scAAV-mediated gene transfer of interleukin-1-receptor antagonist to synovium and articular cartilage in large mammalian joints.

With the long-term goal of developing a gene-based treatment for osteoarthritis (OA), we performed studies to evaluate the equine joint as a model for adeno-associated virus (AAV)-mediated gene transfer to large, weight-bearing human joints. A self-complementary AAV2 vector containing the coding regions for human interleukin-1-receptor antagonist (hIL-1Ra) or green fluorescent protein was packaged in AAV capsid serotypes 1, 2, 5, 8 and 9. Following infection of human and equine synovial fibroblasts in culture, we found that both were only receptive to transduction with AAV1, 2 and 5. For these serotypes, however, transgene expression from the equine cells was consistently at least 10-fold higher. Analyses of AAV surface receptor molecules and intracellular trafficking of vector genomes implicate enhanced viral uptake by the equine cells. Following delivery of 1 × 10(11) vector genomes of serotypes 2, 5 and 8 into the forelimb joints of the horse, all three enabled hIL-1Ra expression at biologically relevant levels and effectively transduced the same cell types, primarily synovial fibroblasts and, to a lesser degree, chondrocytes in articular cartilage. These results provide optimism that AAV vectors can be effectively adapted for gene delivery to large human joints affected by OA.

Effects of 21 days of bed rest, with or without artificial gravity, on nutritional status of humans.

Spaceflight and bed rest models of microgravity have profound effects on physiological systems, including the cardiovascular, musculoskeletal, and immune systems. These effects can be exacerbated by suboptimal nutrient status, and therefore it is critical to monitor nutritional status when evaluating countermeasures to mitigate negative effects of spaceflight. As part of a larger study to investigate the usefulness of artificial gravity as a countermeasure for musculoskeletal and cardiovascular deficits during bed rest, we tested the hypothesis that artificial gravity would have an effect on some aspects of nutritional status. Dietary intake was recorded daily before, during, and after 21 days of bed rest with artificial gravity (n = 8) or bed rest alone (n = 7). We examined body composition, hematology, general blood chemistry, markers of oxidative damage, and blood levels of selected vitamins and minerals before, during, and after the bed rest period. Several indicators of vitamin status changed in response to diet changes: serum alpha- and gamma-tocopherol and urinary 4-pyridoxic acid decreased (P < 0.001) and plasma beta-carotene increased (P < 0.001) in both groups during bed rest compared with before bed rest. A decrease in hematocrit (P < 0.001) after bed rest was accompanied by a decrease in transferrin (P < 0.001), but transferrin receptors were not changed. These data provide evidence that artificial gravity itself does not negatively affect nutritional status during bed rest. Likewise, artificial gravity has no protective effect on nutritional status during bed rest.

The effect of adrenergic suppression induced by guanabenz administration on exercising thoroughbred horses.

REASONS FOR PERFORMING STUDY: Adrenergic activity accompanies intense exercise and mediates physiological and metabolic responses to exercise. Guanabenz, an antihypertensive drug marketed for human usage, depresses brain vasomotor and cardioaccelerator centres, blocks peripherally adrenergic neurons and is reportedly used as a calming agent in horses but little is known of its effects in the species. OBJECTIVES: To determine if guanabenz induces measurable signs of adrenergic suppression on fit Thoroughbred horses undergoing intense exercise. METHODS: In a random crossover design, 12 exercise conditioned Thoroughbred horses each received guanabenz (0.08 mg/kg bwt i.v.) and placebo at 3-week intervals. An incremental exercise test to exhaustion on a treadmill followed treatment by 1 h. Heart rate, oxygen consumption, carbon dioxide production, plasma lactate, catecholamines, adrenocorticotropic hormone (ACTH) and cortisol, and time to fatigue were monitored. Statistical analysis was performed using mixed-effects linear modelling. RESULTS: Mean heart rate during the exercise period was lower in guanabenz-treated horses (P = 0.04). Mean concentrations of plasma cortisol (P = 0.02) and adrenaline (P = 0.03) were lower for guanabenz-treated horses during the exercise period. Mean run time was slightly but not significantly longer for guanabenz-treated horses, (P = 0.053). No significant effects of guanabenz administration were found for oxygen consumption, carbon dioxide production nor for plasma lactate, noradrenaline and ACTH concentrations. CONCLUSION: Guanabenz administration induced signs of adrenergic suppression including plasma cortisol and adrenaline concentrations and heart rate and may enhance endurance, but did not eliminate increases in hormone concentrations induced by exercise. Clear determination of a positive performance effect of adrenaline, but not noradrenaline, suppression is needed before clinical significance can be determined.

Nutritional status assessment in semiclosed environments: ground-based and space flight studies in humans.

Adequate nutrition is critical during long-term spaceflight, as is the ability to easily monitor dietary intake. A comprehensive nutritional status assessment profile was designed for use before, during and after flight. It included assessment of both dietary intake and biochemical markers of nutritional status. A spaceflight food-frequency questionnaire (FFQ) was developed to evaluate intake of key nutrients during spaceflight. The nutritional status assessment protocol was evaluated during two ground-based closed-chamber studies (60 and 91 d; n = 4/study), and was implemented for two astronauts during 4-mo stays on the Mir space station. Ground-based studies indicated that the FFQ, administered daily or weekly, adequately estimated intake of key nutrients. Chamber subjects maintained prechamber energy intake and body weight. Astronauts tended to eat 40--50% of WHO-predicted energy requirements, and lost >10% of preflight body mass. Serum ferritin levels were lower after the chamber stays, despite adequate iron intake. Red blood cell folate concentrations were increased after the chamber studies. Vitamin D stores were decreased by > 40% on chamber egress and after spaceflight. Mir crew members had decreased levels of most nutritional indices, but these are difficult to interpret given the insufficient energy intake and loss of body mass. Spaceflight food systems can provide adequate intake of macronutrients, although, as expected, micronutrient intake is a concern for any closed or semiclosed food system. These data demonstrate the utility and importance of nutritional status assessment during spaceflight and of the FFQ during extended-duration spaceflight.

Simulated microgravity [bed rest] has little influence on taste, odor or trigeminal sensitivity.

Anecdotal evidence suggests that astronauts' perceptions of foods in space flight may differ from their perceptions of the same foods on Earth. Fluid shifts toward the head experienced in space may alter the astronauts' sensitivity to odors and tastes, producing altered perceptions. Our objective was to determine whether head-down bed rest, which produces similar fluid shifts, would produce changes in sensitivity to taste, odor or trigeminal sensations. Six subjects were rested three times prior to bed rest, three times during bed rest and two times after bed rest to determine their threshold sensitivity to the odors isoamylbutyrate and menthone, the tastants sucrose, sodium chloride, citric acid, quinine and monosodium glutamate, and to capsaicin. Thresholds were measured using a modified staircase procedure. Self-reported congestion was also recorded at each test time. Thresholds for monosodium glutamate where slightly higher during bed rest. None of the other thresholds were altered by bed rest.

Calcium metabolism before, during, and after a 3-mo spaceflight: kinetic and biochemical changes.

The loss of bone during spaceflight is considered a physiological obstacle for the exploration of other planets. This report of calcium metabolism before, during, and after long-duration spaceflight extends results from Skylab missions in the 1970s. Biochemical and endocrine indexes of calcium and bone metabolism were measured together with calcium absorption, excretion, and bone turnover using stable isotopes. Studies were conducted before, during, and after flight in three male subjects. Subjects varied in physical activity, yet all lost weight during flight. During flight, calcium intake and absorption decreased up to 50%, urinary calcium excretion increased up to 50%, and bone resorption (determined by kinetics or bone markers) increased by over 50%. Osteocalcin and bone-specific alkaline phosphatase, markers of bone formation, increased after flight. Subjects lost approximately 250 mg bone calcium per day during flight and regained bone calcium at a slower rate of approximately 100 mg/day for up to 3 mo after landing. Further studies are required to determine the time course of changes in calcium homeostasis during flight to develop and assess countermeasures against flight-induced bone loss.

Dietary studies in the joint US-Russian space program.

Metabolic experiments in the joint US-Russian space program involve analysis of food records, which include weighed foods, stable-isotope turnover, and biochemical samples collected before, during, and after the flights. This article describes the methods of monitoring dietary intake for this program.

Nutrition in space.

NASA: The authors review studies conducted to define nutritional requirements for astronauts during space flight and to assess nutrition before, during, and after space flight. Topics include space food systems, research and limitations on spacecraft, physiological adaptation to weightlessness, energy requirements, dietary intake during space flight, bone demineralization, gastrointestinal function, blood volume, and nutrition requirements for space flight. Benefits of space-related nutrition research are highlighted.^ieng

Nutrition in space: lessons from the past applied to the future.

From the basic impact of nutrient intake on health maintenance to the psychosocial benefits of mealtime, the role of nutrition in space is evident. In this discussion, dietary intake data from three space programs, Apollo, Space Shuttle, and Skylab, are presented. Data examination reveals that energy and fluid intakes are almost always lower than predicted. Nutrition in space has many areas of impact, including provision of required nutrients and maintenance of endocrine, immune, and musculoskeletal systems. Long-duration missions will require quantitation of nutrient requirements for maintenance of health and protection against the effects of microgravity. Psychosocial aspects of nutrition will also be important for more productive missions and crew morale. Realization of the full role of nutrition during spaceflight is critical for the success of extended-duration missions. Research conducted to determine the impact of spaceflight on human physiology and subsequent nutritional requirements will also have direct and indirect applications in Earth-based nutrition research.

Distribution and correlates of waist-to-hip ratio in black adults: the Pitt County Study.

A 1988 community-based survey of 1,784 black adults aged 25-50 years in Pitt County, North Carolina, found mean waist-to-hip ratios of 0.890 for men and 0.852 for women. Based on guidelines from the US Department of Agriculture, 20% of the men and 76% of the women had an elevated waist-to-hip ratio. Sedentary behavior was associated with elevated waist-to-hip ratio in men, while a similar excess was associated with alcohol consumption in women. Weak, nonsignificant associations with waist-to-hip ratio were observed for smoking. Socioeconomic status was unrelated to waist-to-hip ratio in men, but it had a strong inverse relation for women.

Prognostic factors associated with recurrence in clinical stage I adenocarcinoma of the endometrium.

Two hundred sixty-four consecutive patients with clinical stage I endometrial adenocarcinoma who underwent primary surgical therapy between July 1979 and August 1988 were followed prospectively and evaluated for disease recurrence for 8-112 months (mean 51.5). Thirty-three patients (12.5%) developed recurrence or died of disease. In univariate statistical analysis, prognostic factors significantly associated with disease recurrence were as follows: age (mean 68.6 years with versus 60.3 years without recurrence; P = .0001); histology (adenocarcinoma 8.8%, adenosquamous 35.7%, papillary 25%, clear-cell 57.1%; P less than .0001); tumor grade (grade 1, 7.7%, grade 2, 10.5%, grade 3, 36.1%; P less than .0001); depth of myometrial invasion (none 9.8%, less than one-half 7.4%, one-half or greater 29.6%; P = .0001); lymph node status (negative 8.3%, positive 47.6%; P less than .0001); non-nodal extrauterine disease spread (absent 11.0%, present 50%; P = .0003); peritoneal cytology (negative 9.4%, positive 26.3%; P = .004), and tumor size (2 cm or less 7%, greater than 2 cm 17.3%; P = .05). Cervical extension and uterine size had no significant effect on recurrence. Using multivariate analysis, grade 3 tumor (P = .002), advancing age (P = .004), lymph node metastasis (P = .006), and presence of extrauterine disease spread other than lymph node metastasis (P = .038) were the only variables significantly associated with disease recurrence or death. This study supports the new International Federation of Gynecology and Obstetrics surgical staging system for endometrial cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbachol modulates GIP-mediated insulin release from rat pancreatic lobules in vitro.

Rat pancreatic lobules were used to investigate the interaction of gastric inhibitory polypeptide (GIP), carbachol, glucose, and an amino acid mixture on insulin secretion. At 5 mM glucose, GIP (1.1 ng/ml) did not augment insulin secretion in the presence or absence of carbachol (5 X 10(-5)M) during a 210-min incubation. However, at 11 mM glucose, GIP did augment insulin secretion in the presence (342.5 +/- 62.0 vs. 212.5 +/- 50.5 microU . ml-1 . mg tissue-1, mean +/- SE; P less than 0.01) but not the absence (217.0 +/- 45.5 vs. 205.8 +/- 35.0 microU . ml-1 . mg tissue-1) of carbachol. During subsequent 30-min incubations, GIP was increased to a supra-physiological concentration of 11 ng/ml and again augmented insulin secretion with (65.8 +/- 10.8 vs. 27.8 +/- 2.4 microU . ml-1 . mg tissue-1 . h-1; P less than 0.001) but not without (37.2 +/- 1.8 vs. 30.2 +/- 2 microU . ml-1 . mg-1 tissue-1 . h-1) carbachol present. This GIP-mediated insulin secretion was blocked by atropine (34.8 to 1.8 vs. 37.6 +/- 1.6 microU . ml-1 . mg tissue-1 . h-1). At amino acid concentrations of 21 and 211 mM, but not 2.1 mM, GIP augmented insulin release but again only with carbachol present. In conclusion, porcine GIP augments amino acid as well as glucose-mediated insulin secretion in vitro. Furthermore, this biological action is dependent on an, as yet, unidentified cholinergic mechanism. The pathophysiological significance of the neural-hormonal interaction deserves further investigation.