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The Edinburgh randomised trial of screening for breast cancer: description of method.

Edinburgh was selected as one of the centres in the UK Seven-year Trial of Breast Screening of women aged 45-65 which began in 1979. Subsequently, our study was extended to a randomised trial with its own control population within the city. Half the practices were randomly allocated for screening, giving a cluster sampling of women. The total number in the trial is 65,000. Women with previously diagnosed breast cancer are excluded. Women allocated for screening are invited to the clinic and screened according to the procedures specified in the U.K. protocol, having clinical examination every year and mammography on alternate years. The two modalities of screening are assessed independently and the role of nurses is being evaluated. Breast cancer incidence is monitored by pathology register and the local cancer registry office and deaths from the General Register office. Long-term follow-up will be obtained through flagging at NHS Central Register. To determine the value of screening, standard statistical methods will be used to compare breast cancer mortality rates in the whole of the screening population with that of the controls. This trial has a power of 83% of detecting a reduction in mortality of 35% after 7 years of follow-up and a power of 95% of detecting a similar reduction at 10 years (alpha = 0.05, one-sided test).

Breast Neoplasms↗

Varying effect of dietary lipids and azoxymethane on early stages of colon carcinogenesis: enumeration of aberrant crypt foci and proliferative indices.

Animal models have been used extensively to study the role of diet in the etiology and prevention of colon cancer. It is recognized that several experimental variables affect disease modulation and outcome. Our objective was to determine whether an interaction between the dose of carcinogen used and dietary factors exist, using aberrant crypt foci (ACF) as a biological end point. Sprague-Dawley male rats were injected with a low or a high dose of azoxymethane (AOM, 5 mg or 20 mg per kg s.c.) or saline (0.2 ml/animal s.c.), and randomly allocated to four diet groups (N = 8/group) 1 week later. Diets varied with respect to type of fat (corn or olive oil) and levels of fat: normal (5 g/100 g) corn or olive oil (CO or OO), or high (23.5 g/100g) corn or olive oil (HCO or HOO). After 8 weeks of dietary treatment animals were injected with colchicine (1 mg/kg). Two and a half hours later they were killed and their colons assessed for number of ACF, number of crypt/focus (crypt multiplicity), and the size of ACF as well as the number of cells in metaphase and their location in the crypt section. The low dose of AOM induced fewer ACF and ACF with higher crypt multiplicity than did the high dose of AOM. Dietary fats exerted a variable effect on ACF, depending on the dose of AOM. In low-dose AOM groups, both CO diets exerted a growth-enhancing effect on ACF compared with OO diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

Significance of administration of fat emulsion: hepatic changes in infant rats receiving total parenteral nutrition with and without fat.

Total parenteral nutrition (TPN) is associated with cholestasis and hepatic steatosis, which can be lethal in infants who cannot be fed orally. The present animal study focused on the metabolic complications in the liver that may occur due to the excessive administration of fat-free TPN. Thirty infant (3-week-old) male SD rats weighing 60-70 g were randomly allocated to five groups (n = 6): the OD group received an oral diet, the FT group received an oral diet and was fasted overnight on the last day of experiment before sacrifice, the 0% fat group received TPN without fat, the 20% fat group received TPN with 20% of calories from fat emulsion, and the 40% fat group received TPN with 40% of calories from fat emulsion. All TPN regimens were isocaloric, isonitrogenic, and administered for 4 days. In the 0% fat group, plasma levels of liver enzymes were significantly higher than in the other groups. Pathological examination showed hepatomegaly and severe fatty changes without cholestasis in the 0% fat group. The results of this study in infant rats indicate the importance of including fat in the TPN regimen in order to prevent the abnormal hepatic changes associated with the excessive administration of fat-free TPN.

Alanine Transaminase↗

Second generation effects of maternal alcohol consumption during pregnancy in rats.

1. Previous studies have shown that when female rats are administered alcohol during pregnancy there are adverse effects on their progeny, including decreased birth weight and delayed neuromotor development. Evidence from several sources suggests alcohol exposure may contribute to cytogenetic abnormalities, suggesting the possibility of cross generational effects from prenatal exposure. 2. On day 1 of gestation female rats were randomly allocated to the Alcohol group, which received a liquid diet containing 5% (v/v) ethanol solution until parturition, the Sucrose control group, which received an identical diet, except that sucrose had been isocalorically substituted for ethanol, or the Chow control, which received standard laboratory chow. 3. When the offspring of these rats reached adulthood they were mated with drug-free rats and the development of their offspring was monitored. 4. In comparison with female pups whose sires had been exposed to alcohol in utero, the weight of pups descended from fetally-exposed dams increased more slowly from day 1 to day 7. 5. At five days of age, significant differences favouring the two control groups were found in latency to right for pups descended from fetally-exposed dams. 6. These data suggest that the effects of prenatal exposure to alcohol are more pervasive than previously thought and affect female pups to a greater extent than males.

Alcohol Drinking↗

Effect of nutrition on embryonal mortality in gilts: association with progesterone.

The effect of the timing of nutritional changes during the immediate period after mating on early embryonal survival and of progesterone as a potential mediator of such changes was studied. A total of 82 gilts were initially fed 2.5 kg.gilt-1.d-1 for one estrous cycle before they were inseminated at 16 and 24 h after the onset of estrus (d 0) using fresh, pooled semen. After AI, gilts were randomly allocated to one of the three feeding regimens, normal NRC allowance of 1.5 x maintenance per day from d 1 (Group N1) or d 3 (Group N3) or an allowance of 2 x maintenance from d 1 (Group H1). All gilts were fed on an individual basis. Single blood samples were collected 72 h after first detection of standing estrus. From d 15 onward, all gilts were fed 1.8 kg/d until they were slaughtered on d 28 +/- 3. Total and viable empryonal survival were affected by dietary treatment (P = .044 and .027, respectively), and viable embryonal survival in group N1 was greater than in group H1 (84.7 +/- 4.5 vs 64.5 +/- 7.6%; P < .05). Plasma progesterone was greater in group N1 than in groups N3 and H1 (10.5 +/- 1.0 vs 3.7 +/- .8 and 4.5 +/- .7 ng/mL, respectively; P < .05). The timing of the change in feed allowance after mating is therefore crucial for demonstrating effects of nutrition on embryonal survival in gilts, and progesterone may mediate these effects.

Animal Nutritional Physiological Phenomena↗

A comparison of the retention of tooth-colored posts.

OBJECTIVE: The aim of this in vitro study was to compare the retention of five different esthetic post systems of similar dimensions in extracted teeth using titanium posts as controls. METHOD AND MATERIALS: Sixty recently extracted single-rooted, caries-free teeth were sectioned horizontally and mounted in acrylic resin. The samples were randomly allocated into six groups of 10 for post preparation. Post space preparation was carried out according to the individual manufacturer's instructions. All posts were bonded using Panavia F. A 4-mm hollow, metal sleeve was luted over the free end of each post prior to mounting in a universal testing machine, and the forces required to dislodge the posts using a cross-head speed of 5 mm/min were recorded. RESULTS: It was found that the parallel-sided Lightposts were significantly more retentive than all of the other posts. Parapost Fibrewhite posts were more retentive than tapered Lightposts and Snowposts. There was no significant difference between the retention of stainless steel Paraposts and any of the other groups. CONCLUSIONS: Serrated parallel-sided stainless steel posts were no more retentive than either parallel-sided or tapered tooth-colored posts in this study. When all groups were considered, post dimension appeared to influence retention, with parallel-sided posts being more retentive than tapered posts.

Ceramics↗

Single dose cefuroxime/metronidazole versus metronidazole alone in elective colorectal surgery.

Sixty assessable patients undergoing elective colonic and rectal surgery were randomly allocated to receive prophylaxis with a combination of 1.5 g cefuroxime plus 500 mg metronidazole or 500 mg metronidazole alone as single doses by the intravenous route, given at the beginning of anesthesia. The two groups were matched for age, sex, malignancy, and type of operation. Primary wound infections were observed in one patient (3.7%) in the combination group and six (18.2%) in the group given metronidazole alone. This trend was not statistically significant. Bacteriologic examination of the anastomoses, abdominal walls, and wounds showed significantly more sterile cultures in the combination group, although more aerobic cefuroxime-resistant isolates were seen in this group. There is no evidence that the emergence of resistant strains had any influence on the outcome of patients in the study. It was concluded that an appropriate antibiotic prophylactic regimen for colorectal surgery should be directed against aerobic and anaerobic organisms. Cefuroxime plus metronidazole is an effective regimen for the prevention of postoperative infection.

Adult↗

[Comparison of endometrial histology and ultrastructure during different ovarian stimulation protocols in hamsters].

OBJECTIVE: To evaluate the influence of ovarian stimulation by pregnant mare's serum gonadotropin(PMSG) with or without gonadotropin releasing hormone agonist (GnRH-a) on endometrial histology and ultrastructure in hamsters. METHODS: Thirty hamsters were randomly allocated into 3 groups. (1) LA + PMSG group: Leuprolide acetate (LA) was given first for desensitizing the pituitary, then PMSG added for ovarian stimulation. (2) PMSG group was injected with PMSG only. (3) Control group was given with saline of same volume as groups LA + PMSG and PMSG on the same time schedule. Endometrial histology and ultrastructure were investigated by light microscope and electron microscope. RESULTS: Comparing to the controls, the changes of endometrial histology in group of LA + PMSG was not significantly different, but its ultrastructure had marked atterations: mitochondria swelling, undifferentiated crista and no basket-like structure. Delayed endometrial maturation was frequently found in group PMSG (P < 0.01), and the ultrastructure showed poorly developed mitochondria. CONCLUSION: The degree of endometrial maturation varied considerably with different ovarian stimulation protocols. Ovarian stimulation with GnRH-a was better than PMSG alone, because the protocol LA + PMSG, in hamsters, facilitated the formation of a physiologic endometrium. But the protocol with GnRH-a still had a negative effect on endometrial ultrastructure.

Animals↗

The haemodynamic and metabolic effects of epinephrine in experimental hyperdynamic septic shock.

OBJECTIVE: To study the effect of epinephrine (EPI) infusion on vital organ blood flow and metabolic variables during sepsis. DESIGN AND SETTING: Randomised placebo-controlled animal trial in an animal laboratory. ANIMALS: Seven merino cross-ewes. INTERVENTIONS: Chronic implantation of flow probes (aorta, renal, mesenteric and coronary artery and sagittal sinus). Induction of sepsis by intravenous injection of E. coli. Random allocation of sheep to EPI (0.4 microg kg(-1) min(-1)) or vehicle for 6 h. MEASUREMENTS AND RESULTS: E. coli induced hypotension and hyperlactataemia and increased cardiac output, renal, mesenteric and coronary blood flows. Compared to vehicle, EPI restored mean arterial blood pressure (69 vs. 86 mmHg) and further increased cardiac output (6.4 vs. 7.1 l/min). EPI, however, decreased renal blood flow (330 vs. 247 ml/min) and renal conductance. EPI also reduced mesenteric and coronary conductance without changes in flows. Compared to vehicle, EPI increased urine output (293 vs. 544 ml/6 h) but not creatinine clearance. EPI increased lactate (1.8 vs. 15.7 mmol/l) with accompanying acidosis (serum bicarbonate: 25.2 vs. 15.7 mmol/l), hyperglycaemia (2.6 vs. 13.5 mmol/l) and hypokalaemia (4.3 vs. 3.0 mmol/l). CONCLUSIONS: Hyperdynamic sepsis increased blood flow to heart, gut and kidney. Although EPI infusion further increased cardiac output, blood pressure and myocardial performance, it was also associated with potent metabolic effects, decreased mesenteric, coronary and renal conductance and a significant reduction in renal blood flow.

Animals↗

Forward mandibular positioning enhances condylar adaptation in adult rats.

The aim of this investigation was to assess quantitatively the adaptive changes in the condyles of adult rats to forward mandibular positioning. The level of types II and X collagen expressed in the condyles of adult rats was compared with that formed in response to forward mandibular positioning and the levels of expression were correlated to the amount of bone formed in response to mandibular advancement. Seventy-eight 120-day-old female Sprague-Dawley rats were included in this study. The rats were randomly allocated to six groups. Each group consisted of nine rats with bite-jumping devices and four untreated controls. The animals in each group were sacrificed on days 3, 7, 14, 21, 30, and 60. Immunostaining was used for the detection of types II and X collagen, while Alcian blue-PAS was used to observe the extracellular matrix and new bone formation. The results showed that new cartilage was formed in the posterior condyle. The highest level of expression of types II and X collagen were present on day 21, the amount of increase was 247.99 and 540.08 per cent, respectively. The highest level of new bone formation was measured at day 30 of advancement when the amount of increase in new bone formation was 318.91 per cent. These findings indicate that forward mandibular positioning causes changes in the biophysical environment of the temporomandibular joint (TMJ) of adult rats that leads to condylar adaptation.

Adaptation, Physiological↗

Dose-finding study of amorolfine cream (0.125%, 0.25% and 0.5%) in the treatment of dermatomycoses.

A total of 725 patients with mycosis of the skin folds, large areas of the body or feet were entered into this double-blind, dose-finding study. Treatment with 0.125, 0.25 or 0.5% amorolfine cream was randomly allocated to patients. The cream was applied once daily for 4 weeks on average. At screening, in 527 patients evaluated for efficacy, a total of 533 pathogens were isolated: T. rubrum (322), T. mentagrophytes (84), E. floccosum (45), M. canis (42), other dermatophytes (14), C. albicans (24) and other yeasts (2). One week after the end of treatment, the culture was negative in 80.5, 81.3 and 84.8% of patients treated with 0.125, 0.25 or 0.5% amorolfine cream, respectively. The differences were not statistically significant. Forty-four out of 714 patients evaluated for safety had local adverse events: 14 (5.8%), 13 (5.5%) and 17 (7.1%) in the amorolfine cream 0.125, 0.25 and 0.5% groups, respectively. Due to local adverse events, six patients (2.5%) in the 0.125% group, six patients (2.6%) in the 0.25% group and seven patients (2.9%) in the 0.5% group discontinued the trial treatment. The most common adverse events were burning, itching, erythema and scaling. No systemic adverse events were reported.

Administration, Topical↗

Pharmacokinetics of UMF-078, a candidate antifilarial drug, in infected dogs.

The pharmacokinetics of the filaricidal benzimidazole compounds UMF-078 and UMF-289 were evaluated in beagle dogs experimentally infected with Brugia pahangi. Twenty-four infected microfilaremic beagles were selected and randomly allocated into 4 treatment groups of 6 dogs each: oral (PO) UMF-078, PO UMF-289 (the HCl salt form of UMF-078), intramuscular (IM) UMF-078, and untreated controls. Equivalent doses of 50 mg/kg of the free base were given twice a day for 3 days to the 3 groups of treated dogs. Oral absorption is rapid compared with IM dosing; the absorption half-life (K01-HL) for the IM treatment is approximately 14 hr compared with 1 and 2 hr for the PO regimen of salt and free base forms, respectively. The elimination half-lives (K10-HL) for the PO regimens are 13 and 15 hr for the salt and free base forms, respectively. Because of sustained absorption following IM dosing, the K10-HL is prolonged. In contrast to oral administration, IM dosing of UMF-078 provides sustained, relatively low plasma drug levels, with good tolerance and efficacy.

Administration, Oral↗

BCG and vole bacillus vaccination in adolescence and mortality from leukaemia.

In total, 28 deaths from leukaemia are known to have occurred among the 54,239 participants in the Medical Research Council tuberculosis vaccines trial (initially aged about 14 years), from its beginning in 1950 to the end of 1979. There is evidence that this total is likely to be very nearly complete. During the entire period (average 27.1 years) the leukaemia mortality per million person-years was 25 in the BCG vaccinated group, 20 in the vole-bacillus vaccinated group, and 21 in the randomly-allocated unvaccinated (control) group. Although there was neither a benefit nor a disadvantage from vaccination over the whole period, detailed figures suggested that there may have been a beneficial effect against leukaemia during the first 15 years after entry (that is between age 15 and 30 years) and a deleterious effect after longer intervals (or above the age of 30 years). Alternatively this swing may simply represent an unusual chance fluctuation. There has been no sign in recent years of any substantial decrease in leukaemia mortality in England and Wales at ages 15-29 years, although the proportion of children given BCG vaccine at about age 13 years has risen from less than 1 per cent (for the cohort aged 15-19 years in 1951-1955) to more than 70 per cent 25 years later. It has therefore been provisionally concluded that chance is the explanation for the apparent swing from prevention to enhancement, and that BCG vaccination at age 13-14 years in Great Britain does not affect subsequent mortality from leukaemia.

Adolescent↗

The effect of different doses of gonadorelin on ovarian follicle dynamics in river buffalo (Bubalus bubalis).

The objective of this study was to determine the response of the ovarian dominant follicle to the different doses of GnRH in river buffalo. The estrous cycle of 12 river bufflaloes was synchronized using norgestomet implant for 12 days in association with two injections of prostaglandin F2alpha analogue on Days 0 and 7 of implant insertion. On Day 6 or 7 of the ensuing cycle (Day 0 of the experiment), females received a norgestomet implant in conjunction with two prostaglandin injections on Days 0 and 1. On Day 6 of the experiment, females were randomly allocated into three groups. At this time, Group 1 and 2 females were given an i.m. injection of 50 or 100 microg Gonadorelin, respectively. Group 3 females did not receive any further treatment and were considered as control. All females were given prostaglandin on Day 12 and implants were removed on Day 13 of the experiment. The results revealed that in the control group, ovarian dominant follicle became persistent throughout the experiment; whereas, the persistent dominant follicle in all females belonging to Group 2 (100 microg GnRH) and one female in Group 1 (50 microg GnRH) ovulated within 48 h, subsequent with an emergence of a new follicular wave and an increase in plasma progesterone concentration within 72 and 96 h after GnRH injection, respectively. In conclusion, 100 microg of Gonadorelin seems to be the most effective dose to induce ovulation followed by an emergence of a new follicular wave in river buffalo.

Animals↗

Adverse effect of therapeutic vasoconstrictors in experimental acute pancreatitis.

Alpha-adrenergic drugs commonly are used to treat hypotension resulting from severe acute pancreatitis. It was shown previously that although systemic arterial pressure is increased by phenylephrine, pancreatic microcirculatory perfusion is decreased. Because inadequate tissue perfusion may be critical in the progression of edematous pancreatitis to parenchymal necrosis, it was hypothesized that vasoconstrictors might be harmful in pancreatitis. Therefore the effect of phenylephrine on cerulein-induced mild pancreatitis were studied. Sprague-Dawley rats (n = 54) were randomly allocated to 6 experimental groups and subjected to the following infusion regimens: (1) cerulein (cae) + phenylephrine (phe), (2) cae + saline (NS), (3) NS + phe, (4) cae + phenoxybenzamine (pbz) + phe, (5) NS + pbz + phe, and (6) NS. Initial and terminal hematocrit, serum amylase activity, and blood ionized calcium concentration were determined. The animals were killed 9 hours after starting the infusion. Macroscopic and histologic changes were scored by a 'blinded' pathologist. Phenylephrine increased the severity of cerulein-induced pancreatitis as manifested by statistically significant adverse changes in serum amylase, hematocrit, ionized calcium, peripancreatitic soap formation, and acinar cell vacuolization. These changes were antagonized by alpha-adrenergic receptor blockade with phenoxybenzamine. It is concluded that phenylephrine is deleterious in acute experimental pancreatitis, the first demonstration of such an effect by a pharmacologic vasoconstrictor, and suggested that microcirculatory changes may be important in the transition of mild to severe pancreatitis. Caution in the use of vasoconstrictor drugs in patients with acute pancreatitis is recommended.

Acute Disease↗

In-vitro strength of flexor-tendon repairs.

OBJECTIVE: To compare the standard Tajima technique for flexor-tendon repair of the hand with three new techniques with respect to strength and technical ease of the repair and bulk at the repair site. DESIGN: A randomized analysis of human cadaver flexor digitorum superficialis tendon repairs. SETTING: A musculoskeletal research laboratory at a university-affiliated health centre. MATERIAL: Thirty-nine fresh-frozen cadaveric flexor digitorum superficialis tendons from index, long and ring fingers harvested and divided transversely. The tendons were randomly allocated for repair by the current standard technique or one of three new techniques. INTERVENTIONS: The standard Tajima (modified Kessler) technique, and the Halsted, Savage or Silfverskiold technique. MAIN OUTCOME MEASURES: The time to perform each repair, the cross-sectional dimension and the load to failure of the tendon repairs. RESULTS: The Savage repair tolerated the highest loads, followed by the Halsted, Silfverskiold and Tajima repairs. The Silfverskiold technique was the least time-consuming to perform, followed by the Tajima, Halsted and Savage repairs. All of the techniques increased the cross-sectional dimensions of the tendon: the Silfverskiold repair by at least 50% and the Savage repair by over 100%. Although none of the techniques tested performed ideally, all three new techniques provided greater initial static strength than the standard Tajima method. CONCLUSION: Further in-vitro and in-vivo studies of these new techniques of flexor-tendon repair of the hand are necessary to optimize the treatment of these injuries.

Biomechanical Phenomena↗

The effects of repeated doses of vasopressin or epinephrine on ventricular fibrillation in a porcine model of prolonged cardiopulmonary resuscitation.

This study evaluated ventricular fibrillation mean frequency and amplitude to predict defibrillation success in a porcine cardiopulmonary resuscitation (CPR) model using repeated administration of vasopressin or epinephrine. After 4 min of cardiac arrest and 3 min of CPR, 10 pigs were randomly assigned to receive either vasopressin (early vasopressin: 0.4, 0.4, and 0.8 units/kg, respectively, n = 5) or epinephrine (early epinephrine: 45, 45, and 200 microg/kg, respectively, n = 5). Another 11 animals were randomly allocated after 4 min of cardiac arrest and 8 min of CPR to receive every 5 min either vasopressin (late vasopressin: 0.4 and 0. 8 units/kg, respectively, n = 5) or epinephrine (late epinephrine: 45 and 200 microg/kg, n = 6). Ventricular fibrillation mean frequency and amplitude on defibrillation were significantly higher in the vasopressin groups than in the epinephrine groups, respectively. In vasopressin versus epinephrine animals, mean frequency immediately before defibrillation was 9.6 +/- 1.5 Hz vs 7. 0 +/- 0.7 Hz (P < 0.001), mean amplitude was 0.65 +/- 0.26 mV vs 0. 21 +/- 0.14 mV (P < 0.001, and coronary perfusion pressure was 27 +/- 9 mm Hg vs 8 +/- 4 mm Hg (P < 0.00001), respectively. In contrast to no epinephrine animals, all vasopressin animals were successfully defibrillated and survived 1 h (P < 0.05). Mean fibrillation frequency and amplitude predicted successful defibrillation and may serve as noninvasive markers to monitor continuing CPR efforts. Furthermore, vasopressin was superior to epinephrine in maintaining these variables above a threshold necessary for successful defibrillation.

Animals↗

The effect of diminazene aceturate on cholinesterase activity in dogs with canine babesiosis.

A clinical trial was designed to evaluate the effects of diminazene aceturate and its stabiliser antipyrine on serum pseudocholinesterase (PChE) and red blood cell acetylcholinesterase (RBC AChE) in dogs with babesiosis. The trial was conducted on naturally occurring, uncomplicated cases of babesiosis (n = 20) that were randomly allocated to groups receiving a standard therapeutic dose of diminazene aceturate with antipyrine stabiliser (n = 10) or antipyrine alone (n = 10). Blood was drawn immediately before and every 15 minutes for 1 hour after treatment. Plasma PChE showed a 4% decrease between 0 and 60 min within the treatment group (p < 0.05). No statistically significant differences were found between the treatment and control groups at any of the time intervals for PChE. There was an increase in RBC AChE activity at 15 min in the treatment group (p < 0.05). No significant differences were found between the treatment and control groups at any time interval for RBC AChE. In view of the difference in PChE, samples from additional, new cases (n = 10) of canine babesiosis were collected to identify the affect of the drug over 12 hours. No significant depression was identified over this time interval. The results suggests that the underlying mechanism in producing side-effects, when they do occur, is unlikely to be through cholinesterase depression.

Acetylcholinesterase↗