Time-lapse microcinematography of osteocytes

We succeeded in the isolation of osteocytes from parietal bones of 16-day-old chick embryos. Isolated osteocytes showed a typical stellate morphology. More than 95% of these cells reacted with the osteocyte-specific antibody OB 7.3. In culture osteocytes formed gap junctions with each other, as could be established by ACAS. Sixteen-millimeter time-lapse microcinematography of the cells also demonstrated the formation of intercellular connections and gap junctions, and portrayed the interaction between osteocytes and osteoclasts: osteocytes seemed to inhibit osteoclast activity. This cinematography also showed the ability of osteocytes to proliferate after they had been disconnected from each other. Thereafter these cells redifferentiated into osteoblasts that became embedded in bone matrix produced by themselves. These findings suggest that osteocytes might be involved in bone formation during remodeling.

Intra-amniotic maternal hemorrhage in preterm labor: a case report

A primigravid women was transferred to hospital because of preterm labor at 32 weeks' gestation with no vaginal bleeding. Hematologic studies showed severe anemia. Ultrasound examination revealed polyhydramnios and a clot around the umbilical cord without retroplacental hematoma. Diagnostic amniocentesis revealed heavily blood stained fluid, but HbF was not detected. With a clinical diagnosis of intra-amniotic maternal hemorrhage, immediate cesarean section was performed. The mechanism of intra-amniotic maternal hemorrhage is discussed.

Improvement of fusing ability of human sperm to zona-free hamster eggs by conditioned media

A conditioned medium (CM) was prepared by culturing human sperm at 3.0 x 10(6) sperm/ml for 12 h. The fusion index increased significantly when the sperm penetration assay (SPA) was performed with CM (0.6 without CM to 2.0 with CM). The conditioned medium was also effective on the sperm from 11 patients who showed a low or zero value in SPA and who's in vitro fertilization treatment failed. When CM from the sperm of healthy donors was added to these patients' sperm, the fusing ability to zona free hamster eggs was significantly restored.

Non-invasive monitoring of tissue response to radiotherapy by localised proton spin-lattice relaxation time in mice

Proton spin-lattice relaxation time T1 of the localised tumour portion and its neighbouring portion of tumour-bearing mice legs is successively observed before and after radiotherapy by applying the previously proposed magnetic focusing method. Changes in T1 values are also compared with the histological radiation effects. For un-irradiated tumours, T1 increases gradually with tumour growth. T1 of the tumour portion shows significant decrease after radiotherapy. The decrease in the T1 values of the tumour clearly depends on the single radiation dose of 30, 45 and 60 Gy, respectively. A rapid decrease in the T1 values of the tumour occurs prior to the decrease in tumour volume. These decreases in the T1 values of the tumour after radiotherapy correspond positively to the increase of the histological radiation effects. After the reduction in the T1 values of the irradiated tumour portion, a successive increase in T1 values is observed and suggests local recurrence of the tumour. These results show that localised T1 relaxation time is a good reflection of the tissue response to radiotherapy.

Molecular biology of proteasomes

Eukaryotic proteasomes are unusually large proteins with a heterogeneous subunit composition and have been classified into two isoforms with apparently distinct sedimentation coefficients of 20S and 26S. The 20S proteasome is composed of a set of small subunits with molecular masses of 21-32 kDa. The 26S proteasome is a multi-molecular assembly, consisting of a central 20S proteasome and two terminal subsets of multiple subunits of 28-112 kDa attached to the central part in opposite orientations. The primary structures of all the subunits of mammalian and yeast 20S proteasomes have been deduced from the nucleotide sequences of cDNAs or genes isolated by recombinant DNA techniques. These genes constitute a unique multi-gene family encoding homologous polypeptides that have been conserved during evolution. In contrast, little is yet known about the terminal structures of the 26S proteasome, but the cDNA clonings of those of humans are currently in progress. In this review, I summarize available information of the structural features on eukaryotic 20S and 26S proteasomes which has been clarified by molecular-biological methods.

[Surgical treatment of infective endocarditis: application of DNA probe method]

DNA probe method is a new bacteriological method for diagnosis of bacteria. The authors tried to apply the method to diagnosis of bacteremia and treatment of infective endocarditis. We could diagnose the patient's illness as bacteremia with this method even when blood cultures are not positive. We suggest that cardiac surgery should be performed in case bacteria is detected repeatedly with DNA probe method. Therefore it is useful for decision whether cardiac surgery for patients with active infective endocarditis should be done or not.

A clinicopathologic study of 30 patients with Paget's disease of the vulva

Clinical and pathologic analyses were performed in 30 patients with Paget's disease of the vulva to investigate the risk factors for recurrence. From 1971 to 1993, we carried out histologic examinations in 27 resected vulvae to detect Paget's cells at the surgical margin. Prior to 1981, 9 patients underwent the examination, and 6 of them had positive surgical margins, and 2 of these 6 patients had local recurrence. After 1982, the preoperative multiple biopsy and intraoperative frozen section diagnosis of the surgical margins were performed, and as a result, cases of the lesions remaining as stumps on the vaginal side decreased in 7 of 18 examined patients. In these 7 cases, 2 cases had local recurrence. The patients were further divided into three groups according to histologic findings to investigate their prognosis: 10 patients with intraepithelial Paget's disease (IEP), 9 patients with minimally invasive Paget's disease (MIP), and 11 patients with underlying carcinoma (UC) including 2 cases of carcinoma in situ. Four locally recurrent cases were found in IEP or MIP, and the longest period from surgery to recurrence was 8 years and 4 months. The invasive UC lesions persisted or recurred shortly after surgery (median, 10 months) and 5 of the 6 patients with general metastasis. For IEP and MIP, surgical margins of the vaginal side should be carefully examined with preoperative multiple biopsy and intraoperative frozen section, and also a long-term follow-up is necessary. With regard to invasive UC patients, their prognosis was found to be very poor for general metastasis.

Roles of proteasomes in cell growth

Proteasomes are large, unique protein complexes catalyzing energy- and ubiquitin-dependent proteolysis. Recent studies have revealed that these complexes are involved in two important cellular functions. One is to make antigen fragments for major histo-compatibility complex (MHC) class I-restricted antigen presentation and the other is to regulate the cell cycle by proteolysis. Here we review only the latter function of proteasomes. Proteasomes are widely distributed in eukaryotic cells, but their levels have been shown to be particularly high in various immature cells, such as cancerous, fetal and lymphoblastic cells, and agents including cell differentiation were found to suppress their expression. These conditions also regulate the expression of ubiquitin genes in a similar way, suggesting that proteasomes act ubiquitin-dependently in their 26S form in immature cells. High levels of proteasomes were found immunochemically in the nuclei of rapidly growing cells, indicating that proteasomes are important for eukaryotic cell growth. Indeed, gene disruptions of most subunits of proteasomes in yeast resulted in total suppression of cell growth and cell death. Short-lived regulatory factors of the cell cycle, such as Fos, p53, Mos, and cyclins are degraded by the proteasome-ubiquitin pathway under phosphorylated or dephosphorylated conditions. Ornithine decarboxylase, which is also a short-lived enzyme and is involved in the early phase of cell growth, is quickly degraded by proteasomes with antizyme, but without ubiquitination. Recently, we found that one of the regulatory factors of 26S proteasomes, p31, is a homologue of Nin1p, whose mutation caused inhibition of the cell cycle in yeast. These results indicate that proteasomes play important roles in regulation of the cell cycle in eukaryotes.

Late massive hemorrhage following cystogastrostomy for pancreatic pseudocyst: report of a case

We report the case of a man who developed life-threatening massive gastric hemorrhage 3 months after undergoing cystogastrostomy for a pancreatic pseudocyst. After cystogastrostomy, the pancreatic pseudocyst became remarkably reduced in size, having the appearance of a shallow ulcer by barium study. However, tarry stools and hematemesis developed 3 months later, 6 days after which sudden massive hematemesis and melena occurred with severe hypotension. At emergency operation, a large artery at the bottom of the reduced cyst wall was found to have ruptured and hemostasis was achieved by suture ligation. The splenic artery was suspected as the bleeding point because a 95% abrupt stenosis was seen on angiography-performed the next day. Thus, the risk of hemorrhage occurring after internal drainage of a pancreatic pseudocyst even in the late postoperative period should always be borne in mind.

Cytokeratin fragment 21-1 in gynecologic malignancy: comparison with cancer antigen 125 and squamous cell carcinoma-related antigen

We measured serum cytokeratin fragment 21-1 (CYFRA 21-1) levels by a solid-phase immunoradiometric assay in 102 healthy Japanese women, and set the reference value at 1.9 ng/ml (mean +2 SD of the serum levels based on a linear distribution). Pretreatment serum CYFRA 21-1 levels were also analyzed in 235 women with benign (n = 94) or malignant (n = 141) gynecologic disease, and were compared with the serum levels of CA 125 and SCC. The respective positivity rates for CYFRA 21-1 and CA 125 were 64.0 and 77.2% in ovarian malignancy, while they were 4.2 and 30.8% in benign ovarian masses. CYFRA 21-1 had an accuracy of 61.3% in diagnosing ovarian malignancy, which was higher than that of CA 125 (53.4%). The positive predictive value of CYFRA 21-1 for ovarian malignancy reached 94.1%, which was significantly (p < 0.005) higher than that of CA 125 (68.8%). These findings indicate the potential usefulness of CYFRA 21-1 as a tumor marker for ovarian malignancy. In addition, the positivity rates fo CYFRA 21-1 in cervical cancer (51.2%) and endometrial cancer (52.2%) were also similar to the respective rates for SCC and CA 125, which suggests that CYFRA 21-1 seems to be a general tumor marker for gynecologic malignancy.

Metabolism of a new local anesthetic, ropivacaine, by human hepatic cytochrome P450

BACKGROUND

Ropivacaine is a local anesthetic with a long duration of action. Although it is less toxic than bupivacaine, local anesthetic toxicity is possible when the plasma concentration is increased. Because ropivacaine is an amide-type local anesthetic, it is metabolized by cytochrome P450 (P450) in the liver, and its elimination and plasma concentration can be dependent on the level of P450. The purpose of this investigation was to elucidate the metabolism of ropivacaine by human hepatic P450.

METHODS

The metabolism of ropivacaine was compared using recombinant human and purified rat hepatic P450 isozymes. An inhibition study using antibodies against rat P450 was performed using hepatic microsomes from human and rat to identify which P450s are involved in ropivacaine metabolism.

RESULTS

Ropivacaine was metabolized to 2',6'-pipecoloxylidide (PPX), 3'-hydroxyropivacaine (3'-OH Rop), and 4'-hydroxyropivacaine (4'-OH Rop) by hepatic microsomes from human and rat. PPX was a major metabolite of both human and rat hepatic microsomes. In a reconstituted system with rat P450. PPX was produced by CYP2C11 and 3A2, 4'-OH Rop by CYP1A2, and 3'-OH Rop by CYP1A2 and 2D1. Formation of PPX in rat hepatic microsomes was inhibited by anti CYP3A2, but not by CYP2C11 antibody, and formation of 3'-OH Rop was inhibited by CYP1A2 and 2D1 antibodies. Anti CYP3A2 and 1A2 antibodies inhibited the formation of PPX and 3'-OH Rop in human hepatic microsomes, respectively. Recombinant human P450s expressed in lymphoblast cells were used for further study. CYP3A4 and 1A2 formed the most PPX and 3'-OH Rop, respectively. Ropivacaine N-dealkylation and 3'-hydroxylation activities correlated well with the level of CYP3A4 and 1A2 in human hepatic microsomes, respectively.

CONCLUSIONS

Ropivacaine was metabolized to PPX, 3'-OH Rop, and 4'-OH Rop by hepatic P450. PPX was a major metabolite in human hepatic microsomes. CYP3A4 was involved in producing PPX. CYP1A2 was involved in the formation of 3'-OH Rop in human hepatic microsomes.

Identification and molecular analysis of Lactococcus lactis rpoD operon

The complete nucleotide sequence of an open reading frame (ORF) preceding the Lactococcus lactis rpoD gene is reported. It was suggested that this ORF encodes Lactococcus lactis DNA primase and that the L. lactis rpoD operon consists of only two genes. Northern hybridization analysis showed that i) there are four mRNAs transcribing the rpoD gene (from upstream, M1-M4), ii) only the 3.7-kb transcript M1 includes the entire rpoD operon, iii) the shortest transcript M4 exists at both logarithmic and stationary phases of growth while the other three transcripts appear only at logarithmic phase, and iv) no apparent induction at the transcriptional level but transient repression of M1 was found when the growth temperature was shifted from 30 degrees C to 42 degrees C. 5'-ends of all four mRNAs were identified by primer extension analyses.

Effect of real-time weighted integration system for rapid calculation of functional images in clinical positron emission tomography

A system has been developed to rapidly calculate images of parametric rate constants, without acquiring dynamic frame data for clinical positron emission tomography (PET). This method is based on the weighted-integration algorithms for the two- and three-compartment models, and hardware developments (real-time operation and a large cache memory system) in a PET scanner, Headtome-IV, which enables the acquisition of multiple sinograms with independent weight integration functions. Following the administration of the radiotracer, the scan is initiated to collect multiple time-weighted, integrated sinograms with three different weight functions. These sinograms are reconstructed and the images, with the arterial blood data, are inserted into the operational equations to provide parametric rate constant images. The implementation of this method has been checked in H(2)(15 )O and (18)F-fluorophenylalanine ((18)FPhe) studies based on a two-compartment model, and in a (18)F-fluorodeoxyglucose ((18)FDG) study based on the three-compartment model. A volunteer study, completed for each compound, yielded results consistent with those produced by existing nonlinear fitting methods. Thus, this system has been developed capable of generating rapidly quantitative, physiological images, without dynamic data acquisition, which will be of great advantage to PET in the clinical environment. This system would also be of great advantage in the new generation high-resolution PET tomography, which acquire data in a 3-D, septaless mode.

Pulmonary vascular involvement in neoplastic angioendotheliosis

Neoplastic angioendotheliosis has rarely been described as a respiratory disease. A patient is described with pulmonary vascular involvement induced by neoplastic angioendotheliosis in pulmonary vessels.

(1-->3)-beta-D-glucan in culture fluid of fungi activates factor G, a limulus coagulation factor

Two well-known polysaccharides, (1-->3)-beta-D-glucan and mannan, are major structural components of the fungus cell wall. The G test is a direct method to measure (1-->3)-beta-D-glucan using a (1-->3)-beta-D-glucan-sensitive component, factor G, fractionated from the limulus lysate. The concentration of (1-->3)-beta-D-glucan in culture supernatants of Candida albicans increased to 1,390.0 pg/ml at 24 hours. The concentration of mannan also increased parallel with fungal growth. However, after digestion of supernatants with endo-(1-->3)-beta-D-glucanase, the reactivity to factor G disappeared, although titers of antimannan monoclonal antibody-based latex agglutination were unchanged. Our study demonstrated that cell suspensions of both C. albicans and Cryptoccocus neoformans activated the limulus factor G, and that not only the conidia form but also the filamentous form of Aspergillus fumigatus reacted with factor G. Various Candida spp. (C. paraspilosis, C. glabrata, C. tropicalis, C. krusei), Saccharomyces cerevisiae, Rhodotorula rubra, Trichosporon beigelii, and A. fumigatus released soluble (1-->3)-beta-D-glucan into their culture supernatants, but C. neoformans and Cunninghamella bertholletiae showed only a small reaction to the G test during their culture. Our results indicate that the G test is a good method for serodiagnosis of deep mycosis and also as a screening tool for contamination of medical devices, drugs, and experimental materials with (1 --> 3)-beta-D-glucan.

Changes in lens organophosphate metabolites in response to endotoxin-induced uveitis

Uveitis was induced in rats by endotoxin administration. The temporal correlation between ocular inflammatory reaction and lens metabolic change was examined. The levels of lens phosphate compounds, adenosine triphosphate (ATP), choline phosphate (CP), and inorganic phosphate (Pi), were measured using 31P-nuclear magnetic resonance (NMR) spectroscopy. Anterior chamber inflammation reaction appeared 12 h after administration, peaked at 24 h, and disappeared by 72 h. Concurrent with the active inflammation, lens Pi increased significantly 22 +/- 17% (p < 0.05) and 23 +/- 15% (p < 0.05), 12 and 24 h after administration, respectively, and returned to normal while the inflammation abated. No significant changes were observed in CP and ATP levels in the lens during the course of inflammation. The time course of the inflammation appeared closely related to the change in Pi level, which may be part of the protective mechanism of the lens against inflammation.

Localization of the gene (SLC1A3) encoding human glutamate transporter (GluT-1) to 5p13 by fluorescence in situ hybridization

The glutamate transporter takes up glutamate to terminate neurotransmission and to prevent neuronal cell death. Chromosomal location of the human glutamate transporter, hGluT-1, gene (SLC1A3) was determined by fluorescence in situ hybridization. SLC1A3 was mapped to chromosome 5p13.

Potentiation of cholecystokinin-induced amylase release by peptide VIP in guinea pig pancreatic acini

The mechanism of the potentiating effect of vasoactive intestinal peptide (VIP) on cholecystokinin (CCK-8)-induced amylase release was studied in isolated and perifused pancreatic acini of the guinea pig. VIP (30 pM-10 nM) potentiated CCK-8 (100 pM)-induced amylase release. Unexpectedly, VIP inhibited CCK-8-induced intracellular Ca2+ oscillations. Forskolin (10 microM), an activator of adenylate cyclase, potentiated CCK-8 (100 pM)-induced amylase release with a time course similar to that observed with VIP. Caffeine (20 mM) inhibited both amylase release and Ca2+ oscillations in response to CCK-8, suggesting that inhibition of Ca2+ oscillations does not necessarily lead to a potentiation of amylase release. When intracellular Ca2+ concentration ([Ca2+]c) was raised by thapsigargin (10 microM), a selective inhibitor of Ca(2+)-ATPase in the endoplasmic reticulum (ER), VIP (10 nM) induced significantly greater amylase release than that induced by VIP alone. When [Ca2+]c was lowered by preincubation with BAPTA-AM (25 microM), a cell-permeant Ca2+ chelator, VIP-induced amylase release was completely abolished. These results suggest that VIP, in spite of its inhibitory action on Ca2+ oscillations, facilitates a Ca(2+)-dependent process distal to the increase in [Ca2+]c to potentiate CCK-8-induced amylase release.