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Biomedical subjects

R E Leach

Publications and source records attributed to R E Leach.

At least 37 records · Page 2Linked to original sources

Orthopedics and sports medicine.

There are potential long-term problems with anterior cruciate ligament reconstruction, even in those who have had a successful result. Arthroplasty of the elbow has been evolving. Infection after total joint arthroplasty is a potentially disastrous complication.

Orthopedics↗

Blastocyst cavitation is accelerated by ethanol- or ionophore-induced elevation of intracellular calcium.

To extend our previous finding that ethanol stimulates murine preimplantation development, we focused in the current study on the cavitation and expansion of the blastocyst. Ethanol stimulation of blastocyst cavitation and expansion was optimal at a concentration of 0.1% and required only a 5-min exposure. Because intracellular levels of calcium were transiently increased in the ethanol-exposed embryos, we determined the effect of directly increasing calcium on the rates of blastocyst cavitation and expansion. Treatment with the calcium ionophore, A23187, altered development much as did ethanol, indicating that ethanol may stimulate preimplantation development by increasing the intracellular calcium concentration. The relationship between intracellular calcium levels and blastocoel volume suggests that morphogenetic events during preimplantation development, particularly cavitation and blastocyst formation, may be regulated through modulation of intracellular calcium levels.

Aniline Compounds↗

Mouse blastocyst outgrowth and implantation rates following exposure to ethanol or A23187 during culture in vitro.

This study focused on the effects of ethanol on blastocyst outgrowth and implantation in mice. Blastocysts were exposed to ethanol in Ham's F10 medium and then cultured free of ethanol on fibronectin-coated Petri dishes to assess trophoblast cell adhesion and migration. The time necessary for half of the embryos to outgrow was significantly less (P < 0.05) following treatment with 0.1%, 0.2%, 0.4% or 1.0% (w/v) ethanol for either 5 min or 24 h compared with controls. The rate of trophoblast cell migration was determined by measuring the mean area of outgrowing embryos using an image analysis system. Blastocysts exposed to ethanol for 5 min produced a greater (P < 0.05) average outgrowth area than did stage-matched controls. Acceleration of blastocyst cavitation by ethanol is known to be associated with an increase in the intracellular concentration of calcium. Here, treatment with the calcium ionophore A23187 stimulated (P < 0.05) trophoblast outgrowth and accelerated (P < 0.05) the rate of cell migration. In an attempt to correlate the effect of ethanol on outgrowth in vitro with implantation in utero, cultured blastocysts were either not exposed to ethanol or exposed to 0.1% ethanol for 5 min and transferred 24 h later to the uteri of pseudopregnant dams. The implantation rate (39.4%, n = 376) and the rate of development to term (2.45 pups per mouse, n = 20) were higher (P < 0.05) in mice receiving ethanol-treated embryos compared with those receiving control embryos (20.8%, n = 331; 1.16 pups per mouse, n = 18, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Development of in vitro fertilized mouse embryos exposed to ethanol during the preimplantation period: accelerated embryogenesis at subtoxic levels.

This study examined the effects of ethanol (EtOH) on mouse preimplantation development using an in vitro culture method. Embryos at the 1-cell, 2-cell, or 4-cell stage were exposed for 24 h to medium containing EtOH, then further cultured without EtOH to determine their ability to form blastocysts and to eventually hatch from the zona pellucida. EtOH exposure either arrested or enhanced normal development, depending on dose and embryonic stage of exposure. Exposure of 1-cell and 2-cell embryos to 1.6% (w/v) EtOH decreased blastocyst formation and hatching, and exposure of 1-cell embryos to 0.4% EtOH inhibited their development. At 0.1%, EtOH had an opposite effect, causing an increase in the percent blastocyst formation of treated 1-cell and 2-cell embryos. Neither inhibition nor stimulation of blastocyst formation occurred in 4-cell embryos exposed to 0.1-1.6% EtOH. Using an in vitro outgrowth model of implantation, embryos that reached the blastocyst stage were further tested for their ability to produce differentiated trophoblast cells. Blastocysts previously exposed to 0.1% EtOH during the 1-cell stage appeared to form adhesive trophoblasts earlier than control embryos, indicating that EtOH exposure can induce precocious differentiation of the trophoblast cells. The EtOH treated blastocysts contained significantly more cells than control blastocysts. These results indicate that EtOH can alter preimplantation development by either inhibiting or accelerating cell growth and differentiation.

Animals↗

The team player.

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Health Care Reform↗

A comparative evaluation of Poloxamer 407 and oxidized regenerated cellulose (Interceed [TC7]) to reduce postoperative adhesion formation in the rat uterine horn model.

OBJECTIVES: To determine if Poloxamer 407 (poloxamer, Pluronic F-127; BASF Wyandotte Corp., Parsippany, NJ) is as effective as Interceed(TC7) (Ethicon, a Johnson and Johnson company, Sommerville, NJ) in preventing postoperative adhesion formation using the rat uterine horn model and to determine if the presence of blood or lactated Ringer's solution affects the effectiveness of Poloxamer 407. DESIGN, SETTING, PARTICIPANTS: Sprague-Dawley white rats, weighing 225 to 250 g in a conventional laboratory setting. The left or right sidewall was randomly assigned to receive no treatment (control), Interceed(TC7), or poloxamer. INTERVENTIONS: Each uterine horn and ipsilateral sidewall was subjected to a standardized lesion of denudation. To evaluate the barrier agents in the presence of blood, a sidewall vessel was ligated and a thrombus allowed to form. To evaluate the effectiveness of lactated Ringer's solution, 10 mL was injected intraperitoneally after abdominal closure. MAIN OUTCOME MEASURES: Degree of adhesion formation was evaluated 14 days after surgery. RESULTS: The adhesion score for the poloxamer-treated animals was significantly lower than its control. Interceed(TC7) did not reduce adhesion formation as compared with its control. In animals that received both poloxamer and Interceed(TC7) on either side, the poloxamer-treated sides had a significantly lower adhesion score than Interceed(TC7)-treated sides. The presence of blood and lactated Ringer's reduced the adhesion-reducing properties of poloxamer. CONCLUSION: In this model, poloxamer is more effective than Interceed(TC7) in the prevention of postoperative adhesion formation. These findings also suggest that the presence of blood compromises the effectiveness of poloxamer to prevent postoperative adhesion formation, therefore requiring complete hemostasis before poloxamer's application. Lactated Ringer's instillation was ineffective in reducing adhesion formation on the control or poloxamer-treated sidewall.

Animals↗

Selective embryo reduction of an interstitial heterotopic gestation.

A case of combined interstitial and intrauterine pregnancy is described. The sonographic finding of a thick myometrial bridge separating a twin pregnancy may be unique to heterotopic cornual pregnancies and is illustrated. The method of selective embryo reduction with potassium chloride to terminate the interstitial pregnancy without damage to the intrauterine pregnancy is also described. The intrauterine pregnancy continued successfully to term.

Adult↗

Long-term results of surgical management of Achilles tendinitis in runners.

Achilles tendinitis is a common occurrence in long-distance runners. Although most respond well to conservative therapy, there are some who require operative intervention. The short-term results of surgical treatment are good, with a success rate more than 85%. The authors present nine successful long-term results in runners. However, in two of the runners who continued to compete and train at long distances, symptoms recurred. Reoperations were performed to permit successful running careers for five and nine years. Runners resumed their careers after the second operation by supervised training and long-distance, competitive activities.

Achilles Tendon↗

The senior tennis player.

Mature athletes playing tennis can sustain both acute and chronic injuries. A number of the injuries are related to a gradual loss of flexibility and strength. Much of this is reversible with properly directed conditioning and rehabilitative programs.

Aged↗

Plantar fasciitis. Etiology, treatment, surgical results, and review of the literature.

Plantar fasciitis is a common orthopedic syndrome among athletes and nonathletes. The etiology of the pain is multifactorial but usually involves inflammation and degeneration of the plantar fascia origin. The majority of patients will respond to conservative measures. Surgical treatment is reserved for those patients who do not respond. A complete plantar fascia release is performed through a medial longitudinal incision. Prominent heel spurs and degenerated areas in the plantar fascia are resected. Of 27 surgically treated cases followed from one to three years, satisfactory results were obtained in 24 cases. Histologically, localized fibrosis or granulomatous changes or both were noted in several cases.

Adolescent↗

Reduction of postoperative adhesions in the rat uterine horn model with poloxamer 407.

Adjuvants shown to have significant adhesion prevention capabilities have been based on barrier separation of deperitonealized surfaces. We investigated the adhesion prevention properties of poloxamer 407. This polyol, in the proper concentration, is fluid at room temperature and becomes a firm gel at body temperature. The prevention of postoperative adhesions was evaluated in the rat uterine horn model. Twenty-two rats underwent bilateral surgical injury to the uterine horn and the parietal peritoneum. A random side was treated with a 30% solution of poloxamer 407. Twenty-one days later the animals were sacrificed and evaluated for the presence of adhesions. A highly significant reduction in adhesion formation was documented on the treated side.

Animals↗

Management of ectopic pregnancy.

Risk factors for ectopic pregnancy include previous ectopic pregnancy, current intrauterine device use, prior fallopian tube surgery, previous pelvic inflammatory disease and a prior history of infertility. Abdominal pain is the most common symptom, followed by amenorrhea or vaginal bleeding, nausea, vomiting, syncope and dizziness. Referred shoulder pain following the onset of abdominal pain is characteristic of intraperitoneal bleeding and, in the appropriate clinical setting, strongly suggests a ruptured ectopic pregnancy. A coordinated evaluation includes measurement of serum human chorionic gonadotropin concentration and transabdominal or, preferably, transvaginal ultrasonography. Treatment is primarily by one of a variety of surgical techniques. Medical therapy with methotrexate or other drugs is currently under investigation.

Chorionic Gonadotropin↗

The role of closed reduction in tibial shaft fractures.

Although several methods of treating difficult tibial shaft fractures have been introduced in the past few decades, closed reduction remains the cornerstone of treatment. The physician must be able to recognize those tibial fractures suitable for treatment by this method, as opposed to fractures that have the potential to cause problems and would be better handled initially by other means. Properly performed, closed reduction in conjunction with early weight bearing accomplishes the goals of solid bony union, normal function, and a cosmetically acceptable appearance. This nonoperative approach avoids the potential morbidity associated with surgery and has been shown to give excellent results in the hands of a number of different physicians.

Casts, Surgical↗

Modern management of ectopic pregnancy.

The modern management of ectopic pregnancy has been influenced greatly by recent advances in human chorionic gonadotropin determination and ultrasound. Serum progesterone determination holds promise as a means of identifying abnormal gestations. Early diagnosis of tubal pregnancies has prompted conservative surgical treatment and the use of medical therapy in selected cases. Because of the improvement in diagnostic aids and conservative treatment, we are documenting a change in epidemiologic profiles. The incidence of ectopic pregnancy has increased, with a concomitant decrease in mortality. Fertility after conservative surgical procedures appears improved over that with radical treatment. However, women with ectopic pregnancies continue to have reduced fertility potential.

Chorionic Gonadotropin↗

Reconstruction of malunited fractures of the lateral malleolus.

The cases of twenty-six patients who had a reconstructive surgical procedure for treatment of a malunion of a displaced fracture of the fibula were evaluated. In these patients, who had pain, swelling of the ankle, and stiffness at an average of six years after the injury, the malunions were classified radiographically as either occult (eighteen patients) or overt (eight patients). An occult malunion was one in which the talus remained in its normal position, but the lateral malleolus showed residual displacement, characterized by external rotation and shortening. In an overt malunion, there were similar changes in the lateral malleolus, but the talus was displaced. All of the patients were treated by osteotomy of the lateral malleolus to correct the external rotation and shortening, to reduce the lateral subluxation of the anterior aspect of the tibiofibular joint, and to restore the stability of the talus. At an average follow-up of seven years (range, six months to eleven years), twenty of the twenty-six patients were able to resume the preinjury level of activity; three had improvement in the ability to walk and in the level of functional activity, although they still had intermittent pain; and three had not benefited from the procedure.

Adolescent↗

Sportsmedicine.

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Humans↗