Vimentin-positive squamous cell carcinoma arising in a burn scar. A highly malignant neoplasm composed of acantholytic round keratinocytes

Two patients had unusual squamous cell carcinoma (SCC) arising in a burn scar. The SCCs rapidly recurred and metastasized after radical operation, and the patients died of disseminated metastases. Histopathologically, the SCC was poorly differentiated and consisted of acantholytic round cells that diffusely proliferated into the deep dermis. However, small, solid nests composed of squamoid cells were focally observed. Immunohistochemical studies revealed that the acantholytic round neoplastic cells expressed not only keratin but also vimentin, and the coexpression was substantiated with double immunostaining. Vimentin-positive SCC composed of acantholytic round neoplastic cells may be a highly malignant subset of cutaneous SCC.

[Fulminant autoimmune hemolytic anemia with multiple organ failure]

We report a rare case of fulminant autoimmune hemolytic anemia (AIHA) with multiple organ failure (MOF). A 40-year-old man was emergently admitted to our hospital because of conscious disturbance and jaundice. The peripheral blood revealed RBC 68 x 10(4)/microliter, Hb 3.5 g/dl, Ht 8.9%, Ret 30% (20,400/microliter), WBC 20,300/microliter, Plts 16.9 x 10(4)/microliter, indirect bilirubin 9.4 mg/dl. Both direct and indirect Coombs test were positive and the IgG autoantibody was identified. Bone marrow aspiration revealed hypercellularity with increased megakaryocytes and erythroid hyperplasia. The patient was diagnosed as having idiopathic warm type of AIHA and the therapy was started with prednisolone 80 mg/day from the first day of admission but hemolysis with reticulocytopenia was so rapidly progressive that he was in acutely life-threatening state and MOF (acute renal failure, adult respiratory distress syndrome, congestive heart failure, liver dysfunction, rhabdomyolysis) appeared on the third hospital day. Plasma exchange therapy and hemodialysis were started and high dose methylprednisolone was given soon after rapid administration of sufficient blood transfusion. Dramatic improvement of hemolysis was noted and MOF was controlled after starting these therapies, but he died of exacerbation of MOF probably due to sepsis 40 days later.

[Neutrophil dysfunction in chronic neutrophilic leukemia without rearrangements of bcr and immunoglobulin heavy chain genes]

A 67-year-old man was admitted to our hospital with abdominal distension due to hepatosplenomegaly. The peripheral blood revealed Hb content 6.5 g/dl, platelet count 4.7 x 10(4)/microliter, and WBC count 105.8 x 10(3)/microliter with 88% of mature neutrophils. The neutrophil alkaline phosphatase score was 421. Bone marrow aspiration revealed hypercellularity with increased megakaryocytes and myeloid hyperplasia. 46, XY, del 20(q 11) without Philadelphia chromosome was identified by cytogenetic study. The patient was diagnosed as having chronic neutrophilic leukemia and was successfully treated with busulfan, but he died of atypical mycobacteriosis about 20 months later. Analysis of neutrophil function demonstrated diminution of deformability, random mobility, and chemotaxis, but almost normal phagocytosis and bactericidal capacity. Southern analysis showed no rearrangements of breakpoint cluster region (bcr) gene and immunoglobulin heavy chain gene.

Micronucleus induction in mouse bone marrow by phenacetin administered intraperitoneally or orally

The extent and time course of induction of micronucleated polychromatic erythrocytes (MNPCEs) in mouse bone marrow were examined after administration of phenacetin as an insoluble suspension in olive oil by intraperitoneal injection (i.p.) or gastric intubation (p.o.) to 2 strains of mice, MS/Ae and CD-1, at doses up to 1200 mg/kg. The toxicity of phenacetin and the sensitivity of micronucleus induction differed in the 2 strains, but there was little difference in the extent of MNPCEs induced by the 2 administration routes.

Long-term follow-up of hepatitis using computed tomography

Computed tomography of the liver was performed on two patients with subacute hepatitis. The CT findings included the presence of multiple regenerative nodules in the atrophied liver, shown by decreased CT attenuation. Complications due to hepatitis, such as massive ascites and splenomegaly, were also observed. The CT observations during the course of the disease suggested that the hepatic necrosis had been repaired by hypertrophy of regenerating nodules, not by an increase in the number of nodules, which ultimately gave rise to postnecrotic cirrhosis. Scintigraphy confirmed atrophy and repair of the liver. Thus, CT and scintigraphy were considered to be useful for the diagnosis of extensive hepatic necrosis and for evaluating the process of liver repair.

[Clinical trial of T-3262 (Tosufloxacin tosilate) on Salmonella enteritis, and fecal drug concentration and change in the fecal microflora in the acute diarrheal patients. Japan Research Committee of T-3262, Research Group for Acute Infectious Enteritis]

For the purpose of evaluation of clinical efficacy, safety and usefulness on Salmonella enteritis, T-3262 (Tosufloxacin tosilate), a newly developed pyridone-carboxylic acid derivative, was administered to a total of 103 patients and carriers. In addition, in vitro antibacterial activity of T-3262 was determined against the clinical isolates, and compared with those of nalidixic acid (NA), pipemidic acid (PPA), enoxacin (ENX), norfloxacin (NFLX) and ofloxacin (OFLX). And when T-3262 was administered to the patients of acute infectious enteritis, fecal drug concentration and their correlation to the changes in the fecal microflora were investigated. The daily dose of 450 mg T-3262 was administered orally three times after meal for 7 days. A total of 63 cases were evaluated (one case of mixed infection caused by Shigella flexneri and Salmonella sp. was included). The clinical efficacy was good in all the enteritis (N = 6). As the bacteriological effect, 60 out of 61 were eradicated, and eradication rate was 98.4%. Adverse effects were observed in four of 102 cases (3.9%), consisting of one with skin rash, one with nausea, headache and stomatitis and two with soft stools. Deteriorations in laboratory findings were seen in 5 of 23 cases (17.4%), consisting of one with elevated GOT, two with elevated GOT and GPT, one with elevated BUN and one with increased eosinophiles count, although they were all slight in degree. MICs of T-3262 which inhibited 90% of the isolates of Salmonella spp. was 0.05 microgram/ml, which was the lowest among the quinolone derivatives tested. The values of the fecal drug concentration of 7 cases of acute infectious enteritis, to which T-3262 administered, were higher than that of MIC90 and recovery rates of T-3262 were distributed from 2.85 to 46.3%. The degrees of changes of the drug concentrations were dependent on individual cases, and did not show the same trend. In addition, changes in the fecal microflora with in 24 hrs after T-3262 administration did not show the same trend.

Pathology of anomalous junction of the pancreaticobiliary ductal system: mutagenicity of the contents of the biliary tract and nuclear atypia of the biliary epithelium

Congenital biliary dilatation is frequently complicated by biliary tract cancer, and anomalous junction of the pancreaticobiliary ductal system, a major factor constituting the pathology of this disease, is considered to be important as a background for carcinogenesis in the biliary tract. To clarify the mechanism of carcinogenesis in the biliary tract under the circumstance of anomalous junction, we evaluated the mutagenicity of the contents of the biliary tract in patients with congenital biliary dilatation and analyzed the nuclear atypia of the biliary epithelium by fluorocytometry. A mutagenicity test using Bacillus subtilis showed positive results in 6 of 12 patients. Since mutagenicity correlates well with carcinogenicity, these results suggest the necessity of separation surgery between the bile and pancreatic ducts in patients with anomalous junction regardless of the presence or absence of biliary dilatation. On the other hand, DNA histograms of the nuclei of gallbladder epithelial cells produced by fluorocytometry in 4 patients revealed a high incidence of polyploid DNA in 2 patients with marked hypertrophic changes. These patients were also positive for mutagenicity of the contents of the biliary tract, suggesting that mutagens are involved in the atypia at the cellular and nuclear levels.

[Clinical trial of T-3262 on acute enteritis. Japan Research Committee of T-3262, Research Group for Acute Infectious Enteritis]

For the purpose of evaluation of clinical efficacy, safety and usefulness on acute infectious enteritis (bacillary dysentery, and enteritis caused by Salmonella spp., Campylobacter spp., enteropathogenic E. coli, and so on), T-3262, a newly developed pyridone-carboxylic acid derivative, was administered to a total of 136 patients and carriers. In addition, in vitro antibacterial activity of T-3262 was determined against the clinical isolates, and compared with those of nalidixic acid (NA), pipemidic acid (PPA), enoxacin (ENX), norfloxacin (NFLX) and ofloxacin (OFLX). The daily dose of 450 mg of T-3262 was administered orally three times after meals for 5 days, with the exception of 7 day administration against Salmonella enteritis. A total of 89 cases were evaluated; 23 with Shigella spp., 30 with Salmonella spp., 15 with Campylobacter spp., 6 with enteropathogenic E. coli, and 15 cases with the other pathogens or pathogen-negative. The efficacy on clinical symptoms judging from duration of fever, and duration of diarrhea and abnormal stool character was 100% in all the enteritis except enteropathogenic E. coli enteritis, in which it was 50% (n = 2). Concerning bacteriological response, elimination of the causative organisms from the feces was 100% in Shigella spp. (n = 19), Salmonella spp. (n = 30), and enteropathogenic E. coli (n = 6), although 64.3% in Campylobacter spp. (n = 14). As an adverse effect, epigastric discomfort was observed in one (0.8%) of 130 cases. Deteriorations in laboratory findings were seen in five (6.2%) of 81 cases, consisting of two with elevated GOT and GPT, two with elevated GPT, and one with increased eosinophils count, although they were all slight in degree. MICs of T-3262 which inhibited 90% of the isolates of Shigella spp, Salmonella spp., and Campylobacter spp., were 0.025, 0.05, and 0.78 microgram/ml, respectively. These values were lowest among the quinolone derivatives tested, except that the MIC90 against Campylobacter spp. was the same as that of ofloxacin.

[Comparison of clinical efficacy of lomefloxacin (LFLX, NY-198) and pipemidic acid (PPA) in the treatment of infectious enteritis by a double-blind method. The Japan Research Committee of Lomefloxacin Research Group Enteritis]

The clinical efficacy, safety and usefulness of lomefloxacin (LFLX, NY-198), a new quinolone antimicrobial agent, were compared with those of pipemidic acid (PPA) in the treatment of infectious enteritis (bacillary dysentery, enteropathogenic Escherichia coli enteritis and Campylobacter enteritis) by a double blind method. Daily dosage of LFLX and PPA was 600 mg and 2000 mg, respectively administered orally divided into 4 doses. The duration of the treatment was 5 days. Of 290 cases studied, 100 cases were excluded and 21 cases were dropped from analysis of effectiveness and usefulness. The effectiveness and usefulness was evaluated in 169 cases (LFLX group: 83, PPA group: 86). There was no significance difference between the two groups in any background characteristics. The results obtained were as follows: 1. In 73 symptomatic patients (LFLX group: 35, PPA group: 38) on the day of the beginning of administration, the clinical effect was 91.4% in the LFLX group and 84.2% in the PPA group with no significant difference between the two groups. 2. In a total of 184 strains (LFLX group: 90, PPA group: 94), the bacteriological effects of LFLX (93.3%) was superior to that of PPA (80.9%) with significant difference (p = 0.0153). 3. In 169 evaluable patients, the global clinical effects of LFLX (92.8%) was superior to that of PPA (79.1%) with a significant difference (P = 0.0144). 4. Side effects were observed in 1 (0.7%) of the 141 patients in the LFLX group and none of the 143 patients in the PPA group. Abnormal laboratory test values were noted in 10 (7.6%) of the 132 patients treated with FLLX and 7 (5.1%) of the 136 patients treated with PPA, but they as no significant difference between the two groups. 5. In 169 evaluable patients, the clinical usefulness of LFLX (91.6%) was superior to that of PPA (76.7%) with a significant difference (P = 0.0111). From these results, LFLX is considered to be a clinically useful medicine in the treatment of infectious enteritis including bacillary dysentery.

Dioxins in cigarette smoke

Dioxins in cigarettes, smoke, and ash were determined using gas chromatography/mass spectrometry. The total concentration of polychlorinated dibenzo-p-dioxins (PCDDs) in cigarette smoke was approximately 5.0 micrograms/m3 at the maximum level, whereas various congeners from tetra-octa-chlorodibenzo-p-dioxin (-CDD) were detected. Particullary, the total concentration of hepta-CDD congeners was the highest among these congeners. Mass fragmentograms of various PCDD congeners were similar to those in flue gas samples collected from a municipal waste incinerator. The PCDD congeners that were not present in the cigarettes were found in the smoke samples. The 2,3,7,8-TCDD toxic equivalent value--an index for effects on humans--for total PCDDs in smoke was 1.81 ng/m3 using the toxic factor of the United States Environment Protection Agency. Daily intake of PCDDs by smoking 20 cigarettes was estimated to be approximately 4.3 pg.kg body weight/day. This value was close to that of the ADIs: 1-5 pg.kg body weight/day reported in several countries. A heretofore unrecognized health risk was represented by the presence of PCDDs in cigarette smoke.

Accumulation and declination of chlordane congeners in mice

A metabolic experiment involving technical chlordane in mice was carried out in vivo by single and repeated oral administration. In the single oral dose group, residues of trans- and cis-chlordane in mouse whole body showed a maximum content at 5 hours after administration; thereafter, the body content decreased rapidly. For other congeners, the residues of trans- and cis-nonachlor reached a maximum at 10 hours, the residual levels forming a plateau. The intermediate metabolite oxychlordane was detected 1 hour after the administration of technical chlordane, the content in the mouse body increasing with time. In the repeated oral dose group, although technical chlordane was administered repeatedly, increases in trans- and cis-chlordane content were not observed for 29 days. On the other hand, the nonachlor and oxychlordane content increased gradually throughout the observation period. These findings suggest that the accumulation of nonachlors and oxychlordane in the animal body must be high and sufficient attention must be paid to their toxic effect.

[Studies on determination of minimum bactericidal concentrations of penicillin-G for beta-hemolytic streptococci]

Minimum bactericidal concentrations (MBC) of penicillin-G were determined for 94 isolates of beta-hemolytic streptococci: 37 group A; 40 group B; 6 group C; and 11 group G. Our experiments focused on the influence of technical variable factors on the outcome of the MBC test such as inoculum preparation, manner of inoculation, technique of sampling for survivors, growth phase of inoculum, final concentration of inoculum, and time of incubation. The results were summarized as follows: 1. The mean MBC, ranged from 0.0145 microgram/ml (group A) to 0.084 microgram/ml (group B). The MBC/MIC ratio ranged from 1- to 4-fold (3 strains: 2 group A, 1 group C), showing no penicillin-G tolerance. 2. Logarithmic-phase inocula used were prepared by incubating 10 ml Mueller-Hinton broth (MHB) in water bath at 37 degrees C for 4 to 5 h after adding 0.01 ml of 24 h-incubated cultures. 3. 0.1 ml of logarithmic-phase inocula were released on the surface of penicillin-containing MHB (1 ml) without shaking or splashing. 4. It was important to resuspend the organisms by vortexing 4 h before tubes were sampled so that any organisms contaminating glassware above the meniscus were exposed to antibiotic. 5. No carry-over effect was observed with 0.01 ml samples. 6. Effect of bacterial growth phase on outcome of MBC test was not confirmed. 7. All tests used final volumes of 1.1 ml of MHB containing 10(5) cells/ml and 24-h incubation time.

[A clinical study of a multiregression analysis on the NK activity and related clinical factors in patients with lung cancer]

Using 24 lung cancer patients (20 males and 4 females) who had received radiotherapy, a multivariate analysis has been performed in relation to 19 factors suspected of exerting an effect on natural killer (NK) cell activity. As influencing factors, two factors of the disease, the stage (p less than 0.05) and the leukocyte count (p less than 0.08), were calculated to be significant. In the univariate analysis, the NK activity was found to be significantly low (p less than 0.05) when the leukocyte count was 7,000 or higher. In addition, patients who had died during the course of radiotherapy showed an NK activity which was significantly lower (p less than 0.05) than the activity manifested in both the disease-free patients and the relapsed progressive disease patients. Moreover, the patients with a PS of 40% or less had a significantly lower NK activity than the patients with a PS of 50% or more, though no correlation was found between the NK activity and the disease stage. In the use of this radiotherapy, the NK activity was found to be more strongly influenced by the size of the irradiated field than by the irradiated dose.

Metabolism of tritiated water in the cell nucleus and intracellular substances of the rat

Tritiated water was given to rats in single oral doses, and the cell fractions for each organ were prepared by ultracentrifugation for measurement of the concentration of tissue-bound tritium. The concentration of tissue-bound tritium reached a peak relatively soon after intubation, 1-4 days after administration. The initial concentration of tissue-bound tritium in liver and kidney was high in the mitochondrial and microsomal fractions but low in the nuclear and cytosol fractions. The initial tissue-bound tritium concentration in the brain was high in the mitochondrial and microsomal fractions but low in the nuclear and cytosol fractions. The initial concentration of tissue-bound tritium in the testes was high in the mitochondrial, microsomal, and cytosol fractions but low in the nuclear fraction. The half-life for the long component was larger in the nuclear, mitochondrial, and microsomal fractions of the brain than in the other organs according to an interorgan comparison of each fraction. As for the testes, the values for the mitochondrial and microsomal fractions were larger than those for the other organs.

[A case of aortitis syndrome which presented coarctation of aorta due to intraluminal flap formation in the middle of the thoracic aorta]

We present a rare case of aortitis syndrome associated with dilatation of aorta and coarctation-like effect due to the intraluminal flap formation originated from dissected wall of the aorta. A 31-year-old woman was admitted to our hospital complaining of shortness of breath, palpitation and cough. On admission, her physical status showed congestive heart failure and hypertension of upper extremities and hypotension of lower extremities. Bruits were audible over the neck, the anterior chest and the back. Serological studies showed active inflammation. Chest X-ray film showed upper mediastinal widening, cardiomegaly and pulmonary edema. Aortitis syndrome was strongly suggested by these clinical findings, so that prednisolone therapy was started on 3rd hospital day. Special examinations were performed several days later when inflammatory changes showed a tendency to improve. Chest CT scan, RI angiography and MRI studies showed an aneurysmal dilatation from the ascending aorta to the mid-thoracic aorta. Aortography demonstrated a flap at the terminal portion of this aneurysmal dilatation and grade II (Sellars) aortic regurgitation. There was a pressure difference of 80 mmHg between the parts abutting cranial and caudal sides of the flap. A surgical operation was, then, performed to correct the pressure difference. The dissected wall was extruded toward the aortic lumen creating a flap (2 cm in length). This flap was resected and an artificial graft was inserted. Histologically, the flap consisted of adventitia, media and intima.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary structure of a ribonuclease from bovine brain

The primary structure of a pyrimidine base-specific ribonuclease from bovine brain was determined. The sequence determined is (sequence; see text). Although the sequence homology of this RNase with bovine pancreatic RNase A is 78.2%, it consists of 140 amino acid residues, and it is 16 amino acid residues longer than RNase A at the carboxyl-terminal. In addition to an N-glycosylated long carbohydrate chain, the bovine brain RNase has two short O-glycosylated carbohydrate chains at the 129th and the 133rd serine residues. The additional C-terminal tail of the bovine brain RNase has a unique composition: 6 proline, 5 hydrophobic amino acids, and two basic amino acids, arginine and histidine.

Primary structure of a non-secretory ribonuclease from bovine kidney

The primary structure of a non-secretory ribonuclease from bovine kidney (RNase K2) was determined. The sequence determined was VPKGLTKARWFEIQHIQPRLLQCNKAMSGV NNYTQHCKPENTFLHNVFQDVTAVCDMPNIICKNGRHNCHQSPKPVNLTQCNFIAGRYPDC RYHDDAQYKFFIVACDPPQKTDPPYHLVPVHLDKYF. The sequence homology with human non-secretory RNase, bovine pancreatic RNase, and human secretory RNase are 46, 34.6, and 32.3%, respectively. The bovine kidney RNase has two inserted sequences, a tripeptide at the N-terminus and a heptapeptide between the 113th and 114th position of bovine pancreatic RNase; on the other hand, it is deleted of the hexapeptide consisting of the 17th to the 22nd amino acid residue of RNase A. The amino acid residues assumed to be the constituents of the bovine pancreatic RNase active site are all conserved except F120 (L in RNase K2).

Purification of acid ribonucleases from bovine spleen

Two acid RNases were purified from bovine spleen by means of ammonium sulfate fractionation, chromatographies on-phospho-cellulose, heparin-Sepharose CL-6B, poly G-Sepharose, and 2', 5'-ADP-Sepharose, and gel filtration on Toyopearl HW 55F. Both purified preparations were homogeneous as judged by disc electrophoresis at pH 4.3. They were designated as RNase BSP1 and RNase BSP2 in the order of elution from a phospho-cellulose column. RNase BSP2 was immunologically indistinguishable from RNase K2 from bovine kidney. RNase BSP1 was a typical pyrimidine base-specific, uridylic acid-preferential RNase and had very sharp pH optimum at 6.5. RNase BSP1 thus obtained was a glycoprotein giving two major bands on SDS-slap electrophoresis. Although the apparent molecular weight of RNase BSP1 was distributed in the range of 27,000-20,000, it decreased to about 17,000-18,000 after endoglycosidase F digestion. The N-terminal amino acid sequence up to the 20th amino acid had no homology to those of RNase K2 and RNase A.

Effect of gavaged chemical form of 241Am on its retention in mice

The retention of 241Am in mice 48 h after administration by gavage is reported here. The 241Am was given to mice in the form of either 241Am nitrate or 241Am citrate. The 241Am was also injected into rats in the same form. The homogenized livers of those rats were subsequently administered by gavage to another group of mice. The retention of 241Am citrate was 1.5 X 10(-2)% of the original dose and was the highest among the compounds examined. The retention of biologically incorporated 241Am into the liver as 241Am nitrate and as 241Am citrate was 2.4 X 10(-3) and 2.6 X 10(-3)%, respectively, and was similar to the retention of 241Am nitrate, which was 2.8 X 10(-3)%. The ratio of the retention in the carcass to that in the liver for the 241Am citrate was lower than that of the 241Am nitrate and the biologically incorporated 241Am. This difference indicates that the distribution of 241Am in the animal body depends on the chemical form administered. The retention of liver-incorporated 241Am as citrate after autolysis of the liver is similar to that of fresh liver-incorporated 241Am citrate.

Concentration of fallout plutonium in tissues of Japanese who died during 1980-1984

The concentrations of fallout 239 + 240Pu in various body tissues of subjects who were born before 1941 and who died in Akita and Niigata Prefectures in Japan during 1980-1984 are reported. The median concentrations in vertebrae, sternum, liver, lung, spleen, and kidney were 0.21, 0.08, 0.62, 0.11, 0.08, 0.03 pCi/kg wet weight, respectively. The concentration levels in vertebrae were approximately three times higher than in the sternum. No significant correlation between the concentration in the various tissues and age at the time of death was observed. No differences in the concentration levels in liver and lung were observed between the sexes. Correlation between the concentration in liver and that in lung was not significant. The concentration in liver was similar to that estimated from the ICRP 30 model. However, the concentration in lung was considerably higher than the estimated value. This difference may be caused by the pulmonary lymph nodes contained in the present lung samples. To obtain the average concentration of plutonium in the entire skeleton, further information regarding the macrodistribution of plutonium is required.

Geographical distribution of cerebrovascular disease mortality and food intakes in Japan

The present study focuses on an analysis of the relationship between cerebrovascular disease mortality and food intake. For this purpose, standardized mortality ratios(SMRs) from cerebrovascular disease were calculated for 3341 basic administrative units (wards, cities, towns and villages) between 1969 and 1978 in Japan. The major nutrient intakes and 30 selected food items were obtained from the 1974-1974 Ministry of Health and Welfare, National Nutrition Surveys in 1040 randomly sampled census tracts in 600 areas (18% of the nation). Our analysis demonstrates that the geographical pattern of cerebrovascular disease SMRs in Japan vary from higher in East Japan to lower in the West, and higher in the less urbanized areas, and lower in the more urban ones. Foods positively associated with cerebrovascular disease were rice and other starchy foods, pork, algae (seaweed), and salty foods such as miso (soybean paste), pickled vegetables, soy sauce and salted fish. All of these foods, with the exception of pork, are part of the traditional Japanese diet. On the contrary, mortality was negatively associated with intakes of wheat, butter and margarine, beef and eggs, items considered to be representative of a European diet. Using a stepwise multiple regression analysis, miso and salted fish were selected as positive, and beef and eggs as negative correlates of cerebrovascular disease mortality. According to these results, it is suggested that these four foods are useful as negative and positive indicators of improvement in dietary intakes as related to the reduction in the occurrence of cerebrovascular disease.

An examination of 3H and 14C hand contamination at the radioisotope laboratory of a medical school

In a field of bio-medical science, low energy beta-emitting nuclides, such as 3H and 14C, are used frequently. However, contamination with those nuclides on laboratory workers is not detectable by the ordinary hand-foot-cloth monitor, if it occurs. Therefore, a new contamination check method, hand washing combined with lyophilization, was studied and feasibility of the method has been confirmed. The lyophilization step of the method takes about ten hours so it is not practical to use the method as a daily contamination check. However, it can be done at regular intervals and it will give valuable information for the maintenance of the radioisotope laboratory.

The absorption and excretion of butylated hydroxyanisole in beagle dogs

Recent studies have indicated that administration of [14C]butylated hydroxyanisole (BHA) to rats, either orally or by intraperitoneal (i.p.) injection, resulted in high retention of radioactivity in the forestomach. The present study was undertaken to investigate the fate of [14C]BHA in non-rodents. 2 Groups of 5-mth-old male beagle dogs were fed a diet containing either 3% or 0.03% BHA for 7 days, and were injected i.p. with 3-tert-[methyl-14C]butyl-4-hydroxyanisole (Amersham International) at a dose of 30 muCi/kg. On the 7th day after [14C]BHA injection, all dogs were killed after fasting overnight, and the liver, kidney, heart, fat tissue and stomach were collected for radioanalysis. An additional 3 beagles served as control group. The fate of BHA after the single i.p. injection of [14C]BHA was examined by the determination of 14C-radioactivity in whole body, blood, urine, feces and several tissues. Blood, urine and feces samples were collected daily for 7 days. Blood samples were collected at intervals for 24 h. BHA was rapidly taken up in the bloodstream, and 50-80% of the total radioactivity was recovered in the urine within 2 days. 15-30% Appeared in the feces within 2 days. The tissue distribution of radioactivity 7 days after [14C]BHA injection showed only a small portion remaining in the stomach (0.16-0.19% of dose/g), liver (0.3-1.7%) and other tissues (0.02%). The radio-activity was almost evenly distributed in the three parts of the stomach (cardia, corpus and pylorus). These findings are in contrast with the previous data in rats that BHA can accumulate in high concentrations in the forestomach.

Modification of a ribonuclease from Rhizopus sp. with 1-cyclohexyl-3-(2-morpholinyl-(4)-ethyl)carbodiimide p-toluenesulfonate

The carboxyl group in a ribonuclease from Rhizopus sp. (RNase Rh) was modified by a water-soluble carbodiimide, 1-cyclohexyl-3-(2-morpholinyl-(4)-ethyl)carbodiimide p-toluenesulfonate (CMC). From the relation between the extent of modification and the enzymatic activity, it was concluded that at least the modification of two carboxyl groups seemed to induce the loss in enzymatic activity. In the presence of 1 M cytidine, RNase Rh activity was protected from the CMC-modification. Under conditions in which the enzyme was inactivated to 20% activity, about 70% of the enzymatic activity was retained in the presence of cytidine. The inactivation of the RNase Rh pre-treated with CMC in the presence of cytidine with [14C]CMC indicated that the RNase Rh lost its enzymatic activity with the incorporation of about one [14C]CMC. Therefore, it could be concluded that one carboxyl group is involved in the active site of RNase Rh. The binding of the CMC-modified RNase Rh with 2'-AMP was studied spectrophotometrically. The affinity of the modified RNase Rh towards 2'-AMP decreased markedly upon CMC modification.

Purification and properties of bovine kidney ribonucleases

Two RNases (RNases K1 and K2) were purified from bovine kidney by means of column chromatography on phospho-cellulose, Sephadex G-50, CM-cellulose, heparin-Sepharose, nd agarose-APUP. They were named RNase K1 and RNase K2 in order of elution from the heparin-Sepharose column. The purity of RNase K1 thus obtained was about 90% by SDS-disc electrophoresis. RNase K2 was purified to homogeneity by SDS- and pH 4.3 disc electrophoresis. The yield of RNase K2 was 3.4 mg from 11 kg of kidneys. The antigenic properties of the two bovine renal RNases were studied by Ouchterlony's double diffusion analysis. RNase K1 and RNase A were serologically indistinguishable. RNase K2 did not cross-react immunologically with RNase K1 or RNase A. The molecular weights of these RNases determined by gel-filtration on Sephadex G-50 were 13,400 and 14,600 for RNase K1 and RNase K2, respectively. The pH optima for RNase K1 and RNase K2 were 8.5 and 6.5, respectively. Both RNase K1 and RNase K2 were as acid stable as RNase A. RNase K2 was less heat-stable than RNase K1 and RNase A. Although both renal RNases were pyrimidine nucleotide-specific enzymes, RNase K1 and RNase A were more preferential or cytidylic acid than RNase K2. The chemical composition of RNase K2 was determined. RNase K2, like human urinary RNase Us, contained one tryptophan residue. The N-terminal sequences of RNase K2 and RNase Us were determined by Edman degradation. Rnase K2 had a homologous sequence of about 10 amino acid residues with the sequence of RNase Us, a typical non-secretory RNase, within the N-terminal 30 residues.

Bacterial reversion assay and micronucleus test carried out on hydrogenated glucose syrups 'Malti-Towa' (powder) and maltitol crystal

Two preparations of maltitol (4-O-alpha-D-glucopyranosyl-D-sorbitol), hydrogenated glucose syrups and maltitol crystal, were examined for genotoxic potential by a battery of short-term tests. In the bacterial reversion assay, maltitol induced no detectable revertants in any of the tester strains, Salmonella typhimurium TA98, TA100, TA1535, TA1537, TA1538, or Escherichia coli WP2/pKM101 at doses of 0.5-50 mg per plate with and without rat liver S9 mix. In the micronucleus test, no significant increase in the frequency of micronucleated erythrocytes was observed in bone marrow of mice after administration of the two preparations at 3.75-30 g per kg by gastric intubation.