Studies on the absorption of elemental diets containing "small peptides" as a nitrogen source

Previous studies have shown that small peptides (di-or tri-peptide) are more rapidly and more evenly absorbed through the small intestine than free amino acid mixture of the same amino acid composition. Since a method to produce protein hydrolysate rich in di-or tri-peptide (SP) was developed, absorption studies were performed to ascertain if the SP shows superior efficiency in absorption to the free amino acid mixture (AA) and large peptide (LP) of the same amino acid composition. A practical elemental diet which contained SP as a nitrogen source, was made (SP-ED) and the absorption rates of nitrogen, carbohydrate and water were studied using dog Thiry-Vella loop in comparison with ED prepared with AA (AA-ED) or LP (LP-ED) with the same amino acid composition. The results are as follows: 1) Absorption rates of nitrogen and water in SP were higher than in AA and LP, when the osmolarities of these solutions were not adjusted to the same level. 2) When the osmolarities of the solutions were adjusted to the same level using mannitol, the absorption rate of nitrogen was still the highest in SP. 3) Nitrogen absorption rate was significantly higher in SP-ED than in AA-ED and LP-ED and carbohydrates were absorbed to a significantly greater extent from the SP-ED than from the AA-ED. These results indicate that small peptides are suitable for use as the nitrogen source for ED.     

Expression of epidermal growth factor and fibroblast growth factor in human hepatocellular carcinoma: an immunohistochemical study.

Expression of epidermal growth factor (EGF) and fibroblast growth factor (FGF) was examined in 56 patients with hepatocellular carcinoma (HCC) using an immunohistochemical method. EGF and FGF were expressed on carcinoma cells in 14 (25%) and 23 cases (41%), respectively. In the 23 FGF-positive cases, 11 cases were positive for both acidic and basic FGF, while 18 were positive for acidic FGF, and 16 were positive for basic FGF. In non-cancerous hepatic tissues, FGF was weakly positive in macrophages, hepatocytes and vascular endothelial cells in some cases, while EGF was totally negative. There were no significant correlations between the expression of EGF or FGF on carcinoma cells and the various clinicopathologic factors examined. These data suggest that EGF and FGF are produced by human HCC cells in vivo. The roles of the expression of these growth factors in the development and progression of HCC remain only speculative.     

Strain Difference of Susceptibility to 4-Nitroquinoline 1-Oxide-induced Tongue Carcinoma in Rats

Strain difference of susceptibility to 4-nitroquinoline 1-oxide (4NQO)-induced squamous cell carcinomas of the tongue among Dark-Agouti, Long-Evans, Sprague-Dawley, ACI/Ms, Fischer 344, Donryu and Wistar/Furth rats was surveyed by evaluating the survival times, incidences and sizes of developed tumors as markers of susceptibility. Administration of 4NQO dissolved in drinking water induced squamous cell carcinomas in various sites of the upper digestive tract mucosa of all the experimental male and female rats of the seven strains. Regarding the mean survival times, Wistar/Furth rats survived much longer than any other strain of rats, and Dark-Agouti showed the shortest survival. The incidence of large, mass-type carcinomas of the tongue of Dark-Agouti rats was higher than in any other strain of rats, while that of Wistar/Furth rats was the lowest. Subsequently the mitotic activity and bromodeoxyuridine incorporation in the tongue epithelium of Dark-Agouti and Wistar/Furth rats were estimated after a short-term administration of 4NQO. There was a pronounced difference between the two strains of rats, because the proliferative responses of the tongue epithelium of Dark-Agouti rats to the 4NQO stimulation were much higher than those of Wistar/Furth rats. These results indicated that there are marked differences in the susceptibility to 4NQO-induced tongue carcinoma among the seven strains of rats, and that Dark-Agouti and Wistar/Furth rats could be useful as models of highly and poorly susceptible strains, respectively, for further genetic analysis.     

Temporal and spatial expression of transforming growth factor-β in the healing patellar ligament of the rat

We investigated the temporal and spatial expression of transforming growth factor-β in the healing patellar ligament of the rat by immunohistochemistry. The mid-portion of the medial half of the patellar ligament in 14-week-old male Wistar rats was cut transversely with a scalpel. On day 1 after ligament injury, diffuse staining for transforming growth factor-β was observed in the extracellular matrix filling the wound, and the staining in the adjacent ligament tissue was as weak as it was in the normal ligament. On day 3, the intensity of the diffuse extracellular staining decreased, and the staining was observed in correspondence with the cellular distribution in the wound site and in the adjacent uninjured ligament tissue. On day 7, the intense staining was widely distributed over the whole length of the ligament tissue. On day 28, the staining for transforming growth factor-β was still observed at the wound site and in the adjacent uninjured ligament tissue, where the staining was reduced in intensity but still stronger than it was in the normal ligament. On day 56, the expression of transforming growth factor-β was still detectable at the wound site: however, in the adjacent uninjured ligament tissue, it had almost subsided to the normal level. The results of the present study suggest that ligament healing may be accompanied by extensive changes in the expression of transforming growth factor-β over the whole length of ligament tissue.     

Excursion of the flexor digitorum profundus tendon: a kinematic study of the human and canine digits

The most common problem following primary flexor tendon repair is the failure of the tendon apparatus to glide, secondary to the formation of adhesions. Early motion following tendon repair has been shown to be effective in reducing adhesions between the tendon and the surrounding sheath. Therefore, it is important to determine the amount of flexor tendon excursion along the digit during joint motion. In this study, the excursion between the flexor digitorum profundus (FDP) tendon and the sheath was examined in both human and canine digits. Based on roentgenographic measurements and joint kinematic analysis, the motion of the bones, the FDP tendon, and the sheath were measured with respect to joint rotations. It was found that the canine flexor tendon apparatus behaved similarly to that of the human for the motions studied. The amount of tendon excursion was very small in regions distal to the joint in motion (approximately 0.1 mm/10 degrees of joint rotation). There was little displacement of the sheath (0.2-0.3 mm), except at the metacarpal joint region during metacarpophalangeal (MCP) joint motion and at the proximal interphalangeal (PIP) joint region during PIP joint motion. Tendon excursion relative to the tendon sheath was the largest in zone II during PIP joint rotation (1.7 mm/10 degrees of joint rotation). These results suggest that PIP joint motion may be most effective in reducing adhesions following tendon repair in zone II.     

Chymase participates in chronic dermatitis by inducing eosinophil infiltration

An epicutaneous application of 2,4-dinitrofluorobenzene (DNFB) to a mouse ear caused a transient skin swelling, and the repetition of the challenge enlarged the contact dermatitis. The repeated challenge with DNFB also induced eosinophil infiltration on the application site. Administration of a chymase inhibitor significantly inhibited the ear swelling as well as eosinophil accumulation. An intradermal injection of human chymase to the mouse ear also elicited transient skin swelling and eosinophil infiltration, both of which were augmented in proportion to the number of injections. Human serum albumin and heat-inactivated chymase failed to induce such skin reactions, suggesting the participation of proteolytic activity of the enzyme. In addition, chymase stimulated eosinophil migration in vitro in a concentration-dependent manner. Taken together, these observations suggest that mast cell chymase may contribute to development of the DNFB-induced dermatitis, probably by promoting eosinophil infiltration. It is therefore possible that chymase plays a role in pathogenesis of chronic dermatitis such as atopic dermatitis.     

An Epstein-Barr virus-producer line Akata: Establishment of the cell line and analysis of viral DNA

An Epstein-Barr virus (EBV)-producer line, designated Akata, was established from a Japanese patient with Burkitt's lymphoma. The Akata line possessed the Burkitt's-type chromosome translocation, t(8q-; 14q+), and was derived from the tumor cell. Akata cells produced a large quantity of transforming virus upon treatment of cells with anti-immunoglobulin antibodies (Takada, 1984). Southern blot analysis of viral DNA indicated that the Akata EBV is nondefective and more representative of wild-type viruses. Akata cells should be useful as a source of EBV.     

Serum cholesterol levels as a risk factor of cardiovascular disease

By summing up a series of epidemiological evidence a continuous elevation of total serum cholesterol, especially LDL-cholesterol, leads atherosclerosis and causes the narrowing or occlusion of coronary artery which introduces acute myocardial infarction or angina pectoris in the heart. In the brain, it is a risk factor for cerebral thrombosis. On the other hand, a lower level, 160 mg/dl or less of total serum cholesterol relates with the higher incidence of cerebral hemorrhage or subarachnoid hemorrhage, but still with the lower incidence of ischemic heart disease. It is concluded that the higher the total serum cholesterol level and the longer the period of continuous elevation is, the higher the incidence of ischemic heart disease. And there is a U-shape relationship between the level of serum cholesterol and cerebrovascular disease as a whole with a nadir around 160 to 200 mg/dl which means an optimal range of total serum cholesterol. A subject with total serum cholesterol over the optimal level may need some sort of modification in his daily life, in eating or physical exercise but not necessarily requires any pharmacological therapy.