Analysis of MLH1 and MSH2 expression in ovarian cancer before and after platinum drug-based chemotherapy

Preclinical studies have demonstrated a relationship between DNA mismatch repair (MMR) status and sensitivity to cisplatin and carboplatin. MMR-deficient cells are resistant to both drugs, and selection for cisplatin resistance in vitro is sometimes accompanied by loss of MMR protein expression. We used immunohistochemical staining techniques to investigate hMLH1 and hMSH2 expression in paired ovarian tumor sections from 54 ovarian cancer patients before and after platinum-based therapy. We sought associations between hMLH1 and hMSH2 protein expression and clinical parameters known to be of prognostic significance as well as response to treatment and overall survival. hMLH1 and hMSH2 staining decreased significantly after platinum-based therapy. The percent of malignant cells that stained positive correlated with the intensity of nuclear staining for both proteins; staining for hMLH1 correlated well with staining for hMSH2. Unexpectedly, expression of nuclear hMLH1 correlated negatively with response to treatment. Expression of nuclear hMLH1 and hMSH2 was positively correlated with pretreatment CA125 level, and expression of nuclear hMSH2 was positively correlated with change in CA125 level after treatment. Tumor stage was associated with expression of nuclear hMSH2, and tumor histological subtype was associated with both hMLH1 and hMSH2 staining. No association was found between expression of either protein and overall survival. These results indicate that the tumor is biologically altered after chemotherapy consistent with treatment-induced selection for cells expressing lower hMLH1 and hMSH2 levels. However, immunohistochemical staining for either hMLH1 or hMSH2 was not highly predictive of drug sensitivity as measured by response or survival.

Affinity chromatography on immobilized "biomimetic" ligands. Synthesis, immobilization and chromatographic assessment of an immunoglobulin G-binding ligand

A synthetic bifunctional ligand (22/8) comprising a triazine scaffold substituted with 3-aminophenol (22) and 4-amino-1-naphthol (8) has been designed, synthesised, characterised and immobilized on agarose beads to create a robust, highly selective affinity adsorbent for human immunoglobulin G (IgG). Scatchard analysis of the binding isotherm for IgG on immobilized 22/8 (90 micromol 22/8/g moist weight gel) indicated an affinity constant (Ka) of 1.4 x 10(5) M(-1) and a theoretical maximum capacity of 151.9 mg IgG/g moist weight gel. The adsorbent shows similar selectivity to immobilized protein A and binds IgG from a number of species. An apparent capacity of 51.9 mg human IgG/g moist weight gel was observed under the experimental conditions selected for adsorption. Human IgG was eluted with glycine-HCl buffer with a recovery of 67-69% and a purity of 97.3-99.2%, depending on the pH value of the buffer used for elution. Preparative chromatography of IgG from human plasma showed that under the specified conditions, 94.4% of plasma IgG was adsorbed and 60% subsequently eluted with a purity of 92.5%. The immobilized ligand was able to withstand incubation in 1 M NaOH for 7 days without loss of binding capacity for IgG.

Dietary intake of pesticides: State of Kuwait total diet study

The State of Kuwait conducted a total diet study (TDS) to determine the dietary intakes of selected pesticides. This paper reports the results of this study. A national food consumption survey was performed and core food lists for different population groups were established representing the total diet of the Kuwaiti population. Food items (table-ready) were purchased/prepared and analysed for their contents of organophosphate/organochlorine carbamate, benzimidazole and phenylurea pesticides according to the US FDA Pesticide Analytical Manual (PAM I). Dietary intakes of these pesticides are presented for 19 population groups, which range from infants to elderly adults. The intakes of selected population groups are compared with representative findings from the US FDA/TDS and data published from other countries. In general, the average daily intakes were well below acceptable limits, but higher than those reported from developed countries.

Kuwait's total diet study: dietary intake of organochlorine, carbamate, benzimidazole and phenylurea pesticide residues

The State of Kuwait in cooperation with the U.S. Food and Drug Administration (FDA) conducted a Total Diet Study (TDS) to estimate intakes of pesticide residues by the population. The levels of organochlorine (OC) pesticides, carbamates, benzimidazoles, and phenylureas in the TDS core list are reported here. The TDS core list was established through a national food consumption survey. All food items (140 for the Kuwaiti adult) were prepared as eaten and analyzed for the pesticides mentioned above. The FDA's multiresidue methods in Volume I of the Pesticide Analytical Manual were used in gas, liquid, and gel permeation chromatographic analyses. Only vegetable and fruit samples contained pesticide residues (mg/kg), including the carbamates 1-naphthol (1.4) and 3H-carbofuran (0.94) in carrots; the OC pesticide vinclozolin (0.47), 3H-carbofuran (0.66), and fenuron (0.6) in kiwi fruit; the OC pesticide procymidone (0.32) and carbendazim (0.5) in grapes; 3H-carbofuran (5.0) in apricots; the OC pesticides captan (0.013) and thiabendazole (0.63) in pears; captan (0.035) in plums; and carbendazim (0.4) in mandarin oranges. The levels of 3H-carbofuran found in both apricots and kiwi fruit exceeded the maximum residue limits (MRLs) of the Food and Agriculture Organization/World Health Organization (FAO/WHO) of the United Nations. The daily intakes of pesticides by the different population groups are discussed in light of the FAO/WHO acceptable daily intakes.

Regulation of phenylalanine biosynthesis. Studies on the mechanism of phenylalanine binding and feedback inhibition in the Escherichia coli P-protein

Isothermal titration calorimetry (ITC) and site-directed mutagenesis were used to study the interaction of Phe with (a) the Escherichia coli P-protein, a bifunctional chorismate mutase/prephenate dehydratase that is feedback inhibited by Phe, (b) PDT32, a 32 kDa P-protein fragment (residues 101-386) containing the prephenate dehydratase and regulatory domains, and (c) R12, a C-terminal 12 kDa P-protein fragment (residues 286-386) containing the regulatory domain. DeltaH(total) values for PDT32, which included the heats of Phe binding, conformational change, and dimerization, established that in developing a mechanism for end product feedback inhibition, the P-protein has evolved a ligand recognition domain that exhibits Phe-binding enthalpies comparable to those reported for other full-fledged amino acid receptor proteins. Sequence alignments of R12 with other Phe-binding enzymes identified two highly conserved regions, GALV (residues 309-312) and ESRP (residues 329-332). Site-directed mutagenesis and ITC established that changes in the GALV and ESRP regions affected Phe binding and feedback inhibition to different extents. Mutagenesis further showed that C374 was essential for feedback inhibition, but not for Phe binding, while W338 was involved in Phe binding, but not in the Phe-induced conformational change required for feedback inhibition.

The inflammatory and cytotoxic effects of a nitric oxide releasing cream on normal skin

We describe the pro-inflammatory and cytotoxic effects of nitric oxide in vivo in human skin. Nitrite and ascorbic acid were mixed on the skin of 12 normal volunteers, three times daily, to release nitric oxide. Exposure to nitric oxide was varied by randomizing the concentration of nitrite and duration of application. Nitric oxide treated skin showed significant increases in cells expressing CD3, CD4, CD8, CD68, neutrophil elastase, ICAM-1, VCAM-1, nitrosotyrosine, p53, and apoptotic cells compared with skin treated with ascorbic acid alone. There was no significant increase in mast cells. Following application of nitric oxide there were significantly fewer CD1a positive Langerhans cells in the epidermis. These appeared to lose dendritic morphology and migrate from the epidermis. There was no significant difference in staining for Ki-67, a marker related to proliferating cell nuclear antigen, between active and control skin but staining was greater after exposure to higher dose nitric oxide than the low dose. Apoptosis, cytotoxicity, and p53 staining were relatively greater after 48 h exposure than after 24 h. These results suggest that nitric oxide is pro-inflammatory and is toxic to DNA, leading to the accumulation of p53 and subsequent apoptosis. High-dose nitric oxide paradoxically led to a smaller increase in macrophages and T cells than low dose suggesting an immunosuppressive effect of higher levels.

Phase II trial of intraperitoneal cisplatin and mitoxantrone in patients with persistent ovarian cancer

OBJECTIVE

The aim of this study was to determine the feasibility and efficacy of intraperitoneal cisplatin and mitoxantrone in patients with very small-volume residual disease at second-look surgery after completion of primary platinum-based intravenous chemotherapy.

PATIENTS AND METHODS

Between February 1992 and February 1994, 42 patients were treated with up to five cycles of intraperitoneal cisplatin (100 mg/m2)/mitoxantrone (10 mg/m2). Patients were evaluated for surgically defined response rate and followed for progression-free (PFS) and overall survival (OS) using an intention-to-treat analysis, and grouped according to disease volume at initiation of treatment.

RESULTS

The mean age of all patients was 48.5 years. Thirty patients (71%) were Stage III at diagnosis; 18 patients (43%) had microscopic disease at the initiation of IP therapy, and 24 patients (57%) had macroscopic disease. Twenty-eight patients completed three or more cycles of protocol therapy, and 14 patients were changed to standard intravenous therapy after receiving fewer than three cycles of treatment secondary to catheter-related problems (12 patients), cisplatin ototoxicity (1 patient), or withdrawal from study (1 patient). Using an intention-to-treat analysis, the median PFS was 22.5 months, and the median OS of all patients (N = 42) was 47 months (6-72 months) with a median follow-up of 62.7 months. When grouped according to size of disease at initiation of treatment, the OS has not been reached at 62.7 months of follow-up in patients (N = 18) with microscopic disease.

CONCLUSIONS

(1) The combination of IP mitoxantrone and cisplatin has an unacceptable catheter failure rate due to mitoxantrone toxicity; (2) PFS and OS is longer in patients with microscopic rather than macroscopic residual disease; and (3) intraperitoneal platinum-based chemotherapy in patients with very small-volume residual disease may result in improved survival.

Role of aromaticity of agonist switches of angiotensin II in the activation of the AT1 receptor

We have shown previously that the octapeptide angiotensin II (Ang II) activates the AT1 receptor through an induced-fit mechanism (Noda, K., Feng, Y. H., Liu, X. P., Saad, Y., Husain, A., and Karnik, S. S. (1996) Biochemistry 35, 16435-16442). In this activation process, interactions between Tyr4 and Phe8 of Ang II with Asn111 and His256 of the AT1 receptor, respectively, are essential for agonism. Here we show that aromaticity, primarily, and size, secondarily, of the Tyr4 side chain are important in activating the receptor. Activation analysis of AT1 receptor position 111 mutants by various Ang II position 4 analogues suggests that an amino-aromatic bonding interaction operates between the residue Asn111 of the AT1 receptor and Tyr4 of Ang II. Degree and potency of AT1 receptor activation by Ang II can be recreated by a reciprocal exchange of aromatic and amide groups between positions 4 and 111 of Ang II and the AT1 receptor, respectively. In several other bonding combinations, set up between Ang II position 4 analogues and receptor mutants, the gain of affinity is not accompanied by gain of function. Activation analysis of position 256 receptor mutants by Ang II position 8 analogues suggests that aromaticity of Phe8 and His256 side chains is crucial for receptor activation; however, a stacked rather than an amino-aromatic interaction appears to operate at this switch locus. Interaction between these residues, unlike the Tyr4:Asn111 interaction, plays an insignificant role in ligand docking.

Evaluation of the usefulness of testing for p53 mutations in colorectal cancer surveillance for ulcerative colitis

OBJECTIVE

Immunohistochemical staining for p53 suppressor gene mutations is sensitive and, therefore, has potential for use as a complementary test for dysplasia to improve ulcerative colitis (UC) cancer surveillance program performance.

METHODS

A cohort of 95 patients with long standing pan-UC enrolled in a surveillance program was studied. Archival colonic biopsy specimens were stained for p53 mutations and clinical information was obtained from medical records.

RESULTS

The 37 patients who developed p53 mutations were significantly more likely to develop dysplasia or cancer (relative risk [RR] 4.53, 95% confidence interval [CI] 2.16-9.48). The p53 mutations developed approximately 8 months before low grade dysplasia, 26 months before high grade dysplasia, and 38 months before cancer. Three of seven cancer patients with p53 mutations had Dukes' stage C or D, whereas only one of five cancer patients without p53 mutations had Dukes' C or D; all three patients who died from metastatic cancer had p53 mutations (three of 37 vs 0 of 58, p < 0.03). Folic acid supplementation had a small, significant protective effect for p53 mutations (RR 0.97, CI 0.94-1.00).

CONCLUSION

p53 Mutations 1) are associated with, and likely precede, dysplasia and cancer, 2) are associated with cancer-related mortality, and 3) may possibly be prevented by folic acid supplementation.

Gastrointestinal toxicity and Clostridium difficile diarrhea in patients treated with paclitaxel-containing chemotherapy regimens

OBJECTIVE

The objective of this study was to determine the incidence of grade 3 and 4 gastrointestinal toxicity and the prevalence of Clostridium difficile-associated diarrhea (CDAD) in patients with gynecologic malignancies treated with paclitaxel-based chemotherapy regimens.

METHODS

We retrospectively reviewed the medical records of all patients treated on the Gynecology Service at Memorial Sloan-Kettering Cancer Center from January 1, 1993 to July 1, 1996. We identified all patients treated with paclitaxel during this period and determined the total number of patients hospitalized for symptoms of gastrointestinal toxicity, including nausea, vomiting, diarrhea, and dehydration, within 4 weeks of chemotherapy, as well as the incidence of CDAD among these patients.

RESULTS

Six hundred and twenty-four patients were treated with paclitaxel-containing chemotherapy regimens during the study period, including 55 patients who were treated on a "dose-dense" high-dose protocol for advanced ovarian cancer. Among these, 149 patients (24%) were hospitalized for symptoms of gastrointestinal toxicity. During the study period, a total of 40 cases of CDAD were reported among hospitalized patients on the Gynecology Service and 24 (60%) of these cases occurred in patients who had received paclitaxel within the prior 4 weeks.

CONCLUSIONS

The occurrence of CDAD in patients receiving paclitaxel-containing chemotherapy is not rare and can result in severe dehydration requiring hospitalization. The risk of C. difficile colitis appears to be 2.2% in patients receiving standard-dose regimens and as high as 20% in patients receiving high-dose regimens. This etiology should be considered and treated early in patients presenting with symptoms of gastrointestinal toxicity subsequent to chemotherapy treatments.

Lisofylline sensitizes p53 mutant human ovarian carcinoma cells to the cytotoxic effects of cis-diamminedichloroplatinum (II)

A novel approach to counteracting drug resistance is the development of nontoxic agents that are able to preferentially increase the sensitivity of tumor cells to the cytotoxicity of chemotherapy. The possibility that such an agent could be directed specifically against p53-defective tumor cells led us to study the new methylxanthine, Lisofylline, for its ability to sensitize ovary cancer cells to cis-diamminedichloroplatinum(II) (CDDP). In cell lines lacking functional p53 (SKOV3, SKOV3 CDDP-resistant, OVCAR3, and OVCAR432) Lisofylline (20-100 microM) enhanced the cytotoxicity of CDDP by approximately 50% as measured by the Alamar blue vital dye indicator assay. LSF had no effect on p53 wild-type cell lines: OVCAR 420, 429, and 433. Restoration of wild-type p53 phenotype by transfection of SKOV3 cells with a p53 cDNA expression vector showed reversal of sensitization by Lisofylline to CDDP cytotoxicity. While sensitization to DNA damaging agents by other methylxanthines is related to an abrogation of G2 delay, FACS data found no loss of CDDP-induced G2 block in the cell lines, demonstrating that Lisofylline enhanced sensitization. Cell death was examined by quantitative fluorescence microscopy but no increase in apoptosis attributable to Lisofylline exposure was observed. Our results show that the combination of CDDP and Lisofylline preferentially sensitizes p53-defective cancer cells to the cytotoxic effect of CDDP by a yet undetermined mechanism.

BRCA1 up-regulation is associated with repair-mediated resistance to cis-diamminedichloroplatinum(II)

We sought to identify novel genes associated with cis-diamminedichloroplatinum(II) (CDDP) resistance, and by differential display analysis, we found that the human breast and ovarian cancer susceptibility gene BRCA1 was overexpressed in CDDP-resistant MCF-7 cells. A recent report that BRCA1 and human Rad51 colocalize in S-phase cells suggests a role for BRCA1 in DNA damage repair. We hypothesized that BRCA1 plays a role in DNA damage repair-mediated CDDP resistance. In CCDP-resistant variants of breast and ovarian carcinoma cell lines, MCF-7 CDDP/R and SKOV-3 CDDP/R, we found increased levels of BRCA1 protein, and we determined that the SKOV-3 CDDP/R cell line is significantly more proficient at DNA damage repair. Antisense inhibition of BRCA1 in this cell line resulted in an increased sensitivity to CDDP, a decreased proficiency of DNA repair, and an enhanced rate of apoptosis. These data support the hypothesis that BRCA1 is a gene involved in DNA damage repair.

Application of an enzyme-linked immunosorbent assay for screening of sheep urine and animal tissue for the androgenic steroid trenbolone acetate in the State of Kuwait

This study was undertaken to determine the presence of any residue-positive meat and urine samples from live sheep in the State of Kuwait market by using an enzyme-linked immunosorbent assay (ELISA) method and to examine the accuracy and precision of the method. A total of 350 samples, including 230 sheep urine, 30 beef meat and 90 chicken, were subjected, after extraction, to an ELISA for the determination of their contents of the androgenic hormone, trenbolone acetate. The results obtained showed that the trenbolone acetate levels in the urine ranged from 0.1 to 0.9 ng/ml and in the muscle tissue from 0.02 to 0.05 ng/g all of which are below the maximum residue levels accepted (2.0 ng/g) by FAO/WHO. The mean recovery and CV, respectively, ranged from 36.7% and 5.8 (spiking level to 0.2 ng/g) to 49.6% and 10.4 (spiking level 1.5 ng/g). These results were confirmed by gas chromatography-mass spectrometry analysis (GC-MS). Based on the data obtained, it was concluded that ELISA can be used safely for screening purposes, however, any suspect sample must also be analysed by GC-MS to exclude any false positive identifications.

Nutritional issues and therapy in inflammatory bowel disease

Nutritional issues in inflammatory bowel disease (IBD) often receive inadequate attention both in regard to therapy and nutritionally related complications of IBD. This article reviews much of the research that has evaluated the role of diet in the causation, primary treatment, and adjunctive therapy of both ulcerative colitis (UC) and Crohn's disease (CD). Benefits have been demonstrated in the use of elemental diets or polymeric diets in CD in both acute flare up or maintenance of IBD. A careful team approach can overcome problems in implementing nutritional therapy. Nutrition also has a critical benefit in postoperative CD and perioperative UC. Numerous easily corrected, nutritional abnormalities are often overlooked in patients with IBD, which may have significant consequences. Nutritional therapy may have a central place in the hierarchy of treatment in IBD and further research is critical in this area to better define the benefits of nutrition in IBD.

UCN-01 in ovary cancer cells: effective as a single agent and in combination with cis-diamminedichloroplatinum(II)independent of p53 status

Our goal was to determine the cytotoxicity of 7-OH-hydroxystaurosporine (UCN-01) as a single agent and in combination with cis-diamminedichloroplatinum(II) (CDDP) in a panel of ovarian carcinoma cells. We sought to examine the role of p53 gene function and alterations in cell cycle progression or other mechanisms of action of UCN-01 including perturbation of the apoptosis pathway mediated by NF-kappaB and Bcl-2/Bax. Cytotoxicity was determined from dose-response curves established by the Alamar blue vital dye indicator assay. Restoration of wild-type p53 in a p53 null cell line, SKOV 3, was achieved by transfection of a p53 expression vector. Cell cycle distribution was measured by fluorescence-activated cell sorting analysis of ethidium bromide-stained nuclei. Apoptosis was measured by quantitative fluorescence microscopy. NF-kappaB DNA binding activity was measured by electrophoretic mobility shift assay. Bcl-2 and Bax levels were determined by Western immunoblotting. UCN-01 was effective as a cytotoxic agent alone and in combination with CDDP in all cell lines studied, regardless of p53 status. The degree of sensitization to CDDP conferred by UCN-01, however, was found to correlate with p53 gene status. p53 wild-type cells seem to be more sensitive to the cytotoxic effects of the combination of UCN-01 + CDDP than the p53 mutant cells. This was confirmed in cells in which p53 wild-type function was restored by transfection of p53 cDNA, but these cells are also significantly more sensitive to CDDP alone. The effects of UCN-01 on cell cycle progression also appear to be p53 dependent but may not be the primary mechanism of action. The rate of apoptosis is increased 4-fold in UCN-01 + CDDP-treated cells compared to either agent alone. UCN-01 does not effect NF-kappaB DNA binding activity or Bcl-2 and Bax levels. UCN-01 enhances CDDP cytotoxicity and apoptosis in ovary cancer cells. This occurs regardless of p53 status, but wild-type p53 seems to increase the degree of sensitization.

Polycyclic aromatic hydrocarbons in food products originating from locally reared animals in Kuwait

Analysis for the presence of 12 polycyclic aromatic hydrocarbons (PAHs) in 327 foodstuff samples originating from locally reared animals was carried out. The data revealed that non-carcinogenic PAHs were detected in considerable amounts in several food commodities. The carcinogenic PAH concentrations were relatively low in most of the samples investigated. Among the carcinogenic PAHs detected, chrysene had the highest concentration.

Relationship between the mucosal production of reactive oxygen radicals and density of Helicobacter pylori in patients with duodenal ulcer

OBJECTIVE

To investigate the associations between the mucosal production of reactive oxygen radicals (RORs) in the gastric antrum and duodenum, Helicobacter pylori density and duodenal ulcer (DU).

PATIENTS

Forty-seven endoscoped patients, comprising 22 with DU and 25 non-ulcer subjects, were included in the study.

METHODS

Antral and duodenal biopsies were taken for histology, Helicobacter pylori culture and measurement of chemiluminescence. Biopsies were homogenized and cultured on Columbia blood agar plate. Colonies of H. pylori were counted and bacterial density expressed as colony-forming units (cfu)/mg of biopsy. Chemiluminescence was measured by luminometry and the results expressed as millivolt (mV)/min/mg of biopsy, after subtraction of background count.

RESULTS

Thirty-one of 47 (66%) patients had antral H. pylori and 6/47 (12.8%) had proven duodenal colonization. Increased chemiluminescence (median (interquartile)) was found in H. pylori-infected patients compared to those without H. pylori in antral (90.0 (26.0, 249.0) vs. 7.0 (0.0, 10.0), P<0.001) and duodenal mucosa (22.0 (10.0, 100.0) vs. -2.5 (-10.0, 0.0) P<0.001). A positive correlation was found between antral H. pylori density and chemiluminescence response in both the antrum (r=0.77) and duodenum (r=0.52). DU patients showed an increased chemiluminescence compared to those non-ulcer subjects with or without H. pylori infection in antrum (163.5 (44.5, 297.8) vs. 33.0 (8.7, 168.0) (P=0.046) vs. 2.7 (0.1, 10.0), P<0.01) and duodenum (45.0 (17.5, 100.0) vs. 15.0 (-1.25, 22.5) vs. -2.5 (-10, 0.0), P<0.01).

CONCLUSION

Increased production of RORs in the antrum and duodenum was found to be related to antral H. pylori density and associated with duodenal ulceration. The association between antral H. pylori and ROR release in the duodenum may be important in the pathogenesis of duodenal ulceration.

Partial nephrectomy for pediatric renal cell carcinoma: an unusual case presentation

Nine years after successful treatment of Stage IV neuroblastoma, a 10-year-old white girl was demonstrated to have a complex cystic mass in the upper pole of her solitary right kidney. Partial nephrectomy was performed, disclosing a renal cell carcinoma, predominantly clear cell type. No metastases were detected. Renal cell carcinoma is a rare cause of secondary malignancy. Partial nephrectomy can be used successfully to treat renal cell carcinoma in children.