Bright light treatment of winter depression: morning versus evening light

In a randomized crossover design, 7 patients with winter depression were treated with 7 d of bright morning light (0600 to 0800) and 7 d of evening light (2000 to 2200). Bright lights in the morning significantly reduced the Hamilton Rating Scale for Depression (HRSD) score (18.4 to 5.0); the bright light in the evening moderately decreased the HRSD score (19.4 to 15.1). The improvement in the HRSD score was significantly greater with morning light than with evening light.     

Matrix metalloproteinases and aggrecanases cleave aggrecan in different zones of normal cartilage but colocalize in the development of osteoarthritic lesions in STR/ort mice.

OBJECTIVE: To map aggrecan cleavage by matrix metalloproteinases (MMPs) and aggrecanases in normal murine tibial articular cartilage (CBA strain) and in the development of spontaneous osteoarthritis (OA) in the STR/ort mouse and to assess the influence of sex hormone status on these conditions in gonadectomized STR/ort mice. METHODS: The distributions of neoepitopes of aggrecan generated by MMP (VDIPEN) and aggrecanase (NITEGE) cleavage were investigated by immunohistochemistry. RESULTS: VDIPEN neoepitope was detected mainly in the pericellular matrix of deep-zone chondrocytes in normal tibial cartilage from STR/ort and CBA mice. In early OA, VDIPEN immunostaining also localized to the pericellular matrix of chondrocytes at the site of the lesion. With increasing severity of OA lesions, VDIPEN immunostaining was also detected in the interterritorial matrix, close to the site of the lesion. In contrast, NITEGE mapped most strongly to the pericellular matrix of upper-zone chondrocytes in normal tibial cartilage. As with VDIPEN, NITEGE was strongly expressed in the pericellular matrix at the site of early OA lesions. With advancing OA, NITEGE colocalized with VDIPEN in both the pericellular and interterritorial matrices of chondrocytes adjacent to OA lesions and in those of the deep zones. Hormone status did not appear to influence the development of OA or the distribution of aggrecan neoepitopes in STR/ort mice. CONCLUSION: MMP- and aggrecanase-generated neoepitopes map predominantly to different regions in normal murine tibial cartilage. However, both groups of enzymes generate increased amounts of neoepitopes in pericellular and interterritorial matrix adjacent to histopathologic lesions of OA. Aggrecan degradation and the development of OA appear to be independent of sex hormone status in this model.     

Electrophoretic karyotype for Dictyostelium discoideum.

This paper reports on the separation of the Dictyostelium discoideum chromosomes by pulse-field electrophoresis and the correlation of the electrophoretic pattern with linkage groups established by classical genetic methods. In two commonly used laboratory strains, five chromosome-sized DNA molecules have been identified. Although the majority of the molecular probes used in this study can be unambiguously assigned to established linkage groups, the electrophoretic karyotype differs between the closely related strains AX3k and NC4, suggesting that chromosomal fragmentation may have occurred during their maintenance and growth. The largest chromosome identified in this study is approximately 9 million base pairs. To achieve resolution with molecules of this size, programmed voltage gradients were used in addition to programmed pulse times.     

Angiotensin-converting enzyme inhibition attenuates renal platelet-derived growth factor gene expression and cell proliferation in subtotal nephrectomy

Cell proliferation, matrix accumulation and cell infiltration are characteristic features of progressive glomerulosclerosis and tubulointerstitial fibrosis. Platelet‐derived growth factor (PDGF), a cytokine which has proliferative, prosclerotic and chemokine properties, has been shown to be upregulated in the rat remnant kidney model. Inhibition of the renin–angiotensin system by angiotensin‐converting enzyme (ACE) inhibitors has a beneficial effect on renal function and morphology, but the effect of ACE inhibition on PDGF gene expression and PDGF‐mediated cellular proliferation in subtotal nephrectomy has not been studied in detail. Twelve rats were subtotally nephrectomized (STNx) and received either the ACE inhibitor perindopril or a placebo for 12 weeks. Five sham‐operated rats served as controls. Subtotal nephrectomy was associated with hypertension, proteinuria, elevated plasma creatinine and increased kidney weight. After 12 weeks, PDGF B‐chain mRNA was significantly upregulated in the glomeruli and tubulointerstitium of subtotally nephrectomized rats. ACE inhibition attenuated PDGF mRNA expression in association with a reduction in tubular and glomerular proliferation, as assessed by staining for proliferating cell nuclear antigen. In the context of the known in vitro and in vivo effects of PDGF, it is postulated that the renoprotective action of ACE inhibitors may be partially related to PDGF‐mediated antiproliferative mechanisms.     

The relationship between motivational structure,sense of control,intrinsic motivation and university students' alcohol consumption

The aim of this study was to determine how sense of control and intrinsic motivation are related to university students' motivational structure and alcohol consumption. Participants were 94 university students who completed the Personal Concerns Inventory, Shapiro Control Inventory, Helplessness Questionnaire, Intrinsic–Extrinsic Aspirations Scale, and Alcohol Use Questionnaire. Results showed that sense of control and intrinsic motivation were positively correlated with adaptive motivation and negatively correlated with alcohol consumption. Mediational analyses indicated that adaptive motivation fully mediated the relationship between sense of control/intrinsic motivation and alcohol consumption.     

Laboratory properties of cold-adapted influenza B live vaccine strains developed in the US and USSR, and their B/Ann Arbor/1/86 cold-adapted reassortant vaccine candidates

The adaptation of two influenza B strains (B/Leningrad/14/55 and B/Ann Arbor/1/66) to replication at 25 degrees C is described. Comparison of the two viruses indicates that both also exhibit temperature sensitive phenotypes, although that of the virus B/Leningrad/14/55 is less pronounced. When inoculated into ferrets both viruses replicate well in the trachea, but only the B/Leningrad/14/55 cold-adapted virus replicates in the lungs. This virus exhibited a moderate level of attenuation in the animals, in contrast to the B/Ann Arbor/1/66 cold-adapted virus, which was fully attenuated. Reassortant viruses deriving the surface antigens of the contemporary wild type virus B/Ann Arbor/1/86 and most or all of their other genes, from one or other cold-adapted parent, were virtually indistinguishable from their respective cold-adapted parents. The B/Leningrad/14/55 reassortant was slightly more attenuated than its cold-adapted parent in ferrets. These studies extend knowledge of the properties of viruses used to prepare experimental live influenza B human vaccines.     

The effect of salts on the micellization temperature of aqueous poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) solutions and the dissolution rate and water diffusion coefficient in their corresponding gels.

Studies were performed to examine the effect of ionic salts on phase transitions, dissolution rates, and diffusion coefficients of water in gels of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) with polymer concentrations ranging from 22 to 32% w/w and salt concentrations ranging from 0 to 1.5% w/w. Salts tested include Na(3)PO(4), Na(2)SO(4), Na(2)HPO(4), NaH(2)PO(4), NaCH(3)CO(2), NaCl, and KI. Micellization transition temperatures were obtained using differential scanning calorimetry. The dissolution rates were obtained by measurement of the surface erosion rates, and diffusion coefficients were obtained by using a method to analyze the intrusion of water into the aqueous gels. It was found that salts had no effect on the dissolution rate of the polymer gels into deionized water. However, when the salt concentration in the aqueous dissolution media was adjusted to match the concentration in the gels, the dissolution rate of the polymer gel decreased with increasing salt concentration. The salts also had a profound effect on the critical micellization temperature (CMT) and the diffusion coefficient of water within the gel. The diffusion coefficient and CMT decreased in the presence of salts. The magnitude of these effects was comparable to their placement on the Hofmeister, or lyotropic series for salts. The effects of polymer and salt concentrations on the CMT were quantified, and a single correlation was proposed to predict the micellization temperatures for a wide range of salt and polymer concentrations.     

Acute cholecystitis in the emergency department

Acute cholecystitis is a frequent consideration in patients presenting to the emergency department with the challenging complaint of upper abdominal pain. It is estimated that 20% of American adults have gallstones, and of these a large percentage (about one-third) will at some point develop acute cholecystitis. The epidemiology and associated risk factors of acute cholecystitis are briefly reviewed along with the pathogenesis and clinical presentation of the disease. Finally, an approach to the diagnosis in the emergency department and suggested management is discussed including a comparison of the strengths and weaknesses of ultrasonography and hepatobilary scintigraphy.     

Changes in collagen biosynthesis, types, and mechanics of aorta in hypertensive rats

The purpose of this study was to relate changes in collagen composition with the mechanical properties of aortas of spontaneously hypertensive rats (SHRs). SHRs and normal Wistar-Kyoto (WKY) rats were killed at ages 6 and 20 weeks, and their aortas were removed. A portion of each aorta was used for determination of passive mechanical properties, and the remainder was incubated with carbon 14-labeled proline containing medium for 18 hours at 37 degrees C. After incubation, the tissues were lyophilized, and aliquots were used for sequential extraction with neutral salt, acetic acid, and pepsin at 4 degrees C. The pepsin extracts that contained most of the collagen were used for characterization of the collagen types and synthesis of collagen by the production of [14C]-labeled hydroxyproline. Collagen concentration decreased approximately 16% in both 6- and 20-week-old aortas, but collagen synthesis was about twofold higher in the aortas from both 6- and 20-week-old SHRs. Although type V collagen represented a minor fraction of total collagen (5%) in the aortas of WKY rats, it was twofold greater in the hypertensive animals. This increment in type V collagen in SHR aortas was accompanied by a reduction in the proportion of type I collagen, with no change in the proportion of type III. Study of the passive mechanical properties of the tissues showed that SHR aortas were stiffer compared with aortas of WKY rats, with a larger difference at 20 weeks than at 6 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)