Multivariate analysis of bcl-2, apoptosis, P53 and HER-2/neu in breast cancer: a short-term follow-up

BACKGROUND

Several molecular genetic alterations in breast cancer, including aneuploidy, altered apoptosis, aberrant expression of p53, HER-2/neu and Bcl-2, have been associated with poor prognosis in breast cancer patients. To determine the importance of molecular-genetic factors relative to more traditional surgical-pathological prognostic factors, multivariate analysis was performed.

PATIENTS AND METHODS

Ninety-four fresh tissue samples of primary breast carcinoma were studied with flow cytometry for DNA ploidy. On the same specimens, steroid hormone receptors (ER and PR) were measured in the cytosol fraction using Abbott ELISA assays. HER-2/neu was determined in the membrane fraction and mutant p53 protein in the nuclear fraction, both, by Oncogene Science ELIZA procedures. Bcl-2 and apoptosis (cell death) were measured in cell lysates by Oncogene Science & Boehringer Mannheim ELISA assays. In addition, information regarding surgical-pathological features of the tumor was obtained. Multivariate analysis using an unconditional logistic regression model was done to identify variables predictive of poor prognosis.

RESULTS

Using univariate analysis, histological grade, tumor stage, lymph node status, HER-2/neu and mutant p53 were predictive of poor short-term prognosis. By multivariate analysis, tumor stage, lymph node status and HER-2/neu were independent factors. Grade subgroup analysis versus time of relapse, illustrated a predictive value of Bcl-2 in only low-grade tumors while apoptosis was significant in high-grade type.

CONCLUSION

Among a panel of molecular-genetic factors investigated, HER-2/neu was the most strongly predictive of poor short-term prognosis in breast cancer. Patients with HER-2/neu-positive tumors can benefit from Herceptin therapy.

Human papillomavirus infection among Egyptian females with cervical carcinoma: relationship to spontaneous apoptosis and TNF-alpha

OBJECTIVES

This study was designed to detect HPV type-16 in Cervical carcinoma (CC) tissue specimens. The results were correlated with clinicopathological parameters of the carcinoma, with spontaneous apoptosis and with immunoreactivity to TNF-alpha antibodies.

METHODS

Fresh frozen tissue specimens representing 30 cases of cervical carcinoma as well as 20 normal cervical tissues (NCT) were the subjects of this study. HPV-16 DNA was detected by Polymerase Chain Reaction (PCR). The occurrence of spontaneous apoptotic cell death was analyzed by the apoptosis assay. Apoptotic cells were also counted by light microscopy and the apoptotic index (AI) was calculated. Electron microscopy was used to confirm the morphology of apoptotic cells. TNF-alpha was quantified using EIA kit.

RESULTS

HPV-16 DNA was more frequent in CC than in NCT. No correlation was observed between HPV infection and grade, stage or pathologic type of CC. The occurrence of spontaneous apoptosis was significantly higher in CC than in NCT, where it was correlated to advanced tumor stage and tumor pathology being more in adenocarcinoma (AC) than in squamous cell carcinoma (SCC). Moreover, AI was negatively correlated to HPV-16 infection. TNF-alpha levels were significantly higher in CC vs. NCT, where they were positively correlated to advanced tumor stage. TNF-alpha levels were correlated to DNA fragmentation and AI (r = 0.47 and 0.57 respectively). A cut-off value for TNF-alpha was calculated to be 9.1 pg/mg protein (using ROC curve). At the determined cut-off point the sensitivity was 70% and the specificity was 80%.

CONCLUSIONS

HPV infection, high levels of TNF-alpha and spontaneous apoptosis were strongly associated with malignant phenotype of cervical tissues. Rate of spontaneous apoptosis was higher in AC compared to SCC. On the other hand, HPV negativity was correlated with AI. Moreover, TNF-alpha and apoptotic cell death were correlated to each other as well as to tumor progression. No correlation was detected between TNF-alpha and HPV-16 infection.

Telomerase activity, and tissue polypeptide specific antigen (TPS) in Egyptian breast cancer patients

OBJECTIVES

Breast cancer is the most common malignancy among Egyptian women. The aim of this study is to evaluate the role of both telomerase and TPS estimation in assessment of breast cancer.

METHODS

The study included 40 patients with breast cancer, and 20 patients with benign breast diseases. Telomerase activity in breast tissues was assessed using TRAP assay. TPS was measured in sera of the patients by ELISA.

RESULTS

Telomerase positivity was 15% in benign group vs. 60% in malignant group (p = 0.0009). It was significantly correlated to stage, and lymph node status (p < 0.02). Telomerase positivity showed significant correlation to tumor recurrence (p = 0.0076) in a follow-up period of 36 months. Mean rank of TPS was significantly higher in malignant than benign groups (p < 0.001), and in telomerase positive than telomerase negative patients (p < 0.001). In malignant group, mean rank of TPS was significantly higher in late stages (p < 0.002), in higher grade (p < 0.05), in larger tumor size (p < 0.01), and in lymph node positive patients (p < 0.001). ROC curve was utilized to choose the best cutoff for serum TPS (88 U/L). At this cutoff, the sensitivity was 95%, and the specificity was 75%. At a higher cutoff (109 U/L), TPS positivity was significantly correlated to stage, grade, lymph node status, and telomerase positivity (p < 0.05).

CONCLUSION

Telomerase positivity and serum TPS might be used as additional markers for assessment of breast cancer.

Deletion of p16 and p15 genes In schistosomiasis-associated bladder cancer (SABC)

Alterations of p16 and p15 genes have been reported in cancer cell lines and in certain malignant neoplasm. These genes are designated as candidate tumor suppressor genes because they encode proteins that function as negative cell cycle regulators at G(1)-S checkpoint. One hundred and sixty eight tumor tissue, 20 schistosomal tissue, and 50 normal tissue samples were examined. The status of p16 and p15 genes in these tissues was determined by the polymerase chain reaction and by sequencing the DNA fragments produced during PCR. In addition, the expression of p16 and p15 proteins was examined by Western blot analysis. p16 and p15 genes were detected in all normal and schistosomal tissues. Deletion of both p16 and p15 genes was observed in 72 and 36 bladder tumors, respectively. Twenty eight of the 72 cases that exhibited p16 deletions also displayed deletions of p15. Only eight cases showed loss of the p15 gene while retaining p16 gene, and p16 deletion with apparently intact p15 gene was identified in 44 cases. The present analysis also reveals that deletion in the two genes are associated with low-stage, low grade bladder cancer, schistosomiasis-associated bladder cancer (SABC) and squamous cell carcinoma type (SCC). No point mutations were identified in either gene. The expression of p16 and p15 proteins was undetectable in 75 and 38 bladder tumors, respectively, by Western blot analysis. Alteration of the p16 and p15 genes appears to be an early event in bladder cancer which occurs more frequently in SABC and SCC, and may play an important role in the development of schistosomal bladder cancer.

Immunohistochemical expression of p53 and c-erbB2 proteins in breast cancer in Egypt

The purpose of the present study was to estimate p53 and c-erbB2 expression in an Egyptian cohort and assess their relationships with other indicators of aggressive disease. Additionally, the frequency of both oncogenes was compared to that reported in other breast cancer populations. Paraffin-embedded tissue sections obtained from 210 invasive ductal carcinomas were evaluated immunohistochemically for p53 and c-erbB2 oncoproteins using CM-1 polyclonal antibody and mAb1 monoclonal antibody, respectively. Tumor proliferation was also assessed using PC10 anti-PCNA (proliferation cell nuclear antigen) monoclonal antibody. Chi square test was used to assess the relationship between p53 and c-erbB2 and their associations with other prognostic factors. The results revealed that p53 and c-erbB2 were equally expressed, each accounting for 40% of the total cases (84 out of 210) Immunoreaction for p53 and/or c-erbB2 was demonstrated in 65% (136 out of 210) and 15% (32 out of 210) were positive for both oncogenes. Poor histologic grade was more significantly associated with p53 expression (P = 0.0001) than c-erbB2 expression (P = 0.01). The latter was also significantly associated with premenopausal status (P = 0.01) and large tumor size (P = 0.003). Both p53 and c-erbB2 oncoproteins were found to be unrelated to each other, nodal status or PCNA immunostaining. These data suggest that p53 and c-erbB2 oncogenes correlate with poor prognostic features of breast cancer. The differences between the frequency of p53 and c-erbB2 expression observed in this study and in the reports of Western authors will hopefully stimulate investigation of these oncogenes using molecular biologic techniques and matched comparative Egyptian and European breast cancer groups.

Estimation of glutathione S-transferase and its Pi isoenzyme in tumor tissues and sera of patients with ovarian cancer

OBJECTIVES

The Pi class GST is the most ubiquitous of the human GST family, being expressed in different tissues. However, its role in ovarian cancer is still poorly defined. To establish normal and tumor related changes, the levels of total GST as well as its isoenzyme GST Pi, were therefore measured in ovarian tissue samples and the corresponding serum specimens obtained from patients undergoing primary surgical treatment for their disease (n = 68). The total GST activity was spectrophotometrically determined utilizing 1-Chloro- 2,4-dinitrobenzene (CDNB) as the substrate. The GST Pi isoenzyme was measured by ELISA and immunohistochemical methods.

RESULTS

The total GST activity, the level of GST Pi isoenzyme, the DNA content and S phase fraction were significantly higher in the malignant than in non-malignant ovarian tissues. In the malignant group the values of both cytosolic total GST and GST Pi were significantly correlated (r = 0.56, P = < 0.01). In spite of the absence of a significant correlation with a number of important prognostic features including the patient age, FlGO stage, DNA content and S-phase fraction, both total GST and GST Pi were significantly higher in the grade I than in grades II and III malignant tumors. Additionally, the total GST was significantly lower in the serous than non-serous malignant tumors.

CONCLUSION

In the malignant group, although the elevation of blood content of GST and its Pi isoenzyme was not as significant as that of the tissue content, the fact that higher serum values of patients with some cancers often reverted to the normal range after treatment of the cancer suggested the direct derivation of these enzymes from tumor tissues. Thus, follow up of elevated serum GST and GST Pi levels may be useful for monitoring ovarian cancer patients during the course of treatment.

Ovarian cancer-induced immunosuppression: relationship to tumor necrosis factor-alpha (TNF-alpha) release from ovarian tissue

Cytokines have been reported to be potential biological markers of, disease status in cancer patients. Tumor necrosis factor-alpha (TNF-alpha) is a key cytokine released from monocytes and macrophages. TNF-alpha is involved in essential biological functions such as immunoregulation, modulation of cell growth and differentiation. In this work, the role of TNF-alpha release in ovarian cancer patients was investigated. Fifty-five patients with ovarian cancer and 20 controls of matched age and parity were included in this study. TNF-alpha concentrations were measured in sera and cytosolic fractions of both groups. The results demonstrated a significant increase in TNF-alpha concentrations among patients compared to the control subjects (P < 0.001). Furthermore, a non-significant increase (P = 0.05, was observed between the different types (serous, Mucinous, and endometrioid) of epithelial ovarian cancers. Also TNF-alpha concentrations did not correlate with the disease stage. Moreover, immunohistochemical analysis of tissue specimens stained for TNF-alpha was positive in malignant lesions and negative for the normal ovarian tissue. These findings confirmed the TNF-alpha kinetics obtained by ELISA assays. Interestingly, TNF-alpha levels were also elevated in culture supernatants of PBMC stimulated by cytosolic fractions from malignant ovarian tissues. Blastogenic assays using cytosolic fractions from malignant ovarian specimens to stimulate healthy donor peripheral blood mononuclear cells (PBMC) showed a marked decrease in 3H-thymidine uptake compared to the cells stimulated by normal cytosols. To establish a cause-effect relationship between TNF-alpha release and inhibition of cell proliferation, the experiments showed that 3H-thymidine uptake by PBMC was markedly inhibited by recombinant human TNF-alpha (rh TNF-alpha) and that inhibition was significantly reversed when TNF-alpha monoclonal antibody was added to the cells. The data presented in this work indicate that TNF-alpha may play an important role in the biology of ovarian cancer and hence, tumor pathogenesis.

Determination of cytosolic citrulline and nitrate as indicators of nitric oxide in bladder cancer: possible association with basic fibroblast growth factor

BACKGROUND

Nitric Oxide (NO) and nitrosamines have been implicated in bladder carcinogenesis. Apart from its implication in carcinogenesis, NO contributes to the regulation of tumor angiogenesis via angiogenic peptides exemplified by basic fibroblast growth factor (bFGF).

OBJECTIVES AND METHODS

In order to examine NO pattern in normal, schistosomal, and malignant bladder cytosols, we have used a combined approach by measuring nitrate and the amino acid citrulline. The results were correlated to bFGF, which were measured in bladder cytosols by an EIA method.

RESULTS

Comparison between normal, schistosomal, and malignant bladder groups showed that patients with schistosomiasis and bladder cancer had significantly higher cytosolic nitrate, citrulline, and bFGF levels. There were no apparent correlations between these investigated parameters and tumor histologic features. The level of citrulline was strongly correlated to nitrate level and both were correlated to bFGF level in bladder cancer and schistosomiasis groups.

CONCLUSIONS

Our findings indicate that NO and bFGF were significantly elevated in schistosomiasis and bladder cancer compared to normal bladders. Moreover, the consistent association of NO with bFGF found in the present work, support the hypothesis that the angiogenic peptide bFGF may be modulated by NO and suggest a useful target in antiangiogenic therapy in bladder cancer.

Cis-platinum-induced immunosuppression: relationship to melatonin in human peripheral blood mononuclear cells

OBJECTIVES

The purpose of this study was to investigate the immunomodulatory effect of melatonin (MLT) on human peripheral blood mononuclear cells (PBMC) and to address its effects on Cis-platinum (CDDP)-induced cytotoxicity.

METHODS AND RESULTS

The obtained data from this study revealed that treatment of cells with MLT (100 microg/ml) for 24 h enhanced cell viability. When cells were exposed to CDDP (5 microg/ml), cell proliferation in response to phytohaemagglutinin (PHA) stimulation was reduced by 49.63% compared to control cells as detected by 3[H]-thymidine uptake. Furthermore, Cis-platinum significantly depleted intracellular glutathione (GSH) levels by approximately 47% below that of untreated cells and led to apoptotic changes in the target cells as evidenced by DNA fragmentation (45% compared to 5% in control cells as measured by diphenylamine assay). DNA fragmentation was also confirmed by agarose gel electrophoresis. However, MLT enhanced cell proliferation by approximately 8.63% above the control values, and counteracted the antiproliferative effect of CDDP. The GSH levels were significantly increased in response to MLT (71% above control values) and it protected the cells against GSH depletion induced by CDDP. Moreover, DNA fragmentation and laddering produced by CDDP were significantly reduced or even disappeared when the cells were pretreated with MLT or the latter was simultaneously added with CDDP.

CONCLUSIONS

The findings from this study indicated that melatonin is a potent immunomodulatory hormone that protects PBMC against cis-platinum-induced immunosuppressive effects. These effects might improve the patients' response to cis-platinum therapy and, therefore, their survival rates.

Evaluation of some tissue and serum biomarkers in prostatic carcinoma among Egyptian males

OBJECTIVES

The purpose of this study is to evaluate the role of soluble E-cadherin as a serum marker and bcl-2 and DNA content as tissue markers in characterization and management of prostatic adenocarcinoma (PC) among Egyptian males.

DESIGN AND METHODS

The study group included 71 patients with prostatic adenocarcinoma, 30 patients with benign prostatic hyperplasia (BPH), and 20 normal male subjects. Serum soluble E-cadherin (sE-cadherin) and PSA were quantified by ELISA and MEIA (microparticle enzyme immunoassay) techniques, respectively. Tissue samples were investigated for bcl-2 chromosomal translocation t(14;18) by polymerase chain reaction (PCR) together with detection of bcl-2 protein expression by immunohistochemistry. The results were correlated with DNA content (as defined by flow cytometric analysis) and also with traditional clinicopathologic parameters.

RESULTS

Our data revealed that, serum PSA was superior to sE-cadherin as a marker for PC with a sensitivity of 83% compared to 59% in case of E-cadherin at the same specificity (96.6%). Combination of both markers raised the sensitivity to 90%. E-cadherin correlated with Gleason score. Ploidy status, synthetic phase fraction (SPF), and proliferation index (PI) correlated significantly with tumor Gleason score. PI was also correlated to clinical stage. bcl-2 protein was overexpressed in 14% of PC and it showed a trend for correlation with tumor Gleason score (p = 0.06). We failed to detect chromosomal t(14;18) in the bcl-2 gene in all the studied tumors.

CONCLUSIONS

E-Cadherin is a clinically useful biomarker in PC specially in combination with PSA. DNA content changes and bcl-2 oncogene may account for tumorogenesis and may assist in prognostication of PC.

Correlation between EBV DNA and rearrangement and expression of Bcl-2 gene in aggressive non-Hodgkin's lymphoma

Previous in vitro studies have shown that bcl-2 expression can be induced by transfection of Epstein-Barr virus (EBV)-negative non-Hodgkin's lymphoma (NHL) cell lines with EBV. This induced expression of bcl-2 is important for the long survival of EBV-positive cells and might be a first step in tumorigenesis. The purpose of the present study was to investigate the possibility of similar correlation between bcl-2 expression and EBV infection in vivo in a cohort of patients with aggressive NHL, who were uniformly evaluated and treated with effective chemotherapy. The 42 patients included were 25-65 years old. None had prior treatment, discordant lymphoma, or human immunodeficiency virus seropositivity. Fresh biopsied samples were obtained and stored frozen for analysis of bcl-2 gene rearrangement major break point and of EBV DNA by PCR. Bcl-2 protein expression was estimated by Western blot, and enzyme immunoassay. With a median follow-up of 30 months, overall survival (OS) and disease-free survival (DFS) were measured to determine the prognostic significance of these variables. Analyzable DNA was present in all samples, 24% demonstrating bcl-2 rearrangement and 33% showing EBV DNA. Patients with bcl-2 gene rearrangement tended to have shorter DFS, and OS than patients without translocation. Bcl-2 protein expression was not correlated to gene rearrangement and had no significant influence on survival. The presence of EBV DNA in NHL had no prognostic significance but was correlated to bcl-2 expression. EBV-positive tumors showed higher bcl-2 expression than EBV-negative tumors did. Our results suggest a role of EBV infection in inducing bcl-2 expression as a survival factor for EBV-positive cells.

Increased bcl-2 expression is associated with primary resistance to chemotherapy in human epithelial ovarian cancer

OBJECTIVE

bcl-2, an anti-apoptotic factor, has a role in the pathogenesis of ovarian cancer as well as in resistance to chemotherapy.

DESIGN AND METHODS

20 benign, and 26 malignant epithelial ovarian tissues were analyzed for bcl-2 protein and mutant p53 by enzyme-immunoassay (EIA). Flowcytometric analysis was also performed. Patients of malignant group were followed up to monitor overall survival and primary resistance to chemotherapy.

RESULTS

bcl-2 was significantly higher in malignant group than benign group (p < 0.001). A cutoff value was determined for bcl-2 (63.8 kU/g protein). At this cutoff, sensitivity is 80.7%, and specificity is 85%. Using chi square analysis, a significant correlation was found between bcl-2 and FIGO stage (p = 0.01), overall survival (p = 0.01), as well as primary resistance to chemotherapy (p = 0.03). By correlation coefficient analysis the relation between bcl-2 and synthetic phase fraction was highly significant (p = 0.002). Bcl-2, p53, and FIGO stage were significantly correlated to poor survival (p = 0.01) in univariate analysis. However, in multivariate analysis, only FIGO stage, and p53 were independent risk factors.

CONCLUSION

EIA could be a useful tool for investigating the prognostic value of bcl-2, and its possible prediction of platinum resistance in epithelial ovarian cancer. This might help in selecting patients for future anti-bcl-2 therapy.

Expression of p21WAF1/CIP1 in bladder cancer: relation to schistosomiasis

Cell cycle regulation is mediated in part through expression of the cyclin-dependent kinase inhibitor p21WAF1/CIP1. Loss of p21WAF1/CIP1 expression may, therefore, contribute partially to schistosomal carcinogenesis in the urinary bladder. We compared p21WAF1/CIP1 expression in schistosomal and nonschistosomal bladder cancer to explore possible differences in p21WAF1/CIP1 expression between the two subtypes and the possible association between schistosomiasis and loss of p21WAF1/CIP1 expression. Tumor specimens were obtained from 130 patients who underwent transurethral biopsy or cystectomy. p21WAF1/CIP1 was determined by immunodot blot, Western blot, and enzyme immunoassay (EIA). We validated a highly sensitive quantitative EIA assay for determination of p21WAF1/CIP1 in cell lysates. Precision, analytical recovery, and linearity were all excellent. Our results did not show any correlation between p21WAF1/CIP1 expression and most clinicopathologic variables. Lower expression of p21WAF1/CIP1 was evident in squamous cell carcinoma (SCC) and schistosomal subtype than in transitional cell carcinoma and nonschistosomal tumors. Our data suggest a potential role for p21WAF1/CIP1 alteration in schistosomal carcinogenesis.

Regulators of apoptosis in human breast cancer

OBJECTIVES

Apoptosis or programmed cell death represents a mechanism by which tumor cells with DNA damage can be deleted. Bcl-2 and p53 gene products have been both linked to apoptosis. Bcl-2 plays a role as an inhibitor of apoptosis that may extend the viability of cells containing genetic alterations and facilitate tumor progression. Mutant p53 has a similar effect. The purpose of this study was to investigate expression of bcl-2 in 70 malignant and 30 benign breast lesions using different methods (enzyme immunoassay, immunodot blot, Western blot) and to compare it with the established clinicopathological prognostic factors (age, tumor size, type, grade, lymph node status) and some molecular genetic markers in breast cancer.

RESULTS

bcl-2 and mutant p53 were highly expressed in breast cancer than benign breast lesions and aneuploidy was more frequently detected in malignant breast samples. No correlation could be observed between bcl-2 expression and node status, tumor size, differentiation, type, age at excision or mutant p53 expression. However, a strong positive associations were seen between bcl-2 and estrogen receptors (ER), DNA aneuploidy. Eighty-five percent of bcl-2 positive tumors were ER positive and 65% were aneuploid, while in bcl-2 negative tumors only 28% were ER positive and 37% were aneuploid.

CONCLUSIONS

The association seen between bcl-2 and ER raises the possibility that bcl-2 is an ER-regulated gene which suggests a potential important role for bcl-2 as a modulator of response to hormonal therapy in breast cancer. Monitoring hormonal therapy can easily be done by bcl-2 quantitative EIA method.

Differential tumor markers and hepatitis markers profile in liver tumors

The differential diagnostic utility of AFP, CEA, CA19.9 and TPA was evaluated in liver tumors. They were determined in the sera of 61 patients with primary hepatocellular carcinoma (HCC), 18 with secondary liver metastasis, 61 of benign liver cirrhosis in comparison to 20 normal healthy control subjects. The association of either HBV or HCV infection and HCC was also studied through the assay of HbSAg, HbSAb, and HCV-Ab. The optimal cut-off values were determined using the diagnostic accuracy measurements and the receiver operating characteristic (ROC) curves. AFP at an optimal cut-off value of 100 ng/ml and TPA at 160 U/L showed the highest sensitivity and specificity in detecting liver metastasis (100% and 87% for AFP; 100% and 54% for TPA respectively). The obtained data indicated that the combined assay of AFP and TPA resulted in a better discrimination of HCC among patients with hepatic focal lesions. HCV-Ab was detected in a higher ratio of HCC patients (83.6%) compared to HbsAg (68.9%), and both were detected in (34%) of HCC patients. This high incidence of HCV-Ab may suggest the implication of HCV in the molecular events leading to hepatic carcinogenesis.

Flow cytometric analysis of estrogen receptor expression in isolated nuclei and cells from mammary cancer tissues

BACKGROUND

Cellular expression of receptors for the hormones estrogen and progesterone in human mammary tumors is of diagnostic and prognostic value. Ligand binding assays have been replaced by immunohistochemical analysis of receptor expression. However, both of these techniques are slow, and in the ligand-binding assay it is difficult to measure heterogeneity of receptor expression in individual cells. Flow cytometry has been used extensively for monitoring the expression of cellular receptors in hematopoietic tumors but has been of limited value in the analysis of mammary tumors, which are difficult to disaggregate into single cells for flow analysis. Hormone receptors have a predominant nuclear localization, and it is relatively easy to isolate nuclei from paraffin-embedded archival tissues for flow cytometric analysis of receptor expression.

METHODS

Thick sections from formalin-fixed paraffin-embedded archival mammary tumors were digested by different enzyme solutions for the isolation of single nuclei. Different fixatives were used to compare the results on subsequent staining of the nuclei for estrogen receptor (ER) expression. Double staining with propidium iodide and fluorescein isothiocyanate labeled secondary antibodies for ER expression was used for multiparametric analysis of ER and DNA content.

RESULTS

Digestion of paraffin sections with low concentration of pepsin and detergents was ideal for isolation of single nuclei. Fixation with paraformaldehyde in the presence of Triton X-100 improved staining of the cells. Isolated nuclei had enhanced immunoreactivity compared with the whole cells, and subpopulations differing in reactivity could be identified in the nuclear fractions. Double staining of nuclei for ER expression and DNA content could allow for multiparametric analysis of these two important parameters.

CONCLUSIONS

The procedures described can be used for processing of archival paraffin-embedded mammary tumors for monitoring of ER expression and aneuploidy. These two parameters have important diagnostic and prognostic significance in mammary tumors. Laser flow cytometry by providing multiparametric analysis can allow for correlation of these cellular markers with other important cellular and clinical parameters.

Serum leptin as an additional possible pathogenic factor in polycystic ovary syndrome

OBJECTIVES

Recent data raised the possibility that high leptin levels may contribute to infertility in some women with PCOS.

DESIGN AND METHODS

To assess changes in leptin levels and its relationship to some hormonal changes (insulin, testosterone, SHBG, FSH, LH, and prolactin) associated with PCOS in obese (n = 27) and nonobese (n = 18) patients when compared to obese and nonobese normal controls (n = 20).

RESULTS

Leptin concentration were significantly higher in PCOS than in controls, p < 0.05, with 81% sensitivity and 50% specificity. Whereas, high serum insulin levels were found in obese and nonobese women with PCOS, high serum leptin, FAI together with reduced SHBG were found in obese rather than nonobese PCOS women. Moreover, hyperleptinemia in PCOS women was not correlated to hyperinsulinemia (r = -0.13 and -0.4 in obese and nonobese PCOS women, respectively). In the patient's group correlation analysis between fasting serum leptin and different studied variables showed some correlation with body mass index (BMI) only (r = 0.413) suggesting that high leptin levels could be a characteristic of the obese PCOS. However, multiregression analysis showed that together with testosterone, leptin can successfully predict the presence or absence of PCOS.

CONCLUSION

The potential significance of leptin for the pathophysiology of PCOS will await direct studies of the effects of exogenous leptin and/or its inhibitors on the reproductive axis of women, including those with PCOS.

Assessment of erythropoietin levels and some iron indices in chronic renal failure and liver cirrhosis patients

This study was constructed to investigate the relationship between renal anaemia and erythropoietin (EPO) concentrations in chronic renal failure (CRF) patients and to evaluate the possible role of the liver. Serum EPO levels were measured in blood samples from 20 CRF patients on hemodialysis (HD), 20 liver cirrhosis (LC) patients, 20 patients having both CRF and LC and undergoing HD, and 20 normal control subjects. Blood cell counts, iron indices (iron, total iron-binding capacity (TIBC) and ferritin), renal function (blood urea nitrogen (BUN) and creatinine), hepatic function (ALT, AST, ALP and bilirubin) investigations were carried out for all the subjects enrolled in this study. CRF patients without LC had serum EPO concentration of 6.21 +/- 0.53 mU/ml (mean +/- SE), which was significantly higher than that in patients having both CRF and LC (4.32 +/- 0.52) (p < 0.01). Both groups showed significantly lower values than the controls (12.75 +/- 0.70) (p < 0.001). LC patients with intact kidneys had significantly higher EPO level (22.70 +/- 1.70) (p < 0.001). No correlation was found between EPO level and any of the hematologic or iron indices.

Serum lipoprotein (a) levels in chronic renal failure and liver cirrhosis patients. Relationship with atherosclerosis

This study was carried out to investigate the relationship between lipoprotein (a) levels and the development of atherosclerosis in chronic renal failure (CRF) patients with the possible role of the liver. Serum Lp (a) levels were measured in samples from 20 CRF patients on hemodialysis (HD), 20 liver cirrhosis (LC) patients, 20 patients having both CRF and LC and undergoing HD, and 20 normal control subjects. Renal function (blood urea nitrogen (BUN) and creatinine), hepatic function (transaminases (ALT and AST), alkaline phosphatase (ALP) and total bilirubin) investigations and serum cholesterol were carried out for all the subjects enrolled in this study. Serum Lp (a) concentration in CRF patients without LC was 87.25 +/- 6.17 mg/dl, which was significantly higher than all the investigated groups (P < 0.001). Lp (a) concentration in patients with both CRF and LC was 24.65 +/- 1.98 mg/dl, which was not significantly different from the controls, but was significantly higher than that in the subjects with LC only (P < 0.001) where the latter group had significantly low Lp (a) values (11.1 +/- 0.99) relative to all the other groups (P < 0.001). Lp (a) correlated positively with cholesterol in all groups except the LC subjects, but did not correlate with age, or renal function in both CRF groups.

Therapeutic strategies against epilepsy in Mediterranean countries: a report from an international collaborative survey

A collaborative survey was performed to compare prescribing strategies for the treatment of epilepsy in Mediterranean countries, based on analysis of 500 questionnaires compiled by physicians in 14 different countries. For partial seizures, carbamazepine was the drug of choice in most countries, whereas the second choice of drug differed widely. For primarily generalized tonic-clonic seizures, valproic acid was usually preferred, but other drugs used widely in some countries included phenobarbital, phenytoin and carbamazepine. Lamotrigine was the most popular second-line drug for primarily generalized tonic-clonic seizures in the European countries. In patients where the initial drug failed, switching to an alternative monotherapy was usually the preferred strategy, but advocates of early use of combination therapy exceeded 30% in the respondents of seven countries. Most respondents, in all countries except Turkey, did not prescribe drugs to prevent recurrence of febrile seizures; however, intermittent prophylaxis with a benzodiazepine was advocated by a considerable number of physicians, and continuous prophylaxis was prescribed by a significant minority of respondents in France, Syria and Tunisia. New drugs were rarely used as first-line treatment due to high cost and inadequate experience. Overall, this survey indicates that there is a wide variability in therapeutic practices between and within countries. This information may be useful for the implementation of national educational activities and for the design of pragmatic trials aimed at comparing different therapeutic strategies.

Stapedectomy for far-advanced otosclerosis

Patients with far-advanced otosclerosis (FAO) may appear to be suffering from profound sensorineural hearing loss and are frequently directed to cochlear implantation programmes. In order to avoid such misdiagnosis, FAO should be considered in patients with non-measurable bone-conduction levels and air-conduction levels exceeding 85 dB. Specific clues can lead the clinician to suspect otosclerosis as the aetiology of hearing loss. A review of eight patients (nine ears) with FAO who underwent stapedectomy from 1985-1995 reveals that six of the eight (75 per cent) who had been unable to use a hearing aid preoperatively obtained serviceable hearing with a hearing aid after surgery. This confirms that cochlear implantation is not the best treatment for all profoundly deaf patients; some are better off with stapedectomy.

Comparison of flow cytometric DNA content analysis in fresh and paraffin-embedded ovarian neoplasms: a prospective study

DNA ploidy analysis was performed on both fresh and paraffin-embedded preparations from each of 54 malignant ovarian neoplasms. Aneuploidy was detected in both the fresh and the paraffin-embedded tissue in 19 out of 54 (35%) malignant cases. In addition, aneuploidy was detected exclusively in fresh tissue in seven of the malignant cases, and exclusively in paraffin-embedded tissue in one of the malignant cases, yielding a total of 27 out of 54 (50%) aneuploid cases. The correlation coefficient (r-value) for fresh and paraffin-embedded tissue ploidy analysis in the malignant specimens was 0.91. Although the frequency of recurrence was higher and overall survival lower in the malignant aneuploid specimens of both types, the combined analysis of DNA and survival rates indicated superior prognostic significance of fresh tissue. Of the seven patients in whose specimens aneuploidy was detected exclusively in fresh tissue, all died of recurrent disease during the follow-up period. Our finding indicates that data generated by flow cytometry analysis of formalin-fixed tissue should be interpreted with caution before the data can be used to draw clinical inferences.

The value of CA 125 and CA72-4 in management of patients with epithelial ovarian cancer

The role of the tumor markers CA125 and CA72-4 has been evaluated in the diagnosis and management of ovarian cancer. Both markers were measured in 30 patients with proven epithelial ovarian cancer, 30 patients with benign pelvic masses and 30 normal women. CA125 and CA72-4 were measured using the luminometric immunoassay and immunoradiometric assay respectively. All patients with ovarian cancer were submitted to surgical staging and cytoreduction followed by adjuvant platinum based chemotherapy for 3-6 courses. Fixing the specificity at 95%, CA125 had a sensitivity of 76.7% at a cut-off 85 u/ml while CA72-4 had a sensitivity of 70% at a cut-off 8.5 u/ml. The combination of CA72-4 with CA125 increased the sensitivity to 95% while fixing the specificity at 95%. Among seven cases with stage I and II ovarian cancer five cases had CA125 level below 85 U/ml, three patients out of them had CA72-4 above 8.5 U/ml. CA 72-4 could reflect the residual disease following cytoreduction and could improve the detection of relapse by CA125.

CONCLUSION

CA72-4 could complement the standard tumor marker CA125 both in diagnosis and follow up of patients with epithelial ovarian cancer.

Epstein-Barr virus, human papillomavirus, and flow cytometric cell cycle kinetics in nasopharyngeal carcinoma and inverted papilloma among Egyptian patients

It is widely accepted that the Epstein-Barr virus is etiologically associated with the development of nasopharyngeal carcinoma. The human papillomavirus is also associated with inverted papilloma. We used the polymerase chain reaction technique to detect both viruses in both types of tumors. Flow cytometry was also used to study the DNA pattern and proliferative behavior of the tumors in relation to the viruses. EBV was detected in 13/20 (65%) of NPC specimens, and in none of IP (n = 10) or control specimens (n = 10). This indicates the contribution of EBV as an etiologic factor in NPC. Five cases of NPC (25%) were positive for HPV 16, two of them were EBV positive. Four HPV 16 positive cases were found among cases with inverted papilloma, but none among the control cases. Flow cytometry revealed that all NPC, IP, and control samples were diploid except one aneuploid NPC sample. Proliferative capacity (PC) of primary tumors was predictive of tumor recurrence in NPC. Using 13.6% as a cut-off point for PC, we were able to discriminate between high risk and low risk groups with 100% sensitivity and 86% specificity. PC can be used as a baseline prognostic parameter in NPC, making it possible to modify courses of treatment in an attempt to inhibit tumor recurrence.

Multivariate analysis of DNA ploidy, p53, c-erbB-2 proteins, EGFR, and steroid hormone receptors for short-term prognosis in breast cancer

BACKGROUND

Several molecular-genetic alterations in breast cancer, including aneuploidy, aberrant expression of p53, c-erbB-2, and EGFR have been associated with poor prognosis in breast cancer particularly in lymph node negative patients. To determine the importance of molecular-genetic factors relative to more traditional surgical-pathologic prognostic factors, a multivariate analysis was performed particularly in lymph node positive breast cancer cases.

METHODS

One hundred fresh samples of primary breast carcinoma have been studied with flow cytometry for DNA ploidy. On the same specimens steroid hormone receptors (ER and PR) were measured in cytosol fraction using Abbott ELIZA assays, c-erbB-2 and EGFR were determined in the tissue homogenate and mutant p53 protein in the nuclear fraction by Oncogene Science ELISA procedures. In addition, information regarding surgical-pathologic features of the tumor was obtained. Multivariate analysis using Cox's proportional hazards model was done to identify variables predictive of poor prognosis.

RESULTS

With univariate analysis, tumor size, lymphnode number, p53, c-erbB-2 were predictive of poor short term prognosis. In the multivariate analysis, only c-erbB-2 (P = 0.001) and p53 (P = 0.05) were significant. Subgroup analysis by nodal status yielded significant association of c-erbB-2 (P = 0.001) and p53 (P = 0.04) with lymph node positive breast cancer.

CONCLUSIONS

Among molecular-genetic prognostic factors, c-erbB-2 was the most strongly predictive of poor short term prognosis followed by p53 in lymph node positive breast cancer.

Multivariate analysis of DNA ploidy, p53, c-erbB-2 proteins, EGFR, and steroid hormone receptors for prediction of poor short term prognosis in breast cancer

BACKGROUND

Several molecular-genetic alterations in breast cancer, including aneuploidy, aberrant expression of p53, c-erbB-2 and EGFR, have been associated with poor prognosis in breast cancer patients particularly those who are lymph node negative. To determine the importance of molecular-genetic factors relative to more traditional surgical-pathologic prognostic factors, multivariate analysis was performed on lymph node positive breast cancer cases.

METHODS

One hundred fresh samples of primary breast carcinoma were studied with flow cytometry for DNA ploidy. On the same specimens steroid hormone receptors (ER and PR) were measured in the cytosol fraction using Abbott ELIZA assays, c-erbB-2 and EGFR were determined in the membrane fraction and mutant p53 protein in the nuclear fraction by Oncogene Science ELISA procedures. In addition, information regarding surgical-pathologic features of the tumor was obtained. Multivariate analysis using Cox's proportional hazards model was done to identify variables predictive of poor prognosis.

RESULTS

Using univariate analysis, tumor size, lymph node number, p53, c-erbB-2 were predictive of poor short term prognosis. By multivariate analysis, only c-erbB-2 (P = 0.001) and p53 (P = 0.05) were significant. Subsgroup analysis by nodal status yields a significant association of c-erbB-2 (P = 0.001) and p53 (P = 0.04) with lymph node positive breast cancer.

CONCLUSIONS

Among molecular-genetic prognostic factors, c-erbB-2 was the most strongly predictive of poor short term prognosis followed by p53 in lymph node positive breast cancer.

DNA ploidy in hepatic cirrhosis, dysplasia and carcinoma

Hepatocellular carcinoma (HCC) is the most common and aggressive form of primary liver tumors. The evolution and the putative association of this neoplasm with hepatic cirrhosis and liver cell dysplasia remain uncertain. We analyzed the DNA ploidy by flow cytometry in a cohort of 130 liver specimens representing liver cirrhosis, hepatic cell dysplasia and hepatocellular carcinoma to determine the incidence and potential biological relevance of this feature. Our results show that four (8.0%) of the 50 cirrhotic lesions, four (26.7%) of 15 dysplastic, and 51 (78.5%) of the 65 HCC manifested DNA aneuploidy. Moreover, DNA aneuploidy was manifested in 60% of histologically negative hepatic resection margins of HCC. Our results indicate that: i) the presence of DNA aneuploidy in some cirrhotic livers and liver cell dysplasias support the potential evolution of HCC from a subset of these lesions that harbor such clonal alterations, ii) DNA aneuploidy in histologically negative resection margins of HCC in some cases support the concept of field cancerization in these tumors and iii) the predominance of DNA aneuploidy and high proliferative index (PI) in liver cell carcinomas underscore their aggressive biological behavior.

Liposomal distribution in malignant glioma: possibilities for therapy

We investigated the potential of 111In-labelled liposomes to specifically target recurrent high-grade glioma in eight patients, all of whom had clinical and radiological evidence of relapse following prior treatment with surgery and radiotherapy. The phospholipid liposomes were labelled with 74 MBq 111In and injected intravenously. The distribution of radioactive material in the brain was imaged using a dedicated neuro-SPET imager. Images were taken 1 h post-injection and repeated at 24, 48 and 72 h. In addition, whole-body images were performed with a gamma camera and blood taken for radioactivity determination. At 72 h post-injection, excellent tumour demarcation could be seen in seven of eight patients. The images obtained correlated well with the corresponding computed tomography images. Blood radioactivity levels gradually declined over the 72 h. Tumour uptake continued to rise throughout this time and, together with the steady fall in normal brain tissue, the tumour-to-brain contrast gradually increased (maximum 7:5). Whole-body images indicate that the liver is the major organ of uptake with up to 50% of the injected dose. No toxicity could be attributed to the injected liposomes. Although the total percentage uptake was low (1.1%), the tumour-to-brain contrast ratios, together with the SPET images, suggest the potential for tumour-specific targeting.

Immunohistochemical markers of tumor prognosis in breast cancer in Egypt

Although the relationship among different biologic markers of breast cancer has been shown to be important in predicting cancer behavior, expression of these markers can be an attribute of the population under study. Breast cancer is the most common malignancy among Egyptian women. We have studied a number of prognostic tumor markers in infiltrating ductal carcinoma in a group of Egyptian women and have correlated our results with traditional histologic parameters of behavior such as tumor nuclear grade and lymph node status. Seventy-five cases of infiltrating ductal breast cancer were evaluated from pathology archives. Formalin-fixed paraffin-embedded sections were immunohistochemically stained for PCNA, p53, c-erB-2, metallothionein, cathepsin-D, and GST-pi using specific antibodies and a standard avidin-biotin method. Most high-grade tumors were associated with higher PCNA expression and p53 abnormality. There was a significant difference between node-negative and node-positive tumors with regard to their metallothionein content; other markers, however, did not differ significantly between node-negative and node-positive tumors. PCNA expression, metallothionein expression, and p53 mutation appear to be markers of aggressive tumor behavior in Egyptian women with breast cancer.

Progressive familial intrahepatic cholestasis (Byler's disease) in Arab children

The clinical, biochemical and histological characteristics in six Arab children with progressive familial intrahepatic cholestasis (PFIC) (Byler's disease) are described. The autosomal recessive mode of inheritance is established. Jaundice and pruritus were early symptoms, with onset in the 1st 3 months in all patients. Other features included growth failure, developmental delay, ataxia, areflexia, gall-stones and epistaxis. Gamma-glutamyl-transpeptidase and cholesterol were normal, but total bile acid levels were uniformly elevated in all patients. Histology showed features of hepato-canalicular cholestasis, lack of bile duct proliferation and fibrosis or cirrhosis in all patients. Five patients who were followed up were alive at a mean age of 75.8 months.

Multivariate analysis of DNA ploidy, steroid hormone receptors, and CA 125 as prognostic factors in ovarian carcinoma: a prospective study

The prognosis in ovarian cancer patients remains poor, and there is a need to identify patients who are less likely to respond to treatment. In a prospective study of patients with ovarian carcinoma treated by a standard protocol, variables such as age, tumor type, International Federation of Gynecology and Obstetrics stage, histologic grade, results from flow cytometry, receptors for estrogen (ER) and progesterone (PR), and serum CA 125 were correlated to relapse and survival. Univariate analysis revealed that stage, histologic grade, DNA ploidy, ER, PR, and CA 125 were of significant association to survival, but only stage, DNA ploidy, PR, and CA 125 were found to be of significant value to relapse. Multivariate analysis identified DNA ploidy as an independent prognostic variable for both relapse and survival.

p53 and c-erbB-2 expression in schistosomal urinary bladder carcinomas and schistosomal cystitis with premalignant lesions

Immunoreactivity for p53 and c-erbB-2 proteins was studied in 31 schistosomal urinary bladder carcinomas and 21 cases of schistosomal cystitis with hyperplastic, metaplastic and/or dysplastic (premalignant) lesions. The results were compared with 30 carcinomas and 21 premalignant lesions of the urinary bladder without schistosomiasis. Abnormal nuclear p53 protein accumulation was found in 17/31 schistosomal and in 15/30 non-schistosomal carcinomas and in 8/21 schistosomal cystitis with premalignant lesions of which five showed hyperplasia. No case of non-schistosomal hyperplasia or squamous metaplasia examined showed p53-positivity. In non-schistosomal carcinomas p53 positivity was significantly associated with tumour grade (grade I-II vs grade III tumours: P = 0.021) and greater age (P = 0.004) while in schistosomal carcinomas no such associations were found. Cytoplasmic membrane-bound positivity for c-erbB-2 oncoprotein was found in comparable percentages in schistosomal and non-schistosomal bladder carcinomas (10%), and in both groups was co-expressed with p53. p53 gene alteration is an important event in the development of both schistosomal and non-schistosomal bladder carcinoma.

Parathyroid hormone (PTH) stimulates adrenocorticotropin release in AtT-20 cells stably expressing a common receptor for PTH and PTH-related peptide

Complementary DNA encoding a rat bone PTH/PTHrP receptor was stably expressed in the murine corticotroph cell line, AtT-20. Several clones, expressing variable numbers of PTH/PTHrP receptors, were developed. In contrast to the relatively low binding affinity (apparent Kd = 15 nM) observed in COS-7 cells transiently expressing the PTH/PTHrP receptor, all AtT-20 stable transfectants bound [Nle8,18,Tyr34]bPTH(1-34)NH2 (NlePTH) with an affinity that was indistinguishable from that observed in ROS 17/2.8 cells expressing native PTH/PTHrP receptors. Additionally, NlePTH dramatically increased cAMP accumulation and ACTH release in AtT-20 cells expressing the PTH/PTHrP receptor with an ED50 of 0.6 +/- 0.3 and 0.3 +/- 0.1 nM, respectively. The high binding affinity and the high efficacy of NlePTH in stimulating cAMP accumulation and ACTH release indicate that the PTH/PTHrP receptor is efficiently coupled to the intracellular signalling system responsible for stimulation of ACTH release in AtT-20 cells. No additivity of cAMP accumulation or of ACTH release was observed when these cells were treated with maximally active concentrations of both NlePTH and CRF. This suggests that the receptors for both of these hormones share the same intracellular effectors, and that intracellular signaling in AtT-20 cells is not compartmentalized. Additionally, the ability of NlePTH to stimulate ACTH release in AtT-20 cells, a function that is normally performed by CRF, demonstrates promiscuity between activated receptors and distal biological functions.

Evaluation of gastric carcinoembryonic antigen in endemic schistosomal hepatosplenomegaly

In endemic hepatosplenomegaly with histopathologically proved atrophic gastritis, the gastric juice carcinoembryonic antigen (CEA) showed significant increase. Comparing this group of patients with histopathologically proved gastric neoplasia the levels were significantly higher in the later group. The level of (CEA) was only increased in 75% of cases with endemic hepatosplenomegaly and atrophic gastritis opposite to 100% of cases with gastric neoplasia. The level of serum (CEA) was also studied in patients and control groups. In patients with endemic hepatosplenomegaly and atrophic gastritis the level was insignificantly higher than the control group and significantly lower than the group with gastric neoplasia.

Concentration of calcitonin in seminal plasma of infertile men

Calcitonin levels in peripheral plasma (8 cases) and seminal fluid (30 cases) were measured by direct Radioimmunoassay (RIA). Their relationship with seminal characteristics, calcium and swelling test were evaluated. Seminal plasma calcitonin averaged 7530 pg/ml which amounts to 142 times higher than that of serum averaging 53 pg/ml. There was no significant difference in the mean seminal plasma concentration of immunoreactive calcitonin (iCT) among normozoospermic, oligozoospermic and azoo-spermic groups. However, there was a significant difference (p less than 0.05) in the seminal plasma mean concentration between high and low motility groups. A significant correlation was found between iCT seminal plasma concentration and percent of motility (p less than 0.05), yet, no correlation was detected between iCT and other seminal characteristics including swelling test (p greater than 0.05). Seminal plasma calcium averaged 175.3 +/- 29.9 mg/L which was 1.75 times higher than that of the serum averaging 100.32 +/- 5 mg/L. No significant difference (p less than 0.05) was obtained between high and low motility groups as regard their calcium seminal plasma levels. A significant correlation was found between seminal plasma concentration of calcium and calcitonin (p less than 0.05), but not with the percent of motility (p less than 0.05). Calcitonin (CT) was present in seminal plasma in higher concentrations than those of serum, indicating its active secretion within the male accessory sex glands. The role of CT in human reproduction needs further elucidation, especially regarding sperm motility.

Effect of diabetes and insulin on rat renal glomerular protocollagen hydroxylase activities

The effect of diabetes and insulin on the activities of both prolyl hydroxylase (trivial name; proline,2-oxoglutarate dioxygenase, EC 1.14.11.2) and lysyl hydroxylase (trivial name; lysine,2-oxoglutarate dioxygenase, EC 1.14.11.4) in isolated rat renal glomeruli was determined. Three groups of experimental animals were used: age-matched controls, streptozotocin-diabetic, and insulin-treated streptozotocin-diabetic. Using 14C-labeled lysine or proline hydroxylase substrate prepared from chick embryo tibiae, glomerular 17 000 X g supernatant enzyme was incubated in a complete hydroxylating system for 60 and 120 min Lysyl hydroxylase activity was significantly increased in diabetic preparations, but prolyl hydroxylase activity did not differ from control. Administration of insulin to streptozotocin-injected animals completely restored glomerular lysyl hydroxylase to normal levels. The results suggest that the specific elevation of lysyl hydroxylase relates to the biochemical changes contributory to diabetic nephropathy, and that insulin may reverse this process.

Glomerular protocollagen lysyl-hydroxylase activity in streptozotocin diabetes

Using [14-C]lysine protocollagen substrate prepared from chick embryo tibiae, lysyl hydroxylase activity was found in the 17 000 times g supernatant and particulate fractions obtained from homogenates of isolated rat renal glomeruli. Specific activities using the latter as an enzyme source were about 20-30% that of the supernatant. [14-C]Hydroxylysine formation was proportional to substrate and enzyme concentration, and to time for up to 120 min of incubation. Omission of alpha-ketoglutarate and ascorbate in the incubational assay markedly depressed activity. Hydroxylation of substrate by supernatant enzyme from streptozotocin diabetic rats was significantly increased over that of normal. In contrast, the activity of supernatant fractions from glomeruli of pancreatectomized, normoglycemic animals did not differ from that of non-operated controls. It is concluded that elevated glomerular lysine hydroxylase activity accompanies the increased glomerular collagen synthesis found in streptozotocin diabetes, and that chronic hyperglycemia may be implicated in these changes.