Therapeutic effect of Castellani's paint in patients with an itchy ear canal.

OBJECTIVE: To examine the effects of Castellani's paint on symptomatic relief and skin flora in patients with an itchy external ear canal. METHODS: Subjective pruritus scores, and erythema and desquamation scores, were noted in 61 patients with an itchy external ear canal. External ear canal skin swabs were taken for bacterial and fungal cultures. Patients were then randomly divided into three groups: either Castellani's paint (group one) or steroid ear drops (group two) were instilled, or non-impacted cerumen was removed (group three). Patients were re-assessed at one month after the initial visit. RESULTS: After treatment, subjective pruritus scores were significantly lower in all groups, erythema scores were significantly decreased in group one, and desquamation scores were significantly reduced in groups one and two, when compared with pre-treatment scores. Reproduction density of bacteria including normal flora was decreased in group one. However, the types of bacteria that constitute the normal flora of the external ear canal were unchanged. CONCLUSION: Castellani's paint can be administered safely, effectively and easily, without affecting the type of external ear canal skin bacteria, in patients with an itchy external ear canal.

Squamous cell carcinoma of the colon with an elevated serum squamous cell carcinoma antigen responding to combination chemotherapy.

Primary squamous cell colorectal carcinomas are uncommon, and their characteristics are not well known. They seem to occur most commonly in the fifth decade of life with a slight predominance for men. The most commonly reported anatomic locations are the rectum and the proximal colon. Clinical features and common diagnostic methods do not easily differentiate squamous cell colorectal carcinomas from adenocarcinomas. Because of their extremely rare occurrence, it is difficult to study their natural course, clinical behavior, and response to therapy. This report presents the case of a pure squamous cell colorectal cancer and provides a brief review of the literature, which includes 60 previously published cases. The case of a patient with T3N2M0 primary squamous cell carcinoma of the rectosigmoid colon, which was initially treated with abdominoperineal resection followed by adjuvant chemotherapy and radiation, is presented. During the follow-up, an elevated squamous cell carcinoma antigen (SCC Ag) level led to restaging computed tomography scans, which confirmed recurrent metastatic disease in the liver. Response to chemotherapy with a decrease in tumor size correlated with a decrease in the serum SCC Ag level. Although SCC Ag has been used as a tumor marker for squamous cell cancers of the lung, head and neck, uterine cervix, and esophagus, this is the first reported case of a squamous cell colon carcinoma presenting with an elevated SCC Ag at the time of recurrence. In addition, this patient showed an objective partial response to combination chemotherapy, with a decrease in the serum level of this tumor marker.

In vitro selection of an RNA sequence that interacts with high affinity with thymidylate synthase.

Previous studies have shown that the repressive effect of thymidylate synthase (TS) mRNA translation is mediated by direct binding of TS itself to two cis-acting elements on its cognate mRNA. To identify the optimal RNA nucleotides that interact with TS, we in vitro synthesized a completely degenerate, linear RNA pool of 25 nt and employed in vitro selection to isolate high affinity RNA ligands that bind human TS protein. After 10 rounds of selection and amplification, a single RNA molecule was selected that bound TS protein with nearly 20-fold greater affinity than native, wild-type TS RNA sequences. Secondary structure analysis of this RNA sequence predicted it to possess a stem-loop structure. Deletion and/or modification of the UGU loop element within the RNA sequence decreased binding to TS by up to 1000-fold. In vivo transfection experiments revealed that the presence of the selected RNA sequence resulted in a significant increase in the expression of a heterologous luciferase reporter construct in human colon cancer H630 and TS-overexpressing HCT-C:His-TS+ cells, but not in HCT-C18 cells expressing a functionally inactive TS. In addition, the presence of this element in H630 cells leads to induced expression of TS protein. An immunoprecipitation method using RT-PCR confirmed a direct interaction between human TS protein and the selected RNA sequence in transfected human cancer H630 cells. This study identified a novel RNA sequence from a degenerate RNA library that specifically interacts with TS.

Thymidylate synthase protein and p53 mRNA form an in vivo ribonucleoprotein complex.

A thymidylate synthase (TS)-ribonucleoprotein (RNP) complex composed of TS protein and the mRNA of the tumor suppressor gene p53 was isolated from cultured human colon cancer cells. RNA gel shift assays confirmed a specific interaction between TS protein and the protein-coding region of p53 mRNA, and in vitro translation studies demonstrated that this interaction resulted in the specific repression of p53 mRNA translation. To demonstrate the potential biological role of the TS protein-p53 mRNA interaction, Western immunoblot analysis revealed nearly undetectable levels of p53 protein in TS-overexpressing human colon cancer H630-R10 and rat hepatoma H35(F/F) cell lines compared to the levels in their respective parent H630 and H35 cell lines. Polysome analysis revealed that the p53 mRNA was associated with higher-molecular-weight polysomes in H35 cells compared to H35(F/F) cells. While the level of p53 mRNA expression was identical in parent and TS-overexpressing cell lines, the level of p53 RNA bound to TS in the form of RNP complexes was significantly higher in TS-overexpressing cells. The effect of TS on p53 expression was also investigated with human colon cancer RKO cells by use of a tetracycline-inducible system. Treatment of RKO cells with a tetracycline derivative, doxycycline, resulted in 15-fold-induced expression of TS protein and nearly complete suppression of p53 protein expression. However, p53 mRNA levels were identical in transfected RKO cells in the absence and presence of doxycycline. Taken together, these findings suggest that TS regulates the expression of p53 at the translational level. This study identifies a novel pathway for regulating p53 gene expression and expands current understanding of the potential role of TS as a regulator of cellular gene expression.

Identification of in vivo target RNA sequences bound by thymidylate synthase.

We developed an immunoprecipitation-RNA-random PCR (rPCR) method to isolate cellular RNA sequences that bind to the folate-dependent enzyme thymidylate synthase (TS). Using this approach, nine different cellular RNAs that formed a ribonucleoprotein (RNP) complex with thymidylate synthase (TS) in human colon cancer cells were identified. RNA binding experiments revealed that seven of these RNAs bound TS with relatively high affinity (IC50 values ranging from 1.5 to 6 nM). One of the RNAs was shown to encode the interferon (IFN)-induced 15 kDa protein. Western immunoblot analyses demonstrated that the level of IFN-induced 15 kDa protein was significantly decreased in human colon cancer H630-R10 cells compared with parent H630 cells. While the level of IFN-induced 15 kDa mRNA expression was the same in parent and TS-overexpressing cell lines, the level of IFN-induced 15 kDa RNA bound to TS in the form of a RNP complex was markedly higher in H630-R10 cells relative to parent H630 cells. These studies begin to define a number of cellular target RNA sequences with which TS interacts and suggest that these TS protein-cellular RNA interactions may have a biological role.

Thymidylate synthase gene amplification in human colon cancer cell lines resistant to 5-fluorouracil.

A series of 5-fluorouracil (5-FU)-resistant human colon H630 cancer cell lines were established by continuous exposure of cells to 5-FU. The concentration of 5-FU required to inhibit cell proliferation by 50% (IC50) in the parent colon line (H630) was 5.5 microM. The 5-FU IC50 values for the resistant H630-R1, H630-R10, and H630-R cell lines were 11-, 29-, and 27-fold higher than that for the parent H630 cell line. Using both the radioenzymatic 5-fluoro-2'-deoxyuridine-5'-monophosphate (FdUMP) binding and catalytic assays for measurement of thymidylate synthase (TS) enzyme activity, there was significantly increased TS activity in resistant H630-R1 (13- and 23-fold), H630-R10 (37- and 40-fold), and H630-R (24- and 34-fold) lines, for binding and catalytic assays, respectively, compared with the parent H630 line. The level of TS protein, as determined by western immunoblot analysis, was increased markedly in resistant H630-R1 (23-fold), H630-R10 (33-fold), and H630-R (26-fold) cells. Northern analysis revealed elevations in TS mRNA levels in H630-R1 (18-fold), H630-R10 (39-fold), and H630-R (36-fold) cells relative to parent H630 cells. Although no major rearrangements of the TS gene were noted by Southern analysis, there was significant amplification of the TS gene in 5-FU-resistant cells, which was confirmed by DNA slot blot analysis. These studies demonstrate that continuous exposure of human colon cancer cells to 5-FU leads to TS gene amplification and overexpression of TS protein with resultant development of fluoropyrimidine resistance.

Bone marrow aplasia and severe skin rash after a single low dose of methotrexate.

A 64 year old man with recurrent metastatic squamous cell carcinoma of the head and neck developed severe skin rash and bone marrow aplasia 4 and 7 days, respectively, following a single dose of 40 mg/m2 methotrexate (MTX). Skin rash involved regions of the face, lower abdomen, back, buttocks and both upper thighs. Biopsy of the skin rash demonstrated superficial perivascular lymphocytic infiltrate and was consistent with a drug reaction. Peripheral blood count revealed pancytopenia and a bone marrow biopsy was consistent with aplasia. Blood counts returned to normal 6 days after institution of granulocyte colony stimulating factor therapy. In the absence of mucositis or diarrhea, severe dermatologic toxicity following a single low dose of the drug suggests an 'allergic' or acute hypersensitivity reaction to MTX in this patient. Development of an extensive skin rash following a single dose of MTX may be an early warning sign for life-threatening bone marrow aplasia.

Thymidylate synthase binds to c-myc RNA in human colon cancer cells and in vitro.

Using an immunoprecipitation-reverse transcription-PCR technique, we characterized a thymidylate synthase (TS) ribonucleoprotein complex in cultured human colon cancer cells that consists of TS protein and the mRNA of the nuclear oncogene c-myc. TS protein is complexed in intact cells with the C-terminal coding region of c-myc mRNA that includes nucleotide positions 1625 to 1790. RNA electrophoretic gel mobility shift assays confirm a specific interaction between TS protein and c-myc mRNA and provide additional evidence that the C-terminal coding region represents an important cis-acting regulatory element. Further evidence demonstrates that the in vitro translational efficiency of c-myc mRNA is inhibited as a result of its direct interaction with TS protein. In addition, the presence of exogenous c-myc mRNA specifically relieves the inhibitory effects of TS protein on TS mRNA translation.

DNA flow cytometry of colorectal carcinoma: correlation of DNA stemlines with other prognostic indices.

DNA flow cytometry (FCM) was performed on paraffin-embedded tissue blocks of 38 surgically resected colorectal carcinomas (CRC). Forty-seven percent of tumors exhibited aneuploidy and 53% were diploid. Seventy-two percent of patients in the aneuploid but only 35% in the diploid group were alive after a mean follow-up of 30.7 and 28.8 months (p = 0.01), and 5-yr survival of 56.7% and 11.7%, respectively (p less than 0.05). The site of tumor location, Dukes' stage, and serum CEA level did not predict a certain DNA stemline. However, irrespective of the ploidy pattern, a serum CEA level greater than 5.0 was associated with a higher mortality and poor 5-yr survival (p less than 0.005). Similarly, advanced Dukes' stage was associated with higher mortality (p less than 0.05). Forty-six percent of the patients with lesions that were Dukes' B2 or advanced stage received adjuvant therapy. Eighty-five percent of this subgroup of patients died; 18% of these patients had aneuploid tumors. The role of FCM in the assessment of prognosis of CRC deserves further clinical evaluation in a randomized control trial.

Lactate dehydrogenase and its isoenzymes in serum from patients with multiple myeloma.

Concentrations of total lactate dehydrogenase (LDH; EC 1.1.1.27) and LDH isoenzyme patterns were studied in serum of 19 patients with multiple myeloma and in 19 healthy controls. Patients were divided into three groups (pretreatment, nonresponders, and responders to treatment), based on their clinical status at the time of blood sampling for LDH. The LDH values were found to be significantly higher (P less than 0.05) in the pretreatment group and in the nonresponders than in the responders and the control group, the mean +/- SE values being 445 +/- 35 and 532 +/- 75 units/mL vs 349 +/- 75 and 190 +/- 7.1 units/mL, respectively. Compared with responders and healthy controls, newly diagnosed patients and nonresponders had slight diminutions in LDH-1 and LDH-2, but increased LDH-3. We conclude that determination of LDH and its isoenzymes in serum can be of value as prognostic factors in patients with multiple myeloma.

Effects of oral prazosin on total plasma digoxin levels.

Prazosin and digoxin are frequently coadministered in clinical practice. To determine the effects of oral prazosin treatment on steady-state digoxin levels, 20 patients receiving a constant maintenance dose of digoxin, who had normal renal and liver functions and were not receiving any other treatment, were given 5 mg of prazosin for 3 days. Plasma digoxin levels were measured before, on days 1 and 3 of prazosin treatment, and after prazosin had been discontinued. It was found that prazosin significantly increased plasma digoxin levels. On discontinuation of prazosin digoxin levels returned to their previous values.

[The fungal flora of the air in the villages around Carsamba, Northern Turkey]. / Carsamba Kizilot Saglik Ocagina bagli köylerde havanin fungal florasi.

The fungal flora of the air was investigated in 13 villages of Samsun, Carsamba, Kizilot Health Center in December and February. In most of the villages, Penicillium and Alternaria were isolated most frequently. Scopulariopsis and Fusarium were also found at high quantity in the air.