Antibody response to Cryptococcus neoformans proteins in rodents and humans

The prevalence and specificity of serum antibodies to Cryptococcus neoformans proteins was studied in mice and rats with experimental infection, in individuals with or without a history of potential laboratory exposure to C. neoformans, human immunodeficiency virus (HIV)-positive individuals who developed cryptococcosis, in matched samples from HIV-positive individuals who did not develop cryptococcosis, and in HIV-negative individuals. Rodents had little or no serum antibody reactive with C. neoformans proteins prior to infection. The intensity and specificity of the rodent antibody response were dependent on the species, the mouse strain, and the viability of the inoculum. All humans had serum antibodies reactive with C. neoformans proteins regardless of the potential exposure, the HIV infection status, or the subsequent development of cryptococcosis. Our results indicate (i) a high prevalence of antibodies reactive with C. neoformans proteins in the sera of rodents after cryptococcal infection and in humans with or without HIV infection; (ii) qualitative and quantitative differences in the antibody profiles of HIV-positive individuals; and (iii) similarities and differences between humans, mice, and rats with respect to the specificity of the antibodies reactive with C. neoformans proteins. The results are consistent with the view that C. neoformans infections are common in human populations, and the results have implications for the development of vaccination strategies against cryptococcosis.

Intraarticular triamcinolone hexacetonide injection in children with chronic arthritis: a survey of clinical practice

To assess the efficacy of the intraarticular steroid(IAS) injection in the management of arthritis and the possible related complications in children with chronic arthritis. We evaluated 11 children of chronic arthritis (4 girls and 7 boys), age of onset ranged from 2-13.6 years, who had persistent arthritis treated with IAS from November 1994 to June 1997. The results of injections showed that the beneficial effect was noted within one day to 2 weeks without significant adverse reactions, remission exceeding 6 months was seen in 10 of 11 patients (in 14 of 18 joints). According to subgroups of chronic arthritis, the remission rate of IAS injection in children with pauciarticular arthritis reached 100%. A significant fall in C-reactive protein (CRP) between pre- and post-IAS injection (p = 0.03), but there were no differences in hemoglobin (Hb), white blood cells (WBCs), thrombocytes (Plts), erythrocyte sedimentation rate (ESR) and osteocalcin level. No injection-related complications were found. In conclusion, the IAS injection was an effective and safe treatment in children with chronic arthritis with no obvious complications especially in pauciarticular arthritis.

Labeling of proteins with [35S]methionine and/or [35S]cysteine in the absence of cells

Incubation of [35S]methionine and [35S]cysteine with bovine albumin, globulin, catalase, hemoglobin, or human globulin resulted in incorporation of the 35S label into each of these proteins. Trichloroacetic acid (TCA) precipitation revealed that the percentage of label incorporated ranged from 1 to 15%. The 35S labeling was resistant to dissociation by reducing SDS-PAGE, prolonged dialysis against 4 M urea, heating, TCA precipitation, and dilution by gel filtration. The labeling effect was more efficient with [35S]cysteine than [35S]methionine. Incubation of 35S label with proteins differing in methionine and cysteine content revealed no requirement for sulfur-containing amino acids in the target protein. Protein carboxymethylation reduced but did not prevent 35S label incorporation. Amino acid analysis of labeled proteins revealed that the radioactive label was not consistently associated with an individual amino acid. Differences in the ability of various proteins to spontaneously label with these amino acids suggest caution in the interpretation of metabolic labeling experiments and the necessity for inclusion of additional controls. Alternatively, our experience indicates a potentially useful method for labeling proteins in the absence of cells.

[Coding theories and analyzing methods of information contained in neuronal spike trains]

Information transmission in the central nervous system relies on neurons working in relays. At chemical synapses information transmission is by means of neurotransmitters, whereas long-distance transmission is carried out by action potentials conducting along nerve fibers. Hence how to pick up and analyze information contained in the spike trains are important topics of several branches of sciences such as neuroscience, bioinformatics, etc. So far there is lack of ideal ways and means. This review briefly introduces the advantages and limitations of the principal coding theories and analyzing methods of information contained in spike trains, and the progress in this field.

Diagnosis of anomalous innominate artery syndrome by spiral CT with 3D reconstruction of the airway: report of one case

Stridor in infants is a symptom that indicates partial obstruction of the large airways. Vascular rings are an unusual cause of tracheal compression which can induce stridor in infants and children. We report a 4-month-old boy with recurrent wheezing and stridor for 2 months. Spiral computed tomography (CT) and three-dimensional (3D) reconstruction aided in the diagnosis of external compression on the trachea by an innominate artery. Successful relief of the airway's obstruction was achieved by aortopexy. Three months after surgery, he was symptom free without any medication.

Variants of a Cryptococcus neoformans strain elicit different inflammatory responses in mice

The virulence of Cryptococcus neoformans isolates with high and low extracellular proteolytic activity was investigated in mice. No consistent relationship between proteolytic activity and virulence was observed, but isolates derived from one strain were shown to elicit different inflammatory responses.

A centrifugal particle concentrator for use in inhalation toxicology

Epidemiologic studies have provided strong evidence that episodic exposure to ambient particulate matter is associated with increases in morbidity and mortality. These adverse effects have been demonstrated at concentrations far below the National Ambient Air Quality Standard (NAAQS), and thus, the biological plausibility of these effects has been questioned. For the purpose of exposing test animals to relevant and reproducible exposure concentrations of ambient particulate matter (PM), we have developed a simple and inexpensive concentrator system that can concentrate ambient particles 10-fold. A high-volume blower is used to deliver ambient air to the inlet manifold of a centrifugal concentrator and the entrained particles travel along a concentric annulus formed by a stationary solid outer cylinder and a porous inner cylinder rotating at high speed (up to 12,500 rpm). Suction applied at one end of the porous shaft causes the dispersion medium (air) to pass through the porous cylinder and into the shaft. Since the rotational velocity of airborne particles is comparable to that of the rotating cylinder near its surface, the particles move radially outward due to the centrifugal force, in addition to their motion laterally along the cylinder and inward due to the suction of air into the rotating porous cylinder. The particles reach their highest concentration near the outlet manifold, where they enter the exposure chamber under positive pressure ( approximately 0.4 cm H2O). Except for coarse particle loss due to impaction and diffusional loss of ultrafine particles in the concentrator, the increase in particle concentration is the ratio of the flow rates for the inlet air and the air delivered to the exposure chamber. We have used the centrifugal concentrator to deliver concentrated ambient urban PM to a nose-only exposure chamber and examined the concentrating effect across ambient particle sizes.

Expression of metallothionein protein in the lungs of Wistar rats and C57 and DBA mice exposed to cadmium oxide fumes

Chronic exposure to inhaled cadmium (Cd) has been shown to induce lung tumors in rats (Wistar strain) but not in mice (NMRI strain). The protein metallothionein (MT) plays an important role in Cd detoxification, and it has been suggested that differential inducibility of pulmonary MT may lead to interspecies susceptibility differences to inhaled Cd. Interstrain differences in the pulmonary response of the MT gene to Cd stimuli have not been examined in rats or mice. We compared pulmonary MT expression in Wistar Furth (WF) rats with that in DBA and C57 mice, following a single 3-h exposure to CdO fumes containing 1 mg Cd/m3. Induction of the MT gene was assessed by the levels of MT-I and MT-II transcripts, MT-protein content, and number of MT-labeled alveolar and bronchiolar epithelial cells immediately after Cd exposure and 1, 3, and 5 days later. Control animals were exposed to air/argon furnace gases. We observed differential intra- and interspecies inducibility of the MT gene in the lung following Cd inhalation. DBA mice exhibited greater levels of MT-mRNA, mainly for the MT-I isoform, MT-protein content, and number of MT positive cells relative to C57 mice. WF rats showed lower transcription and translation responses of the MT gene upon Cd stimuli than C57 mice. The present results, in concert with our previous findings of higher lung cell proliferation in Cd-exposed C57 relative to DBA mice, predict greater susceptibility of C57 to the carcinogenic effects of inhaled Cd. Furthermore, the low transcriptional and translation responses of the MT gene to Cd stimuli in WF rats might explain the higher susceptibility of this rat strain to develop malignant lung tumors after chronic exposure to Cd via inhalation. Parallel to our findings in mice, differences in the responsiveness of lung MT gene may exist across rat strains. Thus intraspecies genetic variability in pulmonary MT may influence the susceptibility of rats or mice to lung carcinogenesis induced by inhalation of Cd compounds.

Sulphasalazine in the treatment of children with chronic arthritis

The aim of this study was to investigate the efficacy and toxicity of sulphasalazine (SASP) in the treatment of children with chronic arthritis. The medical records of 36 children (25 boys, 11 girls) who received SASP for the treatment of chronic arthritis were reviewed. Twenty-one patients had juvenile spondyloarthropathies (JSA) (eight juvenile ankylosing spondylitis (JAS), 13 undifferentiated JSA (uJSA) and 15 had juvenile rheumatoid arthritis (JRA). The patients received SASP therapy for a mean of 2.5 years (range 3 weeks to 8.1 years). Clinical and laboratory data were reviewed retrospectively to determine the effects of treatment. A clinically significant response occurred in 23 (64%) children: remission in 14 (39%) (JRA 5, JSA 9) and improvement (25% reduction in joint count) in nine (25%) (JRA 4, JSA 5). There was no difference in response rate between JRA and JSA patients (p = 0.11), but the time to remission was shorter in JSA patients (mean 5 months) than in JRA patients (mean 25 months) (p = 0.024). Twelve of the 36 patients discontinued non-steroidal anti-inflammatory drugs, and six of eight patients discontinued prednisolone. A significant fall in erythrocyte sedimentation rate and rise in haemoglobin occurred in SASP-treated patients (p < 0.005) comparing most recent results with pretreatment levels. Side-effects occurred in four of 36 patients (11%); only one patient who had persisting severe diarrhoea required discontinuation of SASP. It was concluded that SASP appears to be effective and safe in the treatment of JRA and JSA patients. As a second-line agent, SASP is the drug of first choice for patients with JSA; for JRA patients SASP may be a useful, possibly less toxic alternative to methotrexate.

Differential regulation of arginases and inducible nitric oxide synthase in murine macrophage cells

Activated macrophages avidly consume arginine via the action of inducible nitric oxide synthase (iNOS) and/or arginase. In contrast to our knowledge regarding macrophage iNOS expression, the stimuli and mechanisms that regulate expression of the cytosolic type I (arginase I) or mitochondrial type II (arginase II) isoforms of arginase in macrophages are poorly defined. We show that one or both arginase isoforms may be induced in the RAW 264.7 murine macrophage cell line and that arginase expression is regulated independently of iNOS expression. For example, 8-bromo-cAMP strongly induced both arginase I and II mRNAs but not iNOS. Whereas interferon-gamma induced iNOS but not arginase, 8-bromo-cAMP and interferon-gamma mutually antagonized induction of iNOS and arginase I mRNAs. Dexamethasone, which did not induce either arginase or iNOS, almost completely abolished induction of arginase I mRNA by 8-bromo-cAMP but enhanced induction of arginase II mRNA. Lipopolysaccharide (LPS) induced arginase II mRNA, but 8-bromo-cAMP plus LPS resulted in synergistic induction of both arginase I and II mRNAs. In all cases, increases in arginase mRNAs were sufficient to account for the increases in arginase activity. These complex patterns of expression suggest that the arginase isoforms may play distinct, although partially overlapping, functional roles in macrophage arginine metabolism.

Pemphigus vulgaris

Pemphigus vulgaris is an autoimmune vesiculobullous disease of the skin and the mucous membrane. It most commonly involves the population of the fifth and sixth decades, and is extremely rare in children. We report a case of this disease in a 13-year-old boy, who was documented to have pemphigus vulgaris with historical, histopathological, and immunological criterion. He received corticosteroid and immunosuppressive drugs and a good response was achieved. We concluded that pemphigus vulgaris is a rare disease in children, but it should be kept in mind as a differential diagnosis of oral ulceration along with skin manifestation in children.

Induction of interleukin-8 by ozone is mediated by tyrosine kinase and protein kinase A, but not by protein kinase C

Ozone is one of the most common air pollutants humans routinely inhale. We have previously shown that in vitro ozone exposure induces the DNA-binding activities of NF-kappaB and NF-IL6 as well as the expression of interleukin 8 in respiratory epithelial cells. In this study, we investigated intracellular signaling steps mediating ozone-induced inflammatory mediator release. A549 cells, a type II like alveolar epithelial cell line, were exposed in vitro to air or 0.1 ppm of ozone in the presence of several kinase inhibitors. Exposure to ozone increased interleukin 8 expression and transcription factor activities in a protein tyrosine kinase (PTK)-dependent and protein kinase A (PKA)-dependent, yet protein kinase C (PKC)-independent, manner. Furthermore, ozone-induced PTK and PKA activities but failed to induce PKC activity. In addition, our results suggest that ozone-induced PTK and PKA activities were reactive oxygen intermediate dependent and occurred in parallel, because specific inhibitors for PTK and PKA failed to block the other kinase's activity. These results indicate that PTK and PKA activities are early events in the signal transduction cascade mediating the ozone-induced activation of NF-kappaB and NF-IL6 as well as the release of interleukin 8.

Successfully treated sulphasalazine-induced fulminant hepatic failure, thrombocytopenia and erythroid hypoplasia with intravenous immunoglobulin

We report the simultaneous development of fulminant hepatic failure, thrombocytopenia and erythroid hypoplasia in a child treated with sulphasalazine. A 12-year-old girl with juvenile rheumatoid arthritis developed fulminant hepatic failure, thrombocytopenia and erythroid hypoplasia, which was confirmed by liver histology and bone marrow examination, 2 weeks after initiation of sulphasalazine therapy. The patient recovered after administration of high doses of intravenous immunoglobulin. This is the first reported case of the concurrent development of these complications associated with sulphasalazine hypersensitivity. The use of intravenous immunoglobulin may have helped in the treatment of this rare adverse effect of sulphasalazine.

Immunotoxicologic effects of inhaled chromium: role of particle solubility and co-exposure to ozone

Soluble and insoluble hexavalent chromium (Cr6+) agents are concomitantly released with ozone (O3) during welding. Although pulmonary/immunologic implications from exposure to each agent individually have been investigated, the effects from simultaneous exposure, as occurs under actual working conditions, are unclear. To investigate immunomodulatory effects of inhaled Cr6+, F-344 rats were exposed for 5 h/day, 5 days/week for 2 or 4 weeks to atmospheres containing soluble potassium chromate (K2CrO4) or insoluble barium chromate (BaCrO4), each alone at 360 micrograms Cr/m3 or in combination with 0.3 ppm O3. One day after the final exposure, rats were euthanized, their lungs were lavaged, and pulmonary macrophages (PAM) were recovered for assessment of basal and inducible functions. Rats inhaling K2CrO4-containing atmospheres had greater levels of total recoverable cells, neutrophils, and monocytes in bronchopulmonary lavage compared to rats exposed to insoluble Cr6+ atmospheres, O3 alone, or air; these rats also had a reduced percentage of PAM, although total PAM levels remained unaffected. Although Cr exposure-related changes in PAM functionality were evident, any dependence upon Cr solubility was variable. K2CrO4-containing atmospheres modulated PAM-inducible interleukins-1 and -6, and tumor necrosis factor-alpha production to a greater degree than those containing BaCrO4. Conversely, BaCrO4-containing atmospheres affected PAM basal nitric oxide production and interferon-gamma-primed/zymosan-stimulated reactive oxygen intermediate production to a greater extent than did those containing K2CrO4. In none of the PAM assays did co-inhalation of O3 result in a modulation of the effects obtained with either Cr6+ compound itself. The results indicate that, while immunomodulatory effects of inhaled Cr6+ upon PAM are related to particle solubility, the co-inhalation of O3 apparently does not cause further modifications of the metal-induced effects.

The human homologue for the Caenorhabditis elegans cul-4 gene is amplified and overexpressed in primary breast cancers

Amplification is a key mechanism whereby a cancer cell increases the message level of genes that confer a selective advantage when they are overexpressed. In breast cancer, there are many chromosome regions present in multiple copies relative to overall DNA copy number (amplicons), and their target genes are unknown. Using differential display, we have cloned and sequenced the full coding region of a candidate amplicon target gene located on chromosome 13. This candidate is the human homologue of the Caenorhabditis elegans cul-4 gene, cul-4A, a member of the novel cullin gene family, which is involved in cell cycle control of C. elegans. cul-4A was amplified and overexpressed in 3 of 14 breast cancer cell lines analyzed, and it was overexpressed in 8 additional cell lines in which it was not amplified. The latter observation, indicating that its overexpression can occur by mechanisms other than gene amplification, suggests that cul-4A plays a key role in carcinogenesis. Moreover, cul-4A was found to be amplified in 17 of 105 (16%) cases of untreated primary breast cancers, and 14 of 30 cases analyzed (47%) were shown by RNA in situ hybridization to overexpress cul-4A. These results suggest that up-regulation of cul-4A may play an important role in tumor progression.

Pulmonary and cardiovascular effects of acute exposure to concentrated ambient particulate matter in rats

To examine the biological plausibility of the adverse health effects of ambient particulate matter (PM), we have studied the cardio-pulmonary effects of PM in an animal model of pulmonary hypertension. Normal and monocrotaline-treated rats were exposed, nose-only, for 3 h to filtered air or concentrated ambient PM. At 3 h--but not 24 h--post-exposure, the percentage of neutrophils in peripheral blood was significantly elevated in PM-exposed animals while the percentage of lymphocytes was decreased with no change in white blood cell counts. These changes in white blood cell differential occurred in both normal and monocrotaline-treated animals. Small, but consistent changes in heart rate, but not core temperature, were observed after exposure to concentrated ambient PM. Pulmonary injury, as evidenced by increased protein levels in lavage fluid, occurred only in monocrotaline-treated animals exposed to > 360 microg/m3 PM. The observed pattern of hematological and cardiac changes suggests an activation of the sympathetic stress response.

Buffering capacity of coal and its acid-soluble Fe2+ content: possible role in coal workers' pneumoconiosis

Epidemiological studies have shown that the prevalence of coal workers' pneumoconiosis (CWP) differed remarkably between different coal mine regions despite comparable exposures to respirable dust. In the United States, CWP was found to be most common in Pennsylvania coal miners and least common in miners from Utah. The active component(s) responsible for the regional differences in CWP has not yet been identified. In the present study, we found that coals from Pennsylvania, compared with Utah coals, showed a much lower buffering capacity as determined by the amount of acid consumed in order to reach pH 4.5, which is the pH of the phagolysosomes of macrophages. Moreover, the coals from Pennsylvania released large amounts of Fe2+ in the acidified extract, whereas the coals from Utah released little Fe2+. Using electron spin resonance (ESR), we found that the coals from Pennsylvania, but not from Utah, were effective in oxidizing formate by a radical pathway. Two coals, one from Utah with high buffering capacity and low acid-soluble Fe2+ and the other from Pennsylvania with low buffering capacity and high acid-soluble Fe2+, were then selected for cell treatment. We found that human tracheal epithelial (HTE) cells treated with the coal from Pennsylvania (10 microg/cm2) showed a 36% increase in oxidant formation over the control as detected by dichlorofluorescein assay, whereas the coal from Utah had no effect. An electrophoretic mobility shift assay was used to test the binding affinity of nuclear proteins extracted from the coal-treated HTE cells to an oxidative stress-responsive transcription factor activator protein-1 (AP-1) element. The coal from Pennsylvania with high acid-soluble Fe2+ (1 microg/cm2) activated AP-1 to the same extent as 10 microM H2O2, while the coal from Utah without acid-soluble Fe2+ had no effect. These results support our hypothesis that the prevalence of CWP may be higher in coal workers exposed to coal with high acid-soluble Fe2+ and low buffering capacity than in workers exposed to coal with low acid-soluble Fe2+ and high buffering capacity.

Penetration enhancement by menthol combined with a solubilization effect in a mixed solvent system

The improvement in solubility of indomethacin due to the presence of menthol in various cosolvent systems consisting of water, alcohol and propylene glycol was examined by a mixture design in this study. A proper model to quantitatively describe the effect of menthol at different concentrations on the solubility of indomethacin was compared based on the statistical parameters provided by DESIGN-EXPERT. Then three cosolvent systems with the addition of menthol to solubilize indomethacin to extents of 1.0, 1.5 or 2.0% w/v were selected. The penetration of indomethacin through nude mouse skin from these three cosolvent systems with the addition of 0-12% menthol was investigated and followed by a discussion on the penetration mechanism. The results showed that menthol was able to improve drug solubility to different extents for different cosolvent systems. Optimally, a cosolvent system with an equal ratio of the three solvents, water, alcohol and propylene glycol, showed the highest extent of improvement in the solubility at all concentrations of menthol. The enhancement factors for indomethacin penetration due to menthol in different cosolvent systems were compared, based either on the permeation coefficient (Kp) or the separate overall effects on the skin (Flux). Both comparisons gave similar results. The influence of menthol was more significant compared to that of the cosolvent systems and the extent of this influence increased with an increase in the amount added, reaching a maximum at a specific amount of menthol for each different cosolvent system.

Microevolution of a standard strain of Cryptococcus neoformans resulting in differences in virulence and other phenotypes

Cryptococcus neoformans is a major fungal pathogen for patients with debilitated immune systems. However, no information is available on the stability of virulence or of phenotypes associated with virulence for C. neoformans laboratory strains. A serendipitous observation in our laboratory that one isolate of C. neoformans ATCC 24067 (strain 52D) became attenuated after continuous in vitro culture prompted us to perform a comparative study of nine strain 24067 isolates obtained from six different research laboratories. Each isolate was characterized by DNA typing, virulence for mice, proteinase production, extracellular protein synthesis, melanin synthesis, carbon assimilation pattern, antifungal drug susceptibility, colony morphology, growth rate, agglutination titers, phagocytosis by murine macrophages, capsule size, and capsular polysaccharide structure. All isolates had similar DNA typing patterns consistent with their assignment to the same strain, although minor chromosome size polymorphisms were observed in the electrophoretic karyotypes of two isolates. Several isolates had major differences in phenotypes that may be associated with virulence, including growth rate, capsule size, proteinase production, and melanization. These findings imply that C. neoformans is able to undergo rapid changes in vitro, probably as a result of adaptation to laboratory conditions, and suggest the need for careful attention to storage and maintenance conditions. In summary, our results indicate that C. neoformans (i) can become attenuated by in vitro culture and (ii) is capable of microevolution in vitro with the emergence of variants exhibiting new genotypic and phenotypic characteristics.

Two functionally independent pathways for lipopolysaccharide-dependent activation of mouse peritoneal macrophages

We have investigated the effects of human LPS-binding protein (LBP) and human bactericidal/permeability-increasing protein (BPI) on LPS-dependent activation of mouse thioglycolate-elicited peritoneal macrophages in vitro, in comparison with human PBMCs. Confirming earlier published studies, BPI inhibited, and LBP enhanced, the ability of LPS to stimulate PBMC production of the cytokines TNF-alpha and IL-6. In marked contrast to these results, under identical conditions of in vitro culture, both LBP and BPI suppressed, in a dose-dependent manner, the ability of LPS to stimulate cytokine production in mouse macrophages. Further, while human BPI also suppressed LPS-dependent NO secretion in mouse macrophages, human LBP had no inhibitory effect on NO secretion under conditions that inhibited TNF-alpha secretion. These data provide the first direct evidence that mouse macrophages may utilize two independent pathways in response to LPS, thus leading to different phenotypic responses.

Two functionally independent pathways for lipopolysaccharide-dependent activation of mouse peritoneal macrophages

We have investigated the effects of human LPS-binding protein (LBP) and human bactericidal/permeability-increasing protein (BPI) on LPS-dependent activation of mouse thioglycolate-elicited peritoneal macrophages in vitro, in comparison with human PBMCs. Confirming earlier published studies, BPI inhibited, and LBP enhanced, the ability of LPS to stimulate PBMC production of the cytokines TNF-alpha and IL-6. In marked contrast to these results, under identical conditions of in vitro culture, both LBP and BPI suppressed, in a dose-dependent manner, the ability of LPS to stimulate cytokine production in mouse macrophages. Further, while human BPI also suppressed LPS-dependent NO secretion in mouse macrophages, human LBP had no inhibitory effect on NO secretion under conditions that inhibited TNF-alpha secretion. These data provide the first direct evidence that mouse macrophages may utilize two independent pathways in response to LPS, thus leading to different phenotypic responses.

Serum osteocalcin levels of normal children in Taiwan

Osteocalcin is mainly secreted by osteoblasts, and then diffuses into blood which can be detected by several experimental methods. This study determined the osteocalcin level by solid phase fluorescent immunosorbent assay (Pharmacia CAP; Sweden), a well-established and accurate laboratory method for determining the minor concentration of substances in blood. A total of 332 healthy children were enrolled in the study, including 176 boys and 156 girls ranging in age from one to fifteen years. It was concluded that (1) quantitative osteocalcin (OCs) value varies between 30.2 to 41.0 ng/ml; (2) there is an incremental tendency in both sexes until puberty; (3) girls generally have a higher osteocalcin level than boys before mid-puberty (2-12 years old). The differences are statistically significant.

Comparison of inflammatory lung responses in Wistar rats and C57 and DBA mice following acute exposure to cadmium oxide fumes

Inhalation of cadmium oxide (CdO) is a significant form of human exposure to cadmium (Cd). Furthermore, there is epidemiological and experimental data relating Cd inhalation with lung cancer. Animal studies indicate that rats are more susceptible to Cd-induced lung cancer than mice, but interstrain sensitivity differences to Cd-induced pulmonary inflammation or carcinogenesis have not been addressed in either species. We compared pulmonary inflammatory processes in Wistar Furth (WF) rats with those in C57 and DBA mice exposed to freshly generated CdO fumes in nose-only inhalation chambers. Animals were exposed to 1 mg Cd/m3 for 3 hr and terminated immediately or 1, 3, and 5 days after exposure. Control animals were exposed to air/argon furnace gases. Cd-induced lung injury was assessed by bronchoalveolar lavage fluid (BALF) analyses, histopathology, and immunohistochemical detection of cell proliferation. Inhalation of CdO resulted in pulmonary inflammatory processes that varied widely across species and strains. C57 mice responded with faster and greater influx of neutrophils and proliferation of alveolar macrophages, type II epithelial cells, and bronchiolar epithelial cells compared to DBA mice or WF rats. DBA mice retained a greater percentage of inhaled Cd in the lungs and presented higher levels of BALF protein than C57 mice or rats. In comparison to mice, WF rats responded with a more transient inflammatory response in BALF parameters and higher degree of acute inflammation in lung tissue. The more pronounced proliferation of alveolar and bronchiolar epithelial cells observed in C57 mice might indicate higher susceptibility of this mice strain to Cd-induced lung carcinogenesis compared to DBA mice or WF rats. Furthermore, the present results of fewer inflammatory cells and lower proliferation of epithelial cells in DBA mice in association with our previous observation of higher Cd-induced metallothionein protein in this strain suggest that DBA might be less susceptible to the pulmonary carcinogenic effects of inhaled Cd than C57 mice or WF rats. We conclude that mice might not necessarily be more resistant than rats to the carcinogenic effects of inhaled Cd, since intraspecies susceptibility differences are strongly suggested by the present data. An extrapolation of this conclusion is that genetic variations in the human population may determine individual sensitivity differences to inhaled Cd.