A Non-Controlled Study of a Multi-Factorial Exercise and Nutritional Intervention to Improve Functional Performance and Prevent Frailty Progression in Community-Dwelling Pre-Frail Older Adults

Background

Preventing frailty is important to avoid adverse health outcomes. Intervention studies have largely focused on frail elderly, although the intermediate pre-frail state may be more amenable to improvement.

Objectives

This study aims to assess how physical performance may change among pre-frail elderly enrolled in a pragmatic non-controlled exercise and nutritional intervention programme.

Methods

This is a non-controlled study involving a 4-month exercise and nutritional intervention for community dwelling pre-frail older adults. Pre-frailty was defined as the presence of 1 or 2 positive responses on the FRAIL questionnaire, or evidence of weak grip strength (<26kg for males; <18kg for females) or slow gait speed (<0.8m/s) amongst participants who were asymptomatic on FRAIL. Physical performance in flexibility, grip and lower limb strength, endurance, balance, and Short Physical Performance Battery were measured at 3 time-points: baseline, 3-month from recruitment (without intervention), and immediate post-intervention. Repeated measures mixed model analysis was performed to compare physical performance measures across the 3 time-points.

Results

94 pre-frail participants were eligible for intervention, of whom 59 (mean age = 70.9±7.2 years) were ready for the post-intervention review. 21 (35.6%) transitioned to robust phenotype while 32 (54.2%) remained as pre-frail. Significant improvement post-intervention was observed in lower limb strength and power, evident on reduction in time taken for 5 sit-to-stand repetitions (0.46±0.20s, p=0.03). There was no significant change to the other physical performance measures examined.

Conclusion

We observed reversibility of pre-frailty, and the benefit of multi-component intervention in improving physical performance of pre-frail older adults. The findings in this non-controlled study will need to be corroborated with future controlled trials.

Rogue waves for a system of coupled derivative nonlinear Schrödinger equations

Rogue waves (RWs) are unexpectedly strong excitations emerging from an otherwise tranquil background. The nonlinear Schrödinger equation (NLSE), a ubiquitous model with wide applications to fluid mechanics, optics, plasmas, etc., exhibits RWs only in the regime of modulation instability (MI) of the background. For a system of multiple waveguides, the governing coupled NLSEs can produce regimes of MI and RWs, even if each component has dispersion and cubic nonlinearity of opposite signs. A similar effect is demonstrated here for a system of coupled derivative NLSEs (DNLSEs) where the special feature is the nonlinear self-steepening of narrow pulses. More precisely, these additional regimes of MI and RWs for coupled DNLSEs depend on the mismatch in group velocities between the components, and the parameters for cubic nonlinearity and self-steepening. RWs considered in this paper differ from those of the NLSEs in terms of the amplification ratio and criteria of existence. Applications to optics and plasma physics are discussed.

A coupled "AB" system: Rogue waves and modulation instabilities

Rogue waves are unexpectedly large and localized displacements from an equilibrium position or an otherwise calm background. For the nonlinear Schrödinger (NLS) model widely used in fluid mechanics and optics, these waves can occur only when dispersion and nonlinearity are of the same sign, a regime of modulation instability. For coupled NLS equations, rogue waves will arise even if dispersion and nonlinearity are of opposite signs in each component as new regimes of modulation instability will appear in the coupled system. The same phenomenon will be demonstrated here for a coupled "AB" system, a wave-current interaction model describing baroclinic instability processes in geophysical flows. Indeed, the onset of modulation instability correlates precisely with the existence criterion for rogue waves for this system. Transitions from "elevation" rogue waves to "depression" rogue waves are elucidated analytically. The dispersion relation as a polynomial of the fourth order may possess double pairs of complex roots, leading to multiple configurations of rogue waves for a given set of input parameters. For special parameter regimes, the dispersion relation reduces to a cubic polynomial, allowing the existence criterion for rogue waves to be computed explicitly. Numerical tests correlating modulation instability and evolution of rogue waves were conducted.

The impact of hepatitis B virus (HBV) infection on clinical outcomes of patients with diffuse large B-cell lymphoma

We performed a retrospective study to analyse the characteristics and clinical outcomes of diffuse large B-cell lymphoma (DLBCL) patients with hepatitis B virus (HBV) infection and compare with those without HBV infection. The occurrence of hepatitis after withdrawal of prophylactic antiviral treatment on completion of chemotherapy was also assessed. The HBsAg-positive patients were given prophylactic antiviral treatment until 6 months after finishing chemotherapy. A total of 81 patients were recruited with 16 in the HBsAg-positive group and 65 in the HBsAg-negative group. The clinical characteristics were similar in both groups of patients. There was no significant difference in complete remission rate between the two groups (63% in HBsAg-positive group vs. 54% in HBsAg-negative group, P = 0.59). There was also no statistically significant difference in overall survival between the two groups (P = 0.23). Four of the 16 HBsAg-positive patients (25%) had hepatitis after cessation of chemotherapy and prophylactic lamivudine. The mean time of onset of hepatitis was 3 months after stopping lamivudine. In conclusion, HBV infection did not appear to affect the prognosis of DLBCL patients given antiviral prophylaxis. It is reasonable to consider prophylactic antiviral therapy to extend to at least one year on completion of chemotherapy.

Is prior course of illness relevant to acute or longer-term outcomes in depressed out-patients? A STAR*D report

BACKGROUND

Major depressive disorder (MDD) is commonly chronic and/or recurrent. We aimed to determine whether a chronic and/or recurrent course of MDD is associated with acute and longer-term MDD treatment outcomes.

METHOD

This cohort study recruited out-patients aged 18-75 years with non-psychotic MDD from 18 primary and 23 psychiatric care clinics across the USA. Participants were grouped as: chronic (index episode >2 years) and recurrent (n = 398); chronic non-recurrent (n=257); non-chronic recurrent (n=1614); and non-chronic non-recurrent (n = 387). Acute treatment was up to 14 weeks of citalopram (≤ 60 mg/day) with up to 12 months of follow-up treatment. The primary outcomes for this report were remission [16-item Quick Inventory of Depressive Symptomatology - Self-Rated (QIDS-SR(16)) ≤ 5] or response (≥ 50% reduction from baseline in QIDS-SR(16)) and time to first relapse [first QIDS-SR16 by Interactive Voice Response (IVR) ≥ 11].

RESULTS

Most participants (85%) had a chronic and/or recurrent course; 15% had both. Chronic index episode was associated with greater sociodemographic disadvantage. Recurrent course was associated with earlier age of onset and greater family histories of depression and substance abuse. Remission rates were lowest and slowest for those with chronic index episodes. For participants in remission entering follow-up, relapse was most likely for the chronic and recurrent group, and least likely for the non-chronic, non-recurrent group. For participants not in remission when entering follow-up, prior course was unrelated to relapse.

CONCLUSIONS

Recurrent MDD is the norm for out-patients, of whom 15% also have a chronic index episode. Chronic and recurrent course of MDD may be useful in predicting acute and long-term MDD treatment outcomes.

Ministry of Health clinical practice guidelines: bipolar disorder

The Ministry of Health (MOH) has published clinical practice guidelines on Bipolar Disorder to provide doctors and patients in Singapore with evidence-based guidance on the management of bipolar disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Bipolar Disorder, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http: //www.moh.gov.sg/content/moh_web/home/Publications/guidelines/clinical_practiceguidelines/2011/bipolar_disorder.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Ministry of Health clinical practice guidelines: management of gambling disorders

The Ministry of Health (MOH) has published clinical practice guidelines on Management of Gambling Disorders to provide doctors and patients in Singapore with evidence-based guidance on the management of gambling disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Management of Gambling Disorders for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website (http://www.moh.gov.sg/mohcorp/publications.aspx?id=26136). The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Comparison of recombinant Escherichia coli strains for synthesis and accumulation of poly-(3-hydroxybutyric acid) and morphological changes

A stable high-copy-number plasmid pSYL105 containing the Alcaligenes eutrophus polyhydroxyalkanoic acid (PHA) biosynthesis genes was constructed. This plasmid was transferred to seven Escherichia coli strains (K12, B, W, XL1-Blue, JM109, DH5alpha, and HB101), which were subsequently compared for their ability to synthesize and accumulate ploy- (3-hydroxybutyric acid) (PHB). Growth of recombinant cells and PHB synthesis were investigated in detail in Luria-Bertani (LB) medium containing 20 g/L glucose. Cell growth, the rate of PHB synthesis, the extent of PHB accumulation, the amount of glucose utilized, and the amount of acetate formed varied from one strain to another. XL1-Blue (pSYL105) and B (pSYL105) synthesized PHB at the fastest rate, which was ca. 0.2 g PHB/g true cell mass-h, and produced PHB up to 6-7 g/L. The yields of cell mass, true cell mass, and PHB varied considerably among the strains. The PHB yield of XL1-Blue (pSYL105) in LB plus 20 g/L glucose was as high as 0.369 g PHB/g glucose. Strains W (pSYL105) and K12 (pSYL105) accumulated the least amount of PHB with the lowest PHB yield at the lowest synthesis rate. JM109 (pSYL105) accumulated PHB to the highest extent (85.6%) with relatively low true cell mass (0.77 g/L). Considerable filamentation of cells accumulating PHB was observed for all strains except for K12 and W, which seemed to be due either to the overexpression of the foreign PHA biosynthesis enzymes or to the accumulation of PHB.

A clinical rationale for assessing rapid automatized naming in children with language disorders

Three continuous rapid naming tasks (Semel, Wiig, & Secord, 1995) were administered to 2,450 American, English-speaking, academically achieving individuals with typical language development and intellectual ability (ages 6 to 21 years) and 136 individuals with primary language disorders (LD; ages 6, 7, 9, 11, 12, 15-16). Naming time in seconds differed significantly (p < .01) between the groups for color naming (Task 1) at age 12, shape naming (Task 2) at age 6, and color-shape naming (Task 3) at ages 6, 7, 9, and 12. Naming accuracy did not differ significantly (p > .01) between groups at the majority of the age levels compared. In the normative group, naming speed increased with age in a monotonic progression. The developmental trajectory in the LD group was essentially parallel, but elevated. The percentages of individuals who failed the naming-time criteria for Task 3 (color-shape naming) differed significantly in the two groups at all ages compared (p < .05). These findings indicate that the requirements for two-dimensional, continuous naming (Task 3 color-shape naming) resulted in reduced naming speed (longer total times) and interference with fluency in language production in about half of the clinical sample.

Thiopentone levels during cardiopulmonary bypass. Changes in plasma protein binding during continuous infusion

Plasma total and unbound concentrations of thiopentone were investigated during exponentially decreasing infusions in seven patients undergoing cardiopulmonary bypass. Total plasma thiopentone concentrations reached a plateau (10.2, SD 2.1 micrograms/ml) soon after the initial bolus dose and commencement of the infusion. Concentrations were maintained until the onset of cardiopulmonary bypass, whereupon total plasma thiopentone concentration fell abruptly to 50.0 (SD 5.8) percent of the prebypass level. The unbound fraction of thiopentone increased from 16.6 (SD 1.9) percent before bypass to a maximum of 29.3 (SD 5.6) percent during bypass (p less than 0.01), decreased to 22.9 (SD 3.3) percent at the end of bypass (p less than 0.01), but was still elevated 5-7 hours later (20.5, SD 2.5 percent). The result of the changes in binding was a smaller decline in unbound thiopentone concentration at the onset of bypass to 76.4 (SD 15.7) percent of the prebypass level. Also, unbound levels returned to the prebypass level by the end of bypass, whereas total levels remained low.

Pentobarbitone formation during thiopentone infusion

The plasma concentrations and elimination half-life of pentobarbitone were determined in 14 surgical patients receiving a continuous, exponentially decreasing, infusion of thiopentone (mean total dose, 1.05 g; SD 0.34; mean duration of infusion 2.4 hours, SD 0.7) as the primary anaesthetic agent. The plasma pentobarbitone concentration increased gradually, to reach a maximum of 1.49 micrograms/ml (SD 0.61) at the end of the thiopentone infusion, which was 15.5 per cent (SD 6.04) of the plasma thiopentone concentration. The elimination half-life of pentobarbitone measured over the following 70 hours in nine of the patients was 34.3 hours (SD 8.2), which is within the range of values reported previously in several studies in which pentobarbitone was administered directly to volunteers. It was concluded that the formation of this active metabolite during 2-3 hour thiopentone infusions was unlikely to be of clinical relevance, but that significant concentrations may occur with longer thiopentone infusions.

Evaluation of infusion regimens for thiopentone as a primary anaesthetic agent

Several multi-stage infusion regimens and a computer controlled exponentially decreasing infusion regimen were evaluated in twelve patients undergoing head and neck surgery or neurosurgery. Thiopentone dosage was based on the mean of pharmacokinetic parameter values from the literature and adjusted for each patient's lean body mass in order to rapidly achieve a predetermined plasma thiopentone concentration of 15 or 20 micrograms/ml in the period following the initial bolus dose to induce anaesthesia. Anaesthesia was satisfactory in all cases. Plasma thiopentone concentrations were maintained between 10-20 micrograms/ml during infusion in the five patients who received either a four or five stage infusion and in the six patients who received the exponential infusion, but not in the single patient who received a two-stage infusion. The mean recovery time was 111 min. The plasma concentrations of total and unbound thiopentone at awakening showed little intersubject variability, despite considerable differences in total dose and duration of infusion, suggesting the absence of acute tolerance to the drug. Plasma clearance of total thiopentone correlated strongly with calculated lean body mass and to a lesser extent with total body weight suggesting that lean body mass, in particular, should be an accurate predictor of thiopentone maintenance dose requirements. This study shows that it is feasible to use thiopentone as a primary anaesthetic agent during surgery by administering the drug either as an exponentially decreasing infusion or as an infusion comprising 4 or 5 stepwise decreasing rates.