Isolation and preliminary characterization of ACNU-resistant sublines of rat brain tumors in vivo.

Two variant cells lines resistant to the nitrosourea derivative ACNU ((1-4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride), namely C6/ACNU and 9L/ACNU, were selected in vivo from rat brain tumors. Stable resistance to ACNU proved to be a characteristic of these cell lines, whether they were grown in vivo or in vitro. These cell lines exhibited a different pattern of cross-resistance to a wide range of chemotherapeutic agents with dissimilar chemical structures and mechanisms of action as compared with that of other ACNU-resistant cell lines established in vitro. Distinct cross-resistance was observed in both the C6/ACNU and 9L/ACNU cell lines to chloroethyl-nitrosoureas such as BCNU (carmustine), CCNU (lomustine), and methyl CCNU and, additionally, to vincristine, vinblastine, Adriamycin (doxorubicin), and arabinosylcytosine, but not to bleomycin, methotrexate, cis-platinum, and 5-fluorouracil. This might point to a multifactorial mechanism of drug resistance in ACNU-resistant cell lines derived from rat C6 and 9L brain tumor cells.     

Effect of smoking on fibronectin production by human amnion and placenta.

Fibronectin production from amnion and placental tissues was evaluated in pregnant woman smokers and nonsmokers in order to examine if there were alterations of fibronectin metabolism in intrauterine tissues. In both amnion and placental tissues, cycloheximide inhibited the fibronectin output indicating that it was being synthesized. Mean fibronectin output by amnion in pregnant woman smokers was significantly lower than that in pregnant woman nonsmokers. In contrast, in the placenta from pregnant woman smokers, the output was significantly higher than that in pregnant woman nonsmokers. The present observations indicate that smoking alters an important biochemical constituent in amnion and placenta, possible leading to some complications.     

Myocardial perfusion and clearance of 99mTc teboroxime assessed by SPECT]

99mTc teboroxime is a new myocardial imaging agent that has characteristics of high accumulation in the heart and rapid clearance. We performed tomographic teboroxime study and compared the findings with that of 201Tl. Myocardial teboroxime clearance was calculated by dynamic single photon emission computed tomography (SPECT) using continuous repetitive rotation acquisition method. Teboroxime SPECT image was reconstructed by the three-minute data started from 4 minutes after injection. In 45 myocardial regions (15 patients), complete agreement between 201Tl and 99mTc teboroxime was obtained in 33 regions (73%), when the findings were classified as normal, ischemia and infarction. Significant delay in clearance was seen in the region of coronary stenosis (greater than or equal to 75%) compared with that in the control region (p = 0.0087 at rest, and p = 0.0385 at peak exercise by paired T test). Septum-to-lateral ratios of the clearance and myocardial initial count showed positive correlation (r = 0.743). Further clinical application of this radiopharmaceutical is expected as a new myocardial imaging agent.     

A case-control study of breast cancer among Japanese women: with special reference to family history and reproductive and dietary factors

Summary To study the effects of family history and reproductive, anthropometric, and dietary factors on the risk of breast cancer among low risk populations, we conducted a hospital-based case-control study involving 908 patients with breast cancer and their matched controls, in Japan. A positive family history of breast cancer significantly increased the risk of breast cancer (odds ratio = 1.52, 95% confidence interval: 1.14–2.03). The risk further increased with increasing number of family members affected. Obesity, single marital status, fewer births, a late childbirth, and less consumption of green-yellow vegetables and dairy products were also associated with an increased risk of breast cancer. These associations were independent in multivariate analyses. There was no increase in risk associated with consumption of high fat foods. When analyzed by menopausal status, the association with family history of breast cancer, especially in the first degree of relatives, was more evident for premenopausal breast cancer. The associations with obesity and lower consumption of dairy products were more pronounced for postmenopausal breast cancer, while those with lower parity and single marital status were stronger for premenopausal breast cancer.     

Reevaluation of optimum extraction condition for urinary organic acids using a stable isotope dilution technique]

We reevaluated the optimum conditions for analysis of 13 urinary organic acids using solvent extraction and GC/MS by the stable isotope dilution technique. The acids analyzed were uracil, and lactic, oxalic, 3-hydroxybutyric, succinic, fumaric, glutaric, adipic, pyroglutamic, 2-ketoglutaric, orotic, sebacic, and citric acids. Analytical recovery and accuracy for 13 organic acids ranged from 90 to 107% and from 1.6 to 13.7%, respectively. The optimal pH for most organic acids was 1-2, while that for oxalic and citric acids was 0.25, and that for 2-ketoglutaric and orotic acids was 0.5. The presence of urinary albumin decreased the extraction rates of organic acids, especially of orotic and citric acids; in slight albuminuria (0.5 g/l) the extraction recovery (the extraction rate with albumin/that without albumin) of orotic and citric acid was 38% and 67%, respectively, and in more marked albuminuria (5 g/l), 6% and 26%. Membrane pretreatment with Centricon-3 improved these extraction rates under the condition of albuminuria. Dehydration with the desiccant agent decreased urinary acid extraction rates, especially of uracil and orotic and citric acids. The extraction rates of these three organic acids was decreased in albuminuria and by the desiccant agent. Accurate quantitative analysis of urinary organic acids by the stable isotope dilution technique is necessary for routine examination conducted in clinical laboratories.     

Localization of proteins immunologically related to erythrocyte protein 4.1, spectrin and ankyrin in thyroid gland.

Analogues of erythrocyte protein 4.1, spectrin and ankyrin were examined in the thyroid gland of pig and rat by immunohistochemical techniques. Analysis with immunofluorescence microscopy revealed that the peripheral cytoplasm and apical-lateral plasma membrane of follicle epithelial cells of thyroid glands were stained with antibodies against erythrocyte protein 4.1, spectrin, or ankyrin. The results indicate that membrane skeletal protein lattice might exist in thyroid follicle epithelial cells.     

A case of traumatic spinal subarachnoid hematoma causing compression of the cauda equina]

A case of traumatic spinal subarachnoid hematoma causing compression of the cauda equina is reported here. The patient, a 76 year-old woman, who had fallen down by accident 1 month before, was admitted to our hospital presenting lumbar pain radiating into her right thigh, monoplegia of the right leg and urinary incontinence. Myelography and metrizamide CT demonstrated a filling defect mimicking intradural extramedullary tumor at the level of L1 and L2. Magnetic resonance imagings (MRI) revealed a subacute or chronic hematoma compressing the conus medullaris and the cauda equina. Operation was performed and an old hematoma, which occupied most of the spinal subarachnoid space and compressed the conus and cauda equina from right to left, was removed. No definite bleeding point was detected and no traumatic change was seen on the cord. Neither tumor nor abnormal vessel was detected. After surgery, the symptoms improved partially. On a review of the literature, we found only 4 cases of traumatic spinal subarachnoid hematoma, all of which occupied the cervical or thoracic portion of the spine. Our case is the first report, except for the cases following lumbar spinal tap, of traumatic spinal subarachnoid hematoma causing compression of the cauda equina. Though usually blood in CSF diffuses immediately, a clot may be formed when a large amount of bleeding obstructs the spinal canal. In our case, furthermore, deformity and narrowing of the spinal canal had preceded for many years, following lumbar vertebral compressed fracture related with osteoporosis. This might have promoted the process of canal obstruction and clot formation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acute renal failure with lactic acidosis

This study examined the acid base disturbances in 18 adults with acute renal failure (ARF) from one of new aspects, which is lactate metabolism and pathophysiology. 10 patients (55%) of them were accompanied by lactic acidosis and 9 patients (90%) of those with lactic acidosis also had severe hepatic failure. Mortality of patients with lactic acidosis was 80%, and much higher than that of ARF (66.7%). Lactate, pyruvate, lactate-to-pyruvate ratio (L/P) were 76.7 +/- 15.66 mg/dl, 3.30 +/- 0.74 mg/dl and 19.9 +/- 1.41, respectively. All of them significantly raised, compared to values of healthy adults, patients with liver cirrhosis, chronic renal failure and diabetes mellitus. Arterial pH and HCO3- levels were 7.20 +/- 0.04 and 10.6 +/- 1.20 mEq/l. Anion gap (AG) was 30.0 +/- 3.66 mEq/l. Significant correlations of lactate with pH, HCO3-, AG and L/P were demonstrated, while correlations of lactate with BUN, CR and prothrombin time were not significantly observed. Lactic acidosis results from two mechanisms. One is lactate overproduction (e.g tissue hypoxia) and the other is lactate underutilization (e.g severe liver and/or renal failure). Whenever lactic acidosis occurred, both mechanisms were present simultaneously and continuously. Especially, the latter mechanism had a very important role on it, and seemed to decide the prognosis of the patients with lactic acidosis. Therapy of lactic acidosis was very difficult. First of all, we tried to improve the circulatory failure and severe acidemia (pH less than 7.20) not to fall into vicious cycle. Then, CAVH, if combined with alkali infusion, seemed to be the most useful technique in managing lactic acidosis with ARF.     

Correlation between epidermal growth factor receptor concentration and the growth of human gastric cancer xenografts in nude mice.

Seven human gastric cancer xenografts with different concentrations of EGF receptor were established in nude mice. The expression of EGF receptor in the tumors was demonstrated by Western blotting with anti-EGF receptor antibody, binding assay with 125I-EGF and immunohistochemistry with anti-EGF receptor antibody. Western blotting revealed EGF receptor doublet bands at molecular masses of 150 KDa and 170 KDa in all of the samples. The concentration of 125I-EGF binding activity in the tumors ranged from 36.0 to 11,000 fmol/mg protein, with a mean of 345 fmol/mg protein. EGF receptor was also demonstrated immunohistochemically on the apical border of the glands and the cell membrane of the tumor cells. There seemed to be a close correlation between the concentration of 125I-EGF binding activity and the doubling time of these tumors in nude mice (gamma = -0.68). However, no definite correlation was observed between EGF ligand binding and histological features of intestinal type or diffuse type. The expression of EGF receptor appears to facilitate the growth of human gastric cancer xenografts in nude mice.