Comparison between parameters of muscle performance and inflammatory biomarkers of non-sarcopenic and sarcopenic elderly women

Background

Sarcopenia is a multifactorial geriatric syndrome with complex interrelationships. Increased plasma levels of inflammatory mediators increase the catabolic stimuli of the musculature, thereby causing a decrease in mass and muscular function.

Objective

The objective of this study was to compare the performance of the knee extensors test (by isokinetic dynamometer) and plasma levels of interleukin-6 (IL-6) and soluble receptors of tumor necrosis factor alpha (sTNFR1) between sarcopenics and non-sarcopenics community-dwelling elderly women residents of Brazil.

Material and methods

The diagnosis of sarcopenia included measurements of body composition (by densitometry with dual energy source of X-ray), handgrip strength (by Jamar^® dynamometer), and the usual gait velocity according to the recommendations of the European Working Group on Sarcopenia in Older People. In both sarcopenics and non-sarcopenics elderly women, we evaluated the muscle function by knee extensors test (using an isokinetic dynamometer Byodex System 4 Pro^®) at angular speeds of 60°/s and 180°/s) and also we evaluated the plasma concentrations of IL-6 and sTNFR1. Comparisons of muscle performance between groups were carried out using mixed factorial ANOVA with post hoc Bonferroni test; sTNFR1 and IL-6 variables were analyzed by applying Mann–Whitney U test.

Results

Statistical differences were observed between groups regarding muscle power (P=0.01), total work adjusted to body weight (P=0.01) at a rate of 180°/s, and plasma levels of sTNFR1 (P=0.01).

Conclusion

Sarcopenic elder women showed lower performance of the lower limbs, especially at a higher speed, predisposing these older women to greater vulnerability in functional activities that require agility and postural stability. Plasma levels of sTNFR1 were higher for non-sarcopenics elderlies. However, due to the observational nature of the study, it was impossible to infer causality among the variables surveyed.

Pulmonary actinomycosis masquerading as lung cancer: A case report

Pulmonary actinomycosis is a rare yet important and challenging diagnosis to make. It is commonly confused with other lung diseases, such as tuberculosis and bronchogenic carcinoma, leading to delay diagnosis or misdiagnosis. A 49-year-old man presented with a chronic cough, hemoptysis, and pleuritic chest pain. His initial imaging studies including computed tomography (CT) was suggestive of bronchogenic carcinoma. A subsequent CTguided biopsy was consistent with pulmonary actinomycosis and excluded the possibility of bronchogenic carcinoma. He was treated with antibiotic therapy and achieved remission with complete radiological resolution upon follow-up.

Handgrip strength is associated with, but poorly predicts, disability in older women with acute low back pain: A 12-month follow-up study

BACKGROUND

Older women with low back pain (LBP) constitute a special subpopulation at risk of severe and permanent disability. It is important to identify factors limiting functionality in this population in order to reduce costs and improve both prevention and intervention. Handgrip strength (HGS) is a biomarker of aging associated with several adverse health outcomes, but long-term associations with disability in older patients with LBP are not known.

OBJECTIVE

To examine whether HGS predicts disability in older women with acute low back pain (LBP).

METHODS

Longitudinal analyses were conducted with a sample of 135 older women from the international multicenter study Back Complaints in the Elders (BACE-Brazil). Women aged 60 years and over with a new episode of acute LBP were included. HGS was assessed with Jamar^® dynamometer, and disability was assessed using the Roland Morris questionnaire and gait speed test. Variables were assessed at baseline and at 12-month follow-up. Linear regression models explored associations between HGS and disability measures.

RESULTS

Significant association was found between HGS at baseline and gait speed at 12-month follow-up (r=-0.24; p=0.004). A multivariable-adjusted model showed that this association was independent of age, body mass index, and pain intensity (adjusted R²=0.13; p<0.001). A final prediction model showed an incremental difference of only 2.1% in gait speed after inclusion of HGS as an independent variable. No association was found between HGS and score on the Roland Morris questionnaire.

CONCLUSION

Caution is needed regarding the use of HGS as a predictive measure of disability in older women with acute LBP. Changes in gait speed were very small and unlikely to be of clinical relevance.

Brain-derived neurotrophic factor plasma levels are increased in older women after an acute episode of low back pain

BACKGROUND

Low back pain (LBP) is a growing public health problem in old age, and it is associated with disabling pain and depressive disorders. We compared brain-derived neurotrophic factor (BDNF) plasma levels, a key neurotrophin in pain modulation, between older women after an acute episode of LBP and age-matched pain-free controls, and investigated potential differences in BDNF levels between controls and LBP subgroups based on pain severity, presence of depressive symptoms and use of analgesic and antidepressant drugs.

METHODS

A total of 221 participants (154 with LBP and 67 pain-free) were studied. A comprehensive assessment of sociodemographic and clinical variables was conducted including pain severity (11-point NRS), depressive symptoms (GDS-15), age, body mass index, physical activity and total number of comorbidities and medications in use.

RESULTS

BDNF levels in LBP group were significantly higher than controls (7515.9±3021.2; Md=7116.0 vs 6331.8±3364.0; Md=5897.5pg/mL, P=0.005). LBP subgroups exhibited higher BDNF levels than controls, regardless of pain severity, presence of depressive symptoms and use of analgesic drugs. BDNF levels were significantly higher in LBP subgroup without use of antidepressant drugs compared to both controls and LBP subgroup with use of antidepressant drugs.

DISCUSSION

This study provides evidence that older women with acute low back pain exhibit higher BDNF plasma levels compared to pain-free controls. Subgroup comparisons suggest that use of pain-relief drugs may influence BDNF levels. The study results offer a novel target for research on mechanisms of back pain in older adults.

Functional performance and plasma cytokine levels in elderly women with and without low back pain

BACKGROUND AND OBJECTIVES

Low back pain (LBP) is a complaint of great importance among the elderly due to its significant impact on function. LBP could contribute to changes in the regulatory process of inflammatory mediators observed in elders. The aim of this study was to compare plasma levels of interleukin(IL)-6, soluble tumor necrosis factor receptor 1(sTNF-R1), and functionality among 3 groups of elderly women: GI, with LBP; GII, without LBP but reports of other pain; and GIII, without any reported pain.

MATERIAL AND METHOD

This was an observational study of a subsample of the international Back Complaints in the Elders cohort study. IL-6 and sTNF-R1 were measured using the enzyme-linked immunosorbent assay. Functionality was assessed using the Timed Up and Go, gait speed and Roland Morris Disability Questionnaire; and pain, using the numerical pain scale.

RESULTS

Two hundred and thirteen women aged 71.35 ± 4.76 years were included. GI presented the highest sTNF-R1 levels (p=0.016), worst TUG performance (p< 0.001) and slowest gait speed (p< 0.01) compared to GII and GIII, which were similar (p > 0.05). No difference was found between the IL-6 plasma levels in any of the groups.

CONCLUSION

Elderly women with LBP had the highest sTNF-R1 plasma levels and the worst functional performance compared to elderly women with reports of other pain (not LBP) or no pain.

The geriatric depression scale and the timed up and go test predict fear of falling in community-dwelling elderly women with type 2 diabetes mellitus: a cross-sectional study

Background

Fear of falling is a common and potentially disabling problem among older adults. However, little is known about this condition in older adults with diabetes mellitus. The aims of this study were to investigate the impact of the fear of falling on clinical, functional and gait variables in older women with type 2 diabetes and to identify which variables could predict the fear of falling in this population.

Methods

Ninety-nine community-dwelling older women with type 2 diabetes (aged 65 to 89 years) were stratified in two groups based on their Falls Efficacy Scale-International score. Participants with a score < 23 were assigned to the group without the fear of falling (n = 50) and those with a score ≥ 23 were assigned to the group with the fear of falling (n = 49). Clinical data included demographics, anthropometrics, number of diseases and medications, physical activity level, fall history, frailty level, cognition, depressive symptoms, fasting glucose level and disease duration. Functional measures included the Timed Up and Go test (TUG), the five times sit-to-stand test (5-STS) and handgrip strength. Gait parameters were obtained using the GAITRite® system.

Results

Participants with a fear of falling were frailer and presented more depressive symptoms and worse performance on the TUG and 5-STS tests compared with those without a fear of falling. The group with the fear of falling also walked with a lower velocity, cadence and step length and increased step time and swing time variability. The multivariate regression analysis showed that the likelihood of having a fear of falling increased 1.34 times (OR 1.34, 95 % CI 1.11–1.61) for a one-point increase in the Geriatric Depression Scale (GDS-15) score and 1.36 times (OR 1.36, 95 % CI 1.07–1.73) for each second of increase in the TUG performance.

Conclusions

The fear of falling in community-dwelling older women with type 2 diabetes mellitus is associated with frailty, depressive symptoms and dynamic balance, functional mobility and gait deficits. Furthermore, both the GDS-15 and the TUG test predict a fear of falling in this population. Therefore, these instruments should be considered during the assessment of diabetic older women with fear of falling.

Concept of family insufficiency in the aged: critical literature analysis

OBJECTIVE

to identify the attributes of the "family insufficiency" concept of the aged in the literature.

METHOD

critical literature analysis.

RESULTS

family insufficiency is characterized as a complex process of psychosocial interaction, founded mainly on low social support of the aged and impaired family ties. Its antecedents are found in contemporary transformations within the family system, intergenerational conflicts, impaired family relationships and social vulnerability of the family. The consequences of family insufficiency include social vulnerability of the aged, decline of psychological and functional health, lower quality of life and unsuccessful aging. An original theoretical proposal was elaborated for the concept of family insufficiency in the elderly, with the identification of its attributes, antecedents and consequences.

CONCLUSION

the findings of this study constitute a theoretical advancement in the Family Insufficiency Syndrome in elderly people and provide data for future field research in developing the concept.

Adherence of older women with strength training and aerobic exercise

Background

Participation of older people in a program of regular exercise is an effective strategy to minimize the physical decline associated with age. The purpose of this study was to assess adherence rates in older women enrolled in two different exercise programs (one aerobic exercise and one strength training) and identify any associated clinical or functional factors.

Methods

This was an exploratory observational study in a sample of 231 elderly women of mean age 70.5 years. We used a structured questionnaire with standardized tests to evaluate the relevant clinical and functional measures. A specific adherence questionnaire was developed by the researchers to determine motivators and barriers to exercise adherence.

Results

The adherence rate was 49.70% in the aerobic exercise group and 56.20% in the strength training group. Multiple logistic regression models for motivation were significant (P=0.003) for the muscle strengthening group (R²=0.310) and also significant (P=0.008) for the aerobic exercise group (R²=0.154). A third regression model for barriers to exercise was significant (P=0.003) only for the muscle strengthening group (R²=0.236). The present study shows no direct relationship between worsening health status and poor adherence.

Conclusion

Factors related to adherence with exercise in the elderly are multifactorial.

TNF-α, IL6, and IL10 polymorphisms and the effect of physical exercise on inflammatory parameters and physical performance in elderly women

High levels of inflammatory mediators are associated with reduced physical capabilities and muscle function in the elderly. Single nucleotide polymorphisms (SNPs) may affect the expression and synthesis of these molecules, thus influencing the intensity of the inflammatory response and susceptibility to certain diseases. Physical exercise may attenuate age-related chronic inflammation and improve physical performance. This study evaluated the interaction between the SNP rs1800629 in TNF-α, rs1800795 in IL6, and rs1800896 in IL10 and the effect of physical exercise on physical performance and inflammation in elderly women. There was a significant interaction between rs1800629 and the effect of exercise on physical performance and between the combined 3-SNP genotype and changes in physical performance in response to exercise. These SNPs did not influence the effect of exercise on inflammatory parameters. Elderly women with a combination of genotypes associated with an anti-inflammatory profile (low TNF-α and IL-6 production, high IL-10 production) showed better physical performance independent of exercise modality, evidence of an interactive influence of genetic and environmental factors on improving physical performance in elderly women.

Poor correlation between handgrip strength and isokinetic performance of knee flexor and extensor muscles in community-dwelling elderly women

AIM

To investigate the correlation between handgrip strength and performance of knee flexor and extensor muscles determined using an isokinetic dynamometer in community-dwelling elderly women.

METHODS

This was a cross-sectional study. Sample selection for the study was made by convenience, and 221 (71.07 ± 4.93 years) community-dwelling elderly women were included. Knee flexor and extensor muscle performance was measured using an isokinetic dynamometer Biodex System 3 Pro. The isokinetic variables chosen for analysis were peak torque, peak torque/bodyweight, total work/bodyweight, total work, average power, and agonist/antagonist ratio at the angular velocities of 60°/s and 180°/s. Assessment of handgrip strength was carried out using the Jamar dynamometer. Spearman's correlation coefficient was calculated to identify intervariable correlations.

RESULTS

Only knee flexor peak torque (60°/s) and average power (60°/s), and knee extensor peak torque (180°/s) and total work (180°/s) were significantly (P < 0.05), yet poorly, correlated with handgrip strength (r < 0.30).

CONCLUSION

The majority of analyses did not show any correlation between variables assessed by isokinetic dynamometer and handgrip dynamometer. Caution is required when generalizing handgrip strength as a predictor of global muscle strength in community-dwelling elderly women.

Impact of an exercise program on muscular and functional performance and plasma levels of interleukin 6 and soluble receptor tumor necrosis factor in prefrail community-dwelling older women: a randomized controlled trial

OBJECTIVE

To examine the impact of a muscle resistance program (MRP) on muscular and functional performance and on interleukin 6 (IL-6) and soluble tumor necrosis factor receptor-1 (sTNFr1) plasma levels in prefrail community-dwelling women.

DESIGN

Randomized controlled trial crossover design with a postintervention and short-term follow-up.

SETTING

University hospital.

PARTICIPANTS

Prefrail community-dwelling women (N=32; ≥65y).

INTERVENTION

The MRP was designed based on the exercise at 75% of each participant's maximum load (10wk, 3 times/wk).

MAIN OUTCOME MEASURES

Plasma concentrations of IL-6 and sTNFr1 (high-sensitivity enzyme-linked immunosorbent assay kits), muscle strength of the knee extensors (isokinetic), and functional performance (Timed Up & Go [TUG] test and 10-meter walk test [10MWT]).

RESULTS

There were significant differences in functional and muscular performance between the pre-MRP, post-MRP, and 10-week follow-up period. After the MRP, both functional (TUG, pre-MRP=11.1s vs post-MRP=10.4s, P=.00; 10MWT, pre-MRP=4.9s vs post-MRP, 4.4s, P=.00) and muscular performances (pre-MRP=77.8% and post-MRP=83.1%, P=.02) improved. After cessation of the MRP (follow-up period), sTNFr1 plasma levels increased by 21.4% at 10-week follow-up (post-MRP, 406.4pg/mL; 10-week follow-up, 517.0pg/mL; P=.03). There were significant differences in sTNFr1 (P=.01).

CONCLUSIONS

The MRP was effective in improving functional and muscular performances, although alterations in plasma levels of IL-6 and sTNFr1 could not be identified after the MRP. Cessation of the MRP after 10 weeks resulted in increased plasma levels of sTNFr1.

Avaliação da capacidade funcional em idosos diabéticos

O diabetes mellitus (DM) tem associação com várias comorbidades que comprometem ainda mais a funcionalidade do idoso. Essa doença crônica está vinculada ao risco de incapacidade para realizar atividades rotineiras. O objetivo deste estudo foi comparar a capacidade funcional de idosos diabéticos e não diabéticos. Trata-se de uma pesquisa observacional transversal que avaliou 40 idosos, divididos em dois grupos, sendo 20 diabéticos (71,1±4,6 anos) e 20 não diabéticos (71,7±4,4 anos). Os grupos foram semelhantes quanto ao gênero, idade e índice de massa corpórea (IMC). Para avaliação da capacidade funcional foram realizados o teste de desempenho físico modificado (TDMF) e o teste de caminhada de seis minutos (TC6). A percepção subjetiva do esforço foi avaliada por meio da escala de Borg modificada e o teste de sensibilidade pela percepção de um conjunto de seis monofilamentos de náilon de Semmes-Weinstein. Os dados foram analisados por meio do Mann-Whitney test. O grupo de idosos diabéticos percorreu menor distância no TC6 (396±55,6x481,5±73,1 m; p=0,0003) e apresentou pior teste de sensibilidade quando comparado com os não diabéticos, mas nenhuma diferença foi encontrada no TDMF. Os idosos diabéticos relataram pior aptidão física quando comparados com os não diabéticos.

Muscle strength, muscle balance, physical function and plasma interleukin-6 (IL-6) levels in elderly women with knee osteoarthritis (OA)

An increased circulating level of inflammatory cytokines has been associated with sarcopenia, functional disability, chronic diseases, and mortality in the elderly. Osteoarthritis (OA) is a disease common to this population, the seriousness of articular degeneration has been associated to the increase in some cytokines, IL-6 among them. The aim of the present study was to correlate IL-6 plasma levels with muscle strength, endurance, muscle balance hamstring/quadriceps (H/Q) and physical function in 80 elderly women (71.2 ± 5.3) with knee OA. IL-6 was measured using enzyme-linked immunosorbent assay (ELISA). Quadriceps and hamstring muscle strength, endurance and hamstring-quadriceps muscle balance were assessed using a Biodex system 3 pro(®) isokinetic dynamometer. Physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Spearman's correlation coefficient was used to explore the relationship between the outcomes at the significance level of α=0.05. IL-6 was inversely correlated to the endurance of the hamstring muscles (r=-0.232; p=0.03) and muscle balance (H/Q) on the lower right side at 180°/s (r=-0.254; p=0.023). No significant correlation between IL-6, muscle strength and physical function was found. Our results show that elevated levels of IL-6 may possibly contribute to the reduction of the endurance of hamstring muscles and H/Q muscle balance in the elderly studied.

Physical therapy intervention (PTI) increases plasma brain-derived neurotrophic factor (BDNF) levels in non-frail and pre-frail elderly women

Biomarkers are important factors in the identification of the frail elderly (higher risk of developing disease) and in assessing the impact of PTI. On the other hand, BDNF has been related to neuroprotection in a series of central nervous system diseases in older age. The levels of BDNF in groups of elderly women classified according to Fried phenotype (non-frail and pre-frail) were compared. We assessed the impact of a PTI on BDNF levels. A convenience sample of 48 elderly women was randomly selected. The PTI group was composed by 20 elderly women selected from this group. Plasma neurotrophic factors, such as BDNF, glial-derived neutrophic factor (GDNF), and nerve growth factor (NGF) were measured by enzyme-linked immunosorbent assay (ELISA). Timed-up-and-go (TUG) test, hand-grip and work/body weight were evaluated before and after the intervention. Plasma concentrations of BDNF were significantly higher in non-frail in comparison to pre-frail elderly women. After the PTI, higher levels of BDNF were found in elderly women (before 351±68 pg/ml and after 593±79 pg/ml; p<0.001). Both groups had an increase in BDNF levels after the PTI. The low levels of BDNF in pre-frail elderly women suggest that this neurotrophic factor may be a key pathophysiological mediator in the syndrome of frailty. The fact that PTI increased BDNF levels in both groups suggests that it may be possible to modify this phenotype.

Desempenho muscular, dor, rigidez e funcionalidade de idosas com osteoartrite de joelho

OBJETIVO: Verificar a correlação do desempenho dos músculos do joelho e os domínios dor, rigidez e funcionalidade do Questionário Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) de idosas com osteoartrite de joelho (OA). MÉTODOS: Estudo transversal observacional com uma amostra de 80 idosas (71,2 ± 5,3 anos) com diagnóstico clínico de OA de joelho. Força, resistência e equilíbrio musculares foram avaliados por meio do dinamômetro isocinético Biodex System 3 Pro, nas velocidades angulares de 60º/s e 180º/s; a funcionalidade, presença de dor e rigidez foram avaliadas pelo questionário WOMAC. A correlação entre as variáveis foi analisada pelo teste de Spearman. RESULTADOS: Houve correlação inversa significativa da força e resistência musculares do quadríceps (QUA) e isquiossurais (IQS) nas velocidades de 60º/s e 180°/s, respectivamente, e da relação de equilíbrio muscular IQS/QUA a 180°/s com todos os domínios do WOMAC (p<0.05). CONCLUSÕES: A redução da força e da resistência e a presença de desequilíbrio dos músculos do joelho correlacionaram-se inversamente com todos os domínios do WOMAC, apontando para a necessidade de intervenções que envolvam um trabalho de fortalecimento, resistência e equilíbrio muscular de extensores e flexores de joelho, visando a redução do impacto da OA na dor, rigidez e funcionalidade do idoso. Nivel de Evidência I, Estudos diagnósticos, Investigação de um exame para diagnóstico.

Interleukin-6 plasma levels and socioeconomic status in Brazilian elderly community-dwelling women

Aging is related to a chronic increase in inflammatory cytokines. Adverse socioeconomic conditions are associated with increased plasma levels of these molecules, especially interleukin (IL)-6. Considering the differential profile of elderly Brazilians regarding their socioeconomic and cultural aspects, the objectives of this study were: to assess the correlation and differences between levels of IL-6 and socioeconomic status (education and income) in elderly women. IL-6 levels were measured using ELISA. The Spearman test was used to determine the correlation between IL-6 and socioeconomic status, and the Kruskal-Wallis and Mann-Whitney tests for cytokine level differences across education and income. IL-6 showed a significant inverse correlation with education (r = -0.205, p = 0.014) and income (r = -0.185, p = 0.028). Differences in IL-6 levels were registered across the education variables. The results corroborate evidence that low socioeconomic status is related to higher IL-6 plasma levels in elderly women.

Influence of socio-demographic, clinical and functional factors on the severity of dementia

Dementia is one of the most relevant illnesses due to its functional impact on the elderly. The aim of the present study was to determine the influence of socio-demographic, clinical, cognitive and functional factors on the severity of dementia in elderly individuals. One hundred six elderly individuals with a diagnosis of dementia as determined by the DSM-IV/APA participated in the study. Cognition was assessed by the mini-mental state examination (MMSE); functional performance of basic and instrumental activities of daily living (BADLs and IADLs) was assessed by the Katz index (KI), Lawton-Brody index (LBI) and Pfeffer index (PI). The severity of dementia was established through the clinical dementia rating (CDR). In order to determine the influence of factors on the degree of dementia, ordinal regression analysis was performed. Age, MMSE, KI, LBI and PI scores had statistically significant associations to the severity of dementia. However, only the age (odds ratio (OR) = 0.197; confidence interval (CI) = 0.060-0.643) and performance in IADLs (LBI: OR = 1.237, CI = 1.077-1.422; PI: OR = 0.641, CI = 0.548-0.750) were maintained in the final ordinal regression model, R(2) = 0.818. The results show that elderly individuals over 80 years of age and those with a more compromised performance in IADLs have a greater chance of exhibiting more severe degrees of dementia. These findings suggest that the ability to perform IADLs may be an important variable in differentiating degrees of the severity of dementia.

Adaptação transcultural e análise da confiabilidade do Southampton Assessment of Mobility para avaliar a mobilidade de idosos brasileiros com demência

O objetivo deste trabalho foi adaptar transculturalmente o instrumento Southampton Assessment of Mobility e testar sua confiabilidade intra e interexaminadores para idosos brasileiros da comunidade, com demência, classificados quanto à gravidade pelo Clinical Dementia Rating. O instrumento adaptado foi aplicado em uma amostra de 107 idosos (76,26 anos ± 7,59; 27,1% homens, 72,9% mulheres) com diagnóstico clínico de demência dado pelo serviço de geriatria do Centro de Referência em Atenção ao Idoso Professor Caio Benjamin Dias, do Estado de Minas Gerais, Hospital das Clínicas, Universidade Federal de Minas Gerais, Minas Gerais, Brasil. Dentre os avaliados, 39 (76,85 anos ± 7,75; 23,1% homens, 76,9% mulheres) foram aleatorizados para avaliação da confiabilidade. A ferramenta estatística foi o teste kappa. Os resultados mostraram que a confiabilidade intra e interexaminadores foram, respectivamente: demência leve 0,89-0,86; moderada 0,79-0,85 e grave 0,53-0,49. O instrumento adaptado demonstrou ser aplicável à população alvo e demonstrou ter confiabilidade "quase perfeita" para demência leve e moderada. Para a demência grave os índices de confiabilidade foram "moderados".

Transduction of human CD34+ CD38- bone marrow and cord blood-derived SCID-repopulating cells with third-generation lentiviral vectors

The major limitations of Moloney murine leukemia virus (MoMLV)-based vectors for human stem cell applications, particularly those requiring bone marrow (BM) stem cells, include their requirement for mitosis and retroviral receptor expression. New vectors based upon lentiviruses such as HIV-1 exhibit properties that may circumvent these problems. We report that novel third-generation, self-inactivating lentiviral vectors, expressing enhanced green fluorescent protein (EGFP) and pseudotyped with vesicular stomatitis virus G glycoprotein (VSV-G), can efficiently transduce primitive human repopulating cells derived from human BM and cord blood (CB) tested by the SCID-repopulating cell (SRC) assay. Highly purified CD34+ CD38- CB or BM cells were efficiently transduced (4-69%) and stably expressed in EGFP for 40 days in culture following infection for only 24 h without fibronectin, polybrene, or cytokines. Nonobese diabetic/severe combined immune-deficient (NOD/SCID) mice transplanted with transduced cells from either CB or BM donors were well engrafted, demonstrating maintenance of SRC during the infection procedure. Serially obtained femoral BM samples indicated that the proportion of EGFP+ cells within both myeloid and lymphoid lineages was maintained or even increased over time, averaging 42.3 +/- 6.6% for BM donors and 23.3 +/- 7.2% for CB at 12 weeks. Thus, the third-generation lentivectors readily transduce human CB and BM stem cells, under minimal conditions of ex vivo culture, where MoMLV-based vectors are ineffective. Since CB is inappropriate for most therapeutic applications, the efficient maintenance and transduction of BM-derived SRC during the short infection procedure are notable advantages of lentivectors.

Expansion of human cord blood CD34(+)CD38(-) cells in ex vivo culture during retroviral transduction without a corresponding increase in SCID repopulating cell (SRC) frequency: dissociation of SRC phenotype and function

Current procedures for the genetic manipulation of hematopoietic stem cells are relatively inefficient due, in part, to a poor understanding of the conditions for ex vivo maintenance or expansion of stem cells. We report improvements in the retroviral transduction of human stem cells based on the SCID-repopulating cell (SRC) assay and analysis of Lin(-) CD34(+)CD38(-) cells as a surrogate measure of stem cell function. Based on our earlier study of the conditions required for ex vivo expansion of Lin(-)CD34(+) CD38(-) cells and SRC, CD34(+)-enriched lineage-depleted umbilical cord blood cells were cultured for 2 to 6 days on fibronectin fragment in MGIN (MSCV-EGFP-Neo) retroviral supernatant (containing 1.5% fetal bovine serum) and IL-6, SCF, Flt-3 ligand, and G-CSF. Both CD34(+)CD38(-) cells (20.8%) and CFC (26.3%) were efficiently marked. When the bone marrow of engrafted NOD/SCID mice was examined, 75% (12/16) contained multilineage (myeloid and B lymphoid) EGFP(+) human cells composing as much as 59% of the graft. Half of these mice received a limiting dose of SRC, suggesting that the marked cells were derived from a single transduced SRC. Surprisingly, these culture conditions produced a large expansion (166-fold) of cells with the CD34(+)CD38(-) phenotype (n = 20). However, there was no increase in SRC numbers, indicating dissociation between the CD34(+)CD38(-) phenotype and SRC function. The underlying mechanism involved apparent downregulation of CD38 expression within a population of cultured CD34(+)CD38(+) cells that no longer contained any SRC function. These results suggest that the relationship between stem cell function and cell surface phenotype may not be reliable for cultured cells. (Blood. 2000;95:102-110)

Characterization and retroviral transduction of an early human lymphomyeloid precursor assayed in nonswitched long-term culture on murine stroma

In the hierarchy of human hematopoietic progenitors, long-term culture-initiating cells (LTC-IC) and extended LTC-IC belong to the earliest cell populations that can be assayed in vitro. We report the identification of a multipotential lymphomyeloid progenitor detected in a nonswitch culture system. We observed the emergence of CD33+ myeloid and CD19+ B-lymphoid cells following plating of lineage-depleted (Lin-) CD34 -enriched or purified CD34+ CD38- cord blood cells on MS-5 stroma in the absence of exogenous cytokines. Both CD19+ CD20- pro-B and CD19+ CD20+ pre-B lymphocytes coexist with myeloid cells in long-term culture. A limiting dilution approach was used to show that a single CD34+ CD38- cell can generate lymphomyeloid progeny in conventional (5-week) and extended (10-week) cultures. Most of the clones in long-term culture or extended long-term culture contained not only lymphoid and myeloid cells, but also myeloid clonogenic progenitors. A high proportion of CD34+ CD38- cells gave rise to lymphomyeloid clones after 5 and 10 weeks of culturing (up to 48% and 16%, respectively), which distinguishes the assay reported here from those using switch culture conditions. We performed retroviral gene transfer experiments involving 1-3 days of exposure of Lin CD34+ -enriched cells to virus encoding enhanced green fluorescent protein. Monitoring of gene transfer efficiency into LTC-IC by enhanced green fluorescent protein fluorescence showed that it is possible to achieve marking of lymphomyeloid LTC-IC, albeit to a lesser extent than myeloid-restricted LTC-IC.

Development of a novel osteochondral graft for cartilage repair

This study reports the development of a novel osteochondral graft for cartilage repair. A technique of proteoglycan extraction via timed enzymatic digestion with hyaluronidase and trypsin and subsequent processing with a chloroform-methanol solution to remove cellular debris from a fresh-frozen bovine osteochondral sample is a method described to prepare a stable biological carrier of low immunogenicity. Lyophilization of the carrier followed by rehydration in a suspension of lapine chondrocytes produced a chimeric xenograft that succeeded in vivo in enhancing cartilage repair. In a pilot study, full-thickness articular cartilage defects treated with these xenografts demonstrated improved healing compared to untreated defects or defects treated with unseeded grafts at 2, 6, and 12 weeks postimplantation. The xenograft provoked a mild inflammatory response; however this did not impede the repair process. Further investigation of this novel chimeric xenograft eventually may yield a method of cartilage repair superior to current methods of treatment.

Retroviral transduction of TLS-ERG initiates a leukemogenic program in normal human hematopoietic cells

Many chimeric oncogenes have been identified by virtue of the association between chromosomal translocation and specific human leukemias. However, the biological mechanism by which these oncogenes disrupt the developmental program of normal human hematopoietic cells during the initiation of the leukemogenic process is poorly understood due to the absence of an appropriate experimental system to study their function. Here, we report that retroviral transduction of TLS-ERG, a myeloid leukemia-associated fusion gene, to human cord blood cells results in altered myeloid and arrested erythroid differentiation and a dramatic increase in the proliferative and self-renewal capacity of transduced myeloid progenitors. Thus, TLS-ERG expression alone induced a leukemogenic program that exhibited similarities to the human disease associated with this translocation. These results provide an experimental examination of the early stages of the human leukemogenic process induced by a single oncogene and establish a paradigm to functionally assay putative leukemogenic genes in normal human hematopoietic cells.