Primary erythrocytosis in a Japanese black calf: a case report

An 8-month-old Japanese Black heifer with severe erythropoietic symptoms was subjected to clinical, histological and cytological examinations. During the 1 month clinical observation period, severe increases in RBC count, packed cell volume and haemoglobin concentration were observed. The plasma erythropoietin (Epo) concentration of the heifer (20.7 mIU/ml) was similar to that observed in normal control heifers. Blood gas examinations of the arterial and venous blood revealed low levels of partial pressure O(2) (PaO(2)), partial pressure CO(2) (PaCO(2)) and O(2) saturation (SaO(2)), while the blood pH was within the normal range. Gross lesions could not be detected. However, microscopic observation revealed severe proliferation of erythroblasts in the bone marrow and in the spleen without evidence of neoplastic changes. Based on these clinical and pathological examinations, we diagnosed the heifer as being the first case of primary erythrocytosis in Japanese Black cattle.

Ovarian carcinomas with neuroendocrine differentiation: Review of five cases referring to immunohistochemical characterization

AIM

To review five ovarian carcinomas with varying degrees of neuroendocrine differentiation (ND) using an immunohistochemical study focused on the relationship with morphological features.

METHODS

ND was immunohistochemically analyzed using 21 antibodies by an indirect immunoperoxidase method, and ploidy pattern was analyzed using paraffin sections.

RESULTS

The tumors were divided according to tumor cell size into 'small-sized' for case 1, 'intermediate-sized' for cases 2 and 3, and 'large-sized' for cases 4 and 5. Expressions of neuroendocrine markers and argyrophil reaction tended to be strengthened as tumor cell size increased. Cases 1, 2 and 3 showed diploid pattern and cases 4 and 5 showed aneuploid pattern.

CONCLUSION

ND of ovarian carcinomas is closely related to morphological features represented by the cell size. Therefore, ovarian carcinomas with ND should be defined because the disease entity is not successfully integrated irrespective of the highly malignant potential.

New HSN2 mutation in Japanese patient with hereditary sensory and autonomic neuropathy type 2

The authors report a Japanese patient with hereditary sensory and autonomic neuropathy type 2 (HSAN2) who has a new mutation of the HSN2 gene. The pathologic findings of the patient matched those of Canadian patients. They identified a homozygous 1134-1135 ins T mutation, resulting in a frameshift, and the subsequent premature stop codon at residue 378. These observations support the hypothesis that HSN2 is a causative gene for HSAN2.

Alteration of product specificity of cyclodextrin glucanotransferase from Thermococcus sp. B1001 by site-directed mutagenesis

Cyclodextrin glucanotransferase (CGTase) from the hyperthermophilic archaeon Thermococcus sp. B1001 catalyzed the production predominantly of alpha-cyclodextrin (CD) from starch (Tachibana, Y. et al., Appl. Environ. Microbiol., 65, 1991-1997, 1999). The CGTase gene (cgtA) from this strain was cloned and sequenced. It was composed of 2217 nucleotides, and encoded a protein (739 amino acids) with a molecular mass of 83,240 Da. Recombinant CgtA expressed in Escherichia coli also catalyzed the production predominantly of alpha-CD from starch, as did native CgtA from strain B1001. Based on a substrate binding model of Bacillus circulans no. 8 CGTase, Tyr100, Trp191 and Tyr267 were specified to locate the spiral amylose and to minimize the size of the CD by saccharide aromatics interaction. In order to determine the critical residue for catalyzing production predominantly of alpha-CD, site-directed mutations were introduced in CgtA (Y100W, Tyr100-->Trp; W191Y, Trp191-->Tyr; W191F, Trp191-->Phe; Y267W, Tyr267-->Trp; Y267F, Tyr267-->Phe). Analysis of the reaction products by HPLC revealed that the mutant enzyme Y267W produced more beta- and gamma-CD than the wild-type enzyme. However, the other mutants still produced high levels of alpha-CD, suggesting that Tyr267 plays a critical role in alpha-CD production catalyzed by B1001 CGTase.

Effects of high concentrations of energy sources and metabolites on suspension culture of Chinese hamster ovary cells producing tissue plasminogen activator

A high-concentration medium was developed for the high-density cultivation of Chinese hamster ovary (CHO) cells to produce tissue plasminogen activator (tPA). First, the effects of the concentrations of several medium components on the growth and metabolism of CHO cells were studied particularly in relation to the serum concentration, in order to develop a suitable concentrated medium. High concentrations of serum, glucose, lactate, and glutamine and a low ammonia concentration increased the specific growth rate and decreased the specific tPA production rate. Among these components, the effect of the serum concentration was the most significant. There was an inverse correlation between the specific rates of cell growth and tPA production. Using a medium containing glutamine at twice the concentration of the original medium (F-12) allowed the medium volume to be reduced to seven-ninths that of the original, without any reduction in tPA productivity. When the F-12 medium was supplemented five-fold with amino acids and vitamins, the total amount of tPA produced, specific rate of tPA production, and yield of tPA per unit volume of medium employed were respectively enhanced 1.7, 1.5, and 3.6 times. As a consequence, the frequency of medium exchange could be reduced. The results strongly indicate that the supplementation of nutrient amino acids and vitamins to a medium with a low concentration of serum are the most critical factors for cost-effective tPA production in high-density cell cultivation.

Effect of polyamines on histone-induced DNA compaction of hyperthermophilic archaea

The effect of polyamines on histone-mediated DNA compaction was examined in vitro with archaeal histone HpkA from Pyrococcus kodakaraensis KOD1. An agarose gel mobility-shift experiment indicated that histone-bound DNA (compacted DNA) was further compacted by addition of a polyamine (putrescine, spermidine, or spermine) or its acetylated form (N-acetylputrescine, N1-acetylspermidine, N8-acetylspermidine, or N1-acetylspermine) when the mixture was incubated at above 75 degrees C. Spermine was most effective in compaction enhancement among all the polyamines tested. A high concentration of potassium ion (1.0 M) did not stabilize the compacted form of DNA even though double-stranded DNA was stably maintained against thermal denaturation at elevated temperatures under this condition. It appears likely that multivalent polyamines have a nucleosome maintenance function in hyperthermophilic archaea in high-temperature environments.

Effect of antioxidants on the apoptosis of CHO cells and production of tissue plasminogen activator in suspension culture

The effects of antioxidants on the apoptosis of Chinese hamster ovary (CHO) 1-15,500 cells and production of tissue plasminogen activator (tPA) in suspension culture were investigated. After cell growth to 2 x 10(5) cells/ml in Ham's F12 medium containing 10% newborn bovine serum (NBS) in a spinner bottle, CHO cells were maintained for 6 d in Ham's F12 medium containing 0 or 0.4% NBS and 10 mM antioxidants, namely, l-ascorbic acid 2-phosphate (VCP) or the reduced form of glutathione (GSH). The viable cell concentrations at day 6 in the serum-free culture with GSH and in the low-serum culture wiht VCP or GSH were 0.57, 1.04 and 1.69 x 10(5) cells/ml, respectively, while those in the serum-free and low-serum cultures without the antioxidants were only 2.33 and 1.17 x 10(3) cells/ml, respectively. The percentages of apoptotic cells in the serum-free and low-serum cultures with VCP (73.2, 44.6%) and GSH (76.9, 38.6%) measured using a flowcytometer after annexin V-FITC/propidium iodide staining were markedly lower than those in the cultures without antioxidants (96.3, 92.5%). The percentage of cells having a high mitochondrial membrane potential among the viable cells in the cultures with antioxidants determined using a flowcytometer after 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide staining was clearly higher than those in the cultures without the antioxidants. The production of tPA in the serum-free and low-serum media with VCP (0.282, 2.92 mg/l) or GSH (1.01, 1.61 mg/l) was markedly higher than that in the cultures without the antioxidants (0.275, 0.689 mg/l). Consequently, the suppression of apoptosis through the maintenance of the membrane potential of mitochondria by VCP or GSH resulted in a marked increase in tPA production by CHO cells in the serum-free and low-serum cultures.

Characterization of FtsZ homolog from hyperthermophilic archaeon Pyrococcus kodakaraensis KOD1

The gene of bacterial type ftsZ homolog in hyperthermophilic archaeon, Pyrococcus kodakaraensis KOD1 (Pk-ftsZ), was identified. The gene product of the Pk-ftsZ gene is composed of 380 amino acids with a molecular mass of 41,354 Da. In the deduced amino acid sequence of the Pk-ftsZ gene, a glycine-rich sequence (Gly-Gly-Gly-Thr-Gly-Ala-Gly) implicated in GTP binding was well conserved. The Pk-ftsZ gene was overexpressed using Escherichia coli as a host and the recombinant protein was purified. The purified Pk-FtsZ protein exhibited GTPase activity with optimum temperatures higher than 80 degrees C. However, the protein showed little GTPase activity at 40 degrees C, indicating that a high reaction temperature is required for the GTPase activity in accordance with the thermophilic nature of P. kodakaraensis KOD1. The GTP-binding ability of Pk-FtsZ protein could also be detected by UV-induced cross-linking of a protein to [alpha-32P] GTP. The Pk-ftsZ gene was expressed in E. coli cells with a temperature-sensitive ftsZ mutation, E. coli ftsZ84 (ts), but its mutant phenotype of elongated cell form at a nonpermissive temperature (42 degrees C) could not be compensated, possibly because of the thermophilic nature of the Pk-FtsZ. Pk-FtsZ could form protofilaments in a GTP-dependent manner at 90 degrees C. Results of phylogenetic analysis suggest that there might be additional factors required for formation of the Z ring in P. kodakaraensis KOD1.

Enhanced signal transduction by a directly fused protein of interleukin-6 and its receptor

In order to develop a new type of agonist for the interleukin 6 (IL-6) signal, the gene encoding a directly fused protein (DFP) was constructed by joining the N-terminal portion of IL-6 and the C-terminal (soluble) portion of IL-6R (sIL-6R) without using a flexible polypeptide linker. The biological activity if DFP from a recombinant Pichia pastoris was examined by growth stimulation of IL-6-dependent BAF130 cells expressing human gp130, a membrane receptor. The recombinant DFP exhibited a much stronger growth stimulation (10 times) than the independent IL-6 and sIL-6R (IL-6/sIL-6R), mainly because association of the IL-6 and IL-6R could be maintained even at lower concentrations of DFP. Surface plasmon resonance (SPR) analysis showed that DFP bound to the extracellular portion of gp130 in the biphasic mode, and the dissociation constants of DFP for two phases were the same as those of IL-6/sIL-6R. In cells treated with DFP, stimulation of Stat3 phosphorylation was maintained for a longer period (150 min) than in cells treated with IL6/Il-6R, suggesting that the signal mediated by the DFP was more durable than that mediated by IL-6/sIL-6R, although the signal transduction mechanisms are almost the same for both DFP and IL-6/IL-6R. Therefore, the stronger activity of DFP was attributed to the maintained association of its subunits and/or prolonged phosphorylation of Stat3.

Selective retension of active cells employing low centrifugal force at the medium change during suspension culture of Chinese hamster ovary cells producing tPA

The effect of centrifugal force applied for cell separation at the medium change on the growth, metabolism and tissue plasminogen activator (tPA) productivity of Chinese hamster ovary (CHO) cells suspension culture was investigated. The viability of the precipitated cells increased exponentially as the centrifugal force decreased. However, the cell recovery was lower than 91% when centrifugal forces applied for 5 min was less than 67 x g. In cultures incubated for 474 h with 7 medium changes employing centrifugal forces ranging from 67 to 364 x g, a centrifugal force lower than 119 x g resulted in higher specific rates of growth, glucose consumption, and lactate and tPA production during the whole culture period. On the other hand, daily centrifugation at 67 to 537 x g without discarding the supernatant had no effect on the specific rates. The cultures inoculated with cells precipitated at a centrifugal force of 67 x g showed apparently higher specific rates of metabolism compared to those inoculated with cells in the supernatant. The cells in the supernatant and the precipitate obtained following centrifugation at 67 x g have average diameters of 15.5 and 17.4 microm, respectively. The intracellular contents of amino acids, especially nonessential amino acids, of the precipitated cells were markedly higher than those of the cells in the supernatant. These results indicate that large cells with high amino acid content and metabolic activity were selectively retained in the culture by means of centrifugation at low forces such as 67 x g. Consequently, application of a low centrifugal force is recommended for medium change in order to maintain higher specific productivity of suspended mammalian cells in perfusion culture.

Unique nucleoid structure during cell division of Thermococcus kodakaraensis KOD1

The nucleoid structure and the partition in the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 were observed by a combination of phase-contrast microscopy and fluorescence microscopy. The nucleoids occurred as rounded fluorescent foci centrally located in the cells and as differences in fluorescence intensity between exponential and stationary phases. The cellular space occupied by the nucleoid in the stationary phase was larger than that in the exponential phase. Various shapes of nucleoid in the exponential-phase cells were observed, indicating that nucleoid separation was processed under cell cycle control. The number of cells which showed distinctive division stages was counted and the proportions of dividing cells were determined. About half of the observed cells were in the replication stage. More than 40% of the counted cells possessed a fully replicated but not separated form of nucleoid. Only 8% of the total cells clearly showed visible constriction. These results suggested that the post-replication period before cell division was relatively as long as the eucaryal gap period (G2); however, the period of visible cell constriction was almost the same as that of the bacteria.

Gene analysis and enzymatic properties of thermostable beta-glycosidase from Pyrococcus kodakaraensis KOD1

A beta-glycosidase with broad substrate specificity was identified from a hyperthermophilic archaeon, Pyrococcus kodakaraensis KOD1. The gene encoding beta-glycosidase (Pk-gly) consists of 1449 nucleotides corresponding to a polypeptide of 483 amino acids. The protein showed similarity with other beta-glycosidases from family-1 glycosyl hydrolases, in particular, it showed high identity to beta-mannosidase from P. furiosus (55.7%), beta-glycosidase from Sulfolobus solfataricus (42.7%) and beta-glucosidase from P. furiosus (41.9%). The cloned gene was expressed in Escherichia coli and the recombinant protein was purified. The beta-glycosidase showed optimal activity at pH 6.5 and at an extremely high temperature of 100 degrees C, and had a half-life of 18 h at 90 degrees C. The beta-glycosidase hydrolyzed various pNp-beta-glycopyranosides, with kcat K(m) values in the order of pNp-beta-glucopyranoside = pNp-beta-mannopyranoside > pNp-beta-galactopyranoside > pNp-beta-xylopyranoside. pNp-beta-mannopyranoside was the substrate exhibiting the lowest K(m) value [0.254 mM] with a kcat K(m) ratio comparable to that of pNp-beta-glucopyranoside. This substrate specificity was distinct from previously reported beta-glycosidases. We observed that the region in PK-Gly corresponding to the fifth alpha-helix and beta-strand region of beta-glycosidase from S. solfataricus, which constitutes a large portion of the channel for substrate incorporation, displayed a chimeric structure, with the N-terminal region similar to beta-glycosidases and the C-terminal region similar to beta-mannosidases. An exo-type hydrolytic activity and transglycosylation activity were also observed towards cellooligomers.

Experimental study of bone formation around a titanium rod with beta-tricalcium phosphate and prostaglandin E2 receptor agonists

beta-Tricalcium phosphate (beta-TCP) is an excellent bone-filling material that is completely absorbed by the body and replaced by autologous bone. Unfortunately, its mechanical strength is low, rendering its application at loaded regions difficult. The purpose of this study is to evaluate the histological and mechanical effects of single and combined use of beta-TCP and EP4 agonist on bone formation around a titanium rod. beta-TCP was loaded into the femoral bone marrow from the distal end of the femur, where the titanium implants were inserted, and the animals received twice-daily subcutaneous injections of EP4 agonist. Group I received the rod only and was designated the control group; group II received EP4 agonist only; group III received beta-TCP only; and group IV received both beta-TCP and EP4 agonist. Examination of decalcified specimens revealed favorable bone formation in all treatment groups compared with that in group I, with the most active bone formation seen in group IV. Mechanical evaluation revealed significant differences in maximum pull-out force compared with group I at weeks 4 and 8. There were no differences between groups II and III at either week 4 or 8, but the values seen in group IV at weeks 4 and 8 were significantly higher compared with the other groups. Combined use of beta-TCP and EP4 agonist is expected to compensate for bone defects resulting from revision total joint arthroplasty and to achieve stability at an early stage.

Acute improvement of atrial mechanical stunning after electrical cardioversion of persistent atrial fibrillation: comparison between biatrial and single atrial pacing

OBJECTIVE

To evaluate the acute effects of atrial pacing at different pacing sites on mechanical stunning after cardioversion of atrial fibrillation (AF).

SETTING

Tertiary referral centre.

PATIENTS

20 patients with persistent AF were studied.

INTERVENTIONS

Spontaneous echo contrast (SEC), left atrial appendage emptying velocity (LAAEV), and left atrial appendage emptying fraction (LAAEF) were assessed by transoesophageal echocardiography (TOE) during AF, after conversion to sinus rhythm, and during atrial pacing from the right atrial appendage, left lateral atrium, and both atria simultaneously. Transmitral inflow velocity of the atrial wave (TMIF-A) by TOE and the maximum P wave duration in 12 lead ECG were also measured during sinus rhythm and atrial pacing.

MAIN OUTCOME MEASURES

Comparison of atrial mechanical function and P wave duration in 12 lead ECG during atrial pacing from different sites after cardioversion of AF.

RESULTS

Compared with sinus rhythm, atrial pacing at 80 beats/min increased LAAEV from mean (SD) 14.6 (10.1) to 33.4 (19.8) cm/s (p = 0.001), LAAEF from 13.8 (8.5) to 32.1 (11.2)% (p < 0.001), and TMIF-A from 24.6 (11.9) to 45.6 (21.0) cm/s (p < 0.001) and reduced SEC grade from 2.6 (1.0) to 1.6 (0.9) (p < 0.001). These effects had a positive force-frequency relation. Biatrial pacing produced the shortest P wave duration and resulted in the most significant improvement in atrial function (LAAEV, 33.2 (19.3) v 53.7 (23.9) cm/s, p = 0.0001; LAAEF, 31.9 (11.1) v 46.2 (12.6)%, p < 0.0001; TMIF-A, 37.7 (18.3) v 54.1 (21.2) cm/s, p < 0.001; SEC grade, 1.4 (1.1) v 0.8 (0.9), p = 0.001, right atrial appendage versus biatrial pacing).

CONCLUSIONS

Atrial pacing at increased rates can improve atrial mechanical function after cardioversion of persistent AF. Biatrial pacing may be the most effective technique to reverse atrial mechanical stunning.

Aberrant Nuclear/Cytoplasmic Localization and Gene Mutation of β-Catenin in Classic Pulmonary Blastoma

It is now known that gene mutation of beta-catenin with subsequent nuclear/cytoplasmic (N/C) overaccumulation of the protein plays an important role in tumorigenesis of various organs. We recently demonstrated that low-grade adenocarcinoma of the fetal lung type (L-FLAC)/well-differentiated fetal adenocarcinoma (WDFA), the epithelial prototype of classic pulmonary blastoma (CPB), shows N/C localization of beta-catenin with genetic mutation. This prompted us to further investigate the state of beta-catenin abnormality in CPB and related neoplasms. We studied 9 lung tumors previously diagnosed as biphasic pulmonary blastoma (PB). Histologically, 4 cases (median age 34 years) were CPB with l-FLAC/WDFA as the epithelial component, whereas 5 cases (median age 65 years) were a variant of carcinosarcoma with high-grade FLAC/clear cell adenocarcinoma with fetal lung features as the epithelial component, which we term the blastomatoid variant of carcinosarcoma (BCS). Immunohistochemically, all 4 CPBs showed aberrant N/C localization of beta-catenin both in the epithelial and mesenchymal components, with especially high staining intensity in the budding glands and morules. In contrast, all 5 BCSs showed preserved or diminished membranous expression and no significant N/C expression of beta-catenin in the epithelial component, and absent or focal N/C expression of beta-catenin in the mesenchymal component. Mutational analysis of exon 3 of the beta-catenin gene revealed that 3 CPBs harbored missense mutations (S29F, S37F, and S37F), whereas none of the 5 BCSs had this mutation. This study suggests that beta-catenin gene mutations may play a role in the tumorigenesis of CPB. Although CPB and BCS have often been grouped together as biphasic PB, they are different entities based on immunohistochemical and molecular analysis of beta-catenin. Immunostaining for beta-catenin is useful for the discrimination.

Histopathological studies on viral nervous necrosis of sevenband grouper, Epinephelus septemfasciatus Thunberg, at the grow-out stage

Abstract Viral nervous necrosis caused by sevenband grouper nervous necrosis virus (SGNNV) has occurred in grow-out stages (0-3 years old) of sevenband grouper, Epinephelus septemfasciatus, since the 1980s. In the present study, based on histopathological features of the central nervous system (CNS) in naturally diseased fish, pernasal infection experiments using grow-out fish were performed and pernasal infection was established as a putative invasion route of SGNNV. The definite SGNNV-targeted cells were determined by histopathological studies including indirect fluorescent antibody test and electron microscopy. Nerve cells in the olfactory lobe were most extensively necrotized with vacuolation followed by infiltration of microglia and macrophages. Purkinje cells and Golgi cells were extensively infected in the cerebellum. Megalocells and small nerve cell nuclei were also infected in the preoptic area, thalamus, medulla oblongata and spinal cord. Only a few small nerve cells were infected in the olfactory bulb and optic tectum. The retina of some diseased fish displayed vacuolated bipolar cells of the inner nuclear layer and in the ganglion cell layer. These SGNNV-infected nerve cells displayed viroplasmic inclusions containing virions, vacuoles and myelin-like structures. Based on observed histopathological changes, the lesion of the CNS was characterized by encephalitis but not encephalopathy.

High expression of interleukin-1beta in the corneal epithelium of MRL/lpr mice is under the control of their genetic background

MRL/Mp mice bearing the Fas deletion mutant gene, lpr (MRL/lpr), spontaneously develop polyarthritis, sialoadenitis and dacryoadenitis, resembling rheumatoid arthritis (RA), and also corneal involvement such as keratopathy and scleritis, which is a major complication in RA patients. In this study, we found that the expression levels of IL-1beta and MMP-1 mRNAs in cornea were high in both MRL/lpr and MRL/Mp-+/+ strains of mice at an age younger than when they develop any inflammatory lesions. This was not true of other inbred strains, even those bearing the lpr gene, and also not of (NZB x NZW) F1 lupus mice. There was no significant difference in the expression of IL-1alpha and TGFbeta in cornea in these strains. Using crosses between MRL/lpr and C3H/HeJ-lpr/lpr (C3H/lpr) mice, at least the expression of IL-1beta was found to be under the control of the MRL genetic background, likely with a recessive mode of inheritance. Considering that IL-1beta in cornea was detected particularly in the epithelial layer, the high expression of IL-1beta in cornea is most likely involved in the genetic predisposition for corneal involvement and possibly also for arthritis in an MRL strain of mice.

An anatomical study of the ligaments of the ulnar compartment of the wrist

The ligamentous structures of the triangular fibrocartilage complex (TFCC) and their attachments were examined anatomically and histologically using fresh and embalmed cadavers. The TFCC was observed to have a three-dimensional structure consisting of three palmar ligaments--the short radiolunate (SRL), ulnolunate (UL), and ulnotriquetral (UT) ligaments. In addition, the attachment site of the ulnocarpal ligament (UC), which had been previously unknown, was identified. The dorsal components of the TFCC have been previously reported to consist solely of the extensor carpi ulnaris (ECU) subsheath; however, the ligamentous components running from the ulnar styloid process to the triquetrum were found at a layer deeper than the floor of the ECU subsheath. The UC has been reported previously as a two-dimensional structure, but there has been some disagreement as to its attachment sites.(2-6,14,15) It is suggested that the dorsal UT ligament should be considered as a separate ligament, based on its different direction and distal attachment site as compared with those of the ulnar collateral ligament (UCL) and ECU subsheath.

Acute haemodynamic benefits of biatrial atrioventricular sequential pacing: comparison with single atrial atrioventricular sequential pacing

OBJECTIVE

To evaluate the acute effects on haemodynamic variables of biatrial pacing in comparison with high right atrial (HRA) pacing and left lateral atrial pacing.

PATIENTS AND DESIGN

23 patients were paced from the HRA site, the lateral site of the coronary sinus (CS), and both sites on two fixed atrioventricular delays (100 and 150 ms) during atrioventricular sequential pacing at 80 and 100 beats/min in random order.

MAIN OUTCOME MEASURES

After five minute pacing, the maximum P wave duration on a 12 lead ECG, cardiac output, pulmonary capillary wedge pressure, and the transmitral flow pattern by transthoracic echocardiography were measured.

RESULTS

Biatrial pacing delivered the shortest P wave duration (133 (25) ms, 133 (27) ms, and 96 (15) ms during HRA, CS, and biatrial pacing, respectively; p < 0.001), and the most improvement in cardiac output and pulmonary capillary wedge pressure (3.71 (0.93) l/min and 15 (7) mm Hg, 3.79 (0.97) l/min, and 14 (6) mm Hg, and 4.09 (1.01) l/min and 13(6) mm Hg during HRA, CS, and biatrial pacing, respectively; p < 0.01). Biatrial pacing most significantly decreased the intervals between the atrial pacing spike and the peak and end of the atrial filling wave (186 (16) ms and 250 (22) ms, 172 (19) ms and 242 (24) ms, and 153 (15) ms and 227 (23) ms during HRA, CS, and biatrial pacing, respectively; p < 0.001). It also significantly increased the mitral flow time velocity integral and peak atrial filling wave velocity (7.5 (3.4) cm and 63.8 (17.6) cm/s, 7.8 (3.0) cm and 62.4 (16.6) cm/s, and 8.3 (3.4) cm and 67.8 (19.3) cm/s during HRA, CS, and biatrial pacing, respectively; p < 0.05). The improvements in haemodynamic variables were especially remarkable in patients who had a longer interatrial conduction delay.

CONCLUSIONS

Biatrial pacing yielded the most significant improvements in haemodynamic variables. These haemodynamic benefits may play a part in reducing intra-atrial pressure and preventing atrial fibrillation.

Effect of extracorporeal shock waves on callus formation during bone lengthening

The effects of extracorporeal shock waves (ESWs) on callus formation during bone lengthening were studied in 25 female Japanese white rabbits. Bone lengthening of 9.8 mm was obtained over 2 weeks using the Orthofix M-100 bone fixator. ESWs were applied 3 weeks after surgery. Pins were removed 7 weeks after surgery, and specimens were prepared after the animals were killed at 9 and 24 weeks. The shock wave setting used was 0.42 mJ/mm(2) with a pulse interval of 2 Hz; 3000 shots each were applied to the central and peripheral areas. The specimens were evaluated using radiography, bone mineral density (BMD) measured by dual energy absorptiometry (DXA), and a three-point bending test to evaluate mechanical strength. Histological examination was performed on the lengthened portion. Radiographs and histological observations revealed no apparent fractures in nonlengthening tibias at the shock wave energy densities used. Radiographic observations revealed no apparent differences between the control group and the ESW group. BMD measurements by DXA revealed significantly increased bone mass in the ESW group 9 weeks after surgery. At 24 weeks after surgery the mean BMD had decreased to 25% and 15% of the values at 9 weeks in the control and ESW groups, respectively. The three-point bending test revealed no significant differences between the groups. Histological observations revealed significant capillary formation and osteoblasts and chondrocytes in the bone marrow as well as bridging of newly formed trabeculae 2 weeks after the bone was lengthened. At 4 weeks after treatment, observations included parts of the lengthened portion with no cortex or immature bone. At 9 weeks after surgery, cortex formation and a normal medullary cavity were clearly observed in the control group, whereas observations in the treated group included areas of the lengthened portion with no cortex and formation of immature trabecular structures and increased cancellous bone in the center of the lengthened portion. At 24 weeks after surgery, more prominent cortex formation and fatty marrow were observed in the ESW group than in the control group.

Hepatic induction of mitochondrial and cytosolic acyl-coenzyme a hydrolases/thioesterases in rats under conditions of diabetes and fasting

Acyl-coenzyme A (CoA) hydrolases/thioesterases are a group of enzymes that catalyze the hydrolysis of acyl-CoA thioesters to free fatty acids and CoA-SH. The potency of these enzymes may serve to modulate intracellular concentrations of acyl-CoAs, free fatty acids, and CoA to affect various cellular functions, including lipid metabolism. In this study, we investigated the effect of diabetes and fasting on the protein levels of mitochondrial (MTE-I) and cytosolic acyl-CoA thioesterases (CTE-I), multigene family members of this class of enzymes, in adult rat liver. Rats were treated with alloxan to induce diabetes or fasted for 72 hours. Western blot analysis with the liver homogenates revealed 2.8-fold and 3.8-fold increases in MTE-I and 8.5-fold and 9.2-fold increases in CTE-I under the diabetic and fasting conditions, respectively, compared with the control in which the level of MTE-I was 4.3-fold higher than CTE-I. Serum level of free fatty acids was elevated 5-fold and 2.5-fold in diabetic and fasted rats, respectively. These results confirm the adaptive induction of MTE-I and CTE-I in response to fatty acid overload in the liver, being consistent with their auxiliary role in fatty acid degradation.

Fluorescence microscopic visualization of a DNA-cationic fullerene complex

Cationic fullerene derivative 1, which is soluble in aqueous medium, bound to double stranded DNA. Observation of Coliphage T4 DNA in the absence and presence of 1 by fluorescence microscopy suggested that 1 bound to DNA along its groove. Upon irradiation of visible light on the DNA complex of 1, DNA was cleaved dramatically. The process of DNA photo-cleavage could be monitored continuously by fluorescence microscopy.

Novel synthesis of a tetra-acridinyl peptide as a new DNA polyintercalator

Tetra-acridinyl peptide 2 was synthesized from Fmoc-Lys(Boc)-OH and Fmoc-Lys(Acr)-OH (1) with the peptide synthesizer. The CD measurement suggested that 2 forms a special organized structure by itself in buffered solution. Peptide 2 binds to double stranded DNA with a very large affinity constant, which is 10(3)-times larger than that of quinacrine. Spectrophotometric and hydrodynamic studies suggested that all of the acridinyl parts of 2 contribute to the intercalating interaction for the DNA binding. Our finding in this experiment demonstrates that polyintercalators such as 2 can be assembled quickly by the automated synthesizer.

Ferroceneacetyl naphthalene diimide as a new electrochemical ligand for DNA sensing

New electrochemically active DNA ligand 1 was synthesized by the connection of ferroceneacetic acid at the terminal amino moieties of two imide substituents of naphthalene diimide. Electrochemical experiments in aqueous solution containing DMSO showed that the selectivity for double stranded DNA of 1 has increased from that of ligand 2 previously reported. The peak current of 1 shifted toward the negative side from that of 2, thereby shortening the time required for gene detection.

Implication of brain-derived neurotrophic factor in the release of dopamine and dopamine-related behaviors induced by methamphetamine

It is widely recognized that methamphetamine enhances the release of dopamine at dopaminergic neuron terminals of the mesolimbic system, which induces dopamine-related behaviors. Brain-derived neurotrophic factor (BDNF), a neurotrophin, binds to and activates its specific receptor tyrosine kinase, TrkB. BDNF has been shown to influence the release of dopamine in the mesolimbic dopamine system. The present study was designed to investigate roles of BDNF and TrkB in the expression of methamphetamine-induced dopamine release in the nucleus accumbens and dopamine-related behaviors induced by methamphetamine in rats. Methamphetamine (1 mg/kg, s.c.) produced a substantial increase in the extracellular levels of dopamine and induced a progressive augmentation of dopamine-related behaviors such as rearing and sniffing. In contrast, both the stimulation of dopamine release and induction of dopamine-related behaviors by methamphetamine were significantly suppressed by pretreatment with intra-nucleus accumbens injection of either BDNF (2.0 microl/rat, 1:1000, 1:300 and 1:100) or TrkB (2.0 microl/rat, 1:1000 and 1:100) antibody. Furthermore, the basal level of dopamine in the nucleus accumbens was not affected by treatment with both BDNF and TrkB antibodies. These findings provide further evidence that BDNF/TrkB pathway is implicated in the methamphetamine-induced release of dopamine and the induction of dopamine-related behaviors.

Linker chain effect of ferrocenyl naphthalene diimide on a double stranded DNA preference

Naphthalene diimide derivative 1 carrying two 3-(ferrocenyl-methylamino)-propyl substituents was synthesized as a new hybrid indicator for electrochemical gene sensing. Ligand 1 showed a preference for double stranded DNA four-times larger than 2 previously described. The peak potential of 1 shifted 30 mV toward the negative side from that of 2, thereby shortening the time required for gene detection.

Detection of DNA hybridization by use of a lanthanide fluorescent intercalator that specifically binds to double stranded DNA

Toward development of a DNA microarray system in which neither labeling nor amplification of the nucleic acids from living cell is required, we have developed a new method for the detection and quantification of target DNA hybridized with probe DNA fixed on a solid surface. This method utilizes a fluorescent intercalator: naphthalene diimide derivative carrying two fluorescent tetradentate beta-diketone-Eu3+ chelates. This compound selectively binds to double stranded DNA (dsDNA) fixed on a plastic assay plate. The amount of the compound bound to single stranded DNA (ssDNA) is negligible. The fluorescent intensity of Eu3+ was in proportion to the amount of the fixed DNA, showing that the compound quantitatively binds to dsDNA. Therefore, this method can be used not only to detect dsDNA, but also to measure the amount of DNA on a solid surface.

DNA binding behavior of peptides carrying acridinyl units: First example of effective poly-intercalation

Bis-, tris-, tetrakis-, and pentakis-acridinyl (Acr) peptides 2-5 were synthesized from Fomc-Lys(Acr)-OH and Fmoc-Lys(Boc)-OH with the peptide synthesizer. The molar absorptivity of these peptides saturated with an increase in the number of the acridinyl unit in the peptide, suggesting intramolecular stacking of the acridinyl units. It was found from Scatchard analysis by means of spectrophotometry that all the peptides can bind to double stranded DNA with very high affinity even under high salt conditions (0.4 M NaCl) and the logarithmic binding constant increased in proportion to the number of the acridinyl unit in the peptide. This result suggested effective poly-intercalation of all the acridinyl units into double stranded DNA.

Establishment and Characterization of a Human Ovarian Granulosa Tumor Cell line (HSOGT)

We successfully established a novel ovarian granulosa tumor cell line (HSOGT). The tumor tissue of the ovary was derived from a 25 year-old Japanese woman under her consent. The cell line was maintained for over 14 months, subcultured more than 73 times, and had a population doubling time of 18.9 hours. Phase contrast microscopy displayed a pavement-like arrangement without contact inhibition. The chromosome number showed a wide distribution of aneuploidy and the mode was 83; many marker chromosomes were observed. The HSOGT was also successfully xenotransplanted into nude mice. The cell line produced estradiol and has preserved some characters of granulosa cells with stable growth in vitro. We firmly believe that this cell line will be a most useful tool for endocrinological investigation of human granulosa cells.

Real time quantification of low temperature radiofrequency ablation lesion size using phased array intracardiac echocardiography in the canine model: comparison of two dimensional images with pathological lesion characteristics

OBJECTIVE

To evaluate the feasibility of quantifying low temperature radiofrequency catheter ablation (RFCA) lesions using a phased array intracardiac echocardiography (ICE) catheter--with better tissue penetration and in a deflectable device-in the canine model.

INTERVENTION

Low temperature radiofrequency (RF) energy (50-60 degrees C at up to 40 W) was delivered to the left ventricle in 11 beagles for 60 seconds, using an 8 French catheter with a deflectable tip and a 4 mm distal electrode.

MAIN OUTCOME MEASURES

Comparison of the width and depth of RFCA lesions measured by ICE with pathological findings.

RESULTS

33 RF energies were delivered in 11 dogs. 31 lesions (94%) were confirmed at necropsy. 27 of 31 ablation lesions (87%) were detected by ICE. The mean (SD) width and depth of the ICE detected lesions were 10.4 (2.6) mm and 5.7 (1.9) mm, respectively. Pathological findings showed that RFCA lesions consisted of inner and outer layers. Macroscopically, the mean (SD) width and depth of the inner layers were 7.6 (2.3) mm and 3.6 (1.2) mm and those for the whole layers were 10.0 (2.8) mm and 5.3 (1.5) mm, respectively. Microscopically, the inner and outer layers corresponded to necrotic and oedematous areas, respectively. The ICE detected lesion size had better correlation with the pathological measurements of the whole layers in width (r = 0.911) and in depth (r = 0.756).

CONCLUSION

The real time evaluation of RFCA lesion size using the phased array ICE is feasible, even with a low temperature RF application. However, ICE slightly overestimates RFCA lesion size compared with pathological necrotic lesion size.

3D culture of murine hematopoietic cells with spatial development of stromal cells in nonwoven fabrics

BACKGROUND

The in vivo hematopoietic microenvironment is composed of stromal cells and extracellular matrix in a 3D configuration. We have created a 3D microenvironment in vitro, employing spatial development of stromal cells in a nonwoven fabric porous carrier, Fibra-cel (FC). We compared its performance with that of a 2D microenvironment.

METHODS

Primary murine BM cells were inoculated on the layers of stromal cells prepared in FC (3D) or on a dish (2D) and cultured for 7-21 days. The hematopoietic cells harvested from the cultures were evaluated by colony-forming unit (CFU) assay and transplantation to sub lethally irradiated mice.

RESULTS

The maximum stromal cell concentration in the 2D culture was higher than that in the 3D culture. However, the hematopoietic cell concentration in the 3D culture was kept at a higher level than that in the 2D culture. The number of CFU-mix increased five times during 3D cultivation, but decreased in the 2D culture. The engraftment percentage of 3D cultured cells was comparable with that of fresh cells, and markedly higher than that of 2D cultured cells.

DISCUSSION

The 3D culture constructed with FC and stromal cells was clearly superior to 2D culture because hematopoietic progenitor cells were expanded without the addition of cytokines and the content of hematopoietic stem cells was maintained.

Cementifying fibroma in the ethmoidal sinus extending to the anterior cranial base in an 11-year-old girl: a case report

A case of an 11-year-old female with cementifying fibroma in the ethmoidal sinus extending to the anterior cranial base was presented. She complained of slowly progressive nasal obstruction and anosmia. Magnetic resonance imaging (MRI) revealed a tumor in both ethmoidal and sphenoidal sinuses and nasal cavity. Although a tumor reduction surgery was attempted through a transnasal approach, tumor size increased gradually and right exophthalmos subsequently appeared. The pathological diagnosis was cementifying fibroma of the nose. Total tumor removal was consequently accomplished through the intracranial anterior transbasal approach. The surgical approach should be selected according to the site and expansion of the lesion in individual patients.

Abnormal response to sodium channel blockers in patients with Brugada syndrome: augmented localised wall motion abnormalities in the right ventricular outflow tract region detected by electron beam computed tomography

OBJECTIVE

To investigate the relation between the wall motion abnormalities and sodium channel abnormalities in cases of the Brugada syndrome.

DESIGN

Consecutive prospective case-control study in a single hospital.

SETTING

Tertiary referral centre.

PATIENTS

13 consecutive patients with Brugada syndrome and 13 age and sex matched control subjects.

INTERVENTIONS

Each subject underwent electron beam computed tomography (EBT) and a 12 lead ECG before and after disopyramide injection.

MAIN OUTCOME MEASURES

QRS width and the magnitude of ST segment elevation in the 12 lead ECG; wall motion by EBT.

RESULTS

After disopyramide, EBT revealed deterioration of focal wall motion abnormalities in the right ventricular outflow tract region in eight of the 13 patients (62%). Prolongation of the QRS width after disopyramide injection in lead V2, which usually reflects the electrical activity in right ventricular outflow tract region, was greater in these eight patients (p < 0.01) than in the other five patients, in whom wall motion did not change after disopyramide. The degree of augmentation of ST segment elevation did not differ significantly between the two groups

CONCLUSIONS

The deterioration of wall motion abnormalities in the right ventricular outflow tract region after disopyramide suggests the presence of functional abnormalities of the sodium channel. Some patients with Brugada syndrome may have arrhythmogenic substrates with abnormal responses to sodium channel blockers.

Osteoid osteoma in the mandible

A case of osteoid osteoma (OO) in the mandible of 26-year-old female is presented. Her main complaint was intermittent pain during a 3 year period. The panoramic radiograph of the mandible showed diffuse sclerosis including an ill-defined circular radiopacity in the molar region. Computed tomography (CT) revealed an osseous lesion of 10 mm diameter that was located in the cortical bone of the mandible. Bone scintigraphy showed a localized region of high uptake of 99mTc HMDP. The lesion was diagnosed as an OO by histopathological examination of the surgical specimen and CT findings. Since radiological appearance has very significant meaning in the differentiation of an OO from other bone forming tumors, CT is the method of choice when the main symptom is pain and the conventional radiography was not informative.

A laboratory and field evaluation of Macrocyclops distinctus, Megacyclops viridis and Mesocyclops pehpeiensis as control agents of the dengue vector Aedes albopictus in a peridomestic area in Nagasaki, Japan

The use of the cyclopoid copepods Macrocyclops distinctus (Richard) Megacyclops viridis (Jurine) and Mesocyclops pehpeiensis Hu (Cyclopoida: Cyclopidae) as biological control agents against the dengue vector Aedes albopictus (Skuse) (Diptera: Culicidae) was evaluated. In the laboratory their predatory ability was highest against the younger instars of Ae. albopictus and none of the three copepods killed the fourth instar. Except for M. viridis, predatory ability was affected by the size of the container: the smaller the container, the higher the predation. A 4-month field test was conducted to examine the impact of these predators on wild Ae. albopictus. Thirty artificial containers were placed in a peridomestic area to allow Ae. albopictus colonization. We showed continuous and similar oviposition responses in treated and control containers. The densities of Ae. albopictus showed considerable short-term changes and were much reduced by the copepod species. Macrocyclops and the mixture of all three provided better Ae. albopictus control than either Megacyclops or Mesocyclops alone. When larval densities peaked in the control containers in August and September, the overall reduction due to the copepods was nearly complete. Mesocyclops inoculated alone had the highest population survival. However, the growth and survival of all the copepod species was poor when the three genera were mixed. Based on their performance and survival in the trial, Macrocyclops and Mesocyclops merit consideration as bio-control agents of Ae. albopictus.

New applications of intracardiac echocardiography: assessment of coronary blood flow by colour and pulsed Doppler imaging in dogs

OBJECTIVE

To explore the application of a new 10 French intracardiac echocardiography (ICE) catheter with phased array and Doppler capable transducer for the assessment of epicardial and intramyocardial coronary blood flow.

METHODS

The coronary arteries were detected by cross sectional imaging in seven closed chest dogs, and coronary blood flow visualised by colour Doppler. Blood flow velocities were recorded by pulsed Doppler at baseline for reproducibility of repeated measurements, and during hyperaemia for coronary flow reserve measurements. Comparisons were made with Doppler guide wire data obtained simultaneously. Intramyocardial coronary artery blood flow was assessed by colour flow mapping, and the blood flow velocities recorded using pulsed Doppler at baseline and during hyperaemia.

RESULTS

Seven left main, six left anterior descending, seven left circumflex, and five right coronary arteries were visualised in the seven animals by cross sectional or colour Doppler imaging. Repeated measurements of coronary flow velocity showed a good correlation (mean diastolic velocity, r = 0.93, n = 22, p < 0.0001; peak diastolic velocity, r = 0.96, n = 22, p < 0.0001, respectively). Intraobserver/interobserver variability was satisfactorily low. Coronary flow reserve from ICE correlated highly with the value obtained from the Doppler guide wire (r = 0.90, n = 26, p < 0.0001). Intramyocardial coronary blood flow was identified in all seven dogs, and flow velocities were recorded at baseline and during hyperaemia in four animals.

CONCLUSIONS

This new ICE catheter provides high quality diagnostic resolution. It is useful for coronary blood flow assessment.

Selective recovery of founder genetic diversity in aquacultural broodstocks and captive, endangered fish populations

Hatchery broodstocks used for genetic conservation or aquaculture may represent their ancestral gene pools rather poorly. This is especially likely when the fish that found a broodstock are close relatives of each other. We re-analysed microsatellite data from a breeding experiment on red sea bream to demonstrate how lost genetic variation might be recovered when gene frequencies have been distorted by consanguineous founders in a hatchery. A minimal-kinship criterion based on a relatedness estimator was used to select subsets of breeders which represented the maximum number of founder lineages (i.e., carried the fewest identical copies of ancestral genes). UPGMA clustering of Nei's genetic distances grouped these selected subsets with the parental gene pool, rather than with the entire, highly 'drifted' offspring generation. The selected subsets also captured much of the expected heterozygosity and allelic diversity of the parental gene pool. Independent pedigree data on the same fish showed that the selected subsets had more contributing parents and more founder equivalents than random subsets of the same size. The estimated mean coancestry was lower in the selected subsets, meaning that inbreeding in subsequent generations would be lower if they were used as breeders. The procedure appears suitable for reducing the genetic distortion due to consanguineous and over-represented founders of a hatchery gene pool.

Enhanced exudation of fibrinogen into the perivascular space in acute inflammation triggered by neutrophil migration

OBJECTIVE

The present experiments were performed to ascertain whether or not all plasma components are extravasated when vascular permeability is increased.

ANIMALS

Male Sprague-Dawley strain rats (specific pathogen-free) 8 weeks old (for histamine exudation) or 9-10 weeks old (for carrageenin pleurisy) were used.

METHODS

Histamine or A-carrageenin was injected into the rat right pleural cavity to induce rat pleurisy. Protein components in the inflammatory exudate and plasma were separated by high performance liquid chromatography. Coagulation time was assessed, and the fibrinogen levels in the pleural exudate were determined by thrombin time. The fibrinogen levels were also visualized by immunoblot analysis. Tumor necrosis factor-alpha (TNF-alpha, 0.4 microg/rat, intrapleurally), anti-rat CD18 monoclonal antibody (anti-CD18 antibody, 1 mg/kg, i. v.) and granulocyte-colony stimulating factor (G-CSF, 100 microg/kg, s.c. twice daily for 4 days) were used.

RESULTS

In the histamine-induced extravasation, the level of plasma protein components with large molecules over 900 kD in the exudate was 62% of that in the rat's own plasma. The amount of fibrinogen in the pleural exudate was 1/8 of that in the plasma and was faintly detected in immunoblot analysis, but it was clearly detected after the treatment of rats with TNF-alpha. In rat carrageenin pleurisy, fibrinogen was hardly detected in immunoblot analysis in the exudate collected 0.5 h after carrageenin, when neutrophils did not migrate into the exudate. However, it was clearly present after neutrophil migration started 2 h later The increase in the neutrophil counts in the exudate caused by G-CSF enhanced the fibrinogen level in the exudate, whereas intravenous injection of anti-CD18 antibody suppressed the fibrinogen level in immunoblot analysis.

CONCLUSIONS

Venular permeability increase in the rat histamine exudation induced minimal extravasation of plasma proteins with large molecules, such as fibrinogen, while fibrinogen molecule was detected in rat carrageenin-injected pleurisy, when neutrophil diapedesis occurred. Thus, only when neutrophils started to migrate into the perivascular space was fibrinogen clearly detected in the exudate.

Intramedullary anchoring strength of titanium rod with mixed beta-tricalcium phosphate and fibrin adhesive

Histological and biomechanical studies were conducted in Japanese white rabbits to evaluate the effect of mixed beta-tricalcium phosphate (beta-TCP) and fibrin adhesive on bone formation around a titanium rod in femoral bone marrow. The animals received injections of fibrin adhesive with beta-TCP or hydroxyapatite into the femoral bone marrow from the distal end of the femur, where a titanium rod was inserted. Group I received fibrin adhesive only, group II received fibrin adhesive and hydroxyapatite (HA), and group III received fibrin adhesive and beta-TCP. On the examination of nondecalcified specimens, group III showed cross-bridging bone formation between beta-TCP particles at week 8, this being observed earlier than in group II. On mechanical evaluation, group III showed significant differences in maximum pull-out force at week 8, and in modulus of rigidity at week 24, compared with the other groups. On the examination of decalcified specimens, chronic inflammation was clearly identified in group I at week 8, and residual beta-TCP particles were found in group III at week 24. These results suggest that the mixture given to group III filled bone defects around the rod and promoted bone formation at a relatively early stage. Inflammation and delayed absorption of beta-TCP, which appeared to be a reaction of heterologous fibrins, caused delays in bone formation promoted by beta-TCP. Nevertheless, the use of fibrin adhesive appears to be a feasible method for loading powdered beta-TCP.

Bovine retained placenta: hormonal concentrations in fetal and maternal placenta

The aim of this study was to evaluate the relationship between the occurrence of retention of the fetal membranes (RFM) and the hormonal concentrations of progesterone, estradiol-17beta, prostaglandin E(2) (PGE(2)), prostaglandin F(2alpha) (PGF(2alpha)), oxytocin (OT), oxytocin receptor (OT-R), endothelin-1 and angiotensin II (Ang II) in the placental tissues of cattle. Parturition was induced in nine Holstein cows by a single injection of PGF(2alpha) on Day 274 of gestation. Six out of nine cows in the induced group did not release the fetal membranes within 12 h after parturition and served as the RFM group, and the remaining three cows in that group, which released their fetal membranes within 12 h, served as the non-RFM group. Five other cows calved spontaneously and served as controls. The placental tissues were collected immediately (0 h) and at 6 h after parturition. The hormonal concentrations were measured by enzyme immunoassay in maternal and fetal placental tissues from RFM, non-RFM and control cows. There were no differences in P4 and E2 concentrations among the RFM, non-RFM and control groups. The mean PGF(2alpha) concentration of the RFM group was lower than those of the non-RFM and control groups in the maternal part of the placenta. In maternal tissues, the OT and OT-R concentrations in the RFM group were lower than those at 0 and 6 h after parturition in the non-RFM group. Additionally, the Ang II concentration of the RFM group in both the maternal and fetal parts of placental tissues tended to be higher than those of the other groups. In conclusion, the present results suggest that ET-1 and Ang II may play differential tissue-specific roles in the placental unit that may amplify the local endocrinological cascade involving OT, OT-R and PGF(2alpha) interactions which are necessary for normal placental separation in the cow.