Effects of iron chelates on the transferrin-free culture of rat dermal fibroblasts through active oxygen generation

Effects of nonchelating and chelating agents at 10 mM on the serum-free culture of rat dermal fibroblasts were investigated. A strong iron-chelating agent, iminodiacetic acid (IDA), and a weak one, dihydroxyethylglycine (DHEG), decreased iron permeation into preconfluent fibroblasts. A weak iron-chelating agent, glycylglycine (GG), a nonchelating agent, N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES), and human apotransferrin (10 micrograms/ml) increased the permeation with time. Iron may be essential for survival of fibroblasts because subconfluent fibroblasts exposed to 100 microM FeSO4 in combination with transferrin, HEPES, or GG significantly decreased to release lactate dehydrogenase into the medium. Superoxide dismutase and dimethyl sulfoxide blocked the enzyme release, suggesting that superoxide and hydroxyl radical induce cellular damage but hydrogen peroxide (H2O2) generated by superoxide dismutation does not. GG significantly reduced H2O2 cytotoxicity. DHEG acted as a potent promoter of the iron-stimulated cellular damage if ascorbate or H2O2 was added to the medium. FeSO4 and FeCl3 (50 to 100 microM) individually combined with IDA maximally promoted fibroblast proliferation. Ascorbate increased formation of thiobarbituric acid-reactive substances from deoxyribose in the medium supplemented with FeSO4 and either IDA or DHEG. Conversely, ascorbate decreased the formation in the medium with FeSO4 and with or without other agents. Fibroblast proliferation may thus be stimulated through the active oxygen generation mediated by a redox-cycling between Fe3+ and Fe2+, which are dissolved in the medium at a high concentration, rather than through delivery of iron into the cells.

Expansive laminoplasty for lumbar intradural lipoma

We evaluated the pre- and postoperative neurological state of 3 patients with lumbar intradural lipoma. Total resection of the lipoma in the cauda equina was impossible, and partial resection and expansive laminoplasty was carried out. Subsequent neural involvement may depend on the duration of symptoms rather than the extent of resection. Expansive laminoplasty is appropriate in these circumstances since decompression is combined with spinal stabilization.

Direct detection of hepatitis B virus gene integrated in the Alexander cell using fluorescence in situ polymerase chain reaction

Prolonged infection of hepatitis B virus (HBV) is reported to cause hepatocellular carcinoma (HCC) via liver cirrhosis. However, it is still unknown whether the HCC is induced by the HBV DNA integration or by inflammatory stimulation during the phase of liver cirrhosis. The aim of this study is to determine the intracellular or intranuclear distribution of HBV DNA with a highly sensitive assay. Here we directly detected the integration of HBV DNA by fluorescence in situ polymerase chain reaction (FISPCR). Since FISPCR products directly incorporate rhodamine-4-dUTP, the nucleus of Alexander cells integrated with HBV gene reacted with the HBV primers emits obvious fluorescence. The fluorescence values which were measured with an imaging analyzer show a significant difference between Alexander cells as compared to the controls. In conclusion, the target sequences of HBV were specifically amplified as fluorescent DNA after the present FISPCR procedure. This method could provide a novel and simple strategy for determining the quantitative role of viral DNA integration in oncogenesis.

Assessment of the carcinogenicity of stevioside in F344 rats

The carcinogenic potential of stevioside, a compound that is used as a sweetener for food and drink, was examined in F344 rats of both sexes. Stevioside was added to powdered diet at concentrations of 0 (control), 2.5 and 5%. The doses were selected on the basis of results from a 13-wk subchronic toxicity study and administered to groups of 50 male and 50 female rats ad lib. for 104 wk. All surviving rats were killed at wk 108. Body weight gains were slightly depressed in line with the dose of stevioside, in both sexes, and a significant decrease in the final survival rate was observed for the 5% treated males. Histopathologically, however, there was no significantly altered development of neoplastic or non-neoplastic lesions attributable to the stevioside treatment in any organ or tissue, except for a decreased incidence of mammary adenomas in females and a reduced severity of chronic nephropathy in males. It is concluded that stevioside is not carcinogenic in F344 rats under the experimental conditions described.

Risk indicators of low back pain among workers in Japan. Association of familial and physical factors with low back pain

STUDY DESIGN

A questionnaire was given to 3,042 Japanese workers at a factory in 1992. It surveyed age, gender, weight, height, job classification, and work environment, as well as the perceived causes, onset age, and characteristics of low back pain. Family history of low back pain among first-degree relatives and perception of physical condition also were assessed.

OBJECTIVES

To investigate the risk indicators of low back pain in Japanese workers with various kinds of job classifications in a manufacturing company.

SUMMARY OF BACKGROUND DATA

Risk indicators of low back pain in Japanese patients have not been fully investigated in previous studies.

METHODS

Prevalence rates and characteristics of low back pain were examined among 3,042 factory workers (2,517 men and 525 woman) with jobs with varying physical demands. In the analysis of risk indicators of low back pain, the odds ratios and 95% confidence intervals were computed. In addition, a multiple logistic analysis was performed to evaluate risk indicators of low back pain.

RESULTS

Point and lifetime prevalence of low back pain were correlated with the physical demands of the job. The perceived cause found to be most associated with low back pain were lifting in workers with jobs requiring moderate to heavy work and sports activity in sedentary workers. Family history of low back pain in parents, siblings, and children was a risk indicator of low back pain. The average age of the first attack of low back pain in workers with a family history of it in their parents was significantly younger than that in workers with no family history in a multiple logistic analysis in male workers, the physical work demands, age, and family history of low back pain in their parents were risk indicators; however, obesity was not a risk indicator. Physical and mental conditions of workers also were associated with low back pain.

CONCLUSIONS

The physical job demands show a clear association with the point and lifetime prevalence of low back pain, and improvements in work conditions may decrease low back symptoms among workers. It is likely that a family history of low back pain and physical and mental conditions of workers also should be considered in the management of low back pain.

Effects of dibutyryl cyclic adenosine monophosphate on nucleolar organizer regions and epidermal growth factor receptor of Dunn osteosarcoma cells

We investigated the characteristics of nucleolar organizer regions (NORs) and epidermal growth factor receptor (EGFR) on differentiated Dunn osteosarcoma in response to dibutyryl cyclic adenosine 3',5'-monophosphate (Bt2cAMP). In the presence of 3 mM Bt2cAMP, the mean number of NORs was significantly decreased in 24 hrs and 48 hrs compared with the untreated group. Also, EGFR affinity was decreased and the EGFR number was increased in response to the cellular differentiation by Bt2cAMP. The decrease in EGFR affinity might be considered as an indicator of differentiation or the mature state of the cells. Thus, the present study provides a new clue to support differentiation of osteosarcoma cells from the viewpoint of NORs findings and EGFR analysis as a differentiation marker.

Endometrial carcinoma in 45,X Turner's syndrome without hormone replacement therapy

An endometrial carcinoma developing in a patient with pure Turner's syndrome was described. The patient showed typical Turner's phenotype and analysis of karyotype revealed only 45,X. Secondary sexual development had been seen until age 20 and she had no history of hormone replacement therapy (HRT). The enlarged uterus and normal appearance of bilateral ovaries were detected at laparotomy. A well-differentiated adenocarcinoma of the endometrium and a graafian follicle of the left ovary were histologically confirmed. This seems to be the first report of the occurrence of endometrial carcinoma in possibly pure Turner's syndrome without HRT.

Postlaminectomy adhesion of the cauda equina. Changes of postoperative vascular permeability of the equina in rats

STUDY DESIGN

The authors evaluated the vascular permeability changes of the cauda equina after lumbar laminectomy in rats.

OBJECTIVES

To clarify the early vascular responses in postlaminectomy adhesive arachnoiditis.

SUMMARY OF BACKGROUND DATA

Laminectomy-induced cauda equina adhesion has been visualized by postoperative serial magnetic resonance imaging in humans. In laminectomized rats, fibrinous exudation was apparent among the adhered cauda equina. To date, there has been no report of substantial changes in vascular permeability in the cauda equina after lumbar laminectomy.

METHODS

Wistar rats laminectomized from L5-L6 were used for four studies; 1) Evans blue albumin tracer study; 2) horseradish peroxidase tracer study; 3) lanthanum tracer study; and 4) fluoroscein isothiocyanate-dextran (molecular weights: 20K, 70K, and 150K) tracer study. Untreated rats were used as controls.

RESULTS

1) In the laminectomized (L5-L6) area, the cauda equina tended to conglomerate from 3 hours after surgery; this was relatively resolved by 6 weeks. Extravascular leakage of Evans blue albumin in the cauda equina appeared at 3 hours after surgery and reached a plateau at 24 hours; it mostly disappeared by 6 weeks. At 24 hours after surgery, the extent of Evans blue albumin extravasation was seen in one or more levels adjacent to the laminectomized area. Evans blue albumin leakage and cauda equina adhesion started to appear in nearly a same phase after laminectomy, followed by a plateau of vascular permeability facilitating complete cauda equina adhesion by 24 hours after surgery. The restoration of Evans blue albumin leakage was noted 1 week after surgery, and tended to precede recovery of the cauda equina adhesion; 2) in the laminectomy group, Horseradish peroxidase penetrated from the lumen to the extracellular space beyond the basal laminae of the endothelial cells. Numerous horseradish peroxidase-labeled vesicles in the endothelial cells were found; 3) There was a significant increase in lanthanum distribution in the endothelial cytoplasm at the laminectomized levels. Lanthanum filled the interendothelial clefts beyond the tight junction, but did not penetrate through the perivascular basal laminae; 4) Fluoroscein isothiocyanate-dextran (20K, 70K, 150K) permeability increased in the laminectomy group, but there was no difference in extravasation of fluoroscein isothiocyanate-dextran, irrespective of the molecular weight.

CONCLUSION

Laminectomy consistently induced an increase in vascular permeability in the cauda equina, an increase of vesicular transport in the endothelial cell, and opening of the tight junction early after laminectomy, suggesting breakdown of the blood nerve barrier in the cauda equina. The accelerated permeability may enhance cauda equina adhesion.

Cartilage and subchondral bone interaction in osteoarthrosis of human knee joint: a histological and histomorphometric study

The present study has focused on the cartilage-bone interrelationships in the progression of osteoarthrosis in human knees. Eleven tibial condyles with osteoarthrosis were analyzed by histology and bonemorphometry. The data were evaluated according to the grade of joint cartilage degeneration in distinct areas of the tibial condyle. The bone morphometric data were also analyzed by the depth of subchondral bone. A parallel relationship between the bone volume/bone formation activity and the Mankin's grade of cartilage degeneration was observed in both medial and lateral condyles. In the lateral condyle, there was correlation among progression of cartilage degeneration and trabecular and osteoid thickness and bone formation activity. Osteoblasts and osteoclasts were most abundant in the external areas of the medial condyles. Bone resorption activity in the medial condyle was found only in the external and intermediate areas, but it was extremely low in all areas of the lateral condyle. The values of bone volume in relation to depth were highest in the superficial layer with a decrease as the depth increased in both condyles. The bone formation activity was high in the superficial layer of the lateral condyle, whereas in the medial condyle, it was high in the layer between 500 and 1,500 microns of depth. The bone volume and bone formation activity were higher in all layers of the medial condyle in comparison with the lateral condyle. The bone resorption activity was low in the superficial layer of the medial condyle as compared with deeper layers. These results suggested that the joint cartilage degeneration is influenced by the remodeling of the underlying subchondral bone.

Expansive lumbar laminoplasty for degenerative spinal stenosis in patients below 70 years of age

We reviewed the clinical and radiological results of patients with lumbar degenerative spinal stenosis who underwent expansive laminoplasty with a mean follow-up term of 5.6 years. Twenty-seven patients underwent open-door-type expansive lumbar laminoplasty, which has both decompression and stabilization effects. Clinical results were assessed based on the score system devised by the Japanese Orthopaedic Association (JOA score). The number and causes of repeat surgery were also evaluated. Radiological changes, such as degenerative scoliosis and spondylolisthesis, were evaluated at the operated levels and at levels L1-L5. There was marked recovery of clinical symptoms assessed by pre- and postoperative JOA score. Nearly 80% of patients obtained good or excellent results. Only one patient (4%) required additional surgery, which involved discectomy at the caudal level of the laminoplasty. Radiographic evaluation revealed that postoperative changes of spondylolisthesis and scoliosis were slight both in the expanded area and the L1-L5 levels. Range of motion of the disc space angle in the expanded area showed a significant decrease postoperatively. However, pre- and postoperative radiological changes showed no significant correlation with JOA score changes and repeat surgery. In conclusion, lumbar fusion after posterior decompression in active patients with spinal stenosis offers satisfactory clinical results concomitantly with a relatively small risk of repeat surgery.

Changes in serum creatine phosphokinase MM isoenzyme after lumbar spine surgery

STUDY DESIGN

Serum concentrations of creatine phosphokinase and its isoenzyme were measured serially in 47 patients who underwent lumbar surgery.

OBJECTIVE

To analyze the significance of postoperative creatine phosphokinase MM levels as indicators of muscle trauma after lumbar surgery.

SUMMARY OF BACKGROUND DATA

The authors of the present study previously have reported on iatrogenic back muscle injury in an animal model and in man. However, the relationship between the change of the creatine phosphokinase MM isoenzyme level and muscle injury after surgery has not been clarified.

METHODS

Peripheral venous blood samples were collected serially before surgery, just after surgery, and at 1, 3, 7, 14, and 21 days after surgery. The serum concentration of total creatine phosphokinase and its isoenzymes was measured by agarose gel electrophoresis. The serial postoperative change of the creatine phosphokinase MM isoenzyme concentration was evaluated with respect to age, gender, body weight, types and levels of surgery, and surgery time.

RESULTS

Creatine phosphokinase MM activity increased after surgery and reached a maximum value 1 day after surgery, followed by recovery to the normal value 1 week after surgery. The maximum concentration of creatine phosphokinase MM isoenzyme in posterior lumbar surgery was significantly higher than that in anterior surgery (P = 0.04). It was significantly higher in men than in women (P = 0.02). Serum concentration of creatine phosphokinase MM isoenzyme showed no significant correlation to the extent of muscle exposure and surgery time.

CONCLUSION

The time course of postoperative serum creatine phosphokinase MM isoenzyme activity is correlated with the histologic changes of the back muscles after surgery. The concentration of creatine phosphokinase MM isoenzyme in posterior lumbar surgery was significantly higher than that in anterior surgery. It was also significantly higher in men than in women.

Cloning and sequencing of a cDNA encoding alpha-glucosidase from sugar beet

A cDNA encoding sugar beet alpha-glucosidase was cloned from a library constructed from mRNA of suspension-cultured cells. The cDNA, 3056 bp in length, had an open reading frame encoding a polypeptide of 913 amino acid residues with a molecular mass of 102,078 Da, included only one of four regions which were conserved in the alpha-amylase family of enzymes. The deduced amino acid sequence from the analysis of the cDNA contained the sequences of the proteolysis peptides and the active site region peptide of sugar beet alpha-glucosidase. The primary structure indicated relatively high homology in the range of 28.2 to 54.3% to those for other alpha-glucosidases. The highest homology was found in barley alpha-glucosidase.

Involvement of calmodulin-dependent protein kinases-I and -IV in long-term potentiation

Multifunctional Ca2+/calmodulin-dependent protein kinases (CaMKs) are thought to be involved in the induction of long-term potentiation (LTP). In the present study, LTP was induced by theta burst stimulation in the Schaffer collateral area of the stratum radiatum in the hippocampal CA1 region of the rat hippocampus. LTP-induced and control hippocampal slices were studied by Western blot and immunohistochemical analyses using CaMK-I, -II and -IV antibodies. Increased amounts of all three CaMKs were found in LTP-induced hippocampal slices as indicated by Western blot as well as by the density of their immunoreactivity. Our data clearly shows that not only CaMK-II but also CaMK-I and -IV contribute to synaptic plasticity formed in LTP.

Increased oxysterol contents in diabetic rat hearts: their involvement in diabetic cardiomyopathy

BACKGROUND

Abnormal lipid metabolism associated with diabetes mellitus has been proposed to be involved in the pathogenesis of diabetic cardiomyopathy. Oxysterols, oxidation derivatives of cholesterol, are known to be highly cytotoxic.

OBJECTIVE

To monitor changes in myocardial oxysterols and to assess the effect of probucol, a lipid lowering agent, on myocardial lipids and oxysterols in diabetic rats.

METHODS AND RESULTS

Streptozotocin-induced diabetic rats were divided into two groups; one group was put on a standard diet, and the other a diet containing 1% (weight/weight) probucol for eight weeks. Two oxysterols, 7 beta-hydroxycholesterol and 7-ketocholesterol, were identified in myocardium by capillary gas chromatography. Both 7 beta-hydroxycholesterol and 7-ketocholesterol were significantly increased in diabetic rats (49.9 +/- 9.4 ng/mg dry weight versus 5.8 +/- 1.2 in controls, P < 0.05; and 5.3 +/- 1.2 ng/mg dry weight versus 1.7 +/- 0.1 in controls, P < 0.01, respectively). Probucol reduced not only plasma lipids but also myocardial lipids except for cholesterol and sphingomyelin fractions. However, probucol did not improve insulin deficiency, glucose metabolism or myocardial oxysterol contents.

CONCLUSIONS

This study demonstrated an increase in oxysterols in the myocardium of diabetic rats, suggesting that oxysterols may play a role in the development of diabetic cardiomyopathy. Probucol did not decrease the myocardial oxysterol content at the dose used in this study, suggesting that the increase in oxysterols may not be attributed to high circulating concentrations of lipids, but rather to disturbed myocardial metabolism due to insulin deficiency.

Significance of AgNOR counts for distinguishing carcinoma from adenoma and hyperplasia in parathyroid gland

Nucleolar organizer region proteins, which can be stained and visualized by an argyrophil technique (AgNORs), are markers of cell activities, such as DNA transcription and proliferation, and they are useful for differential diagnosis between benign and malignant tumors. We counted both AgNOR numbers in 25 parathyroid lesions (three carcinomas, 11 adenomas, 10 hyperplasias, and one hyperplasia with carcinoma) to determine if the AgNOR number could be useful as a diagnostic aid in parathyroid neoplasms and hyperplasias, because it is often difficult to histopathologically distinguish among these lesions. The AgNOR numbers were significantly higher in carcinomas (3.18 +/- 0.05) than in adenomas (1.67 +/- 0.30, P < .001) or hyperplasias (1.85 +/- 0.16, P < .001), but there was no significant difference between adenomas and hyperplasias. These results suggest that AgNORs may be useful as an adjunct to discriminating carcinomas from adenomas or hyperplasias in the parathyroid gland.

[Trial of radiation and cisplatin, carboplatin combination chemotherapy for advanced cancer (W-platinum chemoradiotherapy]

Cisplatin was reported to be an effective radiation sensitizing agent. The effect was also reported to depend on dose intensity. But the incidence of complication was demonstrated in the relationship with the dose escalation curve of anti-cancer agent. The major side effect of CDDP was occasionally serious, as in renal toxicity or bone marrow suppression. W-Platinum is the trial of concurrent chemoradiotherapy. Cisplatin and its derivative, Carboplatin, were selected as effective radiation sensitizing agents and to obtain high-dose intensity and additive cytotoxicities by interaction between the two drugs. Concomitant administration of two platinum anti-cancer agents has the advantage of reduction of side effects compared with administration of single anti-cancer agents to the same degree. The first case was a recurrence of epipharyngeal cancer after 3 courses of chemotherapy, including CDDP or CBDCA. This case was suspected to be cancer-resistant to CDDP. The second case was post-operative residual lung cancer. The pre-operative diagnosis was stage III A. A poor prognosis was expected. This case was disease-free and alive for 1 year after W-Platinum administration. The most frequent complication was bone marrow suppression. Patients were rescued from bone marrow suppression with administration of G-CSF. Renal toxicity could be suppressed with sufficient hydration.

Effects of ethane-1-hydroxy-1, 1 diphosphonate on Dunn osteosarcoma cells

We investigated the effects of ethane-1-hydroxy-1, 1 diphosphonate (EHDP) on Dunn osteosarcoma cells in vivo and in vitro. In in vivo study, an increase of tumor volume was significantly suppressed in the EHDP administered groups compared with the control group. Histologically, Dunn osteosarcoma cells' viability was maintained after EHDP administration. However, fatty degeneration of tumor tissue was suspected in two of eight mice in the 5.0 mg/kg EHDP administered group. In vitro study, EHDP inhibited DNA synthesis and induced morphological changes, such as pycnotic cells. These findings show that the growth of Dunn osteosarcoma cells is inhibited by EHDP.

Embryonic transplantation and ischemic memory deficit

Transient forebrain ischemia is associated with selective neuronal vulnerability and persistent memory deficit. This study compares functional outcome and morphological changes in rats subjected to post-ischemic CA1 or hilus/dentate gyrus region hippocampal fetal transplantation. Ischemia was produced by bilateral common carotid artery occlusion with hypotension. Fetal hippocampal neurons were transplanted into both sides of the CA1 or hilus/dentate gyrus region of the dorsal hippocampus, 1 week post-ischemia. Four weeks post transplantation, the rats underwent behavioral testing for 5 consecutive days using the water maze trial. All animals were perfusion fixed for morphological studies. Transplants in the CA1 region of the dorsal hippocampus were associated with memory and morphological recovery, while grafts placed into the hilus/dentate gyrus region of the dorsal hippocampus were not. Similarly, neurons transplanted in the CA1 region of the dorsal hippocampus were morphologically similar to CA1 pyramidal cell neurons and stained positive with calbindin D(28k). In contrast the grafts transplanted into the hilus/dentate gyrus region of the dorsal hippocampus were morphologically heterogeneous and staining with calbindin D(28k) was not as robust. Post-ischemic transplantation in the CA1 region of the dorsal hippocampus is effective in improving memory and morphological function.

Substitutions of alanine for cysteine at a reactive thiol site and for lysine at a pyridoxal phosphate binding site of 1-aminocyclopropane-1-carboxylate deaminase

1-Aminocyclopropane-1-carboxylate (ACC) deaminase catalyzes the cyclopropane ring fragmentation and deamination of ACC. Replacement of cysteine with alanine at a reactive thiol site, Cys-162, of ACC deaminase did not affect the enzyme activity, in spite of the previous result that modification of Cys-162 caused complete loss of the enzyme activity. Substitution of glycine or valine for the cysteine residue gave a higher Km for ACC without a significant change of the K0, indicating that changes of the amino acid side chain had structural effects on substrate binding. Replacement of lysine with alanine at the pyridoxal phosphate (PLP) binding site of the ACC deaminase caused a lower content of PLP and loss of detectable activity of ACC deamination. This mutant enzyme, K51A, showed absorption peaks at 330 nm and 405 nm. The peak at 405 nm was shifted to about 425 nm by the addition of ACC, D-, L-alanine, and D-, L-serine. The formation of aldimine complexes indicated by the spectral shift was reversible. It is suggested that lysine 51 affects the formation of holoenzyme and is important in catalysis.

Improved insulin sensitivity by bezafibrate in rats: relationship to fatty acid composition of skeletal-muscle triglycerides

We investigated the effect of the lipid-lowering agent, bezafibrate, on insulin sensitivity in a dietary model of insulin resistance. Male Sprague-Dawley rats were divided into four groups: control group, administered a standard diet; high-fructose group, given a 40% fructose diet; high-fructose plus lard group, given a 40% fructose diet with 7% lard; and bezafibrate group, given a 40% fructose plus 7% lard diet with 10 mg x kg-1 x day-1 of oral bezafibrate. Insulin action was assessed after 2 weeks with a steady-state plasma glucose (SSPG) level. The fatty acid (FA) composition of skeletal-muscle triglycerides was also determined. A higher SSPG level (20.9 +/- 0.9 vs. 16.5 +/- 1.1 mmol/l in the control group, P < 0.05) as well as a higher systolic blood pressure (120 +/- 2 vs. 101 +/- 2 mmHg, P < 0.01) was observed in the high-fructose plus lard group, but not in the high-fructose group. These changes were prevented by bezafibrate administration. The FA composition of skeletal-muscle triglycerides demonstrated a higher percentage of saturated and monounsaturated FAs (P < 0.01) and a lower percentage of polyunsaturated FAs (P <0.01) in the high-fructose plus lard group versus the control group. These changes were consistent with differences in the dietary intake of FAs. Bezafibrate virtually normalized the FA composition in the high-fructose plus lard group. The ratio of C20:4 to C20:3, an index of delta5 desaturase activity, was significantly higher in the bezafibrate group versus the high-fructose plus lard group (8.60 +/- 0.76 vs. 2.04 +/- 0.27, P < 0.01). In conclusion, the dietary FA composition was closely related to insulin resistance in rats fed 40% fructose. Bezafibrate increased delta5 desaturase activity. Such action may contribute to the improvement of insulin sensitivity.

Ampelopsis brevipedunculata (Vitaceae) extract stimulates collagen synthesis through superoxide generation in the serum-free cultures of rat dermal fibroblasts and Ito cells

We describe the effects of an ethanol-extracted fraction of berries of Ampelopsis brevipedunculata (Maxim.) Trautv. (Vitaceae), a plant used in folk medicine to treat liver disease, on the synthesis of non-collagenous proteins and collagen by rat collagen-producible cells such as dermal fibroblasts and liver non-parenchymal Ito cells. The generation of superoxide and hydroxyl radical was assessed by measuring the reduction of cytochrome c and the formation of thiobarbituric acid-reactive substances from deoxyribose, respectively. The synthesis of non-collagenous proteins and collagen as evaluated by measuring the extent of [3H]tryptophan incorporation into a total protein fraction of culture products and the [3H]proline-incorporating rate into a collagenase-digestible protein fraction, respectively. Both types of cells promptly synthesized only collagen in response to a dialyzable fraction of the extract. Major activity to generate oxygen free radicals accumulated in the dialyzable fraction whereas activity to decrease ferrous iron-mediated generation of the radicals accumulated in an undialyzable fraction of the extract. Stimulation of collagen synthesis was caused by superoxide because addition of superoxide dismutase but not pyruvate, an antioxidant of hydrogen peroxide, or dimethyl sulfoxide, an antioxidant of the hydroxyl radical, abrogated the stimulatory effect. The extract may arrest the progress of liver injury mediated by oxygen free radicals generated in the presence of ferrous iron.

Identification of essential ionizable groups in active site of Aspergillus niger alpha-glucosidase

A kinetic study was done to identify the ionizable groups in the active site of Aspergillus niger alpha-glucosidase (ANGase). From dependence of V and Km values on pH, we obtained the ionization constants of essential ionizable groups 1 and 2 of free enzyme; pKe1 = 3.2 and pKe2 = 6.4. When the dielectric constant of the reaction mixture was decreased, the pKe1 and pKe2 were shifted to higher values. The ionization heats (delta H's) of ionizable groups 1 and 2 were measured to be -0.4 kcal/mol and 0 kcal/mol, respectively. The water-soluble carbodiimide (WSC), a specific reagent for carboxyl groups, inactivated the enzyme activity completely, and maltose as substrate decreased the inactivation. The WSC did not modify the free Cys. These findings suggest that the essential ionizable groups of ANGase are two kinds of carboxyl groups: one is a charged type (-COO-, ionizable group 1), and the other is a protonated type (-COOH, ionizable group 2).

Effects of Ampelopsis brevipedunculata (Vitaceae) extract on hepatic M cell culture: function in collagen biosynthesis

A spirits-extracted fraction of berries of Ampelopsis brevipedunculata (Maxim.) Trautv. (Vitaceae) is used in Japanese folk medicine to treat liver disease. Since such an extract has been shown to inhibit formation of collagen fibers by rat hepatic M cells, it was felt that the extract acts as an inhibitor of hepatic fibrosis. Amino acid analysis of fibrous substances developing on M cell layers and of a cell lysate fraction indicated that an A. brevipedunculata extract inhibited collagen formation. Biosynthesis of non-collagenous proteins and collagen was evaluated by measuring the extent of [3H]tryptophan incorporation into a protein fraction and the rate of [3H]proline incorporation into a collagenase-digestible fraction, respectively. In contrast to the results of the analysis of the fibrous substances, the A. brevipedunculata extract failed to decrease synthesis of non-collagenous proteins and collagen unless cell proliferation was inhibited. There was no detectable level of collagenolytic activity in the M cell culture with the A. brevipedunculata extract. The decrease in accumulation of collagen, therefore, appeared to be a consequence of the proliferation-inhibitory effect of the A. brevipedunculata extract. Such inhibitory activity was found in a macromolecular fraction that contained abundant sugars but lacked proteins.

Reproductive status in GTD treated with etoposide

OBJECTIVE

To investigate the mechanism and degree of ovarian dysfunction in gestational trophoblastic disease (GTD) patients treated with etoposide alone.

STUDY DESIGN

Forty-seven patients with low-risk GTD were treated with etoposide alone, and pituitary-ovarian function was evaluated by measuring basal serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol and progesterone and by recording basal body temperature. Moreover, the responses of LH and FSH to the administration of LH-releasing hormone (LHRH) and the responses of prolactin to thyrotropin-releasing hormone (TRH) were analyzed after the completion of etoposide treatment.

RESULTS

Increased basal LH and FSH levels were found in approximately 50% of patients, especially those over 40 years old. Although the LH and FSH responses to LHRH were exaggerated in patients with high basal FSH levels, the prolactin responses to TRH were normal. Ovulation resumed within 121 days after the cessation of chemotherapy in women under 39 years. However, five of nine patients over 40 years remained anovulatory during the follow-up period.

CONCLUSION

Ovarian function was impaired in approximately 50% of patients treated with etoposide at the time of LHRH study, though pituitary function was preserved. This complication is age related but not related to the amount of etoposide exposure. Therefore, we must consider the possibility of permanent anovulation when we treat patients 40 years old and older.