Urinary excretion of acid-soluble peptides in children with Duchenne muscular dystrophy

In order to investigate the validity of the hypothesis that acid-soluble peptides (ASP) in urinary excreta can be applied as an index of the protein catabolism of the whole body, we measured the urinary excretion of ASP in 46 normal children and in 18 children with Duchenne muscular dystrophy (DMD), in which continuous breakdown of skeletal muscle protein is presumed. The mean value of ASP in the children with DMD was significantly higher than that in normal controls. The concentration of ASP was correlated with that of 3-methylhistidine (3MH), which has been proposed as an index of muscle breakdown. This finding indicates that urinary ASP reflects the catabolism of body proteins. No correlation was observed between the concentration of ASP and that of 1-methylhistidine (1MH), which is used as an objective index of meat and fish ingestion. After the administration of bestatin, an inhibitor of leucine aminopeptidase, for 9 months, the urinary ASP concentration of children with DMD increased markedly. This increase is thought to have been directly caused by the bestatin itself. Urinary ASP is therefore apparently a more conveniently applied index of protein catabolism than is urinary 3MH, which requires the application of several restrictions. However, it should not be applied when the effect of bestatin administration is evident.     

A Case of Glucagonoma with Liver Metastasis: Complete Response to Dacarbazine

Abstract: We report a case of glucagonoma syndrome with liver metastasis, who responded completely to dacarbazine chemotherapy. A 77-year-old woman complained of itching skin eruptions (diagnosed as necrolytic migratory erythema) and weight loss. She was found to have glucose intolerance, anemia, hypoproteinemia and hyperglucagonemia. Abdominal CT and celiac arteriography showed a hypervascular tumor in the pancreatic tail and a metastatic tumor in the left hepatic lobe. Immunohistochemical examination of the metastatic liver tumor obtained by laparoscopic biopsy revealed the tumor cells to be positive for glucagon. The patient was treated with 20 courses of 300 mg/day intravenous dacarbazine for 5 consecutive days followed by a 4 week drug-free interval. No major side effects were noted. Treatment resulted in disappearance of the skin lesions and correction of anemia, glucose intolerance, hypoproteinemia and hyperglucagonemia. Follow-up abdominal CT showed complete resolution of both the primary pancreatic tumor and the metastatic liver tumor. We suggest that dacarbazine be considered as the treatment of choice for metastatic glucagonoma.     

Clinical Trial with Authentic Recombinant Somatropin in Japan

Recombinant somatropin, produced by recombinant DNA technology, was administered by injection in daily doses of 8 IU to six healthy young volunteers. Daily injection for 4 days did not cause any significant change in the results of physical examination, blood count or urinalysis. Non-esterified fatty acid levels increased significantly from 0.45 ± 0.16 to 1.08 ± 0.12 mEq/litre (mean SEM) at 4 hours after the first injection (p<0.001). Plasma IGF-1 levels increased from 0.80 ± 0.14 units/ml to 1.72 ± 0.50, 3.22 ± 1.02, 3.17 ± 1.20 and 3.63 ± 0.78 units/ml at 24 hours after each daily injection for 4 days (p<0.001). Plasma hGH reached peak levels at 3 hours after intramuscular injection of recombinant somatropin, 4 IU, and this peak value was 57.3 ± 2.8 ng/ml. A total of 21 patients with pituitary dwarfism were also treated with recombinant somatropin for 6 months at a dose of 0.5 IU/kg/week. Their heights increased by 2.2–5.0 cm during the 6 months of treatment, which was calculated to be equivalent to 4.4–10.0 cm/year with a mean growth rate of 7.4 ± 0.4 cm/year. Anti-hGH antibody with a titre of 10 was observed in two patients at the end of 6 months of treatment.     

Effects of human neonatal serum on DNA synthesis in suckling and adult rat hepatocytes in primary culture

The effect of human neonatal serum on DNA synthesis in suckling and adult rat hepatocytes in primary culture was investigated to characterize growth regulating factors of the liver in neonates and to confirm whether the stimulatory factor is human hepatocyte growth factor (hHGF). Neonatal serum stimulated DNA synthesis of both adult and suckling rat hepatocytes. The stimulatory effect was dose-dependent up to 20% in volume. The molecular weight of the stimulatory substance in neonatal serum was between 12 500 and 25 000, as estimated by gel filtration. Its activity was stable after heating at 56°C for 20 min, but was lost after heating at 90°C for 30 s, and easily passed through S- or heparin-Sepharose columns. The concentration of hHGF quantified by ELISA was too low to stimulate DNA synthesis in vitro. Biological and biochemical properties of the growth stimulatory activity in neonatal serum differed from that of hHGF. The presence of other growth factors in human neonatal serum for suckling and adult hepatocytes was suggested.     

EARLY STAGE OF DEVELOPMENT OF TRANSPLACENTALLY INDUCED GLIOMA WITH ETHYLNITROSOUREA IN RATS

Proliferative activity of possible preneoplastic cells (subependymal cells and glioblasts), early neoplastic cells and glioma cells induced by transplacental ethylnitrosourea (ENU) treatment in the rat was analysed by historadioautography and electron microscopy. Labeling index of ²H–thymidine in subependymal cells was the highest in the cerebrum of postnatal age, but no difference was observed between the normal and ENU treated groups. Thus, preneoplastic cells could not be distinguished from normal cells by morphology and proliferative activity. Focus of early neoplastic proliferation was composed of rather heterogenous and less differentiated cells, such as oligodendroblast–, glioblast– and subependymal cell–like cells, and preferentially located around the periventricular areas. Labeling index of early neoplastic proliferation was very low although the value gradually increased with age. Proliferative activity of glioma cells was higher than that of the early neoplastic cells and lower than subependymal cells, and further differed according to the degree of differentiation and morphological type. Finally, it is suggested that glioma might develop mainly through the differentiation from the focus of early neoplastic proliferation. ACTA PATHOL. JPN. 33: 237–247, 1983.     

Effects of Atrial Tachypacing on Symptoms and Blood Pressure in Severe Orthostatic Hypotension

The treatment of severe orthostatic hypotension (OH) is currently unsatisfactory and usually includes various pharmaceuticals to expand the blood volume and promote peripheral vasoconstriction. This study examined the short- and intermediate-term effects of atrial tachypacing (ATP) in patients with severe OH. We implanted dual chamber pacemakers in five patients (mean age 64 ± 7 years; four men), presenting with drug refractory, recurrent syncope, and OH due to panautonomic failure with severe chronotropic incompetence and absence of rate acceleration upon assuming the upright posture. The blood pressure (BP) was measured in the supine and passive upright postures, during sinus rhythm, and during atrial pacing at 90, 100, and 110 ppm, at 1 week and at discharge and/or 3 months after pacemaker implantation. Alleviation of symptoms and a delay in the fall in upright BP were observed in a single patient at 1 week, while at discharge and/or 3 months, all patients were markedly improved. The mean fall in systolic/diastolic BP between supine and upright position decreased from 73 ± 17/46 ± 13 mmHg before, to 56 ± 27/41 ± 30 mmHg during ATP. Although these changes did not reach statistical significance, the time required for the fall in BP lengthened significantly from 2.1 ± 0.2 minutes during sinus rhythm to 9.3 ± 1.5 minutes during ATP (P < 0.001).
Conclusions: At discharge and/or 3 months of follow-up, ATP conferred beneficial effects on orthostatic BP and alleviated symptoms in patients with severe OH. The short-term effects of ATP did not reflect its longer-term effects in four of the five patients.     

N-Acetyl-L-γ-glutamyl Derivatives of p-Nitroaniline,Sulphamethoxazole and Sulphamethizole for Kidney-specific Drug Delivery in Rats

Kidney-specific delivery of p-nitroaniline, sulphamethoxazole and sulphamethizole after either intravenous administration of the L-γ-glutamyl or N-acetyl-L-γ-glutamyl derivatives or the parent drugs has been examined in a rat model. All L-γ-glutamyl derivatives were converted to the corresponding parent drugs within 60 min whereas the N-acetyl-L-γ-glutamyl derivatives were fairly stable in the systemic circulation after parenteral administration. Concentrations of p-nitroaniline and sulphamethoxazole 20 min after administration of the parent drugs were somewhat higher in the kidney than in the liver and lung. The concentration of sulphamethizole in the kidney was dramatically higher than those in the hepatic and pulmonary tissue. Kidney-specific delivery of the drugs of interest was evaluated by determining the tissue concentrations of the released parent drug and the total drug levels (i.e. drug levels after hydrolysis of all conjugate to the parent drug). For L-γ-glutamyl-p-nitroaniline released renal levels of p-nitroaniline and total p-nitroaniline concentrations were both higher than those obtained after p-nitroaniline dosing. Use of L-γ-glutamylsulphamethoxazole resulted in higher total sulphamethoxazole concentrations in the kidney, but did not lead to an increase in released (unconjugated) sulphamethoxazole levels. In contrast, no kidney-selective distribution was observed for L-γ-glutamylsulphamethizole. Markedly increased kidney distribution was observed for both N-acetyl-L-γ-glutamyl-p-nitroaniline and N-acetyl-L-γ-glutamylsulpha-methoxazole and the liver and lung concentrations were correspondingly reduced in comparison with parent drug dosing. Use of the N-acetyl-L-γ-glutamyl-p-nitroaniline conjugate increased the concentration of p-nitroaniline in the kidney to the same extent as did L-γ-glutamyl-p-nitroaniline. In conclusion, N-acetyl-L-γ-glutamyl derivatization of certain compounds seems to be useful for kidney-specific ***drug delivery and preliminary data suggests that lipophilic drugs are better substrates than hydrophilic compounds. Results related to the selectivity of tissue distribution of the derivatives and species differences are discussed.