SEARCH · PubMed Health

Results for “Random Allocation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources

PubMed1984

Functional cast-bracing for Colles' fractures. A comparison between cast-bracing and conventional plaster casts.

The use of Orthoplast cast-bracing to allow early hand function in the treatment of displaced Colles' fractures was investigated in 243 patients. They were randomly allocated into three groups: in the first a conventional Colles' type plaster was used; in the second an above-elbow cast-brace with the forearm in supination; and in the third a below-elbow cast-brace. Radiographic measurements were made at each stage of treatment, and the final anatomical result was scored using Sarmiento's (1975) criteria. Function was assessed at three months and at six months. The anatomical result was not influenced by the method of immobilisation but was related to the efficacy of reduction. Loss of position in the braces was no greater than in plaster. The functional result at three months also was uninfluenced by the method of immobilisation; it was, however, related to the severity of the initial displacement, and (to a lesser degree) to the anatomical result, an effect which was lost at six months. Early hand function and the supinated position advocated by Sarmiento were found to confer no anatomical or functional advantage; we could see no reason to change from the use of conventional plaster casts in the treatment of uncomplicated Colles' fractures.

Adolescent↗

PubMed2002

Effects of controlled mechanical ventilation on respiratory muscle contractile properties in rabbits.

OBJECTIVE: We examined in rabbits the effects of more than 48 h of mechanical ventilation on the contractile properties and fiber type adaptations of the respiratory muscles. DESIGN AND SETTING: Experimental prospective study in a university laboratory. ANIMALS AND INTERVENTIONS: Nineteen rabbits were randomly allocated to two groups: control (n=10) or mechanically ventilated (MV; n=9) for 51+/-3 h. MEASUREMENTS AND RESULTS: Respiratory muscles contractile properties were analyzed before and after a fatigue protocol using in vivo isometric 1-s tetanic contraction characteristics in both muscles: peak tetanic force, contraction time, relaxation time, and total contraction time. Both muscle fiber type proportions, diameter, and cross-sectional areas were measured using ATPase staining. The MV rabbits showed significant weight loss in both muscles, accompanied by a reduced peak tetanic force (9.96+/-3.2 vs. 7.44+/-2.2 N for diaphragm of control and MV animals respectively), fatigue resistance index, and increased relaxation time (57.5+/-8.7 vs. 85.8+/-9.4 ms for diaphragm of control and MV animals) and contraction time. These impairments in the MV group worsened after the fatigue runs. Both muscle showed a significant atrophy of type IIa and IIb fibers but a stability in type I fibers cross-sectional area. CONCLUSIONS: Mechanical ventilation in rabbits produces alterations in contractile properties of the diaphragm and 5th external intercostal muscle, increases both muscles fatigue, and promotes atrophy of type II fibers.

Animals↗

PubMed2001

Effect of replacing cotton seed cake with poultry droppings on weight gain of growing cattle at Bambui, Cameroon.

To investigate the effect of replacing cotton seed cake by poultry droppings in the diet of cattle, 30 animals were randomly allocated to three dietary treatments in a 2 x 3 factorial design, sex x treatments. The three treatments consisted of replacing 0%, 25% and 50% (T0, T25, T50 respectively) of the crude protein in 500 g of cotton seed cake with an equivalent amount of protein in poultry droppings. The concentrate offered was 615 g in T0, 652.5 g in T25 and 690 g in T50 per animal per day. After an adaptation period of 14 days, followed by 65 days of the experiment, the intake of concentrate and the average daily weight gains were recorded. There was no significant difference (p > 0.05) in the concentrate intake or average daily weight gain of bulls subjected to the three treatments. However, heifers tended to grow more slowly on T50 compared to T0 (p < 0.05), though the difference in their intake of concentrate was not significant (p > 0.05). Although T50 (47% inclusion in total concentrate), was less palatable, it seemed to have increased forage intake from pasture. These results suggest that poultry droppings can effectively substitute cotton seed cake in the diets of suckler cattle.

Animal Feed↗

PubMed2001

Fetal exencephaly arising as a result of preimplantation exposure to ammonium chloride.

OBJECTIVES: To investigate the effect of preimplantation exposure to 0.6 mM ammonium chloride on both preimplantation and postimplantation development of (F1 x F1) strain mouse embryos. METHOD: Two-cell stage mouse embryos were randomly allocated to culture in either M16 medium or M16 added with 0.6 mM ammonium chloride for 2 days before being transferred to 2.5 day pseudopregnant recipients. Embryo morphology was assessed after 1 and 2 days of culture. The recipient females were sacrificed on day 15.5 of gestation. The number of implantation sites, fetuses, moles and any gross abnormalities found were noted. RESULTS: There was no significant difference in the number of embryos reaching morula stage after two days of culture between the two groups (chi2=0.86, P>0.05). Implantation and pregnancy loss rates between the two groups were within comparable ranges. Crown-rump length was significantly higher in the group of embryos exposed to ammonium chloride (t=2.46, P<0.05). There was one gross abnormality, exencephaly, detected in the experimental group (4.35% per fetus obtained). CONCLUSIONS: Besides the abnormal increase in fetal size, preimplantation exposure to ammonium chloride also resulted in gross abnormality, exencephaly. If such effects occurred in the course of human in vitro fertilization, it could be devastating. Further study in this aspect is, therefore, clinically very important in preventing unwanted abnormalities that could arise from human in vitro fertilization.

Ammonium Chloride↗

PubMed1999

Intragraft CD45 RO gene expression is an early marker to detect small bowel allograft rejection in rats.

Wistar Furth (WF) intestinal allografts were transplanted into Sprague-Dawley (SD) rats. Recipients were randomly allocated into the following groups: (1) no treatment; (2) cyclosporine (CsA) 6 mg/kg/day, daily, subcutaneously (s.c.; full-dose therapy); (3) CsA 3 mg/kg/day, daily, s.c. (half-dose therapy); and (4) CsA 3 mg/kg/day, daily, s.c. + Tripterygium Wilfordii Hook. WF (TW) 3 mg/kg/day, daily, s.c. WF rats with intestinal autografts were used as controls. CD45RO intragraft expression and its index (CD45RO/CD45), measured by reverse transcription polymerase chain reaction (RT-PCR), were significantly elevated in untreated and half-dose CsA-treated allografts as early as postoperative day (POD) 4, when rejection of intestinal allografts was not detected by routine pathology. Intestinal permeability measured by Tc-DTPA radioassay was significantly elevated in untreated allografts on POD 6. Histology showed that there was severe rejection in untreated intestinal allografts and mild rejection in allografts treated with a half dose of CsA on POD 6. There was a normal CD45RO expression, permeability, and histology in intestinal allografts treated with either a full dose of CsA or a half dose of CsA + TW. These data indicate that CD45RO intragraft gene expression is an early marker to detect intestinal allograft rejection in rats.

Animals↗

PubMed2001

Cytologic and biochemical changes associated with inoculation of amniotic fluid and meconium into lungs of neonatal rats.

OBJECTIVE: To evaluate the effect of homologous amniotic fluid and meconium inoculated intratracheally into the lungs of neonatal rats. ANIMALS: 153 male 7-day-old Fischer-344 rats. PROCEDURE: Amniotic fluid was obtained by cesarean section from the uterus of pregnant rats and meconium was collected at the time of birth from the gastrointestinal tract of neonatal rats. Neonatal rats were randomly allocated into 5 treatment groups. Two groups received 0.05 ml of saline (0.9% NaCl) solution; the third and fourth groups received 0.05 ml of 50% or 100% amniotic fluid, respectively; the fifth group was inoculated with 0.05 ml of a 20% suspension of meconium. Six or 7 rat pups/group were euthanatized by exsanguination under halothane anesthesia at postinoculation days 1, 3, 7, and 14. The magnitude of injury and inflammatory response was determined by biochemical and cytologic analyses of bronchoalveolar lavage fluid. RESULTS: Inoculation with saline solution and amniotic fluid did not induce pulmonary injury or inflammatory response. Inoculation with meconium induced significant (P < 0.01) injury and inflammatory response, characterized by the release of cytosolic enzymes and recruitment of neutrophils in the lung. CONCLUSIONS: Saline solution is an innocuous vehicle that can be safely used in intratracheal inoculations in neonatal rats. Homologous amniotic fluid, despite containing keratin and epidermal cells, does not cause acute injury or inflammation in the lung. In contrast, meconium acts as a toxic substance injuring respiratory cells and causing a vigorous but transient leukocytic inflammatory reaction in the lungs.

Alkaline Phosphatase↗

PubMed2004

Early-weaned sows: altrenogest therapy, estrus, ovulation, and reproductive performance.

Early weaning is a technique used to increase swine health status, and may cause consequences in reproductive performance of sows. An experiment was performed to evaluate these effects in a herd of sows, with weaning at 9 or 10 days post-farrowing, located in west of Minas Gerais, Brazil. Large-White sows (n=102), with three or four previous parturitions were randomly allocated to three treatment groups: T1: artificial insemination (AI) at first post-weaning estrus of the sows; T2: AI at second post-weaning estrus, T3: AI at first estrus, after an administration of a daily individual dose of 20 mg of altrenogest from 5 to 8 days post-weaning. The duration of the first post-weaning estrus did not differ among treatment groups; however, the second estrus of the T2 group was of shorter duration relative to the other treatment groups (P< or =0.035). Ovulation occurred earlier at the second estrus of the T2 group, compared with the T1 and T3 groups (P< or =0.027), being similar to that at the first estrus of T2 group (P=0.177). The relationship of the timing between ovulation and estrus was similar among treatment groups (P> or =0.221). There was no difference in farrowing rate among treatment groups (P> or =0.313). The T2 group produced a mean of 2.5 more piglets per litter (P=0.002). In conclusion, the use of altrenogest did not increase the reproductive performance of early-weaned sows.

Animals↗

PubMed2004

Lambing rates and litter sizes following intrauterine or cervical insemination of frozen/thawed semen with or without oxytocin administration.

Intrauterine insemination by laparoscopy is required to achieve acceptable lambing rates in ewes when using frozen semen but the procedure has evoked welfare concerns. Oxytocin has been used to dilate the cervix as a means of accessing the uterus during conventional cervical insemination, but its effect on fertility is not well documented. Three hundred crossbred ewes were synchronised in estrus and randomly allocated to one of three insemination procedures using frozen/thawed semen containing 400 x 10(6)/ml progressively motile sperm: single cervical (0.2 ml), multiple cervical (4 x 0.05 ml) or laparoscopic (0.05 ml per uterine horn). The effects of each insemination procedure on lambing rate (percentage of treated ewes lambing) and litter size (lambs per ewe lambing) were tested with and without oxytocin (10 IU given i.m.) prior to fixed-time insemination. Oxytocin did not permit complete cervical penetration in any ewes and neither lambing rate nor litter size was influenced by the number of inseminations. Lambing percentages were 69 and 42 (P < 0.01) for the laparoscopic and cervical insemination methods, respectively, and oxytocin reduced these to 58 (NS) and 10 (P < 0.001) percent, respectively. Corresponding litter sizes for ewes not receiving oxytocin were 1.91 and 1.51 and for those receiving oxytocin, 1.83 and 1.41 (laparoscopic versus cervical, P < 0.02). Thus, in the absence of complete cervical penetration at insemination, 10 IU oxytocin decreased the number of ewes lambing but had no effect on their litter size.

Animals↗

PubMed1999

Cicletanine prevents the excitation-conduction blocks induced by terfenadine in ischemic myocardium.

Terfenadine, a histamine H(1) receptor antagonist, has been associated with clinical ventricular arrhythmias and in vitro excitation-conduction blocks, whereas anti-ischemic and antiarrhythmic effects have been shown with cicletanine, a prostacyclin generation stimulator. We aimed at determining in vitro if cicletanine can protect the ischemic myocardium from excitation-conduction blocks and specifically those induced by terfenadine. In a double-chamber bath, isolated guinea pig ventricular strips were partly exposed to normoxia and partly to ischemic, then reperfused, conditions, in the presence of 10 microM terfenadine, 10 microM indomethacin (prostacyclin generation blocker) or the solvent (dimethylsulfoxide 1:100, control) randomly allocated, and thus either in the absence (n=20) or presence (n=21) of 10 microM cicletanine during the total protocol duration. The multivariate Cox's model was used to predict the excitation-conduction block events and to assess the estimated survival of preparations (excitation-conduction block-free rate). Cicletanine protected the preparations (relative risk=0.08, t=-3.28) from the ischemia-induced excitation-conduction blocks (estimated survival=0.83 versus 0.30 in control), and this effect was abolished by indomethacin (estimated survival=0.35). Terfenadine enhanced 3. 58-fold the risk of occurrence of excitation-conduction blocks during ischemia (t=2.10) and this effect was inhibited by cicletanine pretreatment (estimated survival=0.40 versus 0.10 in untreated preparations). In conclusion, these in vitro findings have provided evidence for (1) protective effects of cicletanine against ischemia-induced excitation-conduction blocks, possibly related to its stimulating activity on local prostacyclin generation, and (2) efficacy of cicletanine to prevent excitation-conduction blocks induced by terfenadine in ischemic cardiac tissue.

Animals↗

PubMed1992

Olive oil, corn oil, and n-3 fatty acids differently affect lipids, lipoproteins, platelets, and superoxide formation in type II hypercholesterolemia.

To evaluate which dietary fat may provide the best response in terms of plasma lipids and lipoproteins and also of platelet aggregability and superoxide formation by white blood cells, 12 type II patients were randomly allocated to three different diets, which provided polyunsaturated fatty acids (corn oil), monounsaturated fatty acids (olive oil), and a supplementation of ethyl esters of n-3 fatty acids to a prudent diet. Olive oil and, more significantly, n-3 ethyl esters lowered total cholesterol best (-2.2% and -5.8%, respectively); the latter diet, as expected, also significantly lowered triglyceridemia (-21.4%). The corn-oil diet exerted a small, statistically significant reduction of high-density-lipoprotein cholesterol (HDL) (-4.3%), and it also lowered plasma total apo B concentrations (-3.8%). n-3 ethyl esters significantly raised both total (+3.1%) and particularly HDL2 cholesterol (+24%). Platelet reactivity was insignificantly reduced by the three regimens, but all three significantly reduced thrombin-stimulated formation of thromboxane B2. Finally, only the n-3 fatty acid supplementation significantly reduced O2- generation by adherent monocytes. Dietary unsaturated fatty acids are generally effective on the plasma lipid and lipoproteins in type II patients, but significant differences may be found between the three tested regimens.

Apolipoproteins↗

PubMed2006

Primary irritant and delayed-contact hypersensitivity reactions to the freshwater cyanobacterium Cylindrospermopsis raciborskii and its associated toxin cylindrospermopsin.

BACKGROUND: Freshwater cyanobacteria are common inhabitants of recreational waterbodies throughout the world; some cyanobacteria can dominate the phytoplankton and form blooms, many of which are toxic. Numerous reports in the literature describe pruritic skin rashes after recreational or occupational exposure to cyanobacteria, but there has been little research conducted on the cutaneous effects of cyanobacteria. Using the mouse ear swelling test (MEST), we sought to determine whether three toxin-producing cyanobacteria isolates and the purified cyanotoxin cylindrospermopsin produced delayed-contact hypersensitivity reactions. METHODS: Between 8 and 10 female Balb/c mice in each experiment had test material applied to depilated abdominal skin during the induction phase and 10 or 11 control mice had vehicle only applied to abdominal skin. For challenge (day 10) and rechallenge (day 17), test material was applied to a randomly-allocated test ear; vehicle was applied to the other ear as a control. Ear thickness in anaesthetised mice was measured with a micrometer gauge at 24 and 48 hours after challenge and rechallenge. Ear swelling greater than 20% in one or more test mice is considered a positive response. Histopathology examination of ear tissues was conducted by independent examiners. RESULTS: Purified cylindrospermopsin (2 of 9 test mice vs. 0 of 5 control mice; p = 0.51) and the cylindrospermopsin-producing cyanobacterium C. raciborskii (8 of 10 test mice vs. 0 of 10 control mice; p = 0.001) were both shown to produce hypersensitivity reactions. Irritant reactions were seen on abdominal skin at induction. Two other toxic cyanobacteria (Microcystis aeruginosa and Anabaena circinalis) did not generate any responses using this model. Histopathology examinations to determine positive and negative reactions in ear tissues showed excellent agreement beyond chance between both examiners (kappa = 0.83). CONCLUSION: The irritant properties and cutaneous sensitising potential of cylindrospermopsin indicate that these toxicological endpoints should be considered by public health advisors and reservoir managers when setting guidelines for recreational exposure to cyanobacteria.

Alkaloids↗

PubMed2004

Effect of dental floating on weight gain, body condition score, feed digestibility, and fecal particle size in pregnant mares.

OBJECTIVE: To investigate the effect of routine dental floating on weight gain, body condition score, feed digestibility, and fecal particle size in pregnant mares fed various diets. DESIGN: Randomized controlled clinical trial. ANIMALS: 56 pregnant mares. PROCEDURE: Mares were randomly allocated to 1 of 4 feed groups (n = 14 mares/group). All horses were sedated and an oral examination was performed, after which dental floating was performed on 7 horses in each group. Body weight was measured, and a body condition score was assigned before and at various times for 24 weeks after dental floating. Feed digestibility and fecal particle size were analyzed 7 and 19 weeks after dental floating. RESULTS: Weight gain, change in body condition score, feed digestibility, and fecal particle size were not significantly different between horses that underwent dental floating and untreated control horses. In contrast, weight gain was significantly associated with feed group. In the control horses, neither the number of dental lesions nor the presence of any particular type of lesion at the time of the initial oral examination was significantly associated with subsequent feed digestibility. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dental floating does not result in significant short-term changes in body weight, body condition score, feed digestibility, or fecal particle size in healthy pregnant mares. Further studies are necessary to determine the clinical utility of regular dental floating in apparently healthy horses.

Animals↗

PubMed2005

Dynamics and persistence of Mycoplasma hyopneumoniae infection in pigs.

The purpose of this study was to describe the dynamics (shedding and transmission) of Mycoplasma hyopneumoniae infection within a population of swine and to determine the duration of the infection (persistence) through the identification of the agent in bronchial samples. Sixty-three 2-month-old pigs were used in this study. The pigs (n = 28) were experimentally infected by the intratracheal route with M. hyopneumoniae and considered as seeder pigs. The remaining pigs (n = 32) were not inoculated and randomly allocated to 2 different groups: direct contact exposure pigs (n = 12) and indirect contact exposure pigs (n = 20). Blood samples and nasal swabs were collected throughout the study on days 0, 28, 35, 42, 49, 63, 91, and 119 postinfection. To assess the duration of M. hyopneumoniae infection, 9 seeder and 6 contact exposure pigs were slaughtered at days 155 (group 1), 170 (group 2), and 185 (group 3) postinfection. Direct contact pigs showed evidence of infection on day 28 by polymerase chain reaction (PCR) and on day 35 by serology. The indirect contact exposure pigs presented a very delayed and slow seroconversion pattern; they did not present evidence of transmission until 42 d after the infection of seeder pigs. Identification of M. hyopneumoniae in bronchial swabs was confirmed by nested-PCR from days 155 to 185 postinfection. At the last slaughter date, 77.7% and 100% of the seeders and contact exposure pigs, respectively, tested positive. The results of this study reconfirmed direct infection of M. hyopneumoniae and suggest that indirect transmission can occur in a population. Finally, duration of the infection in this study was longer than previously described.

Animals↗

PubMed1995

Effect of a pneumoperitoneum on the extent and severity of peritonitis induced by gastric ulcer perforation in the rat.

Laparoscopic surgical repair of perforated gastroduodenal ulcer is technically feasible. To study the effect of a pneumoperitoneum on the extent and severity of peritonitis this animal study was devised. In rats gastric ulceration was induced by instillation of ethanol (50%, 2 ml) and followed by gastrotomy to simulate perforation. Animals were randomly allocated to pneumoperitoneum (PP) and control groups. In PP groups CO2 was insufflated intraperitoneally 6, 9, 12, and 24 h after gastrotomy. In controls the abdomen was only punctured. Animals were sacrificed 5 h after the end of PP or abdominal puncture. Blood cultures and intraabdominal swabs were assessed. A peritonitis severity score (PSS) based on histologies from peritoneum, liver, left kidney, spleen, and first jejunal loop was estimated. Six and 9 h after gastrotomy no significant differences between the PP and control groups were observed; 12 h after gastrotomy cultures of blood samples and abdominal swabs were positive in 67% and 75% in the PP group compared to 42% (P < 0.05), and 42% (P < 0.05) in controls. The mean PSS was 20.8 (standard deviation [SD] 2.2) in the PP group compared to 11.3 (1.5) (P < 0.01) in controls; 24 h after gastrotomy cultures of blood samples and abdominal swabs were positive in 83% and 100% in the PP group compared to 42% (P < 0.05) and 50% (P < 0.01) in controls. The mean PSS was 22.1 (1.5) in the PP group compared to 11.8 (2.4) (P < 0.01) in the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Effect of lidocaine on in vivo hepatic function.

Lidocaine is administered to assess donor or recipient liver function during hepatic transplantation. This study was performed to determine whether lidocaine administered at a constant concentration affected hepatic function or had demonstrable effects on hepatocellular ultrastructure. Fourteen pigs were randomly allocated to receive either a two-stage infusion of lidocaine hydrochloride or of saline. Transhepatic blood samples were taken and ultrasonic portal venous and hepatic arterial blood flow readings made on animals anesthetized with isoflurane in nitrous oxide. Liver biopsies were taken for histological analysis and determination of adenine nucleotide status prior to and after 2 hr of the two-stage infusion. A mean systemic constant plasma lidocaine concentration of 5.9 micrograms/ml was achieved during the second hour of infusion. There were no differences between the two groups in a large number of indices of hepatic function and plasma composition prior to and during the second hour of the respective infusions. Hepatic blood flow was also similar at these times. On histological examination there were no electron microscopic changes that could be specifically attributed to the administration of lidocaine. However, there were progressive changes with time. This study suggests that in anesthetized pigs a constant lidocaine concentration of about 6 micrograms/ml has no detrimental effect on hepatic function. Progressive hepatic ultrastructural changes occurred that could not be attributed to the administration of lidocaine. These may be the result of anesthetic administered or the surgery performed.

Animals↗

PubMed1984

The effect of short term postoperative intravenous feeding upon cell-mediated immunity and serum suppressive activity in well nourished patients.

Thirty-four patients undergoing elective abdominal aortic aneurysmectomy were studied, and they were randomly allocated to a "fed group receiving amino acid dextrose solutions intravenously and fat emulsions or an "unfed" group receiving standard postoperative care. Cell-mediated immunity was measured by lymphocyte count, the in vitro response to the T-cell mitogen PHA and determination of T-cell subsets using monoclonal antibodies. Serum suppressive activity was measured by the ability of the sera of the patient to suppress the response of normal lymphocytes to PHA. Feeding was continued for three to five days postoperatively until satisfactory oral intake was achieved. There was no significant improvement in lymphocyte count or blastogenesis postoperatively in the "fed" group, and operation did not lead to any alteration in the ratio of T-cell subsets, although there was a fall in T-cell count (OKT3 positive cells). We conclude that short term parenteral nutrition in well nourished patients, postoperatively, does not abrogate the depression of cell-mediated immunity which occurs after extensive operative procedures.

Aged↗

PubMedDate not supplied

Calibrated phase II clinical trials in oncology.

This paper proposes the use of calibrated designs in phase II oncological clinical trials and evaluates their statistical properties in terms of power recovery and cost. A calibrated phase II design for a new cancer treatment for a specific tumour, e.g. colo-rectal, consists of random allocation of patients to receive either the investigational treatment or a standard treatment known to have activity at a certain level in phase II trials (e.g. 5 FU, expected response proportion = 0.20). Patients assigned to the standard treatment form the calibration group. The calibration group is not a control group in the traditional sense and one does not conduct a formal efficacy comparison between the investigational treatment group and the calibration group. Instead, one uses the calibration group to evaluate whether the sample of patients who receive the investigational treatment has the capability of showing a response. If the data do not support the hypothesis that the expected response proportion prevails in the calibration group, one declares the investigational group results suspect and recommends a second trial. Assuming acceptable results of the second trial, we use binomial calculations to find the effect of the calibration design on power recovery and relative cost. We show that when an unrepresentative sample occurs, calibration designs generally recover 90 per cent or more of nominal power at a cost of three to fivefold increase in sample size. We recommend for calibrated phase II trials a 'master protocol' approach in which several investigational treatment arms share one concurrent calibration group.

Calibration↗

PubMed1994

The need to retrieve the dropped stone during laparoscopic cholecystectomy.

The effect of bile and gallstones on the peritoneal cavity was evaluated in an experimental animal study. Ninety male Sprague-Dawley rats were randomly allocated to one of six groups (n = 15). Groups 1 to 3 received an intraperitoneal injection (2 mL) of saline, sterile bile, and infected bile, respectively. Groups 4 to 6 underwent a lower midline abdominal incision (3 to 5 mm). In groups 4 and 5, a single gallstone (< 3 mm diameter) was placed in the right upper quadrant and, after closure of the wound, the animals were injected with sterile bile and infected bile, respectively. Group 6 animals underwent laparotomy alone, followed by injection of sterile saline (2 mm). All animals were killed at 4 weeks and the peritoneal cavity was carefully examined. No intra-abdominal lesions were noted in groups 1 to 3. Adhesions were noted in 11 (73%) and 10 (67%) animals of groups 4 and 5, respectively. Two intra-abdominal abscesses were noted in group 4 animals. No intra-abdominal lesions were noted in any group 6 animals. This study suggests that bile in combination with gallstones in the peritoneal cavity is associated with an increased risk of intra-abdominal adhesion formation and possible abscess formation, and that every attempt should be made to retrieve stones lost during cholecystectomy.

Animals↗