Energy expenditure of stunted and nonstunted boys and girls living in the shantytowns of São Paulo, Brazil

BACKGROUND

Stunting increases the risk of obesity in developing countries, particularly in girls and women, but the underlying reason is not known.

OBJECTIVE

Our objective was to test the hypothesis that stunted children have lower energy expenditure than do nonstunted children, a factor that has predicted an increased risk of obesity in other high-risk populations.

DESIGN

A cross-sectional study was conducted in shantytown children from São Paulo, Brazil. Twenty-eight stunted children aged 8-11 y were compared with 30 nonstunted children with similar weight-for-height. Free-living total energy expenditure (TEE) was measured over 7 d by using the doubly labeled water method. In addition, resting energy expenditure (REE) was measured by indirect calorimetry and body composition was measured by dual-energy X-ray absorptiometry.

RESULTS

There were no significant associations between stunting and any measured energy expenditure parameter, including REE adjusted for weight (f1.gif" BORDER="0"> +/- SEM: 4575 +/- 95 compared with 4742 +/- 91 kJ/d, in stunted and nonstunted children, respectively) and TEE adjusted for weight (8424 +/- 239 compared with 8009 +/- 221 kJ/d, in stunted and nonstunted children, respectively). In multiple regression models that included fat-free mass and fat mass, girls had significantly lower TEE than did boys (P: < 0.05) but not significantly lower REE (P: = 0.17).

CONCLUSIONS

There was no association between stunting and energy expenditure after differences between groups in body size and composition were accounted for. However, the girls had lower TEE than did boys, which may help to explain the particularly high risk of obesity in stunted adolescent girls and women in urban areas of developing countries.

A new technique for the selective recording of extensor carpi radialis longus and brevis EMG

Tennis Elbow or Lateral Epicondylalgia is manifested by pain over the region of the lateral epicondyle of the humerus, related to use of the wrist extensor muscles. Extensor carpi radialis longus (ECRL) and brevis (ECRB) have been implicated in the dysfunction associated with Lateral Epicondylalgia. For muscles in the human forearm, particularly those in close proximity, selective recordings are nearly impossible without the use of fine wire, indwelling electrodes. These can be inserted in precise locations and have small recording areas. Standard electromyography texts indicate, however, that the activity of ECRL and ECRB cannot be distinguished, even with intramuscular electrodes. We present a new technique for determining the most appropriate sites at which to insert intramuscular electrodes for selective recordings of ECRB and ECRL. The location of ECRB and ECRL was measured on 10 cadaver specimens, 5 right arms and 5 left arms. The distance from the muscle origin to (1) insertion, (2) largest portion of the muscle belly, (3) most proximal fibres and (4) most distal fibres were measured and expressed relative to forearm length. The mean distance and 95% confidence interval was calculated for each of the four measures. These data indicated a significant separation of the belly of each muscle along the length of the forearm. These relative distances were used to mark electrode insertion points on three volunteers. Fine wire electrodes were used to record the electromyogram in three participants. Each participant was required to perform isometric contractions to produce (1) wrist extension torque, (2) radial deviation torque, (3) elbow flexion torque and (4) finger extension. The electromyographic recordings show clear differentiation of ECRB and ECRL with the relative activation patterns reflecting the underlying anatomical organisation of the two muscles. This technique provides an important objective method that can be used in conjunction with manual muscle testing to provide a means of ensuring accurate intramuscular electromyographic recording from these two muscles.

Evidence for a signaling system in Helicobacter pylori: detection of a luxS-encoded autoinducer

Helicobacter pylori possesses a homolog of the luxS gene, initially identified by its role in autoinducer production for the quorum-sensing system 2 in Vibrio harveyi. The genomes of several other species of bacteria, notably Escherichia coli, Salmonella enterica serovar Typhimurium, and Vibrio cholerae, also include luxS homologs. All of these bacteria have been shown to produce active autoinducers capable of stimulating the expression of the luciferase operon in V. harveyi. In this report, we demonstrate that H. pylori also synthesizes a functional autoinducer (AI-2) that can specifically activate signaling system 2 in V. harveyi. Maximal activity is produced during early log phase, and the activity is diminished when cells enter stationary phase. We show that AI-2 is not involved in modulating any of the known or putative virulence factors in H. pylori and that a luxS null mutant has a two-dimensional protein profile identical to that of its isogenic parent strain. We discuss the implications of having an AI-2-like quorum-sensing system in H. pylori and suggest possible roles that it may play in H. pylori infection.

Functional probing of the human glucocorticoid receptor steroid-interacting surface by site-directed mutagenesis. Gln-642 plays an important role in steroid recognition and binding

To elucidate which amino acids in the glucocorticoid receptor ligand-binding domain might be involved in determining steroid binding specificity by interaction with the D-ring of glucocorticoids, we have performed site-directed mutagenesis of the four amino acids Met-560, Met-639, Gln-642, and Thr-739 based on their proximity to the steroid in a model structure. Mutations of these residues affected steroid binding affinity, specificity, and/or steroid-dependent transactivation. The results indicate that these residues are located in close proximity to the ligand and appear to play a role in steroid recognition and/or transactivating sensitivity, possibly by changes in the steroid-dependent conformational change of this region, resulting in the formation of the AF-2 site. Mutation of Gln-642 resulted in a marked decrease in affinity for steroids containing a 17alpha-OH group. This effect was alleviated by the presence of a 16alpha-CH(3) group to a varying degree. Thr-739 appears to form a hydrogen bond with the 21-OH group of the steroid, as well as possibly forming hydrophobic interactions with the steroid. Met-560 and Met-639 appear to form hydrophobic interactions with the D-ring of the steroid, although the nature of these interactions cannot be characterized in more detail at this point.

Attitudes, beliefs and behaviour regarding the use of sunbeds amongst healthcare workers in Bradford

Although cosmetic tanning and unprotected solar exposure are common, little is known about general attitudes, beliefs and behaviour regarding the use of sunbeds. We sought to determine the frequency of sunbeds use in a select sample and to assess the knowledge and beliefs regarding this behaviour. A self-administered anonymous questionnaire was distributed to a sample of 648 employees work for Bradford Hospitals NHS Trust. The questionnaire explored demographic information (including hair and skin type, family history with skin cancer), frequency of sunbeds use, knowledge about the risks of UV exposure and motivations for practising this behaviour. Four hundred and eighteen women and 52 men completed the questionnaire, making a response rate of 73%. Nearly half of respondents (207; 44%) reported using sunbeds to some extent; of those 12% reported frequent use. Appearance ('to look better') was the most popular reason given by respondents for using sunbeds, followed by 'feel healthy'. Frequency of using sunbeds was found to be negatively correlated with the age of respondents and the existence of family experience with skin cancer, and strongly associated with the opinion that it is safer to use a sunbed than subathing outdoors, the female sex and smoking. It is clear from this study that the psychological factors that influence sunbeds use are complex and that so far public education campaigns have had little impact on it. This study highlights some of these psychological factors.

The development of the stria vascularis in the human foetus

The development of the stria vascularis in the human cochlea was studied in step sections of 81 human foetal temporal bones. The stria vascularis primordium can be identified as a ridge of epithelial cells on the lateral wall of the cochlear duct. The first signs of differentiation appear at the 11th week, but it is not until the 17th-18th week that the typical trilaminar structure is observed. The appearance of similar cells with notched nuclei in both marginal and mesenchymal layers at this stage suggests the possibility that some of the intermediate cells may be of epithelial origin. By the 21st week, the overall appearance resembles that of the adult structure. This occurs 1 week after the opening of the tunnel of Corti, and possibly marks the onset of cochlear function.

A phase I study of a novel potential intravaginal microbicide, PRO 2000, in healthy sexually inactive women

BACKGROUND

Although the male condom provides a reliable means of preventing HIV transmission, a broader choice of methods is required particularly in circumstances where the negotiation of condom use is difficult. Development of new products that may be effective as topical vaginal microbicides is the focus of a great deal of research activity currently. The novel agent PRO 2000, a naphthalene sulphonate derivative with in vitro activity against HIV and other sexually transmissible pathogens, is one such compound. We have studied the local and systemic safety and tolerance of a vaginal gel formulation of this agent at two concentrations (0.5% and 4%) over a 2 week period of daily exposure in two cohorts of healthy sexually abstinent women (one in London, UK, and the other in Antwerp, Belgium).

METHODS

This was a randomised, placebo controlled, double blind, three arm clinical trial conducted on two sites. Macroscopic evidence of genital epithelial changes was sought using colposcopy and evidence of microscopic inflammation was acquired using high vaginal biopsy from predetermined sites (UK cohort only). Blood levels of PRO 2000 were measured and laboratory safety tests, including coagulation screens, were performed. The impact on vaginal ecology was also assessed.

RESULTS

73 women were enrolled across both sites (36 UK, 37 Belgium); 24, 24, 25 in the 4%, 0.5%, and placebo groups respectively. Of these, 70 completed 2 weeks' exposure to the study gel. Three (all in the 4% group) withdrew owing to adverse events which were possibly or probably gel related. Cervicovaginal abrasion was seen colposcopically in three subjects after 14 days of gel use (two in the 4% group and one in the placebo group). Genital ulceration was not seen during gel use in any of the subjects who completed the study. Histological evaluation of vaginal biopsy samples (36 women only) showed evidence of increased inflammatory signs in one participant of the 4.0% group. One volunteer in the placebo group had moderate inflammation at screening and at follow up. Severe inflammation was not seen among any of the subjects tested. Plasma levels of PRO 2000 and laboratory safety tests showed no evidence of systemic absorption. No impact was seen on normal vaginal ecology in the UK cohort where samples were taken 12 hours after the last gel application.

CONCLUSION

In this phase I study PRO 2000 gel was found to be generally well tolerated with promising local and systemic safety profiles. The 0.5% gel was better tolerated than the 4% gel as fewer genital epithelial adverse events were seen in the former. Phase II studies are about to begin in sexually active women.

Induction of emetic, pyrexic, and behavioral effects of Staphylococcus aureus enterotoxin B in the ferret

Ferrets which had been orally dosed with 5 mg of Staphylococcal enterotoxin B (SEB) responded with an increase in subcutaneous temperature. At 75 min, the subcutaneous temperature was significantly higher (+ 0.9 degrees C +/- 0.38 degrees C, P < 0.007) than in control animals. Animals dosed with 1 or 2 mg of SEB responded with a small, but not significant, increase in subcutaneous temperature. All of the animals dosed with 5 mg of SEB retched and vomited. The mean latency for the onset of retching was 105 +/- 36 min, and the mean latency for the onset of vomiting was 106 +/- 34 min. The mean number of retches was 17.8 +/- 19.6, and the mean number of vomits was 2.0 +/- 1.5. These findings indicate that ferrets can be used as alternatives to primates for the study of the biological activities of SEB.

Repaired coarctation: a "cost-effective" approach to identify complications in adults

OBJECTIVES

The study was done to determine the most "cost-effective" approach to follow adults after repair of coarctation of the aorta.

BACKGROUND

Recoarctation and/or aneurysm formation following surgical repair or angioplasty for coarctation of the aorta carry a significant morbidity and mortality. Various screening tests to detect such complications are used, but little is known of their sensitivities and specificities; as a consequence, the most "cost-effective" approach to follow such patients is undefined.

METHODS

Retrospective analysis was done on the sensitivity and specificity of symptomatology, physical examination, electrocardiogram, chest radiograph, exercise testing and transthoracic echocardiography to detect recoarctation and/or aneurysm formation in 84 adult patients following surgical repair or angioplasty of coarctation of the aorta, using magnetic resonance imaging (MRI) as the gold standard test.

RESULTS

Echocardiography had the highest sensitivity in detecting recoarctation (87%) and chest radiograph the highest sensitivity in detecting aneurysm formation (67%). Combined clinical visit and echocardiography had a high sensitivity for diagnosing recoarctation and/or aneurysm formation (97%), but performing a clinical visit and an MRI on every patient without any prior screening test emerged as the most "cost-effective" strategy.

CONCLUSIONS

The most "cost-effective" approach to diagnose complications at the site of repair in patients after surgical repair or balloon angioplasty of coarctation of the aorta appears to be the combination of clinical assessment and MRI scan on every patient. If MRI resources are scant, performing a clinical assessment plus a transthoracic echocardiography and an MRI on patients with positive results is an acceptable alternative.

Genetic correction of sickle cell disease: insights using transgenic mouse models

Sickle cell disease is a hereditary disorder characterized by erythrocyte deformity due to hemoglobin polymerization. We assessed in vivo the potential curative threshold of fetal hemoglobin in the SAD transgenic mouse model of sickle cell disease using mating with mice expressing the human fetal Agamma-globin gene. With increasing levels of HbF, AgammaSAD mice showed considerable improvement in all hematologic parameters, morphopathologic features and life span/survival. We established the direct therapeutic effect of fetal hemoglobin on sickle cell disease and demonstrated correction by increasing fetal hemoglobin to about 9-16% in this mouse model. This in vivo study emphasizes the potential of the SAD mouse models for quantitative analysis of gene therapy approaches.

Two novel mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene in X-linked retinitis pigmentosa (RP3). Mutations in brief no. 172. Online

Recently a new gene called RPGR (retinitis pigmentosa GTPase regulator) was isolated in Xp21.1 and found to be mutated in patients with RP3 type X-linked retinitis pigmentosa. Two new mutations, the first a single base pair deletion and the other a two base pairs deletion, have been found in one Spanish and one Italian family.

Significant association between a silent polymorphism in the neuromedin B gene and body weight in German children and adolescents

Neuromedin B has been shown to exert an inhibiting effect on food consumption in rats. The corresponding gene NMB maps to chromosome 15q22.3-q23, a region expected to contain a gene for the Bardet-Biedl syndrome type 4 (BBS4). Based on its map position and the putative function of the encoded peptide, NMB can be considered as a candidate gene both for BBS4 and the development of human obesity. To examine its involvement in these phenotypes, we determined the genomic structure of human NMB, and performed a mutation screen in its coding region. In genomic DNA of six BBS4 patients and in a large population sample, two sequence variants were detected: a g.253C-->A transversion creating a P73T substitution and a g.401G-->A silent mutation changing the stop codon TGA into stop codon TAA. A case-control study with 92 extremely obese patients and 94 underweight students revealed a significant association between the g.401G-->A polymorphism and body weight (adjustedp = 0.03), which was confirmed in a validation sample consisting of 95 extremely obese patients, and 95 normal weight and 48 underweight individuals (Mann-Whitney p = 0.02). These results suggest a contribution of NMB or a gene in its close vicinity to genetic weight control in humans.

Early switch from intravenous to oral antibiotics and early hospital discharge: a prospective observational study of 200 consecutive patients with community-acquired pneumonia

To determine the proportion of patients who can be treated with early switch to oral antibiotics and early discharge, to evaluate clinical outcome and patient satisfaction for patients treated with early switch and early discharge, and to define the factors that interfere with early discharge for some of the patients who underwent early switch to oral antibiotic therapy.

DESIGN

Prospective study.

PARTICIPANTS

Two hundred consecutive hospitalized patients with community-acquired pneumonia.

MAIN OUTCOME MEASURES

Number of days needed to switch to oral therapy and length of hospital stay. Clinical outcome and satisfaction with care were evaluated for those patients treated with early switch and early discharge.

RESULTS

Early switch to oral antibiotics (within the first 3 days of hospitalization) was performed in 133 patients (67%). Clinical failure was documented in 1 patient. Early switch and early discharge was performed in 88 patients (44%). The mean length of hospital stay for this group was 3.4 days. The most common reason for prolonged hospitalization after the switch to oral antibiotics was the need for diagnostic workup. More than 95% of patients were satisfied with the care they had received.

CONCLUSIONS

Using simple clinical and laboratory criteria, a significant proportion of hospitalized patients with community-acquired pneumonia (44%) can be treated with early switch and early discharge. This model did not affect patient outcome, decreased the length of hospitalization, and was associated with a high level of patient satisfaction.

Rapid development of genotypic resistance to lamivudine when combined with zidovudine in pregnancy

The prevention of mother to child transmission of HIV-1 by zidovudine monotherapy is well known, but increasingly combination anti-retroviral therapy is prescribed during pregnancy. In this prospective study, 19 pregnant women with human immunodeficiency virus-1 (HIV-1) infection who elected to take anti-retroviral therapy during the second and third trimesters were treated with zidovudine or zidovudine plus lamivudine. Fourteen women treated with zidovudine monotherapy had a mean 0.3 log(10) reduction in viral load and a mean 52 x 10(6)/L (17%) increase in CD4+ lymphocytes at delivery compared with pre-treatment samples. Genotypic mutations associated with decreased susceptibility to zidovudine were detected in 2 of 10 women at delivery. Five women with more advanced HIV-1 infection were treated with zidovudine plus lamivudine and a mean 1.5 log(10) reduction in viral load together with a mean 30 x 10(6)/L (33%) increase in CD4+ lymphocytes was observed in this group. However, four of five women in the dual therapy arm had the M184V mutation in the reverse transcriptase gene associated with decreased susceptibility to lamivudine at delivery. We conclude that zidovudine plus lamivudine reduced HIV-1 plasma viraemia to low levels in pregnant women with advanced HIV-1 disease but the rapid development of genotypic resistance to lamivudine indicates that additional therapy is required both for the long-term benefit of the mothers and to prevent the development of resistant virus that may be transmitted to the infant.

Recent concepts in the neurophysiology of pain

This paper describes many of the processes that exist for upregulation of the nociceptive system in response to tissue injury. The processes of peripheral and central sensitization are described. Potential interactions between the nociceptive, motor and autonomic systems are considered. The potential for psychosocial factors to influence neuroplasticity within the nociceptive system is also discussed.

Human and mouse ISLR (immunoglobulin superfamily containing leucine-rich repeat) genes: genomic structure and tissue expression

We have previously reported a transcript of the novel gene for human immunoglobulin superfamily containing leucine-rich repeat (ISLR). By additional screening of a human retina cDNA library, we isolated another type of transcript with a 5' UTR different from that of the previously reported type. Genomic sequencing of the ISLR gene revealed that these two types of transcripts, ISLR-1 and ISLR-2, originated from the same gene but are composed of different first exons. Because the entire open reading frame is contained in the second exon, these two transcripts produce the same protein. Radiation hybrid mapping linked the ISLR gene to AFM248yh1, which is in the critical region of Bardet-Biedl syndrome type 4 (BBS4) on chromosome 15. Sequence analysis of the ISLR gene in five BBS4 patients, however, showed no mutations, although a few polymorphic changes were detected. Cloning of the mouse homolog of ISLR (Islr) revealed that the predicted protein consists of 428 amino acids, 86% of which are identical to those of ISLR. The Islr gene was expressed in various mouse tissues, including retina, in which Islr mRNA was detected in the ganglion cell layer, the inner nuclear layer, and the inner segment of the photoreceptor.

The displacement, velocity and frequency profile of the frontal plane motion produced by the cervical lateral glide treatment technique

OBJECTIVE

To investigate the specificity of linear and angular displacement, peak velocity and frequency of oscillation of the frontal plane motion produced by the lateral glide treatment technique of the cervical spine.

DESIGN

A within-subjects design was used.

BACKGROUND

The lateral glide treatment technique of the cervical spine has previously been shown to produce specific neurophysiological effects, whereas the technique's biomechanical effects remain uninvestigated. A relationship may exist between a technique's biomechanical effects and its clinical outcome.

METHODS

Eight asymptomatic subjects participated in the study. Retroreflective markers were placed dorsally at the occiput, and the C5, T1, T3 and T5 vertebrae. Movement of these markers was recorded by a video processor. The same physiotherapist applied the treatment technique to each subject.

RESULTS

Linear displacement (3.336 cm) and peak velocity (13.643 cm/s) between C5 and T1 markers was greater than between T1 and T3, Occiput and C5, and T3 and T5. Angular displacement about C5 (26.5 degrees ) was twice that about T1 and T3, but unlike T1 and T3 occurred in the opposite direction to that of the treatment technique. Frequency of oscillation was 1. 255 Hz.

CONCLUSION

The lateral glide treatment technique produced a characteristic ipsilateral displacement rather than side flexion, predominantly at its region of application.

RELEVANCE

This study provides the basis for further investigations of the mechanisms of action of the lateral glide treatment technique. It also provides clinicians with guidelines for the application of this technique.

Difference between RP2 and RP3 phenotypes in X linked retinitis pigmentosa

AIM

X linked retinitis pigmentosa (XLRP) has two genetic loci known as "RP2" and "RP3". Clinical features reported to differentiate RP2 from RP3 include a higher prevalence of myopia and primary cone dysfunction in RP2, and late onset night blindness and tapetal reflex in RP3. Members from 14 XLRP families were examined in an attempt to verify these differences.

METHODS

16 affected males and 37 females from 14 XLRP families assigned as either RP2 or RP3 by haplotype analysis and/or by heterogeneity analysis were examined. Members of all 14 families who were willing to participate but unavailable for examination were contacted and detailed interviews carried out.

RESULTS

No clear phenotypic differences were found that could be used to reliably differentiate RP2 from RP3 with respect to myopia and onset of night blindness. The tapetal reflex was also found to be present in carriers of both RP2 and RP3.

CONCLUSIONS

XLRP is a heterogeneous class of rod degenerative disorders with no clear phenotypic differentiation between the two genetic loci RP2 and RP3. There is a continuum of clinical presentations which can be seen in both RP2 and RP3, but the features within a given family tend to be consistent. However, interfamilial variability is prevalent leading to a wide range of clinical presentations and more than one abnormal allele at each gene locus cannot be excluded.

Drug monitoring of antiretroviral therapy for HIV-1 infection: method validation and results of a pilot study

BACKGROUND

Antiretroviral therapy for HIV-1 infection has become increasingly complex. The availability of new and potent drugs and progress in understanding the pathogenesis of HIV-1 infection have led to the establishment of new treatment paradigms. The varying dosing regimens, associated toxicities, and the potential for drug-drug and food-drug interactions further complicate treatment. This complexity contributes to patient nonadherence. Because clinicians have no tools to monitor adherence or drug-drug interactions and because response requires that therapy exceed the known inhibiting concentration, serum monitoring of antiretroviral therapy may play a role in improving treatment of HIV-1 infection. We report methods to quantify serum concentrations of antiretroviral drugs used to treat HIV-1 infection, precision and interference studies of these methods, and results observed in a pilot evaluation of blood serum concentrations from 12 human subjects.

METHODS

HPLC offers adequate sensitivity to measure peak or trough serum concentrations of delavirdine, lamivudine, nevirapine, indinavir, nelfinavir, ritonavir, and saquinavir and peak serum concentrations of stavudine, zidovudine, and didanosine with reasonable precision.

RESULTS

Peak indinavir serum concentrations in most patients were in the range of 1-10 mg/L, and trough concentrations were in the range of 0.1-0.5 mg/L. Peak stavudine concentrations were in the range of 0.3-1.3 mg/L, and trough concentrations were in the range of 0.1-0.5 mg/L. Peak zidovudine concentrations were in the range of 0.1-1.1 mg/L.

CONCLUSIONS

Because this was a blood serum concentration-seeking pilot study to evaluate analytic performance, we do not report on the correlation of drug response to blood concentration. However, the concentrations observed in patients are generally consistent with blood concentrations reported from studies of monotherapy.

Laparoscopy with laparoscopic ultrasonography in the TNM staging of pancreatic carcinoma

A prospective study was performed comparing laparoscopy with laparoscopic ultrasonography (LapUS), transabdominal ultrasonography (USS), computed tomography (CT), and selective visceral angiography with portal phase venography (SVA) for the assessment of resectability in 50 patients with pancreatic or periampullary cancer. The results were stratified by TNM stages. Tumor unresectability was demonstrated in 36 patients (72%). The sensitivity of LapUS for demonstrating the index lesion was 96%. Laparoscopic ultrasonography failed to predict factors precluding resection by T stage in six patients, and there were no significant differences in the ability of any modality to predict local resectability (predictive value 58-73%). Laparoscopic ultrasonography did not overestimate T stage and was significantly more specific for assessing unresectability compared with USS (100% vs. 64%, p<0.05) and CT (100% vs. 47%, p<0.005). No imaging investigation was able to assess the N stage accurately. Metastases were confirmed in 16 patients (32%), with LapUS proving significantly more sensitive than USS (94% vs. 29%, p<0.001) and CT (94% vs. 33%, p<0.005). The addition of LapUS to the laparoscopic examination did not change the M stage in any patient, as all metastases were superficially located. Laparoscopy with LapUS was the most reliable method for assessing overall tumour resectability and was significantly more predictive than CT (97% vs. 79%, p<0.005). These results confirm that laparoscopy is indispensable for detecting occult intraabdominal metastases. LapUS reliably predicts tumor unresectability, offsetting the tendency of USS and CT to overestimate T stage. Methods of accurate N staging remain elusive, and the use of routine SVA is not justified.

Adding Alzheimer's. The industry targets a growing market

The gaga, go-go early boom may be over for assisted living, but life most definitely goes on for owners and operators. True, money isn't as easy to come by as it once was, as Wall Street analysts and financiers worry about overbuilding and the quality of earnings. The competition is getting more intense and savvier daily. Fill-up time has lengthened, especially in secondary markets where barriers to entry are low. Most of the affluent suburbs that showed up in everybody's initial feasibility studies are now saturated with high-end assisted living facilities. And the capital crunch has turned many cash-strapped developers into eager sellers. But consumer demand keeps growing, and the demographics look even brighter 10 or 20 years down the line. The trick is to find new ways to distinguish yourself from your competition--and, perhaps, to attract financing. In this year's special section, we suggest several ways of accomplishing both of those goals.

The use of infrared spectrophotometry for measuring body water spaces

BACKGROUND

The conventional method of measuring total body water by the deuterium isotope dilution method uses gas isotope ratio mass spectrometry (IRMS), which is both expensive and time-consuming. We investigated an alternative method, using Fourier transform infrared spectrophotometry (FTIR), which uses less expensive instrumentation and requires little sample preparation.

METHOD

Total body water measurements in human subjects were made by obtaining plasma, saliva, and urine samples before and after oral dosing with 1.5 mol of deuterium oxide. The enrichments of the body fluids were determined from the FTIR spectra in the range 1800-2800 cm-1, using a novel algorithm for estimation of instrumental response, and by IRMS for comparison.

RESULTS

The CV (n = 5) for repeat determinations of deuterium oxide in biological fluids and calibrator solutions (400-1000 micromol/mol) was found to be in the range 0.1-0.9%. The use of the novel algorithm instead of the integration routines supplied with the instrument gave at least a threefold increase in precision, and there was no significant difference between the results obtained with FTIR and those obtained with IRMS.

CONCLUSION

This improved infrared method for measuring deuterium enrichment in plasma and saliva requires no sample preparation, is rapid, and has potential value to the clinician.