Plasma lipoproteins as targeting carriers to tumour tissues after administration of a lipophilic agent to mice

We synthesized 14C-warfarin hexadecyl ether (14C-WHE) by addition of a palmityl moiety to the hydroxyl group at the 4-position of 14C-warfarin, a compound known to bind to serum albumin. 14C-WHE preferentially bound to the lipoproteins, low-density lipoprotein (LDL) and high-density lipoprotein (HDL), in mouse plasma both in vitro and in vivo. 14C-Warfarin mainly concentrated in the liver immediately after intravenous administration to mice bearing M5076 sarcoma, and was found at only low concentrations in other tissues including the tumour. 14C-WHE highly distributed to the tumour, adrenal, and spleen, as well as the liver. These tissues coincided with those in which human 125I-LDL was vigorously incorporated. The results indicate that chemical modification of an agent, giving it high lipophilicity, will enable it to bind to lipoproteins after intravenous administration. These modifications raise the possibility of lipoproteins as endogenous targeting carriers into tumour cells, which have high LDL-receptor activity.

[Properties of a hemolysin produced by group C streptococci isolated from hemolytic streptococcal infection in formosan squirrels]

The hemolysin produced by group C streptococci (GCH) has an isoelectric point (pI) of 5.6 and a molecular weight of 32,000 and shows hemolytic activity in the absence of 2-mercaptoethanol (2-ME). The hemolytic activity of GCH was compared to that of streptolysin S (SLS). These hemolysins did not differ with respect to the binding and release of hemoglobin (Hb). GCH was bound to phospholipids on the membranes of target erythrocytes, followed by the rapid released of K+ and slow Hb release after a relatively long lag time. GCH showed a lower hemolytic efficiency than SLS, reflecting the fact that these hemolysins destroy erythrocytes by slightly different mechanisms.

Isolation and characterization of four novel bioactive peptides from a polychaete annelid, Perinereis vancaurica

Four bioactive peptides were purified from an extract of the polycheate annelid Perinereis vancaurica using an HPLC system for fractionation of the extract and the esophagus of the worm as bioassay system. The sequences of the peptides were determined to be H-Trp-Val-Val-Gly-Asp-Val-Gln-OH, H-Ala-Thr-Trp-Leu-Asp-Thr-OH, H-Trp-Met-Val-Gly-Asp-Val-Gln-OH and H-Phe-Tyr-Glu-Gly-Asp-Val-Pro-Tyr-OH. These peptides showed an excitatory activity on the esophagus of P. vancaurica. The excitatory effect of the second and fourth peptides was marked. They may be neuropeptides involved in regulation of the esophagus.

Azicemicins A and B, a new antimicrobial agent produced by Amycolatopsis. I. Taxonomy, fermentation, isolation, characterization and biological activities

A new structural class of the antibiotic, azicemicins A (1) and B (2) were isolated from the culture broth of the strain MJ126-NF4, which was closely related to Amycolatopsis sulphurea. They were purified by adsorption on Diaion HP-20, silica gel column chromatography and preparative TLC. The molecular formulas of 1 and 2 were determined to be C23H25O9N and C22H23O9N by HRFAB-MS, respectively. Azicemicins A and B have moderate growth inhibiting activity against Gram-positive bacteria and mycobacteria.

Tumor selective effect of RS-1541 (palmitoyl-rhizoxin) in M5076 sarcoma and host tissues in vivo

RS-1541 is a 13-O-palmitoyl derivative of rhizoxin, an inhibitor of tubulin polymerization. After intravenous administration of RS-1541 to mice bearing M5076 sarcoma, the maximal inhibitory effect of RS-1541 on DNA synthesis in the tumor was observed 24 h after administration, in agreement with the Cmax of rhizoxin produced from RS-1541, but not with the Cmax of RS-1541. The inhibitory effect after RS-1541 was much higher than that after rhizoxin itself. In the spleen, thymus and bone marrow, DNA synthesis was strongly inhibited by rhizoxin but not by RS-1541. After administration of RS-1541, no significant amounts of rhizoxin were detected in the tissues, except for the tumor. In acute toxicity tests, RS-1541 appeared to be less toxic than rhizoxin. These results indicate that RS-1541 possesses a high tumor-selective effect compared with rhizoxin, because of the selective production of rhizoxin in the tumor after administration of RS-1541.

[Therapy of acute empyema thoracis using thoracoscopic instruments]

Adequate pleural drainage is imperative for the treatment of acute empyema thoracis. But chest tube drainage sometimes cannot operate effectively if blocked by intrathoracic loculations. We successfully treated two cases of acute empyema thoracis using thoracoscopy. These patients had both undergone closed intercostal drainage, but the drains had not worked effectually. We performed thoracoscopy under local anesthesia. Loculations were broken by the thoracoscopic instruments. After pleural irrigation, chest tubes were properly positioned under thoracoscopy. It seems likely that thoracoscopic procedures may be useful in shortening the length of hospitalization and in improving lung re-expansion of acute empyema thoracis patients.

A variant alkaline phosphatase found in a case of gastric carcinoma with super bone scan

A rare case of gastric carcinoma associated with increased serum variant alkaline phosphatase activities is presented. A 54 year old man had extremely high serum alkaline phosphatase activity (18,607 U/l) with normal calcium and phosphate concentrations. His bone scintigram showed abnormal findings, 'super bone scan'. He was diagnosed as having Borrmann type 4 gastric carcinoma with diffuse bone metastases by examinations of the upper gastrointestinal tract and iliac bone biopsy. The alkaline phosphatase isozyme of this patient was of the bone type as measured by cellulose acetate membrane electrophoresis and the placenta/bone type by agarose gel electrophoresis, respectively. Immunoelectrophoresis and the immunoprecipitation method using monoclonal antibodies against various alkaline phosphatase isozymes, however, showed that his serum alkaline phosphatase had the liver type antigenicity. Furthermore, it had a larger molecular size and different sugar chains compared with the common liver type alkaline phosphatase. These findings suggest that a unique variant alkaline phosphatase was produced by gastric cancer cells, which is possibly an explanation for the high serum alkaline phosphatase activities in this patient.

A long surviving case of amyotrophic lateral sclerosis with atrophy of the frontal lobe: a comparison with the Mitsuyama type

A female patient with amyotrophic lateral sclerosis (ALS) showing psychiatric symptoms during her last 2 years of life is reported. Although pseudobulbar signs were seen at the onset of ALS and no respirator was used, the period from onset to death was rather long (9 years). The spinal lesions showed features common to ordinary ALS, while the marked atrophy with destructive changes throughout the frontal lobe seemed to be considerably more severe than that seen with either ordinary ALS or the Mitsuyama type of ALS. Since the clinical manifestations and histological characteristics are apparently different from those of the Mitsuyama type, our case may be a new nosological variant of ALS with psychiatric manifestations.

T cell receptor-mediated stimulation of mouse thymocytes induces up-regulation of the GM2/GD2 synthase gene

cDNA clones of the mouse GM2/GD2 synthase (EC 2.4.1.92) gene were isolated, and their analyses revealed that the protein has a type II transmembrane structure with 533 amino acids, which was very similar to the human homolog except for the mRNA size. The mRNA level in thymocytes dramatically increased after treatment with anti-CD3 monoclonal antibody, whereas it was not elevated when treated with prostaglandin E2. In situ hybridization showed an elevation of mRNA levels in medullar thymocytes, suggesting that T cell receptor-mediated signaling induces up-regulation of the GM2/GD2 synthase gene in mature thymocytes.

A novel approach to mode of action of cationic biocides: morphological effect on antibacterial activity

A new concept for the mode of action of cationic biocides is proposed in which the antibacterial activity of cationic disinfectants is ascribed essentially to molecular organizations of cations within aggregates, i.e. the activity is determined by the size of aggregates and number of active molecules comprising the aggregate. On the basis of the new concept, the morphological effect of disinfectants in aqueous solution on the antibacterial activity is discussed for low molecular weight phosphonium salts with single and double long alkyl chains (carbon number 14). The proposed new concept can be applied to all phenomena reported previously in antibacterial activity of cationic biocides and this concept is very important from the viewpoint of molecular design of more active cationic biocides.

The functional limitations of tetraplegic hands for intermittent clean self-catheterisation

Since the introduction of intermittent self-catheterisation by Lapides et al, low pressure voiding methods have been adopted actively in our centre. A retrospective review of 47 patients with cervical spinal cord injury (CSCI) who performed independent (self) clean intermittent catheterisation (CIC) on discharge is presented. Their functional abilities were evaluated by both the Frankel and the Zancolli scales. Fourteen out of the 47 patients could manage independent CIC, 17 assisted CIC, nine tapped or voided voluntarily, two were discharged with a diaper, one with a suprapubic catheter, and four with an indwelling catheter. According to Frankel's classification, four patients were in A category, four in B, one in C and five in D among the group of complete CIC. C6A/C5B (right/left hand) by Zancolli's classification was the highest level of ability for all these 14 patients; and one patient (a 30-year-old male, Frankel B classification) could manage independent CIC with the aid of our special device. However, the practical limit of functional hands for independent CIC appeared to be about C6B1.

Effect of hypergravity on vestibular compensation in guinea pigs

The effect of hypergravity on vestibular compensation was studied in guinea pigs. Pharmacological labyrinthectomy was performed by injecting chloroform into the middle ear cavity under ether anesthesia. The guinea pigs were exposed to hypergravity on a centrifuge. The animals were divided into four groups: a group stimulated with 2G after labyrinthectomy of the right ear, a group stimulated with 2G after labyrinthectomy of the left ear to evaluate the influence of the centrifugal rotation, a group stimulated with acceleration and deceleration alone, and a control group which was maintained under similar conditions, but without centrifugation. Head deviation and nystagmus were recorded and analysed to assess the process of compensation at 1, 3, 5, 7 and 9 h after labyrinthectomy. The 2G-stimulated group showed faster compensation in head deviation than the control group. In this study, the hypergravity stimulation seemed to facilitate the compensation in head deviation.

Age-related reduction in bone matrix protein mRNA expression in rat bone tissues: application of histomorphometry to in situ hybridization

Age-related changes in the biological activity of osteoblastic cells have been studied extensively using histomorphometry, especially in relation to osteoporosis. Nevertheless, the changes occurring in the biological activity of individual osteoblastic cells are not sufficiently clarified by this technique. In the present study, age-related changes in the expression of bone matrix protein mRNAs in individual osteoblastic cells were analyzed in vivo by in situ hybridization using undecalcified bone sections. In the femurs of 8-week-old male rats, strong expression of type I collagen and osteocalcin mRNAs was detected in cuboidal osteoblasts on the bone formation surface. Osteopontin mRNA was detected in some of the mononuclear cells and osteoclasts on the bone resorption surface, and also in osteocytes. In the femurs of 60-week-old and 100-week-old male rats, expression of these bone matrix protein mRNAs was markedly decreased. Histomorphometrical analysis of 8-week-old and 60-week-old rats indicated that both the activity and number of osteoblasts expressing type I collagen mRNA, as well as the number of osteoclasts, were reduced in these tissues in older animals. These results indicate age-related reductions in both biological activity and numbers of osteoblasts.

Subpressor dose of angiotensin II increases susceptibility to the haemodynamic injury of blood pressure in Dahl salt-sensitive rats

OBJECTIVE

To investigate the effects of subpressor doses of angiotensin II (Ang II) on the progression of renal injuries in Dahl salt-sensitive (Dahl-S) rats with hypertension.

METHODS

Rats were fed a high-salt (4% NaCl) diet and given an Ang II infusion (10 or 50 ng/kg per min, subcutaneously) for 4 weeks.

RESULTS

The plasma Ang II concentration achieved in the high-dose Ang II infusion was lower than that in low-salt (0.3% NaCl) normotensive rats. The Ang II infusion did not affect systolic blood pressure, cardiac hypertrophy or weight of thoracic aorta. However, the high-dose Ang II infusion increased proteinuria by 58%, enhanced the urinary N-acetyl-beta-D-glucosaminase index by 77% and reduced the glomerular filtration rate by 37%. The impaired renal function was associated with a progression of glomerulosclerotic lesions. Neither tubular nor arterial lesions were exacerbated. The infusion did not influence prostacyclin production or urinary cyclic GMP excretion.

CONCLUSION

A subpressor dose of Ang II infusion impairs renal function with progression of glomerulosclerosis, and these alterations may be due to increased susceptibility of the glomerulus in Dahl-S rats to Ang II-induced injuries. Such a mechanism might underlie a predisposition to hypertension-induced organ damage seen in Dahl-S rats with salt-induced hypertension.

Synthesis and pharmacological activities of novel bicyclic thiazoline derivatives as hepatoprotective agents. I. 8-Ethoxycarbonyl-5,6-dihydrothiazolo[2,3-c][1,4]thiazine derivatives

A series of bicyclic thiazoline derivatives (4a-s) was synthesized and evaluated for hepatoprotective activity against galactosamine-induced and monoclonal antibody-induced acute liver injuries in rats. The structure-activity relationships were investigated. Among the compounds synthesized, ethyl 3-(N-methylcarbamoyl)-5,6-dihydrothiazolo[2,3-c][1,4]thiazin e-8- carboxylate (4p) exhibited remarkable hepatoprotective activity and lower toxicity. This compound suppressed galactosamine-induced hepatic injury at 100 mg/kg by gavage and further prevented monoclonal antibody-induced hepatic injury at 30 mg/kg by intraperitoneal injection, as evaluated by measuring changes in serum transaminase activities.

Endemic occurrence of glomerulonephritis associated with streptococcal impetigo

We report here a case of type 1 mesangiocapillary glomerulonephritis as well as a case of mesangial proliferative glomerulonephritis associated with streptococcal skin infection superimposed on atopic dermatitis. Both were endemic occurrences of postinfectious glomerulonephritis developed after repeated dirty-skin treatments for atopic dermatitis performed by unauthorized individuals under unsanitary conditions. Of 20 patients who were similarly treated and subsequently admitted to our hospital because of skin infection and fever, 8 (40%) showed urinary abnormalities. Four patients had renal dysfunction with acute nephritic onset. Almost all showed a decrease in CH50 values and an increase in levels of antistreptolysin O and IgE. In the 2 cases presented here, the disease eventually regressed in association with improvement of the skin infection. Although the occurrence of postinfectious glomerulonephritis has recently become uncommon, we must take care to note urinary abnormalities as early as possible in order to prevent the progression of glomerulonephritis.

Mice devoid of the glial fibrillary acidic protein develop normally and are susceptible to scrapie prions

Glial fibrillary acidic protein (GFAP) is an intermediate filament protein specifically expressed in astrocytes in the CNS. To examine the function of GFAP in vivo, the Gfap gene was disrupted by gene targeting in embryonic stem cells. Mice homozygous for the mutation were completely devoid of GFAP but exhibited normal development and showed no obvious anatomical abnormalities in the CNS. When inoculated with infectious scrapie prions, the mutant mice exhibited neuropathological changes typical of prion diseases. Infectious prions accumulated in brains of the mutant mice to a degree similar to that in control littermates. These results suggest that GFAP is not essential for the morphogenesis of the CNS or for astrocytic responses against neuronal injury. The results argue against the hypothesis that GFAP plays a crucial role in the pathogenesis of prion diseases.

Glycosaminoglycan components in duodenum with advancing age and in patients with progressive systemic sclerosis

The glycosaminoglycan (GAG) components in normal human duodenal tissue and in duodenal GAGs of patients with progressive systemic sclerosis (PSS) were characterized at the macromolecular level by electrophoresis combined with various GAG-specific digestion. High-performance liquid chromatographic assay quantified various unsaturated disaccharides derived from chondroitin sulfate and dermatan sulfate isomers (DS). The data obtained showed that on average, the total GAG content was 1.02 mg as uronic acid/g dry tissue weight, and the main GAGs were DS (33% of total GAGs), and heparan sulfates (HS, 27%), followed by hyaluronic acid (HA, 14%) and over-sulfated DS (10%), and small amounts of chondroitin, chondroitin-4- and -6-sulfates (C-4S and C-6S, totally 16%). With advancing age, the proportion of DS, HS and oversulfated DS increased, while HA, chondroitin and C-4S decreased. The composition of duodenal GAGs in PSS patients was similar to that in the aged: a higher proportion of DS isomers and HS and a lower proportion of HA and chondroitin. As the structure of sulfated GAGs differs with advancing age and in patients with PSS, GAGs may have a role in duodenal function and metabolism.

Fine structures of utricle of developing chick embryo exposed to 2G gravity

Utricular otoconia of the chick embryos incubated under continuous 2G load were examined under a scanning electron microscope. Morphological changes were confined to the process of otoconial formation and the otoconial size. Otoconial formation was remarkably delayed in the utricle of 2G centrifuged chick embryo. Giant otoconia, which sometimes amounted to over 100 microM in length, existed along the marginal zone of the utricular otolithic membrane. These results indicate that the 2G state influences the otoconical formation.

Isolation of porcine adenovirus as a candidate of 5th serotype

A strain of cytopathic virus, named strain TG/K79, was isolated from the brain of a newborn piglet, pure Hampshire breed, which died shortly after birth. The physicochemical property of virus was considered to be that of the family Adenoviridae. A significant difference between our isolated and 4 reference porcine adenoviruses was demonstrated by cross-seroneutralization test. Differences between TG/K79 and other porcine adenoviruses were also seen in electrophoretic patterns of viral DNA in agarose gel after digested by restriction endonucleases. Two SPF pigs, 2-month-old, experimentally infected via intranasal showed a fever and a hemorrhagic enteritis. A serological survey indicates that at least swine in the farm where the virus was isolated have been highly contaminated.

Delivery and cytotoxicity of RS-1541 in St-4 human gastric cancer cells in vitro by the low-density-lipoprotein pathway

RS-1541 is a 13-O-palmitoyl derivative of rhizoxin, an inhibitor of tubulin polymerization. RS-1541 has been shown to bind preferentially to plasma lipoproteins and to exhibit selective and sustained uptake by tumors in mice. To elucidate a mechanism of RS-1541 cytotoxicity, the cellular uptake and the cytotoxicity of a complex of RS-1541 with human low-density lipoprotein (RS-1541/LDL complex) were investigated in cultured St-4 human gastric cancer cells. Both the cellular uptake and the cytotoxicity of the RS-1541/LDL complex were greater in cells with higher LDL-receptor activities than in control cells. Excess amounts of LDL or 1 microM of monensin, a proton ionophore, significantly inhibited both the uptake and the cytotoxicity of the complex. Chloroquine, an inhibitor of lysosomal enzymes, decreased the intracellular level of rhizoxin liberated from RS-1541 and suppressed the cytotoxicity of the RS-1541/LDL complex. However, a detergent-aided solution of RS-1541 showed very low cellular uptake and cytotoxicity, irrespective of the LDL-receptor activities of these cells. These results demonstrate that the RS-1541/LDL complex is incorporated into the cells via the LDL receptor and that it manifests its cytotoxic activity after forming rhizoxin, the original antitumor agent, in the lysosomes.

A novel gut tetradecapeptide isolated from the earthworm, Eisenia foetida

A novel bioactive tetradecapeptide, GFKDGAADRISHGFamide, was isolated from the gut of the oligochaete annelid, Eisenia foetida, using the isolated anterior gut (crop-gizzard) as a bioassay system. A highly homologous peptide, GFRDGSADRISHGFamide, was also purified from the whole body of another species of earthworm, Pheretima vittata. These peptides were termed Eisenia tetradecapeptide (ETP) and Pheretima tetradecapeptide (PTP), respectively. Both the peptides showed a potent excitatory action on spontaneous contractions of the anterior gut with a threshold as low as 10(-10)-10(-9) M. These peptides were significantly homologous to molluscan tetradecapeptides and, to a lesser extent, to arthropodan tridecapeptides that have been reported to date. All these peptides seem to be evolutionally related to each other.

Bone morphogenetic protein-2 converts the differentiation pathway of C2C12 myoblasts into the osteoblast lineage

The implantation of bone morphogenetic protein (BMP) into muscular tissues induces ectopic bone formation at the site of implantation. To investigate the mechanism underlying this process, we examined whether recombinant bone morphogenetic protein-2 (BMP-2) converts the differentiation pathway of the clonal myoblastic cell line, C2C12, into that of osteoblast lineage. Incubating the cells with 300 ng/ml of BMP-2 for 6 d almost completely inhibited the formation of the multinucleated myotubes expressing troponin T and myosin heavy chain, and induced the appearance of numerous alkaline phosphatase (ALP)-positive cells. BMP-2 dose dependently induced ALP activity, parathyroid hormone (PTH)-dependent 3',5'-cAMP production, and osteocalcin production at concentrations above 100 ng/ml. The concentration of BMP-2 required to induce these osteoblastic phenotypes was the same as that required to almost completely inhibit myotube formation. Incubating primary muscle cells with 300 ng/ml of BMP-2 for 6 d also inhibited myotube formation, whereas induced ALP activity and osteocalcin production. Incubation with 300 ng/ml of BMP-2 suppressed the expression of mRNA for muscle creatine kinase within 6 h, whereas it induced mRNA expression for ALP, PTH/PTH-related protein (PTHrP) receptors, and osteocalcin within 24-48 h. BMP-2 completely inhibited the expression of myogenin mRNA by day 3. By day 3, BMP-2 also inhibited the expression of MyoD mRNA, but it was transiently stimulated 12 h after exposure to BMP-2. Expression of Id-1 mRNA was greatly stimulated by BMP-2. When C2C12 cells pretreated with BMP-2 for 6 d were transferred to a colony assay system in the absence of BMP-2, more than 84% of the colonies generated became troponin T-positive and ALP activity disappeared. TGF-beta 1 also inhibited myotube formation in C2C12 cells, and suppressed the expression of myogenin and MyoD mRNAs without inducing that of Id-1 mRNA. However, no osteoblastic phenotype was induced by TGF-beta 1 in C2C12 cells. TGF-beta 1 potentiated the inhibitory effect of BMP-2 on myotube formation, whereas TGF-beta 1 reduced ALP activity and osteocalcin production induced by BMP-2 in C2C12 cells. These results indicate that BMP-2 specifically converts the differentiation pathway of C2C12 myoblasts into that of osteoblast lineage cells, but that the conversion is not heritable.