Corticosterone levels of Atlantic puffins vary with breeding stage and sex but are not elevated in poor foraging years

Corticosterone (CORT) levels in seabirds fluctuate across breeding stages and in different foraging conditions. Here we use a ten-year data set to examine whether CORT levels in Atlantic puffins differ in years with high or low availability of capelin, the preferred forage species. Female puffins had higher CORT levels than males, possibly related to cumulative costs of egg production and higher parental investment. Puffins had higher CORT levels and body mass during pre-breeding than during chick rearing. Yearly mean chick growth rates were higher in years when adults had higher body mass and in years where adults brought chicks a lower percentage of non-fish (invertebrates/larval fish) food. Unlike most results from seabird species with shorter chick-rearing periods, higher CORT levels in puffins were not associated with lower capelin abundance. Puffins may suppress CORT levels to conserve energy in case foraging conditions improve later in the prolonged chick-rearing period. Alternatively, CORT levels may be lowest both when food is very abundant (years not in our sample) or very scarce (e.g., 2009 in this study), and increase when extra foraging effort will increase foraging efficiency (most years in this study). If these data primarily represent years with medium to poor foraging, it is possible that CORT responses to variation in foraging conditions are similar for puffins and other seabirds.

Cross section dependence of event rates at neutrino telescopes

We examine the dependence of event rates at neutrino telescopes on the neutrino-nucleon cross section for neutrinos with energy above 1 PeV, and contrast the results with those for cosmic ray experiments. Scaling of the standard model cross sections leaves the rate of upward events essentially unchanged. Details, such as detector depth and cross section inelasticity, can influence rates. Numerical estimates of upward shower, muon, and tau event rates in the IceCube detector confirm these results.

Masked hypertension: a common but insidious presentation of hypertension

A patient has masked hypertension when his office blood pressure is less than 140/90 mmHg but his ambulatory or home blood pressure readings are in the hypertensive range. Several recent studies have demonstrated that cardiovascular risk is similar between those with masked hypertension and those with sustained hypertension. The prevalence of masked hypertension in Canada is not known, but data from other countries suggest rates greater than 8%. Physicians need to use careful clinical judgment to identify and treat subjects with masked hypertension. The present review discusses masked hypertension, its importance to clinical practice and some aspects of patient management.

The 2000 Canadian recommendations for the management of hypertension: part two--diagnosis and assessment of people with high blood pressure

OBJECTIVE

To provide updated, evidence-based recommendations for the diagnosis and assessment of high blood pressure in adults.

OPTIONS

For people with high blood pressure, the assignment of a diagnosis of hypertension depends on the appropriate measurement of blood pressure, the level of the blood pressure elevation, the duration of follow-up and the presence of concomitant vascular risk factors, target organ damage and established atherosclerotic diseases. For people diagnosed with hypertension, defining the overall risk of adverse cardiovascular outcomes requires laboratory testing, a search for target organ damage and an assessment of the modifiable causes of hypertension. Out-of-clinic blood pressure assessment and echocardiography are options for selected patients.

OUTCOMES

People at increased risk of adverse cardiovascular outcomes and were identified and quantified.

EVIDENCE

Medline searches were conducted from the period of the last revision of the Canadian recommendations for the management of hypertension (May 1998 to October 2000). Reference lists were scanned, experts were polled, and the personal files of the subgroup members and authors were used to identify other studies. All relevant articles were reviewed and appraised, using prespecified levels of evidence, by content experts and methodological experts.

VALUES

A high value was placed on the identification of people at increased risk of cardiovascular morbidity and mortality.

BENEFITS, HARMS AND COSTS

The identification of people at higher risk of cardiovascular disease will permit counselling for lifestyle manoeuvres and the introduction of antihypertensive drugs to reduce blood pressure for patients with sustained hypertension. In certain settings, and for specific classes of drugs, blood pressure lowering has been associated with reduced cardiovascular morbidity and/or mortality.

RECOMMENDATIONS

The present document contains detailed recommendations pertaining to aspects of the diagnosis and assessment of patients with hypertension, including the accurate measurement of blood pressure, criteria for the diagnosis of hypertension and recommendations for follow-up, routine and optional laboratory testing, assessment for renovascular hypertension, home and ambulatory blood pressure monitoring, and the role of echocardiography in hypertension.

VALIDATION

All recommendations were graded according to strength of the evidence and voted on by the Canadian Hypertension Recommendations Working Group. Only the recommendations achieving high levels of consensus are reported here. These guidelines will be updated annually.

ENDORSEMENT

These recommendations are endorsed by the Canadian Hypertension Society, The Canadian Coalition for High Blood Pressure Prevention and Control, The College of Family Physicians of Canada, The Heart and Stroke Foundation of Canada, The Adult Disease Division and Bureau of Cardio-Respiratory Diseases and Diabetes at the Centre for Chronic Disease Prevention and Control of Health Canada.

Self-measurement of blood pressure: accuracy, patient preparation for readings, technique and equipment

OBJECTIVE

Self-measurement of blood pressure is commonly performed by those persons with hypertension and is advocated in many national hypertension guidelines. We examined accuracy of readings, patient knowledge, and preparation for readings, technique and equipment.

DESIGN

The study was a prospective observational design. Sixty-nine hypertensive patients were recruited from a tertiary referral center and by newspaper advertisement. All patients had previously self-measured their blood pressure. The patients initially measured their blood pressure under direct supervision in a clinic using their usual preparation, technique and their own equipment. Then after a five-min rest, blood pressures were measured twice both by research nurse and the patient in an alternating sequence. The nurse used a standardized blood pressure measurement technique.

RESULTS

Inadequate patient knowledge and performance of measurement technique and inaccurate equipment was common. The average initial patient systolic reading prior to the five-minute rest was higher than that of the trained nurse (9.1 +/- 13 mmHg systolic, p < 0.001 and 1.5 +/- 8.0 mmHg diastolic, p = 0.12). Almost half (42%) of the initial patient blood pressure readings differed in classification of hypertension/normotension from the nurse. The difference between the patient and nurse readings after the five-min rest was 3.8 +/- 11.8 / 1.1 +/- 6.8 mmHg.

CONCLUSIONS

Care must be taken in interpreting patient self-measured blood pressure unless there has been adequate training and assessment of patient and equipment accuracy. Studies of health care professionals reveal similar problems therefore widespread efforts to standardize blood pressure measurement are necessary.

Lifestyle modifications to prevent and control hypertension. 3. Recommendations on alcohol consumption. Canadian Hypertension Society, Canadian Coalition for High Blood Pressure Prevention and Control, Laboratory Centre for Disease Control at Health Canada, Heart and Stroke Foundation of Canada

OBJECTIVE

To provide updated, evidence-based recommendations concerning the effects of alcohol consumption on the prevention and control of hypertension in otherwise healthy adults (except pregnant women).

OPTIONS

There are 2 main options for those at risk for hypertension: avert the condition by limiting alcohol consumption or by using other nonpharmacologic methods, or maintain or increase the risk of hypertension by making no change in alcohol consumption. The options for those who already have hypertension include decreasing alcohol consumption or using another nonpharmacologic method to reduce hypertension; commencing, continuing or intensifying antihypertensive medication; or taking no action and remaining at increased risk of cardiovascular disease.

OUTCOMES

The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered.

EVIDENCE

A MEDLINE search was conducted for the period 1966-1996 with the terms ethyl alcohol and hypertension. Other relevant evidence was obtained from the reference lists of articles identified, from the personal files of the authors and through contacts with experts. The articles were reviewed, classified according to study design, and graded according to the level of evidence.

VALUES

A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension.

BENEFITS, HARMS AND COSTS

A reduction in alcohol consumption from more than 2 standard drinks per day reduces the blood pressure of both hypertensive and normotensive people. The lowest overall mortality rates in observational studies were associated with drinking habits that were within these guidelines. Side effects and costs were not measured in any of the studies.

RECOMMENDATIONS

(1) It is recommended that health care professionals determine how much alcohol their patients consume. (2) To reduce blood pressure in the population at large, it is recommended that alcohol consumption be in accordance with Canadian low-risk drinking guidelines (i.e., healthy adults who choose to drink should limit alcohol consumption to 2 or fewer standard drinks per day, with consumption not exceeding 14 standard drinks per week for men and 9 standard drinks per week for women). (3) Hypertensive patients should also be advised to limit alcohol consumption to the levels set out in the Canadian low-risk drinking guidelines.

VALIDATION

These recommendations are similar to those of the World Hypertension League, the National High Blood Pressure Education Program Working Group on Primary Prevention of Hypertension and the previous recommendations of the Canadian Coalition for High Blood Pressure Prevention and Control and the Canadian Hypertension Society. They have not been clinically tested. The low-risk drinking guidelines are those of the Addiction Research Foundation of Ontario and the Canadian Centre on Substance Abuse.

SPONSORS

The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at Health Canada, and the Heart and Stroke Foundation of Canada. The low-risk drinking guidelines have been endorsed by the College of Family Physicians of Canada and several provincial organizations.

Is usual measurement of blood pressure meaningful?

BACKGROUND

Standardized measurement of blood pressure is widely recommended but rarely applied in usual clinical practice.

OBJECTIVE

To determine the differences resulting from physicians using standardized and usual (casual) techniques for measurement of blood pressure.

METHODS

Blood pressures measured by a research nurse, ambulatory blood pressure monitoring and echocardiographic estimation of left ventricular mass index were used as standards for comparison.

RESULTS

Use of casual technique resulted in blood pressure readings higher than those obtained by standardized technique, namely 6.2 (3.1-9.3) systolic and 3.9 (2.4-5.4) diastolic mmHg [means (95% confidence intervals)], and readings that were more variable. Sixty-two patients (42%) were classified normotensive by standardized techniques but hypertensive by physicians casual technique. When standardized technique was used 22 patients (15%) were classified hypertensive but blood pressure readings in normal range were obtained by usual technique. Measurements obtained using standardized technique were less variable and were significantly correlated to left ventricular mass index.

CONCLUSION

Using standardized technique is important if one is to classify the blood pressures of patients correctly. Use of usual or casual technique results in higher, more variable readings that are not related to left ventricular mass index. Results of this study strongly support recommendations that standardized technique should be used for assessing the cardiovascular risk of all adult patients.

Are Women Underrepresented as Authors and Editors of Educational Psychology Journals?

To determine the progress women have made in the last 20 years in terms of contributions to the knowledge base (i.e., authorship) and reputations as leading contributors (i.e., appointments as editors and editorial board members) in educational psychology, we analyzed data from six journals: the American Educational Research Journal, Contemporary Educational Psychology, the Educational Psychologist, Educational Psychology Review, the Journal of Experimental Education, and the Journal of Educational Psychology. Results indicated that (a) women's progress in terms of authorships could be predicted by their increasing representation as educational psychologists, (b) opportunities for females to become editorial board members seem to be getting better, and (c) opportunities for females to become editors seem to be getting worse. Copyright 1998 Academic Press.

Dislocation of hip in myelomeningocele. The McKay hip stabilization

We reviewed the clinical and radiographic results of varus osteotomy of the proximal aspect of the femur and transfer of the adductor and external oblique muscles (the McKay procedure) in thirty-four children (sixty-six hips) who had an unstable hip secondary to a myelomeningocele at the middle or caudad lumbar level. the average age at the time of the operation was twenty months (range, seven to forty-two months). The average duration of follow-up was 10.9 years (range, 0.7 to 20.0 years). An open reduction was performed in ten hips. None of the children had had any previous operative treatment. The index operation helped to maintain the stability of thirty-seven of the fifty-one hips twenty-six children who remained neurologically stable: seventeen of nineteen hips that were at risk, two of three hips with acetabular dysplasia, fifteen of sixteen subluxated hips, one of three dislocated hips that had been previously reduced with a Pavlik harness, one of two dislocatable hips, and one of seven previously untreated dislocated hips. The index operation was not successful for one dislocated hip that had been treated with closed reduction and application of a spica cast. The operation was a success for eight of the fifteen hips in eight children who had a progressive loss of neurological function: three of five hips that were at risk, one hip with acetabular dysplasia, two of four subluxated hips, one of two that had been previously reduced with a Pavlik harness, and one dislocatable hip. Two dislocated hips redislocated. Initially the index operation was performed on all children who had a myelomeningocele at the third or fourth lumbar level. Recent data have shown that the hips in these children are not all at risk, and we now perform the operation only if there is documented instability of the hip.

Self-measurement of blood pressure: assessment of equipment. Canadian Coalition for High Blood Pressure Prevention and Control

Equipment for the self-measurement of blood pressure is readily available to consumers. These devices use one or more surrogate (indirect) measures of pressure to estimate systolic and diastolic blood pressure. Manual auscultatory devices using stethoscope and sphygmomanometer have been adapted for home use, but a variety of automated devices based on auscultation, oscillometry, and other techniques are available and may be more suitable for individuals who have limited vision, hearing or dexterity. Despite the existence of voluntary evaluation protocols and mandatory manufacturing standards, blood pressure readings from some automatic devices may not be accurate. Some devices are packaged with insufficient information to ensure proper use, and most individuals need some form of guidance in their use and calibration testing. If self-measurement of blood pressure is to be of benefit, the health care professional must recommend only those devices that are accurate and suitable to the patient or client. The Canadian Coalition for High Blood Pressure Prevention and Control will endeavour to develop a regular means by which health care professionals can keep informed of available devices for blood pressure self-measurement.

Self-measurement of blood pressure: recommendations of the Canadian Coalition for High Blood Pressure Prevention and Control

OBJECTIVE

To provide health care professionals with guidelines on the use of blood pressure self-measurement.

METHODS

Recommendations were devised after consideration of expert reviews and guidelines, personal files, international standards documents, personal communication with investigators and the results of a MEDLINE search (1966-94) using the term 'blood pressure determination'.

BENEFITS, HARMS, COSTS

Self-measurement of blood pressure can be used to detect white coat hypertension, monitor changes in blood pressure closely, more rapidly achieve desired blood pressure goals, increase adherence to antihypertensive therapy and improve patient self-reliance. However, self-measured blood pressure readings may be misleading because there is insufficient normative, prognostic and outcome data and because some patients may not take accurate measurements. The use of self-measurement of blood pressure has a relatively small direct cost and may result in an overall reduction in treatment costs.

RECOMMENDATIONS

Self-measured blood pressure readings can be a valuable supplement to clinic (or office) blood pressure readings. However, self-measurement is appropriate neither for patients who are physically or mentally incapable of accurate assessment and interpretation of readings nor for those who do not want to participate. Patients who self-monitor blood pressure require careful training in blood pressure measurement and instruction on the recording and interpretation of blood pressure readings. Advice to patients using monitoring equipment must take into account the needs and abilities of the patient. Although only a few electronic devices for the self-measurement of blood pressure have met recommended performance standards, their use may be more appropriate for some patients and the training requirements fewer than if manual devices are used.

VALIDATION

The guidelines of several expert groups were examined in the preparation of these recommendations. The recommendations were presented at the World Conference on Hypertension Control in 1995 and were reviewed by the parent societies of the Canadian Coalition for High Blood Pressure Prevention and Control.

Medroxyprogesterone increases basal temperature: a placebo-controlled crossover trial in postmenopausal women

OBJECTIVE

To assess whether temperature is increased by medroxyprogesterone (MPA) and thus whether basal temperature records could be used to determine ovulation during cyclic MPA therapy.

DESIGN

A 2-month double-blind placebo-controlled crossover trial in which oral basal temperature was measured daily.

SETTING

Normal human volunteers in an academic medical environment.

SUBJECTS

Eleven postmenopausal women not taking gonadal hormones.

INTERVENTION

Medroxyprogesterone acetate (10 mg/d) or placebo, calendar days 16 to 25, with crossover.

MAIN OUTCOME MEASURES

Comparison of mean temperature days 17 to 26 during MPA versus placebo; comparison of differences between temperatures days 7 to 16 and 17 to 26 in MPA versus placebo months; and analysis for a significant monthly thermal shift.

RESULTS

The mean temperatures during MPA treatment averaged 0.27 degrees C higher than during the placebo phase and showed a significant change from pretreatment to "treatment" phases during MPA but not during placebo cycles. Eight of the MPA and one of the placebo cycles showed a shift from lower to higher temperatures days 16 to 25.

CONCLUSIONS

Medroxyprogesterone acetate has a physiological progesterone-like thermal effect. Therefore basal temperature data cannot reliably indicate ovulation during cyclic MPA administration.

Errors in assessment of blood pressure: blood pressure measuring technique

This article reviews the recommended techniques for accurate and reproducible blood pressure measurements. The scientific basis underlying current recommendations for blood pressure measurement is presented. Many of the current recommendations are not followed in ambulatory care clinics and this paper will show how measurement errors in excess of 15 mm Hg or more can occur. Many patients will be misclassified and treated inappropriately when errors in blood pressure measurement of this magnitude are made. Rigorous adherence to proper blood pressure measurement is necessary to evaluate a patient's risk of cardiovascular disease, and to assess the need or efficacy of antihypertensive therapy.

Pitfalls to avoid in the measurement of blood pressure in the elderly

Accurate, reproducible blood pressure readings are more difficult to obtain in the elderly. Elderly patients have more variable blood pressure, show a reduction in blood pressure following meals, and can have postural hypotension, discrepancies in blood pressure between arms, auscultatory gaps and 'pseudohypertension', all of which can mislead clinicians regarding these patients' usual blood pressure. Arrhythmias, particularly atrial fibrillation, make accurate blood pressure determination difficult and are more common in the elderly. Prostatic hypertrophy causing high pressure urinary retention is suggested as a common and reversible cause of hypertension in older men. Proper measurement of blood pressure in elderly patients demands additional thought and action, all of which are necessary for accurate cardiovascular risk assessment and proper therapeutic decisions. Increasing the number of visits and the number of carefully taken blood pressure readings per visit will result in a more accurate assessment of blood pressure in older patients.

Errors in assessment of blood pressure: sphygmomanometers and blood pressure cuffs

This article reviews the current recommendations on equipment when blood pressure is measured by sphygmomanometer. The scientific rationale underlying the current recommendations for selection and maintenance of blood pressure measuring equipment is presented. The errors that can occur when the recommendations are not followed are quantified whenever the data are available. Inadequate assessment and maintenance of equipment often lead to the use of faulty equipment, and as a result errors in the assessment of patients' blood pressure are likely to be common. If followed, the current guidelines for use and maintenance of equipment would remove most of the problems noted. Physicians must ensure that properly maintained and appropriate equipment is used to measure blood pressure.

Errors in assessment of blood pressure: patient factors

This article reviews patient-related factors affecting blood pressure measurement and provides the scientific rationale underlying current recommendations for the measurement of blood pressure in the evaluation of hypertension. Information is included on the magnitude of errors that can occur when the recommendations are not followed. A variety of factors relating to the patient's emotions, activity, bodily function and environment cause blood pressure to fluctuate throughout the day such that peak systolic and diastolic blood pressures are often twice as high as trough levels. Many physicians fail to account for these factors when assessing a patient's blood pressure. Errors in the classification and treatment of a patient's blood pressure and the finding of labile blood pressure can occur often when patients are not adequately prepared in advance of the blood pressure measurement.

Percutaneous intramedullary fixation of long bone deformity in severe osteogenesis imperfecta

Reported here are seven patients who had severe osteogenesis imperfecta, and who were extremely fragile, with three having cardiac disease. Their age ranged between 8 and 35 months. All seven patients had unbraceable deformities. Twenty five long bones, including 14 tibiae, 10 femora, and 1 ulna underwent percutaneous intramedullary fixation. Four patients had all four lower extremity long bones operated on simultaneously. Followup was 2 to 11 years. There were no neurologic or vascular complications, compartment syndromes, growth plate problems, or transfusion requirements. All bones healed. One patient had migration of a femoral pin into the knee joint. After bracing, all patients were able to sit; five were able to stand and eventually walk. All living patients were able to be sustained until successful definitive long bone fixation could be accomplished, approximately 2 years or longer after this initial procedure. With this safe, reproducible method, early stable fixation can be provided to patients too young and/or too sick for definitive or extensive open surgery. Future treatment regimens are not compromised.

The antianginal efficacy of isosorbide dinitrate therapy is maintained during diuretic treatment

OBJECTIVES

To determine whether the use of a diuretic would maintain the antianginal efficacy of isosorbide dinitrate during 1 week of therapy.

METHODS

During continuous therapy, organic nitrates have a reduction in antianginal effectiveness and cause fluid retention. The study was a randomized, double-blind, placebo-controlled crossover design examining the effect of 1 week of daily treatment with 50 mg hydrochlorothiazide/5 mg amiloride on the antianginal effectiveness of 30 mg isosorbide dinitrate administered every 6 hours. Exercise stress testing was performed before and 3 hours after administration of isosorbide dinitrate at the start and end of the placebo and diuretic treatment phases.

RESULTS

The time to onset of angina (475 +/- 35 versus 490 +/- 29 seconds, difference not significant) and to moderate angina after administration of isosorbide dinitrate (542 +/- 40 versus 566 +/- 37 seconds, difference not significant) were similar at the start and end of the diuretic phase of the study but were reduced at the end of the placebo phase (471 +/- 40 versus 410 +/- 40 seconds, p < 0.05 and 531 +/- 38 versus 466 +/- 39 seconds, p < 0.05, respectively). Total exercise time and time to onset of angina 3 hours after administration of isosorbide dinitrate were longer (p < 0.005) at the end of the diuretic phase compared with the end of the placebo phase. Patients gained weight during the placebo phase and lost weight during the diuretic phase of the study. The change in weight was inversely correlated to the change in total exercise time (r = -0.53, p < 0.05).

CONCLUSIONS

Patients using a diuretic with isosorbide dinitrate maintain an increased anginal threshold and total exercise time compared with placebo. Weight change is inversely related to exercise duration, and this result is consistent with fluid retention restoring cardiac preload during nitrate use. The increased anginal threshold during concurrent isosorbide dinitrate and diuretic use may be attributable to maintenance of the organic nitrate-induced reductions in cardiac preload.

No adverse effects of medroxyprogesterone treatment without estrogen in postmenopausal women: double-blind, placebo-controlled, crossover trial

OBJECTIVE

To determine whether cyclic medroxyprogesterone treatment given without estrogen causes adverse symptoms in postmenopausal women.

METHODS

This was a placebo-controlled, double-blind, crossover trial of 10 days/month of medroxyprogesterone and placebo treatments given during 2 consecutive months in random order. Participants recorded their physiologic and emotional experiences on a 0-4 scale using a daily diary form. Eleven postmenopausal women aged 43-63 completed the study. The subjects were not taking hormones. Height, weight, and serum estradiol concentration were measured once. In each woman, the sum of scores for the 10 days of medroxyprogesterone was compared to the sum of scores for the 10 days of placebo using nonparametric tests.

RESULTS

No significant differences in scores were found between the 10 days on medroxyprogesterone and the 10 days on placebo. The median and range for the composite scores for premenstrual-like symptoms were 26 (20-67) during medroxyprogesterone and 25 (19-40) during placebo (P = .39).

CONCLUSIONS

Medroxyprogesterone given alone does not cause adverse symptoms in postmenopausal women. Therefore, medroxyprogesterone therapy, by itself, cannot explain the side effects reported by postmenopausal women taking combined hormones.

Alteration in gastrointestinal peptides after thermal injury in humans

Alterations in gastrointestinal function are common after thermal injury in humans. The peptide hormones gastrin and cholecystokinin are known to exert effects on gastric and biliary motility and on secretory function and to induce trophic changes in gut mucosa. The effect of injury on these hormones has received little attention. Six patients with burns were studied while receiving a combination of regular diet and continuous enteral feeding. Four healthy members of the nursing staff served as the control group. Blood was drawn every 4 hours for 24 hours. Gastrin and cholecystokinin were analyzed by radioimmunoassay. Patients with burns demonstrated significantly higher levels of gastrin and lower levels of cholecystokinin when compared with the control group. Patients with burns also failed to demonstrate the normal circadian variation in these peptides.

Exocrine pancreatic function in obstructive jaundice rats: studies with isolated dispersed pancreatic acini

This study was conducted to investigate pancreatic exocrine function and pancreatic growth in rats with obstructive jaundice (OJ). OJ was produced in adult male Sprague-Dawley rats by bile duct ligation; control rats underwent laparotomy only. Induction of OJ was associated with significant hyperplasia and hypertrophy of the pancreas in rats as shown by increased DNA and RNA contents of pancreatic tissue. Factors associated with pancreatic growth in OJ rats were further examined in isolated dispersed pancreatic acini from OJ rats and the data were compared with those for control rats. Studies with isolated dispersed acini from OJ rats showed that pancreatic growth was accompanied by significant increases in total cellular amylase content; however, amylase release (percentage of initial) in response to cholecystokinin octapeptide was significantly decreased in OJ rats compared to control rats. Total amylase output in response to 100 pM cholecystokinin (CCK) was higher in the OJ group when compared to the control group (8.6 U/mg protein versus 6.4 U/mg protein), as calculated from the total amylase content and percentage of amylase released. Receptor binding data showed that the capacity of CCK receptors in OJ rats was significantly lower when it was compared with control. In addition, plasma levels of CCK were significantly elevated in OJ rats when compared to controls. These results suggest that obstructive jaundice induces pancreatic growth that is associated with alteration of exocrine pancreatic function. Abnormally high levels of stored amylase in pancreatic acini may be implicated in the development of pancreatitis as often seen in obstructive jaundice patients.

Reproduction for the athletic woman. New understandings of physiology and management

A physically active and athletic lifestyle is not only a healthy but a fulfilling choice for women. Although there is extensive literature on 'athletic amenorrhoea' which implies that exercise causes loss of the menstrual cycle, there is inadequate scientific evidence for a causal relationship. The reproductive system adapts to environmental, nutritional, emotional and physical stressors or 'threats' by downward adjustment towards the premenarcheal pattern. The hormonal milieu of this adaptation is low gonadal steroid and high glucocorticoid levels which synergistically increase the risk for a negative bone balance. Athletic women may become amenorrhoeic if reproductive immaturity, emotional stress and undernutrition coexist with increasing exercise loads. Treatment for athletic women with menstrual cycle changes requires that hypothalamic stressors be identified and decreased. In addition, as progesterone deficiency (from disorders of ovulation, whether flow is regular or absent) is the most prevalent menstrual cycle change, treatment with medroxyprogesterone on days 16 to 25 of their cycle will not only provide regular flow (if estrogen levels are sufficient) but will also promote increased bone density.

Norfloxacin interaction with antacids and minerals

The urinary excretion of norfloxacin was measured in eight healthy volunteers after its co-administration with a variety of over-the-counter preparations, each containing a different metal ion. Commonly used doses of ferrous sulphate, zinc sulphate, aluminium hydroxide and magnesium hydroxide reduced the 24 h urinary excretion of norfloxacin by 50 to 90%. Bismuth subsalicylate had no significant effect. In vitro experiments demonstrated the formation of complexes between norfloxacin and iron, zinc, aluminium, and magnesium ions, respectively. Many pharmaceuticals contain the same metal ions that caused significant interactions with norfloxacin. The efficacy of norfloxacin treatment may be compromised when it is taken concurrently with preparations containing these metal ions.

Clinical and chemical interactions between iron preparations and ciprofloxacin

1. The effect of ferrous sulphate (300 mg), ferrous gluconate (600 mg), and a combination tablet of iron (10 mg), magnesium (100 mg), zinc (15 mg), calcium (162 mg), copper (2 mg), and manganese (5 mg) (Centrum Forte) co-administration on ciprofloxacin bioavailability was tested in eight healthy subjects. 2. Peak serum ciprofloxacin concentrations and area under the curve (AUC) were significantly reduced when ciprofloxacin was administered with 300 mg ferrous sulphate (3.0 vs 2.0 mg l-1, P less than 0.05 and 12.3 vs 6.7 mg l-1 h, P less than 0.01, respectively). Reductions in peak ciprofloxacin concentrations and AUC also occurred when ciprofloxacin was ingested with 600 mg ferrous gluconate (1.3 mg l-1, P less than 0.01 and 4.1 mg l-1 h, P less than 0.01, respectively) and a Centrum Forte tablet (1.4 mg l-1, P less than 0.01 and 5.4 mg l-1 h, P less than 0.01, respectively). 3. When ferrous ion was mixed with ciprofloxacin, rapid spectral changes occurred (t1/2 = 1.9 min). Additional studies were consistent with oxidation of the ferrous form of iron to its ferric form, which is followed by rapid formation of a Fe(3+)-ciprofloxacin complex. Ciprofloxacin seems to bind to ferric ion in a ratio of 3:1 by interacting with the 4-keto and 3-carboxyl groups on ciprofloxacin. 4. The formation of a ferric ion-ciprofloxacin complex is probably the cause of the reduction in ciprofloxacin bioavailability in the presence of iron.

Clinical assessment of blood pressure

This study was performed to determine the blood pressure measuring techniques and accuracy of sphygmomanometers used by physicians in ambulatory care clinics on the Avalon Peninsula of Newfoundland. Of the 114 participating physicians, no physician completely followed all the recommended BP measuring techniques of the American Heart Association. Almost all physicians supported the patient's arm at heart level to measure BP. Fewer physicians used the following recommended techniques; palpation to initially assess systolic BP (38%), measurement of BP in both arms (23%), an appropriate rate of cuff deflation (18%), measurement of BP in recommended patient positions (10%), the appropriate length of rest (4%) or use of a cuff of appropriate size (3%). Approximately 8% of mercury sphygmomanometers were out of calibration by at least 4 mmHg but none were out by more than 6 mmHg. Forty percent of aneroid sphygmomanometers were out of calibration by at least 4 mmHg and of these 30% were out by 10 mmHg or more. Mercury and aneroid sphygmomanometers were used by 60% of physicians. Aneroid sphygmomanometers were used exclusively by 34% of physicians, while 5% of physicians relied solely on mercury devices. Standardized techniques for BP measurement are not used and inaccurate sphygmomanometers are common; these factors may lead to misclassification of blood pressure and inappropriate treatment of patients.

Accurate, reproducible measurement of blood pressure

The diagnosis of mild hypertension and the treatment of hypertension require accurate measurement of blood pressure. Blood pressure readings are altered by various factors that influence the patient, the techniques used and the accuracy of the sphygmomanometer. The variability of readings can be reduced if informed patients prepare in advance by emptying their bladder and bowel, by avoiding over-the-counter vasoactive drugs the day of measurement and by avoiding exposure to cold, caffeine consumption, smoking and physical exertion within half an hour before measurement. The use of standardized techniques to measure blood pressure will help to avoid large systematic errors. Poor technique can account for differences in readings of more than 15 mm Hg and ultimately misdiagnosis. Most of the recommended procedures are simple and, when routinely incorporated into clinical practice, require little additional time. The equipment must be appropriate and in good condition. Physicians should have a suitable selection of cuff sizes readily available; the use of the correct cuff size is essential to minimize systematic errors in blood pressure measurement. Semiannual calibration of aneroid sphygmomanometers and annual inspection of mercury sphygmomanometers and blood pressure cuffs are recommended. We review the methods recommended for measuring blood pressure and discuss the factors known to produce large differences in blood pressure readings.

Comparative behavioral, neurochemical and pharmacological activities of dihydropyridine calcium channel activating drugs

The behavioral (deficits in motor function in mice), neurochemical (affinity for mouse brain membrane dihydropyridine receptors, effects on neurotransmitter/metabolite levels in mice) and pharmacologic (effect on the contractile activity of guinea pig ileal longitudinal smooth muscle) properties of the calcium channel activators (+/-)-BAY K 8644, (+/-)-202-791 (and their corresponding channel activating and antagonist enantiomers) and CGP-28392 were investigated and compared. The calcium channel activating enantiomers (-)-S-BAY K 8644, (+)-S-202-791 and (+/-)-BAY K 8644, (+/-)-202-791 and CGP-28392 produced a dose-dependent impairment of rotarod ability and decreases in motor activity in mice with the following order of potency: (-)-S-BAY K 8644 greater than (+/-)-BAY K 8644 much greater than (+)-S-202-791 greater than (+/-)-202-791 = CGP-28392. The calcium channel antagonists (+)-R-BAY K 8644 and (-)-R-202-791 were behaviorally inactive but blocked the behavioral effects of (-)-S-BAY K 8644. The binding of dihydropyridine calcium channel activator and antagonist enantiomers to mouse brain membranes was described by both one and two site models. (-)-S-BAY K 8644, (+/-)-BAY K 8644, (+)-S-202-791 and CGP-28392 produced contractions in partially depolarized (15 mM K+) strips of guinea pig ileal longitudinal smooth muscle which differed in the degree of maximum contraction obtained. (+)-R-BAY K 8644 and (-)-R-202-791 inhibited potassium-induced contractions (80 mM K+) in guinea pig ileal longitudinal smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral angiotensin II stimulates release of vasotocin in conscious chickens

In mammals, intracranial or peripheral administration of angiotensin II (ANG II) has a number of actions, including the release of antidiuretic hormone (ADH). Relatively little is known of the interactions between the renin-angiotensin and ADH systems in birds. In the present study [Asp1, Val5]ANG II (fowl ANG II) was infused intravenously into conscious White Leghorn cockerels to determine whether peripheral ANG II influences the release of arginine vasotocin (AVT), the avian ADH. Cannulas were inserted into a wing artery and vein under local anesthesia. ANG II was dissolved in 0.154 M NaCl and administered intravenously at 0, 2, 20, and 200 ng X kg-1 X min-1. In a second series of experiments, ANG II was infused in 0.1 and 1.0 M NaCl (200 ng X kg-1 X min-1) to examine the effect of the peptide on osmotic release of ADH. In the three groups administered ANG II in 0.154 M NaCl, plasma AVT before intravenous infusion averaged between 1.8 +/- 0.46 to 2.6 +/- 0.30 microU/ml. In these birds, infusion of ANG II at 2, 20, and 200 ng X kg-1 X min-1 caused plasma AVT to increase over preinfusion means by 39, 78, and 300%, respectively. The changes in AVT occurred in the absence of differences in plasma osmolality, electrolyte composition, or arterial blood pressure among the groups. In chickens that were administered ANG II in 0.1 and 1.0 M NaCl, significantly higher plasma AVT levels were observed compared with a control group receiving the saline infusions alone.(ABSTRACT TRUNCATED AT 250 WORDS)

An antiserum that recognizes mesotocin and isotocin: development of a homologous radioimmunoassay for plasma mesotocin in chickens (Gallus domesticus)

This report presents characteristics of an antiserum raised in a rabbit immunized with synthetic mesotocin (MT) conjugated to bovine thyroglobulin. Cross-reactivity studies indicate that the antiserum (Kl-II) recognizes the carboxyl-terminal "tail" of MT and isotocin (IT). A homologous, disequilibrium radioimmunoassay (RIA) for MT has been developed that can detect less than 1 pg of peptide. Plasma was extracted with octadecasilyl-silica. Recovery of MT from plasma was correlated with the amount added and averaged 70%. Different volumes of plasma and posterior pituitary extract, when measured in the assay system, yielded inhibition curves that were parallel with standard MT. Immunoreactive MT and AVT of plasma and neural lobe coeluted with synthetic standards after gel filtration. The ED50 of a heterologous, sequential saturation RIA for IT was 17.4 pg, suggesting that the MT antiserum may be useful for measuring the oxytocin-like principle in bony fishes. Immunoreactive MT in plasma of cockerels increased and decreased with iv infusion of hypo- and hyperosmotic saline, respectively. The changes in plasma MT were inversely related to osmolality. Hyperosmotic saline infusion resulted in correlated increases in plasma AVT and osmolality. The data suggest that MT may be released by dilution and/or expansion of extracellular fluid in chickens.

Comparative effects of the neurotoxins N-chloroethyl-N-ethyl-2-bromobenzylamine hydrochloride (DSP4) and 6-hydroxydopamine on hypothalamic noradrenergic, dopaminergic and 5-hydroxytryptaminergic neurons in the male rat

The intracerebroventricular (i.c.v.) administration of 6-hydroxydopamine (6-OHDA; 50 micrograms X 3) and the systemic administration of DSP4 (50 mg/kg X 2; i.p.), alone and in combination, were compared for their abilities to alter the concentrations of norepinephrine (NE), dopamine (DA), dihydroxyphenylacetic acid (DOPAC) and 5-hydroxytryptamine (5-HT) in selected hypothalamic and extra-hypothalamic (striatum, frontal cortex, hippocampus) regions of the male rat brain. DSP4 markedly lowered NE concentrations in extrahypothalamic regions, and within the hypothalamus produced a mild and variable reduction of NE without altering concentrations of DA, DOPAC or 5-HT. 6-OHDA markedly lowered NE concentrations in all brain regions, but was without effect on DA, DOPAC and 5-HT concentrations in any region analyzed. Combined treatment with DSP4 and 6-OHDA did not produce additional effects on levels of NE, DA and DOPAC over either drug alone, but did cause a mild reduction of 5-HT in several brain regions. These results indicate that systemic treatments with DSP4 per se are not as effective as i.c.v. 6-OHDA in depleting NE in the hypothalamus, and that when the two neurotoxins are administered there appears to be some destruction of 5-HT neurons.