Tubulin protofilaments and kinesin-dependent motility.

Microtubules are built of tubulin subunits assembled into hollow cylinders which consist of parallel protofilaments. Thus, motor molecules interacting with a microtubule could do so either with one or several tubulin subunits. This makes it difficult to determine the structural requirements for the interaction. One way to approach the problem is to alter the surface lattice. This can be done in several ways. Proto-filaments can be exposed on their inside (C-tubules or "sheets"), they can be made antiparallel (zinc sheets), or they can be rolled up (duplex tubules). We have exploited this polymorphism to study how the motor protein kinesin attached to a glass surface interacts and moves the various tubulin assemblies. Microtubules glide over the surface along straight paths and with uniform velocities. In the case of C-tubules, approximately 40% glide similarly to microtubules, but a major fraction do not glide at all. This indicates (a) that a full cylindrical closure is not necessary for movement, and (b) that the inside surface of microtubules does not support gliding. With zinc sheets, up to 70% of the polymers move, but the movement is discontinuous, has a reduced speed, and follows along a curved path. Since zinc sheets have protofilaments alternating in orientation and polarity, this result suggests that in principle a single protofilament can produce movement, even when its neighbors cannot. Duplex microtubules do not move because they are covered with protofilaments coiled inside out, thus preventing the interaction with kinesin. The data can be explained by assuming that the outside of one protofilament represents the minimal track for kinesin, but smooth gliding requires several parallel protofilaments. Finally, we followed the motion of kinesin-coated microbeads on sea-urchin sperm flagella, from the flagellar outer doublet microtubules to the singlet microtubule tips extending from the A-tubules. No change in behavior was detected during the transition. This indicates that even if these microtubules differ in surface lattice, this does not affect the motility.

High-frequency vibration in flagellar axonemes with amplitudes reflecting the size of tubulin.

Flagellar axonemes of sea urchin sperm display high-frequency (approximately 300 Hz) vibration with nanometer-scale amplitudes in the presence of ATP (Kamimura, S., and R. Kamiya. 1989. Nature (Lond.). 340:476-478). The vibration appears to represent normal mechanochemical interaction between dynein and microtubules because the dependence of the frequency on MgATP concentration is similar to that of the axonemal motility, and because it is inhibited by micromolar concentrations of vanadate. In this study a two-dimensional photo-sensor was used to characterize this phenomenon in detail. Several new features were revealed. First, the vibration was found to be due to a back-and-forth movement of the doublet microtubules along the axonemal length. Two beads attached to different parts of the same axoneme vibrated in unison, i.e., synchronized exactly in phase. This suggested that the outer doublet can be regarded as a stiff rod in vibrating axonemes. Second, evidence was obtained that the amplitude of the vibration reflected the number of active dynein arms. Third, under certain conditions, the vibration amplitude took stepwise values of 8 x N + 4 nm (N = 0, 1, 2, 3, or 4), indicating that the amplitude of microtubule sliding was limited by the size of tubulin dimer (8 nm) or monomer (4 nm). To explain this phenomenon, a model is presented based on an assumption that the force production by dynein is turned off when dynein is subjected to tensile force; i.e., dynein is assumed to be equipped with a feedback mechanism necessary for oscillation.

Case of pregnancy in two cows with unicorn horn of the uterus either by artificial insemination at ipsilateral or embryo transfer at contralateral corpus luteum in the ovary.

Two Holstein heifers and a cow were diagnosed with White Heifer Disease by ultrasonography. Case 1 was a 14 month-old heifer with aplasia of both sides of the uterine horn. In case 2, a primiparous cow and case 3, an 18 month-old heifer, both showed aplasia of the right uterine horn. Case 2 became pregnant by artificial insemination at ipsilateral ovulatory follicle and corpus luteum in the left ovary, while case 3 became pregnant by embryo transfer at 7 days after oestrus with contralateral corpus luteum in the right ovary.

Experimental liver cirrhosis induced by alcohol and iron.

To determine if alcoholic liver fibrogenesis is exacerbated by dietary iron supplementation, carbonyl iron (0.25% wt/vol) was intragastrically infused with or without ethanol to rats for 16 wk. Carbonyl iron had no effect on blood alcohol concentration, hepatic biochemical measurements, or liver histology in control animals. In both ethanol-fed and control rats, the supplementation produced a two- to threefold increase in the mean hepatic non-heme iron concentration but it remained within or near the range found in normal human subjects. As previously shown, the concentrations of liver malondialdehyde (MDA), liver 4-hydroxynonenal (4HNE), and serum aminotransferases (ALT, AST) were significantly elevated by ethanol infusion alone. The addition of iron supplementation to ethanol resulted in a further twofold increment in mean MDA, 4HNE, ALT, and AST. On histological examination, focal fibrosis was found < 30% of the rats fed ethanol alone. In animals given both ethanol and iron, fibrosis was present in all, with a diffuse central-central bridging pattern in 60%, and two animals (17%) developed micronodular cirrhosis. The iron-potentiated alcoholic liver fibrogenesis was closely associated with intense and diffuse immunostaining for MDA and 4HNE adduct epitopes in the livers. Furthermore, in these animals, accentuated increases in procollagen alpha 1(I) and TGF beta 1 mRNA levels were found in both liver tissues and freshly isolated hepatic stellate cells, perisinusoidal cells believed to be a major source of extracellular matrices in liver fibrosis. The dietary iron supplementation to intragastric ethanol infusion exacerbates hepatocyte damage, promotes liver fibrogenesis, and produces evident cirrhosis in some animals. These results provide evidence for a critical role of iron and iron-catalyzed oxidant stress in progression of alcoholic liver disease.

The use of a deslorelin implant (GnRH agonist) during the late embryonic period to reduce pregnancy loss.

Embryonic and fetal mortality reduce reproductive performance of lactating dairy cows. The objectives of this study were to reduce pregnancy loss by administering a deslorelin implant (GnRH agonist) during the late embryonic period, to reduce follicular growth, induce accessory corpora lutea, and increase plasma progesterone concentrations. Lactating dairy cows received an implant containing 2.1 mg of deslorelin (Deslorelin group; n = 89) or no treatment (Control group; n = 92) on Day 27 of pregnancy. Pregnancy, ovarian structures and plasma progesterone concentrations were determined on Days 27 and 45, and pregnancy was re-confirmed on Day 90. On Day 45, mean +/- S.E.M. numbers of class 2 (6-9 mm; 0.72+/-0.19) and class 3 (> or = 10 mm; 0.86 +/- 0.12) follicles for cows in the Deslorelin group were lower (P < 0.01) than the numbers of class 2 (1.90 +/- 0.18) and class 3 (1.92 +/- 0.12) follicles for cows in the Control group. On Day 45, the number of accessory corpora lutea for cows in the Deslorelin group (1.80 +/- 0.07) were greater (P < 0.01) than for cows in the Control group (1.31 +/- 0.07). On Day 45, plasma progesterone concentration was increased (P < 0.01) for cows in the Deslorelin group (8.03 +/- 0.33 ng/mL) compared to cows in the Control group (6.40 +/- 0.31 ng/mL). Pregnancy losses did not differ between Days 27 and 45 and Days 45 and 90 for cows in the Control (15.2 and 11.0%, respectively) and Deslorelin groups (20.2 and 10.5%, respectively). However, in the Deslorelin group, pregnancy loss between Days 45 and 90 was lower (P < 0.05) for cows that formed an accessory CL (0%) compared to cows that did not form an accessory CL (16.1%).

1H NMR study of dynamics and thermodynamics of acid-alkaline transition in ferric hemoglobin of a midge larva (Tokunagayusurika akamusi).

One of the components of hemoglobin from the larval hemolyph of Tokunagayusurika akamusi possesses naturally occurring substitution at the E7 helical position (Leu E7) [M. Fukuda, T. Takagi, K. Shikama, Biochim. Biophys. Acta 1157 (1993) 185-191]. Its oxygen affinity is almost comparable to those of mammalian myoglobins and it exhibits Bohr effect. Both acidic and alkaline forms of the ferric hemoglobin have been investigated using 1H NMR in order to gain insight into molecular mechanisms for relatively high oxygen affinity and Bohr effect of this protein. The NMR data indicated that the acidic form of the protein possesses pentacoordinated heme, and that the alkaline form possessing OH- appears with increasing the pH value. pH titration yielded a pK value of 7.2 for the acid-alkaline transition, and this value is the lowest among the values reported so far for various myoglobins and hemoglobins. The kinetic measurements of the transition revealed that the activation energy for the dissociation of the Fe-bound OH-, as well as the dissociation and association rates, decrease with increasing the pH value. These pH dependence properties are likely to be related to the Bohr effect of this protein.

Appearance of cross linked proteins in human atheroma and rat pre-fibrotic liver detected by a new monoclonal antibody.

A new monoclonal antibody against malondialdehyde (MDA)-treated low density lipoprotein (LDL) was raised using homogenate of human atheroma as immunogen. This antibody, DLH2, was obtained by selecting the clones which did not react to native LDL but did react to copper-induced oxidized LDL (OxLDL). DLH2 showed a greater reactivity to MDA-LDL than to OxLDL. When LDL was treated with various aldehyde containing reagents, treatment of LDL with glutaraldehyde or MDA greatly increased the reactivity to the antibody, while LDL treated with 2,4-hexadienal or 4-hydroxynonenal was not reactive. Among many proteins tested, high density lipoprotein, bovine serum albumin and hemoglobin showed significant reactivity to DLH2 after they were treated with MDA or glutaraldehyde. When low density and high density lipoproteins treated with MDA were subjected to immunoblot analysis, newly formed products larger than the original apolipoproteins were detected with the antibody, suggesting that this antibody recognizes aggregated proteins with divalent short chain cross linkers. The antigenic materials were shown by immunohistochemical analysis to be present in foamy macrophages in human atheromatous lesions. DLH2 antigen did not colocalize either with apolipoprotein B. Furthermore, we found a massive accumulation of the antigenic material in Kupffer cells in the liver of rats treated with alcohol and carbonyl iron, a model of hepatic fibrosis due to oxidative stress. These results suggest the presence of cross linked proteins in damaged tissues.

Presence of human papilloma virus DNA in pelvic lymph nodes can predict unexpected recurrence of cervical cancer in patients with histologically negative lymph nodes.

Patients without any evidence of lymph node metastases are supposed to have a fair prognosis, but some of these patients develop recurrent disease unexpectedly after surgery. The object of this study is to examine whether the detection of human papilloma virus (HPV) DNA could be used as a diagnostic marker to predict such recurrences. Two hundred and thirty-six patients undergoing radical hysterectomy and pelvic lymphadenectomy for stage Ib and II cervical cancer at Okayama University Hospital (Japan) from 1988-1994 were reviewed, and only those cases positive for HPV-16 or HPV-18 in primary sites were included in this survey. The E6-E7 region of the HPV genome was amplified by a sensitive nested PCR from archival pelvic lymph node specimens. HPV sequences identical to those of the primary sites were detected in histologically confirmed negative lymph nodes, regardless of histological type or HPV type of the primary lesion, in 9 of 10 patients who recurred within 4 years of surgery. In contrast, histologically confirmed negative lymph nodes from 12 patients with stage IIb disease without evidence of recurrent disease were all negative for the presence of HPV, except for 1 lymph node. The presence of HPV DNA in histologically negative nodes implies the possibility of early nodal involvement or coexistence of undetectable hematogenic dissemination and could therefore be used as a diagnostic marker to predict the unexpected recurrence of these patients.

Resynchronization of ovulation and timed insemination in lactating dairy cows I: use of the Ovsynch and Heatsynch protocols after non-pregnancy diagnosis by ultrasonography.

The objective was to compare pregnancy rates and pregnancy losses in lactating dairy cows that were diagnosed not pregnant and re-inseminated following either the Ovsynch or Heatsynch protocols. Also evaluated were the effects of stages of the estrous cycle, ovarian cysts and anestrus on pregnancy rates for both treatments. Non-pregnant cows (n = 332) as determined by ultrasonography on day 27 post-AI (study day 0) were divided into two groups. Cows in the Ovsynch group (n = 166) received GnRH on day 0, PGF2alpha on day 7, GnRH on day 9, and timed AI (TAI) 16 h later (day 10). Cows in the Heatsynch group (n = 166) received GnRH on day 0, PGF2alpha on day 7, estradiol cypionate (ECP) on day 8, and TAI 48 h later (day 10). Cows detected in estrus on days 8 and 9 were inseminated and included in the study. On day 0, cows were classified according to different stages of the estrous cycle, or presence of ovarian cysts or anestrus. Pregnancy rates were evaluated 27, 45 and 90 days after resynchronized AI. Overall, there was no difference in pregnancy rates on days 27, 45 and 90 between cows in the Ovsynch (25.2, 17.5, and 13.9%) and Heatsynch (25.8, 19.9, and 16.1%) groups. There was no difference in pregnancy losses from days 27 to 45 and days 45 to 90 for cows in the Ovsynch (25.0 and 17.9%) and Heatsynch (14.7 and 10.3%) groups. However, pregnancy rates were increased when cows in metestrus were subjected to the Heatsynch protocol and cows with ovarian cysts were subjected to the Ovsynch protocol.

Coffee but not green tea consumption is associated with prevalence and severity of hepatic steatosis: the impact on leptin level.

BACKGROUND/OBJECTIVES: Most of the studies that have investigated the association between coffee consumption and hepatic steatosis have been experimental and small-scale clinical studies. As a result, epidemiological studies are scarce. To clear the association, we conducted a cross-sectional study and investigated the effects of coffee consumption with those of green tea consumption. SUBJECTS/METHODS: We analyzed 1024 Japanese male workers. The diagnosis of hepatic steatosis was based on ultrasonography. We divided coffee and green tea consumption into the following three categories: non-drinker; 1-2 cups/day and ⩾3 cups/day. To investigate the association between hepatic steatosis and coffee or green tea consumption, we calculated the odds ratio (OR) and adjusted the means of leptin levels on each severity of hepatic steatosis. RESULTS: A total of 265 of our subjects (25.9%) were diagnosed with hepatic steatosis. The ORs of the group of subjects who drank >3 cups of coffee/day was significantly lower compared with that of the noncoffee drinker group (OR 0.59, 95% confidence intervals 0.38-0.90, P=0.03). Although there was a significant difference between coffee consumption and leptin level only in the asymptomatic group, we found a decreasing trend in the asymptomatic and moderate-severe hepatic steatosis group. We did not find the same relationships in green tea consumption. CONCLUSIONS: Although we did not find an association between hepatic steatosis and green tea consumption, coffee may have beneficial effects on hepatic steatosis. In addition, we produced one possible hypothesis that coffee consumption negatively associates with leptin levels in hepatic steatosis.

Differential catabolism of 22-oxacalcitriol and 1,25-dihydroxyvitamin D3 by normal human peripheral monocytes.

22-Oxacalcitriol [1,25-(OH)2-22oxa-D3] mimics the action of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in a variety of target tissues, including the systemic control of calcitriol metabolism. Similar to 1,25-(OH)2D3, 1,25-(OH)2-22oxa-D3 decreases the rate of 1,25-(OH)2D3 synthesis and accelerates its metabolic clearance rate. We have previously shown that in normal human monocytes, physiological concentrations of 1,25-(OH)2D3 and 1,25-(OH)2-22oxa-D3 determine identical suppression of 1,25-(OH)2D3 synthesis. Moreover, both sterols have a similar potency to induce vitamin D degradation through stimulation of the C24-hydroxylation pathway. In this study, we examined the ability of normal human monocytes to metabolize 1,25-(OH)2-22oxa-D3 and whether the enzymes involved are the same as those that catabolize 1,25-(OH)2D3. Time-course experiments demonstrated no detectable basal catabolic activity. However, exogenous 1,25-(OH)2D3 at physiological concentrations induced 1,25-(OH)2-22oxa-D3 degradation by normal human monocytes. Competition experiments showed that a 10-fold molar excess of unlabeled 1,25-(OH)2D3 inhibited tritiated-1,25-(OH)2-22oxa-D3 catabolism by 85%, whereas a 10-fold excess of unlabeled 1,25-(OH)2-22oxa-D3 reduced tritiated-1,25-(OH)2-22oxa-D3 catabolism by 33%. In contrast, although a 10-fold excess of unlabeled 1,25-(OH)2D3 reduced tritiated 1,25-(OH)2D3 catabolism by 60%, a 1000-fold excess of 1,25-(OH)2-22oxa-D3 was required to reduce tritiated 1,25-(OH)2D3 catabolism to this degree. The apparent Km for 1,25-(OH)2-22oxa-D3 was significantly higher than that of 1,25-(OH)2D3 (2.0 +/- 0.8 0.9 +/- 0.2 nM, respectively; P < 0.001) for the catabolic pathway induced by physiological concentrations of 1,25-(OH)2D3. Moreover, the presence of 0.65 nM 1,25-(OH)2D3 caused an additional increase in the Km for 1,25-(OH)2-22oxa-D3 (3.2 +/- 0.8 nM). These data suggest that 1,25-(OH)2-22oxa-D3 may be less accessible than 1,25-(OH)2D3 to the hydroxylases involved in vitamin D catabolism. The resulting prolonged biological half-life of the analog in certain target tissues may be involved in its selectivity.

The effect of 22-oxacalcitriol on serum calcitriol.

1,25-Dihydroxyvitamin D3 (1,25D) regulates its own levels in circulation by affecting its rates of synthesis and degradation, 22-Oxacalcitriol (OCT), a vitamin D analog with low calcemic activity, decreases circulating PTH levels, one of the regulators of renal 1 alpha-hydroxylase, and stimulates vitamin D degradation in vitro. The purpose of this study was to examine the effects of OCT administration on serum levels of 1,25D. In normal rats, OCT administration (4-200 ng, ip, daily for 5 days) caused a dose-dependent reduction in serum calcitriol levels. At a dose of 200 ng, OCT reduced serum 1,25D from 34.5 +/- 2.7 to 10.9 +/- 0.7 pg/ml (P less than or equal to 0.01) without significant changes in ionized Ca or phosphorus levels. The contribution of the suppression of PTH by OCT to the reduction of serum 1,25D was examined by administering OCT to parathyroidectomized (PTX) rats. Two hundred nanograms of OCT, ip, daily for 5 days significantly reduced serum calcitriol from 29.7 +/- 7.6 to 9.1 +/- 0.5 pg/ml (P less than or equal to 0.01) in rats fed a normal calcium diet. Because OCT increased total calcium (TCa) in this group from 7.4 +/- 0.1 to 9.5 +/- 0.3 mg/dl, similar doses of OCT were given to PTX rats fed a calcium-deficient diet. OCT decreased 1,25D from 58.9 +/- 8.9 to 10.3 +/- 0.4 pg/ml and increased TCa from 4.8 +/- 0.2 to 7.4 +/- 0.1 mg/dl. Comparison of serum 1,25D for identical TCa levels in PTX rats (normal calcium diet controls vs. calcium-deficient diet, OCT-treated) clearly indicates that OCT per se reduced serum 1,25D. Further support for a direct effect of OCT was provided by studies in PTX rats fed a low phosphorus diet. OCT decreased serum 1,25D from 125.8 +/- 15.6 to 10.9 +/- 0.6 pg/ml without significant changes in TCa. To further characterize the mechanisms involved in this effect, similar studies were performed in six normal dogs. Intravenous administration of 0.75 micrograms OCT every other day for 1 week decreased serum calcitriol from 25.4 +/- 3.2 to 12.2 +/- 1.3 pg/ml (P less than or equal to 0.002). Ionized Ca and phosphorus remained unchanged. Despite the short half-life of OCT in the circulation, 1,25D levels returned to basal concentrations 96 h after the last dose of OCT.(ABSTRACT TRUNCATED AT 400 WORDS)

gamma-Interferon-induced resistance to 1,25-(OH)2 D3 in human monocytes and macrophages: a mechanism for the hypercalcemia of various granulomatoses.

The hypercalcemia of various granulomatoses is caused by endogenous 1,25-dihydroxyvitamin D [1,25-(OH)2D3] overproduction by disease-activated macrophages. The inability of 1,25(OH)2D3 to suppress its synthesis in macrophages contrasts with the tight control of its production in macrophage precursors, peripheral blood monocytes (PBM). We examined whether 1,25(OH)2D3 resistance develops as PBM differentiate to macrophages or with macrophage activation. Normal human pulmonary alveolar macrophages (PAM) are less sensitive to 1,25(OH)2D3 than PBM, despite similar vitamin D receptor content; however, both PBM and PAM respond to exogenous 1,25-(OH)2D3 by inhibiting 1,25(OH)2D3 synthesis and inducing 1,25(OH)2D3 degradation through enhancement of 24-hydroxylase mRNA levels and activity. The human monocytic cell line THP-1 mimics PAM in 1,25(OH)2D3 synthesis and sensitivity to exogenous 1,25(OH)2D3. We utilized THP-1 cells to examine the response to 1,25(OH)2D3 with macrophage activation. Activation of THP-1 cells with gamma-interferon (gamma-IFN) enhances 1,25(OH)2D3 synthesis 30-fold, blocks 1,25-(OH)2D3 suppression of its synthesis, and reduces by 42.2% 1,25-(OH)2D3 induction of its degradation. The antagonistic effects of gamma-IFN are not merely restricted to enzymatic activities. In THP-1 cells and in normal PBM, gamma-IFN inhibits 1,25-(OH)2D3 induction of 24-hydroxylase mRNA levels without reducing mRNA stability, suggesting gamma-IFN inhibition of 1,25(OH)2D3 transactivating function. These results explain 1,25(OH)2D3 overproduction in granulomatoses and demonstrate potent inhibition by gamma-IFN of 1,25(OH)2D3 action in immune cells.

ATP hydrolysis coupled to microtubule sliding in sea-urchin sperm flagella.

Using sea urchin (Hemicentrotus pulcherimus) sperm flagella, ATP hydrolysis coupled to sliding movement of microtubules was investigated. Flagellar axonemes were pretreated with trypsin and the microtubules induced to slide by addition of ATP (50-1,000 microM) at 0-20 degrees C. Motion-dependent hydrolysis of ATP was observed immediately after the addition of ATP, the rate of which was higher than that of steady state hydrolysis in axonemes without trypsin-treatment, or after complete disintegration. The rate of hydrolysis of ATP divided by the sliding velocity of microtubules reflects the ATP consumption necessary per unit distance of microtubule sliding. This parameter varied according to the experimental conditions in that it increased when the ATP concentration or temperature was decreased. Our results suggest that there is not a strict stoichiometric relationship between ATP hydrolysis and sliding distance in the dynein-tubulin system, indicating that the mechanochemical coupling is different from that in beating axonemes.

Co-localisation of insulin-like growth factor II and the proliferation marker MIB1 in hepatocellular carcinoma cells.

AIM: To assess the effect of insulin-like growth factor II (IGF-II) on proliferation of hepatocellular carcinoma (HCC) cells. METHODS: Expression of IGF-II mRNA and protein was detected in 10 archival HCC specimens using in situ hybridisation and immunohistochemistry, respectively. Expression of the Ki-67 antigen, a proliferation marker, was determined immunohistochemically on the same sections. RESULTS: Increased expression of IGF-II mRNA and protein was detected in five of the 10 HCCs in cells located at the periphery of tumour nests. The pattern of localisation of IGF-II was almost identical with that of Ki-67 antigen. CONCLUSIONS: Most of the Ki-67 antigen positive cells co-expressed IGF-II, suggesting that IGF-II may act as an autocrine or paracrine growth factor, and may play an important role in the development of HCC.

Congenital muscular dystrophy with partial deficiency of merosin.

We present a Japanese patient who has congenital muscular dystrophy, with partial merosin deficiency. The patient had characteristic findings of clinical features and brain MRI. Muscle biopsy showed advanced muscular dystrophy, with greatly reduced muscle fibers and massive infiltration of interstitial connective and fatty tissues. On immunostaining for cytoskeletal proteins, merosin was greatly reduced. The other cytoskeletal proteins, including dystrophin and 50 kDa alpha-sarcoglycan were normally expressed around all muscle fibers.

Lowered sperm motility in subordinate social status of mice.

The correlation between social status and sperm motility of mice was investigated. From 5 to 15 weeks of age, mice were kept under two housing conditions, i.e., in pairs or in isolation. The social dominance in the paired mice was determined with the resident-intruder tests, which were carried out from 8 to 15 weeks of age. At the end of 15 weeks of age, sperm activity, weights of reproductive organs, and serum testosterone were determined. It was revealed that the sperm motility of dominant mice was significantly higher than that of the subordinates. The sperm motility of the isolated mice was also significantly higher than the subordinates. It was suggested that the subordinate social status lowered sperm motility.

Influence of social dominance and female odor on the sperm activity of male mice.

In mammals, sperm activity is known to be varied largely according to individuals though physiological reasons have not been clarified yet. In our previous study [Koyama S, Kamimura S. Lowered sperm motility in mice of subordinate social status. Physiol Behav 1999;65:665-669.], we showed that sperm motility was higher in the dominant mice than the subordinate mice, by which it was suggested that social factors could affect sperm activity in mammals. In the present study, we investigated how the observed influence of social dominance would be modified by the existence of females. From 5 to 15 weeks of age, male mice were pair housed and were kept under three different housing conditions: (1) with females; (2) with bedding soiled by females; and (3) control group. The social dominance of the paired males was determined by resident-intruder tests that were carried out from 8 to 15 weeks of age. At the end of 15 weeks of age, sperm activity, weights of organs, level of serum testosterone and corticosterone were determined. It was revealed that sperm density was higher and weight of preputial glands was heavier in dominants than in subordinates when they were kept with females or female bedding. In the subordinates, however, there were no differences among the three housing conditions; that is, there were no female effects on the subordinates. On the other hand, sperm motility was high in the dominants of control group, low in the subordinates, and lower in the dominants that were kept with females. The dominants of the males that were kept with females showed high aggressiveness, and there were negative correlationships to be seen between aggressiveness and sperm motility. It was suggested that: (1) Female odor promotes spermatogenesis of the dominants, but it does not promote that of the subordinates. (2) Sperm motility is more affected by social dominance than by female odor. (3) Excessive aggressiveness has negative influence on sperm motility.

Increased expression of transforming growth factor-alpha in a patient with recurrent hepatocellular carcinoma following partial hepatectomy.

A 45-year-old woman with chronic hepatitis B underwent partial hepatectomy for hepatocellular carcinoma (HCC). However, the HCC recurred 2 months after surgery and rapid progression of the disease resulted in her death. Immunohistochemistry showed that transforming growth factor-alpha (TGFalpha) was barely expressed in the liver specimens obtained at hepatic resection, whereas autopsy specimens were strongly stained with anti-TGFalpha antibody in the cytoplasm of both non-tumourous and tumourous liver cells. A higher level of Ki67 expression, a proliferating marker, was observed in the recurrent HCC, similar to that of TGFalpha. Thus, we speculate that the partial hepatectomy increased the level of TGFalpha leading to recurrence and progression of HCC through an autocrine/paracrine mechanism.

Enzymatic conversion of cephamycin C by D-amino acid oxidase from Trigonopsis variabilis.

D-Amino acid oxidase (EC 1.4.3.3) systems from Trigonopsis variabilis SANK 59963 were found to catalyze cephamycin C. The reaction products were assigned to 7 beta-(5-carboxy-5-oxovalerylamido)-7 alpha-methoxy-3-carbamoyl-3-cephem-4-carboxylic acid, and 7 beta-(4-carboxy-butyrylamido)-7 alpha-methoxy-3-carbamoyl-3-cephem-4-carboxylic acid, respectively. D-Amino acid oxidase from hog kidney was not able to catalyze cephamycin C.