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.

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.

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.

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.

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.

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 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.

Persistence of RAR alpha-PML fusion mRNA detected by reverse transcriptase polymerase chain reaction in patients in long-term remission of acute promyelocytic leukaemia

Acute promyelocytic leukaemia (APL) is characterized by t(15;17), which results in the formation of two chimaeric genes, PML-RAR alpha and RAR alpha-PML. PML-RAR alpha transcripts have been detected in all cases of APL whilst those of RAR alpha-PML have been detected in only about 67% of cases. We have used reverse transcriptase polymerase chain reaction (RT-PCR) to detect both fusion transcripts serially in 18 patients in remission of APL after chemotherapy and bone marrow transplantation. All patients were negative for PML-RAR alpha, whereas in six patients (remission 3-9 years) RAR alpha-PML was consistently detected. Only one patient at remission showed the 5' breakpoint RAR alpha-PML, with the rest showing the 3' breakpoint 144 bp RAR alpha-PML. The level of sensitivity for detecting RAR alpha-PML was some 10-fold higher than that for PML-RAR alpha. Serial negative tests for PML-RAR alpha have been correlated with durable remissions, suggesting possible eradication of residual leukaemia in APL. Our results, however, show persistence of t(15;17) cells expressing RAR alpha-PML fusion mRNA in patients in long-term remission of APL. They indicate that patients considered clinically 'cured' of APL still have molecular evidence of minimal residual disease and also provide further insight into the biology of acute myeloid leukaemia.

Clonality studies in patients undergoing allogeneic and autologous bone marrow transplantation for haematological malignancies

Twenty three allogeneic bone marrow transplant (BMT) patients with female donors and 23 female autologous transplant patients were assessed for clonality status after transplant to determine the nature of haemopoietic reconstitution. The X chromosome probes PGK, HPRT and M27 beta were used to assess clonality by analysis of X chromosome inactivation. Results were obtained for 15 allogeneic patients, 14 of whom gave polyclonal results after transplantation. One patient gave a skewed pattern of X chromosome inactivation after transplant due to extreme Lyonisation of the donor cells. Results were obtained from 19 autologous transplant patients, 17 of whom gave polyclonal results after transplant. Two patients gave patterns of skewed X chromosome inactivation in post-transplant samples, reflected in their constitutive DNA, due to extreme Lyonisation. The remaining patients could not be assessed because of hypermethylation of HpaII sites or indistinguishable digested and undigested alleles using M27 beta probe analysis. Haemopoietic reconstitution after allogeneic and autologous BMT, in our patients, was found to be polyclonal. Skewed patterns of X chromosome inactivation seen after transplant were due to extreme Lyonisation of the infused haemopoietic cells.

Incorporating the nutrition screening initiative into the dental practice

Older patients' nutritional status must be assessed for their morbidity and mortality to be decreased and their quality of life improved. Food and fluid intake is markedly influenced by oral health status. In turn, oral health has an interrelationship with general health. Because nutritional status and oral health exist in a symbiotic relationship, it is essential that the dental team identify older patients who are nutritionally at risk. Screening for nutritional problems in elderly dental patients is made easier with screening instruments developed by the Nutrition Screening Initiative (NSI). The NSI developed criteria to determine risk factors for poor nutritional status in older Americans. The DETERMINE Your Nutritional Health checklist, a 10-item screening instrument, followed by the Levels I and II Nutrition Screens, can be used in the dental office to ascertain which elderly patients are most likely to be in danger of experiencing nutritional problems. The dental team can then perform interventions and/or make appropriate referrals.

Detection of t(8;21) by reverse transcriptase polymerase chain reaction in patients in remission of acute myeloid leukaemia type M2 after chemotherapy or bone marrow transplantation

Seven patients with acute myeloid leukaemia (AML) type M2 and t(8;21), treated with intensive chemotherapy followed in two cases by allogeneic or autologous bone marrow transplant (BMT), were tested for the presence of transcripts of the characteristic chimaeric gene AML1/ETO by reverse transcriptase polymerase chain reaction (RT-PCR) at serial intervals during remission. Six patients, including both BMT patients, demonstrated persistence of t(8;21), one being consistently negative in peripheral blood but bone marrow positive. Bone marrow may, therefore, be more reliable than peripheral blood for detecting residual t(8;21) cells. Our results show persistence of t(8;21) cells in AML-M2 patients following chemotherapy or BMT, some of whom were in long-term remission.

Utilizing a 24-hour dietary recall and culturally specific diabetes education in Mexican Americans with diabetes

Two objectives were established for this study: 1) to assess the impact of a culturally specific, intensive diabetes education program on dietary patterns, and 2) to assess nutrient consumption relative to the Recommended Dietary Allowances. The study population consisted of elderly Mexican Americans with diabetes living in Harlingen and Brownsville, Texas. The experimental group (n = 78) participated in an intense, 2-hour nutrition education session, while the control group (n = 74) did not. The education session was conducted for groups of eight subjects via videotapes and interactive discussion. All groups experienced significant weight loss except the women in the experimental group. After the education program, however, the experimental women had increased the percentage of calories consumed daily from carbohydrate. Mean calcium consumption was substantially less than the RDA in all groups, and inadequate amounts of ascorbic acid and vitamin A often were consumed. Intensive, frequent, long-term follow-up appears essential for more sustained results.

Clonal remissions in acute myeloid leukaemia are commonly associated with features of trilineage myelodysplasia during remission

Clonal haemopoiesis has previously been demonstrated in some 30% of patients in remission of acute myeloid leukaemia (AML). Whilst a 'clonal remission' in many such patients may represent a skewed X-chromosome inactivation pattern in haemopoietic cells, its relationship to an underlying preleukaemic state remains uncertain. We therefore analysed the clonal status of 48 female patients in remission of AML using X-chromosome linked restriction fragment length polymorphisms (RFLPs) within the X-linked PGK and HPRT genes and the DXS255 (M27 beta) locus, and carried out in conjunction a detailed study of the morphological and karyotypic features of the patients' bone marrows. During remission, 35 patients (73%) with AML demonstrated nonclonal haemopoiesis, and their bone marrows were morphologically normal. Remission haemopoietic tissue in nine cases (19%) showed a skewed X-chromosome inactivation pattern and remission bone marrows in these patients had features of trilineage myelodysplasia (TMDS), with seven having similar features at presentation. Analysis of constitutional DNA showed a non-clonal pattern in seven of these patients, but was unsuccessful in two cases. These nine patients with post-chemotherapy TMDS were considered to have true clonal haemopoiesis. Four patients (8%) with a skewed X-chromosome inactivation pattern had normal remission bone marrows. Analysis of constitutional DNA showed a skewed pattern in two of these patients, but was unsuccessful in two cases. Cytogenetic investigation during remission in the nine patients with TMDS showed a normal karyotype in four cases and the acquisition of new karyotypic abnormalities in three cases. In contrast, 10 female patients in remission of de novo acute lymphoblastic leukaemia (ALL) were shown to have non-clonal haemopoiesis. We conclude that the majority of patients with AML who achieve remission after cytoreductive chemotherapy have non-clonal haemopoiesis, and when clonal remissions are observed these are commonly associated with the development of trilineage myelodysplasia in the bone marrow, with or without karyotypic abnormalities. True clonal remission in association with morphologically normal haemopoiesis is a rare entity, the significance and frequency of which remain uncertain.

Relapsed myelodysplastic clone differs from acute onset clone as shown by X-linked DNA polymorphism patterns in a patient with acute myeloid leukemia

We have used a recombinant strategy based on X-chromosome-linked restriction fragment length polymorphisms to analyze clonality in a female patient with acute myeloid leukemia (AML). She presented with features compatible with a diagnosis of refractory anemia with excess of blasts in transformation, but soon progressed into overt AML. Intensive chemotherapy successfully induced a complete remission, but she later relapsed into a second myelodysplastic phase. Although analysis at presentation and relapse showed that hematopoiesis was clonal at both phases of the patient's disease, the genotype of the two clones was different. We believe the unexpected finding of a switch in clonality shows new insights into the biology and origin of AML.

Polymerase chain reaction analysis of allele frequency and loss at the Harvey ras locus in myeloid malignancies

The hypothesis that 'rare' variable number tandem repeat (VNTR) alleles of the Harvey ras (Ha-ras) locus are an inherited predisposing factor in myeloid malignancies has been evaluated. We describe an application of the polymerase chain reaction (PCR) which amplifies the VNTR region at the Ha-ras locus and offers a number of advantages over conventional Southern analysis. Ha-ras VNTR genotypes were assigned to 57 normal subjects, 46 patients with acute myeloid leukaemia (AML), 26 with myelodysplastic syndrome (MDS) and 49 with chronic granulocytic leukaemia (CGL). By comparison with previous reports we found significantly higher frequencies of rare alleles (20.2%) in our normal subjects of whom more than 35% had at least one 'rare' allele. The frequencies of rare alleles in the patient groups was not significantly different from the normal group (chi 2 = 0.54, p = 0.91). In studies of constitutional and leukaemic DNA from patients with AML, we found that allelic loss at the Ha-ras locus was not a common phenomenon. The improved resolution achievable with PCR compared with Southern analysis was demonstrated by the inability of Southern analysis to resolve six out of 34 PCR heterozygotes. We therefore suggest that previous studies showing linkage between rare Ha-ras alleles and susceptibility to malignancy should be reevaluated using our sensitive PCR technique.

Purification and immunological detection of pea nuclear intermediate filaments: evidence for plant nuclear lamins

A major structural component of the inner face of the nuclear envelope in vertebrates and invertebrates is the nuclear lamina, an array of 1–3 extrinsic membrane proteins, lamins A, B and C. These proteins are highly homologous to intermediate filaments and are classified as type V. We report the first purification, antigenic characterization and immunocytochemical localization of putative plant lamin proteins from pea nuclei. We conclude that plant cells contain this ancestral class of intermediate filaments in their nuclei and that regulation of nuclear envelope assembly/disassembly and mitosis in plants may be similar to that in animal cells.

An electrophysiological and spectroscopic study of the properties and structure of biological calcium channels. Investigations of a model ion channel

The N- and C-terminally protected peptide N-acetyl-Asp-Phe-Ala-Asn-Arg-Val-Leu-Leu-Ser-Leu-Phe-Thr-Ile-Glu-Met-Leu -Leu-Lys-Met-Leu-NH2, closely based on the sequence of the putative S2 membrane spanning helix of domain II of the dihydropyridine receptor calcium channel of the T-system of skeletal muscle, residues 465-486 (Tanabe et al. (1987) Nature 328, 313-318) has been synthesised. Conductance measurements in planar lipid bilayers show that the peptide is capable of inducing the transmembrane passage of calcium and barium ions, in preference to monovalent cations. No anion conductance is observed. 1H-NMR spectroscopy demonstrates that in an amphilic solvent, methanol, the peptide forms highly stable structures characterised by very slow exchange with solvent of peptide N-H protons. Double-quantum filtered phase-sensitive COSY shows that, on the basis of NH-CH alpha scalar coupling constants, most peptide torsion angles are appropriate to an overall alpha-helical conformation; the presence of some alpha-helix is also supported by CD measurements. Most side-chain connectivities have been identified in a DIPSI-TOCSY experiment. This evidence has been used to construct a low-resolution model of the ion-conducting channel of the muscle T-system dihydropyridine receptor from the sequences of the four homologous putative channel-lining stretches. It is characterised by an association of acidic residues at the putative extra-membranous face of the channel, followed by a predominantly hydrophobic band. The next prominent feature of the model is an ordered array of four acidic residues (glutamates 100, 478, 846 and 1164), followed by four lysines (104, 482, 850 and 1168) which may play a gating role.

Cytokinin increases intracellular Ca2+ in Funaria: detection with Indo-1

Changes in intracellular [Ca2+] ([Ca2+]i) after cytokinin-treatment in protonema cells of the moss Funaria hygrometrica have been measured using the pentapotassium salt of Indo-1. The extent of dye loading strongly depended on lowering the pH of the incubation medium to 5.0. Exposing dye-loaded cells briefly with Mn2+ did not quench fluorescence suggesting that the source of fluorescence is from the cytoplasm and not from the cell wall. Indo-1 remains responsive to changes in [Ca2+]i in Funaria cells. The [Ca2+]i in quiescent cells (with and without extracellular Ca2+) is 250 nM, which is within the range of reported [Ca2+]i of other plant cells. Treatment of cells with extracellular cytokinin in 4 mM Ca2+ induced a three-fold increase in [Ca2+]i to 750 nM in target caulonema cells. This increase was not observed in Ca(2+)-free medium. These target cells respond to cytokinin treatment by an asymmetrical division, while non-target chloronema cells do not divide. Cytokinin appears to increase [Ca2+]i by extracellular Ca2+ uptake. However, non-target chloronema cells and tip cells also respond to cytokinin treatment by increasing [Ca2+]i. The differential physiological response of these cell types to hormonal stimulation must lie further down the signal transduction chain.

Nucleosome depletion alters the chromatin structure of Saccharomyces cerevisiae centromeres

Saccharomyces cerevisiae centromeric DNA is packaged into a highly nuclease-resistant chromatin core of approximately 200 base pairs of DNA. The structure of the centromere in chromosome III is somewhat larger than a 160-base-pair nucleosomal core and encompasses the conserved centromere DNA elements (CDE I, II, and III). Extensive mutational analysis has revealed the sequence requirements for centromere function. Mutations affecting the segregation properties of centromeres also exhibit altered chromatin structures in vivo. Thus the structure, as delineated by nuclease digestion, correlated with functional centromeres. We have determined the contribution of histone proteins to this unique structural organization. Nucleosome depletion by repression of either histone H2B or H4 rendered the cell incapable of chromosome segregation. Histone repression resulted in increased nuclease sensitivity of centromere DNA, with up to 40% of CEN3 DNA molecules becoming accessible to nucleolytic attack. Nucleosome depletion also resulted in an alteration in the distribution of nuclease cutting sites in the DNA surrounding CEN3. These data provide the first indication that authentic nucleosomal subunits flank the centromere and suggest that nucleosomes may be the central core of the centromere itself.

Long-term cardiorespiratory effects of amelioration of renal anaemia by erythropoietin

The long-term cardiorespiratory effects of recombinant human erythropoietin treatment were investigated in ten haemodialysis patients by means of maximum exercise testing, lung function tests, echocardiography, chest X-ray, and rheological assessment over 12 months. There were significant rises in exercise time (mean [SD] 13.2 [5.5] to 20.0 [6.2] min), maximum oxygen consumption (19.1 [7.0] to 25.0 [6.7] ml.min-1.kg-1), and anaerobic threshold (11.7 [3.6] to 15.4 [4.8] ml.min-1.kg-1) after 2 months of erythropoietin treatment. The improvements were maintained but not augmented on repeat testing after 4, 8, and 12 months of therapy. Carbon monoxide transfer [corrected] rose from 15.5 (2.9) to 18.6 (3.7) ml.min-1.mm Hg-1. There was a substantial reduction in exercise-induced cardiac ischaemia (eight patients had significant ST segment depression before erythropoietin, only one after 2 months' treatment, and none after 12 months' treatment), despite a significant rise in whole blood viscosity. Left ventricular mass, as estimated by echocardiography, progressively decreased from 354 (169) g to 251 (95) g after 12 months' treatment, and four patients showed a reduction in cardiothoracic ratio on chest X-ray.

Simple method for granulocyte-macrophage cell culture and staining in soft agar: comparison with a standard research technique

A modified, small volume, two phase, disc culture system for CFU-GM (seven and 14 days of incubation) was compared with a standard single layer system. The 1 ml single layer cultures were counted unstained in situ before both sets of cultures were transferred to glass slides for staining. Bone marrows were cultured from forty eight subjects, including normal controls and patients with acute non-lymphoblastic leukaemia, acute lymphoblastic leukaemia, and myelodysplastic syndrome. Observer error was least with the disc cultures, whereas variation between replicate cultures was similar for both methods. A high degree of correlation was found between the two methods for both day 7 (r = 0.90) and day 14 (r = 0.91) cultures. The number of colonies and clusters was higher with the disc system, indicating better cloning efficiency. Analysis of subsets of clinical groups showed similar patterns of abnormality with both systems. The simplicity of the method makes the use of this technology possible in most laboratories, and the superior morphological resolution may increase the clinical usefulness of such studies.

The need for geriatric dental education

The poor oral health status of the elderly and the structural and attitudinal barriers that prevent dental care utilization by them, present a serious challenge for the elderly as well as for the dental profession. This challenge becomes even greater when the importance of good oral health status to the quality of life is considered. The aged person's feeling of individual well-being and favorable self-image, ability to communicate and socialize, ability to maintain adequate nutrition, and to taste and enjoy foods can be dependent upon good oral health status and hygiene. Older patients benefit physically and psychologically from more efficient dental treatment and more compassionate care given by people who understand the problems they face. In short, a better understanding of the principles of geriatric care by health professionals and staff will save both public money and private anguish. Tomorrow's elderly are expected to demand more attention and intervention to meet their changing needs. There is no reason to believe that the extension of education and training cannot begin to achieve this goal.

Respiratory disability in ex-cotton workers

A high proportion of textile workers handling cotton and flax complain of respiratory symptoms and show a loss in lung function. These effects are reversible in the early stages but the degree to which they lead to permanent respiratory disability is unknown. Two surveys were therefore conducted in which respiratory function and symptoms were compared in ex-textile workers and in control subjects who had never been exposed to textile dusts. One survey was of ex-flax workers in Northern Ireland. The present survey was of ex-cotton workers in Lancashire. A survey of random population samples in Oldham and Bolton, in both of which cotton had formerly been the most important source of employment, was conducted. After allowing for age, height, and smoking, lung function was about 2-8% lower in the ex-textile workers than in controls who had never been exposed to any dust. Ex-textile workers were slightly shorter than the controls, suggestive of past social and nutritional deprivation which may have contributed to the decrement in lung function. There was evidence of a small but increasing decrement in lung function with an increase in a "dust exposure" score. For men, about 15 years of heavy dust exposure was associated with a loss in FEV1 equivalent to that shown by light or ex-smokers. For women, 15 years of heavy dust exposure appeared to be associated with a decrement in FEV1 about half that of light smoking.

Cytokinin activation and redistribution of plasma-membrane ion channels in Funaria : A vibrating-microelectrode and cytoskeleton-inhibitor study

I have investigated changes in electrical current across the plasma membrane that occur during cytokinin-induced bud formation in Funaria hygrometrica Hedw., using a non-intrusive vibrating microelectrode. Before cytokinin treatment the target caulonema cells have maximal inward current at the nuclear region. After cytokinin treatment inward current increases twofold along the length of the cell. Within minutes, however, current decreases at both the nuclear zone and the proximal end while increasing at the distal end of target cells, preceding and predicting the presumptive division site. Inward current at the distal end falls to resting levels after establishment of a bulging growth zone, and remains low around developing buds. This current is blocked by gadolinium nitrate, a Ca(2+)-uptake inhibitor, indicating a Ca(2+) component of the current. The polarity of the target cells can be disrupted by microfilament inhibitors and cytokinin-induced buds form over the nucleus, halfway along the length of the cell. I suggest that cytokinin activates plasma-membrane ion channels which are subsequently redistributed to the distal ends of target cells by a microfilament-dependent process. Cytokinin-induced concentration of ion channels over presumptive bud sites may be envisioned to exert spatial control of cytoplasmic ion concentrations and stimulate bud formation by establishing a new growth zone, directing nuclear migration, and stimulating cell division.

Immunofluorescence visualization of phytochrome in Pisum sativum L. epicotyls using monoclonal antibodies

We have investigated the cellular distribution of phytochrome in epicotyls of dark-grown pea (Pisum sativum L.) seedlings using monoclonal antibodies to pea phytochrome. Screening of the eight available antibodies both by an enzymelinked immunosorbent assay (ELISA) and by their ability to visualize phytochrome in situ by immunocytochemical fluorescence demonstrated that: (1) three antibodies work well for immunofluorescence; (2) none of the eight antibodies discriminates between the red- and the far-red-absorbing forms of phytochrome (Pr, Pfr) as assayed by ELISA; (3) the antigenicity of phytochrome is reduced by fixation with formaldehyde with respect to all eight antibodies; and (4) two antibodies that bind well to formaldehyde-fixed phytochrome as assayed by ELISA do not bind well to phytochrome in situ. Phytochrome is observed in both cortical and stomatal guard cells of the epicotyl and exhibits a homogeneous cytoplasmic distribution in non-irradiated tissue. After red-light (R) treatment phytochrome becomes transiently inaccessible to antibodies. If maintained in the Pfr form for 10 min at room temperature before fixation, at least a portion of the phytochrome pool becomes accessible to antibodies and assumes a "sequestered" distribution. Both of these effects are almost entirely either prevented or reversed by subsequent far-red light treatment. We believe that the transient inaccessibility of phytochrome to antibodies after R irradiation is not a function of its conformational state. We suggest instead that R treatment rapidly induces an association of phytochrome with a subcellular component that interferes with antibody binding and that the "sequestered" areas represent a phytochrome pool that is distinct from both the diffusely distributed phytochrome in non-irradiated cells and from that phytochrome which is inaccessible to antibodies immediately after R irradiation.

Allergy to inhaled egg material

The use of a spray system to coat meat rolls with egg solution resulted in the development of asthmatic type symptoms in eight of thirteen workers exposed to the spray. Symptoms were severe in five workers, less severe in two, and one worker experienced vague symptoms. Even though precipitins were present in nine of the workers there were no pyrexial episodes nor influenza-like symptoms occurring some hours after inhaling the egg material to suggest extrinsic allergic alveolitis. All sera with precipitins reacted against an antigen in egg yolk, two sera only to this antigen but no precipitins to ovalbumin were detected. Lung function, X-ray and haematology provided no evidence that the inhalation of egg had lasting detrimental effects. There was no correlation between clinical response, skin testing, IgE levels and precipitins, hence, for each individual none of these parameters is predictive. However, collectively the results show sensitization and this has been confirmed by lack of symptoms when a different method of coating the pastry was adopted.