The effect of alfalfa-corn diets on cholesterol metabolism and gallstones in prairie dogs

Cholesterol gallstones were present in prairie dogs fed alfalfa plus corn with and without exogenous cholesterol (0.4%). The diets fed to the animals for eight weeks contained alfalfa plus corn in fixed proportions of 50:50, 85:15 and 15:85 (w/w). At sacrifice, all animals were healthy but had not gained weight; no deaths occurred during the experiment. Cholesterol gallstones were present in all groups. In the absence of exogenous cholesterol, the highest stone incidence was found in the animals which received the lowest fiber (highest corn) diets (alfalfa plus corn, 50:50, 67%; alfalfa plus corn, 15:85, 83%). Cholesterol gallstone incidence was 100% when exogenous cholesterol was added to the alfalfa plus corn diets (50:50 and 15:85). No pigment gallstones were detected in any animal. Liver and plasma cholesterol concentrations were highest in the animals receiving alfalfa plus corn (15:85) plus 0.4% cholesterol (4.29 mg/g, and 356 mg/dl, respectively). These values were lowest in animals receiving 85% alfalfa plus 15% corn without cholesterol (2.19 mg/g and 88 mg/dl, respectively). Lithogenic indices were below 1.00 in all groups. Biliary bile acids were mainly amidates of cholic acid and chenodeoxycholic acid, with the former predominating. Thus, gallstones can be formed in prairie dogs in the absence of exogenous cholesterol; gallstone incidence is reduced by dietary fiber.

Bile acids substituted in the 6 position prevent cholesterol gallstone formation in the hamster

The aim of the present study is to examine the efficacy of 6-hydroxy substituted bile acids on the prevention of cholesterol gallstones in a new hamster model of cholesterol cholelithiasis. Male golden Syrian hamsters were fed a nutritionally adequate semipurified lithogenic diet consisting of casein, cornstarch, soluble starch, butterfat, corn oil, and cellulose plus 0.3% cholesterol. Six different bile acids were added to this diet at the 0.05% level: chenodeoxycholic acid, ursodeoxycholic acid, hyodeoxycholic acid, murideoxycholic acid, 6 beta-methyl-hyodeoxycholic acid, and 6 alpha-methyl-murideoxycholic acid. At the end of the 6-wk feeding period, the control group receiving the lithogenic diet had a 55% incidence of gallstones. It was found that all bile acids had inhibited the formation of cholesterol gallstones; complete prevention of gallstones was observed with all 4 3,6-dihydroxy bile acids, whereas chenodeoxycholic acid and ursodeoxycholic acid were somewhat less effective (80% and 75% prevention, respectively). The accumulation of cholesterol in serum and liver induced by the lithogenic diet was inhibited to some extent by all of the bile acids; hyodeoxycholic acid, murideoxycholic acid, and 6 beta-methyl hyodeoxycholic acid were most effective in this respect. The administered bile acids tended to predominate in bile in the case of chenodeoxycholic acid, hyodeoxycholic acid, and 6 beta-methyl-hyodeoxycholic acid. In contrast, ursodeoxycholic acid seemed to be converted to chenodeoxycholic acid and murideoxycholic acid to hyodeoxycholic acid. Only 4% of the 6-methyl analogue of murideoxycholic acid, 6 alpha-methyl-murideoxycholic acid, was recovered in gallbladder bile. These experiments show that the new hamster model of cholesterol cholelithiasis is suitable for gallstone-prevention studies. It was not possible to draw definite conclusions concerning the mechanism of action of the administered bile acids on the basis of cholesterol saturation or the presence of liquid crystals. The detailed mechanism of gallstone prevention by hydrophilic bile acids in this model remains to be elucidated.

Effects of calcium and bile acid feeding on colon tumors in the rat

The hypothesis that dietary calcium alters the incidence of colorectal neoplasms was examined in an established model of carcinogenesis. Male Fischer 344 rats (28 days old) were quarantined for 2 weeks. All animals were fed the basal diet (AIN-76) supplemented with cholic acid (0.2%) and/or calcium (1.6%, corresponding to a 3-fold increase above that of the basal diet). N-Methyl-N-nitrosourea (MNU) (2 mg/dose) or saline (control) was given intrarectally to all animals on days 1 and 4 of the experiment. Groups 1-8 were fed the experimental diets concurrently with the first dose of MNU, while groups 9 and 10 were fed the diets 2 weeks prior to MNU (or saline). All animals were sacrificed after 28 weeks. No tumors were observed in the groups given saline (groups 1, 3, 5, 7, and 9). In groups receiving MNU, the addition of cholic acid to the diet (group 4) caused a significant increase in tumors (80% versus 55%), tumors/animal ratio (2.24 versus 0.75), and tumors/tumor-bearing animal ratio (2.80 versus 1.36), group 4 versus group 2, respectively. Increased dietary calcium did not inhibit tumor formation; 68% of animals in groups 6 and 10 had tumors. The combination of dietary cholic acid and calcium (group 8) gave a tumor incidence similar to cholic acid (group 4) alone (72% versus 80%, 2.00 versus 2.24 tumors/animal; 2.77 versus 2.80 tumors/tumor-bearing animal). Most tumors were adenomatous polyps but carcinomas in situ and invasive carcinomas were also present; dietary calcium reduced the number of invasive carcinomas (group 6 versus group 2, P less than 0.04).

Comparison of serum assays for TAG-72, CA19-9 and CEA in gastrointestinal carcinoma patients

Tumor-associated glycoprotein (TAG-72) has been shown to be expressed in a wide variety of epithelial malignant tissues. We have investigated serum levels of TAG-72 antigen in patients with gastrointestinal cancer with a solid phase radioimmunometric assay (RIA), CA72-4, utilizing murine monoclonal antibodies CC49 and B72.3 which recognize the TAG-72 antigen. Elevated levels of serum TAG-72 antigen were found in 48% of 56 gastric carcinoma patients and 67% of 45 colorectal carcinoma patients. The serum concentrations of TAG-72 were compared to those of CA19-9 and CEA. The positive rates of CA19-9 in gastric carcinoma and colorectal carcinoma patients were 29% and 54%, and those of CEA were 52% and 60%, respectively. Elevated serum levels of TAG-72, CA19-9 and CEA were observed in 7%, 14% and 24%, respectively, of patients with benign disease, thus indicating a preferential expression of TAG-72, compared to CA19-9 and CEA, in gastrointestinal carcinoma patients versus in patients with benign disorder. A cocktail of CA72-4, CA19-9 and CEA RIAs increased positive rates to 68% in sera of gastric cancer patients and 84% in sera of colorectal cancer patients. Combination assays using CA72-4, CEA and CA19-9 RIAs for patients with benign gastrointestinal disorder, however, also increased the positive rate to 31%. These results indicate that CA72-4, CA19-9 and CEA RIAs may be complementary in detecting circulating tumor-associated antigens. It must be emphasized, however, that interpretation of the data provided by the combination serum assays requires careful consideration.

Synthesis of new bile acid analogues and their metabolism in the hamster: 3 alpha, 6 alpha-dihydroxy-6 beta-methyl-5 beta-cholanoic acid and 3 alpha, 6 beta-dihydroxy-6 alpha-methyl-5 beta-cholanoic acid

This paper reports the chemical synthesis of two new bile acid analogues, namely, 3 alpha, 6 beta-dihydroxy-6 alpha-methyl-5 beta-cholanoic acid from 3 alpha-hydroxy-6-oxo-5 beta-cholanoic acid and describes their metabolism in the hamster. A Grignard reaction of the oxo acid with methyl magnesium iodide in tetrahydrofuran gave two epimeric dihydroxy-6-methyl-cholanoic acids which were separated as the methyl esters by silica gel column chromatography. The configuration of the 6-methyl groups was assigned by proton nuclear magnetic resonance spectroscopy and was supported by the chromatographic properties of the new compounds. The metabolism of the two new bile acid analogues was studied in the hamster. After intraduodenal administration of the 14C-labeled analogues into bile fistula hamsters, both compounds were absorbed rapidly from the intestine and secreted into bile. Intravenous infusion studies revealed that these compounds were efficiently extracted by the liver; the administered analogues became major biliary bile acids, present as either the glycine or taurine conjugates. These compounds are useful to study the effect of methyl-substituted bile acids on cholesterol and bile acid metabolism and may possibly possess cholelitholytic properties.

Cholelithiasis in hamsters: effects of cholic acid and calcium on gallstone formation

Dietary cholic acid (0.1%) and/or calcium (2.6% as calcium carbonate) were added to a semipurified diet containing cholesterol and ethynyl estradiol to determine whether the incidence of pigment and/or cholesterol gallstones would be changed. Male golden Syrian hamsters were fed the experimental diets for 96 days (Group 1, control; Group 3, cholic acid plus calcium) or only an average of 60 days (Group 2, 0.1% cholic acid). Animals in Group 2 became ill (weight loss, low food intake, diarrhea) possibly due to cholic acid (or deoxycholic acid) toxicity. Cholesterol gallstones and crystals were absent in all experimental groups. The incidence of pigment gallstones was: control, Group 1, 12/16; 0.1% cholic acid, Group 2, 3/13; and 0.1% cholic acid plus calcium, Group 3, 11/22. Cholic acid with or without calcium produced an elevation of both liver and plasma cholesterol: Group 2, 80.1 mg/g and 501 mg/dl; Group 3, 103.7 mg/g and 475 mg/dl vs Group 1, 65 mg/g and 209 mg/dl, respectively. The lithogenic indices of the bile were lower in Groups 2 and 3 compared to Group 1, controls, 0.45 and 0.58 vs 1.16, respectively. The extent of the portal tract pathology could not be correlated with the presence or absence of pigment gallstones or with the levels of lithocholic acid in the hamster bile. In summary, when semipurified diets were supplemented with ethynyl estradiol and cholic acid, with and without calcium supplementation, no cholesterol gallstones formed and the incidence of pigment gallstones was not altered.

Dietary induction of cholesterol gallstones in hamsters from three different sources

Cholesterol gallstones were produced in young male, golden Syrian hamsters, obtained from three different suppliers, by administering a nutritionally adequate, semipurified diet for periods of either 5 or 10 weeks. The major components of the lithogenic diet were casein, cornstarch, butterfat, corn oil and 0.3% cholesterol. The hamsters were obtained from Sesco, Harlan Sprague-Dawley (Engle hamster) and Charles River (Lakeview hamster). There were profound differences among the three groups with respect to gallstone formation and cholesterol metabolism: The highest incidence of gallstones occurred in Sesco hamsters, 44.4% and 63.6% after 5 and 10 weeks on the lithogenic diet, respectively. In the Engle hamster, after a 5-week feeding, cholesterol crystals and gallstones were absent. When the feeding period was extended to 10 weeks, cholesterol gallstones were present in 45.5% of the animals. In the Lakeview hamsters, neither gallstones nor cholesterol crystals were found in the gallbladder after a 5-week period. After 10 weeks, cholesterol gallstones were found in only a single hamster. In all groups, the lithogenic diet produced large increases of liver, serum and biliary cholesterol concentrations and increased liver weights. When the animals were fed for 5 weeks, only the bile of Sesco hamsters became supersaturated. Supersaturated bile was induced in all groups after a 10-week feeding of the lithogenic diet with cholesterol saturation ranging from 1.47 to 1.97. These data indicate that it is possible to induce cholesterol gallstones in hamsters by means of a nutritionally adequate, semipurified diet of moderate cholesterol content.(ABSTRACT TRUNCATED AT 250 WORDS)

7-Methyl bile acids: effects of chenodeoxycholic acid, cholic acid, and their 7 beta-methyl analogues on the formation of cholesterol gallstones in the prairie dog

The purpose of this study was to compare the effects of the naturally occurring bile acids (chenodeoxycholic acid and cholic acid) with their 7-methyl analogues (3 alpha,7 alpha-dihydroxy-7 beta-methyl-5 beta-cholanoic acid and 3 alpha,7 alpha,12 alpha-trihydroxy-7 beta-methyl-5 beta-cholanoic acid) on gallstone formation and prevention and cholesterol metabolism in the prairie dog. Sixty animals were fed a semipurified diet, containing 0.4% cholesterol, with one of the following acids (0.1%): chenodeoxycholic, cholic, 3 alpha,7 alpha-dihydroxy-7 beta-methyl-5 beta-cholanoic, or 3 alpha,7 alpha,12 alpha-trihydroxy-7 beta-methyl-5 beta-cholanoic acid. This concentration of dietary bile acids amounts to a dose of 27-30 mg/kg.day. After 8 wk, 89% of control animals had gallstones and 94% had cholesterol crystals. Chenodeoxycholic and 3 alpha,7 alpha-dihydroxy-7 beta-methyl-5 beta-cholanoic acids decreased the incidence of gallstones to 50%. Cholic acid and 3 alpha,7 alpha,12 alpha-tri-hydroxy-7 beta-methyl-5 beta-cholanoic acid did not prevent gallstone formation. The liver cholesterol level was decreased by chenodeoxycholic acid, whereas cholic and 3 alpha,7 alpha,12 alpha-trihydroxy-7 beta-methyl-5 beta-cholanoic acids increased serum and liver cholesterol. Each administered bile acid became the predominant biliary bile acid and 7-methyl analogues did not increase secondary bile acids. Fecal analysis of radioactive metabolites using 14C-labeled 7-methyl analogues showed that these compounds are resistant to bacterial 7-dehydroxylation. It was concluded that 3 alpha,7 alpha-dihydroxy-7 beta-methyl-5 beta-cholanoic acid inhibited gallstone formation as effectively as chenodeoxycholic acid, whereas both cholic and 3 alpha,7 alpha,12 alpha-trihydroxy-7 beta-methyl-5 beta-cholanoic acids were not effective. The effects of 7-methyl analogues on the parameters of cholesterol metabolism that we studied were similar to those of their parent compounds, chenodeoxycholic and cholic acids. Thus, 3 alpha,7 alpha-dihydroxy-7 beta-methyl-5 beta-cholanoic acid but not 3 alpha,7 alpha,12 alpha-trihydroxy-7 beta-methyl-5 beta-cholanoic acid offers promise in cholelitholytic therapy for the prevention and possibly dissolution of cholesterol gallstones.

[A radioimmunometric assay for circulating tumor-associated glycoprotein (TAG-72) using the antigen determinant CA 72-4]

Tumor-associated glycoprotein (TAG-72) is an antigen recognized by monoclonal antibody (MAb) B 72.3 which was generated against a membrane enriched fraction of human mammary carcinoma cells. CA 72-4 is a novel antigen determinant on TAG-72 and is a quantitative radioimmunometric assay system utilizing two MAbs (CC-49, B 72.3) which react with circulating TAG-72 expressed by human carcinomas. We have employed the CA 72-4 RIA system to measure the antigen in sera. The optimum condition for this assay was found to be a 4 hour incubation at 37 degrees C for the first reaction and a 20 hour incubation at 4 degrees C for the second reaction. Under these conditions, intra-assay variation of the control sera was C.V. 3.0-5.2% and inter-assay variation was 5.6-8.3%. The mean +2 SD of CA 72-4 concentration in 468 healthy persons was 3.9 U/ml. Therefore, less than 4.0 U/ml was taken as the cut off level for the CA 72-4 serum assay. The largest population in healthy persons was at the range of 1.5-2.0 U/ml. Only 15 of 468 persons (3.2%) demonstrated serum CA 72-4 levels more than 4.0 U/ml. These data thus indicate the efficacy of CA 72-4 RIA system for the serum assay as a novel tumor marker. The clinical evaluation of CA 72-4 in patients with epithelial malignancies is now underway.

[Levels of circulating tumor-associated glycoprotein (TAG-72) in patients with carcinoma using a novel tumor marker, CA 72-4]

CA72-4 is a novel quantitative immunoradiometric assay system utilizing two monoclonal antibodies CC-49 and B72.3, which recognize a tumor-associated glycoprotein (TAG-72). We have utilized the CA72-4 RIA kit to measure serum levels of TAG-72 in 205 patients with carcinoma and 192 patients without carcinoma. The cut-off value (4.0 U/ml) was obtained according to the levels and the distribution of CA72-4 in 468 healthy individuals. The positive rates in 82 patients with gastric cancer, 55 with colorectal cancer, 24 with pancreatico-choledochal cancer, 36 with breast cancer, and 3 with ovarian cancer were 52%, 55%, 46%, 39%, and 67%, respectively. Fifty percent of the sera from 205 patients with carcinoma demonstrated increased levels of CA72-4, whereas only 10% of the sera from 192 patients without evidence of malignancy showed levels more than 4.0 U/ml. The average level of serum CA72-4 in the patients with carcinoma was 38.6 U/ml, much higher than that (2.7 U/ml) in patients without malignancy. The patients with gastrointestinal cancer at advanced stages or at recurrence showed higher levels of serum CA72-4 than the patients with cancer at early stages. These results thus indicate that CA72-4 is clinically useful as a novel tumor marker, especially for monitoring serum levels of TAG-72 in patients with gastrointestinal cancer, breast cancer, ovarian cancer and other epithelial malignancies.

Effect of 7-methylated bile acids and bile alcohols on cholesterol metabolism in hamsters

The effect of 7-methyl substituted bile acid and bile alcohol analogues on cholesterol metabolism was studied in the hamster. Animals were fed chow plus 0.1% cholesterol supplemented with 0.1% of one of the following steroids: chenodeoxycholic acid, 7-methyl-chenodeoxycholic acid, 7 beta-methyl-24-nor-5 beta-cholestane-3 alpha, 7 alpha, 25-triol, cholic acid, 7-methyl-cholic acid, or 7 beta-methyl-24-nor-5 beta-cholestane-3 alpha, 7 alpha, 12 alpha,25-tetrol. Cholesterol absorption was determined from fecal analysis after feeding of radiolabeled cholesterol and beta-sitosterol. Of the six compounds studied, chenodeoxycholic acid and 7-methyl-chenodeoxycholic acid decreased intestinal cholesterol absorption (17% and 31% decrease, respectively). Only 7-methyl-chenodeoxycholic acid decreased serum cholesterol concentration (29% decrease), but there were no analogous changes of liver and biliary cholesterol concentration and cholesterol saturation of bile. Total fecal neutral sterol excretion was increased in the groups fed chenodeoxycholic acid and 7-methyl-chenodeoxycholic acid. In addition, the production of coprostanol was increased in both groups. These data suggest that 7-methyl-chenodeoxycholic acid resembles chenodeoxycholic acid in its effect on cholesterol metabolism and may be a potential candidate for further studies of its gallstone-dissolving properties.

Bile salts of the West Indian manatee, Trichechus manatus latirostris: novel bile alcohol sulfates and absence of bile acids

The bile salts present in gallbladder bile of the West Indian manatee, Trichechus manatus latirostris, an herbivorous marine mammal of the tropical and subtropical margins of the Atlantic Ocean, were found to consist of a mixture of bile alcohol sulfates. Bile acids, previously believed to be present in all mammals, were not detected. Using chromatography, mass spectrometry, and 1H- and 13C-nuclear magnetic resonance spectroscopy, the major bile alcohol was identified as 5 beta-cholestane-3 alpha,6 beta,7 alpha-25,26-pentol; that is, it had the nuclear structure of alpha-muricholic acid and the side chain structure of bufol. This compound has not been described previously and the trivial name "alpha-trichechol" is proposed. The second most abundant compound was 5 beta-cholestane-3 alpha,7 alpha,25,26-tetrol. Other bile alcohols were tentatively identified as 5 beta-cholestane-3 alpha,6 beta,7 beta,25,26-pentol (named beta-trichechol), 3 alpha,6 alpha,7 beta, 25-26-pentol (named omega-trichechol) and 5 beta-cholestane-3 alpha,6 beta,7 alpha,26-tetrol. The 1H and 13C NMR spectra of the four 6,7 epimers of 3,6,7 trihydroxy bile acids are described and discussed. All bile alcohols were present as ester sulfates, the sulfate group being tentatively assigned to the 26-hydroxy group. 12-Hydroxy compounds were not detected. The manatee is the first mammal found to lack bile acids, presumably because it lacks the enzymes required for oxidation of the 26-hydroxy group to a carboxylic acid. Trichechols, like other bile salts, are water-soluble end products of cholesterol metabolism; whether they also function as biological surfactants in promoting biliary cholesterol secretion or lipid digestion is unknown.

Mobile unit for use in mass screening for breast cancer

Since 1977, mass screening for breast cancer has been carried out in Miyagi prefecture, Japan. The main activities involve itinerant screening in the communities and group screening at the workplaces. The first step in this screening is the physical examination; the second step, for women with suspicious findings, is examination by mammography and ultrasonography, in a specially equipped mobile unit. The number of subjects screened over a seven-year period ending in March, 1984, was 94,953. Mammography was performed on 4,485 subjects (4.7 per cent) Breast cancer was detected in 116 subjects (0.12 per cent). Since 1980, 2,292 high risk subjects have undergone mammography as the first step screening. The detection rate (0.35 per cent) for this group was higher than for the general subjects examined. Therefore, mammography performed in a mobile unit is a suitable approach for the detecting and diagnosing of breast cancer.

Identification of new bile alcohols, 5 beta-cholestane-3 alpha,7 alpha,24,26-tetrol, 5 beta-cholestane-3 alpha,7 alpha,25,26-tetrol, and 5 beta-cholestane-3 alpha,7 alpha,26,27-tetrol in human gallbladder bile

The nature of cholestanetetrols present as the glucurono-conjugates in human gallbladder bile was studied. Glucurono-conjugated bile alcohols were isolated by ion exchange chromatography and, after enzymatic hydrolysis, were fractionated by reversed phase partition chromatography to give a fraction containing tetrahydroxy bile alcohols which was analyzed by gas-liquid chromatography and mass spectrometry. Along with the three previously identified bile alcohols, 5 alpha- and 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha,24-tetrols, and 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha,26-tetrol, three new cholestanetetrols, possessing two hydroxyl groups in the ring system and two in the side chain, were detected in the tetrahydroxy bile alcohol fraction. These new bile alcohols were identified as 5 beta-cholestane-3 alpha, 7 alpha,24,26-tetrol, 5 beta-cholestane-3 alpha, 7 alpha,25,26-tetrol, and 5 beta-cholestane-3 alpha, 7 alpha,26,27-tetrol by direct comparison of their gas-liquid chromatographic behaviors and mass spectral data with those of authentic standards prepared from chenodeoxycholic acid by partial synthesis.

Identification of unconjugated bile acids in human bile

Unconjugated bile acids in the bile of healthy and diseased humans were determined qualitatively and quantitatively by means of gas-liquid chromatography and gas-liquid chromatography-mass spectrometry, after their isolation by ion-exchange chromatography. In a healthy person and three patients with cholelithiasis, unconjugated bile acids comprised 0.1-0.4% of total biliary bile acids. The bile acid composition of the unconjugated fraction was quite different from that of the glycine- or taurine-conjugate fraction, in that it contained a relatively large proportion of unusual bile acids including C23 and C27 bile acids. In two patients with cerebrotendinous xanthomatosis, C22 and C23 bile acids were the major constituents of the biliary unconjugated bile acids, and comprised about 0.8% of total bile acids; no detectable amounts of C27 bile acids were found in their bile. The analysis of biliary unconjugated bile acids may be useful for the diagnosis of metabolic diseases concerning bile acids, particularly the accumulation or disappearance of unusual bile acids.

Skull metastasis of thyroid carcinoma. Study of 12 cases

Over the past 33 years the authors have treated 12 cases of skull metastasis from thyroid carcinoma, accounting for 2.5% of a total of 473 cases of thyroid cancer. A study of these 12 cases revealed the following characteristics. The mean age of the patients was 60.4 years and the predominant incidence was in the seventh decade of life. The incidence of skull metastasis from thyroid cancer was higher among women than among men. The primary sign was a soft hemispheric tumor resting on the skull. The tumors were rich in vascularity with osteolytic changes in the skull. The average period from diagnosis of the thyroid tumor until thyroidectomy was 14.3 years, and until discovery of the skull metastasis was 23.3 years. The clinical course was thus very long. The most frequent histopathological presentation was follicular adenocarcinoma. Such lesions were morphologically well differentiated, with little pleomorphism and atypism, but detailed examination showed infiltration into the vascular lumen or capsule. The mean survival time in these patients was 4.5 years from the time of diagnosis. The prognosis in this lesion was relatively poor, considering its long clinical course.

Trial of early detection of breast cancer by mass screening

Since 1977, mass screening for breast cancer has been conducted in Miyagi Prefecture, Japan. The main activities consist of itinerant screening in the communities and group screening at the workplace. In addition, examinations were also carried out at a detection center. The total number of subjects examined was 90,076 in mass screening, with 4172 (4.6%) of them requiring a second examination. The overall breast cancer detection rate was 0.12% in the mass screening. In contrast, it was 3.1% at the center examination. Cytologic studies of nipple discharge were performed on 31,833 subjects. Positive findings were seen in 4 (0.004%). The incidence of smaller tumors was higher and that of nodal metastasis was lower in subsequent examinations than in the initial screening. In the high-risk group, who also underwent mammography at first screening, the detection rate was higher than that among general subjects examined.

[Trial of early detection of breast cancer by mass screening in Miyagi Prefecture]

Mass screening for breast cancer which was commenced by Miyagi Cancer Society in 1977 has been carried out on 94953 examinees. The main activities comprise itinerant screening in the communities and group screening at the workplaces. In addition to two types of mass screening, examination was also performed at the detection center. The overall breast cancer detection rate was 0.12% in mass screening. In contrast it was 3.1% at the center. Early breast cancer, however, was more frequently found in mass screening than at the center examination. The cytologic studies of nipple discharge were performed on 14314 subjects as first screening. Positive finding was seen in 5 (0.005%). In high risk group, which also underwent mammography at first screening, the detection rate was higher than that among general examinees. Method for effective procedures for detecting early breast cancer are now under study.

Follicular reconstruction and hormone production by human adenomatous goiter cells in culture

Morphological and functional properties of dispersed cells of human adenomatous goiter and those of the thyroid tissue adjacent to and distant from the nodular lesion (normal control) were investigated. In the presence of TSH, reconstructive arrangement of adenomatous goiter cells into a three-dimensional follicular structure occurred in a similar manner to that of normal controls. An addition of thyrotropin (TSH) to culture resulted in the secretion of thyroid hormones in control cells, but adenomatous goiter cells showed no response to TSH. It was found that the ratio of rT3, T3, the ratio of an inactive to an active form, was about three times higher in adenomatous goiter than in normal control. These findings suggested that conversion from T4 to rT3 is increased in adenomatous goiter.