Novel oral medication delivery system for famotidine

A famotidine wafer that rapidly disperses on the tongue without water is a novel alternative to other histamine2 (H2)-antagonist dosage forms. Benefits associated with such a dosage form include convenience and potentially improved compliance for patients who dislike or have difficulty taking tablets and capsules. This report describes the research of three studies on the famotidine wafer dosage form. In the first trial, the bioequivalence and tolerability of the new 40-mg famotidine wafer and the marketed 40-mg famotidine tablet were studied in a 2-period crossover study (n = 18). The two formulations were bioequivalent as assessed by area under the plasma concentration versus time curve and maximum plasma concentration of famotidine. The plasma concentration of famotidine associated with 50% inhibition of pentagastrin stimulated gastric acid secretion (EC50; 10 ng/mL) was attained on average within 0.5 hours post-dose for the wafer and tablet. In a second trial, the tolerability of the famotidine 20-mg and 40-mg wafers or placebo given twice daily (bid) for 14 days were evaluated (n = 192). Both wafer strengths were well and equally tolerated. In a third trial of 450 subjects, the 40-mg wafer was preferred over tablets by 75% of the subjects, when they were asked to consider the method of administration and flavor. When used as an alternative to tablets and other conventional dosage forms, the wafers have the potential therapeutic benefit of improved compliance. It is concluded that similar systemic exposure, excellent tolerability, palatability, and preference make the famotidine wafer a clinically acceptable and convenient dosage from for patients on H2-antagonist therapy.

Effect of glycyrrhetinic acid on DNA damage and unscheduled DNA synthesis induced by benzo(a)pyrene

Glycyrrhetinic acid (GA) is an active component of Glycyrrhiza uraleusis fisch. In this study, GA was found to inhibit ear edema and ornithine decarboxylase (ODC) activity induced by croton oil in mice. GA could also protect rapid DNA damage and decrease the unscheduled DNA synthesis induced by benzo(a)pyrene. The results demonstrate that GA has a potential cancer chemopreventive activity.

Differential expression of collagen-binding receptors in fetal rat lung cells

Interactions of cells with molecules of the extracellular matrix (ECM) are mediated via specific cell surface receptors. Because collagen is an important ECM component in the developing lung, we investigated the expression of collagen receptors by distal fetal lung epithelial cells and fibroblasts. Cell attachment experiments revealed that fibroblasts but not epithelial cells adhered to various types of collagen. With the use of subunit-specific antibodies, we demonstrated the presence of the collagen integrins alpha 1 beta 1, alpha 2 beta 1, and alpha 3 beta 1 at the fibroblast surface but only the integrin alpha 3 beta 1 on epithelial cells. Affinity chromatography on collagen-Sepharose identified only alpha 1 beta 1 and alpha 2 beta 1 as collagen-binding integrins in extracts of 125I surface-labeled fibroblasts. No collagen-binding receptors were detected in extracts of surface-iodinated epithelial cells. Message for alpha 1- and alpha 2-integrin was readily demonstrated for fibroblasts, but both mRNAs were hardly detectable in epithelial cells. In contrast, epithelial cells expressed significantly greater alpha 3 mRNA levels than fibroblasts. These data demonstrate that alpha 1 beta 1- and alpha 2 beta 1-integrins function as collagen-binding receptors in fetal lung fibroblasts. Distal fetal lung epithelial cells do not express the alpha 1 beta 1- and alpha 2 beta 1-integrins and do not adhere to collagen. The alpha 3 beta 1-integrin, which is expressed by both cell types, does not function as a collagen receptor.

[Comparison of the sensitivity of retinoic acid sensitive and resistant HL-60 cell lines to several anti-leukemia drugs]

By using MTT and trypan blue exclusion assay, the sensitivity of retinoic acid sensitive HL-60 and resistant HL-60/RA cell to six anti-leukemia drugs such as RA, Ara-c, harringtonine was compared. It was found that all five drugs except RA exhibited an approximately equivalent IC50 to HL-60 and HL-60/RA cells. The results suggest that tumor cells may not develop resistance to differentiation inducer and cytotoxic anti-tumor agent parallel. It also suggests that it is reasonable to use a combination of differentiation and cytotoxic anti-leukemia agents concomitantly or sequentially.

Bladder irrigation specimens assayed by fluorescence in situ hybridization to interphase nuclei

Bladder irrigation specimens provide a sampling of the entire bladder urothelium and are the most practical sample for longitudinally monitoring patients. This study presents cross-sectional fluorescence in situ hybridization (FISH) analyses with correlated DNA cytometry data on 76 patients monitored for recurrent bladder tumors. FISH probes complementary to centromeric satellite sequences for chromosomes 1, 7, 9, 11, 15, and 17 were used. Aberrations in copy number were observed for chromosomes 1, 7, 11, and 17 principally in patients with aneuploid tumors. Monosomy of chromosome 9 was observed in 39% of the diploid and 31% of the specimens with high hyperdiploid fraction. Significantly, 24% of patients with a history of bladder cancer but with no clinical evidence of disease exhibited monosomy of chromosome 9. This suggests a persistent and significantly large population of abnormal cells in the absence of clinical evidence of disease. Loss of chromosome 9 relative to DNA ploidy was observed in 24% of patients with no evidence of disease, in 59% of patients with tumor, and in 79% of patients with histologically confirmed transitional cell carcinoma, grades 1-3. Loss of chromosome 15 was also observed in a large percentage of patients. Loss of chromosome 15 was observed in 41% of specimens from patients in whom no tumor was seen, in 38% of specimens from patients with tumor, and in 67% of specimens from patients with histologically confirmed transitional cell carcinoma. Results of this study document the use of bladder irrigation specimens as a specimen source for FISH analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of the nucleotide sequence variation of the antigen-binding domain of DR alpha and DQ alpha molecules as related to the evolution of papillomavirus-induced warts in rabbits

We previously found that regression of skin warts induced by the Shope cottontail rabbit papillomavirus in New Zealand White rabbits, as well as malignant conversion of persistent warts, are linked to a restriction fragment length polymorphism of the major histocompatibility complex class II DR alpha and DQ alpha genes. To find out whether this immunogenetic control could be connected with the antigen binding and presentation function of the alpha 1 domain of class II molecules, we have sequenced the exon 2 of the four DR alpha EcoRI and six of the seven DQ alpha PvuII restriction fragment length polymorphism alleles identified, and deduced the encoded amino acid sequences. We found no amino acid polymorphism among DR alpha alleles, indicating that the alpha 1 domain of the DR alpha chain does not condition wart regression or cancer development. In contrast, 27 of the 82 amino acids of the DQ alpha 1 domain were found variable, defining five amino acid sequence alleles. The restriction fragment length polymorphism allele linked to regression and another allele not linked to regression share the same alpha 1 domain, indicating that wart regression is rather conditioned by a closely linked gene. The most divergent DQ alpha 1 allele, however, was that associated with a higher risk of cancer. Alignment of rabbit and human DQ alpha exon 2 alleles disclosed that amino acid charge variations occur at positions assumed to be important for peptide binding in humans. By modulating the affinity for tumor-specific antigenic peptides, such transitions could affect immune surveillance and, thus, condition the risk for progression to carcinoma of papillomavirus-associated lesions.

Ontogeny and regulation of platelet-derived growth factor gene expression in distal fetal rat lung epithelial cells

Using flow cytometry, thymidine uptake into DNA, and expression of two growth-related genes, histone 3 and c-myc, we found an increase in the proportion of distal lung epithelial cells in the G0/G1 phase of the cell cycle with advancing gestation. Since our previous studies had demonstrated that platelet-derived growth factor (PDGF) is essential for the progression of these cells from the G0/G1 to the S phase of cell cycle, we investigated the gene and protein expression of PDGF-related genes (PDGF-A, PDGF-B, alpha-receptor, and beta-receptor) in distal fetal lung epithelial cells. The cells transcribed all the PDGF-related genes and translated the PDGF-A and PDGF-B mRNAs into protein, as demonstrated by immunocytochemistry and immunoprecipitation. To explore an autocrine role for PDGF in distal fetal lung epithelial cells, intervention studies using PDGF-A and -B chain-specific antisense oligodeoxynucleotides (ODN) were carried out. Antisense PDGF-B ODN, but not antisense PDGF-A ODN, significantly reduced the DNA synthesis of these cells. The inhibitory effect of antisense PDGF-B ODN on DNA synthesis was reversed by the addition of exogenous PDGF-BB, which supports an autocrine role in the DNA synthesis of these cells. We also examined the expression of PDGF genes in distal fetal lung epithelial cells during late gestation. PDGF-A chain and beta-receptor gene expressions declined with advancing gestation, whereas expression of message for PDGF-B chain and alpha-receptor increased. The increases in message for PDGF-B chain and alpha-receptor with advancing gestation were due to a greater rate of transcription, whereas the developmental decrease of PDGF-A chain and beta-receptor mRNAs was caused by a decrease in RNA stability. Taken together with the ODN data, these results suggest that the G0/G1 cell cycle arrest of distal lung epithelial cells during late fetal gestation is due to a decrease in PDGF beta-receptor expression by the cells.

[Chronological characteristics of retinoic acid-induced HL-60 cell differentiation]

HL-60 cells can be induced to differentiate into mature granulocytic cells in a continuous exposure to all-trans retinoic acid (RA) for at least 96 h. In this study, RA was removed after being exposed to HL-60 cells for 12-96h. Then the cells were reincubated in a fresh medium without drug for additional 48-144h and their differentiation markers such as NBT reduction, morphological changes and cytokinetic characteristics were studied. The results demonstrated that once exposed continuously to 1.0 mumol/L RA for at least 48h, the HL-60 cells would proceed to terminal differentiation: about 60-90 percent of the cells became NBT positive, 40-80 percent of cells exhibited decreased nucleus/cytoplasm ratio and marked reduction in the number of nucleoli and displayed matured granulocytic morphology. Cytokinetic studies demonstrated 48-85 percent of cells arrested in G1 phase, which is typical for differentiated cells. However, if the cells were exposed to RA for less than 48h, they would not show differentiation phenotype. These results indicate that 48h exposure is critical for HL-60 cell differentiation induced by RA, and the cell differentiation induced by RA is irreversible and RA-independent.

[Inhibitory effect of a third generation retinoid R8923 and all-trans retinoic acid on two-stage chemical carcinogenesis of BALB/3T3-A31 cells in vitro]

The inhibitory effect of a third generation retinoid R8923 and all-trans retinoic acid (RA) on malignant transformation of Balb/3T3-A31 cells induced by 3-methylcholanthrene (3-MCA) and 12-0-tetradecanoyl phorbol-13-acetate(TPA) was studied in paper. Malignant transformation of Balb/3T3-A31 cells was evaluated by scoring transformation foci and soft agar assay. Actively growing Balb/3T3-A31 cells (1.5 x 10(4) cells per 60-mm-diameter glass dish) were cultured in 5ml of Eagle's Minimum Essential Medium supplemented with 10 percent fetal bovine serum. Twenty-four hours after plating, the cells were treated with 3-MCA (2 micrograms/ml) for 72 hours. TPA was added into the medium at a concentration of 100 ng/ml for 2 weeks. Thirty-six days after cell plating, the transformation foci were counted and the soft agar assay of the cells isolated from each glass dish was performed. Results showed that there were 16.0 +/- 1.58 transformation foci/dish and the colony forming efficiency in soft agar assay was 138.6 +/- 14.47/10(3) cells in 3-MCA and TPA treated dishes (control group). When the cells were exposed to R8923 or RA (at a concentration of 10(-6) M), the transformation foci were 11.2 +/- 0.84 /dish and 9.2 +/- 1.10/dish respectively, and the corresponding colony forming efficiency values were 66.1 +/- 7.68/10(3) cells and 64.8 +/- 4.46/10(3) cells. They were significantly lower than that of the control group. These results demonstrated that R8923 and RA could effectively inhibit 3-MCA and TPA induced malignant transformation of Balb/3T3-A31 cells and suggested that R8923 is a potential drug for cancer chemoprevention.

Recent progress in the study of anticancer drugs originating from plants and traditional medicines in China

Drugs of plant origin have received much attention due to their enormous potential for the prevention and treatment of cancer. Recent progress in the study of anticancer drugs originating from plants and traditional medicines in China is reviewed in this paper, with particular emphasis on taxol, daidzein, acetyl boswellic acid, curcumin and ginsenosid Rh2.

[A study on chemoprevention of retinamide II from cervical precancerous lesions]

The patients with cervical precancerous lesions were double-blindly randomized into two groups. The one was treated with retinamide II (RII) suppository intravaginally and the other with placebo, once daily for 50 days as a course. The results showed precancerous lesions in 68.57% of the patients disappeared, with an overall effective rate of 74.29% after two-course treatment with RII. Its long-term curative effect approximated to that with laser beam radiation and electrocautery (P > 0.05), and differed significantly (P < 0.01) from that with common antiphlogistic. So, RII can be used as a major measure in prevention and treatment for cervical cancer in high-incidence areas in our country.

Highlight on the studies of anticancer drugs derived from plants in China

Recent progress on the study of anticancer drugs originating from plants in China is reviewed in this paper. Guided by the experience of traditional Chinese medicine, several new drugs have been found. Indirubin from Indigofera tinctoria is useful for the treatment of chronic myelocytic leukemia. Irisquinone from Iris latea pallasii and 10-hydroxy camptothecin from Camptotheca accuminata have exhibited definite activity on rodent tumors. Recent studies indicate that ginsenoside Rh2 is an inducer of cell differentiation in melanoma B-16 cells in vitro. Pharmacological studies have demonstrated that curcumin from Curcuma longa is an antimutagen as well as an antipromotor for cancer. Daidzein and acetyl boswellic acid have been shown to be effective inducers of cell differentiation in HL-60 cells. Guided by the chemotaxonomic principle of plants, harringtonine and homoharringtonine isolated from Cephalotaxus hainanesis have exhibited significant antileukemia activity and are widely used in clinics in China. Taxol from Taxus chinensis has been shown to be an important new anticancer drug with unique chemical structure and mechanism of action. The continuous search for new anticancer drugs from plants will be a fruitful frontier in cancer treatment and chemoprevention.

Fetal lung epithelial cells express receptors for platelet-derived growth factor

There is increasing evidence to suggest that platelet-derived growth factor (PDGF) or PDGF-like molecules play a role in fetal lung morphogenesis. Our previous studies demonstrated that fetal lung epithelial cells respond mitogenically to exogenous PDGF, while fetal lung fibroblasts respond with increased glycosaminoglycan synthesis. To further study the target cells of PDGF in fetal rat lung, we investigated the presence and nature of PDGF receptors in fetal lung cells. Functional PDGF receptors were expressed on normal epithelial cells of fetal rat lung. All three isoforms of PDGF (AA, AB, and BB) were mitogenic for quiescent epithelial cells. Northern blot and protein analysis demonstrated the presence of PDGF alpha-receptor and PDGF beta-receptor. All isoforms of PDGF enhanced tyrosine kinase activity and stimulated receptor autophosphorylation. In contrast, fetal lung fibroblasts expressed only the PDGF beta-receptor. PDGF-AB and PDGF-BB, but not PDGF-AA, stimulated tyrosine kinase activity. No PDGF isoform was mitogenic for quiescent fibroblasts. However, PDGF-BB stimulated fibroblast proliferation on a collagen type I substratum in the presence of transferrin. Binding experiments with [125I]PDGF-AA and [125I]-PDGF-BB to epithelial cells and fibroblasts confirmed these observations.

Differentiation of promyelocytic leukemia cells HL-60 induced by daidzein in vitro and in vivo

We have screened more than one thousand synthetic and natural chemicals to explore differentiation inducers and found that daidzein has potent differentiation-inducing activity for human leukemia HL-60 cells, both in vitro and in vivo. In vitro study showed that daidzein at concentrations exceeding 10 micrograms/ml caused inhibition of HL-60 cells; and it induced differentiation of the cells into granulocytic lineage as judged by NBT reduction activity, phagocytic ability and morphological characteristics. Flow cytometry study indicated that daidzein arrested HL-60 cells in the G1 phase. The growth of HL-60 cells in the subrenal capsules of mice and in diffusion chambers implanted into the peritoneal cavities of mice was inhibited by 50 mg/kg daidzein. HL-60 cells treated with daidzein in vivo also exhibited characteristic morphological changes of matured cells. Moreover, the colony forming efficiency of HL-60 cells in diffusion chambers in mice was markedly inhibited by the administration of daidzein.

[Anti-oxidative effects of R8605, a third-generation retinoid]

The anti-oxidative effects of R8605, a compound of the third generation retinoids, have been studied. R8605 exhibited pronounced inhibitory effects on FeSO4/cysteine and NADPH/vitamin C-induced lipid peroxidation of rat liver microsome as well as on H2O2-induced lipid peroxidation of erythrocytes: Their IC50's were 9.8, 17.6 and 20.3 mumol/L, respectively. R8605 decreased the generation of superoxide anion (O2-.) in a xanthine/xanthine oxidase system and also elevated hepatic superoxide dismutase (SOD) activity in mice. Therefore R8605 shows potent antioxidative effects and this is likely of importance in its chemopreventive actions.

[Anti-carcinogenic and anti-promoting effects of retinoid R8605]

R8605 belongs to the third generation retinoid and was found during the systematic screening of cancer chemopreventive agents in our institute. Based on the theory of multistage carcinogenesis, the anti-carcinogenic and anti-promoting effects of R8605 as well as its possible anti-promoting mechanisms were studied. Experiments proved that R8605 (50 mg/kg and 25 mg/kg, i.g.) significantly inhibited the growth of skin papillomas induced by 7, 12-dimethylbenz[a]anthracene and croton oil in mice and exhibited a potent anti-promoting action. In addition, R8605 (50 mg/kg and 25 mg/kg, i.g.) strongly inhibited the induction of ornithine decarboxylase (ODC) activity of mouse skin epidermis by croton oil. At a dose of 100 mg/kg of R8605 (i.g.) croton oil-induced ear edema in mice was suppressed. These results suggest that the anti-promoting effect of R8605 might be associated with its anti-inflammatory action and its inhibitory effect on ODC activity.

[Inhibitory effects of several antitumor drugs on the growth of HL-60 cells in SRC of mice]

Human promyelocytic leukemia HL-60 cells provide a useful model system for the study of cell differentiation in vitro. Here the growth of HL-60 cells as a solid clot with fibrin in subrenal capsules (SRC) of mice was studied. The cell volume of HL-60 cells increased 5 and 15-fold between 6-9 days after transplantation into normal and CYT immunosuppressed mice, respectively. Histological study revealed typical proliferation and invasion characteristics of HL-60 cells and higher tumor cell density. RA, RII, Ara-C, Harringtonine and HMBA significantly inhibited the growth of HL-60 cells in SRC of mice. This model provides a useful system for the study of the effect of drugs on cultured tumor cells or leukemia cell lines in vivo.

Androgen-producing bilateral large cortical adrenal adenomas associated with polycystic ovaries in a young female

An association of bilateral large adrenocortical androgen-producing adenomas with polycystic ovaries in a young female is presented. She developed mild hirsutism and secondary amenorrhoea at the age of 17, and was treated for 3 years with an anti-androgen (cyproterone acetate) and ethinyloestradiol. Routine follow-up at the age of 21 showed bilateral large adrenal tumours and polycystic ovaries, together with high serum testosterone and dehydroepiandrosterone sulphate values. Bilateral adrenalectomy was performed, which resulted in lowering of the elevated androgens, and large bilateral adrenocortical adenomas were confirmed histologically. Contrary to expectations, the polycystic appearance of the ovaries persisted after adrenalectomy. This case supports the possible role of adrenal androgens in the pathogenesis of polycystic ovaries as well as the possibility of the persistence of polycystic ovaries without adrenal androgens once they have developed.

Linkage of regression and malignant conversion of rabbit viral papillomas to MHC class II genes

Human papillomaviruses associated with cutaneous and anogenital cancers induce intraepithelial precursor lesions which may regress spontaneously or progress into invasive carcinomas. Cell-mediated immune responses are probably involved in regression of precancerous lesions and the polymorphism of the genes responsible may thus have a key role in the variability of the host response. Skin warts and cancers induced in rabbits by Shope papillomavirus provide a model to test this hypothesis. We analysed a restriction-fragment-length polymorphism of major histocompatibility complex class I and class II genes and T-cell receptor beta-chain genes in infected domestic rabbits. We found a strong linkage between wart regression and a DR alpha EcoRI fragment, and an increased relative risk of malignant transformation associated with a DQ alpha PvuII fragment. This indicates a genetic control of wart evolution, involving genes in the class II region of the major histocompatibility complex.

A research for the relationship between human papillomavirus and human uterine cervical carcinoma. I. The identification of viral genome and subgenomic sequences in biopsies of Chinese patients

Biopsies from 318 cases with squamous cell carcinoma of the uterine cervix, 48 with cervical and vulvar condylomata, 14 with cervical intraepithelial neoplasia (CIN), 34 with chronic cervicitis and 24 with normal cervical epithelium were collected from different geographic regions with different cervical cancer mortalities. The DNA.DNA dot-blot and Southern blot hybridization results show that there is a close relationship between HPV-16 and the uterine cervical squamous cell carcinoma in China. One very interesting observation is that the finding of HPV-16-homologous DNA differs significantly among five geographic regions, and corresponds with the mortalities from cervical cancer of these five regions. HPV-11 was found mainly in benign lesions. The rate of detection of HPV-16 in Chinese women increased from 8.3% in normal cervical epithelium to 20% in chronic cervicitis, 28% in cervical condyloma, 50% in CIN and 60.4% in cervical cancer. It is suggested that HPV-16 infection may be an etiological factor in the development of human cervical carcinoma. From the results of Southern blot hybridization, it appeared that HPV-16 DNA had been integrated into the genome of the host cell in cervical cancer. Whereas the HPV-16 DNA sequence was only present as an episome in normal cervical epithelium and cervical benign lesions. The rate of occurrence of E6-E7 genes is the highest (88.9%) compared with that of other subgenomic fragments of HPV-16 in specimens of human cervical cancer in China. This implies that E6 and E7 may be the oncogenic genes of HPV-16 and play an important role in the carcinogenesis of human cervical epithelial cells. The amplification and rearrangement of the c-myc protooncogene are closely associated with the occurrence of cervical cancer. The results presented here revealed that the activated c-myc oncogene may cooperate with HPV-16 in the carcinogenic processes.

[Delayed gastric emptying in diabetes mellitus]

Function of gastric motility was studied in thirty one diabetes mellitus patients by testing gastric emptying time (GET). The test was performed by giving patients food labelled with 99mTc. The results showed that GET in patients with diabetes mellitus was significantly delayed as compared with that in the controls (P less than 0.001). 15 among the 31 diabetic patients had delayed GET, accounting for 48.4%. There was no difference in age, duration of the disease, treatment regimen and microvascular complications between patients with delayed GET and those with normal GET. The only difference was the obviously increased incidence of autonomic nerve dysfunction in the former group of patients (P less than 0.05). We concluded that the incidence of delayed gastric emptying time was higher in diabetic patients with autonomic neuropathy.

[Pharmacological studies of N-4-(hydroxycarbophenyl) retinamide]

Our studies show that the growth of transplantable chondrosarcoma in rats is inhibited significantly by N-4-(hydroxycarbophenyl) retinamide (RII) at a dosage of 50 mg/kg. RII show a weak ability to induce the differentiation of HL-60 cells at a concentration of 1 umol/L. However, most of the HL-60 cells were induced to differentiate along granulocyte lineage after exposure to RII (1 mumol/L) and S86019 (10 micrograms/ml). Flow cytometry studies indicated that the majority of HL-60 cells were arrested in G1 phase by RII plus S86019. Northern blot analysis clearly demonstrated that c-myc expression was inhibited after treating HL-60 cells with RII plus S86019 for 12 hours. Moreover, thymidylate synthetase mRNA transcription was inhibited in those differentiated cells.

[Iodine levels in salt for human consumption and aspects of iodine prophylaxis in Yugoslavia]

Iodine content of iodinated salt intended only for human consumption was eyamined in samples from all domestic manufacturers (salt mines in: Tuzla, Pag, Ulcinj, Ston, Nin, Seca-Portoroz). Sampling was made from commercially available packs (1 kg) or from food industries (large packs). It was established that iodine content of examined samples (57) varied considerably and ranged from 1.8 to 12.2 mg iodine/kg salt. Iodinated salt from the Tuzla and Pag salt mines contained iodine within the prescribed limits in both small and large packs. Similar finding of iodine content was in the small packs of the Ulcinj salt mines, however, their large packs (10 kg) had a markedly low level of iodine (1.8-4.7 mg). Lower iodine content was also noted in salts (1 kg) from the Nin, Ston and Seca-Portoroz mines. Of the 57 examined samples in 70% iodine content was lower than the prescribed dose (7.6 mg). In addition, some mines had low iodine content in all of the 100% of their respective samples. Ever since iodine prophylaxis was introduced in Yugoslavia a number of factors influenced the decrease of iodine intake by the organism to a considerable degree. The results of our investigations and some epidemiological data indicate that the issue of increasing the amount of iodine from the present 7.6 to 15 mg iodine/kg salt should be reconsidered. Besides, it is necessary to arrange the systematic quality control of iodinated salt.

Prolactin secretion in myotonic dystrophy

In order to evaluate prolactin secretion in females with myotonic dystrophy (MD) prolactin responses to TRH, metoclopramide and bromocriptine were studied in 13 women with myotonic dystrophy (10 normoprolactinaemic and 3 hyperprolactinaemic) and 8 healthy women. Following TRH administration mean maximal net increase was significantly higher in a group of normoprolactinaemic patients with MD in comparison to controls (p less than 0.05). In three patients with increased basal prolactin levels an exaggerated prolactin response to TRH has been observed. Normal prolactin response in a group of normoprolactinaemic as well as in hyperprolactinaemic patients have been observed following metoclopramide bolus injection. Following bromocriptine administration, maximal net decrease in prolactin levels has been found to be greater in normoprolactinaemic patients compared to healthy subjects, although the difference was statistically insignificant. The suppressive action of bromocriptine was more pronounced in patients with hyperprolactinaemia. Those results showed that there is some derangement in prolactin secretion in myotonic dystrophy leading to increased prolactin levels in some patients. Although the mechanism of this derangement has not been clarified yet it seems that it is not mediated via dopaminergic receptors.

[Influence of culture conditions on the growth of murine bone marrow stromal colony-forming cells (CFU-f) in vitro]

Several factors which may influence the colony-forming efficiency of mouse CFU-f, including media, culture dishes, mouse strains, and O2 concentrations in the incubator were tested. Among them, the O2 concentration was found to be the most important factor, when a mixed gas consisting of 5% O2, 5% CO2 and 90% N2 was used to replace the usual 5% CO2 in air, the colony-forming efficiency of CFU-f increased markedly and the influence of other factors on cell growth diminished. Although the use of a lit candle to consume O2 in the air provided good conditions for colony formation of several tumor cell lines in soft agar, it is not suitable for the growth of CFU-f.

[Serum antithyroid antibodies in patients with pernicious anemia]

We investigated the incidence of thyroid auto-antibodies and their relationship to antigastric antibodies in 20 euthyroid patients with pernicious anaemia. To evaluate possible thyroid dysfunction we also measured total level of thyroid hormones (TT3 and TT4) and TSH in our patients. Histologic evidence of autoimmune atrophic gastritis and intestinal metaplasia was obtained in 15 patients. We found that it was surprisingly high incidence of thyroid auto-antibodies in patients with pernicious anaemia, particularly in the group with intestinal metaplasia (antithyreoglobulin antibodies 71% and antimicrosomal antibodies 100%). The incidence of antigastric antibodies in these patients was similar to that of those with significant antithyroid antibodies (16/18). Total triiodo thyronine and TSH were significantly higher in the patients with pernicious anaemia than in the control group (p less than 0.05), in the normal range. The results of our study suggest that this upset in immunological physiology is due to a more generalized defect in immune tolerance.

[Adrenocortical "incidentalomas" as a diagnostic and therapeutic problem]

P. Carpenter (1986) used the term "incidentalomas" in connection with all incidentally discovered adrenal masses. Previously these masses were frequent incidental discoveries at autopsies, but now, with the increasing use of abdominal computed tomography. In the last 10 years 5 patients with incidentally diseases, significant number of them have been detected. In the last 10 years 5 patients with incidentally discovered adrenal masses (4 males and 1 female, aged from 37 to 66 years) were examined and treated in our Department. Long-lasting arterial hypertension was found in all of them, and in one patient here was impaired glucose tolerance with further evolution of diabetes. A possible excessive secretion of glucocorticoids, mineralocorticoids, androgenes and catecholamines was excluded. However, markedly elevated urinary excretion of pregnanediol, proved in all patients, indicated to a possible preservation of the first reaction in the biosynthesis of cortisol, at least synthesis of pregnenolone from cholesterol. One patient, submitted to a regular functional and morphological evaluation of previously discovered 'incidentaloma', showed no sign of expansion or pathological hormonal activity. Four patients were operated because of the suspected expansion and malignant alteration of the adrenal nodus. The histological proof of adrenocortical adenoma or hyperplasia, composed of the 'fasciculata-like' cells, postoperatively maintained elevated values of steroid precursors in urine, and also a finding of adrenocortical noduses in remained adrenal noduses, confirmed the presumption that such masses could be the non-essential finding in long-lasting arterial hypertension and degenerative changes during aging.

[Cytocidal action of homoharringtonine on L1210 cells in vitro]

The proliferation of L 1210 cells ceased rapidly after they were exposed to homoharringtonine (HH) 1 microgram/ml during exponential growth phase. However, 25.3% of the cells were still able to form colonies in soft agar if HH was removed after 24 h of incubation (the colony-forming efficiency for control cells was 62.5%). The clonogenic cells survived from the treatment were still sensitive to HH-continuous exposure. The IC50 of the treated and control cells were 15 and 20 ng/ml, respectively. Yet, the sensitivity of the treated cells to cytarabine decreased enormously. For instance, the survival rate of HH-treated cells remained at 100% level after they were exposed to cytarabine 4-8 micrograms/ml for 1 h, but only 40% control cells survived from the same treatment. When cells were continuously exposed to HH 0.4 micrograms/ml, the colony-forming efficiency decreased exponentially as a function of exposure time. The T1/2 of the clonogenic cells was about 18 h. The DNA contents in L 1210 cells was measured with a flow-cytometer. The results showed that the cell-cycle progress in all cells was interrupted by HH, regardless which phase they belonged to. So the cells seemed to be in a "frozen" state and the histogram unchanged.

[Secondary prevention of esophageal cancer--intervention on precancerous lesions of the esophagus]

In 1983, intervention of precancerous lesion of esophagus was undertaken in the high risk area of esophageal cancer, Heshun Village, Linxian County. It had been expected that cancerous degeneration rate of esophageal dysplasia should be reduced by 50% so as the prevention of esophageal cancer could become possible. 6758 subjects of the general population aging from 40 to 65 were examined by esophageal exfoliative cytology, 1729 had marked dysplasia and 2411 had mild dysplasia of esophageal epithelium. Those with marked dysplasia were randomized into 3 groups to take their respective medication: antitumor B (Chinese herbs); retinamide (4-Ethoxycarbophenylretinamide) and placebo. The subjects with mild dysplasia were divided randomly into 2 groups for treatment by riboflavin and placebo. 95% of the subjects had taken 90% or more of the total medication for 3 years, at the end of which they were reexamined by esophageal exfoliative cytology. The reexamination rate was 94.1%. The incidence of esophageal cancer in the antitumor B group (3.9%) was reduced by 53% as compared with that of the placebo group (8.3%). This difference had statistical significant (means 2 = 7.672, P less than 0.05). The incidence of esophageal cancer in retinamide and riboflavin groups were reduced by 33.7% and 19% as compared with those of the control groups. The regression rate of dysplasia in the treatment groups were increased than that of the control groups. The above results showed that our hypothesis about the secondary prevention of esophageal cancer is correct. The intervention of precancerous lesion of the esophagus is effective in the prevention of esophageal cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

[Chemoprevention of cancer of the uterine cervix--preliminary study on the intervention of the cervical precancerous lesion by retinamide RII]

Twenty seven women with mild, moderate or severe cervical dysplasia proven by pathology were treated by retinamide RII suppository. Retinamide RII suppository, 10 mg QD, was given intravaginally for six months (three months as a course). Clinical examination, Papanicolaou cytology and tissue biopsy under colposcope were carried out before and after treatment. The results indicated that after the second course, 26 out of 27 patients responded; of them, precancerous lesions disappeared in 24 and even normal squamous epithelium was observed in 3. The overall response rate was 96.29% and the marked response rate was 88.89%. The general side effects were mild. There was little cervical and vaginal irritation which was well tolerated. The results of this clinical trial make available a practical base for chemoprevention of cervical cancer.