Caffeine and 3-km cycling performance: Effects of mouth rinsing, genotype, and time of day.

We assessed the efficacy of caffeine mouth rinsing on 3-km cycling performance and determined whether caffeine mouth rinsing affects performance gains influenced by the CYP1A2 polymorphism. Thirty-eight recreational cyclists completed four simulated 3-km time trials (TT). Subjects ingested either 6 mg/kg BW of caffeine or placebo 1 h prior to each TT. Additionally, 25 mL of 1.14% caffeine or placebo solution were mouth rinsed before each TT. The treatments were Placebo, caffeine Ingestion, caffeine Rinse and Ingestion+Rinse. Subjects were genotyped and classified as AA homozygotes or AC heterozygotes for the rs762551 polymorphism of the CYP1A2 gene involved in caffeine metabolism. Magnitude-based inferences were used to evaluate treatment differences in mean power output based on a predetermined meaningful treatment effect of 1.0%. AC heterozygotes (4.1%) and AA homozygotes (3.4%) benefited from Ingestion+Rinse, but only AC performed better with Ingestion (6.0%). Additionally, Rinse and Ingestion+Rinse elicited better performance relative to Placebo among subjects that performed prior to 10:00 h (Early) compared with after 10:00 h (Late). The present study provides additional evidence of genotype and time of day factors that affect the ergogenic value of caffeine intake that may allow for more personalized caffeine intake strategies to maximize performance.

Predictors of contact tracing completion and outcomes in tuberculosis: a 21-year retrospective cohort study.

SETTING: Birmingham, UK, 1990-2010. OBJECTIVE: To identify predictors in contacts for completion of screening and of a positive screening outcome, i.e., a diagnosis of latent tuberculous infection (LTBI) or active tuberculosis (TB). DESIGN: A retrospective cohort study of TB notifications for a European city. RESULTS: A total of 46,158 contacts were identified from 7365 index cases. Over the study period 17,471 (40.9%) failed to complete screening. Active TB or LTBI was diagnosed in 2220 (7.0%) contacts of cases of pulmonary TB (PTB) and in 222 (2.7%) contacts of cases of extra-pulmonary TB (EPTB). The proportion of contacts offered LTBI treatment increased (P < 0.001) over the study period. Age, ethnicity, sex and use of interferon-gamma release assays (IGRA) were the most important predictors of screening completion, with working age adult males who were Black or from the Indian subcontinent least likely to complete. Age, smear positivity status of the index case and IGRA usage were the most important predictors of a positive screening outcome (active TB or LTBI diagnosed). CONCLUSION: Contact tracing of both PTB and EPTB index cases is useful for active case finding. The findings of this study can be used to target screening and improve the effectiveness and efficiency of local contact tracing programmes.

Oral function and diet quality in a community-based sample.

Overall diet quality indices, such as the Healthy Eating Index (HEI), are preferred for epidemiological studies, yet studies in dentistry have focused on isolated dietary components. This study investigated the influence of socio-demographic and masticatory variables (masticatory performance, bite force, number of posterior functional tooth units, TMJ disorder, and dentition status) on overall diet quality in a community-based sample (n = 731). Cross-sectional data were derived from clinical examinations, bite force recordings, masticatory performance measurements, and two 24-hour dietary recalls. Females, European-Americans, and older subjects had better HEI scores than males, Mexican-Americans, and younger subjects, respectively. Income, education, and the masticatory variables were not related to diet quality. Analyses according to dentition status (good dentition, compromised dentition, partial denture, and complete dentures) showed no inter-group differences for HEI except for the age groups. The results suggest that the chewing-related factors evaluated in this sample are not predictors of overall diet quality across the socio-demographic groups.

Is use of exogenous estrogen associated with temporomandibular signs and symptoms?

BACKGROUND: Studies of historical data suggest a link between exogenous estrogen use and referral for treatment for temporomandibular disorders, or TMDs. The purpose of the authors' study was to determine the association between exogenous estrogen use and signs and symptoms of TMD assessed by direct physical examination in a randomly selected community sample of primarily postmenopausal women. METHODS: A calibrated clinical examiner examined a stratified random sample of 510 women aged 37 to 82 years using the Craniomandibular Index, or CMI. All medications that subjects were taking at the time of the examination were identified by interview and examination of subjects' medication containers on two occasions. One hundred seventy-four subjects were taking medications containing estrogen, and 336 were taking no such medications. RESULTS: The muscle and joint signs and symptoms of women taking and not taking estrogen were not significantly different after the authors controlled for sociocultural, demographic and health care utilization variables. Estrogen use also failed to distinguish women receiving relatively high and low scores on the CMI. CONCLUSION: Estrogen replacement therapy does not place women at increased risk of developing TMDs. CLINICAL IMPLICATIONS: Clinicians need not be concerned that patients taking oral contraceptives or replacement estrogens are at increased risk of developing TMDs.

Muscularity and the density of the fat-free mass in athletes.

The purpose of this study was to use estimates of body composition from a four-component model to determine whether the density of the fat-free mass (D(FFM)) is affected by muscularity or musculoskeletal development in a heterogenous group of athletes and nonathletes. Measures of body density by hydrostatic weighing, body water by deuterium dilution, bone mineral by whole body dual-energy X-ray absorptiometry (DXA), total body skeletal muscle estimated from DXA, and musculoskeletal development as measured by the mesomorphy rating from the Heath-Carter anthropometric somatotype were obtained in 111 collegiate athletes (67 men and 44 women) and 61 nonathletes (24 men and 37 women). In the entire group, D(FFM) varied from 1.075 to 1.127 g/cm3 and was strongly related to the water and protein fractions of the fat-free mass (FFM; r = -0.96 and 0.89) and moderately related to the mineral fraction of the FFM (r = 0.65). Skeletal muscle (%FFM) varied from 40 to 68%, and mesomorphy varied from 1.6 to 9.6, but neither was significantly related to D(FFM) (r = 0.11 and -0.14) or to the difference between percent fat estimated from the four-component model and from densitometry (r = 0.09 and -0.16). We conclude that, in a heterogeneous group of young adult athletes and nonathletes, D(FFM) and the accuracy of estimates of body composition from body density using the Siri equation are not related to muscularity or musculoskeletal development. Athletes in selected sports may have systematic deviations in D(FFM) from the value of 1.1 g/cm3 assumed in the Siri equation, resulting in group mean errors in estimation of percent fat from densitometry of 2-5% body mass, but the cause of these deviations is complex and not simply a reflection of differences in muscularity or musculoskeletal development.

Muscle activation and the slow component rise in oxygen uptake during cycling.

PURPOSE: During constant-rate high-intensity exercise, a steady state for oxygen uptake (VO2) is not achieved and, after the initial rapid increase, VO2 continues to increase slowly. The mechanism underlying the slow-component rise in VO2 during high-intensity exercise is unknown. It has been hypothesized that increased muscle use may be a contributing factor, but only limited electromyograph (EMG) data are available supporting this hypothesis. The purpose of this study was to determine whether there is an association between the VO2 slow component and muscle use assessed by contrast shifts in magnetic resonance images (magnetic resonance imaging (MRI)). METHODS: The VO2 slow component was measured in 16 subjects during two 15-min bouts of cycling performed at high and low intensities. EMG and MRI transverse relaxation times (T2) were obtained after 3 and 15 min to determine muscle activity at each intensity. RESULTS: Low-intensity cycling produced no VO2 slow component, and no increases in muscle activity, except for a small increase (P < 0.05) in the T2 of the vastus lateralis. During high-intensity cycling, VO2, T2 of the vastus lateralis, rectus femoris and whole leg, and EMG activity and median power frequency of the vastus lateralis rose significantly (P < 0.05) from 3 to 15 min. Percent increases in VO2 and muscle T2 were related during high-intensity cycling (r = 0.63), but not during low-intensity cycling (r = 0.00). CONCLUSION: We conclude that increased muscle use is in part responsible for the slow component rise in oxygen uptake. The results support the hypothesis that during constant-rate exercise at intensities above lactate threshold, progressively greater use of fast-twitch motor units increases energy demand and causes concomitant progressive increases in VO2 and lactate.

The role of dentistry in palliative care of the head and neck cancer patient.

Although palliative care for the terminally ill is based on a multidimensional philosophy to provide whole-person comfort care while maintaining optimal function, it does not usually include dentistry in its team approach. Dentists can have a significant role in the care of these patients by providing total, active comfort care of the oral cavity. The function of the oral cavity is essential to the patient's ability to thrive. Therefore, alleviation of pain and prevention of infection in the oral cavity should be a priority in providing total, active comfort for the patient. The oral problems experienced by the hospice head and neck patient clearly affect the quality of his or her remaining life. Through routine assessments and interventions by a dentist on the palliative care team (Figure 4), comfort care for the patient may be improved by the maintenance of oral hygiene and procedures to hydrate the oral mucosa. In addition, routine dental assessments may identify dental disease and facilitate dental interventions for caries, periodontal disease, oral mucosal problems or prosthetic needs. Attention to such detail may reduce not only the microbial load of the mouth but the risk for pain and oral infection as well. This multidisciplinary approach to palliative care, including a dentist, may reduce the oral debilities that influence the patient's ability to speak, eat or swallow. Not only does maintenance of oral health have impact on the quality of life, which is already challenged by the disease, but it also aids in the ability of patients to thrive for whatever precious time is left to them.

Effects of diet and exercise on the density and composition of the fat-free mass in obese women.

PURPOSE: The purpose of this study was to determine whether the density (D(FFM)) and composition of the fat-free mass (FFM) and the accuracy of estimates of body composition from body density (%Fat(d)) are affected by diet and exercise. METHODS: Twenty-nine obese women (body mass index (BMI) = 25.0-43.7 kg x m(-2) and %Fat(d) = 35.7-47.1%) were assigned to one of three groups: diet only (DO, N = 9); diet and aerobic exercise (DE, N = 9); or control (C, N = 11). Measures of body density by hydrostatic weighing, body water by deuterium dilution, and bone mineral by whole-body dual-energy x-ray absorptiometry, and estimates of body composition from body density and from a four-component model were obtained before and after a 16-wk diet and exercise intervention. RESULTS: Mean (+/- SD) changes in body mass were -7.2 +/- 7.4, -3.9 +/- 3.3, and +1.2 +/- 2.8 kg for the DO, DE, and C, respectively. The density and composition of the FFM did not change significantly (P > 0.05) in any of the groups. Individual changes in D(FFM) (-0.011 to +0.011 g x mL(-1)), and differences between changes in %Fat estimated using a four-component model and %Fat(d) (-2.1 to +2.7% body mass) were not related to changes in body mass (r = -0.08). Individual changes in D(FFM) were most strongly related to changes in water fraction (r = -0.95) and protein fraction (r = +0.88), and were unrelated to changes in the mineral fraction (r = +0.04) of the FFM. CONCLUSIONS: We conclude that in obese women, the density and composition of the FFM are unaltered and densitometry correctly assesses group mean changes in body composition with moderate weight loss induced by diet or diet and aerobic exercise. However, individual deviations in D(FFM) from the assumed value of 1.1 g x mL(-1) are substantial, and a multi-component model in which body water is measured is needed to accurately assess individual body composition changes resulting from diet and exercise.

Body-composition changes with diet and exercise in obese women: a comparison of estimates from clinical methods and a 4-component model.

BACKGROUND: Most methods available to clinicians for estimating body-composition changes have been validated against estimates from densitometry, based on a 2-component (fat mass and fat-free mass) model. OBJECTIVE: Estimates of changes in percentage body fat (%BF) from dual-energy X-ray absorptiometry (DXA), skinfold thicknesses (SFTs), bioelectrical impedance analysis (BIA), and body mass index (BMI; in kg/m2) were compared with estimates from a 4-component (fat, water, mineral, and protein) model (%BFd,w,m), a more accurate method. DESIGN: Determinations of body density from hydrostatic weighing, body water from deuterium dilution, bone mineral and %BF from whole-body DXA, resistance from BIA, and anthropometric measures were made in 27 obese women (BMI: 31.1 +/- 4.9) assigned to 1 of 3 groups: control (C; n = 9), diet only (DO; n = 9), or diet plus aerobic exercise (DE; n = 9). RESULTS: After the 16-wk intervention, changes in body mass (BM) averaged 0.5 +/- 2.0, -7.2 +/- 7.4, and -4.0 +/- 3.3 kg and changes in %BFd,w,m averaged 2.1 +/- 1.0%, -1.2 +/- 1.4%, and -2.4 +/- 1.6% in the C, DO, and DE groups, respectively. Compared with changes in %BFd,w,m, the errors (SD of bias) for estimates of changes in %BF by DXA, BIA, SFTs, and BMI were similar (range: +/-2.0-2.4% of BM). BIA, SFTs, and BMI provided unbiased estimates of decreases in %BFd,w,m, but DXA overestimated decreases in %BF in the DO and DE groups. CONCLUSIONS: DXA, BIA, SFTs, and BMI are comparably accurate for evaluating body-composition changes induced by diet and exercise interventions; however, small changes in %BF may not be accurately detected by these clinical methods.

Effects of hydration changes on bioelectrical impedance in endurance trained individuals.

PURPOSE: The purpose of this study was to determine how differences in hydration states and ion content of hydrating fluids affected bioelectrical impedance (BI) and hydrostatic weighing (HW) measurements. METHODS: Fifteen athletic subjects aged 19-56 yr were recruited. Relative body fat (%), fat-weight (FW), and fat-free weight (FFW) were assessed using BI and HW under normal conditions (N), hypohydration (HPO), rehydration (RHY), and superhydration (SHY) states. During the RHY and SHY trial periods, subjects were hydrated with either distilled water or an electrolyte solution (ELS). HPO and SHY levels were set at 3% of each person's normally hydrated body weight. RESULTS: Comparison between the distilled water and the ELS trials indicated that hydration solution had no effect on BI or HW. Thus, the results presented are the trial means of both hydration solutions combined. Both BI and HW were shown to be highly test-retest reliable (r-values: 0.96 and 0.99, respectively). The effects of exercise induced HPO followed by RHY on body composition values indicated that HW was very stable across measurement periods while BI was not. From N to the HPO state, BI %BF declined from 14.4 +/- 5.3% to 12.3 +/- 5.3%, respectively. After RHY, BIA %BF increased to 15.5 +/- 5.8%. Similar findings occurred when subjects were superhydrated (N-BI = 13.2 +/- 5.3%; SHY-BI = 15.4 +/- 5.6%). With a comparison of the intercepts and slopes of HW and BIA for the N and SHY states, it was clear hydration status significantly affected the intercepts (HW: 0.37 vs. BI: 1.85) and not the slopes (HW: 1.00 vs BI: 0.99). As a result, a majority of all fluid changes were interpreted as FW by BI. During HPO, 82% of the weight loss was considered FW while during RHY or SHY, 128% and 85% of the water weight regain/gain was considered FW. CONCLUSION: These results indicate that BI is not a valid technique in athletes, especially when wanting to determine body composition effects of training/detraining. This study indicates that even small fluid changes such as those that occur with endurance training may be interpreted incorrectly as changes in an athlete's body fat content.

Oral health screening guidelines for nondental health care providers.

Clues identified in oral health screening can be associated with medical conditions, medical treatments, and overall health status. Thorough oral health screening involves not only talking with the patient, but touching and exploring the mouth. Oral health screening expands the role of dietitians in improving the nutritional and dietary practices of clients.

Nutrition and oral health in the elderly.

Nutritional status of the aging patient is inextricably linked to his or her oral health. Various screening instruments make it easier for the dentist to determine the nutritional status of the patient. This article discusses several of those instruments, in addition to further consideration of the link between nutrition and oral health in the aging patient.

Assessment of Clonality and Its Relevance in Acute Myeloid Leukaemia and Bone Marrow Transplantation.

The study of clonality in females is a useful tool in assessing states of neoplastic cell expansion in myeloid malignancies and remission status after chemotherapy and bone marrow transplant. Various experimental techniques have been developed based on the Lyon Hypothesis of X chromosome inactivation in females. Specific enzymes are utilised to distinguish active from inactive X chromosomes, distinctive patterns of which are then visualised by Southern blotting or more recently PCR. A valuable contribution to the nature of myeloid malignancies has been gained by these means.

Expression of AML1/MTG8 transcripts in clonogenic cells grown from bone marrow of patients in remission of acute myeloid leukaemia with t(8;21).

Patients in long-term remission of acute myeloid leukaemia (AML) M2 with t(8;21) after chemotherapy, with or without bone marrow transplantation, are known to retain residual cells which express AML1/MTG8 transcripts in bone marrow, detectable by RT-PCR. In order to determine whether these residual cells are clonogenic, we have grown remission bone marrow samples in standard semi-solid culture and picked individual CFU-GM and BFU-E colonies which were then analysed for the expression of AML1/MTG8 transcripts using a rapid specific RT-PCR technique. Nine patients were tested in remission, six between 1 and 83 months post chemotherapy, one 103 months post autologous bone marrow transplant and one 41 months post allogeneic bone marrow transplant. One of these patients also had quantitation of AML1/MTG8 transcripts on five occasions after recovery from each course of chemotherapy and at the end of treatment. There was a significant correlation between the percentage of positive colonies and the level of AML1/MTG8 transcripts. Between two and 80 CFU-GM and between two and 21 BFU-E colonies were analysed from each patient sample: 0-23% CFU-GM and 0-17% BFU-E colonies were found to express AML1/MTG8 transcripts suggesting that these residual cells are clonogenic in vitro and that the cell of origin is a multipotent myeloid progenitor.

Expression of diverse AML1/MTG8 transcripts is a consistent feature in acute myeloid leukemia with t(8;21) irrespective of disease phase.

The (8;21) chromosomal translocation occurs in 20% of adult patients with AML M2. This translocation interrupts two genes, AML1 on chromosome 21q and MTG8 (ETO) on 8q to form a chimeric gene AML1/MTG8 on the der(8) chromosome. Recent reports have shown the presence of diverse forms of transcript for this chimeric gene. Three alternative out-of-frame transcripts have been previously demonstrated (types II, III, IV) all of which have a stop codon 3' of the runt box encoding a truncated runt polypeptide. We have characterized a novel transcript (V) which is in-frame and has a stop codon 3' to the runt box. We have examined transcript diversity in 10 AML patients with t(8;21) in remission of their disease following chemotherapy or bone marrow transplantation. Specific transcripts detected at presentation in six patients were similarly expressed during remission and at relapse in two patients; thus expression of transcript diversity was unaffected by the disease phase. Alternative transcripts were unhelpful as a marker of remission quality or predictor of relapse. The significance of these diverse transcripts in leukemogenesis remains unknown.

Resting energy expenditure and oxygen cost of breathing in patients with cystic fibrosis.

BACKGROUND: Resting energy expenditure (REE) is often increased and may contribute towards energy imbalance in patients with cystic fibrosis. Several mechanisms may lead to increased REE including the gene defect, the effect of chronic infection, and abnormal pulmonary mechanics. Increased oxygen cost of breathing (OCB) has been demonstrated in patients with chronic obstructive pulmonary disease (COPD), but has not been the subject of extensive study in cystic fibrosis. METHODS: Ten clinically stable patients with cystic fibrosis and 10 healthy control subjects were studied. OCB was estimated using the dead space hyperventilation method. Mixed expired gas fractions were measured by online gas analysers and ventilation by a pneumotachograph. After measurement of resting ventilation and gas exchange, minute ventilation (VE) was stimulated by 6-10 1/min by the addition of a dead space and OCB calculated from the slope of the differences in oxygen uptake (VO2) and VE. REE and the non-respiratory component of REE were calculated from gas exchange data. To assess the repeatability of OCB all subjects had a further study performed one week later. RESULTS: The patients had lower weight, fat free mass (FFM), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and transfer factor for carbon monoxide (TLCO) than controls. Resting respiratory rate, VE, and oxygen uptake per kilogram of FFM (VO2/kg FFM) were higher in patients (20 (7), 10.4 (1.4) 1/min and 5.5 (0.8) ml/kg FFM/min) than in controls (13 (4), 7.0 (1.2), and 4.2 (0.5), respectively.) The error standard deviation for replicated measures of OCB was 0.5 ml O2/l VE in controls and 0.8 ml O2/l VE in patients with coefficients of variation of 24% in controls and 28% in patients. The mean OCB in patients was 2.9 (1.4) ml O2/l VE and 2.1 (0.7) ml O2/l VE in controls. OCB, expressed as ml/min (VO2resp) was 28.5 (11.7) in patients and 14.0 (3.6) in controls. REE was higher in patients (125.9 (14.0)% predicted) than in controls (99.0 (9.4)%). The estimated non-respiratory component of REE was 112.1 (14.9)% for patients and 93.0 (10.0)% for controls. CONCLUSIONS: In clinically stable patients with cystic fibrosis the OCB at rest is increased but is not the sole explanation for increased metabolic rate. This contrasts with the finding in COPD where the increase in REE is largely explained by increased OCB. This study also showed poor repeatability and OCB measurements similar to earlier studies, which indicates that the technique is not suitable for longitudinal studies.

Detection of CBFB/MYH11 transcripts in patients with inversion and other abnormalities of chromosome 16 at presentation and remission.

The pericentric inversion of chromosome 16 [inv(16)(p13q22)] and t(16;16)(p13;q22) are chromosomal rearrangements frequently associated with AML FAB type M4Eo resulting in the production of a fusion gene CBFB/MYH11. We studied 17 patients with a chromosome 16 abnormality (eight M4Eo, two M1, one M2, three M4 without abnormal eosinophils, three MDS) for the presence of CBFB/MYH11 transcripts using an RT-PCR technique. 10 AML patients with inv(16) tested RT-PCR positive (eight at presentation, one in remission, one in remission and relapse). Three of these patients were originally reported by cytogenetic analysis to have del(16q22) but the positive RT-PCR results prompted a cytogenetic re-examination, resulting in the correction of the reports to inv(16). We show that although inv(16) is closely associated with AML M4Eo, it can also be detected in cases of AML M4 without abnormal eosinophils. Three cases of MDS with inv(16) were also RT-PCR positive. Four patients with other chromosome 16 abnormalities were RT-PCR negative. Four AML patients with inv(16) were studied in remission. All were RT-PCR positive, including one patient in remission for 108 months and one 22 months post allogeneic bone marrow transplant. In the latter two remission patients, RT-PCR evaluation was positive in bone marrow (BM) but not in peripheral blood, suggesting that BM may be the more informative. We conclude that this technique is valuable in the accurate molecular classification of AML, particularly as treatment options may be influenced by such information. Though RT-PCR is highly sensitive in detecting CBFB/MYH11 fusion transcripts during remission, monitoring of minimal residual disease in patients with inv(16) remains to be established.