Histologic study of the femoral growth plate in beagle dogs

The femora of normal-growing beagle dogs were examined histologically at 6 and 12 mo of age to clarify the morphologic changes occurring in the femoral growth plate as background data for studies of chondrosseous toxicology. Enchondral ossification was active at 6 mo of age, and the growth plate disappeared at 12 mo. The growth plate showed degradation of the matrix and destructive lesions at 6 mo of age. Degradation of the matrix was observed between the chondrocytic columns accompanied by degeneration and disappearance of chondrocytes. Destructive changes were seen in the epiphyseal hyaline cartilage and proliferating and hypertrophic zones, resulting in disarrangement of the chondrocytic columns. Furthermore, abnormal chondrocytic proliferation of the epiphyseal hyaline cartilage zone and cleftlike fractures between the growth plate and cortex were frequently present. No abnormalities were detected in the articular cartilage at 6 and 12 mo of age.

Early detection of hepatocellular carcinoma associated with cirrhosis by combined assay of des-gamma-carboxy prothrombin and alpha-fetoprotein: a prospective study

BACKGROUND/AIMS

To evaluate the usefulness of des-gamma-carboxy prothrombin (DCP) assay in a group of high risk for hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Plasma DCP and serum-alpha-fetoprotein (AFP) concentrations were prospectively measured in 137 patients with liver cirrhosis (LC).

RESULTS

During the mean observation period of 3.4 years, HCC developed in 35 patients (25.5%; yearly rate 7.5%), of whom 16 (45.7%) had a small tumor < or = 2 cm in diameter. Eight patients (22.9%) had significantly elevated DCP at the time of HCC detection. However, all these tumors measured > 2 cm and were multiple or diffuse type. In cases with a tumor diameter < or = 2 cm HCC was diagnosed by imaging and elevated AFP concentrations. In contrast, elevated DCP frequently leads to the detection of tumors > 2 cm or those of diffuse type, which are difficult to recognize with imaging.

CONCLUSIONS

Thus, although DCP alone is not sensitive enough to detect early small liver cancers, the use of both markers and imaging in the follow-up of patients with LC might be beneficial.

The small GTP-binding protein, rho p21, is involved in bone resorption by regulating cytoskeletal organization in osteoclasts

Rho protein (rho p21), a p21ras-related small guanine nucleotide binding protein, regulates cytoskeletal organization in a number of different types of cells. Evidence has indicated that Clostridium botulinum-derived ADP-ribosyltransferase (C3 exoenzyme) specifically ADP-ribosylates rho p21 at Asn41 and renders it functionally inactive. In this study, we examined the involvement of rho p21 in osteoclastic bone resorption using the C3 exoenzyme. When osteoclast-like multinucleated cells obtained from cocultures of mouse osteoblastic cells and bone marrow cells were placed on dentine slices, they formed ringed structures of podosomes containing F-actin (corresponding to the clear zone) within 8 hours. Many resorption pits were formed on dentine slices after culture for 24 hours. The C3 exoenzyme at 0.15-10 micrograms/ml added to the culture medium disrupted the ringed structure of podosomes in osteoclast-like cells in a dose-dependent manner. Correspondingly, pit formation by osteoclast-like cells on dentine slices was dose-dependently inhibited also by adding the C3 exoenzyme. Microinjection of the C3 exoenzyme into osteoclast-like cells placed on culture dishes completely disrupted the ringed podosome structure within 20 minutes. The amount of the rho p21 which was ADP-ribosylated by the C3 exoenzyme in vitro was much greater in purified osteoclast-like cells than in osteoblastic cells. Prior exposure of the purified osteoclast-like cell preparation to the C3 exoenzyme in vivo markedly decreased the amount of unribosylated rho p21. This indicated that the C3 exoenzyme incorporated into osteoclast-like cells effectively ADP-ribosylates rho p21 in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Infrequent replication errors at microsatellite loci in tumors of patients with multiple primary cancers of the esophagus and various other tissues

Patients with esophageal cancer are at high risk of developing other primary tumors, especially squamous cell carcinoma in the head and neck. Heavy smoking and excessive consumption of alcohol are considered to be crucial environmental risk-factors for development of these multiple primary cancers. To investigate whether any genetic background, such as defects in the DNA-mismatch repair system, may influence the development of these multiple primary tumors, we examined replication errors (RER) at six microsatellite loci in DNAs of 46 tumors from 33 patients who had developed primary cancers in various tissues in addition to the esophagus. RER(+) (RER-positive) phenotype was observed in three tumors in two patients of the 33 patients examined. Our results suggested that development of multiple primary tumors in these patients would not be affected by an abnormality in the DNA repair system(s) detected as the RER phenotype. However, it is noteworthy that a single patient who developed multiple cancers revealed RER(+) phenotypes at multiple microsatellite loci in both tumors, indicating that a defect in the DNA repair gene(s) may have played an important role in the development of the tumors in this patient.

Characterization of the internal motions of Escherichia coli ribonuclease HI by a combination of 15N-NMR relaxation analysis and molecular dynamics simulation: examination of dynamic models

The backbone dynamics of Escherichia coli ribonuclease HI (RNase HI) in the picosecond to nanosecond time scale were characterized by a combination of measurements of 15N-NMR relaxation (T1, T2, and NOE), analyzed by a model-free approach, and molecular dynamics (MD) simulation in water. The MD simulations in water were carried out with long-range Coulomb interactions to avoid the artificial fluctuation caused by the cutoff approximation. The model-free analysis of the 15N-NMR relaxation indicated that RNase HI has a rotational correlation time of 10.9 ns at 27 degrees C. The generalized order parameter (S2) for the internal motions varied from 0.15 to 1.0, with an average value of 0.85, which is much larger than that of the RNase H domain of HIV-1 reverse transcriptase (0.78). Large internal motions (small order parameters) were observed in the N-terminal region (Leu2-Lys3), the loop between beta-strands A and B (Cys13-Gly15), the turn between alpha-helix I and beta-strand D (Glu61, His62), the loop between beta-strand D and alpha-helix II (Asp70-Tyr71), the loop between alpha-helices III and IV (Ala93-Lys96), the loop between beta-strand E and alpha-helix V (Gly123-His127), and the C-terminal region (Gln152-Val155). The effective correlation time observed in these regions varied from 0.45 ns (Glu61, Lys96) to 2.2 ns (Leu14). The order parameters calculated from the MD agreed well with those from the NMR experiment, with a few exceptions. The distributions of most of the backbone N-H vectors obtained by MD are approximately consistent with the diffusion-in-a-cone model. These distributions, however, were elliptic, with a long axis perpendicular to the plane defined by the N-H and N-C alpha vectors. Distributions supporting the axial fluctuation model or the jump-between-two-cones model were also observed in the MD simulation.

Antiallergic dimeric prenylbenzoquinones from Ehretia microphylla

The ethyl acetate-soluble portion of the MeOH extract of Ehretia microphylla showed inhibitory activity on exocytosis in antigen-stimulated rat basophils. The bioassay-guided separation of this fraction afforded five biologically active compounds. By means of chemical and spectroscopic methods, the structures of these compounds, which include microphyllone, a unique dimeric prenylbenzoquinone, and its congeners, were elucidated.

Synthesis of 4-(phenylamino)quinoline-3-carboxamides as a novel class of gastric H+/K+-ATPase inhibitors

In search for inhibitors of gastric H+/K+-ATPase, 4-(phenylamino)quinoline-3-carboxamides were synthesized and evaluated for antisecretory activity against histamine-induced gastric acid secretion in rats. These compounds were synthesized by condensation of aniline derivatives with N-substituted 4-chloroquinoline-3-carboxamides, which were obtained from treatment of 4(1H)-quinolinone-3-carboxylic acid with thionyl chloride. Most of the compounds inhibited histamine-induced gastric acid secretion in rats. Among them, N-allyl-4-(2-ethylphenylamino)quinoline-3-carboxamide (4h) was the most potent inhibitor and had the best profile as a candidate antiulcer agent. This compound showed reversible, K+-competitive gastric H+/K+-ATPase inhibitory activity.

Spirostanol glycosides from Peliosanthes sinica

Three new spirostanol glycosides, peliosanthosides A--C, were isolated from the whole plants of Peliosanthes sinica, along with two known ones. Their structures were elucidated by means of chemical and spectral evidence.

[Evaluation of photon-counting X-ray radiography for the detection of pulmonary nodule: a preliminary report on experimental and clinical studies]

To evaluate the utility of photon counting X-ray radiography (quantum radiography: QR) for the detection of pulmonary nodules, experimental and clinical studies were performed in comparison with conventional X-ray (CXR). In the experimental study, spatial resolution was analyzed by using the micro-chart method. The simulated nodule detection study was performed by using a chest phantom. The results were evaluated by means of ROC analysis. In the clinical study, both images of CXR and QR were evaluated in a case of metastatic lung tumor. In the experimental study, the spatial resolution of QR was 200 microns. QR was superior to CXR in detecting simulated nodules in all areas. In clinical cases, QR was superior to CXR in depicting not only normal structures but also retrocardiac and retrodiaphragmatic pulmonary nodules.

Solution structure of a human calcitonin analog elucidated by NMR and distance geometry calculations

Three-dimensional structure of a human calcitonin analog (abbreviated as hCTa) in which the amino acids of the wild type are replaced at position 12, 16 and 19 by leucine residues and further at position 22 by a tyrosine residue was studied in TFE solution by 1H-NMR and distance geometry calculations. This analog has a 15-20 times activity as compared with the wild type. The amino acid replacements resulted in formation of an amphiphilic alpha-helix in the region between the residues 4-20. The overall three-dimensional structure is similar to that of the wild type. The conformational feature of hCTa with a hydrophobic face composed with a Met and four Leu residues may be related to its higher hypocalcemic potency.

Indirect portography enhanced by nicardipine versus prostaglandin E1

PURPOSE

To compare nicardipine (NCR) and prostaglandin E1 (PGE1) for portal venous contrast enhancement on indirect portography in a retrospective study.

METHODS

One milligram of NCR, a calcium antagonist, was injected into the superior mesenteric artery just prior to portography in 18 patients who had undergone otherwise identical portography using 20 micrograms PGE1 36-279 (mean 133) days before. All 18 patients had liver tumors and showed no changes in portal vein status in the interim.

RESULTS

Using conventional film/screen angiography, NCR provided equally good portograms as PGE1 with respect to image density and image contrast. Systemic effects on blood pressure and heart rate were minimal and no other side effects were observed with NCR.

CONCLUSION

NCR is an inexpensive drug and is expected to provide well-contrasted, indirect portograms on conventional film/screen angiography.

Transient adenosine infusion before ischemia and reperfusion protects against metabolic damage in pig hearts

We investigated whether transient adenosine (Ado) infusion before ischemia had the same effect on myocardial metabolism and function as ischemic preconditioning (IP). The control (C) group underwent 15 min of coronary artery occlusion followed by 120 min of reperfusion. The Ado group received a 15-min infusion of Ado (200 micrograms.kg-1.min-1) into the left atrium starting 20 min before ischemia. IP was elicited by two cycles of 5-min ischemia and 5-min reperfusion. In the area at risk, tissue levels of ATP, creatine phosphate (CP), and intracellular pH (pHi) were serially measured by 31P-nuclear magnetic resonance spectroscopy in 10 pigs from each group, and percent segment shortening (%SS) was measured in 7 pigs from each group. ATP and pHi were preserved after 15 min of ischemia in both Ado and IP groups [ATP = 64 +/- 7, 76 +/- 6, and 74 +/- 9% of baseline; pHi = 6.35 +/- 0.19, 6.54 +/- 0.11, and 6.64 +/- 0.11 in C, Ado, and IP groups, respectively (P < 0.05, Ado and IP vs. C)]. During reperfusion, ATP was restored progressively in both groups [71 +/- 7, 90 +/- 8, and 91 +/- 9% of baseline at 120 min of reperfusion in C, Ado, and IP groups, respectively (P < 0.05, Ado and IP vs. C)]. However, in contrast to the IP group, CP was not preserved during 15-min ischemia nor did it show persistent overshoot during reperfusion in the Ado group. There were no significant differences in %SS during ischemia and reperfusion among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between gastroprotective effect of locally acting antiulcer agent ecabet sodium and its binding to gastric mucosa in rats. Comparison with sucralfate

The present study was designed to examine the relationship between the gastroprotective efficacy of the locally acting antiulcer drug ecabet sodium (ecabet) against ethanol-induced gastric lesions and the amount of the drug bound to the mucosa in comparison with sucralfate in rats. Oral administration of ecabet (25-100 mg/kg) and sucralfate (25-400 mg/kg) dose dependently prevented the formation of ethanol-induced gastric lesions, and dose dependently increased the amount of each drug bound to the gastric mucosa. Pretreatment with the antisecretory agent cimetidine (200 mg/kg, per os) significantly reduced the gastroprotective effect of sucralfate in proportion to a decrease in its binding to the mucosa. The same pretreatment tended to reduce both gastroprotection by ecabet and its binding to the mucosa. In an in vitro study using an everted stomach sac, the binding of sucralfate to the mucosa was more markedly decreased than that of ecabet on increasing the pH. These findings indicate that ecabet and sucralfate protect the gastric mucosa against ethanol in proportion to the amount of each drug bound to the gastric mucosa and that the binding of these drugs to the mucosa is under the influence of intraluminal pH. However, the gastroprotective effect of ecabet seems to be less dependent on intraluminal acidity than that of sucralfate.

Effect of a lipid-lowering agent or a high-cholesterol diet on focal glomerulosclerosis in hyperlipidemic rats

Hyperlipidemic rats given a diet supplemented with 1% probucol (4,4'-isopropylidenedithiobis [2,6-di-tert-butylphenol]) or 4% cholesterol with 1% cholic acid from 4 to 20 weeks of age were evaluated for the effect of a lipid-lowering agent or a high-cholesterol diet on focal glomerulosclerosis. Although mean cholesterol and phospholipid concentrations in hyperlipidemic rats given probucol were lower than those in control hyperlipidemic rats, there was no difference in urinary protein content or renal histologic findings when the two groups were compared. Mean cholesterol, phospholipid, urea nitrogen, and creatinine concentrations in hyperlipidemic rats given a high-cholesterol diet were greater than those in hyperlipidemic rats given a normal diet, and the glomerular sclerotic lesions became more severe.

Irradiation with ultraviolet light in the presence of vanadate increases Ca2+ permeability of the sarcoplasmic reticulum membrane via Ca(2+)-ATPase

The sarcoplasmic reticulum (SR) of rabbit skeletal muscle was irradiated with ultraviolet light (UV) in the presence of vanadate plus 2 mM EGTA, 10 mM MgCl2, 20% DMSO, and 50 mM PIPES (pH 6.5) at room temperature. In the presence of 100 microM vanadate, the Ca(2+)-uptake activity of SR rapidly decreased and was almost lost in 20 min. The activity was inhibited as a function of vanadate concentration with an apparent Ki of about 20 microM. On the other hand, Ca(2+)-dependent ATP hydrolytic activity as well as phosphoenzyme (EP) formation activity decreased very slowly, and more than 50% of these activities remained 20 min after initiation of the vanadate-UV treatment. Half inhibition of these activities required about 100 microM vanadate. The loss of the relationship between Ca(2+)-uptake and ATPase reaction was found to be mainly caused by an increase in the Ca2+ permeability of the SR membrane, which was raised by increasing the vanadate concentration or UV irradiation time in a manner similar to that observed for the Ca2+ uptake. No rise in Ca2+ permeability occurred in liposomes reconstituted from SR lipid when they were irradiated with UV in the presence of 100 microM vanadate. When the vanadate-UV-treated SR was allowed to react with fluoral-P (4-amino-3-penten-2-one), an indicator of aldehyde, and the membrane proteins were separated by HPLC in the presence of SDS, the fluorescent probe was found to be closely associated with the Ca(2+)-ATPase fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of remarkable response of colon cancer with multiple liver and bone metastasis treated with tegafur and cisplatin]

A 47-year-old man with ascending colon cancer with multiple liver metastases and bone metastasis (VII thoracic vertebra) showed a remarkable response to the combination therapy of tegafur and cisplatin. Tegafur (1,200 mg/day) was administered through continuous intravenous infusion mixed with IVH, and cisplatin was given every two weeks at a dose of 100 mg. The total dose of tegafur was 39.6g and that of cisplatin was 300mg. After therapy, primary and metastatic lesions were remarkably reduced according to various imaging techniques, and the serum CEA level of 34ng/ml at diagnosis decreased 3.7 ng/ml. Various tumor-related symptoms were improved. Drug toxicity caused slight nausea and leucopenia. Right hemicolectomy with R2 lymph node dissection was performed after chemotherapy. Histologically, primary lesion and regional lymph nodes showed diffuse fibrosis and necrosis, and only a few cancer cells remained some vessels. These results suggested that the combination chemotherapy of tegafur and cisplatin is useful for the treatment of colon cancer.

Characterization of blasts from a patient with eosinophilic blast crisis of chronic myelogenous leukaemia

We investigated the biological characteristics of 'eosinophilic' leukaemic blasts from a patient with eosinophilic blast crisis of chronic myelogenous leukaemia (CML). Southern blot analysis of the bcr gene demonstrated the identical single rearranged band in both the leukaemic blasts and mature eosinophils. IL-3, IL-5 and GM-CSF significantly enhanced proliferation and differentiation of these leukaemic blasts, and only eosinophils were generated from in vitro cultures. Those eosinophils expressed the B3A2 chimaeric messenger RNA seen in the leukaemic blasts. These observations indicate that eosinophil progenitors may be involved in the development of eosinophilic blast crisis of CML and that IL-3, IL-5 and GM-CSF act on the leukaemic eosinophil progenitors.

Hydroxyl radical scavenging by rebamipide and related compounds: electron paramagnetic resonance study

We studied the scavenging activity of rebamipide, a novel antipeptic ulcer agent, and seven related compounds against hydroxyl radicals using the electron paramagnetic resonance (EPR) spin trapping technique. 5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) was used as a spin trapping agent. We estimated the second order rate constant for the reaction between the agents tested and hydroxyl radical at pH 7.8 by kinetic competition studies. All compounds tested scavenged the hydroxyl radicals with a certain relationship between concentration and scavenging efficacy. A structure-scavenging activity relationship was derived from the kinetic evidence available on the formation and inhibition of the DMPO spin adduct EPR signal of hydroxyl radicals (DMPO-OH). Important determinants for scavenging hydroxyl radicals were the 3,4-double bond of the quinolinone ring in conjunction with a 2-oxo function and the carbonyl portion of the amido group in conjunction with a para-chlorobenzoyl function.

Characterization of region Ic in site I on human serum albumin. Microenvironmental analysis using fluorescence spectroscopy

Characteristics of region Ic among at least three overlapping binding regions (regions Ia, Ib and Ic) in site I on human serum albumin (HSA) were analysed using n-alkyl p-aminobenzoates (n-alkyl p-ABEs), all of which are specific fluorescent probes for region Ic. In the interaction processes between n-alkyl p-ABEs and HSA, hydrophobic interaction, van der Waals interaction and local structural changes in region Ic were found to be involved based on the results obtained by analyses of the fluorescence spectra, structure-activity relationships and thermodynamic parameters. In addition, comparison of the fluorescence spectra of n-alkyl p-ABEs in HSA and detergents indicated that the possibility of a hydrophobic region Ic around which an amino acid with cationic charge locates could not be denied because of the similarity of fluorescence spectra between n-alkyl p-ABEs in HSA and in neutral and cationic detergents. The deviation of n-alkyl p-ABEs with long alkyl chains (C9-C12) in the relationships between association constants and physicochemical properties of a series of n-alkyl p-ABEs (C1-C12) suggested that region Ic possess an optimal depth. A conformational change of HSA with increasing pH (pH 6-9) generated an increase in hydrophobicity and adaptability of the binding region and made interaction easy, with an increase in adaptability of the binding region Ic; consequently, it enhanced the binding of n-alkyl p-ABEs to HSA.

Oleanane and ursane glycosides from Schefflera octophylla

Twelve triterpene glycosides were isolated from the bark of Schefflera octophylla of Vietnamese origin. Three of them were identified as asiaticoside, cauloside D and 3 alpha-hydroxyurs-12-ene-23,28-dioic acid 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside. The structures of nine new glycosides were elucidated by chemical and spectroscopic evidence. Including the known compounds, the 12 glycosides consisted of six pairs of corresponding ursene and oleanene glycosides and all of them had the same triose moiety at the C-28 position. The names scheffurosides A-F and scheffoleosides B-F were proposed for corresponding pairs of ursene and oleanene glycosides, respectively.

Interaction of benzothiadiazides with human serum albumin studied by dialysis and spectroscopic methods

The interaction of a series of benzothiadiazides with human serum albumin (HSA) was investigated by equilibrium dialysis (ED) and spectroscopic methods including circular dichroism (CD). The primary binding site of benzothiadiazides was designated site II, the diazepam site on the HSA molecule, as indicated by displacement experiments using different site-selective probes. Tyrosine and lysine amino acid residues were probably involved in the binding site of these compounds to HSA. Both electrostatic and hydrophobic interactions were found to play a role in the binding of these compounds to HSA. Among the compounds tested, chlorothiazide had the highest affinity (K1 = 5.5 x 10(4) M-1, K2 = 5.8 x 10(3) M-1). The primary binding affinity of the compounds for HSA was of the order: chlorothiazide > cyclopenthiazide > polythiazide > ethiazide > trichlormethiazide = methyclothiazde > hydrochlorothiazide. Binding was insensitive to the N-B transition of HSA. The binding site is proposed to consist of a cationic site on the surface of the HSA molecular with a hydrophobic crevice to accommodate the aromatic ring of the compounds. Positions 3 and 7 of the benzothiadiazide molecule is thought to affect the binding affinity to HSA.

[Single-dose toxicity studies of tazobactam/piperacillin and tazobactam]

Tazobactam (TAZ) is a newly developed beta-lactamase inhibitor. Tazobactam/Piperacillin (TAZ/PIPC) is a formulation consisting of TAZ and PIPC in a ratio of 1:4. Singe-dose toxicity studies in TAZ/PIPC and TAZ were carried out using mice and rats of both sexes and male dogs. The results were as follows. 1. A common clinical sign in mice and rats administered TAZ/PIPC or TAZ by all routes was soft stool. Other signs in mice and rats included a decrease in spontaneous motor activity and/or a decreased respiratory rate for the intraperitoneal (i.p.), subcutaneous (s.c.) or intravenous (i.v.) route. The animals administered by the i.v. route showed tremor for mice and clonic convulsion for rats before death. Hyperemia, hemorrhage or edema of the lung, and hemorrhage of the digestive tract were observed in these animals at necropsy. An enlargement of the spleen was seen in some of the surviving animals treated with TAZ/PIPC. 2. In dogs, TAZ/PIPC caused vomiting, and TAZ caused vomiting, respiratory abnormality, soft stool and diarrhea by the intravenous (i.v.) administration. 3. TAZ/PIPC or TAZ caused clinical signs such as the loss of hair at the injection site for the s.c. route, and necrosis of the tail for the i.v. route in mice and rats, also caused limping of the injected anterior limb in dogs. Necrosis and hemorrhage at the injection site, and peritonitis by the i.p. injection were observed at necropsy. These findings were due to the irritation of TAZ/PIPC or TAZ.(ABSTRACT TRUNCATED AT 250 WORDS)