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.

Total serum IgE and its association with asthma symptoms and allergic sensitization among children

BACKGROUND

Asthma and wheezing during childhood are associated with elevated total serum IgE and with allergic sensitization to local aeroallergens. However, little is known about the longitudinal relationship between total serum IgE and the development of wheezing and allergic sensitization during childhood.

OBJECTIVE

The purpose of our investigation was to determine the relationship between total serum IgE and the development of wheezing and allergic sensitization in childhood.

METHODS

Our study subjects were participants in the Tucson Children's Respiratory Study who underwent an IgE measurement in at least 1 of 3 surveys (at years 1, 6, and 11) and complete allergy skin tests during the latter 2 surveys. The children's phenotypes were categorized on the basis of skin test response (never, early, and late) and wheezing status (never, early, late, and persistent). Repeated-measures analyses were used, allowing subjects to be included who had unequal numbers of IgE observations (a total of 263 boys and 277 girls).

RESULTS

We found that total serum IgE levels track with age: subjects with high serum IgE levels less than 1 year old continued to have high IgE levels at ages 6 and 11 years. Both persistent wheezing and early sensitization were associated with high serum IgE levels at all ages. Boys who had late or persistent wheezing or who were sensitized early or late had high serum IgE levels as early as age 9 months, whereas only girls with persistent wheezing and early sensitization had elevated IgE levels at that age. Children who wheezed only in the first years of life and not after (ie, those with early wheezing) had serum IgE levels that were not different from those of nonwheezing children.

CONCLUSION

On the basis of these findings we conclude that although total serum IgE tracks with age, children who are predisposed to persistent wheezing and early sensitization to local aeroallergens already have high levels of IgE at age 9 months. This suggests that the predisposition to respond to environmental stimuli through high levels of IgE precede early allergic sensitization, indicating that there may be a common defect in the development of the immune system involving IgE production and early allergic sensitization.

Evidence of avian leukosis virus subgroup E and endogenous avian virus in measles and mumps vaccines derived from chicken cells: investigation of transmission to vaccine recipients

Reverse transcriptase (RT) activity has been detected recently in all chicken cell-derived measles and mumps vaccines. A study of a vaccine manufactured in Europe indicated that the RT is associated with particles containing endogenous avian retrovirus (EAV-0) RNA and originates from the chicken embryonic fibroblasts (CEF) used as a substrate for propagation of the vaccine. We investigated the origin of RT in measles and mumps vaccines from a U.S. manufacturer and confirm the presence of RT and EAV RNA. Additionally, we provide new evidence for the presence of avian leukosis virus (ALV) in both CEF supernatants and vaccines. ALV pol sequences were first identified in particle-associated RNA by amplification with degenerate retroviral pol primers. ALV RNA sequences from both the gag and env regions were also detected. Analysis of hypervariable region 2 of env revealed a subgroup E sequence, an endogenous-type ALV. Both CEF- and vaccine-derived RT activity could be blocked by antibodies to ALV RT. Release of ALV-like virus particles from uninoculated CEF was also documented by electron microscopy. Nonetheless, infectivity studies on susceptible 15B1 chicken cells gave no evidence of infectious ALV, which is consistent with the phenotypes of the ev loci identified in the CEF. PCR analysis of ALV and EAV proviral sequences in peripheral blood mononuclear cells from 33 children after measles and mumps vaccination yielded negative results. Our data indicate that the sources of RT activity in all RT-positive measles and mumps vaccines may not be similar and depend on the particular endogenous retroviral loci present in the chicken cell substrate used. The present data do not support transmission of either ALV or EAV to recipients of the U.S.-made vaccine and provide reassurance for current immunization policies.

Preclinical and clinical studies of MMP inhibitors in cancer

The role of matrix metalloproteinases in tumor angiogenesis and growth is now well recognized for models of both human and animal cancer. Clinical studies currently under way with the prototype matrix metalloproteinase inhibitor, marimastat, will establish whether inhibitors of these enzymes are of benefit in the treatment of different types of human cancer. On chronic therapy in humans, marimastat induces a reversible tendinitis that can also be detected in certain animal species. This paper compares the ability of broad-spectrum and various types of selective matrix metalloproteinase inhibitors to induce tendinitis and to exhibit anticancer effects in an animal cancer model. Under conditions in which both systemic exposure and inhibitor potency are controlled, selective inhibitors are less pro-tendinitic, but are weaker anticancer agents than broad-spectrum agents such as marimastat. The clinical relevance of these findings is discussed.

Acute in vivo neurotoxicity of peptides from Maedi Visna virus transactivating protein Tat

Lentiviruses such as Maedi Visna virus (MVV) in sheep, and human immunodeficiency virus (HIV) in man often cause a variety of neurological syndromes in later stages of infection. Neuropathological investigations reveal damage to myelin and astrocytosis in both white and grey matter. MVV infection induces axonal damage with some areas of necrosis while neuronal loss, and synaptic damage have been reported in HIV-1 infection. It is not clear, at present, how this neurodegeneration is mediated but, as these viruses do not directly infect neurons, an indirect neurotoxic action of the viruses is indicated. Previous experiments have shown that the intra-striatal injection in rats of a synthetic peptide derived from the basic region of the MVV transactivating protein Tat causes considerable neurotoxicity 1 week post-operatively. By in vivo stereotaxic injections of the same synthetic peptide, and subsequent immunocytochemical detection of neurons, astrocytes and microglia, we show that this neurotoxicity displays a distinctive and unusual lesion profile and is evident as rapidly as 0.5 h post-operatively. Furthermore, neuroprotection studies suggest that the early effects of the MVV tat peptide may involve glutamate neurotoxicity via the N-methyl-D-aspartate (NMDA) receptors since the application of dizolcipine (MK801) reduces the volume of the lesion seen at 1 h after the injection of neurotoxic peptide, while L-NAME is ineffective. The mechanism of this early neurotoxicity is thus different from the longer term actions already described.

The nature of the obstructive muscular bundles in double-chambered right ventricle

OBJECTIVE

Our goal was to establish the morphologic nature of the obstructive muscular lesions in double-chambered right ventricle.

METHODS

We based our morphologic observations on 10 normal hearts and on the surgical findings in 26 patients, aged 0.5 to 24 years, with a mean of 6.9 years (SD 5.8 years). In the normal hearts, we measured the distance from the pulmonary valve to the apex of the right ventricle and from the takeoff of the moderator band to the ventricular apex. From angiograms available in 20 patients, using the frontal view, we then measured the distance from the pulmonary valve to the apex of the right ventricle and from the midpoint of the obstructive lesion to the apex of the right ventricle. This permitted calculations of multiple ratios.

RESULTS

In the 10 normal hearts, the moderator band took origin at a mean ratio of 0.48 (SD 0.16) of the ventricular length. On the basis of the angiographic findings, we identified 2 basic forms of double-chambered right ventricle. In 9 patients, the obstructive muscular shelf was positioned low and diagonally across the apical component, with a mean ratio of 0.38 relative to the ventricular length (SD 0.02). In the other 11 patients, the obstructive shelf was high and horizontal, with a mean ratio of 0.27 (SD 0.02). The difference was statistically significant (P =.001). Surgical repair was performed successfully in all 26 patients through a right ventriculotomy.

CONCLUSIONS

Double-chambered right ventricle is the consequence of a high or low muscular division of the apical component of the right ventricle. The abnormal muscular bundle probably represents accentuated septoparietal trabeculations, rather than always being an abnormal moderator band.

The occult pneumothorax: an increasing diagnostic entity in trauma

The increasing use of CT for the evaluation of blunt abdominal trauma has diagnosed undetected pneumothoraces in many patients. We performed a retrospective study at a major trauma center to determine the incidence of occult pneumothorax in the trauma patient. All trauma patients (3121) admitted to a Level I trauma center over a 51-month period were reviewed to determine the incidence of pneumothorax and occult pneumothorax, the method of diagnosis, and treatment. All major trauma patients received a chest X-ray (CXR), whereas 842 patients (27%) underwent an abdominal CT scan. In the 172 patients diagnosed with pneumothorax, 157 abdominal CT scans were performed and 143 were positive for pneumothorax. CXR revealed 49 right-sided pneumothoraces and 58 left-sided pneumothoraces in 95 patients. Abdominal CT scans diagnosed 73 right pneumothoraces and 90 left pneumothoraces in 143 patients. There were 67 patients (71 thoraces) who were seen to have a pneumothorax on abdominal CT scan not seen on admission CXR. This represents 2.2 per cent of all trauma patients and 7.9 per cent of patients with abdominal CT scans. In looking at just trauma patients with pneumothorax, the CT scan was responsible for diagnosing 39 per cent of the patients with a pneumothorax. The occult pneumothorax is being diagnosed more frequently as methods of evaluating and diagnosing trauma patients become more sensitive.

The retinitis pigmentosa GTPase regulator, RPGR, interacts with the delta subunit of rod cyclic GMP phosphodiesterase

Recently, the retinitis pigmentosa 3 (RP3) gene has been cloned and named retinitis pigmentosa GTPase regulator (RPGR). The amino-terminal half of RPGR is homologous to regulator of chromosome condensation (RCC1), the nucleotide exchange factor for the small GTP-binding protein Ran. In a yeast two-hybrid screen we identified the delta subunit of rod cyclic GMP phosphodiesterase (PDEdelta) as interacting with the RCC1-like domain (RLD) of RPGR (RPGR392). The interaction of RPGR with PDEdelta was confirmed by pull-down assays and plasmon surface resonance. The binding affinity was determined to be 90 nM. Six missense mutations at evolutionary conserved residues within the RLD, which were found in RP3 patients, were analyzed by using the two-hybrid system. All missense mutations showed reduced interaction with PDEdelta. A non-RP3-associated missense substitution outside the RLD, V36F, did not abolish the interaction with PDEdelta. PDEdelta is widely expressed and highly conserved across evolution and is proposed to regulate the membrane insertion or solubilization of prenylated proteins, including the catalytic subunits of the PDE holoenzyme involved in phototransduction and small GTP-binding proteins of the Rab family. These results suggest that RPGR mutations give rise to retinal degeneration by dysregulation of intracellular processes that determine protein localization and protein transport.

Short-term benefits of grommet insertion in children

It is commonly acknowledged that otitis media with effusion (OME) can cause behavioural disturbances and that this can be relieved by grommet insertion. However, this widely-held perception has not been documented in the literature. In this study parents were asked to complete a short behavioural questionnaire on the day of the admission and 6 weeks later. A total of 32 children admitted to the Day Care Unit for insertion of grommets at The Royal National Throat, Nose and Ear Hospital, London, UK, were recruited. There was a significant behavioural change, evident by the difference in the scores before and after grommet insertion (P < 0.001).

Outcomes of disabling cervical spine disorders in compensation injuries. A prospective comparison to tertiary rehabilitation response for chronic lumbar spinal disorders

STUDY DESIGN

A prospective, longitudinal cohort study assessing quantitative socioeconomic outcomes of tertiary rehabilitation for chronically disabled patients with cervical spinal disorders compared with those with more common chronic lumbar spinal disorders.

OBJECTIVES

To assess 1-year socioeconomic outcomes of a worst-case cohort of consecutive patients with chronic cervical spinal disorders compared with those of patients with lumbar spinal disorders and to assess differences in an array of variables between those patients who reported any period of work during the posttreatment year and those who did not.

SUMMARY OF BACKGROUND DATA

Few investigators have evaluated outcomes in patients with cervical spinal disorders. None have specifically studied distinctions in socioeconomic outcomes in patients with chronic cervical spinal disorders and in patients with other spinal disorders. Reports of pain are noted to persist in a high percentage of patients with whiplash receiving compensation even 10 years after injury, but the status of work, use of health care resources, financial disputes, or recurrent injury are unknown.

METHODS

A cohort of consecutive chronically disabled patients with spinal disorders (N = 1198) was assessed for prospectively collected demographic, self-report, and physical performance data. A subset of patients (n = 421) with work-related cervical spinal disorders was compared with a group with various lumbar spinal disorders (n = 777). A structured clinical interview was administered 1 year after patients entered an interdisciplinary functional restoration program.

RESULTS

High rates of return to work and continuation of work were recorded in the cervical and lumbar spinal disorder groups, with low rates of recurrent injury, new surgery in the injured area, and use of health care resources. There were no statistically significant differences between the groups. Multivariate analyses showed several variables that differentiated between those patients who had any reported period of work during the post-treatment year versus those who did not in the cervical and the lumbar spinal disorder groups.

CONCLUSIONS

This first large cohort study of outcomes in chronically disabled patients with work-related cervical spinal disorder produced results similar to those found in tertiary functional restoration rehabilitation in chronic lumbar spinal disorders. In spite of poor outcomes reported in the literature for similar cervical and lumbar spinal disorders in patients receiving workers' compensation for disability, successful outcomes can be anticipated after effective rehabilitation, regardless of response to prerehabilitation treatment.

Intra-operative localisation of skull base tumours. A case report using the ISG viewing wand in the management of trigeminal neuroma

Deep-seated skull base tumours provide as much a challenge to the surgeons' skills of localisation as to his technical abilities during the resection. These lesions are frequently inaccessible and lie adjacent to vital structures requiring extensive cerebral retraction for adequate exposure and direct visualisation. The ISG viewing wand is a newly developed image guidance system to aid direction of the operative approach and localisation of intracerebral pathology. We discuss its use in the management of a trigeminal neuroma.

DNA segregation: putting chromosomes in their place

Recent studies provide evidence that bacterial chromosomes are replicated by an enzyme factory, the replisome, located at a fixed position at the center of the cell; the fixed replisome could be a major factor in determining chromosome order in the cell, and may provide the force that drives chromosome segregation.

The epidermoid formation and its affinity to congenital cholesteatoma

The epidermoid formation was reinvestigated in stained step sections of foetal and neonatal temporal bones to assess its relationship to congenital cholesteatoma. Epidermoid formations were found in 88 of 211 temporal bones (42%) at from 12 weeks gestation to 6 months post-partum. The site was usually near the roof of the anterolateral epitympanum at an average of 389 microns anterior to the anterior edge of the tympanic membrane. Seven epidermoid formations however, were sited on the medial anterosuperior tympanic membrane surface. The mean surface diameter of epidermoid formations was 242 microns. Some were greater than 1500 microns, which approaches the size of small congenital cholesteatomas. They are often in proximity to a developmental epithelial fold which could close off to produce a cyst. These features support the concept that the epidermoid formation is a precursor of the small anterosuperior congenital cholesteatoma.

Evidence for interspecies gene transfer in the evolution of 2,4-dichlorophenoxyacetic acid degraders

Small-subunit ribosomal DNA (SSU rDNA) from 20 phenotypically distinct strains of 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria was partially sequenced, yielding 18 unique strains belonging to members of the alpha, beta, and gamma subgroups of the class Proteobacteria. To understand the origin of 2,4-D degradation in this diverse collection, the first gene in the 2,4-D pathway, tfdA, was sequenced. The sequences fell into three unique classes found in various members of the beta and gamma subgroups of Proteobacteria. None of the alpha-Proteobacteria yielded tfdA PCR products. A comparison of the dendrogram of the tfdA genes with that of the SSU rDNA genes demonstrated incongruency in phylogenies, and hence 2,4-D degradation must have originated from gene transfer between species. Only those strains with tfdA sequences highly similar to the tfdA sequence of strain JMP134 (tfdA class I) transferred all the 2,4-D genes and conferred the 2,4-D degradation phenotype to a Burkholderia cepacia recipient.

The central lysine in the P-loop motif of the Escherichia coli DnaA protein is essential for initiating DNA replication from the chromosomal origin, oriC, and the F factor origin, oriS, but is dispensable for initiation from the P1 plasmid origin, oriR

The Escherichia coli DnaA protein is essential for initiation of DNA replication from the chromosomal origin, oriC, and from certain plasmid origins such as oriR of P1, oriS of F, and ori of pSCS101. The DnaA protein binds ATP with high affinity and contains a P-loop motif assumed to be the binding site. Three mutations in the E. coli dnaA gene were constructed by oligonucleotide-directed mutagenesis that changed amino acids in the P-loop. A DnaA protein, K178T, in which the central lysine was changed to the smaller amino acid threonine, was able to initiate DNA replication from P1 oriR, but was unable to initiate replication from E. coli oriC or F oriS in vivo. Mutant and wild-type DnaA proteins were overexpressed, partially purified, and tested for replication activity in vitro. The K178T DnaA protein could initiate replication from oriR, although with a decreased activity compared to the wild-type DnaA protein. No replication activity was detected for this mutant protein from oriC. The different responses of the oriR and oriC replicons to the K178T DnaA protein indicate that the role of DnaA is different in the two systems.

Overview and meta-analysis of randomised trials of amiodarone in chronic heart failure

Unlike other antiarrhythmic class I drugs, amiodarone showed in preliminary studies, benefits also in patients with left ventricular dysfunction. These positive results have induced the development of large randomised controlled studies: their results are reviewed and the controversial points are discussed. In a meta-analysis of randomised controlled trials the use of amiodarone in heart failure was associated with an approximate 20 to 25% reduction in deaths. However, amiodarone was also associated with a 120 to 124% increase in side effects.

An investigation of the interrelationship between manipulative therapy-induced hypoalgesia and sympathoexcitation

OBJECTIVE

To investigate a proposed model in which manipulative therapy produces a treatment-specific initial hypoalgesic and sympathoexcitatory effect by activating a descending pain inhibitory system. The a priori hypothesis tested was that manipulative therapy produces mechanical hypoalgesia and sympathoexcitation beyond that produced by placebo or control. Furthermore, these effects would be correlated, thus supporting the proposed model.

DESIGN

A randomized, double-blind, placebo-controlled, repeated-measures study of the initial effect of treatment.

SETTING

Clinical neurophysiology laboratory.

SUBJECTS

Twenty-four subjects (13 women and 11 men; mean age, 49 yr) with chronic lateral epicondylalgia (average duration, 6.2 months).

INTERVENTION

Cervical spine lateral glide oscillatory manipulation, placebo and control.

OUTCOME MEASURES

Pressure pain threshold, thermal pain threshold, pain-free grip strength test, upper limb tension test 2b, skin conductance, pileous and glabrous skin temperature and blood flux.

RESULTS

Treatment produced hypoalgesic and sympathoexcitatory changes significantly greater than those of placebo and control (p < .03). Confirmatory factor-analysis modeling, which was performed on the pain-related measures and the indicators of sympathetic nervous system function, demonstrated a significant correlation (r = .82) between the latencies of manipulation-induced hypoalgesia and sympathoexcitation. The Lagrange Multiplier test and Wald test indicated that the two latent factors parsimoniously and appropriately represented their observed variables.

CONCLUSION

Manual therapy produces a treatment-specific initial hypoalgesic and sympathoexcitatory effect beyond that of placebo or control. The strong correlation between hypoalgesic and sympathoexcitatory effects suggests that a central control mechanism might be activated by manipulative therapy.

Characterization and optimization of in vitro assay conditions for (1,3)beta-glucan synthase activity from Aspergillus fumigatus and Candida albicans for enzyme inhibition screening

(1,3)Beta-D-glucan synthase (E.C.2.4.1.34. UDP-glucose: 1,3-beta-D-glucan 3-beta-glucosyl transferase) catalyzes the polymerization of glucose ([1-3]-beta-linkages) using UDP-glucose as substrate. We have determined optimal in vitro conditions for the assay of (1,3)beta-glucan synthase activity from Aspergillus fumigatus and Candida albicans. These included lysis of cells in the following for C. albicans, 100 mM HEPES, pH 8.0, 10 microM guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS), 2 mM ethylenediaminetetraacetic acid (EDTA), disodium salt, 5 mM NaF, 250 mM sucrose, and 10 mM NaH2PO4; and for A. fumigatus, 50 mM HEPES, 10mM EDTA, 750 mM sucrose, 10 mM NaH2PO4, 100 mM cellobiose and 50 microM GTPgammaS. Resulting low-speed supernatants were used as enzyme sources to determine the optimal in vitro assay conditions. We have characterized the resulting enzyme activities and tested the optimized assays with known (1,3)beta-glucan synthase inhibitors including cilofungin, papulacandin, aculeacin A, and echinocandin B. We have used both optimized assays to screen > 1000 extracts of marine macroorganisms and, using bioassay-guided purification, have identified (1,3)beta-glucan synthase inhibitors.