Inhibition of skin tumors in DMBA-induced complete carcinogenesis system in mice by garlic (Allium sativum)

The chemopreventive action of garlic extract on DMBA-induced complete skin carcinogenesis system was studied in random bred, 6-7 weeks old, male Swiss albino mice. Topical weekly application of DMBA for 25 weeks at two dose levels, i.e. 200 nmol during the first week followed by 100 nmol during subsequent weeks, or 400 nmol during the first week followed by 200 nmol during subsequent weeks, resulted in 73.9% and 100% tumor incidences respectively. When garlic extract was topically applied twice daily for 3 days every week prior to above-stated dose schedules of DMBA, the incidences of tumors were reduced to 31.8% (P less than 0.01) and 43.4% (P less than 0.01) respectively.

Chemopreventive action of garlic on methylcholanthrene-induced carcinogenesis in the uterine cervix of mice

The present paper reports the chemopreventive action of garlic on 3-methylcholanthrene (MCA)-induced carcinogenesis in the uterine cervix of virgin young adult Swiss albino mice. Insertion of sterile cotton thread impregnated with beeswax containing approximately 600 micrograms of MCA inside the canal of uterine cervix results in the appearance of precancerous and cancerous lesions in the cervical epithelium. In this experimental cervical carcinogenesis model system, if garlic was administered orally at the dose level of 400 mg/kg body wt./day for 2 weeks before and 4 weeks following carcinogen thread insertion. The cervical carcinoma incidence, as compared with that of the positive control (73%), was 23%. This decline in the incidence of carcinoma was highly significant (P less than 0.01). Hyperplastic and dysplastic changes did not show any definite correlation with the garlic treatment.

Modulation of 7,12-dimethylbenz[a]anthracene-induced transmammary carcinogenesis by disulfiram and butylated hydroxyanisole in mice

The individual as well as combined chemopreventive actions of disulfiram (DSF) and butylated hydroxyanisole (BHA) on 7,12-dimethylbenz[a]anthracene (DMBA)-induced transmammary carcinogenesis in mice were examined. When nursing mothers receiving normal diet were treated with DMBA (1 mg/mouse) on days 6, 8 and 10 postpartum, the tumor incidence in their 50-week-old F1 progeny was 44.1%. When nursing mothers receiving 0.75% BHA diet, 0.5% DSF diet and 0.75% BHA + 0.5% DSF diet were similarly treated with DMBA, the tumor incidences in their 50-week-old F1 progeny were 14.7% (P less than 0.05), 12.5% (P less than 0.05) and 5.8% (P less than 0.01), respectively. It is concluded that diets containing BHA (0.75%) and DSF (0.5%), singly or in combination, can inhibit transmammary carcinogenesis in Swiss albino mice.

Prognostic factors for recurrence and cosmesis in 393 patients after radiation therapy for early mammary carcinoma

Between 1978 and 1985, 393 of 2,765 (14%) patients with operable cancer of the breast (clinical stage T0-3N0-2M0) were irradiated after excisional biopsy and staging axillary dissection. Of 77 patients with microscopic axillary metastases, 68 received systemic adjuvant therapy. Treatment failed locally in 26 cases, and there were seven patients with distant metastasis. The three major factors for increased local treatment failure were (a) age below 40 years (P = .003), (b) negative estrogen receptor assay result (P = .03), and (c) failure to deliver a radiation boost dose when tumor was present at the margin of the specimen (P = .002). The size of the tumor, the nodal status, the progesterone receptor assay result, and the presence of ductal carcinoma in situ mixed with infiltrating carcinoma did not show a significant influence on local recurrence. In 274 of 393 (70%) patients, cosmesis was evaluated. The four major factors affecting cosmesis favorably were (a) utilization of a wedge (P less than .0001); (b) treatment of two fields a day (P less than .0001); (c) failure to use a separate treatment port to the regional lymph nodes, so as to avoid field junctions (P = .0003); and (d) small size of specimen (less than 50 cm2) (P = .0171). A second or third cancer was found in 39 of the 393 (10%) patients; contralateral breast cancer was the most common form (n = 23), followed by genitourinary cancer (n = 5). The most frequent complication was arm edema (6%).

Effects of mace (Myristica fragrans, Houtt.) on cytosolic glutathione S-transferase activity and acid soluble sulfhydryl level in mouse liver

The aril of plant Myristica fragrans Houtt. commonly known as mace, which is consumed as a spice as well as used as a folk-medicine, was screened for its effects on the levels of cytosolic glutathione S-transferase (GST) and acid-soluble sulfhydryl (SH) groups in the liver of young adult male and female Swiss albino mice. Animals were assorted into 4 groups comprised of either sex and received either normal diet (negative control), 1% 2,3-tert-butyl-4-hydroxyanisole (BHA) diet (positive control), 1% mace diet or 2% mace diet for 10 days. There was a significant increase in the GST activity in the liver of mice exposed to BHA or mace. In addition, there was a significant increase in the SH content in the liver of mice fed on 1% BHA and 2% mace diets.

Treatment selection for base of tongue carcinoma

Sixty-two previously untreated patients with squamous cell carcinoma of the base of tongue were retrospectively analyzed. The American Joint Committee on Cancer (AJCC) Stage distribution was I-3, II-7, III-24, and IV-28. The choice of treatment was nonrandomized. The local control was 10/18 with high-dose preoperative radiation, 17/30 with external beam radiation only, and 4/14 with external beam plus interstitial implantation. The median survival for the three treatment regimens were 63, 51, and 13 months, respectively. Preoperative radiation is suggested for tumors with inferior (laryngeal) spread or those with extensive superior extension (to tonsillar fossa and beyond). For centrally placed lesions in the base of the tongue (with or without lateral hypopharyngeal wall spread), radiation alone is recommended. An interstitial implantation should be restricted to lesions equal to or less than 4 x 3 x 2.5 cm3. Since this insertion is technically more demanding than for tumors of the mobile tongue, they should be performed by the more experienced brachytherapist.

Evaluation of the carcinogenicity of different preparations of areca nut in mice

Areca nut has been used as a masticatory since antiquity and it is estimated that more than 10% of the world population chews it in a variety of forms. We have evaluated the carcinogenicity of different preparations of areca nut: ripe-unprocessed-sundried nut (R-UP-SD), ripe-processed-sundried nut (R-P-SD), unripe-processed-sundried nut (UR-P-SD), ripe-unprocessed-sundried-water-soaked nut (R-UP-SD-WS) and ripe-unprocessed-undried-water-soaked nut (R-UP-UD-WS) in mice following diet-feeding or oral feeding for 12 months. Only unprocessed areca nuts (R-UP-SD, R-UP-SD-WS and R-UP-UD-WS), at high doses, displayed a very weak carcinogenicity.

Inhibitory action of dehydroepiandrosterone on methylcholanthrene-induced carcinogenesis in the uterine cervix of mouse

The present paper reports the chemopreventive action of Dehydroepiandrosterone (DHEA) on Methylcholanthrene- (MCA) induced carcinogenesis in the uterine cervices of adult virgin Swiss albino mice. Placement of sterile double cotton thread impregnated with beeswax containing 600 micrograms of MCA in the cervical canal produced tumors in 85.7% of mice in 16 weeks. When such carcinogen-containing threads were inserted into the uterine cervices of mice that were being fed on diets of 0.025%, 0.05% and 0.1% DHEA for a period of two preinsertion and sixteen postinsertion weeks, the cervical tumor incidences were reduced to 59.0%, 34.7% (P less than 0.01) and 14.2% (P less than 0.01), respectively. It is inferred that DHEA inhibits MCA-induced cervical carcinogenesis and the inhibitory action is dependent upon the dose of the drug.

Influence of arecoline on immune system: I. Short term effects on general parameters and on the adrenal and lymphoid organs

Arecoline, a suspected carcinogenic/cocarcinogenic alkaloid was screened to explore in detail its immunomodulatory influence in murine model system. The oral LD50 value for male mice was 371 mg/kg bw whereas it was 309 mg/kg bw for female mice. The subcutaneous LD50 value for both sexes was 97 mg/kg bw. Only a marginal difference was observed in intraperitoneal LD50 values between male (120 mg/kg bw) and female (109 mg/kg bw) mice. Arecoline was administered subcutaneously to male mice at subtoxic dose levels (5, 10, and 20 mg/kg bw) for 1, 2 and 3 weeks on a daily basis. In groups where significant decreases in body weight were present (at 20 mg/kg bw for both sexes), reductions in thymus weight were also noted. Spleen, mesenteric lymph nodes (MLN), liver, and kidney showed moderate reductions in their weights. Histopathological effects at 20 mg/kg bw included lymphocyte depletion of the thymic cortex, and the B and T lymphocyte areas in spleen and MLN. In concordance with the zona fasciculata hypertrophy of adrenals, corticosterone concentration in serum increased depending on the dose with a significant elevation at 20 mg/kg bw. While total protein, albumin, glucose, acid phosphatase and hemoglobin concentrations were not altered, increases in SGOT and SGPT levels were observed at the high dose. The white and red blood cell counts decreased in a dose-dependent manner. Marked reduction in cell number of thymus, and moderate effect on cellularity of spleen and MLN, were observed at 20 mg/kg bw. In vitro exposure of rat thymocytes to arecoline resulted in a biphasic oxygen consumption response with progressive increase in oxygen consumption, reaching a maximum value at 10(-5) M and decreasing sharply at 10(-3) M. Exogenously added substrates such as glucose, pyruvic acid and lactic acid retarded the fall in the oxygen consumption induced at 10(-3) M arecoline. These observations demonstrate the effects of arecoline on lymphoid organs, which may be due to its direct action or through the elevation of corticosterone.

Modulatory influences of exogenous estrogen on MCA-induced carcinogenesis in the uterine cervix of mouse

Placement of cotton-thread impregnated with beeswax containing methylcholanthrene (approx. 600 micrograms) inside the canal of uterine cervix of virgin adult mice results in the emergence of precancerous and cancerous lesions in the cervical epithelium. Employing this experimental cervical carcinogenesis model system, the present study evaluates the modulatory influence of exogenous 17 beta-estradiol on the incidences of precancerous and cancerous lesions in the cervical epithelium. When 17 beta-estradiol was administered weekly at the dose levels of 0.01 microgram, 0.1 microgram, 5 micrograms and 50 micrograms for 16 weeks following carcinogen-thread insertion, the cervical carcinoma incidences, as compared to that in positive control mice (76.1%), were 66.6%, 61.5%, 55.5% and 42.1%, respectively. The decline in the incidence of carcinomas at 50 micrograms/week dose level was significant (P less than 0.05). Hyperplastic and dysplastic changes did not show any definite correlation with the various treatments.

Modulation of methylcholanthrene-induced carcinogenesis in the uterine cervix of mouse by indomethacin

The present paper reports the chemopreventive action of indomethacin on methylcholanthrene (MCA)-induced carcinogenesis in the uterine cervix of virgin young adult Swiss albino mice. Placement of a sterile cotton thread impregnated with beeswax containing approx. 600 micrograms of MCA produces cervical tumors in 91% mice in 16 weeks. When such carcinogen-containing threads are inserted into the uterine cervix of mice fed diets containing indomethacin at the dose levels of 10 mg/kg, 20 mg/kg and 40 mg/kg diet for two pre-insertion weeks plus 16 post-insertion weeks, the cervical tumor incidences were 83%, 65% and 26% (P less than 0.01), respectively. It is concluded that indomethacin, when given in the diet at sufficiently high concentration, significantly inhibits MCA-induced cervical carcinogenesis.

Inhibitory action of garlic oil on the initiation of benzo[a]pyrene-induced skin carcinogenesis in mice

When garlic oil was topically applied during the initiation phase of benzo[a]pyrene (B(a)P)-induced skin carcinogenesis in random bred adult female Swiss albino mice of two different substrains, there was a decline in the number of tumor-bearing mice as well as in the mean number of tumors per effective mouse.

Application of Folin-Ciocalteu reagent for the spectrophotometric determination of some nonsteroidal antiinflammatory agents

A simple, sensitive, accurate, and rapid method for the quantitative determination of naproxen, oxyphenbutazone, mefenamic acid, indomethacin, and diclofenac sodium in pharmaceutical preparations is proposed. The method is based on the formation of blue complexes with Folin-Ciocalteu reagent.

Observations on the treatment of mediastinal masses in Hodgkin's disease emphasizing site of failure

Of 244 patients with Hodgkin's disease, 126 (52%) had an abnormal mediastinum. Sixty-four patients were treated with radiation, 36 with radiation and chemotherapy, and 25 with chemotherapy alone as an initial treatment. Twenty of 52 (38%) with stage I or II who received initially radiation alone relapsed, and 70% (14 of 20) of them were salvaged with chemotherapy. Therefore, the ultimate failure rate was 12% (6 of 52). Forty percent (8 of 20) of these patients failed within or at the margin of the radiation portal, and 60% failed predominantly outside of the radiation field. Even though we did not treat the whole lung prophylactically, there was only one true peripheral lung recurrence. Nine of 20 (45%) recurred in more than one site. Of 36 patients treated with combined radiation and chemotherapy, 21 patients had stage I, II, or IIIA disease. Of these, two patients relapsed. Of 86 patients with accessible x-ray films, 30 patients had large masses with a ratio of mass to transverse diameter greater than .33 at the broadest level. Fifty-six patients had small masses. Survival at 96 months in patients with stages I-IIIA with either large or small masses is 94% (p = 0.80). Their relapse-free survival at 96 months is 79% for large masses and 95% for small masses (p = 0.18). The site of relapse is discussed in detail in the text. There were five treatment-related deaths; three patients died of acute myelogenous leukemia. Our data do not support the role of whole-lung prophylactic irradiation or initial combined radiotherapy and chemotherapy in patients with large mediastinal masses.

Proposed method to study the factors affecting local control with combined external beam and interstitial implantation of mobile tongue and floor of mouth

Twenty-seven patients with squamous cell carcinoma of the mobile tongue and floor of the mouth were treated with external beam and interstitial radiation. Good prognostic factors were T1N0, T2N0, superficial tumors, tumor shrinkage by 75% with external beam, and no apparent tumor clinically 2 months after treatment. On the other hand, T3N0, T1-3N1, and deeply necrotic tumors had a poor prognosis. We recommend using a flexible afterloading system to implant the initial local tumor volume (not just the residual nidus) that does not exceed 45 cm3. The minimum (reference) dose was prescribed to a surface 1/2 cm beyond the most peripheral rim of radioactive sources. For acceptable local control and complication rates, our suggested minimum (reference) doses are less than or equal to 7,500 rads for T1 (or a time-dose-fractionation [TDF] of 131-140), less than or equal to 8,000 rads for T2 (TDF of 131-140), and probably less than 8,500 rads for T3 (TDF of less than or equal to 150). These guidelines should be considered preliminary.

Effect of glycerol level in Tris-basek extender and equilibration period on quality of frozen goat semen

Twenty ejaculates, 4 from each of 5 native goats, were collected using an artificial vagina, and the effects of glycerol level (4, 6.4 and 9 %) and the equilibration period (1, 3 and 5 h) were studied by split-sample technique. The extender used was Tris egg yolk citric acid fructose glycerol extender. The semen was frozen in 0.5-ml French straws by exposure for 10 min to liquid nitrogen vapor, 5 cm above the liquid nitrogen level. After 14 h of storage in liquid nitrogen, the straws were thawed in water at 37 degrees C for 12 - 15 sec. The percentage of progressively motile sperm (PPM) and the percentage of damaged acrosomes (PDA) were studied after equilibration and after thawing. The mean PPM after thawing was found to be 64.0 +/- 0.90, 66.92 +/- 0.54 and 63.65 +/- 1.07 when semen was frozen with 4, 6.4 and 9 % glycerol and 61.48 +/- 0.81, 65.05 +/- 0.78 and 68.03 +/- 0.87 in 1-, 3- and 5-h equilibrated semen, respectively. The mean PDA after thawing was 7.12 +/- 0.88, 8.23 +/- 0.76 and 10.58 +/- 0.84 when semen was frozen with 4, 6.4 and 9 % glycerol and 7.0 +/- 0.74, 9.0 +/- 0.95 and 9.93 +/- 0.81 in 1-, 3- and 5-h equilibrated semen, respectively. Both PPM and PDA differed significantly (P<0.01) between glycerol levels, between equilibration periods and between stages (after equilibration and after thawing). The PPM also differed significantly due to equilibration period x stage interaction (P<0.01) and glycerol level x stage interaction (P<0.05). The PDA did not differ significantly due to interactions. When the differences between pairs of means were tested by least significant difference, it was found that after equilibration PPM was not significantly affected by either glycerol level or equilibration period, while after thawing, it was significantly higher (P<0.05) for 6.4 % glycerol and 5-h equilibrated semen than for 4 or 9 % glycerol and 1- or 3-h equilibrated semen, respectively. The PDA was lower with 4 % glycerol and 1-h equilibrated semen.

Study of the genotoxicity of the total aqueous extract of betel nut and its tannin

Frequencies of sister-chromatid exchanges (SCEs) were measured to study the genotoxicity of the total aqueous extract of betal nut and its tannin on mouse bone-marrow cells in vivo. Betal nut aqueous extract and tannin were injected i.p. into mice at doses of 12.5, 25 or 50 micrograms/g body weight and 50, 100 or 200 micrograms/g body weight respectively for 5, 10 or 15 days. Betal nut extract induced a dose-related increase in the frequency of SCEs after five daily doses of 12.5, 25 or 50 micrograms. Significant increases in SCEs were also observed in animals dosed for 10 days with 50 micrograms/g and for 15 days with 25 or 50 micrograms/g extract. After five daily doses of 50, 100 or 200 micrograms/g of betel nut tannin there was no significant induction of SCE. Mice dosed with 200 micrograms/g tannin for 10 days, or 100 or 200 micrograms/g for 15 days, showed significant increases in the frequency of SCEs.

Transplacental micronucleus inducing ability of arecoline, a betel nut alkaloid, in mice

Arecoline, a major betel nut alkaloid, was tested for its effectiveness in inducing micronuclei in fetal mouse blood after transplacental exposure late in the gestation period. Positive results were obtained and a linear dose-response relationship was expressed when pregnant mice were treated with arecoline at dose levels of 20, 40 and 80 mg/kg and micronucleated polychromatic erythrocytes from fetal blood were subsequently analysed.

Induction of shape abnormality and unscheduled DNA synthesis by arecoline in the germ cells of mice

The ability of arecoline, an alkaloid of betel nut, to induce abnormality in the shape of sperm heads and unscheduled DNA synthesis (UDS) in the early spermatid stages of Swiss albino mice was studied. Treatment of mice with arecoline at the dose levels of 20, 40 and 80 mg/kg elicited dose-related increase in the number of abnormal sperm heads, as well as the unscheduled incorporation of [3H]thymidine into the DNA of early spermatids. Such increase in the production of abnormally shaped sperms and UDS response of the early spermatids following arecoline treatment expressed its genotoxic potential in the mouse germ cells.

Embryotoxicity of betel nuts in mice

The fetotoxic potential of betel nuts was investigated in Swiss albino mice. Total aqueous extracts of ripe betel nuts of unprocessed and processed varieties were administered to pregnant animals at dose levels of 1, 3 and 5 mg/day/mouse (27 +/- 1 g body wt) through days 6-15 of gestation. The dams were sacrificed prior to term and the fetuses were examined for morphological, visceral and skeletal anomalies. The treatments resulted in increased resorptions as well as dead fetuses. Fetal weight was adversely affected as indicated by the dose related reduction in average body weight of live fetuses. No major morphological, visceral and skeletal defects, apart from hematomas, curved tails and a few incidences of rib anomalies, were observed. There was, however, a dose-related decrease in the number of fetuses possessing ossified coccygeal vertebrae while an increase in the number of fetuses with unossified 5th metacarpals. This indicated a delay in skeletal maturity, particularly in those fetuses exposed prenatally to the betel nut extract of the unprocessed variety.

Radiomodifying effect of camphor on the spermatogonia of mice

Camphor has been reported to exhibit radiomodifying properties for bacteria and solid tumours of mice. Therefore its radiomodifying effect was evaluated in the testis which is a less vascularised and hypoxic tissue. Young adult strain 'A' male mice were taken up for these studies. Camphor was administered at the rate of 0.1 mg/g body weight intraperitoneally and whole body irradiation was done after 45 minutes under normal aerated conditions. Doses of 0.5, 1.0 and 2.0 Gy were delivered to different groups with the help of 60Co gamma cell. Testicular germ cell renewal system which seems to be a very good model system for the study of chemical radiomodifier was used for this assay. Resting primary spermatocytes (RPS) were counted at different time intervals and comparison was made among different treatment groups and controls. It was observed that RPS counts significantly declined in radiation + camphor treated groups in comparison to radiation alone or control groups. Radiomodifying effect of camphor was significantly evident during the recovery period, i.e., on day 8 after 0.5 Gy irradiation and day 6 onward after 1.0 Gy and 2.0 Gy.

Inhibitory action of Piper betle on the initiation of 7,12-dimethylbenz[a]anthracene-induced mammary carcinogenesis in rats

When an aqueous extract of the leaves of Piper betle, a medicinal plant, was given orally at different dose levels during the initiation phase of 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary carcinogenesis in rats, higher doses of the extract inhibited the emergence of tumors. However, when the extract was fed to the rats bearing DMBA-induced mammary tumors for 8 weeks, no appreciable degree of inhibition of tumor growth was noticed. Betel leaf extract at the dose levels used in the present study did not affect the body weight gain among rats.

Inhibitory action of aminoglutethimide on DMBA-induced mammary carcinogenesis

The present communication reports the inhibitory action of aminoglutethimide on 9,10-dimethyl-1,2-benzanthracene (DMBA) induced mammary carcinogenesis in virgin female Holtzman rats. When 20 mg of DMBA is given to the rats and maintained on normal diet for 32 weeks, approximately 70% of the animals develop mammary tumors. When animals similarly treated with DMBA are put on diets containing 0.025%, 0.05%, and 0.1% of aminoglutethimide for 32 weeks, there is a decline in the number of tumor-bearing animals as well as in the number of tumors per tumor-bearing animal, especially at higher diet doses of the drug. This inhibitory action on the induction of mammary tumors by DMBA could be mainly due to the suppressive action of the drug on endocrine functions.

Reassessment of technical and biological factors in paranasal sinus carcinoma

Twenty-seven patients with paranasal sinus carcinoma were analyzed. Local control with radiation alone was poor, with most patients failing centrally within the primary site. With preoperative radiation local control is 60%. Previous reports have emphasized failure at superior sites--particularly the orbit. The pattern of local failure in our series is predominantly various medial sites inclusive of intact or exenterated orbit. The surgically nonremovable medial structures are best encompassed by a three-field radiotherapy technique (weighted anterior and two laterals).

Management of gastrointestinal lymphoma

A study was made of 65 patients with primary gastrointestinal (GI) lymphoma. The occurrence was 40 (62%) in stomach, 15 (23%) in the small intestine, and 10 (15%) in colorectum. The majority of patients had their histology classified according to Rappaport's classification. Diffuse histiocytic type had the worst prognosis (median survival 13.8 months), and nodular histology had the best prognosis. A modified staging system proposed by Blackledge et al. was used. Patients who had their disease confined to one viscus (Stage I) or with spread to regional lymph nodes (Stage II) had an excellent prognosis, with a 5-year survival of 87 and 67%, respectively. However, those who had distant nodal involvement (Stage III, e.g., para-aortic nodes) or spread to adjacent organs within the abdomen (Stage IV) had worse prognosis, with 5-year survival of 40 and 13%, respectively. In Stage I, radiotherapy alone was as effective as surgical resection. None of the 11 patients treated by radiotherapy alone had perforation or bleeding. The 5-year disease-free survival was 51%.

Induction of in vivo sister chromatid exchanges by arecaidine, a betel nut alkaloid, in mouse bone-marrow cells

The genotoxicity of arecaidine, an alkaloid of betel nut, was studied on mouse bone marrow cells in vivo by sister chromatid exchange (SCE) method. Arecaidine was administered intraperitoneally to mice at the dose levels of 2.5 mg, 5 mg and 7.5 mg to each mouse weighing 25 +/- 1 g for 5, 10 and 15 days. Significant increase in the number of SCEs was observed in the treated groups, and this increase, although dose-dependent, was not dependent upon the duration of exposure.

Modifying influences of betel quid ingredients on B(a)P-induced carcinogenesis in the buccal pouch of hamster

The present study evaluates the incidence of tumors in hamster buccal pouches following short-term (10 days) and long-term (6 months) topical exposures to graded doses of benzo(a)pyrene, B(a)P (25 micrograms, 50 micrograms and 100 micrograms per pouch either daily for 10 days or thrice weekly for 6 months) alone or in combination with extract of tobacco (1 mg/pouch, twice daily), betel nut (1 mg/pouch, twice daily) or betel leaf (5 mg/pouch, twice daily). Given alone, the three doses of B(a)P respectively yielded, 6 months after the last treatment, 4%, 8.7% and 16.7% tumors in the short-term study, and 20%, 35% and 61% tumors in the long-term study. Short-term treatments with individual ingredients of betel quid did not produce any tumors while long-term treatments produced tumors only with tobacco (17.6%) and betel nut (10.5%). When B(a)P, and betel quid ingredients were painted concomitantly for 10 days, there was, depending upon the dose of B(a)P, complete or partial suppression of tumor production. But when B(a)P-plus-tobacco or B(a)P-plus-betel nut treatments were given for 6 months, there was a considerable increase in tumor incidence. Betel leaf extract, in both short-term and long-term studies, expressed its inhibitory influence on B(a)P-induced tumorigenesis.

Influence of 2-mercaptopropionylglycine on DMBA-induced biochemical changes in regenerating mouse liver: I. Key enzymes of glycolysis and lactate dehydrogenase

When the chemical carcinogen, DMBA, is administered by intragastric intubation to young adult female mice already subjected to partial hepatectomy, the glycolytic key enzymes (hexokinases, phosphofructokinase, pyruvate kinase) and lactate dehydrogenase show declined levels in the regenerating liver. But concomitant administration of MPG, a hepatotropic detoxicant, with DMBA either nullifies or minimizes the effect of the carcinogen on these enzymes.

Influence of caffeine on arecoline-induced SCE in mouse bone-marrow cells in vivo

The effect of exposure of mice for 5, 10 and 15 days to arecoline or/and caffeine on the frequency of sister-chromatid exchanges (SCEs) in bone-marrow cells was evaluated by using the fluorescence plus Giemsa technique. There was a significant increase in the frequency of SCEs after exposure to either arecoline or caffeine. When these two alkaloids were given in combination, the SCE frequency-enhancing effect was additive. The implications of coffee/tea drinking and betel chewing on oral cancer are discussed.

Influence of 2-mercaptopropionylglycine on DMBA-induced biochemical changes in regenerating mouse liver: II. Glucose-6-phosphate dehydrogenase, malic enzyme DNA, and protein

Present investigation documents the influence of 2-mercaptopropionylglycine, a hepatropic detoxicant, on glucose-6-phosphate dehydrogenase, malic enzyme, DNA, and total protein contents in regenerating mouse liver exposed to a chemical carcinogen--DMBA. DMBA, when given alone, decreases the levels of these macromolecular constituents in the regenerating liver. When MPG is given with DMBA, the levels of these, except that of G6P-DH, are maintained at control levels.

Glyoxalase I in regenerating mouse liver exposed to carcinogens

Glyoxalase I is the first component of glyoxalase system which is involved in detoxification of alpha-ketoaldehydes and converts them to nontoxic substances. This study reports changes in Glyoxalase I activity in relation to DNA synthesis in regenerating liver treated with two polycyclic aromatic hydrocarbons - 7,12-dimethylbenz (a) anthracene and benzo(a)pyrene. Livers after partial hepatectomy show consistent increase in Gly. I which reaches to its peak at 24 hr after surgery. [3H]Thymidine incorporation into DNA also follows the same trend as does Gly. I in regenerating liver. Both the carcinogens have significantly reduced the activity of Gly. I and DNA biosynthesis when compared with untreated partially hepatectomized control livers. The study reveals that though regenerating liver has been considered as an experimental model for neoplasia, unlike tumors (where Gly. I is either absent or in undetectable quantities) it possesses more Gly. I than in normal liver. On the other hand, preneoplastic liver during initiation (in regenerating liver treated with carcinogens, initiation is expected to occur) has very low activity. This suggests that Gly. I is not only involved in controlling growth but possibly is involved in some other phenomenon which is somehow depressed in preneoplastic and cancerous tissues.

Local control of T1 vocal cord cancer with radiation therapy: the importance of tumor character vs. treatment parameters

Ninety-one patients with T1 vocal cord carcinoma received primary irradiation treatment. The 5- and 10-year determinate disease-free survival was 80%; the 5- and 10-year determinate survival including surgical salvage was 92%. Tumors involving more than one-half of a vocal cord or involving the anterior commissure or exhibiting an exophytic growth pattern had numerically, but not statistically, higher local failure rates than tumors without these characteristics. Precise radiation treatment technique appears more important for local control (LC) than tumor character. The crucial treatment factors for high LC with few radiation complications are reproducible daily patient positioning, use of contour-compensating devices (wedges), field size of 5 X 5 cm, and a radiation prescription with a time-dose fractionation value of 101 to 106.

Chromosome-breaking ability of arecoline, a major betel-nut alkaloid, in mouse bone-marrow cells in vivo

The chromosomal damaging properties of arecoline, a major betel-nut alkaloid were investigated in vivo after its administration to mice. Arecoline was injected in doses of 0.25, 0.5, 1 and 2 mg for 10, 20 and 30 days each. Significant numbers of aberrations were observed in the form of chromatid breaks, chromosome breaks, ring structure, multiple breaks and cells with pulverized chromosomal complements. The frequency of aberrations showed a dose-response relationship. So arecoline was concluded to have weak chromosome-damaging effects in vivo.

A 'watchful waiting' policy for in situ carcinoma of the vocal cords

Forty-five patients with vocal cord (VC) carcinoma in situ diagnosed by biopsy or VC stripping have been retrospectively analyzed. Eighteen patients received irradiation therapy immediately on diagnosis. The initial local control (LC) rate was 72% (13/18); the salvage-augmented LC rate was 94% (17/18). Twenty-seven patients with in situ carcinoma were treated expectantly ("watchful waiting"), receiving definitive radiotherapy or definitive surgery only if invasion was subsequently verified histologically. One third of the patients' carcinomas have not become invasive (mean follow-up, 50 months). Of the two thirds that became invasive, one third were more advanced than T1N0 when treated--often because patients missed scheduled follow-up appointments. Nevertheless, the initial LC rate was 65% (11/17); the salvage-augmented LC rate was 88% (15/17). Total laryngectomy was required twice as often in the watchful waiting group as in the immediately treated group.

Patterns of recurrence following curative resection alone for adenocarcinoma of the rectum and sigmoid colon

Two-hundred-four patients with previously untreated adenocarcinoma of rectum, rectosigmoid, and sigmoid colon were retrospectively evaluated to determine patterns of recurrence following curative resection. Seventy-eight (38%) subsequently developed recurrent disease. Of these, 40% (31/78) presented with local recurrence alone, 28% (22/78) with regional recurrence, 15% (12/78) with concomitant local recurrence and distant metastasis, and 17% (13/78) with distant metastasis alone. The degree of tumor anaplasia and depth of tumor penetration into the bowel wall influenced the rate of local recurrence. Through five years local recurrence without clinical evidence of distant metastasis was the most common cause of death. Need for adjuvant radiation therapy is discussed.

Patterns of recurrence following curative resection alone for adenocarcinoma of the rectum and sigmoid colon

Two-hundred-four patients with previously untreated adenocarcinoma of rectum, rectosigmoid, and sigmoid colon were retrospectively evaluated to determine patterns of recurrence following curative resection. Seventy-eight (38%) subsequently developed recurrent disease. Of these, 40% (31/78) presented with local recurrence alone, 28% (22/78) with regional recurrence, 15% (12/78) with concomitant local recurrence and distant metastasis, and 17% (13/78) with distant metastasis alone. The degree of tumor anaplasia and depth of tumor penetration into the bowel wall influenced the rate of local recurrence. Through five years local recurrence without clinical evidence of distant metastasis was the most common cause of death. Need for adjuvant radiation therapy is discussed.