Biomedical subjects

V M Kosma

Publications and source records attributed to V M Kosma.

At least 37 records · Page 2Linked to original sources

PubMed2000

Loss of heterozygosity at chromosomes 3, 6, 8, 11, 16, and 17 in ovarian cancer: correlation to clinicopathological variables.

Tumor specimens from 78 epithelial ovarian cancer patients were examined for loss of heterozygosity (LOH) at 11 microsatellite markers at chromosomes 3p14.2, 6q27, 8p12, 11p15.5, 11q23.1-q24, 16q24.3, and 17p13.1, to evaluate the involvement, possible clustering, and prognostic significance of these lesions in the progression of the disease. The LOH analysis was performed on polymerase chain reaction (PCR)-amplified DNA from sections of paraffin-embedded tumor and normal tissue pairs. In addition to primary tumors, specimens of metastatic tissues were studied from 19 patients. In the combined results from primary and metastatic tumors, LOH frequencies varied between 31% (6q27) and 69% (17p13.1). Only LOH at chromosomal regions 3p14.2 (D3S1300), 11p15.5 (D11S1318), 11q23.3-q24 (D11S1340 and D11S912), 16q24.3 (D16S476 and D16S3028), and 17p13.1 (D17S938) was associated with an adverse disease course. Our results indicate that LOH at 17p13.1 occurs independently from the other chromosomal sites studied, and is an early event in ovarian tumorigenesis. The LOH at 16q24.3, 11q23.3/q24, and 11p15.5 seems to occur later. The LOH at 11p15.5 and 11q23.3 was associated with reduced cancer-specific survival time; therefore, the studied markers could be located close to genes with influence on patient survival. Of the studied chromosomal regions, the most important tumor suppressor genes involved in the evolution of ovarian cancer appear to be located on chromosomes 11, 16, and 17. The genetic heterogeneity observed in primary and metastatic specimens demonstrates that there are multiple pathways involved in the progression of ovarian cancer.

Chromosome Deletion↗

PubMed2000

High levels of stromal hyaluronan predict poor disease outcome in epithelial ovarian cancer.

Several malignant tumors accumulate hyaluronan, a matrix component suggested to promote cancer cell migration and growth. To explore the potential clinical importance of this concept, we assessed the hyaluronan levels in epithelial ovarian cancer. A biotinylated affinity probe specific for hyaluronan was prepared and applied to histological sections of 309 epithelial ovarian cancers and 45 matched metastatic lesions. The staining was scored according to the percentage area of strong hyaluronan signal of total peri- and intratumoral stroma as low (<35%), moderate (35-75%), or high (>75%). Low, moderate, and high levels of stromal hyaluronan were observed in 95, 116, and 98 carcinomas, respectively. The high stromal hyaluronan level was significantly associated with poor differentiation, serous histological type, advanced stage, and large primary residual tumor, whereas it was not correlated with high CD44 expression on cancer cells. The 5-year outlook of the disease deteriorated with increasing stromal hyaluronan levels for both overall (45% versus 39% versus 26%; P = 0.002) and recurrence-free (66% versus 56% versus 40%; P = 0.008) survival. High levels of stromal hyaluronan were more frequent in metastatic lesions than in primary tumors (z = -3.9; P = 0.0001). In Cox's multivariate analyses, high level of stromal hyaluronan was an independent prognostic factor in all patients, as well as in stage-specific subgroups. These results suggest that stromal hyaluronan accumulation may be a powerful enhancer of tumor progression and, as such, provides a novel, independent prognostic marker and a potential target of therapy.

Analysis of Variance↗

PubMed2000

Reduced CD44 standard expression is associated with tumour recurrence and unfavourable outcome in differentiated thyroid carcinoma.

CD44 was detected with an antibody recognizing all forms of CD44 (CD44 standard) and others specific for its v3 and v6 variant isoforms; their prognostic value was evaluated in 213 patients with differentiated thyroid carcinoma (DTC). The staining patterns of CD44 standard (s) and CD44v6 in tumour tissue were quite similar, 176 cases (83%) being highly positive for CD44s and 153 cases (72%) for CD44v6. Only 18 (9%) tumours showed high expression of CD44v3. Papillary carcinomas were significantly more often high expressors of CD44s and CD44v6 than follicular carcinomas (p<0.001 for both). Age older than 60 years, distant metastases, and advanced pTNM stage were related to loss of expression of CD44s (p<0.001, p=0.021, and p=0.003, respectively). Tumour recurrence and cancer-related mortality were related to the reduced level of CD44s (p=0.049 and p=0.042). CD44v3 did not associate with any of the clinicopathological factors. In univariate analysis, CD44s was the only significant prognostic factor for disease-free survival (p=0.0488). In multivariate analysis, CD44s and thyroglobulin level were significant prognostic factors for disease-free survival (p=0.040 and p<0.001, respectively). The reduced level of CD44s in DTC patients seems to be an independent prognostic factor for unfavourable disease outcome.

Adolescent↗

PubMed2000

No consistent pattern of mutations in p53 and ras genes in liver tumors of rat treated with the drinking water mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX).

The frequency of point mutations in p53 (exons 4-7) and in Ki-ras, Ha-ras, and N-ras (exons 1 and 2) and the expression of p53 protein were evaluated in the liver tumors of Wistar rats of a 104-week carcinogenicity study on 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a chlorine disinfection by-product in drinking water. Mutations were analyzed in 16 hepatocellular adenomas, 7 hepatocellular carcinomas, 23 cholangiomas, and 2 cholangiocarcinomas of the MX-treated animals and one hepatocellular carcinoma and cholangiocarcinoma in control animals using PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) or PCR-TGGE (temperature gradient gel electrophoresis) and direct sequencing. The expression of the p53 protein (wild-type and mutated protein) was detected by immunohistochemistry (CM5 antibody). The expression of p53 and that of the proliferating cell nuclear antigen (PCNA, 19 A2) were also evaluated in livers of female animals exposed to MX for 1 week, 3 weeks, or 18 weeks. Altogether, four mutations were found in p53 in three tumors, in two hepatocellular adenomas, and one cholangiocarcinoma, all in females receiving the highest MX dose (6. 6 mg/kg/day) of the study. Three of the mutations were G:C --> A:T transitions and one was an A:T --> T:A transversion. The mutations were scattered at different codons and positions of the codon. One hepatocellular adenoma contained two p53 mutations. All cholangiomas and cholangiocarcinomas, but no hepatocellular adenomas and carcinomas, overexpressed the p53 protein. MX treatment did not induce p53 expression at any age in the liver or alter the expression of the PCNA in the liver of younger animals. The p53 protein was overexpressed in hyperplastic bile ducts in aged rats but not in bile ducts of younger rats (up to 24 weeks). No mutations were observed in either Ki-ras, Ha-ras, or N-ras of the liver tumors. These data suggest that point mutations in p53, Ki-ras, Ha-ras, and N-ras are not involved in the MX-induced liver carcinogenesis in rats.

Animals↗

PubMed2000

Evaluation of p21WAF1/CIP1 and cyclin D1 expression in the progression of superficial bladder cancer. Finbladder Group.

Immunoreactivity of p21WAF1/CIP1 and cyclin D1 proteins was assessed in a cohort of 207 patients with superficial (pTa-pT1) bladder cancer followed up for a mean of 4.9 years. The results of the immunostainings were compared with T category, WHO grade, tumor cell proliferation rate (MIB-1 score), the expressions of p53 and bcl-2 as well as survival. Sixty-eight percent and 75% of the tumors were p21WAF1/CIP1 positive (> or = 5% of cells positive) and cyclin D1 positive (> or = 10% of cells positive), respectively. The p21WAF1/CIP1 expression was related to cyclin D1 immunolabelling (P < 0.001) but not to the other variables studied. The expression of cyclin D1 was inversely associated with T category (P = 0.001), WHO grade (P = 0.006), MIB-1 score (P = 0.014), p53 expression (P = 0.001), and bcl-2 (P = 0.011) immunoreactivity. In univariate analysis, T category (P = 0.0001), WHO grade (P < 0.0001), MIB-1 score (P < 0.0001), bcl-2 (P = 0.0092), p53 (P = 0.0016) and p21WAF1/CIP1 (P = 0.009) expressions were significant prognostic factors with regard to tumor progression, whereas cyclin D1 was without any prognostic significance (P = 0.1). Out of 123 p21 positive tumors 21 progressed, whereas only 2 out of 58 p21 negative tumors progressed. In multivariate analysis, the MIB-1 score was the only independent predictor of cancer-specific survival (P = 0.03), whereas tumor grade (P = 0.002) and cyclin D1 expression (P = 0.04) were independent predictors of tumor recurrence. Only the WHO grade (P = 0.04) retained its prognostic value indicating the risk of progression. We suggest that in superficial bladder cancer p21WAF1/CIP1 and cyclin D1 immunohistochemistry provide no additional prognostic information compared with already established prognostic factors for predicting the risk of progressive disease.

Adult↗

PubMed2000

Merkel cell carcinoma of the auricle.

Merkel cell carcinoma is a rare, although increasingly recognized, malignant tumor of the skin. The most common site of occurrence is the head and neck (50%). Only five cases of this tumor on the auricle have been reported previously. We present a further such case. The incidence, clinical features, diagnosis, prognosis, and treatment of the Merkel cell carcinoma are discussed.

Aged↗

PubMed2000

Reduced level of CD44 and hyaluronan associated with unfavorable prognosis in clinical stage I cutaneous melanoma.

The cell surface glycoprotein CD44 and its ligand, hyaluronan (HA), enhance growth and metastatic capacity of melanoma cells in vitro, but their clinical significance in primary cutaneous melanoma is still unclear. Therefore, we studied whether the levels of CD44 and HA associate with disease progression and survival of cutaneous melanoma. A series of 292 clinical stage I cutaneous melanomas was analyzed by immunohistochemistry using an anti-CD44H antibody (clone 2C5). HA was demonstrated histochemically using a biotinylated HA-specific affinity probe (bHABC). The reduced staining levels of CD44 and HA were associated with each other and indicators of progressive disease. Reduced CD44 and HA level, high tumor thickness, high pT category, high Clark's level, bleeding, and male gender predicted short univariate recurrence free survival (RFS) and overall survival (OS). In Cox's multivariate analysis (N: = 251), the decreased level of CD44, high tumor thickness, and bleeding predicted independently short RFS. High tumor thickness and bleeding were associated with short OS. We conclude that the reduced cell surface CD44 and HA levels associate with poor prognosis in clinical stage I cutaneous melanoma. The notion that the decreased level of CD44 independently predicts short RFS suggests that reduced cell surface CD44 enhances the spreading potential in localized cutaneous melanoma and that quantification of CD44 offers a prognostic tool for its clinical evaluation.

Adult↗

PubMed2000

Hyaluronan in peritumoral stroma and malignant cells associates with breast cancer spreading and predicts survival.

Hyaluronan (HA) is an extracellular matrix polysaccharide that promotes cell migration through its cell surface receptors and by effecting changes in the physical environment. HA expression is frequently increased in malignant tumors, whereas its association with the invasive potential and patient outcome in breast cancer has not been reported. The localization and signal intensity of HA was analyzed in 143 paraffin-embedded tumor samples of human breast carcinoma using a biotinylated HA-specific probe. In the immediate peritumoral stroma, HA signal was moderately or strongly increased in 39% and 56% of the cases, respectively. Normal ductal epithelium showed no HA, whereas in 57% of the tumors at least some of the carcinoma cells were HA positive. The intensity of the stromal HA signal and the presence of cell-associated HA were both significantly related to poor differentiation of the tumors, axillary lymph node positivity, and short overall survival of the patients. In Cox's multivariate analysis, both the intensity of stromal HA signal alone and that combined with the HA positivity in tumor cells were independent prognostic factors for overall survival. These results suggest that HA is directly involved in the spreading of breast cancer and may offer a potential target for new therapies.

Axilla↗

PubMed2000

The morphological changes in rat bladder after photodynamic therapy with 5-aminolaevulinic acid-induced protoporphyrin IX.

OBJECTIVE: To assess the optimum light energy needed to induce only superficial bladder wall damage during photodynamic therapy (PDT) as a treatment for bladder cancer. Materials and methods The urinary bladder (with normal epithelium) of 64 female rats was treated with PDT using a continuous-wave argon-ion laser as an energy source and aminolaevulinic acid (ALA)-induced protoporphyrin IX photosensitizer. Four hours after the intravenous administration of ALA (300 mg/kg) the bladders were intravesically exposed to light fluences of 20-80 J/cm2. The control rats received no ALA and were exposed to 20 J/cm2 light. After 1, 3, 7 and 21 days the animals were killed and the morphological changes in bladder wall analysed both macroscopically and using light and scanning electron microscopy. RESULTS: At the dose of ALA given, a fluence of 20-40 J/cm2 caused mainly superficial damage, whereas 80 J/cm2 produced full-thickness injuries to the bladder wall. The maximum effect of PDT occurred after 1 and 3 days of irradiation. After 3 weeks of PDT the histology showed few full-thickness injuries and only in those treated with 80 J/cm2 light. CONCLUSION: These results indicate that PDT can be used to safely induce a selective superficial removal of bladder mucosa with no fibrotic effects on detrusor musculature, when optimum photosensitizing drug and fluences are used. These findings support the use of PDT in the therapy of superficial bladder cancer.

Aminolevulinic Acid↗

PubMed2000

The prognostic value of inducible nitric oxide synthase in local prostate cancer.

OBJECTIVE: To compare the clinical and histological data from patients with prostate cancer with the results of the immunohistochemical analysis of inducible nitric oxide synthase (iNOS), and thus determine the prognostic value of iNOS. PATIENTS AND METHODS: The study included 82 patients (mean age 64.6 years, SD 6.1) with local prostate cancer treated by radical prostatectomy in two Finnish hospitals. Their mean (SD) follow-up was 3.3 (2.2) years. An immunohistochemical method was used to detect the expression of iNOS in these specimens, and the expression graded according to staining intensity as none, weak or strong. RESULTS: There was weak or strong expression of iNOS in 25 (31%) and 56 (68%) of the patients, respectively, and one specimen was negative for iNOS. Strong expression of iNOS was related to high a preoperative prostate specific antigen (PSA) level (P = 0.006) and high pT classification (P < 0.001), but not to nodal status, grade, seminal vesicle or capsular invasion, surgical margin status, perineural infiltration, tumour infiltrating lymphocytes or proliferation rate of cancer cells. A PSA failure was detected in 29 patients but was not predicted by iNOS expression. A Cox multivariate analysis showed that surgical margin positivity, seminal vesicle involvement and number of tumour infiltrating lymphocytes predicted the PSA failure. CONCLUSION: A high expression of iNOS was related to a high pT classification and the preoperative PSA level but not to other established prognostic factors; iNOS expression was not a predictor of PSA failure in patients with local prostate cancer.

Disease-Free Survival↗

PubMed2000

Reduced expression of CD44v3 variant isoform is associated with unfavorable outcome in non-small cell lung carcinoma.

The expression of CD44 standard form (CD44s) and variant isoforms v3 and v6 was analyzed in 233 resected non-small cell lung carcinoma (NSCLC) specimens by immunohistochemistry (IHC), and the mRNA status of CD44v3 and CD44v6 in a cohort of samples was determined by in situ hybridization (ISH) and further confirmed by reverse transcriptase polymerase chain reaction (RT-PCR). The expression of CD44s, CD44v3, and CD44v6 was correlated with clinicopathologic variables and survival. The expression of CD44v3 and v6 was reduced in 97% and 90% of the adenocarcinomas and in 86% and 74% of the large cell/anaplastic carcinomas, respectively, as compared with squamous cell carcinomas, where they were reduced in 53% and 51% of the cases (P = .0001 and P = .004 for v3 and v6). The corresponding values for CD44s were 92%, 70%, and 51%, respectively (P = .011). The reduced CD44s and CD44v6 expression was associated with lymph node metastases (P = .03 and P = .005, respectively) and the reduced expression of CD44s also with advanced stage (P = .04). Recurrences during the follow-up were more often found within the tumors showing reduced expression of CD44v3 (P = .04). Combining ISH and IHC results showed that CD44v3 and v6 mRNA were not always processed into protein, suggesting a regulation disturbance posttranscriptionally since malignant transformation of cells has occurred. In survival analyses, the reduced expression of CD44s and CD44v3 was associated with a shortened disease-free survival (P = .04 and P = .01, respectively). In multivariate analysis, CD44v3 retained its independent prognostic value (P = .03). These results emphasize the value of CD44, and especially the v3 variant isoform in the behavior of NSCLC.

Adult↗

PubMed2000

Failure in post-transcriptional processing is a possible inactivation mechanism of AP-2alpha in cutaneous melanoma.

The loss of transcription factor AP-2alpha expression has been shown to associate with tumourigenicity of melanoma cell lines and poor prognosis in primary cutaneous melanoma. Altogether these findings suggest that the gene encoding AP-2alpha (TFAP2A) acts as a tumour suppressor in melanoma. To learn more of AP-2alpha's down-regulation mechanisms, we compared the immunohistochemical AP-2alpha protein expression patterns with the corresponding mRNA expression detected by in situ hybridization in 52 primary melanomas. Of the 25 samples with AP-2alpha protein negative areas, 16 (64%) expressed mRNA throughout the consecutive section. Nine specimens (36%) contained equally mRNA- and protein-negative areas, suggesting that the loss of AP-2alpha protein associated with lack of the mRNA transcript. The highly AP-2alpha protein-positive tumours (n = 27) were concordantly mRNA positive in 25 (92.6%) cases. Thirteen primary tumours were further analysed using microsatellite markers D6S470 and D6S263 for loss of heterozygosity (LOH) of a locus harbouring TFAP2A. LOHs or chromosome 6 monosomy were found in four out of five (80%) informative AP-2alpha mRNA- and protein-negative tumour areas, but also within five out of 13 (38%) informative AP-2alpha mRNA-positive tumour areas. This chromosome region is thus suggestive of harbouring a putative tumour suppressor gene of cutaneous melanoma, but this referring specifically to TFAP2A could not be completely verified in this analysis. We conclude that a failure in post-transcriptional processing of AP-2alpha is a possible inactivation mechanism of AP-2alpha in cutaneous melanoma.

DNA-Binding Proteins↗

PubMed2000

Expression of transcription factor AP-2alpha predicts survival in epithelial ovarian cancer.

The 52-kDa activator protein (AP)-2 is a DNA-binding transcription factor which has been reported to have growth inhibitory effects in cancer cell lines and in human tumours. In this study the expression of AP-2alpha was analysed in 303 epithelial ovarian carcinomas by immunohistochemistry (IHC) with a polyclonal AP-2alpha antibody and its mRNA status was determined by in situ hybridization (ISH) and reverse transcriptase-polymerase chain reaction (RT-PCR). The immunohistochemical expression of AP-2alpha was correlated with clinicopathological variables, p21/WAF1 protein expression and survival. In normal ovaries, epithelial cells expressed AP-2alpha protein only in the cytoplasm. In carcinomas nuclear AP-2alpha expression was observed in 28% of the cases although cytoplasmic expression was more common (51%). The expression of AP-2alpha varied according to the histological subtype and differentiation. AP-2alpha and p21/WAF1 expressions did not correlate with each other. Both in univariate (P = 0.002) and multivariate analyses (relative risks (RR) 1.6, 95% confidence interval (CI) 1.13-2.18, P= 0.007) the high cytoplasmic AP-2alpha expression favoured the overall survival. In contrast, the nuclear AP-2alpha expression combined with low cytoplasmic expression increased the risk of dying of ovarian cancer (RR = 2.10, 95% CI 1.13-3.83, P= 0.018). The shift in the expression pattern of AP-2alpha (nuclear vs cytoplasmic) in carcinomas points out to the possibility that this transcription factor may be used by oncogenes in certain histological subtypes. Based on the mRNA analyses, the incomplete expression and translation of AP-2alpha in ovarian cancer may be due to post-transcriptional regulation.

Aged↗

PubMed2000

Expression of inducible nitric oxide synthase in colorectal cancer and its association with prognosis.

BACKGROUND: The expression of inducible nitric oxide synthase (iNOS) has been reported to be altered in a number of tumours, but its role in tumour biology is still unclear. METHODS: iNOS was studied in a series of 157 colorectal carcinoma patients and its relation to tumour grade, stage, cell cycle regulators, cell proliferation as well as survival was assessed. RESULTS: iNOS intensity was moderate or intense in 37% of the tumours. iNOS intensity and percentage of positive cells were higher in Dukes A and B tumours than in Dukes C and D tumours, and low iNOS expression intensity was related to high histological grade. iNOS expression correlated positively with cell cycle regulators p21 and AP-2. There was also a high iNOS expression intensity and high fraction of iNOS positive cells in tumours with a high amount of tumour infiltrating lymphocytes (TILs). The cancer related survival was significantly lower among patients with a low signal for iNOS and low iNOS percentage in tumour epithelium. In multivariate analysis iNOS was not an independent prognostic factor. CONCLUSIONS: These results suggest that iNOS has a protective role in colorectal carcinogenesis, but further studies are required to establish the clinical significance of iNOS in colorectal cancer.

Adenocarcinoma↗

PubMed2000

Is the subsite distribution of laryngeal cancer related to smoking habits?

In Finland traditionally as many as two-thirds of laryngeal cancers have been considered to be supraglottic, while in other countries the majority are glottic. The Finnish observation is based on clinical series diagnosed and treated mainly before the 1960s. The aim of our study was to evaluate the present situation. This study consisted of 279 patients treated in Eastern Finland between 1975 and 1994 and included 145 (52%) glottic, 124 (44%) supraglottic and 10 (4%) subglottic tumours in 260 (93%) men and 19 (7%) women. During this study period, the proportion of glottic tumours remained stable in men but increased in women. The change in smoking habits seems to be the most important reason for the shift from supraglottic to glottic tumours.

Adult↗

PubMed2000

Combined respiratory effects of cold air with SO(2) or NO(2) in repeated 10-minute exposures of hyperventilating guinea pigs.

Previous studies in asthmatic subjects and guinea pigs have demonstrated attenuation of bronchoconstriction in repeated exposures to clean cold dry air. In the present animal study, we have simulated short-lasting human exposures to subfreezing urban air containing sulfur dioxide (SO(2)) and nitrogen dioxide (NO(2)). The anesthetized, paralyzed, and mechanically ventilated guinea pigs had 4 consecutive 10-min exposures either to clean cold dry air or to cold air with graded concentrations of SO(2) (0-5 ppm) or NO(2) (0-4 ppm). Peak expiratory flow (PEF) and tidal volume (V(T)) were continuously measured both during and after highly controlled exposures. Bronchoalveolar lavage fluid (BALF) and histological samples were obtained after finishing the consecutive exposures. Cold air + SO(2) at 1 and 2.5 ppm (n = 12) produced immediate concentration-dependent increases in the lung function responses compared to the preceding single exposure to clean cold dry air in the same animals (DeltaPEF = -32.7 +/- 6.1% and -35.6 +/- 6.5% vs. -27.0 +/- 3.1%; DeltaV(T) = -22.4 +/- 4.4% and -28.3 +/- 4.7% vs. -18.1 +/- 2.9%). In a multivariate analysis, these responses were significantly larger than the attenuated lung function responses to the corresponding second and third clean cold dry air exposures (p <. 05). The fourth exposure to cold air + SO(2) at 5 ppm produced a smaller response (DeltaPEF = -25.3 +/- 4.8% and DeltaV(T) = -17.8 +/- 3.7%) than cold air with the lower SO(2) concentrations. Cold air + NO(2) at 1 and 2.5 ppm (n = 12) produced roughly similar lung function responses to the preceding single exposure to clean cold dry air in the same animals, and there was no significant attenuation of bronchoconstriction as with the consecutive exposures to clean cold dry air. The largest decreases in lung functions (DeltaPEF = -33.8 +/- 6.7% and DeltaV(T) = -26.2 +/- 6.8%) were recorded during the fourth exposure, which was to cold air + NO(2) at 4 ppm. In the cold air + SO(2) group, there was a significantly lower proportion of macrophages in the differential count of BALF white cells compared to the clean cold dry air group. In addition, there was eosinophilic infiltration within and below the tracheal epithelium in all guinea pigs exposed to either clean cold dry air, cold air + SO(2), or cold air + NO(2). In conclusion, the addition of moderate concentrations of SO(2) or NO(2) to clean cold dry air counteracted the attenuation of bronchoconstriction induced by repeated cold dry air exposures in guinea pigs. Cold air + SO(2) also decreased the proportion of macrophages in BALF white cells.

Air Pollutants↗

PubMed2000

Combined respiratory effects of cold air with SO(2) or NO(2) in single 1-hour exposures of hyperventilating guinea pigs.

The present study is a continuation of our previous experiments on repeated 10-min exposures of anesthetized, mechanically ventilated guinea pigs to clean cold dry air (Hälinen et al., 2000a), and to cold air plus gaseous air pollutants (Hälinen et al., 2000b). This time we made continuous 60-min exposures to clean cold dry air, cold air + SO(2) at 1 ppm, cold air + NO(2) at 1 ppm, and warm humid air + NO(2) at 1 ppm, and focused on responses at 10-60 min. Clean cold dry air and cold air + pollutants (n = 8-9 in each group) produced similar cooling in the guinea pig lower respiratory tract. The decreases in intratracheal temperature (T(tr)) reached a plateau at 20 min with mean maximal decreases of 9.7-11.3 degrees C from the pre-exposure control values of 36.0-37.3 degrees C. In contrast, there were progressive decreases in esophageal temperature (T(oe)) during the exposures, indicating constant conductive and evaporative heat losses from the tracheobronchial tissues. The mean maximal decreases in T(oe) were 1.2-1.4 degrees C from the preexposure control values of 37.8-38.0 degrees C. Clean cold dry air induced 4. 5-10.8% mean decreases in peak expiratory flow (PEF) at 10-60 min of exposure, which were statistically nonsignificant due to a relatively large variation between animals. Cold air + SO(2) at 1 ppm induced a mean decrease of 11.4% in PEF at 10 min (p <.05), which was spontaneously abolished during the next 10 min of exposure. Cold air + NO(2) at 1 ppm caused no decrease, but in fact small, nonsignificant increases in PEF at 30-60 min of exposure. Cold air + NO(2) at 1 ppm, and to some extent also cold air + SO(2) at 1 ppm, attenuated significantly the mechanical ventilation induced gradual decrease in tidal volume (V(T)), when compared to clean cold dry air exposure. Cold air + NO(2) at 1 ppm, but not warm humid air + NO(2) at 1 ppm, increased significantly the proportion of macrophages in the differential count of bronchoalveolar lavage fluid (BALF) white cells when compared to both clean warm humid air and cold dry air. None of the exposure conditions caused morphological or inflammatory changes in the respiratory tissues. In conclusion, continuous 60-min exposures to clean cold dry air, cold air + SO(2), and cold air + NO(2) produced weaker functional effects on the lower respiratory tract of guinea pigs than our previous consecutive 10-min exposures to these air conditions. After the first 10 min, there was a strong attenuation of the bronchoconstrictor responses, especially to cold air + NO(2) at 1 ppm. The small airway effects of prolonged mechanical ventilation were significantly modified by NO(2) at 1 ppm in both cold dry and warm humid breathing air. Finally, cold air + NO(2) at 1 ppm increased the proportion of macrophages in BALF white cells.

Air Pollutants↗

PubMed2000

Enzyme replacement therapy in a mouse model of aspartylglycosaminuria.

Aspartylglycosaminuria (AGU), the most common lysosomal disorder of glycoprotein degradation, is caused by deficient activity of glycosylasparaginase (AGA). AGA-deficient mice share most of the clinical, biochemical and histopathologic characteristics of human AGU disease. In the current study, recombinant human AGA administered i.v. to adult AGU mice disappeared from the systemic circulation of the animals in two phases predominantly into non-neuronal tissues, which were rapidly cleared from storage compound aspartylglucosamine. Even a single AGA injection reduced the amount of aspartylglucosamine in the liver and spleen of AGU mice by 90% and 80%, respectively. Quantitative biochemical analyses along with histological and immunohistochemical studies demonstrated that the pathophysiologic characteristics of AGU were effectively corrected in non-neuronal tissues of AGU mice during 2 wk of AGA therapy. At the same time, AGA activity increased to 10% of that in normal brain tissue and the accumulation of aspartylglucosamine was reduced by 20% in total brain of the treated animals. Immunohistochemical studies suggested that the corrective enzyme was widely distributed within the brain tissue. These findings suggest that AGU may be correctable by enzyme therapy.-Dunder, U., Kaartinen, V., Valtonen, P., Väänänen, E., Kosma, V.-M., Heisterkamp, N., Groffen, J., Mononen, I. Enzyme replacement therapy in a mouse model of aspartylglycosaminuria.

Acetylglucosamine↗