a Silastic ring for 24 h and then either the ring was removed or the obstructed segment was resected and an anastomosis formed. Rabbits were killed immediately or at intervals for up to 7 days after operation. The distribution of the MMPs and TIMP-1 was examined by indirect immunofluorescence. RESULTS: MMPs and TIMP-1 were present throughout the descending colon for 24 h in both groups. They persisted to the third day in rabbits with an anastomosis but by day 7 were restricted to the suture line. Their presence correlated with microscopic damage. CONCLUSION: The extensive distribution of the MMPs suggests that these enzymes contribute to anastomotic dehiscence, but only in the immediate postoperative period.

Anastomosis, Surgical↗

PubMed2005

Inhibin B in men with severe obesity and after weight reduction following gastroplasty.

Although the effect of obesity on some gonadal functions in men is known, its effect on Sertoli cell function has not been reported. We tested the hypothesis that the serum inhibin B level is decreased in men with severe obesity, and that this change persists after significant weight loss. We measured gonadal hormones in 17 obese men before (baseline) and after weight reduction following silastic ring vertical gastroplasty (SRVG). Their baseline body mass index (BMI) was 44.3 +/- 1.7 kg/ m2, mean +/- standard error of the mean (SEM). Seven of 16 obese men (44%), compared to 8 of 69 reference men (12%), had a baseline inhibin B level below 100 pg/ml (p < 0.01). A weak inverse association was found between inhibin B and BMI before weight reduction (r = -0.494, p = 0.072). Furthermore, FSH levels, which were weakly inversely associated with inhibin B levels (r = -0.482, p = 0.059), were inappropriately unelevated in 5 of the 7 obese men with low (below 100 pg/ml) inhibin B. After a weight reduction of 40 +/- 2.6 kg, mean +/- SEM, following surgery, the obese men's BMI was 31.6 +/- 1.5 kg/m2, mean +/- SEM, and inhibin B normalized in 3 of the 7 patients with low inhibin B. Despite weight reduction, FSH remained inappropriately unelevated in 2 of the 4 patients whose inhibin B remained low. This study also confirmed previously published findings that obese men have low serum total and free testosterone and relative hypogonadotropic (low LH) hypogonadism that may persist after weight reduction. In conclusion, Serum inhibin B levels in obese men may be low. This may be due to relative hypogonadotropic (also low FSH) hypogonadism.

Adolescent↗

PubMed1994

The benefits of using the loop ligature (Endoloop) laparoscopic sterilization procedure in a residency program.

This study was conducted to determine the impact of the addition of the loop ligation (Endoloop) technique on choice of sterilization surgery in our residency teaching program and to investigate significant differences between this technique and other methods performed at our hospital. A retrospective study of all patients undergoing interval tubal sterilization at Tampa General Hospital in 1989 and 1991 was undertaken. Data were analyzed to determine the frequency of sterilization methods and differences between the loop ligation method and the other procedures performed; p values of less than 0.05 were considered significant. Sixty-one patients in 1989 and 75 in 1991 qualified for the study. Five methods of interval sterilization were performed: loop ligation, minilaparotomy, colpotomy, laparoscopic bipolar fulguration, and Silastic ring application. The frequency of the loop ligature technique increased from 0% in 1989 to 40% in 1991. There were no significant differences in operative time and complication rate among the loop method and other procedures. The loop ligature (Endoloop) method of laparoscopic sterilization does not significantly change the length of surgery, blood loss, or complication rate compared to the other laparoscopic techniques used in our residency program. This method provides a definitive tissue diagnosis, eliminates the risk of thermal injury, theoretically provides an opportunity of later tubal reanastomosis, and subjectively helps develop laparoscopic skills.

Female↗

PubMed1992

Gastric restriction procedures for treating severe obesity.

Gastric restriction procedures are operations to decrease gastric volume. They are the most common, simple, and safe operations for the treatment of severe obesity. The original horizontal gastroplasties were unsuccessful but modern operations such as vertical banded gastroplasty, silastic ring gastroplasty, and gastric banding produce good weight loss with improvement in health. Although late weight gain does occur, satisfactory 5-y results are available and are presented. Patient selection, complications, mechanism of action, and future studies are also discussed. Long-term data with complete patient follow-up and randomized trials comparing modern operations with nonoperative treatment are still needed.

Gastroplasty↗

PubMed1993

Steroidal regulation of biologically active luteinizing hormone secretion in men and women.

The biological activity of circulating luteinizing hormone (LH) molecules can be assessed with high sensitivity, specificity, and precision by the in-vitro rat interstitial (Leydig)-cell testosterone (RICT) bioassay. Compared to immunoreactive estimates of the LH content of plasma, the living Leydig-cell bioassay integrates the functional in-vitro potency of all circulating LH isoforms, while simultaneously reflecting the effects of otherwise potentially confounding in-vivo antagonists of LH action on steroidogenesis. Here, we review the pathophysiological regulation by steroid hormones of bioactive LH secretion and clearance in men and women. Our investigations and those in the available literature indicate that: (i) exogenous (non-aromatizable) 5-alpha-dihydrotestosterone infusion suppresses LH bioactivity, whereas blockade of the endogenous androgen receptor with flutamide increases secretion of biopotent LH in men; (ii) endogenous androgen excess due to a masculinizing testosterone-secreting adrenal tumour in a post-menopausal woman reversibly suppressed plasma LH bioactivity markedly; (iii) exogenous oestradiol infusion will reduce whereas the antioestrogen, tamoxifen-HCl, can increase bioactive LH secretion in young men; (iv) the effect of anti-oestrogen is blunted in healthy older men; (v) endogenous hyperoestrogenism due to an adrenal oestrogen-secreting tumour in a middle-aged man with gynaecomastia profoundly but reversibly inhibited bioactive LH secretion; (vi) in post-menopausal women, exogenous oestrogen administration, whether oral (diethylstilbestrol), percutaneous (oestradiol), or intravaginal (oestradiol-impregnated silastic ring), exerts a temporally biphasic effect on basal bioactive LH secretion, i.e. acute suppression (within 24 h), subacute escape (at 5-10 days), and longer-term inhibition (30 days); (vii) during the normal menstrual cycle, bioactive LH secretion is pulsatile and both frequency and amplitude regulated; and (viii) oestrogen exposure can enhance gonadotrophin releasing hormone (GnRH)'s stimulatory action on biologically active LH secretion, resulting in so-called GnRH self-priming. Oestrogen's facilitative effects are achieved by a novel mechanism, in which oestrogen augments LH secretory burst mass and duration. Moreover, GnRH dose-LH secretory response studies show that oestrogen promotes an increase in GnRH efficacy (maximal effects) but not GnRH sensitivity (potency or half-maximally effective doses of GnRH). We conclude that steroid hormones are primary regulators of physiologically pulsatile bioactive LH secretion in healthy men and women. Moreover, steroids exert potent pathological effects on biologically active LH release in conditions of selective hyperandrogenism or hyperoestrogenism due to steroid-secreting adrenal or gonadal tumours.

Androgens↗

PubMed1992

A new device for pupillary dilatation in vitreous surgery.

A completely new surgical technique to obtain pupillary dilatation is presented. It permits achievement of a mydriasis sufficient to observe the vitreous cavity in both phakic and aphakic eyes during vitreous surgery. Miotic immobile pupils not dilatable pharmacologically are enlarged by means of a silastic ring with a C-shaped groove on its outer part. This is introduced into the eye through a limbic opening. When in place, the external sulcus of the ring hosts the pupillary rim. Twelve patients (three phakic and nine aphakic) were treated. In two patients operated upon previously with silicone oil tamponade, some difficulties were encountered during the insertion of the device owing to the lubricating effect of the oil. After the removal of the ring, all the pupils returned to a round shape, with no apparent damage to the iris structure.

Aphakia, Postcataract↗

PubMed1987

Bariatric surgery should be more widely accepted.

Bariatric surgery is not widely accepted by the general medical profession because of several misconceptions. Many physicians believe that morbidly obese persons could lose weight if they used their willpower, that bariatric surgery is a major operation in a high-risk population, and that weight loss is unpredictable, follow-up is poor, the reoperation rate is high, and late weight gain is common. Using the results of our series of 500 vertical Silastic ring gastroplasties and a collected series of 3,237 cases, we respond to these objections. Nonsurgical methods of weight loss are successful in less than 5% of morbidly obese patients. The operative mortality in the collected cases was 0.2%. The average percentage of excess weight lost is 66%, with only 10% of patients failing to lose at least 40% of their excess weight. With diligence, a follow-up of more than 90% can be obtained. The reoperation rate among experienced surgeons averages 1% to 2% per year. Mild late weight gain occurs in about 15% of cases, but significant weight gain occurs in less than 5% of patients. We believe that vertical staple gastroplasty is safe and effective and that it should be accepted as such by the medical profession.

Adult↗

PubMedDate not supplied

Effects of estradiol with oral or intravaginal progesterone on risk markers for breast cancer in a postmenopausal monkey model.

OBJECTIVE: To evaluate the effects of oral estradiol given with either oral or intravaginal micronized progesterone (P4) on risk biomarkers for breast cancer in a postmenopausal monkey model. DESIGN: This experiment was a two-way crossover study in which 20 ovariectomized adult female cynomolgus macaques were treated (in equivalent doses for women) with oral estradiol (1 mg/d) + oral micronized P4 (200 mg/d) or intravaginal P4 delivered by Silastic rings (6- to 10-mg/d release rate). Hormone treatments lasted 2 months and were separated by a 1-month washout period. The primary outcome measure was breast epithelial proliferation. RESULTS: Serum P4 concentrations were significantly greater in subjects receiving oral P4 (10.9 ng/mL) compared with intravaginal P4 (3.8 ng/mL) at 2 to 3 hours after oral dosing (P<0.0001) but not at 24 to 28 hours after oral dosing (2.9 ng/mL for oral P4 vs 3.2 ng/mL for intravaginal P4 at 2 months, P=0.19). Serum estradiol concentrations were significantly lower after oral P4 than after intravaginal P4 (P<0.05 for all time points). Oral P4 resulted in significantly decreased body weight (-2.5%) compared with intravaginal P4 (+3.6%) (P=0.0001). Markers of breast proliferation, sex steroid receptor expression, and endometrial area did not differ significantly between oral P4 and intravaginal P4 treatments (P>0.1 for all). CONCLUSIONS: Despite different pharmacodynamic profiles, oral and intravaginal P4 had similar effects on biomarkers in the postmenopausal breast.

Administration, Intravaginal↗

PubMed1978

Laparoscopic tubal occlusion with silicone rubber bands.

Application of the silastic ring to the Fallopian tubes through the laparoscope seems to be a simple, safe and acceptable method of tubal sterilization. The technique and results in 337 patients are described. In the majority of cases, the procedure was effected in the outpatient department under local anaesthesia. Transsection of the tube (with or without bleeding), tearing of the mesosalpinx, and avulsion of the tube at the uterotubal junction were the most common complications; with experience and adherence to the proper technique of ring application, the above can be minimized. The pregnancy rate following this procedure seems to be acceptable, but long-term follow-up is necessary for definitive conclusions.

Adolescent↗