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.

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 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.

Malignant hyperthermia and central core disease in a child with congenital dislocating hips.

We describe a development of a malignant hyperthermia (MH) syndrome, partially aborted by therapy, in a child with central core disease and congenital dislocating hips. Patients with central core disease appear to be more susceptible to MH; possibly those with elevated serum creatine phosphokinase levels, as in our patient, are especially susceptible. We review the clinical and pathologic aspects, possible pathogenesis, and treatment of the MH syndrome. An increased calcium level within the muscle fiber is suggested as the major cytodestructive factor, and that increase could be consequent to a plasmalemmal susceptibility to the provoking drugs hypothesized to be the basic defect in MH. Prevention of the full manifestations of MH is predicated on (1) a high index of suspicion in the search for history of anesthetic complications in the patient and his family, with or without evident neuromuscular disease, (2) recognition that there is a somewhat greater risk of MH developing in a patient who has certain "musculoskeletal" abnormalities or muscle weakness but that is not-except for central core disease-a classic clinicopathologically defined disease, (3) close monitoring of patients during anesthesia, and (4) if the syndrome develops, prompt therapeutic measures, including cessation of anesthesia.

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.

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.

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.

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.

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.

Estrogens influence cholecystokinin stimulated pancreatic amylase release and acinar cell membrane cholecystokinin receptors in rat.

This study examines the influence of ovariectomy and administration of a pharmacologic dose of estradiol on amylase release from isolated-dispersed rat pancreatic acini and cholecystokinin receptors on rat acinar cell membranes. Rats were sham ovariectomized (intact) or ovariectomized (Ovx) and 21 day timed release pellets containing either estradiol (2.5 mg) or vehicle, were implanted subcutaneously. Eighteen days later, pancreatic acini were isolated from rats by collagenase digestion and differential centrifugation. Total cellular amylase, basal and cholecystokinin octapeptide (CCK8) stimulated amylase release and CCK membrane receptors were measured. Acini isolated from estradiol treated Ovx rats had significantly greater total cellular amylase, compared to acini isolated from either intact or Ovx rats. The amplitude of both total stimulated amylase release and percent total stimulated amylase release were significantly greater for acini isolated from vehicle treated Ovx rats, than acini isolated from either intact or estradiol treated Ovx rats. The magnitude of percent total amylase release of acini isolated from estradiol treated Ovx rats was significantly lower than that of acini isolated from intact rats. Cholecystokinin receptor concentration was significantly greater on membranes prepared from vehicle treated Ovx rats, compared to membranes prepared from either intact or estradiol treated Ovx rats. These data indicate that ovariectomy is associated with increased responsiveness of pancreatic acini to CCK stimulation, while chronic estradiol treatment of ovariectomized rats is associated with increased total cellular amylase and decreased acinar cell responsiveness to CCK8. Estrogen mediated alterations in acinar cell amylase content and amylase release may play a role in estrogen related pancreatitis.

Dorsal bunions in children.

Iatrogenic dorsal bunions in children, observed mostly after operations for post-poliomyelitic paralysis or club foot, have been successfully treated by an operation in which the tendons of the flexor brevis and the abductor and adductor muscles of the hallux are transferred to the neck of the first metatarsal. This is supplemented by removal of the sesamoids, capsulotomy of the metatarsophalangeal joint, and when necessary by arthrodesis or tenodesis of the metatarsophalangeal joint. In seventeen feet treated in this way only one failure, in a patient with arthrogryposis, was recorded.

Treatment of unicameral bone cysts by subtotal resection without grafts.

Twenty-one patients were treated operatively for unicameral bone cysts by subtotal resection without any form of bone graft, and all but two patients had satisfactory, prompt healing. The rate of recurrence was 9%. Five patients were noted to have humeral shortening prior to any surgery, and in them the changes in the epiphyseal cartilage were noted preoperatively. Pathological fractures were thought to be the cause of the shortening in those cases.

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.

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.

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.

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.

Cheilectomy of the hip.

Cheilectomy is an excellent procedure for salvaging decompensated hips in childred aged 10 to 14 years when certain indicators are present: coxa magna and plana, a completely ossified epiphysis, an open physis, and a well preserved cartilage space. Accurate assessment in these cases is extremely important, since a combination of surgical procedures may be necessary. The cheilectomy will correct deformities of the femoral head only; if inadequacies exist in the acetabulum, a pelvic osteotomy must be performedwhile transfer of the greater trochanter is required when the trochanter exhibits cephalad movement or the femoral neck is short. Postoperative treatment is the most critical element of the process, requiring careful and thorough evaluation of results and immediate attention to any loss in the patient's range of motion. Although the relative newness of the procedure presently makes impossible any claims about its permanent efficacy, follow-up reports in patients who have undergone the surgery indicate that the cheilectomy can yield long term beneficial results. And in the decompensated hip, even if the problems are alleviated for only a 10 to 15 year period, the surgery has been worthwhile.

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.