Time of day effect on balance performance,functional capacities and risk of fall in women with rheumatoid arthritis

ABSTRACT

Objective: This study explored the time of day effect of balance performance, functional capacities and risk of fall in three different times in patients with rheumatoid arthritis (RA) and the association between these variations and those of RA symptoms.

Methods: A “discontinual” protocol, composed of three test sessions, carried out at 6 am, 2 pm and 10 pm was set up, in order to investigate the time of day effect of balance performance, functional capacities, risk of fall, stiffness, range of motion, swollen and painful joints in women with RA.

Results: Time Up and Go Test (TUGT), Functional Reach Test (FRT) and tinetti test scores were significantly higher (p < .01) at 6 am and at 10 pm compared to 2 pm. Stiffness, range of motion, swollen and painful joints values were significantly higher (p < .01) at 6 am and at 10 pm compared to 2 pm. A significant difference was observed on the stiffness, range of motion and swollen joints values between 6 am and 10 pm that were higher at 6 am (p < .05).

Using Pearson’s coefficient, correlations were found between RA symptom values; and TUGT, FRT and Tinetti test scores.

Conclusion: Results showed a time of day effect of balance performance, functional capacities and risk of falls in women with RA. This variation indicates an alteration of performance at 6 am and 10 pm. Fluctuations of stiffness, limited range of motion, swollen and painful joints noted are concomitant to those of balance performance, functional capacities, and risk of fall.

Abbreviations: RA: rheumatoid arthritis; H&O questionnaire: Horne and Ostberg questionnaire; PSQI: Pittsburgh sleep quality index; HAQ: health assessment questionnaire; SF-36: the short form-36; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; TUGT: Time Up and Go Test; FRT: Functional Reach Test     

Cardiovascular adaptations to exercise training in the elderly

Maximal O2 uptake (VO2max) and left ventricular function decrease with age. Endurance exercise training of sufficient intensity, frequency, and duration increases VO2max in the elderly. The mechanisms underlying the increased VO2max in the elderly are enhanced O2 extraction of trained muscle during maximal exercise leading to a wider arteriovenous O2 difference, and higher cardiac output in the trained state. However, increased cardiac output during true maximal exercise has not been documented in elderly subjects. Endurance exercise training results in a lower heart rate and rate pressure product during submaximal exercise at a given intensity. However, no improvement in left ventricular function has been reported in the elderly after exercise training. Highly trained master athletes exhibit proportional increases in the left ventricular end-diastolic dimension and wall thickness suggestive of volume-overload hypertrophy compared with age-matched sedentary controls. The magnitude of left ventricular enlargement is similar to that in young athletes. The failure of exercise training to alter the age-related deterioration of left ventricular function in the elderly may reflect an insufficient training stimulus rather than the inability of the heart to adapt to training in elderly subjects.     

Structure of the gene of tum- transplantation antigen P91A: the mutated exon encodes a peptide recognized with Ld by cytolytic T cells

Mutagen treatment of mouse P815 tumor cells produces immunogenic mutants that express new transplantation antigens (tum- antigens) recognized by cytolytic T cells. We found that the gene conferring expression of tum- antigen P91A contains 12 exons, encoding a 60 kd protein lacking a typical N-terminal signal sequence. The sequence shows no significant similarity with sequences in current data bases. A mutation that causes expression of the antigen is located in exon 4; it is the only apparent difference between the normal and the antigenic alleles. A short synthetic peptide corresponding to a region of exon 4 located around this mutation makes P815 cells sensitive to lysis by anti-P91A cytolytic T cells. The mutation creates a strong aggretope enabling the peptide to bind the H-2 Ld molecule. Several secondary tumor cell variants that no longer express tum- antigen P91A were found to carry deletions in the gene.     

Interspecific hybridization of cultivated rice, Oryza sativa L. with the wild rice, O. minuta Presl.

Crosses were made between four varieties (Mahsuri, Setanjung, MR84 and MR103) of Oryza sativa L. (2n=24, AA) and one accession of O. minuta (2n= 8, BBCC). The seed set obtained ranged between 9.5% and 25.1% depending on the rice variety used. By rescuing 14-day-old embryos and culturing them on 25%-strength MS medium we obtained a total of 414 F₁ hybrids. The F₁s were vigorous, tillered profusely, were perennial and male-sterile. The hybrids were triploid (ABC) with 36 chromosomes and showed irregular meiosis. The average frequency and range of chromosome associations at metaphase I or early anaphase I pollen mother cells of F₁ plants were 29.31(16–36) Is +3.32(0–10) IIs+0.016(0–1) IIIs+0.002(0–1) IVs. Upon backcrossing the original triploid hybrids and colchicine-treated hybrids to their respective recurrent parents, and further embryo rescue, 17 backcross-1 (BC₁) plants were obtained. Of all the crosses using MR84, no BC₁ plant was obtained even after pollinating 13 894 spikelets of the triploid hybrid. The BC₁s were similar in appearence to the F₁s and were male-sterile, their chromosome number ranged from 44 to 48. By backcrossing these BC₁s and nurturing them through embryo rescue, we obtained 32 BC₂ plants. Of these, however, only 18 plants grew vigorously. One of these plants has 24 chromosomes and the other 17 have chromosome numbers ranging between 30 and 37. The 24-chromosome plant was morphologically similar to the O. sativa parent and was partially fertile with a pollen and spikelet fertility of 58.8% and 12.5% respectively. All of the F₁ and BC₁ plants were found to be resistant to five Malaysian isolates (XO66, XO99, XO100, XO257 and XO319) of Xanthomonas campestris pv oryzae. Amongst the BC₂s, the reaction varied from resistant to moderately susceptible. The 24-chromosome BC₂ plant was resistant to the four isolates and moderately resistant to isolate XO100 to which the O. sativa parent was susceptible.Part of PhD thesis submitted by first author to Universiti Kebangsaan Malaysia, Bangi     

Purification of amoebolytic substances from Bacillus licheniformis M-4

Three antibiotic peptides with amoebolytic activity have been purified from culture supernatants of Bacillus licheniformis M-4 (amoebicins m4-A, m4-B, and m4-C). They were hydrophilic peptides consisting of six different amino acids (Asp, Glu, Ser, Thr, Pro, Tyr). Their molecular weights ranged from 3,000 to 3,200. Purified amoebicins were active against human pathogenic and non-pathogenic strains of Naegleria. They also showed a broad antifungal spectrum, but a narrow antibacterial activity.Abbreviations (TFA) Trifluoroacetic acid     

Cardiovascular adaptations to 10days of cycle exercise

Mier, Constance M., Michael J. Turner, Ali A. Ehsani, andRobert J. Spina. Cardiovascular adaptations to 10 days of cycleexercise. J. Appl. Physiol. 83(6):1900-1906, 1997.We hypothesized that 10 days of training wouldenhance cardiac output (CO) and stroke volume (SV) during peak exerciseand increase the inotropic response to -adrenergic stimulation. Tensubjects [age 26 ± 2 (SE) yr] trained on a cycleergometer for 10 days. At peak exercise, training increasedO₂ uptake, CO, and SV(P < 0.001). Left ventricular (LV)size and function at rest were assessed with two-dimensional echocardiography before (baseline) and after atropine injection (1.0 mg) and during four graded doses of dobutamine. LV end-diastolic diameter increased with training (P < 0.02), whereas LV wall thickness was unchanged. LV contractileperformance was assessed by relating fractional shortening (FS) to theestimated end-systolic wall stress(_ES). Training increased theslope of the FS-_ES relationship (P < 0.05), indicating enhancedsystolic function. The increase in slope correlated with increases inCO (r = 0.71,P < 0.05) and SV(r = 0.70,P < 0.05). The increase in bloodvolume also correlated with increases in CO(r = 0.80, P < 0.01) and SV (r = 0.85, P < 0.004). These datashow that 10 days of training enhance the inotropic response to-adrenergic stimulation, associated with increases in CO and SVduring peak exercise.

     

Direct and efficient plant regeneration from leaf explants of Solanum tuberosum l. cv. Bintje

Summary A two-step procedure was used for plant regeneration from in vitro grown leaf strips (2–3 mm wide) of cv. Bintje. Step I medium was designed with 2,4-dichlorophenoxycetic acid (2,4-D) at 0.0 or 9.0 M, in combination with 2.28 M kinetin (K), benzyl adenine (BA), zeatin (Z) or zeatin riboside (ZR). Step II media were 2,4-D-free media containing 5.78 M gibberellic acid (GA3) and growth regulators similar to those of step I media. Leaf explants cultured in medium I containing zeatin riboside or zeatin for 6 days and then subcultured in medium II containing zeatin riboside produced numerous shoots without callus formation. Zeatin riboside containing step I and II media caused shoot regeneration in a high number (97.5±2.2) of explants. Approximately, 33.7±8.4 shoots were regenerated from each leaf explant.Abbreviations BA benzyladenine - Z zeatin - ZR zeatin riboside (trans isomer) - 2,4-D 2,4-dichlorophenoxyacetic acid     

Plant regeneration via somatic embryogenesis in creeping bentgrass (Agrostis palustris Huds.)

We have established a high-frequency plant regeneration system via somatic embryogenesis from mature seeds of creeping bentgrass (Agrostis palustris Huds). The effects of 2,4-dichlorophenoxyacetic acid (2,4-D), 3.6-dichloroo-anisic acid (dicamba) and 6-benzyladenine (BA) on callus formation and embryogenesis were evaluated. Callus produced on the Murashige and Skoog (MS) (1962) medium containing 2,4-D had low embryogenic potency. In the presence of 30 M dicamba, addition of 2.25 to 9 M BA significantly enhanced embryogenic callus formation over dicamba alone. Optimum frequency of somatic embryogenesis was achieved on MS basal medium containing 30 M dicamba and 2.25 M BA. Over 80% of somatic embryos germinated and formed plantlets on half-strength MS basal medium. These plantlets grew normally in the greenhouse.Abbreviations MS Murashige and Skoog medium - 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzyladenine - dicamba 3, 6-dichloro-o-anisic acid