Comparison of absorption of erythorbic acid and ascorbic acid in guinea pig small intestine.

Both the ascorbic acid (AsA) and erythorbic acid (ErA) absorption in the small intestine of guinea pigs were determined by the perfusion of the small intestine using isotonic phosphate buffer recycled in situ. The absorption rate of AsA in the small intestine of guinea pigs was higher than that of ErA; however, Km of AsA absorption was lower than that of ErA in normal guinea pigs. In AsA-deficient guinea pigs, the absorption rates of both AsA and ErA were higher than those in normal ones. The absorption of AsA and ErA in the small intestine of guinea pigs was inhibited by ouabain. Furthermore, AsA and ErA inhibited each other's absorption. Based on the results, the net amount of the absorbed ErA in the small intestine may be lower than that of AsA, and ErA absorption mechanism seemed to be similar to that of AsA. The absorption rate of both AsA and ErA in the small intestine of guinea pig might be dependent on the AsA level in the tissues.     

Solitary cardiac metastasis of rectal adenocarcinoma

Solitary cardiac metastasis is rarely recognized. We report a case of solitary cardiac metastasis from a rectal adenocarcinoma that was manifested as superior vena cava (SVC) syndrome. Invasion of the deep cardiac structures was so severe that only its palliative resection and right atrial reconstruction were performed using a cardiopulmonary bypass to release the SVC obstruction. The postoperative course was uneventful and the patient was discharged home without any complications. Adjuvant chemotherapy could not be performed because of the renal dysfunction. Eleven months later, the patient died from multiple metastasis of adenocarcinoma. Even though the surgery was not curative, it might be effective for release from symptoms and for elongating life expectancy.     

Preoperative diagnosis of malignant melanoma using the touch-fluorescence method

We have developed a touch-fluorescence method using preparations from the outer surface of elevated and ulcerative malignant melanoma lesions. This method allows the demonstration of the melanogenic activity of melanoma cells within 30 min and has made it possible to definitively diagnose a lesion as malignant melanoma at the initial examination. In 21 cases clinically diagnosed as typical melanoma, 17 were definitively diagnosed as melanoma from the touch-fluorescence microscopic findings. Of the four cases in which no fluorescent tumor cells were found, two proved not to be melanoma. There was some correlation between the morbid types of primary melanoma and the configuration of fluorescent melanoma cells, the main cellular configuration of superficial spreading melanoma being round whereas that of nodular melanoma and acral lentigenous melanoma was pleomorphic. Based on the above results, this method was concluded to be extremely reliable for the preoperative diagnosis of elevated and ulcerative lesions of malignant melanomas, which are sometimes difficult to diagnose.     

Characterization of protein kinase C activities in postsynaptic density fractions prepared from cerebral cortex, hippocampus, and cerebellum

Protein kinase C (PKC) activities, especially, substrates and PKC isozymes, associated with postsynaptic density (PSD) fractions isolated from rat cerebral cortex, hippocampus, or cerebellum were investigated. The 17kM_r major substrate for PKC was associated with PSD fractions prepared from cerebral cortex and hippocampus, and several substrates including 18kM_r, protein were associated with PSD fraction isolated from cerebellum. The content of 17kM_r, substrate was extremely low in the PSD fraction prepared from cerebellum. PKCs-β and λ were associated with PSD fractions and PKC-α was virtually absent in the fraction prepared from the three different regions of the brain. All of PKCs-α, β, and λ were associated with synaptosome fractions. The 36kM_r bands immunoreactive with anti-PKC-β antibody, probably degradation products of native PKC-β, were detected in both the PSD and synaptosome fractions from the three regions, and the ratio of the degradation fragments to native PKC molecule was higher in PSD fractions than in synaptosome fractions. The results suggest postsynaptic roles of PKCs-β and λ and involvement of proteolytic activation of PKC-β in the postsynaptic signal processing.     

Genotoxicity of genetic recombinant human erythropoietin in a novel test system

The nude (athymic) mouse was used as a novel test system forthe evaluation of genotoxicity of genetic recombinant humanerythropoietin (rhEPO). A fibroblast cell line derived fromthe kidneys of baby hamsters, BHK-21, or a subclone of BHK-21transfected with an expression vector containing the human EPOgene named BXE cells, were implanted innude mice. The concentrationof EPO in the plasma of mice bearing BXE increased in relationto the increase in the weight of the tumor formed from growthof BXE cells. Increased values of hematocrit (Ht), ratio ofreticulocytes to erythrocytes (RET ratio) and the number ofred blood cells in mice bearing BXE indicated that excessivehematopoiesis was occuring in the host. However, the concentrationsof EPO in the plasma of the mice bearing BHK-21 did not increasein relation to the cell mass and consequently the Ht valuesand RET ratios in these mice were not affected. Marked increasesin the frequencies of micronucleated polychromatic erythrocytes(MNPCE) and micronucleated RET (MNRET) were noted in the micebearing BXE, although no chromosomal aberrations were foundin the spleen and marrow cells of the same mice. The increasedlevels of RET, MNRET and MNPCE seemed to result from accelerationof erythroblastic maturation and proliferation by rhEPO. Itis therefore concluded that errors in the processes of enucleationor differentiation of erythrocytes should be equally consideredas possible mechanisms alongside errors in genetic repair processesfor the increased frequencies of MNPCE and MNRET.     

A Prospective Comparative Trial of a Gonadotropin-Releasing Hormone Analogue with Clomiphene Citrate for the Treatment of Oligoasthenozoospermia

Background: We undertook a prospective trial to compare the efficacy and adverse effects of a gonadotropin releasing-hormone analogue (CnRHa) and clomiphene therapy for idiopathic normogonadotropic oligoasthenozoospermia (INOA).
Methods: Between January and December 1995, 44 newly-diagnosed INOA patients were randomly allocated to treatment with GnRHa or clomiphene citrate. Efficacy was assessed by measuring changes in semen parameters prior to and after 3 months of treatment. Twenty-three INOA patients underwent GnRHa therapy with 15 μg of diluted buserelin acetate given once a day intranasally, and 21 INOA patients were treated with 50 μg of clomiphene citrate daily by oral administration.
Results: The mean sperm density in the GnRHa group increased from 1 6.1 times 10⁶/mL to 26.9 times 10⁶/ml(P < 0.05), while the mean sperm density did not change significantly in the group treated with clomiphene. Similarly, the mean sperm motility increased from 35.9% to 43.9% in the GnRHa group (P < 0.05), but did not significantly change in the clomiphene group. No adverse effects were observed in either group.
Conclusion: This GnRHa treatment protocol can be administered as an outpatient and is hoped to benefit INOA patients.     

Long-term effect of radical gastrectomy on nutrition and immunity

The long-term effects of gastrectomy on the nutritional and immunologic status were prospectively studied in 79 gastric cancer patients who underwent curative gastrectomy and were followed by us after operation for an average of 5 years and 3 months. The percent of actual weight to pre-illness normal weight was lower than 95% in 80% of all study patients. Retinol binding protein, prealbumin, and albumin were lower than normal in 17%, 26%, and 26% of the patients, respectively. The mean values of the percent normal weight, retinol binding protein, and prealbumin were significantly lower in the totally gastrectomized patients than in the subtotally gastrectomized ones (P<0.01). The procedures of reconstruction did not affect the nutritional status except for the prealbumin level which was significantly decreased in Roux-en-Y cases than in interposed cases of totally gastrectomized patients. Cell-mediated immunological alterations after gastrectomy were observed in 31%, 37%, and 71% of all patients for OKT3 subpopulation, OKT4/OKT8 ratio, and blastogenesis by phytohemagglutinin, respectively. A multivariate analysis revealed that the long-term immunity of the gastrectomized patients after operation was not affected by the levels of albumin and rapid turnover proteins but by the splenectomy and weight loss they underwent.     

Effect of graded doses of erythorbic acid on ascorbic acid content of tissues of guinea pigs

The effect of graded doses of erythorbic acid (ErA) on the content of ascorbic acid (AsA) in the tissues of guinea pigs administered AsA was studied. The guinea pigs were administered 5 mg AsA and 1, 5, 20, and 100 mg ErA; or 1 mg AsA and 1 and 20 mg ErA; or 20 mg AsA and 20 mg ErA for 16 days. The animals were then sacrificed, and the liver, adrenal glands, spleen, and kidneys were removed to determine the contents of AsA and ErA by using HPLC. The content of AsA in the tissues of the animals administered less than 5 mg ErA together with 5 mg AsA was not significantly different from that of the animals administered 5 mg AsA. The administration of 100 mg ErA together with 5 mg AsA caused a decrease in the amount of AsA in the tissues. The content of AsA in the tissues of the animals administered ErA together with 1 mg AsA was not significantly different from that of the animals administered 1 mg AsA. In the case of animals administered an equal amount of both AsA and ErA, the AsA tissue content was consistently much higher than that of ErA. These results indicated that the administration of relatively small amounts of ErA did not appear to reduce the availability of AsA.