Life-history plasticity in female threespine stickleback

The postglacial adaptive radiation of the threespine stickleback fish (Gasterosteus aculeatus) has been widely used to investigate the roles of both adaptive evolution and plasticity in behavioral and morphological divergence from the ancestral condition represented by present-day oceanic stickleback. These phenotypes tend to exhibit high levels of ecotypic differentiation. Population divergence in life history has also been well studied, but in contrast to behavior and morphology, the extent and importance of plasticity has been much less well studied. In this review, we summarize what is known about life-history plasticity in female threespine stickleback, considering four traits intimately associated with reproductive output: age/size at maturation, level of reproductive effort, egg size and clutch size. We envision life-history plasticity in an iterative, ontogenetic framework, in which females may express plasticity repeatedly across each of several time frames. We contrast the results of laboratory and field studies because, for most traits, these approaches give somewhat different answers. We provide ideas on what the cues might be for observed plasticity in each trait and, when possible, we inquire about the relative costs and benefits to expressed plasticity. We end with an example of how we think plasticity may play out in stickleback life history given what we know of plasticity in the ancestor.

[Primary and re-arthroplasty of the hip or knee joints in patients 80 years of age and older]

Due to the ageing of the population, more and more patients older than 80 years are in need of the hip and knee joints total endoprosthesis. The aim of this retrospective study was to describe perioperative mortality and frequency of complications associated with both primary and re-arthroplasty of hip and knee joints in this age group. For more information about demography, the perioperational period and frequency of complications were investigated 59 patient's card, who have had a 71 endoprosthesis operations, carried out by one surgeon. Information on mortality was obtained by means of telephone interviewing. The average level of mortality within 30 days, 1 year and 5 years amounted to 2.0, 6.1 and 10.2% respectively. Compared with other studies conducted over the past 20 years, these results reflect a significant reduction in the mortality, rate. Average frequency of complications in our study was to 52.2%. which corresponds to the previously published data. All the complications were eliminated and did not cause permanent disability. Thanks to the development of anaesthesia, surgical techniques and technologies, joint endoprosthetics can be considered safe in patients older than 80 years.

Patterns and prevalence of disordered eating and weight control behaviors in women ages 25-45

OBJECTIVE

The current study describes detailed eating behaviors, dieting behaviors, and attitudes about shape and weight in 4023 women ages 25 to 45.

METHOD

The survey was delivered on-line and participants were identified using a national quota-sampling procedure.

RESULTS

Disordered eating behaviors, extreme weight loss measures, and negative cognitions about shape and weight were widely endorsed by women in this age group and were not limited to White participants. Thirty-one percent of women without a history of anorexia nervosa or binge eating reported having purged to control weight, and 74.5% of women reported that their concerns about shape and weight interfered with their happiness.

DISCUSSION

Unhealthy approaches to weight control and negative attitudes about shape and weight are pervasive even among women without eating disorders. The development of effective approaches to address the impact of these unhealthy behaviors and attitudes on the general well-being and functioning of women is required.

Corticosteroid-induced osteoporosis in children: outcome after two-year follow-up, risk factors, densitometric predictive cut-off values for vertebral fractures

OBJECTIVE

To identify factors that contribute to a decreased Z score of volumetric spine bone mineral density (ZvSBMD) and the development of vertebral fractures (VF) in children receiving chronic systemic corticosteroid therapy (SCT); to describe their outcome after 2 years, and to define predictive threshold values for ZvSBMD for VF.

METHODS

Fifty-five children on SCT for >or= 6 months were prospectively followed for 2 years. In children with a ZvSBMD > -1.5, we prescribed preventive measures for osteoporosis and densitometry annually. In children with ZvSBMD <or= -1.5, we prescribed spine x-rays and those with VF received alendronate. The association between clinical and biochemical variables and the presence of VF or ZvSBMD were analyzed by logistic regression or multiple regression analysis. The threshold value of ZvSBMD for predicting VF was determined by ROC curve and the probability of having a VF was modeled by multiple logistic regressions.

RESULTS

Children who do not develop osteoporosis at first evaluation tend to maintain normal ZvSBMD after two years. Alendronate increased ZvSBM (median: at baseline: -2.69; 1 yr: -1.92; 2 years: -1.39, p < 0.001). The threshold value of ZvSBMD for predicting VF was -1.8. In this cohort, the risk of developing VF was significantly higher in children who were not ambulatory, growth retarded, treated with methotrexate for a longer time, had a family history of osteoporosis or were of non-aboriginal ancestry.

CONCLUSION

Children on SCT, who do not develop osteoporosis, tend to maintain normal BMD. Children who were not ambulatory, on methotrexate or growth retarded have higher rates of VF.

Influence of prenatal cocaine exposure on full-term infant neurobehavioral functioning

This study investigated infant neurobehavioral functioning during the newborn period in 334 full-term, African American neonates (187 cocaine exposed, 147 non-cocaine exposed) enrolled prospectively at birth, with documentation of drug exposure status through maternal interview and urine and meconium toxicology assays. Infants were assessed using the Brazelton Neonatal Behavioral Assessment Scale (BNBAS) during the newborn period (0-6 postnatal days). Findings from multivariate profile analyses support a consistent, modest effect of prenatal cocaine exposure on neurobehavioral functioning in full-term neonates. All of the BNBAS cluster scores, with the exception of abnormal reflexes, were similarly affected, sharing a common slope (D=-0.14; 95% CI=-0.27, -0.003; P=.046) representing a -0.14 point difference between cocaine-exposed and non-cocaine-exposed infants after controlling for prenatal exposure to alcohol, tobacco, and marijuana (ATM); maternal age, education, employment, primigravida status, and prenatal care visits; and infant sex and postnatal age in days. Fetal growth was also related to neurobehavioral functioning and, in part, mediated the relationship between cocaine exposure and the BNBAS cluster scores. Cocaine exposure during each trimester similarly influenced infant neurobehavioral profiles, with cocaine-associated deficits most pronounced in infants with exposure in all three trimesters. Results from qualitative and quantitative urine and meconium bioassay indicators further substantiated these results. Findings, while significant, represent modest effect sizes in full-term infants.

[Measurement of 17 OH progesterone in blood in Chilean newborns: antecedents for implementing a grogram for the neonatal detection of congenital adrenal hyperplasia]

BACKGROUND

The early diagnosis and therapy of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency can prevent adrenal crises and erroneous gender assignment in affected newborns. To achieve this goal neonatal mass-screening programs have been developed, measuring blood 17 alpha-hydroxyprogesterone (17OHP). In Chile there is no experience with this type of screening.

AIM

To develop a method for measuring 17OHP in filter paper blood specimens. To obtain reference ranges and determine neonatal 17OHP threshold levels according to gestational age and birth weight. To analyze factors affecting the cost-efficiency ratio and suggest recommendations for the organization of a neonatal screening program for CAH in Chile.

MATERIAL AND METHODS

Nine hundred twenty two newborns were studied. 17OHP was measured using double antibody radioimmunoassay in filter paper blood samples obtained 48 h after birth. Reference ranges were determined according to gestational age and birth weight and a cutoff point of 25 ng/ml was established.

RESULTS

Seventeen newborns had 17OHP over the cutoff value. They were assessed by a pediatric endocrinologist and in none of them, CAH was confirmed. Therefore the false positive rate of the determination was 1.8%. Among these newborns with elevated 17OHP, 66% had a birth weight below 1.5 kg and 5.8%, a birth weight between 1.5 and 2.5 kg. The cost per reported result was US $ 1. Timing of the recall was between the 3 and 10 days of life. No newborn missed the follow-up.

DISCUSSION

To increase the cost-efficiency ratio of an eventual neonatal screening program, newborns with birth weights below 1.5 kg should be excluded and cutoff points should be defined according to birth weight (Rev Méd Chile 2000; 128: 1113-18).

Association of sunlight exposure and photoprotection measures with clinical outcome in systemic lupus erythematosus

This study was designed to explore the relationship of sunlight exposure and ultraviolet (UV) light protection measures with clinical outcome in systemic lupus erythematosus (SLE). A structured questionnaire was administered to sixty Puerto Rican SLE patients, to assess their attitudes and behavior regarding sunlight exposure and photoprotection measures. Medical records were reviewed to evaluate the clinical outcome measures that included: clinical manifestations, number of SLE-related hospitalizations, number of exacerbations and pharmacologic treatment. Almost all (98.3%) patients were well acquainted of sunlight effects on disease activity. Two thirds were exposed to direct sunlight for an average of less than one hour per day and 33.3% for one hour or more. Thirty patients (50%) reported use of sunscreen, with sun protective factor of 15 or greater, when exposed to sunlight. Less than 40% of patients regularly wore hat or long-sleeves clothes to protect from sunlight. Although there were some clinical differences between the groups with different sunlight exposure times, none reached statistical significance. Also, no significant differences were found between the groups in regards to sunlight protective clothes. However, patients that regularly used sunscreen had significantly lower renal involvement (13.3 vs 43.3%), thrombocytopenia (13.3 vs 40%), hospitalizations (26.7 vs. 76.7%), and requirement of cyclophosphamide treatment (6.7 vs. 30%) than patients that did not used it (P < 0.05). We conclude that use of sunscreen photoprotection was associated with a better clinical outcome in our SLE patients. These findings further support the importance and benefits of photoprotective measures in patients with SLE.

Electromyographic analysis of the shoulder muscles during depression transfers in subjects with low-level paraplegia

OBJECTIVE

To document and compare the intensity of selected shoulder muscle activity during depression transfers.

DESIGN

Intramuscular electrodes were used to record the activity of 12 shoulder muscles while transferring to and from a wheelchair.

PARTICIPANTS

Twelve adult men with spinal cord injuries resulting in low paraplegia.

OUTCOME MEASURES

Three phases of the transfer were analyzed: preparation, lift, and descent. Median intensities were compared between muscles, transfer phase, and direction of transfer using Freidman's test.

RESULTS

Trunk elevation was accomplished mainly by sternal pectoralis major and latissimus dorsi activity. Lateral body displacement required other muscles to control the elevated body. Rotator cuff muscles contributed to shift mechanics and, together with anterior deltoid, provided anterior glenohumeral wall protection. Lower serratus anterior stabilized the scapulothoracic articulation and contributed to the lateral movement.

CONCLUSIONS

Assessment of depression transfer skill should not be based on the ability to lift body weight. Movement of the trunk required vigorous activity of key shoulder musculature. Differences in leading and trailing arm EMG intensities will assist in modifying transfer style in individuals with weakness, strength imbalances, and shoulder pathologies.

Electromyographic analysis of shoulder muscles of men with low-level paraplegia during a weight relief raise

The purpose of this study was to define the demand on the shoulder musculature during performance of a weight relief raise. Intramuscular electromyographic activity of 12 shoulder muscles was recorded in 13 pain-free subjects with paraplegia while elevating the trunk from a sitting position. Upper extremity motion was determined by elbow electrogoniometry and video recordings. Three phases of the raise were analyzed: initial loading, lift, and hold. During the lift phase, high level triceps long head activity (54% manual muscle test [MMT]) produced elbow extension, whereas moderate- to high-level activity of the sternal pectoralis major (32% MMT) and latissimus dorsi (58% MMT) elevated the trunk on the fixed humerus. Deltoid, supraspinatus, infraspinatus, subscapularis, middle trapezius, serratus anterior, and biceps long head played minimal roles (< 25% MMT). Thoracohumeral muscle activity, by transferring the load on the humerus directly to the trunk, functionally circumvented the glenohumeral joint. This would reduce the potential for impingement of the rotator cuff.