Protein Synthesis in Yolk Sac Tumor: Histochemical Studies of Human and Rat Yolk Sac Tumor

Synthesis of various serum proteins, such as albumin, prealbumin, α₁-antitrypsin, transferrin and α-fetoprotein, by human and rat yolk sac tumors was studied by indirect immunofluorescence and immunoperoxidase techniques. These serum proteins were found to be present in the cytoplasm of tumor cells forming the lining of vitelline cysts, as well as Schiller-Duval bodies and vacuolated meshwork on histological sections. Two of these tumors were cultured. Immunopathological studies revealed that albumin, prealbumin, α₁-antitrypsin, transferrin and α-fetoprotein were found in the cytoplasm of these cultured tumor cells. The immunofluorescence of these proteins was also found on the PAS-positive granules, which existed intra- and extra-cellularly.
The ability to synthesize these serum proteins of these tumor cells was not affected by tissue culture and was maintained during subcloning.
It was demonstrated by electron microscope ferritin antibody technique that α-fetoprotein was mainly synthesized on the ribosomes of the rough endoplasmic reticula of rat yolk sac tumor cells.     

Testosterone inhibits immunoglobulin production by human peripheral blood mononuclear cells

We studied the in vitro effect of testosterone on spontaneous immunoglobulin production by human peripheral blood mononuclear cells (PBMC). Testosterone inhibited IgG and IgM production by PBMC both from males and females. The inhibitory effect of testosterone was revealed at doses more than 1 nm, increased dose-dependently, and reached a plateau at 100 nm. At doses <1000 nm, testosterone did not reduce cell viability. Testosterone treatment reduced IgG production by 59.0% and that of IgM by 61.3% compared with control. Immunoglobulin production by B cells was also suppressed by testosterone, though the magnitude of the suppressive effect on B cells was lower than that on whole PBMC; testosterone-induced decrease of IgG production compared with control was 26.9% and that of IgM was 24.9%. Exogenous IL-6 partially restored the impaired immunoglobulin production of testosterone-treated PBMC; IgG production in testosterone culture was increased by IL-6 from 35.6% to 66.5% of control and that of IgM was also increased from 38.9% to 71.2%, respectively. Testosterone treatment reduced IL-6 production of monocytes by 78.4% compared with control, but neither affected that of T cells or B cells. These results suggest that testosterone may suppress immunoglobulin production of human PBMC directly by inhibiting B cell activity and indirectly by reducing IL-6 production of monocytes. It is thus indicated that this hormone may have protective and therapeutic effects on human autoimmune diseases.     

The Preclinical Safety Evaluation of Human Monoclonal Antibody against Cytomegalovirus

The human monoclonal antibody against cytomegalovinis (Mab C23)was examined pharmacokinetically and toxicologically as partof the preclinical studies prior to approval for human use.Rats given repeated intravenous administrations of Mab C23 producedno antibodies against Mab C23 and maintained a blood Mab C23level in a dose-dependent manner. However, pregnant rabbitsproduced antibodies against Mab C23. The half-life of Mab C23in plasma was 15.9 days in rats, which was similar to that ofnormal human serum -globulin (NHSG). Neither behavioral effectsnor circulatory disturbance was found in mice, rats, and dogseven after a single intravenous injection of 100 or 200 mg/kg,which corresponds to 50 or 100 times the intended clinical dosage.The repeated doses of 2, 10, or 20 mg/kg of Mab C23 on six occasionswith 1- or 2-week intervals elicited a transient decrease inleukocyte counts in rats given 10 or 20 mg/kg, but no adverseeffects in cynomolgus monkeys. Mab C23 did not cause any reproductiveor developmental toxicity when administered to rats and rabbitsat dose levels of 20 mg/kg or less. However, pregnant animalsshowed lower plasma levels of Mab C23 than non-pregnant animals.The chromosomal aberration test disclosed no clastogenicityin human lymphocytes. An immunostaining for Mab C23 revealedno localizations in several tissues of cynomolgus monkeys givenintravenous doses of Mab C23. The preclinical safety evaluationin animals other than rabbits, which produced no antibodiesagainst Mab C23, showed that the behavior of Mab C23 is pharmacokineticallysimilar to that of NHSG and is as safe as NHSG, which has longbeen used as a biological agent. However, because there wasa difference in blood levels of Mab C23 between pregnant andnonpregnant animals, its clinical administration to pregnantpatients should differ from that to non-pregnant patients.     

Serum hyaluronic acid reflects the effect of interferon treatment on hepatic fibrosis in patients with chronic hepatitis C

Changes in serum hyaluronic acid (HA) in 35 patients treated with interferon (IFN) were studied and the histological change in fibrosis was analysed. Serum HA levels and hepatitis C virus (HCV) RNA were followed from the start of therapy to 12 months after completion of treatment. Histological changes in pre- and post-treatment liver biopsies were assessed using a modified Knodell's scoring system. The serum levels of HA (r = 0.79; P<0.0001) correlated with the degree of fibrosis more closely than with that of amino terminal peptides of type III procollagen (PIIIP; r = 0.45; P<0.05) or type IV collagen (IV-C; r = 0.42; P<0.05). Only complete responders (CR) had a significant decrease in serum levels of HA and IV-C (P<0.05), in parallel with histological improvement (P<0.01). Neither partial responders (PR) nor non-responders (NR) had significant changes in histological scores and in serum levels of fibrotic markers. Significant differences were observed between CR and NR, both in HA levels (P<0.01) and PIIIP levels (P<0.05) 12 months after the cessation of treatment. These results suggest that serum HA is an indicator of the extent of fibrosis in chronic hepatitis C. Serial determinations of serum HA levels may be of use for monitoring the histological response of hepatic fibrosis to IFN treatment in chronic hepatitis C.     

Urine Growth Hormone Determinations Compared with Other Methods in the Assessment of Growth Hormone Secretion

Okuno, A., Yano, K., Itoh, Y., Hashida, S., Ishikawa, E., Mohri, Z-I. and Murakami, M. (Department of Paediatrics, Asahikawa Medical College, Hokkaido; Medical College of Miyazaki, Kiyotake, Miyazaki; and Research and Development Division, Sumitomo Pharmaceuticals Co Ltd, Hyogo, Japan). Urine growth hormone determinations compared with other methods in the assessment of growth hormone secretion. Acta Paediatr Scand [Suppl] 337:74, 1987.
Urinary excretion of hGH was studied in children with short stature using a sensitive sandwich enzyme immunoassay technique. Urinary hGH excretion, in terms of hGH: creatinine ratio, showed excellent correlation with the mean and peak hGH values during physiological and pharmacological tests. It seems that the urinary hGH levels reflect serum hGH profiles during the urine collection period. A border zone for the lower limits of normal hGH levels in the urine was 7.5–13.4 ng/g creatinine for the physiological test at night (from 2000 hours to 0600 hours) and 17.4–35.0 ng/g creatinine for the pharmacological tests. Assessment of hGH secretory status by the urinary hGH levels showed good agreement with the serum hGH response. Measurement of urinary hGH could be used as a diagnostic test for impaired hGH secretion, and the multiple blood drawing required in physiological and pharmacological tests might be replaced by urine sampling.     

Urinary uric acid excretion in term and premature infants

Objective : To clarify postnatal changes in urinary uric acid (UA) excretion in normal term infants and to examine the effects of prematurity or illness on the UA excretion.
Methodology : Measurements of urinary UA were performed in term and premature infants at the ages of 1 and 7 days and at 1 and 4 months, as well as at 7 months in term infants.
Results : Urinary UA levels were lowest on day 7 in term infants. The levels were highest on day 1 in premature infants and remained significantly higher compared to term babies during the first month of life. Respiratory failure requiring ventilation and oxygen supply resulted in further significant elevation of urinary UA in premature infants.
Conclusions : With the reference values obtained in the study reported here, urinary UA can now be used for the diagnosis and monitoring of inherited disorders of purine metabolism and for the assessment of oxygen radical insult to sick infants.