Epidemiology of back injury in university hospital nurses from review of workers' compensation records and a case-control survey

Reviewing Workers' Compensation records for back injury from a large university hospital for a 2-year period, we found a yearly incidence of lost work time back injury among nurses of 2.0% per year, exceeded only by physical plant staff, who had a rate of 3.5%. Nurses' aides had an injury rate 3.3-fold higher than registered nurses and licensed practical nurses and higher than any other occupational group. We compared 100 cases of nurses with back injury in the previous 2 years with 197 noninjured control subjects using a mailed 40-item questionnaire. Multivariate logistic modelling showed that prior nonback injury and performing combined lifting activities were statistically significant risk factors for back injury, and being overweight approached significance, after adjusting for the effects of age, gender, and each of the evaluated risk factors.

Ectopic Hoxa-1 induces rhombomere transformation in mouse hindbrain

Homeobox genes are expressed with a specific spatial and temporal order, which is essential for pattern formation during the early development of both invertebrates and vertebrates. Here we show that widespread ectopic expression of the Hoxa-1 (Hox 1.6) gene directed by a human beta-actin promoter in transgenic mice is embryolethal and produces abnormal phenotypes in a subset of domains primarily located in anterior regions. Interestingly, this abnormal development in the Hoxa-1 transgenic mice is associated with ectopic expression of the Hoxb-1 (Hox 2.9) gene in select hindbrain regions. At gestation day 9.5, two domains of strong Hoxb-1 expression are found in the anterior region of the hindbrains of Hoxa-1 transgenic embryos. One region represents the normal pattern of Hoxb-1 expression in rhombomere 4 and its associated migrating neural crest cells, while another major domain of Hoxb-1 expression consistently appears in rhombomere 2. Similar ectopic domains of beta-galactosidase activity are detected in dual transgenic embryos containing both beta-actin/Hoxa-1 transgene and a Hoxb-1/lacZ reporter construct. Expression of another lacZ reporter gene that directs beta-galactosidase activity predominantly in rhombomere 2 is suppressed in the Hoxa-1 transgenic embryos. We have also detected weaker and variable ectopic Hoxb-1 expression in rhombomeres 1, 3 and 6. No ectopic Hoxb-1 expression is detected in rhombomere 5 and the expression of Hoxa-3 and Krox-20 in this region is unchanged in the Hoxa-1 transgenic embryos. While no obvious change in the morphology of the trigeminal or facial-acoustic ganglia is evident, phenotypic changes do occur in neurons that emanate from rhombomeres 2 and 3 in the Hoxa-1 transgenic embryos. Additionally, alterations in the pattern of Hoxa-2 and Hoxb-1 expression in a subpopulation of neural crest cells migrating from the rhombomere 2 region are detected in these transgenics. Taken together, these data suggest that ectopic Hoxa-1 expression can reorganize select regions of the developing hindbrain by inducing partial transformations of several rhombomeres into a rhombomere-4-like identity.

Suppression of the allogeneic response by human IL-10: a critical role for suppression of a synergy between IL-2 and TNF-alpha

The effect of IL-10 on T-cell activation by alloantigens in primary mixed lymphocyte reaction (MLR) was examined. IL-10 strongly suppressed proliferation and cytokine synthesis observed in this reaction. To determine the cytokine synthesis inhibition that was critical for the IL-10 induced suppression of proliferation in MLR, the effect of exogenous cytokines (IL-1 alpha, IL-1 beta, IL-2, IL-4, IL-6, IFN-gamma, or TNF-alpha) on this suppression was examined. None of these cytokines, when used at high concentration, was able to completely restore proliferation in the MLR to the levels observed in the absence of IL-10. However, IL-2 and TNF-alpha, when added alone at high concentration, could partially overcome the IL-10 induced suppression of proliferation in MLR. Moreover, when a combination of IL-2 and TNF-alpha was added at suboptimal doses to IL-10-suppressed MLR, complete restoration of the proliferative response was obtained. The ability of IL-10 to suppress proliferation in MLR was dependent on the type of cells used as stimulators. Thus, IL-10 suppressed proliferation in MLR when allogeneic normal peripheral blood mononuclear cells (PBMC), highly purified monocytes or B cells, were used, but not when B-cell lines were used as stimulators. Investigation of the effect of IL-10 on cytokine synthesis revealed that when B-cell lines were used as stimulators of MLR, IL-10 suppressed IFN-gamma and IL-2 synthesis but was unable to suppress TNF-alpha production. In contrast, CSA, which inhibited proliferation in MLR induced by B-cell lines, also inhibited TNF-alpha. IL-2 and IFN-gamma synthesis. Together these data suggest that the suppression of MLR by IL-10 requires the effective inhibition of both IL-2 and TNF-alpha production to suppress a synergy between these two cytokines.

Solution conformation of a cyclic neurokinin antagonist: a NMR and molecular dynamics study

The solution structure of a hexapeptide, cyclo (Gln-Trp-Phe-Gly-Leu-Met), which is a selective NK-2 antagonist, has been studied by a combination of two-dimensional nmr and molecular dynamics (MD) techniques. The simulation based on nmr and MD data resulted in the convergence to a family of structures. Free molecular dynamics for 50 ps in the presence of DMSO solvent molecules shows that the structure is energetically stable. One intramolecular hydrogen bond between the amide proton of Gln and the carbonyl oxygen of Gly was revealed. This result is consistent with the results from the measurement of the temperature coefficient of the amide protons. The extent of intermolecular hydrogen bonding between the amide protons of the peptide and DMSO was also revealed by the free MD simulation. The resulting structure of the cyclic peptide contains a variation type I' beta-turn in the Gly-Leu-Met-Gln segment. Comparison of the structure of this peptide with that of other NK-2 antagonist cyclic hexapeptides was made, and the activity of cyclic antagonists appears to be inversely related to the conformational rigidity of the cyclic peptides.

[Influence of refined amorphophallus konjac on osteoporosis in the aged female rats: a preliminary bone histomorphometric analysis]

The hypolipidaemic and antisteatotic effects of refined amorphophallus konjac (RAK) have been reported. In order to further evaluate the effect of RAK on osteoporosis in the aged female SD rats, forty one month aged female SD rats were divided into three groups: a normal diet group (S), another normal diet group (A) and a test group (B) in which the animals were fed on a diet similar to that of the normal diet group with the addition of RAK at a dosage of 1%. At the end of the sixth month of the diet treatment, all the animals in S group were killed. Animals of the other two groups were sacrificed at the end of experiments for 18 months. Blood and right femora samples were collected for serum Ca, P, and for bone mineral contents (BMC), respectively. Inorganic matter (ash content), and calcium and phosphorus contents of the left femur were measured. Meanwhile, undecalcified sections of left tibia were processed for bone histomorphometry. The results showed that trabecular bone volume (Vv), trabecular perimeters (TRP), bone mineral contents (BMC) as well as the Ca, P contents of bone were lower in A and B than in S, but no significance was found between A and B in all of the above indices. These data exhibited: (1) Similar to the postmenopausal osteoporosis in aged women, the bone mass of the aged female rats was markedly lost in A and B. (2) A diet treatment with 1% RAK would not aggravate osteoporosis.

Use of antibodies to identify satellite cells with a light microscope

Satellite cells are essential for the growth and regeneration of skeletal muscles but the study of them has been difficult due to the need to use an electron microscope. This article describes a method which enables satellite cells to be identified with a light microscope. Satellite cells were distinguished from: (1) myonuclei on the basis of whether the nuclei were inside or outside the plasmalemma of a fiber (stained with antidystrophin); and (2) interstitial cells depending on whether they were inside or outside of a fiber's basal lamina (stained with anticollagen IV). Some satellite cells were stained by the antidystrophin which further aided their identification. The question of whether all satellite cells are myogenic has been investigated and discussed. This method will facilitate the study of satellite cells in biopsies of human muscles and the estimation of satellite cell number in laboratory animals.

Community-based psychiatric rehabilitation in Shanghai. Facilities, services, outcome, and culture-specific characteristics

This paper describes the community mental health services in Shanghai, analyses the effectiveness of these services, and discusses their culture-specific characteristics. It reports on a prospective, matched-control study of the three most important types of service: a community follow-up programme in psychiatric out-patient clinics at primary-level general hospitals, 'guardianship networks' operated by non-professional volunteers, and work therapy stations. In total 308 pairs of subjects completed the study. Using Chinese versions of the Disability Assessment Schedule to assess impairment in psychosocial functioning and the Present State Examination to assess the levels of positive and negative symptoms, ten blind evaluators who had excellent inter-rater reliability assessed the functioning of subjects at enrollment and every six months for the next two years. Over the two years, symptoms and social functioning improved in the treatment groups and deteriorated in the control groups. Thus these community psychiatric services have the dual benefit of promoting rehabilitation and preventing psychosocial deterioration.

Deletion within the Src homology domain 3 of Bruton's tyrosine kinase resulting in X-linked agammaglobulinemia (XLA)

The gene responsible for X-linked agammaglobulinemia (XLA) has been recently identified to code for a cytoplasmic tyrosine kinase (Bruton's agammaglobulinemia tyrosine kinase, BTK), required for normal B cell development. BTK, like many other cytoplasmic tyrosine kinases, contains Src homology domains (SH2 and SH3), and catalytic kinase domain. SH3 domains are important for the targeting of signaling molecules to specific subcellular locations. We have identified a family with XLA whose affected members have a point mutation (g-->a) at the 5' splice site of intron 8, resulting in the skipping of coding exon 8 and loss of 21 amino acids forming the COOH-terminal portion of the BTK SH3 domain. The study of three generations within this kinship, using restriction fragment length polymorphism and DNA analysis, allowed identification of the mutant X chromosome responsible for XLA and the carrier status in this family. BTK mRNA was present in normal amounts in Epstein-Barr virus-induced B lymphoblastoid cell lines established from affected family members. Although the SH3 deletion did not alter BTK protein stability and kinase activity of the truncated BTK protein was normal, the affected patients nevertheless have a severe B cell defect characteristic for XLA. The mutant protein was modeled using the normal BTK SH3 domain. The deletion results in loss of two COOH-terminal beta strands containing several residues critical for the formation of the putative SH3 ligand-binding pocket. We predict that, as a result, one or more crucial SH3 binding proteins fail to interact with BTK, interrupting the cytoplasmic signal transduction process required for B cell differentiation.

Randomised-control trial of family intervention for 78 first-episode male schizophrenic patients. An 18-month study in Suzhou, Jiangsu

At the time of discharge from their first stay in psychiatric hospital, 78 male schizophrenic patients were randomly assigned to a family intervention (experimental) group or a 'standard care' control group and were followed for the next 18 months. The family intervention consisted of both group and individual counselling sessions every 1-3 months that focused on education about the illness and on methods of dealing with the patient. There was a significantly lower rate of hospital readmission in the family intervention group than in the control group (15.4% versus 53.8%, chi 2 = 12.75, P < 0.01), and the mean hospital-free period for those who were readmitted was significantly longer in the experimental group than in the control group (245 days versus 130 days, t = 2.91, P < 0.01). Moreover, the clinical status and overall level of functioning in patients who were not readmitted were significantly better in experimental subjects than in control subjects. Stratified analysis showed that family intervention and regular use of medication had independent and additive effects on the outcome. During the 18 months after the index discharge patients who did not take medication regularly and who did not receive family intervention were 7.9 times as likely to be readmitted to hospital as patients who took medication regularly and received family intervention.

Reductive methylation and pKa determination of the lysine side chains in calbindin D9k

The Lys residues in the 75-residue Ca(2+)-binding protein calbindin D9k were reductively methylated with 13C-enriched formaldehyde. The possible structural effects resulting from the chemical modification were critically investigated by comparing two-dimensional NMR spectra and the exchange rates of some of the amide protons of the native and the modified protein. Our results show that the protein retains its structure even though 10 Lys out of a total of 75 amino acid residues were modified. In the Ca(2+)- and apo-forms of the protein, the 13C-methylated Lys residues can be detected with high sensitivity and resolution using two-dimensional (1H, 13C)-heteronuclear multiple quantum coherence (HMQC) NMR spectroscopy. The pKa values of the individual Lys residues in Ca(2+)-calbindin D9k and apo-calbindin D9k were obtained by combining pH titration experiments and (1H, 13C)-HMQC NMR spectroscopy. Each Lys residue in the Ca(2+)- and apo-forms of calbindin D9k has a unique pKa value. The Lys pKa values in the calcium protein range from 9.3 to 10.9, while those in the apo-protein vary between 9.7 and 10.7. Although apo-calbindin D9k has a very similar structure compared to Ca(2+)-calbindin D9k, the removal of two Ca2+ ions from the protein leads to an increase of the pKa values of the Lys residues.

The optimization of preparations of competent cells for transformation of E. coli

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Modulation of connexins during differentiation of oval cells into hepatocytes

The connexins are a family of related gap-junction proteins, implicated in embryonic development, cell growth control, and cellular differentiation. To identify connexins involved in liver cell differentiation, both in vivo and in vitro systems were employed to study expression of connexins 26, 32, and 43. Northern blot analysis and in situ hybridization were used to measure the levels of connexin expression and cellular localization of the transcripts, respectively. Normal liver expressed high connexin 32, low connexin 26, and barely detectable connexin 43. In vivo proliferation and differentiation of oval cells was at first accompanied by increased connexin 43 and decreased connexin 32 expression; later as the oval cells differentiated into hepatocytes, connexin 43 disappeared and connexin 32 increased to control levels. In situ hybridization showed that both oval cells and bile duct epithelial cells, but not hepatocytes, expressed connexin 43. A switch from connexin 43 to connexin 32 expression was observed following in vitro transformation and differentiation of rat liver epithelial cells toward the hepatocytic lineage. These results suggest that early progenitor cells in the liver express connexin 43 and a switch from connexin 43 to connexin 32 may signal commitment to hepatocytic differentiation.

Study on polyamide microcapsules containing oily liquids

Oily liquids were microencapsulated within polyphthalamide membranes with dodecyl sulphonate sodium (DSS) as an emulsifier. The mean diameter and the distribution, as well as the zeta-potential, of the microcapsules were analysed. It was found that the mean diameter decreases with an increase in stirring speed and emulsifier concentration during the emulsification step. The addition of DSS to aqueous phase resulted in a decrease in zeta-potential of the microcapsules.

Two-dimensional NMR studies of selenomethionyl calmodulin

Calmodulin (CaM) is a ubiquitous calcium regulatory protein that can interact with almost 30 different target proteins. The majority of the CaM-binding domains of the target proteins are believed to interact with two hydrophobic surfaces on Ca(2+)-CaM; these two regions are very rich in Met residues. To obtain more information about the role of these residues, we have biosynthetically incorporated selenomethionine (SeMet) in place of the nine Met residues of CaM. Amino acid analysis shows that the SeMet-CaM contains 15% Met and 85% SeMet. SeMet-CaM retains many of the properties of the wild-type protein; it activates the enzyme cyclic nucleotide phosphodiesterase, it binds to phenyl-Sepharose and myosin light chain kinase (MLCK) in a calcium-dependent manner, and it experiences a calcium-dependent band shift during SDS-gel electrophoresis. Moreover, by comparing the natural abundance (1H,13C)-heteronuclear multiple quantum coherence (HMQC) spectra of the calcium, apo and target peptide-bound forms of wild-type CaM and SeMet-CaM, we have found that the two proteins have very similar, if not identical, structures. Thus, the substitution of SeMet for Met does not cause a change in the conformation and function of CaM, in agreement with the results obtained for other proteins. The apo, calcium and target peptide-bound forms of SeMet-CaM were subsequently studied by natural abundance (1H,77Se)-heteronuclear multiple bond correlation (HMBC) and (1H,13C)-HMQC NMR. Nine well-resolved 77Se resonances could be observed. Substitution of SeMet for Met gave rise to the same 1H and 13C chemical shift changes for each individual Met residue, this facilitated making the assignments from known 1H,13C assignments of the Met residues. Some of these assignments were confirmed by studying Met-->Leu mutants of CaM. With the exception of Met76, which always remains solvent exposed, all resonances experienced large 77Se chemical shift changes upon the addition of Ca2+ and the MLCK peptide. The large shift changes indicate that the electron distribution in the SeMet side-chain can be adjusted for the different states of CaM, suggesting that the polarizability of sulfur or selenium may be important for the proper functioning of CaM. This study also shows that the natural abundance (1H,77Se)-HMBC experiment provides a sensitive approach for the study of SeMet proteins.

The effect of Met-->Leu mutations on calmodulin's ability to activate cyclic nucleotide phosphodiesterase

Calmodulin (CaM) has two hydrophobic surface patches that are particularly rich in Met residues, and these are the major contact areas where CaM interacts with its target enzymes. The amino acid Leu has been introduced by site-directed mutagenesis to replace all the Met residues in CaM. All nine individual Met-->Leu mutants of CaM as well as some double and quadruple mutants were expressed in Escherichia coli. All mutants could be purified by calcium-dependent hydrophobic affinity chromatography, indicating that they still expose their hydrophobic surfaces upon binding calcium. Each single Met-->Leu mutation in the C-terminal domain of the protein had little effect on its ability to activate phosphodiesterase (PDE), while a quadruple mutant with four C-terminal Leu residues instead of Met has a significantly lower affinity for PDE. The M36L mutant is a poor activator compared with the other three N-terminal single Met-->Leu mutants, which have a slightly lower affinity for PDE than wild-type CaM. The introduction of a positively charged Arg for Met-145 resulted in an almost complete loss of CaM's ability to activate PDE. Nuclear magnetic resonance spectroscopy was used to show that most CaM mutants retain their overall three-dimensional structure. Thus, the altered activation properties appear to arise from differences in the flexibility and polarizability of the Met and Leu sidechains, rather than from structural perturbations.

Overexpression and characterization of recombinant human fusion protein IL-6/IL-2 (CH925)

An expression vector encoding the human recombinant fusion protein interleukin 6/interleukin 2 (IL-6/IL-2) was constructed. When a flexible linker had been synthesized and ligated with the IL-2 gene fragment by polymerase chain reaction (PCR) amplification, the IL-6 gene fragment was unidirectionally inserted into the upstream of the linker-IL-2 sequence. The molecule of the IL-6-linker-IL-2 fusion gene named E. coli DH5 alpha/pfIL-6/2 was cloned and identified by DNA sequencing. The expressed protein named as CH925 showed a strong band on SDS-PAGE and amounted to 32% of total cell protein, and its estimated molecular weight was about 37 kDa. The fusion protein purified by gel filtration and reversed-phase HPLC showed as almost homogeneous. CH925 possesses both IL-2 and IL-6 activities when assayed by CTLL2- and 7TD1-dependent cell lines, respectively. The specific activity of IL-2 was 2.1 x 10(6) U/mg while that of IL-6 was 2.3 x 10(8) U/mg. Our studies exhibited that CH925 exerted a significant augmentative effect on the growth of erythroid colony forming units (CFU-E), and synergized with erythropoietin (EPO) and/or IL-3 in a dose-dependent way. Our experimental results also showed CH925 at a low dose causing active lymphokine-activated killer (LAK) cell proliferation more vigorous than IL-2 and/or IL-6 (p < 0.001). CH925 is a novel fusion protein, being neither IL-6 nor IL-2, more potent than IL-2 and/or IL-6 and causing non-IL-2 and non-IL-6 functions of strong EPO-like and mild IL-3-like effects on erythroid progenitor cell growth. There is a potential for efficacious clinical application of CH925.

Crystallization and preliminary X-ray analysis of the low molecular weight phosphotyrosyl protein phosphatase from bovine heart

Two crystal forms of bovine heart phosphotyrosyl protein phosphatase (BHPTP) have been examined by X-ray analysis. One crystal form grows as long rods with triclinic crystal symmetry and diffracts to 3 A resolution. The diffraction pattern of this form of the crystal shows twinning about a major axis. A second crystal form of BHPTP grows as flat trapezoidal prisms with monoclinic symmetry C2, and unit cell parameters a = 95.3 A, b = 43.3 A, c = 41.2 A and beta = 113.5 degrees. The unit cell dimensions indicate that there is one 18 kDa molecule per asymmetric unit. These crystals diffract to at least 2.2 A resolution and are resistant to decay in the X-ray beam.

Interleukin 12 at the site of disease in tuberculosis

Interleukin 12 (IL-12), a heterodimeric cytokine composed of p40 and p35 chains, has potent immunologic effects in vitro. We used tuberculous pleuritis as a model to study the immunoregulatory potential of IL-12 in vivo at the site of human infectious disease. Messenger RNAs for p40 and p35 were detected in pleural fluid from six of six patients by reverse-transcription polymerase chain reaction. By using an ELISA that detected both free p40 and heterodimeric IL-12, we found that mean concentrations were 585 +/- 89 pg/ml in pleural fluid of patients with tuberculous pleuritis, which were significantly higher than those in serum of the same patients (54 +/- 36 pg/ml), or in malignant pleural effusions (123 +/- 35 pg/ml). By using an ELISA specific for heterodimeric IL-12, we found that mean concentrations in pleural fluid of patients with tuberculous pleuritis were 165 +/- 28 pg/ml and undetectable in serum of the same patients, or in malignant pleural effusions. Bioactive IL-12 was detectable in five of five supernatants of pleural fluid cells stimulated with Mycobacterium tuberculosis. Addition of anti-IL-12 antibodies suppressed proliferative responses of pleural fluid cells to M. tuberculosis by 36 +/- 7%. These data indicate that IL-12 may play a role in the human immune response to infectious agents in vivo. We hypothesize that IL-12 contributes to the antimycobacterial immune response by enhancing production of interferon-gamma, facilitating development of Th1 cells and augmenting cytotoxicity of antigen-specific T cells and natural killer cells.

[The relationship between thymus involution and diseases in childhood]

70 thymuses obtained at autopsy from children who died of various diseases were studied with histological, immunohistochemical and ultrastructural methods. In the immunohistochemical study, antibodies against 8 lymphocyte differentiation antigens, including CD4, CD8, CD3, CD1, CD2, CD25, CD22 and T9 as well as those against keration and S-100 protein were used. The findings suggest that thymus involution can occur in different diseases. The differentiation process of thymocytes and the distribution of different sub-populations of T cells in the thymus are not changed by thymus involution. Among the major changes of thymus involution, the decrease in number of dendritic cells and the degeneration of epithelial cells are more important than the decrease in the number of thymocytes. Phagocytosis of macrophages seems to be the secondary way to dispose of the degenerated and dead thymocytes.

Distribution of NADPH-diaphorase-positive neurons in the enteric nervous system of the human colon

Recent investigations have demonstrated the colonization of NOS-immunoreactivity and NADPH-diaphorase staining in central and peripheral neurons. The current study investigates the presence and distribution of NADPH-diaphorase-stained nerve cells and fibres in whole-mount preparations of the enteric nervous system of the human colon. Numerous NADPH-diaphorase-stained nerve cell bodies were found in the plexus myentericus and in the plexus submucosus externus. In contrast, we found but very few NADPH-diaphorase-stained nerve cells in the plexus submucosus internus. The majority of the NADPH-diaphorase-stained nerve cells had morphological characteristics similar to those of the Dogiel type I neuron, i.e. possessing broad flat dendrites and one major axonal projection. NADPH-diaphorase-stained nerve fibres can be observed in all three ganglionic networks and in the aganglionic plexus of the circular muscle layer.

Beneficial effect of an ACTH-(4-9) analog (Org2766) in the treatment of experimental cortex lesion in rats

This paper reports that lesions of the medial frontal cortex (MFC) caused behavioral deficit in rats and that this deficit could be attenuated by a well formulated treatment with Org2766, an analog of ACTH-(4-9). Wistar rats were distributed in 3 groups: MFC lesion treated with saline (M-N); MFC lesion treated with Org2766 (M-O); and sham-operation treated with saline (S). Repeated Org2766 or saline injection commenced from the day of surgery and lasted for 13 days. After surgery, the rats were trained in a passive avoidance task and then in an active avoidance task. MFC lesions were found to be strongly associated with behavioral deficits. The M-N group rats displayed poor retention of the passive avoidance response and showed much slower learning of the active avoidance task as compared to S group rats. The result showed that chronic Org2766 administration improved the behavioral performance of both tasks in MFC lesioned rats. The also revealed that the superoxide dismutase (SOD) activity was significantly increased in the M-O group as compared to the M-N group 15 days after surgery. The possible mechanisms related to the beneficial effect of Org2766 on cortex damage are discussed.