Lycra garments designed for patients with upper limb spasticity: mechanical effects in normal subjects

OBJECTIVE

To assess the stretch of pronator muscles produced by a specifically designed upper-limb Lycra garment that could have a better acceptability than rigid splints in treating upper-limb spasticity.

DESIGN

Double-blind comparison among three garments. They were designed to produce a supinating, a pronating, and no torsional force, and were individually manufactured and tested in 10 healthy volunteers.

MAIN OUTCOME MEASURE

Angular position and passive rotational stiffness of the forearm were measured with and without each of the garments immediately after the garment was fitted and every hour for 6 hours.

RESULTS

When put on by a trained person, the supinator garment supinated the forearm in all subjects (mean, 17 degrees; p < .01; range, 5 degrees to 44 degrees) while the pronator garment pronated the forearm in 8 of 10 subjects (mean, 5 degrees; p < .01). These effects gradually decayed over 6 hours, as garment position was not readjusted. Passive rotational stiffness of the forearm increased by about 30% with each type of garment. The garments designed to produce no torsional force exerted no intrinsic rotational effect.

CONCLUSION

Individually made Lycra garments can produce continuous stretch of muscles for several hours and may be useful in the treatment of spasticity. The garments, however, must be put on by a trained person and their position adjusted when necessary.

Cost-of-illness of scleroderma: the case for rare diseases

OBJECTIVE

To determine the societal costs of scleroderma (SSc), a rare chronic connective tissue disease that affects approximately 98,000 Americans. Lack of reliable national databases limit rare disease cost studies, and this study suggests methods of using multiple data sources to assess the costs of rare diseases.

METHODS

Primary and secondary data sources were used to calculate direct and indirect costs of SSc, including discounted lifetime mortality and morbidity costs. A prevalence-based, human capital approach was used. Sensitivity analyses were used to vary parameters that are uncertain, such as prevalence, mortality, and labor costs.

RESULTS

Annual direct and indirect costs of SSc in the United States are $1.5 billion. Morbidity represents the major cost burden, with costs of $819 million (56%) of total costs. The current value of lifetime earnings lost was $179 million (12%) or $300,000 per death. Direct costs were $462 million (32%) or $4,731 per person annually, indicating that costs are spread over the long disease duration.

CONCLUSIONS

This study provides one model for the assessment of rare disease costs. Triangulation of data sources and sensitivity analyses are important for determining the costs of rare diseases. The high cost of SSc, despite its low prevalence, suggests that the burden of rare chronic diseases can be high. The high morbidity costs reflect the young age of onset of the disease as well as the need for treatments to decrease morbidity costs. Local shared databases and national surveys are needed to improve cost estimates of rare diseases.

Stabilization of microtubule dynamics by estramustine by binding to a novel site in tubulin: a possible mechanistic basis for its antitumor action

The cellular targets for estramustine, an antitumor drug used in the treatment of hormone-refractory prostate cancer, are believed to be the spindle microtubules responsible for chromosome separation at mitosis. Estramustine only weakly inhibits polymerization of purified tubulin into microtubules by binding to tubulin (Kd, approximately 30 microM) at a site distinct from the colchicine or the vinblastine binding sites. However, by video microscopy, we find that estramustine strongly stabilizes growing and shortening dynamics at plus ends of bovine brain microtubules devoid of microtubule-associated proteins at concentrations substantially below those required to inhibit polymerization of the microtubules. Estramustine strongly reduced the rate and extent both of shortening and growing, increased the percentage of time the microtubules spent in an attenuated state, neither growing nor shortening detectably, and reduced the overall dynamicity of the microtubules. Significantly, the combined suppressive effects of vinblastine and estramustine on the rate and extent of shortening and dynamicity were additive. Thus, like the antimitotic mechanisms of action of the antitumor drugs vinblastine and taxol, the antimitotic mechanism of action of estramustine may be due to kinetic stabilization of spindle microtubule dynamics. The results may explain the mechanistic basis for the benefit derived from combined use of estramustine with vinblastine or taxol, two other drugs that target microtubules, in the treatment of hormone-refractory prostate cancer.

Inhibition of mitosis and microtubule function through direct tubulin binding by a novel antiproliferative naphthopyran LY290181

The mechanism of action of a novel antiproliferative compound LY290181 [2-amino-4-(3-pyridyl)-4H-naphtho(1,2-b)pyran-3-carbonitrile] was characterized. LY290181 is a potent inhibitor of cell proliferation, producing 50% inhibition of vascular smooth muscle, endothelial, Chinese hamster ovary, HeLa, and human erythroleukemia cells at concentrations of 8-40 nM. Cell cycle analysis showed that LY290181 caused accumulation of smooth muscle cells at the G2/M phase and induced mitotic arrest in Chinese hamster ovary cells and HeLa cells. At low concentrations (3-30 nM), LY290181 blocked transition of cells from metaphase to anaphase and disrupted mitotic spindle organization. At high concentrations (>/=100 nM), LY290181 produced a concentration-dependent loss of cytoplasmic and spindle microtubules. LY290181 inhibited the polymerization of purified bovine brain microtubule protein into microtubules, and it depolymerized preformed microtubules. Using tubulin-1-anilino-8-naphthalene sulfonate complex fluorescence, we have shown that LY290181 directly interacted with tubulin in a unique manner. These studies show that LY290181 induces cell growth arrest in prometaphase/metaphase, and tubulin appears to be its molecular target.

Late disruption of Dacron aortic grafts

Aneurysmal degeneration, or complete disruption of Dacron grafts (as opposed to anastomotic complications such as pseudoaneurysms), are not expected by vascular surgeons. We have noted two such cases. A 65-year-old male who had an aortobifemoral, double-velour Dacron graft in 1980, presented in 1995 with a large, pulsatile mass in the right lower quadrant, caused by disruption of the mid-portion of the right limb of the Dacron graft. In a second case, a 68-year-old man had a Dacron aortobifemoral graft placed in 1968 which developed diffuse aneurysmal defects, noted clinically in 1987. Both patients had successful graft replacement. A review of the literature indicates that this complication, although unusual, has been noted periodically. Between 1970 and 1996, we identified 11 case reports of aortic Dacron graft rupture, including knitted Dacron (4), double velour (3), woven (1), knitted thin wall (1), and unspecified Dacron grafts (2). An inquiry to the FDA disclosed another 68 cases of Dacron graft failure in addition to those reported in the surgical literature. We present these cases to alert vascular surgeons of the possibility of Dacron graft degeneration, as late as 19 years after implantation. Diagnosis of the complication is readily apparent by clinical examination and imaging studies, which display an aneurysm of the graft remote from the anastomoses.

SH3 domain-mediated interactions involving the phox components of the NADPH oxidase

OBJECTIVE AND DESIGN

To derive a model describing the SH3 domain-mediated assembly of the activated NADPH oxidase.

MATERIALS

Recombinant SH3 domain and Pro-rich fusion proteins were used to investigate potential co-associations.

METHODS

Interactions were assessed using biotinylated overlay assays and the yeast two hybrid system. Association with p47phox from cell lysates was examined by immunoblot analysis.

RESULTS

The association between p47- and p22phox involves the SH3 domains of p47phox functioning in tandem. The Prorich motif in p47phox interacts with both p40phox and the COOH-terminal SH3 domain of p67phox.

CONCLUSIONS

In the resting cell, the Pro-rich motif of p47phox interacts with the SH3 domain of p40phox, which in turn associates with p67phox. Upon activation, the p47-p40phox regulatory complex dissociates, permitting the association of p47phox with the COOH-terminal SH3 domain of p67phox. This complex translocates to the plasma membrane and associates with cytochrome b558, via interaction of the tandem SH3 domains of p47phox with the p22phox Pro-rich motif.

A survey for antibodies to Lassa virus among health workers in Nigeria

A study was conducted among 552 health workers at 6 health facilities in Nigeria. Lassa virus immunoglobulin (Ig) G antibody was detected in 12.3%, using an enzyme-linked immunosorbent assay. Antibody prevalence in the 6 health centres ranged from 1.2% to 27.3%. Prevalences were higher in primary and secondary health facilities than in tertiary centres. Seroprevalences ranged from 1.7% to 23.7% among different occupational groups of health workers; the highest observed antibody prevalence was among ward aids. Lassa virus IgM antibody, indicating recent infection, was present in 6 of the health workers, 5 of whom were ward aids and one was a nurse. All of the health workers with specific IgM came from a single facility in Lafia, sampled during an outbreak of Lassa fever.

The quality management jigsaw

The current scene in Australia, as in a large part of the developed world, in relation to the subject of quality management in health care, is characterized by confusion, blurred objectives, patchy involvement and very high opportunity costs. Much of the confusion is caused by a failure to understand or use correctly the bewildering array of terminology that characterizes what is becoming a new discipline in its own right. A series of simple definitions permits the reader to understand what the author is attempting to say. The paper also provides a conceptual framework for the implementation of quality management in hospitals: a jigsaw of activity which hospitals have some difficulty conceptualizing and without which hospitals will never be able to respond seriously to the challenge of assuring quality.

Prenatal diagnosis in merosin-deficient congenital muscular dystrophy

Prenatal diagnosis was carried out in five merosin-deficient congenital muscular dystrophy (CMD) families. We studied both laminin-alpha 2 chain expression in trophoblast using immunocytochemistry and linkage analysis to the LAMA2 locus. In four families there was good agreement between the immunocytochemistry and linkage analysis results: in one case the trophoblast was negative for LAMA2 expression and haplotype analysis suggested the foetus was affected; in the other three cases the laminin-alpha 2 chain expression was normal and foetuses were found to be carriers. In the remaining family, a case of partial laminin-alpha 2 chain expression, the immunostaining of the trophoblast was weaker compared to the control. Linkage analysis, however, could not be performed because of maternal DNA contamination. After termination of pregnancy, the foetal muscle was studied and suggested weak laminin-alpha 2 chain expression. The haplotype analysis however showed that the foetus was probably a carrier, unless a double recombinant event had occurred. We conclude that a combination of immunocytochemistry and linkage analysis can be used for the prenatal diagnosis of merosin deficient CMD. The results are easy to interpret in families with total absence of the protein, while caution is required when dealing with families where partial expression occurs.

Antigen processing and presentation by human trophoblast-derived cell lines

The trophoblast-derived choriocarcinoma cell lines JEG-3 and JAR express the nonclassical MHC class I molecules HLA-G (JEG-3) or, at a low level, HLA-E (JAR), but lack expression of the classical MHC class I molecules HLA-A and HLA-B. Expression of these nonclassical MHC class I genes was found to coincide with expression of the genes encoding the peptide transporter associated with Ag processing (TAP). In immunoprecipitation studies, a physical interaction between the TAP complex and HLA-G or HLA-E could be demonstrated. To investigate whether trophoblast-derived cell lines were capable of peptide processing, transport, and loading of MHC class I molecules, HLA-A*0201-expressing transfectants of JEG-3 and JAR were used for functional studies. These transfectants were recognized by both allospecific cytotoxic T cell clones and, after viral infection, by an influenza A matrix peptide-specific cytotoxic T cell clone, indicating that these trophoblast-derived cell lines were capable of presenting endogenously derived peptides in the context of HLA-A*0201. From these observations, it can be inferred that the TAP complex and other molecules involved in Ag processing and presentation by MHC class I molecules are functionally active in these trophoblast-derived cell lines. This implies that trophoblasts are able to provide antigenic peptides for presentation by nonclassical MHC class I molecules that are naturally expressed by this cell type.

Antigen processing and presentation by human trophoblast-derived cell lines

The trophoblast-derived choriocarcinoma cell lines JEG-3 and JAR express the nonclassical MHC class I molecules HLA-G (JEG-3) or, at a low level, HLA-E (JAR), but lack expression of the classical MHC class I molecules HLA-A and HLA-B. Expression of these nonclassical MHC class I genes was found to coincide with expression of the genes encoding the peptide transporter associated with Ag processing (TAP). In immunoprecipitation studies, a physical interaction between the TAP complex and HLA-G or HLA-E could be demonstrated. To investigate whether trophoblast-derived cell lines were capable of peptide processing, transport, and loading of MHC class I molecules, HLA-A*0201-expressing transfectants of JEG-3 and JAR were used for functional studies. These transfectants were recognized by both allospecific cytotoxic T cell clones and, after viral infection, by an influenza A matrix peptide-specific cytotoxic T cell clone, indicating that these trophoblast-derived cell lines were capable of presenting endogenously derived peptides in the context of HLA-A*0201. From these observations, it can be inferred that the TAP complex and other molecules involved in Ag processing and presentation by MHC class I molecules are functionally active in these trophoblast-derived cell lines. This implies that trophoblasts are able to provide antigenic peptides for presentation by nonclassical MHC class I molecules that are naturally expressed by this cell type.

The relationship between nonorganic signs and centralization of symptoms in the prediction of return to work for patients with low back pain

BACKGROUND AND PURPOSE

The purpose of this study was to assess the relationship between the nonorganic signs (Waddell scores) of patients with low back pain, their response to repetitive end-range lumbar spine test movements (centralization of symptoms), and the rate of return to work at a 6-month follow-up.

SUBJECTS

Patients were assessed at five locations of the Canadian Back Institute. A consecutive sample of 126 patients with low back pain, with or without referred leg pain, was selected and reviewed.

METHODS

Physical therapists assessed patients' responses to repetitive test movements (centralization), as described by McKenzie, and tested the patients for nonorganic signs (Waddell scores). Therapists completed a data sheet that classified patients as either those who centralize their symptoms or those who do not centralize their symptoms and recorded their Waddell scores. Although the patients were classified at assessment, they remained in treatment. All patients followed a structured Canadian Back Institute protocol of active exercise, regardless of centralization status or Waddell score.

RESULTS

The inability to centralize symptoms indicated a decreased likelihood of returning to work, regardless of the Waddell score. A high Waddell score predicted a poor chance of returning to work, regardless of the patients' ability to centralize symptoms.

CONCLUSION AND DISCUSSION

A high Waddell score appears to be the best predictor of outcome, as indicated by return to work.

Taxol differentially modulates the dynamics of microtubules assembled from unfractionated and purified beta-tubulin isotypes

Substoichiometric binding of taxol to tubulin in microtubules potently suppresses microtubule dynamics, which appears to be the most sensitive antiproliferative mechanism of taxol. To determine whether the beta-tubulin isotype composition of a microtubule can modulate sensitivity to taxol, we measured the effects of substoichiometric ratios of taxol bound to tubulin in microtubules on the dynamics of microtubules composed of purified alphabeta(II)-, alphabeta(III)-, or alphabeta(IV)-tubulin isotypes and compared the results with the effects of taxol on microtubules assembled from unfractionated tubulin. Substoichiometric ratios of bound taxol in microtubules assembled from purified beta-tubulin isotypes or unfractionated tubulin potently suppressed the shortening rates and the lengths shortened per shortening event. Correlation of the suppression of the shortening rate with the stoichiometry of bound taxol revealed that microtubules composed of purified alphabeta(II)-, alphabeta(III)-, and alphabeta(IV)-tubulin were, respectively, 1.6-, 7.4-, and 7.2-fold less sensitive to the effects of bound taxol than microtubules assembled from unfractionated tubulin. These results indicate that taxol differentially modulates microtubule dynamics depending upon the beta-tubulin isotype composition. The results are consistent with recent studies correlating taxol resistance in tumor cells with increased levels of beta(III0- and beta(IV)-tubulin expression and suggest that altered cellular expression of beta-tubulin isotypes can be an important mechanism by which tumor cells develop resistance to taxol.

Suppression of microtubule dynamics by LY290181. A potential mechanism for its antiproliferative action

LY290181, 2-amino-4-(3-pyridyl)-4H-naphtho(1,2-b)pyran-3-carbonitrile, is a potent antiproliferative compound that blocks cells in the G2/M phase of the cell cycle by an apparent action on microtubules. In the present work we found that LY290181 bound to tubulin with high affinity (1 mol of LY290181 per mol of tubulin dimer; Ka, 3.8 x 10(5) M-1) and that it did not appear to bind at the colchicine or vinblastine-binding sites. LY290181 strongly stabilized microtubule dynamics as determined by video microscopy. It reduced the rate and extent of growing and shortening, reduced the catastrophe frequency and increased the rescue frequency, and increased the percentage of time the microtubules spent in an attenuated state. At the lowest effective LY290181 concentrations (0.1-0.3 microM), suppression of dynamics occurred with little reduction in polymer mass. However, at higher concentrations, LY290181 strongly reduced the polymer mass with half-maximal inhibition at a concentration of 0.75 microM. We suggest that LY290181 may exert its antiproliferative activity by stabilizing spindle microtubule dynamics by binding to tubulin at a novel site.

Daily changes in plasma and amniotic fluid prolactin during the last third of pregnancy in the baboon

Alterations in plasma and amniotic fluid prolactin (PRL) levels have not been previously described in the pregnant baboon. In addition, PRL increases dramatically in response to estrogens and thus might be a good marker for expression of estrogen's biologic action. Therefore, the purpose of this study was to characterize the changes in plasma and amniotic fluid PRL with advancing gestational age and assess whether there was a correlation between plasma estradiol and PRL levels. A tethered pregnant baboon model was utilized for these studies. Blood was collected from five animals every day at 0900-1000 h (AM value) and 1800 h (PM value) from 125 to 135 days of pregnancy until delivery. Amniotic fluid was collected every day in the morning. Samples were analyzed by RIA for PRL, estradiol, and progesterone. PRL did not change with advancing gestational age. However, PRL showed a significant diurnal variation, with the PM values significantly higher (p < 0.05) than the AM values. In contrast to findings for PRL, AM values for estradiol and progesterone were on average higher that PM values (p < 0.05). A significant correlation was observed between the log10 estradiol (AM+PM) and log10 PRL (AM) from the following day (r = 0.52; p < 0.05). Finally, amniotic fluid PRL was present in high concentrations (200-400 ng/ml) but did not vary with gestational age. In conclusion, PRL, estradiol, and progesterone show distinct diurnal variations during the last one-third of pregnancy in the baboon. In addition, plasma PRL is positively correlated with estradiol.

A senior volunteer/home care agency national collaboration: assessment of the partnership

This research has focused on a partnership between a private sector home health care entity, the Visiting Nurse Associations of America (VNAA) and the public sector Senior Companion Program (SCP) of the domestic volunteer agency now a part of the Corporation for National and Community Service. This research examined the partnerships between the two agencies in 18 local demonstration sites in order to assess how a home health agency worked. Specific areas reviewed were administration of the partnership, communication patterns between the agencies, areas of conflict, the future of the liaison, and how effectively volunteer performance matched original expectations.

Agenesis of the corpus callosum in Turner syndrome with ring X

An 8-year-old girl with Turner syndrome and 45,X/46,X,r(X) mosaicism was found to have agenesis of the corpus callosum and various other characteristics including 'kabuki makeup' facial features and mild learning disability. Only two other cases of Turner syndrome associated with agenesis of the corpus callosum have been reported, both in patients with a 45,X karyotype. In both of those patients the constellation of signs differed from those of the present patient in a number of ways. It remains to be confirmed whether there is a higher incidence of CNS malformation in girls who have Turner syndrome with a ring X than has been reported for girls with Turner syndrome in general.

Functional interactions between the proline-rich and repeat regions of tau enhance microtubule binding and assembly

Tau is a neuronal microtubule-associated protein that promotes microtubule assembly, stability, and bundling in axons. Two distinct regions of tau are important for the tau-microtubule interaction, a relatively well-characterized "repeat region" in the carboxyl terminus (containing either three or four imperfect 18-amino acid repeats separated by 13- or 14-amino acid long inter-repeats) and a more centrally located, relatively poorly characterized proline-rich region. By using amino-terminal truncation analyses of tau, we have localized the microtubule binding activity of the proline-rich region to Lys215-Asn246 and identified a small sequence within this region, 215KKVAVVR221, that exerts a strong influence on microtubule binding and assembly in both three- and four-repeat tau isoforms. Site-directed mutagenesis experiments indicate that these capabilities are derived largely from Lys215/Lys216 and Arg221. In marked contrast to synthetic peptides corresponding to the repeat region, peptides corresponding to Lys215-Asn246 and Lys215-Thr222 alone possess little or no ability to promote microtubule assembly, and the peptide Lys215-Thr222 does not effectively suppress in vitro microtubule dynamics. However, combining the proline-rich region sequences (Lys215-Asn246) with their adjacent repeat region sequences within a single peptide (Lys215-Lys272) enhances microtubule assembly by 10-fold, suggesting intramolecular interactions between the proline-rich and repeat regions. Structural complexity in this region of tau also is suggested by sequential amino-terminal deletions through the proline-rich and repeat regions, which reveal an unusual pattern of loss and gain of function. Thus, these data lead to a model in which efficient microtubule binding and assembly activities by tau require intramolecular interactions between its repeat and proline-rich regions. This model, invoking structural complexity for the microtubule-bound conformation of tau, is fundamentally different from previous models of tau structure and function, which viewed tau as a simple linear array of independently acting tubulin-binding sites.