Biological monitoring of workers exposed to dimethylformamide in a textile polyurethane unit

Dimethylformamide (DMF) is a universal solvent noted for its solubility in both aqueous and lipid media. It is hepatotoxic, and there are concerns about its carcinogenicity. Our objective was to determine the correlation between air monitoring measurements and biological measurements of a suitable metabolite of DMF in a cohort of operatives in a polyurethane production unit. This was done with a view to assessing how much the inhalation route contributed to total DMF exposure, mainly for control purposes. We investigated the relationship between personal air sample measurements of DMF and biological measurements of N-methylformamide (NMF) in nine adult subjects, recruited across the shifts, with varying levels of exposure to DMF. Personal exposure monitoring was carried out with a low-flow-rate Model 222-4 SKC pump, while post-shift urine samples were obtained for further analysis. Operatives were asked to abstain from consuming alcohol for 24 h before the designated shift, as advised by the laboratory responsible for the analysis of urine samples. We found a very strong statistical association between air sample measurements of DMF and NMF in the urine of the sample population (R(2) = 0.95, P < 0.0001). This study suggests that airborne exposure contributes significantly to elevated levels of NMF and, therefore, indicates that efforts should be concentrated on engineering controls in reducing workplace DMF exposure.

Essential role of Drosophila Hdac1 in homeotic gene silencing

Deacetylation of the N-terminal tails of core histones plays a crucial role in gene silencing. Rpd3 and Hda1 represent two major types of genes encoding trichostatin A-sensitive histone deacetylases. Although they have been widely found, their cellular and developmental roles remain to be elucidated in metazoa. We show that Drosophila Hdac1, an Rpd3-type gene, interacts cooperatively with Polycomb group repressors in silencing the homeotic genes that are essential for axial patterning of body segments. The biochemical copurification and cytological colocalization of HDAC1 and Polycomb group repressors strongly suggest that HDAC1 is a component of the silencing complex for chromatin modification on specific regulatory regions of homeotic genes.

GC-FID as a primary method for establishing the purity of organic CRMs used for drugs in sport analysis

The National Analytical Reference Laboratory has synthesized and characterized 67 anabolic steroid marker metabolites, both unlabelled and deuterated, and 37 key glucuronide and sulfate steroid conjugate pure substance reference materials. Work is also in process to establish their full traceability so that they can be issued as certified and primary reference materials. Both identity and purity have been rigorously characterized using a number of techniques and a primary method for purity assessment developed, based gas chromatography combined with flame ionization detection for the parent steroids and HPLC with evaporative light scattering detection for non-volatile steroid conjugates. Strategies for establishing traceability and for estimating measurement uncertainty are reported. The strategies described are considered applicable to a wide range of organic pure substance reference materials.

Purification and characterization of recombinant human lysosomal alpha-mannosidase

Lysosomal alpha-mannosidase (EC 3.2.1.24) is required in the degradation of the asparagine-linked carbohydrates of glycoproteins. Deficiency of this enzyme leads to the lysosomal storage disorder alpha-mannosidosis. As an initial step toward enzyme replacement therapy for alpha-mannosidosis, the human lysosomal alpha-mannosidase cDNA was cloned into the pcDNA 3.1 vector and expressed in Chinese hamster ovary cells. Dimethyl sulfoxide (DMSO) added to the cell culture media to induce growth arrest led to a 4-fold increase in the enzyme production, with an average yield of 3.2 mg L(-1) day(-1). alpha-Mannosidase was secreted as an active homodimer of a 130-kDa precursor that was proteolyzed into two polypeptides of 55 and 72 kDa during the subsequent purification of the enzyme. N-terminal sequence analysis of the purified enzyme revealed that the proteolysis occurred close to a cleavage site previously identified in the intracellular form of lysosomal alpha-mannosidase. Generation of monoclonal antibodies against the recombinant enzyme made it possible to develop a single-step immunoaffinity purification procedure for alpha-mannosidase. The immunoaffinity-purified enzyme which mainly consisted of the 130-kDa precursor, displayed specific activity and kinetics similar to those of the processed form. Recombinant alpha-mannosidase was taken up by cultured alpha-mannosidosis fibroblasts and was trafficked to the lysosomes via the mannose 6-phosphate pathway where it reduced the amounts of stored mannose-containing oligosaccharides.

Functional annotation of a full-length mouse cDNA collection

The RIKEN Mouse Gene Encyclopaedia Project, a systematic approach to determining the full coding potential of the mouse genome, involves collection and sequencing of full-length complementary DNAs and physical mapping of the corresponding genes to the mouse genome. We organized an international functional annotation meeting (FANTOM) to annotate the first 21,076 cDNAs to be analysed in this project. Here we describe the first RIKEN clone collection, which is one of the largest described for any organism. Analysis of these cDNAs extends known gene families and identifies new ones.

Caprine mucopolysaccharidosis IIID: a preliminary trial of enzyme replacement therapy

Mucopolysaccharidosis type IIID (MPS IIID) is a lysosomal storage disorder resulting from lack of activity of the lysosomal hydrolase N-acetylglucosamine 6-sulfatase (6S) (EC 3.1.6.14). The syndrome is associated with systemic and central nervous system (CNS) heparan sulfate glycosaminoglycan (HS-GAG) accumulation, secondary storage of lipids, and severe, progressive dementia. In this investigation, caprine MPS IIID, established as a large animal model for the human disease, was used to evaluate the efficacy of enzyme replacement therapy (ERT). Recombinant caprine 6S (rc6S) (1 mg/kg/dose) was administered intravenously to one MPS IIID goat kid at 2, 3, and 4 wks of age. Five days after the last dose, the uronic acid (UA) content and the composition of uncatabolized HS-GAG fractions in the brain of the ERT-treated MPS IIID kid were similar to those from a control, untreated MPS IIID animal. However, hepatic uronic acid levels in the treated MPS IIID kid were approximately 90% lower than those in the untreated MPS IIID control; whereas the composition of the residual hepatic HS-GAG was identical to that in the untreated animal. Marked reduction of lysosomal storage vacuoles in hepatic cells of the treated MPS IIID kid was observed, but ERT had no effect on CNS lesions. No residual 6S activity was detected in brain or liver. This preliminary investigation indicates that other treatment regimens will be necessary to ameliorate MPS III-related CNS lesions.

Localization of concealed norplant implants and implant fragments by a modified mammography technique

A modified mammography technique for localization of concealed Norplant implants and Norplant fragments was applied to four patients, ages 18, 35, 22, and 25. A dedicated mammography unit and mammography film screen system affording high resolution and high contrast was applied under the same conditions to each patient. 26 kilovoltage peak (KVp) was used, ranging from 60 to 150 milliamperes. Using both the automatic exposure control and manual techniques, specific milliampere range depended on the specific case. The technique proved successful, as concealed Norplant capsules were exquisitely visualized by films obtained with a Siemens Mammomat 3000. Applying the same modified technique, precise location of the Norplant implants was determined using a fenestrated compression plate with an alphanumeric grid in a manner similar to hookwire localization of breast lesions under mammographic guidance. The capsules were then safely retrieved. We conclude that this modified technique may provide practitioners with valuable assistance in the exact localization of the Norplant capsule(s) or fragments, thereby facilitating their removal. Application of a modified mammography technique reveals precise localization of concealed Norplant capsules facilitating their removal.

An orally active anti-apoptotic molecule (CGP 3466B) preserves mitochondria and enhances survival in an animal model of motoneuron disease

Apoptosis and mitochondrial dysfunction are thought to be involved in the aetiology of neurodegenerative diseases. We have tested an orally active anti-apoptotic molecule (CGP 3466B) that binds to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in an animal model with motoneuron degeneration, i.e. a mouse mutant with progressive motor neuronopathy (pmn). In pmn/pmn mice, CGP 3466B was administered orally (10 - 100 nmol kg(-1)) at the onset of the clinical symptoms (2 weeks after birth). CGP 3466B slowed disease progression as determined by a 57% increase in life-span, preservation of body weight and motor performance. This improvement was accompanied by a decreased loss of motoneurons and motoneuron fibres as well as an increase in retrograde transport. Electron microscopic analysis showed that CGP 3466B protects mitochondria which appear to be selectively disrupted in the motoneurons of pmn/pmn mice. The data support evaluation of CGP 3466B as a potential treatment for motor neuron disease.

Soluble TNF receptors partially protect injured motoneurons in the postnatal CNS

There is accumulating evidence that cytokines are involved in the functioning of the brain and the spinal cord. However, it has been controversial whether they exert a neurotoxic or a neuroprotective effect. To address this question in vivo, we have examined the survival of injured motoneurons in a line of transgenic mice that overexpress the soluble form of tumour necrosis factor receptor-1 (sTNFR1). In these animals, all of the circulating TNF and lymphotoxin-alpha are neutralized by the continuous expression of the soluble receptor. Following axotomy of the facial nerve in 7-day-old control mice, we observed a loss of approximately 90% of the motoneurons at two weeks survival. In the transgenic mice under the same conditions, the percentage of motoneuron survival was increased two-fold (515 vs. 224) and varied as a function of the level of the circulating receptor. These results indicate that neutralization of endogenous TNF and lymphotoxin-alpha by means of overexpression of the soluble receptor can decrease cell death of injured motoneurons and suggest that these cytokines may play an important role in neuronal degeneration in the CNS following a lesion.

Beryllium, an adjuvant that promotes gamma interferon production

Beryllium is associated with a human pulmonary granulomatosis characterized by an accumulation of CD4(+) T cells in the lungs and a heightened specific lymphocyte proliferative response to beryllium (Be) with gamma interferon (IFN-gamma) release (i.e., a T helper 1 [Th1] response). While an animal model of Be sensitization is not currently available, Be has exhibited adjuvant effects in animals. The effects of Be on BALB/c mice immunized with soluble leishmanial antigens (SLA) were investigated to determine if Be had adjuvant activity for IFN-gamma production, an indicator of the Th1 response. In this strain of Leishmania-susceptible BALB/c mice, a Th2 response is normally observed after in vivo SLA sensitization and in vitro restimulation with SLA. If interleukin-12 (IL-12) is given during in vivo sensitization with SLA, markedly increased IFN-gamma production and decreased IL-4 production are detected. We show here that when beryllium sulfate (BeSO(4)) was added during in vivo sensitization of BALB/c mice with SLA and IL-12, significantly increased IFN-gamma production and decreased IL-4 production from lymph node and spleen cells were detected upon in vitro SLA restimulation. No specific responses were observed to Be alone. Lymph node and spleen cells from all mice proliferated strongly and comparably upon in vitro restimulation with SLA and with SLA plus Be; no differences were noted among groups of mice that received different immunization regimens. In vivo, when Be was added to SLA and IL-12 for sensitization of BALB/c mice, more effective control of Leishmania infection was achieved. This finding has implications for understanding not only the development of granulomatous reactions but also the potential for developing Be as a vaccine adjuvant.

NGF-induced motoneuron cell death depends on the genetic background and motoneuron sub-type

Nerve growth factor (NGF) promotes the survival of several neuronal populations, but recently it has also been shown to induce neuronal cell death. Here we report the effects of NGF on lesioned motoneurons. We have analyzed facial and sciatic motoneurons in newborn and adult BALB/c and C57BL/6 mice, in addition to mice deficient in the low-affinity p75 receptor for the neurotrophins (p75NTR). NGF application did not alter survival of lesioned facial motoneurons in any of the strains examined independent of the age of the animals. Only in the adult C57BL/6 mouse strain where the sciatic nerve had been crushed prior to factor application did NGF induce cell death of axotomized sciatic motoneurons. Our results illustrate the importance of the genetic background and the motoneuron sub-type in studies related to cell death and survival of motoneurons in relation to NGF and p75NTR.

Telephone therapy for patients with breast cancer

PURPOSE/OBJECTIVES

To test the value of telephone-administered cognitive-behavioral therapy in a study of patients with breast cancer.

DESIGN

Women were assigned randomly to a therapy group or an assessment-only control group.

SETTING

A tertiary cancer treatment center serving rural areas of North Dakota and Minnesota.

SAMPLE

Women were recruited within three to four months of stage I (n = 27) or stage II (n = 26) breast cancer diagnosis. Age ranged from 30-82 (mean = 51.5 years). Most participants (n = 35) underwent a modified radical mastectomy; 17 underwent a lumpectomy.

METHODS

Therapy involved 10 30-minute (or less) telephone sessions. Data that were collected from mailed questionnaires included psychological distress (Profile of Mood States), perceived stress, coping (Coping Response Indices-Revised), quality of life (Medical Outcome Scale), and satisfaction with therapy. Measures were completed at baseline and at 4- and 10-month follow-up intervals.

MAIN RESEARCH VARIABLES

Telephone therapy, stress, coping, and quality of life.

FINDINGS

With time, women in the therapy and control groups reported reduced stress and improved quality of life. However, significant reductions in some kinds of distress (anxiety, anger, depression, and confusion) were not observed. Most therapy participants liked the telephone treatment sessions but showed only modest improvement (less anxiety and confusion) compared with women in the control group.

CONCLUSIONS

Most patients reported being comfortable with the telephone therapy and said that they felt better as a result of it. However, the outcome data showed that telephone therapy--as carried out in this study--produced only modest benefits. Researchers need to consider who is best for delivering such therapy.

IMPLICATIONS FOR NURSING PRACTICE

Providing telephone therapy to patients with breast cancer has potential benefits, and nurses may be the appropriate professionals to administer the therapy.

Glucocorticoid stimulation of corticotropin-releasing hormone gene expression requires a cyclic adenosine 3',5'-monophosphate regulatory element in human primary placental cytotrophoblast cells

Production of placental CRH, which is identical to the peptide synthesized and secreted in the hypothalamus, has been linked to human parturition. Glucocorticoids stimulate placental CRH secretion and messenger ribonucleic acid expression, in contrast to their inhibition of CRH synthesis in the hypothalamus. A positive feedforward loop involving glucocorticoid-CRH-ACTH-glucocorticoid is thought to drive the exponential increase in placental CRH leading to delivery. Tissue-specific effects of glucocorticoids on CRH expression are therefore of interest. Using human primary placental cells, we investigated the mechanism by which glucocorticoids stimulate placental CRH gene expression. Nuclear run-on transcription shows that in human placental cells glucocorticoids up-regulate transcription of human CRH (hCRH). Using transient transfection assays we demonstrate that dexamethasone up-regulates both basal and cAMP-stimulated hCRH promoter activity, correlating well with the increase in endogenous CRH peptide levels. Through mutagenesis and deletion analyses we show that dexamethasone stimulation of hCRH gene transcription requires a functional cAMP regulatory element (CRE); this CRE is adequate to confer dexamethasone stimulation upon a heterologous promoter, and electrophoretic mobility shift assay studies show that a placental nuclear protein specifically binds to the hCRH CRE.

Corticotropin-releasing hormone gene expression in primary placental cells is modulated by cyclic adenosine 3',5'-monophosphate

CRH, the principal neuropeptide regulator of pituitary ACTH secretion, is also expressed in placenta. Placental CRH has been linked to the process of human parturition. However, the mechanisms regulating transcription of the CRH gene in placenta remain unclear. cAMP signaling pathways play important roles in regulating the expression of a diverse range of endocrine genes in the placenta. Therefore, we have explored the effect of cAMP on CRH promoter activity in primary cultures of human placental cells. Both forskolin and 8-bromo-cAMP, activators of protein kinase A, can increase CRH promoter activity 5-fold in transiently transfected human primary placental cells, in a manner that parallels the increase in endogenous CRH peptide. Maximal stimulation of CRH promoter activity occurs at 500 micromol/L 8-bromo-cAMP and 10 micromol/L forskolin. Electrophoretic mobility shift assay and mutation analysis combined with transient transfection demonstrate that in placental cells cAMP stimulates CRH gene expression through a cAMP regulatory element in the proximal CRH promoter region and involves a placental nuclear protein interacting specifically with the cAMP regulatory element.

Gonadal steroids regulate the number and activational state of mast cells in the medial habenula

While mast cells in connective tissues have long been associated with allergic reactions, it is now clear that they are also present within the central nervous system under normal physiological conditions. The mast cell population increases 10-fold in the medial habenular region of the brain within 2 h after pairing in doves. The first study explored whether this increase was due to exposure to gonadal steroids. Light microscopic immunocytochemistry indicates an increased number of brain MC following exposure to either testosterone (T) or dihydrotestosterone (DHT) in the male, or 17beta estradiol (E) in the female, but not in cholesterol-treated controls. Thus, the increased habenular MC population is produced by gonadal hormones in the absence of sexual behavior, is not sexually dimorphic, and does not require aromatization of androgen. In the next study, MC activational state was determined using electron microscopy. Cells were categorized into five states: (I) resting; (II) initiation of degranulation; (III) fully degranulated; (IV) piecemeal secretion; and (V) resynthesizing. Hormone treatment (T, DHT, or E) resulted in a significant increase in the percent of cells in activated states. MC granules contain a wide range of biologically active molecules. The release of these granule contents into the neuropil of the central nervous system is likely to have wide ranging effects at multiple levels including vascular permeability and neuronal excitability. In that steroid treatment is known to result in such effects, the present demonstration of a hormonally induced shift in MC secretory state is one avenue by which these effects are mediated.

A soiling system for evaluation of house dust, allergens, and lead retention on carpets and other surfaces

Artificial soiling of carpeted or other floor surfaces has several important applications in human exposure assessment and textile research including evaluation of textile properties, sampling devices, and cleaning regimens. A method was developed and validated to deposit uniform and reproducible known quantities of house dust, allergens, and leaded dust on carpets. The soiling apparatus consisted of a 100 cm x 60 cm inclined steel track and a plastic cylinder, with a series of staggered holes, that contains a known volume of reference house dust. After deposition, the dust is embedded by dragging a steel rod over the carpet surface. Deposition tests were performed with bulk house dust, sodium chloride, and house dust with reference quantities of dust mite allergen and lead. The apparatus deposited equivalent (arithmetic mean) amounts of dust, sodium chloride, and dust mite allergen on the front and back halves of test carpets. The introduction of inert fumed silica to the reference sample aided in dispersal of dust over test surfaces. Little to no variation in mean deposition was found within or between 4 days of testing. Using a grid containing weighing boats under the apparatus, spatial deposition was found to vary across a 92 x 46 cm surface by 13 percent. The apparatus deposited reproducible mean quantities of bulk dust on test surfaces from 7 g/m2 to 28 g/m2 with a coefficient of variation ranging from 4-6 percent. The apparatus could be altered to deliver smaller or larger amounts of dust.

Treatment costs of directly observed therapy and traditional therapy for Mycobacterium tuberculosis: a comparative analysis

OBJECTIVE

Treatment of tuberculosis is a time-consuming and expensive process, often complicated by patient non-adherence. Directly observed therapy (DOT), an out-patient management strategy designed to ensure adherence, is not widely used because it is perceived to be too expensive. This study compared costs of tuberculosis treatment in DOT to the same factors in traditional therapy.

DESIGN

A retrospective economic evaluation of 659 tuberculosis cases was reported to a major metropolitan county public health department between 1980 and 1994. Out-patient costs, in-patient costs and the cost impact of relapse and acquired resistance were estimated in 1995 dollars.

RESULTS

Treatment costs were lower with DOT: $15,670 per case for in-patient care and $700 per case for out-patient care (P < 0.001). These cost differences resulted from shorter therapy duration (334 vs 550 days), fewer patient hospitalizations (58 vs 75%) and shorter hospital stays (26 vs 55 days per hospitalized patient). Relapse or acquired resistance occurred in 10.9% of patients and accounted for 35.7% of cost with traditional therapy, as compared to 1.2% of patients and 6.0% of cost with observed therapy.

CONCLUSIONS

Directly observed therapy is less costly than traditional therapy.