Amino acids and peptides. XXXI. Preparation of analogs of the laminin-related peptide YIGSR and their inhibitory effect on experimental metastasis.

Analogs of a partial sequence peptide of laminin, i.e., Tyr-Ile-Gly-Ser-Arg (YIGSR) analogs and Cys-Asp-Pro-Gly-Tyr-Ile-Gly-Ser-Arg (CDPGYIGSR) analogs, were prepared by the solid-phase method and their inhibitory effects on experimental metastasis of B16-BL6 melanoma cells were examined. YIGSR analogs in which Ile was replaced by other hydrophobic amino acids (Met, Leu, Phe) were inhibitory. Cys-containing analogs of YIGSR were also prepared, but were less active than the parent peptide, YIGSR. Among them, CYIGSR was easily oxidized to form a disulfide bond. A Cys-containing YIGSR analog cyclized through a disulfide bond, cyclo(CYIGSRC)G, was prepared. The disulfide bond formation was performed on the resin by the silyl chloride-sulfoxide method and by the iodine oxidation method. The yield of the silyl chloride-sulfoxide method was much better than that of the iodine oxidation method.

Amino acids and peptides. XXX. Preparation of Arg-Gly-Asp (RGD) hybrids with poly(ethylene glycol) analogs and their antimetastatic effect.

Hybrids of a fibronectin-related peptide[Arg-Gly-Asp (RGD)] with poly(ethylene glycol) (PEG) analogs were prepared by a simple and easy procedure. Two amino-PEG analogs were used as carriers for hybrid formation of the RGD. One was poly(oxyethylene)dipropylamine and the other was Jeffamine ED type, which has branched chains. RGD peptides were formed stepwise on PEG analogs by the diisopropylcarbodiimide method. The synthetic intermediates were easily purified by molecular-sieve gel chromatography and the final products were purified by molecular-sieve gel chromatography, followed by HPLC. This simple and easy preparation procedure using molecular-sieve gel chromatography for purification of synthetic intermediates is advantageous for the preparation of peptide-polymer hybrids. We found that PEG is stable to HF treatment at 0 degree C for 1 h. The inhibitory effect of the RGD hybrids on experimental metastasis of B16-BL6 was examined in mice. The Jeffamine type hybrid showed no inhibitory effect at the dose of 1 mg/mouse, but poly(oxyethylene)dipropylamine type hybrid was inhibitory at the same dose. The effect of the latter hybrid was about the same as that of 1 mg of RGD. One mg of the hybrid contains 0.18 mumol of RGD and 1 mg of RGD is 2.38 mumol. Thus it can be said that the inhibitory effect of RGD was potentiated by hybrid formation with poly(oxyethylene)diisopropylamine.

Amino acids and peptides. XXXII: A bifunctional poly(ethylene glycol) hybrid of fibronectin-related peptides.

An amino acid type poly(ethylene glycol) (aaPPEG) was prepared and its application to a drug carrier was examined. The peptides, Arg-Gly-Asp (RGD) and Glu-Ile-Leu-Asp-Val (EILDV) which were reported as active fragments of Fibronectin (a cell adhesion protein), were conjugated with aaPEG (molecular weight, 10,000). The hybrid, RGD-aaPEG-EILDV, was prepared by a combination of the solid-phase method and the solution method. Antiadhesive activity of the peptides was not lost by its hybrid formation with the large aaPEG molecule. A mixture of RGD (0.43 mmol) and EILDV (0.43 mmol) did not demonstrate an antiadhesive effect, but the hybrid containing 0.43 mmol of each peptide did exhibit this effect.

[Neurophysiological studies of minamata disease with HTLV-I associated myelopathy--a case report].

In both Minamata disease (MD) and HTLV-I associated myelopathy (HAM), sensory disturbance is one of the most characteristic clinical symptoms. We have examined median nerve SSEPs (MN-SEP) and posterior tibial nerve SEPs (PTN-SEP) of both patient groups, and reported their specific abnormalities. MN-SEP of MD patients never showed any conduction delay nor conduction block at the cervical cord. However, they demonstrated the initial positive cortical response with low amplitude instead of the initial negative response (N20) seen in healthy subjects. In PTN-SEP, MD patients showed the initial positive cortical response with significantly shorter latency and lower amplitude than healthy subjects. These findings have never been seen in any other diseases. On the other hand, the conduction delay and conduction block on peripheral nerve, spinal cord and/or intracranial sensory tracts have been demonstrated in many cases with HAM. The patient was a 60-year-old man. About 40 years ago, he suffered with typical clinical symptoms of MD such as cerebellar ataxia, intention tremor and sensory disturbance of upper and lower extremities, and then his condition was complicated with progressive spastic paraplegia and urinary bladder dysfunction since 30 years ago. Both MN-SEP and PTN-SEP were studied so that we could make the electrophysiological differential diagnosis of MD and HAM. His MN-SEP indicated both the conduction delay at his cervical cord and intracranial sensory tract and the initial positive potential from cephalic recording. Furthermore, his PTN-SEP demonstrated severe conduction block at the spinal cord and neither cervical response (N28) nor cortical response (P37) was evoked. In conclusion, the clinical electrophysiologic studies supported our notion that the case might be affected with both MD and HAM.

Amino acids and peptides. XXVII. Solid phase synthesis of fibrinogen-related peptides with disulfide bond formed on solid support.

Fibrinogen-related peptides, monomeric cyclic peptides through a disulfide bond [cyclo(H-Cys-Arg-Gly-Asp-Phe-Cys-NH2), cyclo(H-Cys-Arg-Gly-Asp-Phe-Cys-Gly-NH2), cyclo(H-Cys-Arg-Gly-Asp-Cys-NH2) and cyclo(H-Cys-Arg-Gly-Asp-Cys-Gly-NH2)], were prepared by the solid phase method with disulfide bond formation on the solid support. The acetamidomethyl group was used for protection of the thiol group of Cys and synthetic peptide-resins were treated with iodine to give the disulfide bond. Monomeric cyclic peptides were obtained as main products. Purified S-acetamidomethylated peptides were also oxidized with iodine, but the desired materials could not be isolated by HPLC. The disulfide formation from S-acetamidomethylcysteine-containing peptide resin by iodine treatment on the solid support was more effective than that from S-acetamidomethylcysteine-containing peptide. The inhibitory effect of the cyclic peptides on platelet aggregation were much more potent than that of H-Arg-Gly-Asp-NH2.

Amino acids and peptides. XXVI. Laminin-related peptide poly(ethylene glycol) hybrids and their inhibitory effect on experimental metastasis.

Laminin-related peptide poly(ethylene glycol) hybrid, Tyr-Ile-Gly-Ser-Arg-aminopoly(ethylene glycol) was prepared by the solution method and carboxylated poly(ethylene glycol)-Tyr-Ile-Gly-Ser-Arg was prepared by the solid phase method. Their inhibitory effects on experimental tumor metastasis were examined in mice. The inhibitory effect of Tyr-Ile-Gly-Ser-Arg was significantly potentiated by hybrid formation with poly(ethylene glycol) either at amino- or carboxyl terminals of the peptide. Of the hybrids, Tyr-Ile-Gly-Ser-Arg-amino(polyethylene glycol) #6000 hybrid exhibited about 10 times more potent anti-metastatic effect than the peptide itself. The inhibitory effect of a mixture of the carboxylated poly(ethylene glycol) hybrid and Arg-Gly-Asp-aminopoly(ethylene glycol) hybrid also exhibited an inhibitory effect.

Cytomegalovirus vasculitis accompanied by an exuberant fibroblastic reaction in the intestine of an AIDS patient.

A case of cytomegalovirus (CMV) vasculitis in the intestine of a patient with acquired immune deficiency syndrome (AIDS) is reported. The distal jejunum and ileum had multiple well-demarcated mucosal ulcers and microscopic examination revealed an unusual, exuberant fibroblastic proliferation in the ulcer base. Amidst these fibroblasts, there were several small blood vessels of which the endothelial cells contained cytomegalic inclusion bodies. The lesion showed a Kaposi's sarcoma-like appearance, but spindle cells were negative in immunostaining for factor VIII-related antigen or Ulex europaeus agglutinin-1. Although the CMV infection was observed in almost all organs, the exuberant fibroblastic proliferation seen in the intestine was not found in other organs. This lesion might represent a peculiar reaction of the immunologically compromised host to the CMV in the intestinal blood vessels.

[An autopsy case of multiple myeloma accompanied by extensive nodular infiltration into the extraskeletal tissue].

Discussed is the case of a 41-year-old Japanese man dead at 4 months after start of his clinical course of multiple myeloma of the Bence-Jones protein lambda type of the skull. Autopsy findings revealed that atypical plasmacytes had infiltrated extensively into the testes, the retroperitoneum, including the pancreas and the renal pelvis, the bilateral pleura, the right subclavian soft tissue, and the meningism, but not to the liver, spleen, and lymph nodes. In both testes, which weighted 120 g and 100 g, respectively, myeloma cells were found disseminated throughout the testicular tissue. Such a testicular involvement in cases of a multiple myeloma is extremely rare. The pertinent literature also is reviewed.

[Lactating mammary tissue in a mature cystic teratoma of the ovary].

Discussed is a mature cystic teratoma that was surgically removed from the left ovary, said teratoma containing lactating mammary tissue of a 30-year-old Japanese lady, primigravida and in her 36th gestation week. The tumor measuring 3 X 3 X 3 cm, was accidently found when she underwent a cesarian section. In the lactating glandular tissue of the teratoma, the application of an anti-alpha-lactalbumin serum revealed diffuse and/or reticular cytoplasmic stainings of almost all the luminal cells and secretory materials. Further, myoepitheliall cells were clearly visualized with anti-actin serum. References are made to 2 other case reports of similar tumoral tissue.

Influence of strain and sex on the local development of mammary tumors induced by direct application of DMBA powder to rat mammary glands.

In order to determine the influence of strain and sex on local carcinogenesis in rat mammary tissue, 1 mg of 7,12-dimethylbenz(a)anthracene (DMBA) was dusted directly onto the exposed mammary gland of 30-day-old Long-Evans (L-E) rats and Sprague-Dawley (S-D) rats. The experiment was terminated 28 weeks after application of the carcinogen. Tumors measuring between 1 and 2 cm in diameter were harvested from female L-E rats with high frequency (85%) and long latency (mean: 23.7 weeks after DMBA dusting), and from female S-D rats with extremely high frequency (98%) and short latency (16.7 weeks). Male rats of both strains were almost identically much less susceptible to DMBA (L-E; 55%, 25.0 weeks, S-D; 53%, 23.9 weeks). Ovariectomized S-D (47%, 24.9 weeks) and orchiectomized S-D (30%, 24.8 weeks) rats, which were gonadectomized at 30 days of age, respectively, were also much less susceptible. A variety of histologies, mostly malignant epithelial, mesenchymal or mixed tumors, were noted in each group. The carcinomatous response in the mammary tissue was much higher in female S-D (96%) than in female L-E (50%) rats, and very low in male and gonadectomized rats (10-20%). In contrast, the sarcomatous response in the mammary tissue was moderate in female and male L-E and male S-D (43-50%) rats, and low in the other groups (15-29%).