Hypothalamic-pituitary dysfunction after radiation for brain tumors

BACKGROUND

Patients with brain tumors who are treated with radiation frequently have growth hormone deficiency, but other neuroendocrine abnormalities are presumed to be uncommon.

METHODS

We studied endocrine function in 32 patients (age, 6 to 65 years) 2 to 13 years after they had received cranial radiotherapy for brain tumors. The doses of radiation to the hypothalamic-pituitary region ranged from 3960 to 7020 rad (39.6 to 70.2 Gy). Nine patients also received 1800 to 3960 rad (18.0 to 39.6 Gy) to the craniospinal axis. Serum concentrations of thyroid, gonadal, and pituitary hormones were measured at base line and after stimulation.

RESULTS

Nine patients (28 percent) had symptoms of thyroid deficiency, and 20 patients (62 percent) had low serum total or free thyroxine or total triiodothyronine concentrations. Of the 23 patients treated only with cranial radiation, 15 (65 percent) had hypothalamic or pituitary hypothyroidism. Of the nine patients who also received spinal (and thus direct thyroid) radiation, three (33 percent) had evidence of primary thyroid injury. Seven of the 10 postpubertal, premenopausal women (70 percent) had oligomenorrhea, and 5 (50 percent) had low serum estradiol concentrations. Three of the 10 men (30 percent) had low serum testosterone concentrations. Overall, 14 of the 23 postpubertal patients (61 percent) had evidence of hypogonadism. Mild hyperprolactinemia was present in 50 percent of the patients. Responses to stimulation with corticotropin-releasing hormone and corticotropin were normal in all patients except one, who had panhypothalamic dysfunction. However, serum 11-deoxycortisol responses to the administration of metyrapone were low in 11 of the 31 patients (35 percent) tested. Three of the 32 patients, (9 percent) had no endocrine abnormalities, 9 (28 percent) had an abnormal result on tests of thyroid, gonadal, prolactin, or adrenal function, 8 (25 percent) had abnormalities in two axes, 8 (25 percent) in three axes, and 4 (12 percent) in all four axes.

CONCLUSIONS

Cranial radiotherapy in children and adults with brain tumors frequently causes abnormal hypothalamic-pituitary function. The most frequent changes are hypothyroidism and gonadal dysfunction, although subtle abnormalities in adrenal function may also be present.

Role of cytomegalovirus in the T cell changes seen in elderly individuals

The effect of prior cytomegalovirus (CMV) infection on the immune system was evaluated in young and elderly volunteers. Prevalence of IgG antibodies to CMV was higher in the elderly volunteers. In both age groups, there was a strong association with CMV seropositivity and increased number of CD28- CD4 or CD8 T cells, as well as with increased numbers of T cells expressing CD56 or DR. Although these changes have previously been reported to be age-related, they were independent of age when CMV serological status was taken into account. In contrast, both age group and CMV status were important determinants of the total number of T cells, the number of CD8 T cells, and the number of CD8 T cells expressing CD45RA or CD28. These findings indicate that prior infection with CMV, as reflected by CMV serological status, has important effects on T cell subsets and surface markers and must be considered whenever evaluating age-related changes in immunological parameters.

Effects of cocoa extracts on endothelium-dependent relaxation

The aim of this study was to examine the effects of procyanidins derived from cocoa on vascular smooth muscle. Two hypotheses were tested: 1) extracts of cocoa, which are rich in procyanidins, cause endothelium-dependent relaxation (EDR), and 2) extracts of cocoa activate endothelial nitric oxide synthase (NOS). The experiments were carried out on aortic rings obtained from New Zealand White rabbits. The polymeric procyanidins (tetramer through decamer of catechin) caused an EDR. In addition, the Ca(2+)-dependent NOS activity, measured by the L-arginine to L-citrulline conversion assay, was significantly increased in aortic endothelial cells exposed to polymeric procyanidins, whereas monomeric compounds had no such effect. These findings demonstrate that polymeric procyanidins cause an EDR that is mediated by activation of NOS.

Sustained growth and three-dimensional organization of primary mammary tumor epithelial cells embedded in collagen gels

We have developed a method for embedding cells within a collagen matrix which allows sustained growth of mouse mammary tumor epithelial cells in primary culture. A characteristic and reproducible pattern of organization and growth occurs: the cells rearrange themselves and produce duct-like structures extending into the matrix, resulting in a three-dimensional outgrowth. Autoradiography showed continuous [3H]thymidine incorporation during 8 weeks in culture. An increase in DNA content of the cultured cells as a function of time was observed. Mouse mammary tumor cells cultured in the conventional monolayer system failed to show any significant increase in cell number during a culture period of 6 weeks. In addition, in such monolayer systems, cells progressively became detached from the dishes in long-term culture. The mammary epithelial cell origin of the collagen gel cell outgrowths was shown by electron microscopic demonstration of polarized cells containing tight junctions and budding mammary tumor virus particles. In addition, in vivo transplantation of collagen gel outgrowths resulted in the development of mammary adenocarcinoma histologically similar to the donor tumor. Cellular outgrowth patterns resembling those from tumor cells were also seen in similar collagen gel cultures of normal mammary cells from mouse and human and of hyperplastic alveolar nodule cells from mouse. The significance and usefulness of this system in comparison to the conventional monolayer system are discussed.

Effects of aerobic exercise training on cognitive function and cortical vascularity in monkeys

This study examined whether regular exercise training, at a level that would be recommended for middle-aged people interested in improving fitness could lead to improved cognitive performance and increased blood flow to the brain in another primate species. Adult female cynomolgus monkeys were trained to run on treadmills for 1 h a day, 5 days a week, for a 5 month period (n=16; 1.9+/-0.4 miles/day). A sedentary control group sat daily on immobile treadmills (n=8). Half of the runners had an additional sedentary period for 3 months at the end of the exercise period (n=8). In all groups, half of the monkeys were middle-aged (10-12 years old) and half were more mature (15-17 years old). Starting the fifth week of exercise training, monkeys underwent cognitive testing using the Wisconsin General Testing Apparatus (WGTA). Regardless of age, the exercising group learned to use the WGTA significantly faster (4.6+/-3.4 days) compared to controls (8.3+/-4.8 days; P=0.05). At the end of 5 months of running monkeys showed increased fitness, and the vascular volume fraction in the motor cortex in mature adult running monkeys was increased significantly compared to controls (P=0.029). However, increased vascular volume did not remain apparent after a 3-month sedentary period. These findings indicate that the level of exercise associated with improved fitness in middle-aged humans is sufficient to increase both the rate of learning and blood flow to the cerebral cortex, at least during the period of regular exercise.

Growth factor- and cyclic nucleotide-induced proliferation of normal and malignant mammary epithelial cells in primary culture

Sustained growth of normal mouse mammary epithelial cells in primary culture, leading to an increase in cell number, in response to growth factors [epidermal growth factor (EGF) and fibroblast growth factor (FGF)] or cholera toxin has been achieved by embedding the cells inside collagen cells. Inclusion of agents known to increase the level of cellular cAMP have been found to be favorable for mammary epithelial cell proliferation. Cholera toxin is by far the best of all of the agents tested (prostaglandins E1 and E2, isoproterenol, theophylline, and dibutyryl cAMP). When growth factors (EGF or FGF) are added with cholera toxin, a synergistic effect resulting in a response much greater than with either of them alone is seen. This synergism was best seen in normal mammary epithelial cells from nonpregnant mice. The extent of this synergistic effect was found to be less in normal cells from pregnant mice, suggesting that these cells may be less responsive to EGF during pregnancy. Tumor cells were found to be rather inconsistent in their responses to EGF and cholera toxin, ranging from a minimal response, similar to that of normal cells from pregnant animals, to a maximal response, similar to that of normal cells from nonpregnant animals.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Bipolar surface electrical stimulation of the vertebrate retina

BACKGROUND

Retinitis pigmentosa with attendant photoreceptor loss can cause a profound visual handicap. We have postulated that an intraocular prosthesis that could electrically stimulate the inner retina might provide vision to some of these patients. For such a prosthesis to be feasible, electrical stimulation of the inner retina must elicit a focal retinal response. The stimulating current densities required to elicit such a response must not result in irreversible toxic reactions at the electrode-tissue interface.

METHODS

To test the feasibility of this approach, we used bipolar platinum wire electrodes to electrically stimulate the inner retinal surface in bullfrog eyecup preparations and, using similar methods, we electrically stimulated rabbit eyes after injecting intravenous sodium iodate (40 mg/kg), a retinal pigment epithelial toxin with secondary effects on the photoreceptors.

RESULTS

Surface electrical stimulation of the inner retina in normal eyes and in eyes with outer retinal degeneration can elicit a localized retinal response. The threshold stimulating currents resulted in charge densities of 2.98 microcoulombs per square centimeter (bullfrog), 8.92 microC/cm2 (normal rabbit), and 11.9 microC/cm2 (rabbit retinas with outer retinal degenerations). These charge densities are within the previously delineated safe limits for long-term electrical stimulation of neural tissue using platinum microelectrodes (100 microC/cm2).

CONCLUSION

Multifocal electrical stimulation of the retina might be a viable approach to provide some vision to patients who have profound visual loss due to outer retinal degenerations.

Feeding preterm infants after hospital discharge: effect of dietary manipulation on nutrient intake and growth

The objective of this study was to compare formula intake, the time of weaning, and growth in preterm infants (< or = 1750-g birth weight, < or = 34-wk gestation) fed a standard term or preterm infant formula after initial hospital discharge. Infants were randomized at hospital discharge to be fed a preterm infant formula from discharge to 6 mo corrected age (group A), a term formula from discharge to 6 mo (group B), or the preterm formula (discharge to term) and the term formula (term to 6 mo (group C). Infants were seen biweekly (discharge to term) and monthly (term to 6 mo), when intake was measured and anthropometry and blood sampling were performed. The results were analyzed using ANOVA. Although nutrient intake was similar, at 6 mo girls were lighter (6829 versus 7280 g) and shorter (64.4 versus 66.0 cm) than boys (p < 0.05). Patient characteristics were similar between the treatment groups. Although the volume of intake differed (B > C > A; p < 0.001), energy intake was similar in the groups. Because of differences in formula composition, protein, calcium, and phosphorus intakes differed (B < C < A; p < 0.001). Lower protein intakes were related to lower blood urea nitrogen levels (B < C < A; p < 0.001). At 6 mo, infant boys in B and C were lighter (6933, 6660 < 7949 g), shorter (65.3, 64.9 < 67.1 cm), and had a smaller head circumference (43.7, 43.7 < 44.8 cm; p < 0.05) than infants in group A. Preterm infants were found to increase their volume of intake to compensate for differences in energy density between formulas. After hospital discharge, infant boys fed a preterm formula grew faster than infant girls fed a preterm formula or infant boys fed a term formula.

Mitomycin C-augumented trabeculectomy with postoperative wound modulation in pediatric glaucoma

PURPOSE

The purpose of this study was to evaluate mitomycin C-augmented trabeculectomy combined with postoperative subconjunctival 5-fluorouracil and laser suture lysis in the treatment of refractory pediatric glaucoma.

METHODS

Twenty-one consecutive cases (17 patients) with refractory pediatric glaucoma treated with mitomycin C trabeculectomy (0.4 mg/mL for 3 to 5 minutes) and postoperative 5-fluorouracil, laser suture lysis, or both were retrospectively reviewed. Success was defined as intraocular pressure between 4 and 16 mm Hg without further glaucoma surgery or devastating complication.

RESULTS

The median age of the study population was 2.6 years (range, 0.05 to 16 years). The overall success rate was 52.4%, with a median follow-up of 23 months for successful cases. Success rates for patients older than 1 year of age versus those younger than 1 year of age at surgery were 73% and 30%, respectively. Success rates for phakic versus aphakic eyes were 64% and 29%, respectively. Age and lens status, taken together, were significant predictors of outcome (P = .013). Reasons for failure in this study were uncontrolled intraocular pressure (8 cases), persistent wound leak (1 case), and endophthalmitis (1 case); the latter 2 cases required bleb excision. Other complications encountered included chorioretinal detachment, shallow anterior chamber, 5-fluorouracil toxicity, and cataract formation. No irreversible visual deficits could be attributed to the trabeculectomy procedure or subsequent complications in any of these cases.

CONCLUSIONS

Mitomycin C-augmented trabeculectomy combined with postoperative suture lysis and 5-fluorouracil is a viable option for older phakic children with refractory glaucoma. This procedure has a lower success rate in infants and in aphakic eyes. Both early and late postoperative complications are common, and diligent lifelong long-term follow-up is needed to detect bleb leaks and infection. The addition of postoperative suture lysis and 5-fluorouracil to mitomycin C-augmented trabeculectomy did not provide any convincing improvement in the success of this procedure in pediatric patients with refractory glaucoma and may have increased the complication rate.

Pharmacokinetics of anticonvulsants in pregnancy: alterations in plasma protein binding

Anticonvulsant levels decline as pregnancy progresses, even in the face of constant and, in some cases, increased dosages of medications. It has been suggested that this decline is responsible for the increase in seizure frequency seen in approximately one-third of the women with epilepsy who become pregnant. Changes in plasma protein binding may explain the declines in anticonvulsant concentrations during pregnancy. A prospective cohort study was designed to test this hypothesis. Carbamazepine, phenytoin and phenobarbital were studied. The mean total concentrations of all 3 drugs declined as pregnancy progressed, rising in the postpartum period. Free concentrations also declined, but did so significantly only for phenobarbital. The free fraction for all anticonvulsants studied rose significantly throughout pregnancy. Protein binding is significantly altered during pregnancy for all 3 drugs studied and appears to account for much of the decline in anticonvulsant concentrations seen in this condition. It is suggested that free rather than total drug concentrations be monitored in pregnant women with epilepsy.

Multimodality management of recurrent adult malignant gliomas: results of a phase II multiagent chemotherapy study and analysis of cytoreductive surgery

Fifty-one adult patients with recurrent malignant gliomas were treated in a Phase II trial of multidrug chemotherapy (6-thioguanine, dibromodulcitol, procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, 5-fluorouracil, and hydroxyurea). Thirty-one patients underwent radical tumor debulking, before the administration of chemotherapy. Fifty-seven percent of all patients had either an objective radiographic response or stabilization of disease after the institution of therapy. The overall median survival time (MST) was 40 weeks; it was 79 and 33 weeks for anaplastic astrocytoma and glioblastoma patients, respectively. The overall median time to tumor progression (MTP) was 19 weeks--32 weeks for anaplastic astrocytoma patients and 13 weeks for glioblastoma patients. Serious chemotoxicity occurred in 35% of patients without permanent morbidity or mortality. The factors that affected response (including disease stabilization), MTP, and MST were identified through a multivariate statistical analysis. A longer MTP was associated with higher Karnofsky scores, lower grade initial histology, lack of prior chemotherapy, greater degree of myelotoxicity, smaller postoperative tumor volumes, greater extent of surgical resection, and a local versus diffuse recurrence pattern. A longer MST was associated with higher Karnofsky scores, lower grade histology at the time of recurrence, greater degree of myelotoxicity, and lobar versus deep tumor location. Response (including disease stabilization) correlated with higher Karnofsky scores, lower grade histology (initial and current), prior lower grade histology, smaller preoperative tumor volume, longer intervals from the time of initial diagnosis, and absence of prior chemotherapy. These results suggest that, in addition to established prognostic factors such as Karnofsky scores, other factors including prior chemotherapy administration, patterns of tumor recurrence, and tumor location may be important variables to consider in future Phase II-III clinical trials. Of the treatment variables analyzed, greater surgical debulking and smaller postoperative tumor volumes were associated with prolonged MTP but not MST, and greater myelotoxicity had a positive association with all outcomes. The significance of this latter relationship and its relevance to chemotherapy dosing will require further study. Standardization in the design and reporting of clinical trials and the use of computer-assisted tumor volume calculations to assess the extent of surgical resection and the response to therapy are advocated.

Feeding preterm infants after hospital discharge: effect of diet on body composition

Our purpose in this study was to examine whole body composition, using dual energy x-ray absorptiometry (DEXA) during dietary intervention in preterm infants (< or = 1750 g birthweight, < or = 34 wk gestation). At discharge, infants were randomized to be fed either a preterm infant formula (discharge-6 mo; group A) or a term formula (discharge-6 mo; group B), or the preterm formula (discharge-term) and the term formula (term-6 mo; group C). Nutrient intake was measured between each clinic visit. To measure body composition, DEXA was used at discharge, term, 12 wk, 6 mo, and 12 mo corrected age. The data were analyzed by ANOVA. At discharge, no differences were noted in patient characteristics between groups A, B, and C. Although energy intakes were similar, protein and mineral intakes differed between groups (A > C > B; p < 0.0001). During the study, weight gain and LM gain were greater in group A than B. At 12 mo, weight, LM, FM, and BMM but not % FM or BMD were greater in group A than B. However, the effects of diet were confined to boys, with no lasting effects seen in girls. In summary, therefore, DEXA was precise enough to detect differences in whole body composition during dietary intervention. Increased weight gain primarily reflected an increase in LM and is consistent with the idea that the preterm formula more closely met protein and/or protein-energy needs in rapidly growing preterm male infants.

Gender and sodium-ascorbate transporter isoforms determine ascorbate concentrations in mice

We evaluated the hypothesis that sodium-dependent vitamin C (ascorbate) transporters SVCT1 and SVCT2 (encoded by genes Slc23a1 and Slc23a2) regulate ascorbate concentrations in tissues of adult mice. Slc23a2+/- and Slc23a2+/+ mice were fed an ascorbate-free diet for 10-12 wk, and then segregated according to gender and genome, and were placed in groups of 3-4 in metabolic cages for 24-h urine collection. RT-PCR analysis showed that liver and kidney expressed mainly SVCT1, and brain, skeletal muscle, and spleen expressed predominantly SVCT2. Slc23a2+/- mice had low SVCT2 but normal SVCT1 messenger RNA (mRNA) levels, which did not differ between genders. Ascorbate concentrations were lower in Slc23a2+/- than Slc23a2+/+ mice in tissues where SVCT2 was the main isoform. Compared with males, females had lower ascorbate excretion and ascorbate:creatinine ratio in urine and had higher ascorbate concentrations in plasma and SVCT1-predominant tissues. SVCT2 contributed to a gender effect in spleen because males had higher spleen ascorbate concentration than females in wild-type but not in Slc23a2+/- mice. Hepatic gulonolactone oxidase mRNA and activity levels did not differ with genotype or gender, indicating no differences in ascorbate synthesis. We concluded that SVCT2 is a major determinant of ascorbate accumulation in tissues lacking SVCT1. The SVCT isoforms appear to function independently of one another because SVCT1 expression and ascorbate concentrations in SVCT1-predominant organs were not affected by SVCT2 deficiency. Additionally, lower ascorbate excretion in females may elevate the vitamin's concentrations in plasma and tissues expressing SVCT1 that, unlike SVCT2, is not saturated by plasma ascorbate concentrations.

Disease and symptom severity, functional status, and quality of life in chronic bronchitis and emphysema (CBE)

A path analysis model examined interrelationships among variables significantly associated with chronic dyspnea in chronic bronchitis and emphysema (CBE) and the relative influence of these variables on each other and on functional status and quality of life. Results from the 45 adults (mean age, 61) with moderate CBE disease severity showed that dyspnea severity has a sizable effect on functional status and quality of life. Disease severity was more strongly related to functional status than to quality of life. Depression and mastery had the strongest total effects on quality of life. Dyspnea severity had strong but separate effects on functional status and quality of life. From these preliminary results, it is suggested that a direct focus on psychologic interventions to ameliorate depression and improve mastery is likely to improve quality of life with some resultant positive effect on functional status.

A staff management system for maintaining improvements in continence with elderly nursing home residents

We developed a staff management system for maintaining treatment gains achieved on a specialized continence unit located in a geriatric nursing home. Geriatric assistants learned to use a prompted voiding procedure to maintain improved dryness for 4 elderly residents. The staff management system included self-monitoring and recording of prompted voiding activities and supervisory monitoring and feedback based on group performance of these activities. Results show that the system was effective in maintaining prompted voiding activities with corresponding maintenance of improved patient continence. However, a gradual decline in staff performance was noted 4 to 5 months after the initiation of the system. During a subsequent phase of the study, provision of individual feedback restored staff performance to previous levels. Results are discussed in relation to the practicality of prompted voiding interventions in nursing home environments and the applicability of staff management systems in this setting.

A descriptive analysis of nursing staff behaviors in a teaching nursing home: differences among NAs, LPNs, and RNs

Various staff behaviors in a nursing home were sampled seven times a day, 5 days a week over 37 months and were coded separately for LPNs, RNs, and NAs. The behavior most frequently observed was patient care, which occurred during 56.9% of the samples. We observed staff interacting with patients during 10.7% and with other staff during 19.5% of the samples. The LPNs displayed significantly more patient care behaviors and NAs significantly more nonwork behaviors than other nursing staff. RNs displayed the least nonwork behavior. We conclude that nursing staff devote most of their time to patient needs and relatively little time to nonproductive activities.

Socio-economic and ethnic inequalities in diabetes retinal screening

OBJECTIVE

We aimed to quantify socio-economic and ethnic inequalities in diabetes retinal screening.

METHODS

Data were analysed for the retinal screening programme for three South London boroughs for the 18-month period to February 2009. Sight-threatening diabetic retinopathy (STDR) was defined as the occurrence of diabetic maculopathy, severe non-proliferative or proliferative diabetic retinopathy. Odds ratios were adjusted for sex, age group, duration and type of diabetes, self-reported ethnicity and deprivation quintile by participant postal code.

RESULTS

There were 76 351 records obtained but, after excluding duplicate and ineligible records, data were analysed for 59 495 records from 31 484 subjects. There were 7026 (22%) subjects called for appointments who were not screened in the period, with 24 458 (78%) having one or more screening episodes. Non-attendance for screening was highest in young adults aged 18-34 years (32%) and in those aged 85 years or greater (28%). In the most deprived quintile, non-attendance was 23% compared with 21% in the least deprived quintile [odds ratio (OR) 1.37, 95% confidence interval (CI) 1.16-1.61, P < 0.001]. There were 2819 (11.5%) participants with STDR, including 10.8% in the least deprived quintile and 12.2% in the most deprived quintile (OR 1.10, 95% CI 0.95-1.16, P = 0.196). Compared with white Europeans (9.4%), STDR was higher in Africans (15.2%) and African Caribbeans (14.7%), resulting from a higher frequency of diabetic maculopathy.

CONCLUSION

Socio-economic inequality in diabetes retinal screening may be smaller than reported in earlier studies. This study suggested an increased frequency of diabetic maculopathy among participants of African origins.

Better maintained adherence on switching from twice-daily to once-daily therapy for HIV: a 24-week randomized trial of treatment simplification using stavudine prolonged-release capsules

BACKGROUND

Adherence to antiretroviral therapy is critical to treatment outcomes. Adherence studies in other therapeutic areas of medicine suggest that once-daily regimens support improved adherence when compared to twice-daily therapy. An expansion in the range of once-daily antiretrovirals is making once-daily therapy possible for persons with HIV infection.

METHODS

A 24-week randomized open-label simplification study of twice-daily regimens based on stavudine immediate release or zidovudine to an all once-daily regimen based on the stavudine prolonged-release capsule (PRC), in persons with complete virological suppression on regimens also including efavirenz and lamivudine, was carried out. Subjects were assessed for adherence [using the Medication Event Monitoring System (MEMS) cap; Aardex Corporation, Union City, CA, USA], quality of life, tolerability and efficacy.

RESULTS

Forty-three patients were randomly assigned: 21 remained on their original regimen and 22 switched to once-daily therapy with stavudine PRC. Although high levels of adherence and good quality of life were present at study enrollment, adherence declined to a significantly lesser extent at week 24 in the group that switched to once-daily therapy. Efficacy was maintained in both groups and there were no differences in tolerability or toxicity.

CONCLUSIONS

Subjects switching from twice-daily therapy to once-daily therapy demonstrate less of a decline in adherence over 24 weeks. A once-daily regimen including stavudine PRC is as effective and tolerable as a regimen containing the twice-daily formulation.

Body composition of preterm infants during infancy

AIMS

To examine body composition in preterm infants.

METHODS

Body composition was measured by dual energy x-ray absorptiometry (DEXA) at hospital discharge, term, 12 weeks, and at 6 and 12 months corrected age in 125 infants (birthweight < or = 1750 g, gestational age < or = 34 weeks).

RESULTS

Body weight derived by DEXA accurately predicted that determined by conventional scales. In both sexes lean mass (LM), fat mass (FM), %FM, bone area (BA), bone mineral mass (BMM), and bone mineral density (BMD) increased rapidly during the study; significant changes were detectable between discharge and term. At 12 months, LM, BA, and BMM, but not FM, %FM, or BMD were greater in boys than in girls. Corrected for age, LM was less than those of the reference term infant; FM and %FM were similar; BMM was greater. Corrected for weight, LM was similar to those of the reference infant, while the FM and %FM of study infants were slightly greater.

CONCLUSIONS

DEXA accurately measures body mass. Body composition in preterm boys and girls differs. Interpretation of DEXA values may depend on whether age or body weight are regarded as the appropriate reference.

Effects of a non-steroidal anti-inflammatory drug on delayed onset muscle soreness and indices of damage

Twenty untrained male volunteers were required to run downhill for 45 minutes on a motor driven treadmill to induce muscle soreness. The volunteers took diclofenac or placebo before and for 72 hours after two runs 10 weeks apart, in a randomised double blind crossover design. Subjective soreness was assessed before and at intervals up to 72 hours after each run; venous blood samples, collected at the same time intervals, were used to estimate serum activities of creatine kinase, lactate dehydrogenase and aspartate aminotransferase and serum concentrations of creatinine and urea. Subjective soreness and the biochemical parameters increased after both runs, although the serum enzyme response to the second run was reduced. Diclofenac had no influence on the serum biochemical response to downhill running. Although overall soreness was not affected by diclofenac, individual soreness measurements were reduced by diclofenac at the first period of the study. These results suggest that diclofenac does not influence muscle damage, but may slightly reduce the associated soreness.

Glucocorticoid regulation of prolactin receptors on mammary cells in culture

Mouse mammary epithelial cultures were examined for the ability to specifically bind [125I]PRL after cultivation on floating collagen gels. Corticosterone, particularly hydrocortisone, were effective in increasing the ability of mouse mammary cells to bind [125I]PRL. The absence of a glucocorticoid in the medium resulted in a loss of PRL binding during the 3 days in culture. 17 beta-Estradiol, progesterone, and aldosterone at equal molar concentration had no or only a small effect in increasing [125I]PRL binding.

Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2)

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).