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Prophylactic amantadine dose and plasma concentration-effect relationships in healthy adults.

Amantadine dose, plasma concentration, prophylactic and adverse effect relationships for prevention of influenza A virus infection in healthy young adult subjects were investigated in a double-blind, placebo-controlled study. Seventy-four subjects with hemagglutination inhibition antibody titers less than or equal to 16 against an attenuated influenza A virus AF9/Montreal/3/72 (H3N2) were randomly allocated to groups taking 0 (placebo), 25, 100, or 150 mg amantadine syrup prophylactically twice a day for 31 doses. Eighteen other subjects were randomly allocated to control groups for investigation of drug toxicity (150 mg) or concurrent other virus infection (placebo). Steady-state trough plasma concentrations were 110 +/- 39, 302 +/- 80, and 572 +/- 207 ng/ml (X +/- SD) for the three amantadine doses and increased out of proportion to dose. Prophylaxis groups were challenged intranasally with virus after the fifth dose at steady state; control subjects received saline solution. No subject became ill. Input virus was recovered 48 or 72 hr after challenge from nose or throat swabs of nine of 21 subjects taking placebo, one of 18 subjects taking 100 mg amantadine, three of 18 subjects taking 25 mg amantadine, and six of 17 subjects taking 150 mg amantadine. There were no differences in seroconversion rates or adverse symptoms. Our data do not support a change in the recommended amantadine prophylactic dose for influenza A virus infection in healthy young adults. We defined trough steady-state plasma concentrations associated with the recommended amantadine dose of 100 mg twice a day that should be mimicked in devising dose schedules for populations with differing amantadine kinetics.

Adolescent

Effects of skirting on processing characteristics of Targhee wool.

Ninety mature Targhee ewes were randomly allocated to nine lots. Lots were randomly assigned to three fleece preparation treatments: 1) nonskirted (control); 2) bellies removed, in which bellies and topknots were removed on the shearing floor; and 3) skirted, in which bellies and topknots were removed and remaining fleece was thrown on a table and lightly skirted. Bellies and topknots composed about 6 to 7% of the fleece weight. An additional 6.6% was removed when fleeces were skirted. Top fiber diameters were not affected (P greater than .10) by skirting. Although not significant (P greater than .10), percentage yield, vegetable content, percentage of noilage, top fiber length, and yellowness indexes tended to be most desirable for skirted lots and least desirable for unskirted lots. Lots with bellies removed were intermediate. Removal of bellies reduced vegetable contamination by 8.4%, with an additional reduction of about .5% by further skirting. Skirting reduced the number of fibers less than 25.4 mm (P less than .10) by 42%. Minimal colored fiber contamination of top was observed. One colored fiber per 15 g of top was detected in two lots of the treatment with bellies removed. All other lots contained no colored fibers. All wools evaluated were well below industry limits set for use in high-quality white or pastel fabrics. All skirted lots of wool evaluated in this study had improved processing characteristics for all processing traits evaluated.

Animal Husbandry

Combined luteinizing hormone releasing hormone analogue and exogenous gonadotrophins for the treatment of infertility associated with polycystic ovaries.

This study was designed to compare the results of treatment with, firstly, exogenous gonadotrophins, with (57 cycles) and without (65 cycles) pretreatment with a superactive analogue of luteinizing hormone releasing hormone (LHRH) and, secondly, pure follicle stimulating hormone (FSH) (50 cycles) with those of human menopausal gonadotrophin (HMG) (72 cycles) in 46 women with clomiphene-citrate-resistant anovulation associated with polycystic ovaries. Patients randomly allocated to the analogue group received buserelin (Suprefact, Hoechst, UK, Ltd, Hounslow, Middlesex), 800 micrograms/day by nasal insufflation and when hypogonadism was achieved, patients were again randomly allocated for ovarian stimulation with either FSH or HMG. Controls received FSH or HMG alone. Patients pretreated with the analogue had similar pregnancy and ovulation rates, needed larger doses and more days of gonadotrophin therapy and had more ovarian overstimulation than those receiving no pretreatment. The role of superactive LHRH analogues for induction of a single ovulation for in-vivo fertilization is thus uncertain. Pure FSH had no advantages over HMG, the LH content of HMG having no deleterious effect on the ovary.

Adult

A headache protocol for nurses: effectiveness and efficiency.

To test the effectiveness and efficiency of a nurse-administered protocol for headache in the primary care setting, we conducted a prospective controlled trial. Two hundred three randomly allocated patients were evaluated by nurses using the protocol who managed independently 55.2% of the patients and received physician consultation on the others. A total of 193 patients were randomly allocated to the physician-control group. Nurse-protocol group patients experienced equivalent symptomatic relief and expressed significantly greater satisfaction with the care they had received than did patients in the physician-control group. A retrospective study of the presenting findings in patients with serious diseases of the CNS provided evidence supporting the safety of the protocol logic. We conclude that nurse-protocol management of headache in this primary care practice was effective and efficient.

Ambulatory Care

Chlorthalidone does not increase the hypotensive effect of nifedipine in essential hypertensives: a crossover multicentre study.

To determine whether the combination of nifedipine + chlorthalidone exerts an additive antihypertensive effect when compared with single-drug treatment, we studied 66 uncomplicated essential hypertensives, with diastolic blood pressure of greater than 100 and less than 115 mmHg. At the end of a 1-month washout placebo period, using a double-blind crossover design, the patients were randomly allocated to nifedipine (20 mg twice a day), chlorthalidone (25 mg once a day), the two drugs combined at the same doses and the corresponding placebo. Compared with the randomly allocated placebo, the three active treatments significantly reduced blood pressure without changing the heart rate or body weight. Both the absolute and percentage decreases in mean blood pressure induced by nifedipine and the combination compared with placebo were similar and significantly greater than those induced by chlorthalidone. Taken together, these data show that the combination of nifedipine + chlorthalidone does not exert any additive antihypertensive effect compared with nifedipine alone. This finding indicates that the combination of a dihydropyridine calcium antagonist + a thiazide diuretic is probably devoid of any particular clinical significance in the treatment of uncomplicated essential hypertensives.

Adult

Randomised controlled trial of day and in-patient psychiatric treatment. 2: Comparison of two hospitals.

Acutely ill patients presenting for admission in two district psychiatric services were randomly allocated to day-hospital or in-patient care. In both services a quarter of all admissions could not be allocated because they were too ill (half of these were compulsory admissions); these patients were predominantly manic and schizophrenic patients with pronounced psychotic symptoms and disturbed behaviour. In one service 80% (41/51) of patients randomly allocated to day-hospital treatment were successfully engaged in treatment compared with 54% (19/35) in the other service. This difference arose because only patients with mildly disturbed behaviour could be treated at the second day hospital. For patients who were successfully allocated, the outcome of treatment was similar in terms of psychiatric symptoms and social functioning. The results of a treatment trial for acutely ill patients in one district service cannot be generalised to other district services without due attention to the factors, such as staffing levels, which determine the degree of disturbed behaviour that can be tolerated in the day hospital.

Acute Disease

A comparison of seven-point and visual analogue scales. Data from a randomized trial.

Many controlled trials rely on subjective measures of symptoms or quality of life as primary outcomes. The relative merits of different response options for these instruments is an important issue. Therefore, we compared the responsiveness and validity of seven-point versus visual analogue scales (VAS) in a questionnaire measuring quality of life in chronic heart failure in a double-masked crossover trial of digoxin versus placebo. The VAS and seven-point scale versions of the questionnaire were administered to 20 patients during 7 weeks on digoxin and 7 weeks on placebo. The order of administration of the questionnaires was determined by random allocation. The ability of the two methods to distinguish digoxin and placebo, and their correlation with other measures, were comparable. We conclude that the two methods of presenting response options show comparable responsiveness and validity in a randomized trial setting. The ease of administration and interpretation of the seven-point scale recommend its use.

Humans

UK Prospective Diabetes Study (UKPDS). VIII. Study design, progress and performance.

The UK Prospective Diabetes Study (UKPDS) is a multi-centre, prospective, randomised, intervention trial of 5100 newly-diagnosed patients with Type 2 (non-insulin-dependent) diabetes mellitus which aims to determine whether improved blood glucose control will prevent complications and reduce the associated morbidity and mortality. Newly presenting Type 2 diabetic patients aged 25-65 years inclusive, median age 53 years, median body mass index 28 kg/m2 and median fasting plasma glucose 11.3 mmol/l, were recruited and treated initially by diet. Ninety five percent remained hyperglycaemic (fasting plasma glucose greater than 6 mmol/l) and were randomly allocated to different therapies. In the main randomisation, those who were asymptomatic and had fasting plasma glucose under 15 mmol/l were allocated either to diet policy, or to active policy with either insulin or sulphonylurea aiming to reduce the fasting plasma glucose to under 6 mmol/l. Over 3 years, the median fasting plasma glucose in those allocated to diet policy was 8.9 mmol/l compared with 7.0 mmol/l in those allocated to active policy. The Hypertension in Diabetes Study has been included in a factorial design to assess whether improved blood pressure control will be advantageous. Patients with blood pressure greater than or equal to 160/90 mm Hg were randomly allocated to tight control aiming for less than 150/85 mm Hg with either an angiotensin-converting enzyme inhibitor or a Beta-blocker or to less tight control aiming for less than 200/105 mm Hg. The endpoints of the studies are major clinical events which affect the life and well-being of patients, such as heart attacks, angina, strokes, amputations, blindness and renal failure. To date, 728 patients have had at least one clinical endpoint. Surrogate endpoints include indices of macrovascular and microvascular disease detected by ECG with Minnesota Coding, retinal colour photography and microalbuminuria. The studies also aim to evaluate potential risk factors for the development of diabetic complications such as smoking, obesity, central adiposity, plasma LDL- and HDL-cholesterol, triglyceride, insulin, urate and other biochemical variables. The studies are planned to terminate in 1994, with a median follow-up of 9 years (range 3-16 years) for the glucose study and 5 years (range 2-6 years) for the hypertension study.

Adult

Evaluation of mezlocillin in elective gastrointestinal surgery.

We report the interim results of two trials to evaluate the place of mezlocillin in elective intestinal operations. Sixty-four operations for gastro-oesophageal disease have been performed where patients were randomly allocated to mezlocillin or cefuroxime. Wound sepsis occurred in 19% of the mezlocillin patients compared with 3% of those receiving cefuroxime. Seventy-three operations have been performed for colorectal cancer in whom three doses of antibiotic were used for prophylaxis. Patients were randomly allocated to mezlocillin and metronidazole or cefuroxime and metronidazole. The rates of abdominal wound sepsis in the groups were 15% and 12% respectively. Post-operative Clostridium difficile colitis occurred in four of the cefuroxime patients, compared with none of those receiving mezlocillin. Mezlocillin appears to be a safe and effective antibiotic when used in combination with metronidazole in colorectal resections for cancer.

Cefuroxime

Nurse-protocol management of low back pain. Outcomes, patient satisfaction and efficiency of primary care.

To test the validity of a nurse-administered protocol for low back pain, a prospective trial of 419 patients was undertaken in a walk-in clinic. In all, 222 patients were randomly allocated to a "nurse-protocol group" in which they were evaluated by one of five nurses using the protocol; the nurses independently managed 53 percent of the patients and referred to a physician patients with potentially complex conditions. In addition, 197 patients in a randomly allocated control group were managed by one of 32 physicians. Care in the experimental and control groups was compared by follow-up telephone contact and by a four-month chart review. There was no significant difference in symptomatic relief or the development of serious disease in the two groups. Nurse-protocol patients expressed greater satisfaction with the care they had received; patient satisfaction correlated positively with symptom relief. In over 95 percent of the patients, there were noncomplex, nonserious, nonchronic conditions as the cause of back pain. We conclude that nurse-protocol management of this generally benign condition in a primary care setting is both effective and efficient.

Adolescent

Neostigmine, pyridostigmine and edrophonium as antagonists of deep pancuronium blockade.

To compare the ability of equipotent doses of neostigmine, pyridostigmine and edrophonium to antagonize intense pancuronium neuromuscular blockade, one hundred and twenty ASA physical status I or II patients scheduled for elective surgery received 0.06 mg.kg-1 pancuronium during a thiopentone nitrous oxide-enflurane anaesthetic. Train-of-four stimulation was applied every 12 s and the force of contraction of the adductor pollicis muscle was recorded. In the first 60 patients, spontaneous recovery was allowed until ten per cent of initial first twitch height. Then neostigmine (0.005, 0.01, 0.02 or 0.05 mg.kg-1), pyridostigmine (0.02, 0.04, 0.1 or 0.2 mg.kg-1), or edrophonium (0.1, 0.2, 0.4 or 1 mg.kg-1) was injected by random allocation. Dose-response relationships were established from the measurement of first twitch height (T1) ten minutes later. From these, neostigmine, 0.04 and 0.08 mg.kg-1 was found to be equipotent to pyridostigmine, 0.2 and 0.38 mg.kg-1, and edrophonium, 0.54 and 1.15 mg.kg-1, respectively. These doses were given by random allocation to the next 60 patients, but at one per cent spontaneous recovery. Neostigmine, 0.04 mg.kg-1, produced a T1 of 73 +/- 4 per cent (mean +/- SEM), and a train-of-four ratio (TOF) of 39 +/- 3 per cent. This was significantly greater than with pyridostigmine, 0.2 mg.kg-1 (T1 = 50 +/- 6 per cent; TOF = 25 +/- 3 per cent), and edrophonium, 0.54 mg.kg-1 (T1 = 54 +/- 3 per cent; TOF = 17 +/- 2 per cent).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

A comparison of the efficacy and safety of ceftizoxime with doxycycline versus conventional CDC therapies in the treatment of upper genital tract infection with or without a mass.

It is well known that sexually transmitted infections of the upper genital tract are widespread. A variety of regimens are used to treat these conditions, many of which have not been subjected to randomized, prospective clinical trials (including the 1985 Centers for Disease Control [CDC] Guidelines for the treatment of upper genital tract infections [UGTI]). This investigation was undertaken to compare the 1985 CDC treatment guidelines with different doses of ceftizoxime, a third-generation cephalosporin with an intermediate half-life, plus doxycycline in patients with UGTI. The patients were divided into subgroups, depending on the presence or absence of a pelvic mass. Sixty-seven women participated in the study. They were older than 14 years of age and required hospitalization for the treatment of UGTI. These women had lower abdominal pain and tenderness, cervical motion or adnexal tenderness, and one of the following: temperature greater than 100.4 degrees F orally, leukocytosis greater than 10,500/mm3, or presence of a suspected inflammatory pelvic mass on pelvic examination or by ultrasound. Informed consent was obtained from all patients in a manner approved by the Institutional Review Board. Pelvic examinations and ultrasound evaluations of the pelvic soft tissues were performed on all patients at the time of admission. Those who were found not to have a pelvic mass or who had a pelvic mass less than 4 cm in transverse diameter were randomly allocated to receive either ceftizoxime 2 gm intravenously every 12 hours with doxycycline 100 mg intravenously twice daily (Rx 1, n = 13) or cefoxitin 2 gm intravenously every six hours with doxycycline 100 mg intravenously twice daily (Rx 2, n = 14). Those patients found to have a pelvic mass (greater than 4 cm in transverse diameter) were randomly allocated to receive either ceftizoxime 2 gm intravenously every eight hours with doxycycline 100 mg intravenously twice daily (Rx 3, n = 19) or clindamycin 900 mg intravenously every eight hours with a 2-mg/kg loading dose of gentamicin followed by 1.5 mg/kg intravenously every eight hours, with adjustments as necessary (Rx 4, n = 21). All UGTI patients without a mass treated with either Rx 1 or Rx 2 responded adequately. However, UGTI patients with a mass treated with Rx 4 were more likely than those treated with Rx 3 to require a change in antibiotics or need extirpative surgery in order to obtain a satisfactory clinical response (Fisher's exact test = 0.046, two-sided).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent

Effect of suture technique on early healing of intestinal anastomoses in rats.

OBJECTIVE: To see if the site and tension of sutures had any influence on early breaking strength in intestinal anastomoses. MATERIAL: 161 Male Wistar rats. INTERVENTIONS: First experiment: after laparotomy and division of the ileum an inverted end to end anastomosis was made in a single layer with 14 interrupted sutures of 7/0 polypropylene. All sutures were inserted 3 mm from the cut edges. The rats were randomly allocated to one of four groups according to the size of the loop of suture used: tight (n = 38), 0.4 mm (n = 22), 0.9 mm (n = 35), or 2.0 mm (n = 24). Second experiment: the method used was the same except that sutures were placed 1.5 mm from the cut edges and the rats were randomly allocated to one of two groups according to the size of loop of suture--tight (n = 20), or 0.9 mm (n = 22). MAIN OUTCOME MEASURES: Breaking strength measured in a tensiometer (both experiments); and myeloperoxidase activity/g tissue, hydroxyproline content and solubility/biopsy specimen (first experiment only). RESULTS: Breaking strength decreased proportionally the tighter the sutures were tied, and the differences were significantly greater when the sutures were placed closer to the cut edges. Anastomotic myeloperoxidase activity, hydroxyproline content, and soluble: total hydroxyproline ratio were similar in all groups. CONCLUSION: Tight sutures may promote proteolytic tissue degradation by reducing the local availability of circulating proteinase inhibitors.

Anastomosis, Surgical

A comparison of the effects of bisoprolol and atenolol on lipoprotein concentrations and blood pressure.

Forty-two patients (28 men, 14 women, age range 27-65 years) with newly discovered mild to moderate hypertension were randomly allocated to treatment with either bisoprolol or atenolol for a double-blind comparison of these two beta 1-adrenoceptor blocking drugs. Two doses of each drug (10 and 20 mg/d for bisoprolol and 50 and 100 mg/d for atenolol) were given, each dose for a 3-month period, the dose to be given first being decided by random allocation of the patients. During the second 3-month period, the patient received the alternative dose. After treatment for 6 and 12 weeks with each dose, the blood pressure, heart rate, and lipoprotein concentrations were checked. Bisoprolol treatment (both 10 and 20 mg) resulted in a decrease in blood pressure in the supine position from 154/100 to 138/89 mm Hg; and atenolol treatment resulted in decreases from 161/102 to 145/90 mm Hg (50 mg/d) and 146/91 mm Hg (100 mg/d). The drugs and doses did not differ in their effect. The triglyceride content in very low density lipoproteins (VLDL) increased during treatment with bisoprolol (10 mg/d) from 1.04 to 1.31 mmol/l (p less than 0.05); during treatment with atenolol (100 mg/d) it increased from 0.90 to 1.14 mmol/l (p less than 0.05). The cholesterol content in low density lipoproteins did not change, but that in high density lipoproteins (HDL) decreased during treatment with both drugs (from 1.22 to 1.10 mmol/l with bisoprolol 20 mg/d, p less than 0.01: and from 1.21 to 1.13 mmol/l with atenolol 100 mg/d, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists

Pilonidal sinus: a claim for simple track incision.

Ninety-six patients treated surgically for pilonidal sinus were examined in a two-part study. In the first part, 36 patients were randomly allocated according to the surgical techniques employed: marsupialization, incision, and excision without primary closure. Healing times and recurrences a year after operation were studied. The healing times of patients treated by excision were longer in comparison with those treated by incision or marsupialization. The recurrence rates were similar for all techniques used. In the second part of the study 60 patients were randomly allocated according to times of returning to work. Twenty-nine of these patients returned to work before their wound healed; 31 resumed work a week after epithelization of the wound. The wounds healed more quickly in patients who started working before they were closed. Incision of the sinus track, carried out using local anesthesia in the outpatient clinic, allowed the patient to return to work without pain sooner.

Anesthesia, Local

A two-stage trial design for testing treatment, self-selection and treatment preference effects.

We propose a two-stage randomized clinical trial design for separating treatment effects from those resulting from choosing treatment. At the first stage all patients are randomly allocated to one of two groups, the random group and the option group. At the second stage, patients in the random group are randomized a second time to treatment A or B, whereas patients in the option group are given a free choice between the two treatments. If there are differences in treatment response between the random group and the option group, there are two potential sources of bias: self-selection by choosing treatment, and effects of suggestion by receiving the preferred treatment. A linear model is presented to estimate these effects separately along with test statistics which are approximately normally distributed.

Clinical Trials as Topic

Treatment of atopic dermatitis with antihistamines: lessons from a single-patient, randomized clinical trial.

BACKGROUND: Single-patient randomized clinical trials (RCTs) can be utilized to maintain methodologic precision in the analysis of treatment effect in individual patients. We describe the results of a single-patient RCT in a patient with atopic dermatitis and review practical considerations regarding the use of antihistamines. METHODS: Using double-blind, crossover techniques, the patient was randomly allocated to four 2-week treatment periods with the following regimens: chlorpheniramine, 8 mg twice daily; chlorpheniramine, 12 mg twice daily; terfenadine, 120 mg twice daily; and placebo (phase 1). The drug that produced superior results from phase 1 (chlorpheniramine, 8 mg) was subsequently compared with astemizole, 10 mg/d, during phase 2, consisting of four 4-week, double-blind, crossover trial periods with random allocation of study drugs. Daily symptom scores, as well as end of treatment period summary impressions by patient and investigator, were analyzed. RESULTS: In both phases, chlorpheniramine produced the most noticeable positive therapeutic effect on the patient's mild but most disturbing symptoms (pruritus and eye irritation) associated with atopic dermatitis. Drowsiness was reported with chlorpheniramine. Tolerance to this side effect, however, developed quickly. CONCLUSIONS: A single-patient RCT with different antihistamines in a patient with chronic atopic dermatitis was a useful tool in achieving a favorable balance among efficacy, toxicity, and cost of therapy.

Adult

Influence of humoral and volume factors on altered osmoregulation of normal human pregnancy.

These studies were designed to characterize mechanisms leading to decreased plasma osmolality (Posmol) and osmotic thresholds (T) for arginine vasopressin (AVP) release (TAVP) and thirst (Tthirst) in pregnancy. First, the influence of the pregnancy hormone, human chorionic gonadotrophin (hCG), was tested in six nonpregnant women who received hypertonic saline during the luteal phase of the menstrual cycle on two occasions (randomly allocated), once after 15,000 IU of hCG when Posmol, TAVP, and Tthirst decreased 6, 5, and 5 mosmol/kgH2O, respectively (P less than 0.01). In contrast, hCG pretreatment of males (n = 6) had no significant effect. Next, the role of decreased effective vascular volume (underfilling) was evaluated in seven women undergoing hypertonic saline infusion in the presence and absence of head-out water immersion (randomly allocated) during early and late pregnancy and postpartum. Posmol, TAVP, and Tthirst were not influenced by immersion and remained 10 mosmol/kgH2O lower in pregnancy (P less than 0.01). Central redistribution of intravascular volume consistently lowered hematocrit and rate of rise of PAVP per unit increment in Posmol (P less than 0.01). Although these data failed to support the hypothesis that the osmoregulatory change in human pregnancy is attributable to decrements in effective central volume (underfill), they do suggest that hCG may play a role.

Adult