Metabolic expression of intrinsic developmental programs for dentine and enamel biomineralization in serumless,chemically-defined,organotypic culture

Summary Biomineralization was investigated using embryonic mouse mandibular first molars (M₁) cultured in the presence or absence of fetal calf serum. Metabolic features including cell division and Ca²⁺ and phosphate incorporation into dentine and enamel extracellular matrices were analyzed. The relative timing and magnitude of DNA synthesis for serumless cultures was comparable toin vivo controls. Isotopic calcium and phosphate incorporation into the mineral phase of dentine and enamel matrices, in the absence of serum, fluctuated during development. Molar tooth morphogenesis, cytodifferentiation, and extracellular matrix formation approximated late crown-stage development in serumless cultures. Von Kossa histochemical staining indicated calcium phosphate salt formation in serumless cultures. Analysis of anhydrous fixation-prepared enamel and dentine representing serumless cultured explants indicated that crystal size and orientation were comparable toin vivo enamel and dentine. In contrast, serum-supplemented cultures showed atypical crystal size and orientation. Calcium/phosphorous (Ca/P) ratio values for serumless cultures after 21 days showed Ca/P enamel values of 2.03 (SD±0.04, p<0.025) and dentine values of 1.89 (SD±0.01, p<0.025). Electron diffraction patterns of enamel and dentine formed in serumless cultures were principally those of highly-ordered crystalline hydroxyapatite. Our results suggest that tissue-specific dentine and enamel biomineralization is regulated by endogenous factors intrinsic to the developmental program of embryonic tooth organs during serumless culture.     

Prevention of vasospastic angina by alcohol ingestion: report of 2 cases

The authors report 2 patients with vasospastic angina in whom alcohol ingestion was effective in preventing angina. Coronary angiography revealed no organic coronary stenosis but demonstrated coronary artery spasm during angina attacks. In 1 patient, alcohol ingestion every six hours completely suppressed frequent spontaneous angina. In the other patient, alcohol ingestion markedly prolonged the duration of the exercise on treadmill testing by preventing exercise-induced coronary spasm.     

Clinical and hemodynamic sequelae of mitral prostheses evaluated by Doppler echocardiography]

To determine the relative superiority of a prosthesis in the mitral position, in vivo hemodynamics were examined by Doppler echocardiography, and the results were compared with other types of mechanical mitral valves including 63 Bj?rk-Shiley convexo-concave (BS) values, 30 Duromedics (DM) valves, and 58 Medtronic Hall (MH) valves. For this comparison, the following indices were evaluated: peak velocity of mitral flow (PV), mitral valve orifice area (MVA), mitral valvular regurgitation, New York Heart Association (NYHA) classification, pulmonary capillary wedge pressure (PC), cardiac index (CI) and valve-related complications. On Doppler echocardiograms, PV ranged from 1.2 to 2.0 m/sec with a mean of 1.6 m/sec. There was no evident relationship between the PV and the valve size in each type of prosthesis, and no significant difference in the PVs among the valves. The mean MVA was 2.6 cm2 (25 mm DM, 25 mm MH), which was regarded satisfactory from a clinical standpoint. MVA increased with the increase in the valve size in all types of valves, and of all sizes, MVA was larger in the DM and MH groups than in the BS group. Similarly, the incidence of valvular regurgitation was relatively low in all groups, and the degree of regurgitation proved to be grade II or less in all cases. As for the clinical results, clinical symptoms (NYHA) and hemodynamic states (PC, CI) improved postoperatively, with the differences among the types of prosthetic valves being insignificant. The incidences of thromboembolism, valvular thrombosis, valve failure and prosthetic endocarditis were relatively low in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of circumstances and/or organs on the grade of cancer growth and malignancy

The effect of circumstances and/or organs on the grade of cancer growth and malignancy was studied, using hereditarily identical VX2 cancer. VX2 cancer cells, 10(6) cells/0.1 approximately 0.2 ml, were injected into the liver, portal vein, stomach- and colon-walls of Japanese white rabbits. Each of the experimental groups consisted of 14, 12, 19 and 24 animals, and 3 or 4 animals of each groups were sacrificed 7, 14, 21 and 28 days after the implantation. All the animals of portal vein and liver groups died of cancer within 3 and 4 weeks respectively. However, all the animals of stomach and colon groups survived during 4 weeks. Although cancer volume doubling time was not calculated in portal group because of the multiple and diffuse tumor-formation, the time was 2.6 days in liver, 4.3 days in colon and 5.9 days in stomach groups in which a single tumor developed. Lymphatic and/or hematogenous metastases were found at the same time after the implantation as vascular invasion occurred. Metastases were confirmed in 100% in liver group and 40% in portal group 2 weeks after the implantation, and 80% and 50% in colon and stomach groups respectively 4 weeks after the implantation. The results suggested that hereditarily identical VX2 cancer was variable in the different organs and circumstances, and that the growing circumstances strongly affected the cancer malignancy. It was also suggested that the malignancy was correlated with the growth rate and the time of metastasis of cancer.     

A study of comparison between Technicon THMS H-2 and Hematrak 590]

Using 655 peripheral blood samples from normal individuals and patients, we evaluated the relationship between the measurements of red blood cell (RBC) and white blood cell (WBC) through the Hematrak 590 (Hematrak) and the generated flag systems in the Technicon H-2 (H-2). 1) Among the 12 VAR (Variation) flag positive samples in H-2, 10 samples were obtained from the patients receiving blood transfusions. The samples with high values of HDW (Hemoglobin distribution width) in H-2 seemed to have hypochromatic and polychromatic changes in RBC. 2) Hematrak is likely to be more sensitive than H-2 in discovering atypical lymphocytes (AL). When AL counts in Hematrak were over 5 or 6% of WBC, these results were coincident with ATYP flag positive in H-2. 3) In our examinations, when %Blast in H-2 was over 4%, BLASTS flag always generated positively. We think that H-2 is a tool with high reproducibility for the detection of the blast-like abnormal cells. 4) We evaluated the results of WBC differential count by the three methods of H-2, Hematrak and manual procedures in the peripheral blood samples from normal individuals. We recognized close correlations in neutrophils, lymphocytes and eosinophils (coefficients of correlation = 0.826-0.911), and relatively close ones in monocytes (r = 0.280-0.562), but no correlations in basophils (r = 0.106-0.281). To comprehend the pathophysiological states of the various diseases hematologically, it is necessary to understand the characteristics of the different measurement principles between the two instruments (H-2 and Hematrak).     

Current concepts and diagnostic evaluation of autoimmune disease

This article discusses autoimmune reactions and the numerous mechanisms by which an autoimmune response may be initiated, including genetic factors, T-cell bypass mechanisms, and idiotypes. Human autoimmune diseases are classified into three main groups, ie, organ-specific, non-organ specific, and disorders with non-organ-specific autoantibodies with lesions restricted to one or a few organs, that are examined in detail. General laboratory tests and interpretation of results in relation to state or treatment of the particular disease, age and sex of the patient, and the sensitivity of the test system used are reviewed.     

Dual concentration-dependent effects of phorbol 12, 13-dibutyrate on spontaneous and acetylcholine-induced electrical responses recorded from isolated circular smooth muscle of the guinea-pig stomach antrum.

Intracellular recordings of electrical activity were made from circular smooth muscle cells in small segments of tissue isolated from the guinea-pig stomach antrum. Every cell that was impaled exhibited a rhythmic generation of slow potentials. Experiments were carried out to test the effects of three different concentrations (1, 10 and 100 nM) of phorbol 12, 13-dibutyrate (PDBu) on these slow potentials and on the responses produced by acetylcholine (ACh), in the presence of nifedipine and N(omega)-nitro-L-arginine (nitroarginine), known inhibitors of L-type Ca-channels and nitric oxide synthase, respectively. The resting membrane potential was -62 +/- 7 mV, while the frequency and amplitude of the slow potentials were 1.6 +/- 0.1 cycle per min (cpm) and 33 +/- 1 mV, respectively. Application of 1 nM PDBu increased the frequency of slow potentials, with no significant change in the membrane potential and amplitude of slow potentials. At a concentration of 100 nM, PDBu depolarized the membrane by about 6 mV, and either decreased the amplitude and frequency of the slow potentials or abolished them. The amplitude and frequency of the slow potentials were not significantly changed in the presence of 10 nM PDBu. In the presence of chelerythrine (1-2 microM), a known inhibitor of protein kinase C (PKC), the increase in frequency of slow potentials by 1 nM PDBu and depolarization produced by 100 nM PDBu were not elicited. The increase in frequency of slow potentials by 100 nM ACh was inhibited by PDBu, in a concentration-dependent manner, and ACh-responses were abolished in the presence of 100 nM PDBu. These results indicate that PDBu has dual actions on the spontaneous activity of antral circular muscle, with low concentrations increasing and high concentrations inhibiting the frequency of the slow potentials. The former may be produced by activation of protein kinase C (PKC). As the ACh-induced excitation of slow potentials is inhibited by PDBu, a possible causal relationship between the inhibition and over-activation of PKC is considered.     

Use of laboratory data to identify risk factors of giant coronary aneurysms due to Kawasaki disease

BACKGROUND: Although some laboratory findings are known to be indicators of the risk of giant coronary aneurysm formation among Kawasaki disease patients, an appropriate cut-off point to predict aneurysm formation is not clear. METHODS: One hundred and five patients with giant coronary aneurysms were selected from the 15th and 16th nationwide surveys of Kawasaki disease in Japan. A total of 2936 patients without Kawasaki disease were recruited from a single hospital as a control group. Odds ratios were calculated for six laboratory data with specific values as cut-off points. Receiver operating characteristic (ROC) curves were observed to determine the most appropriate laboratory tests and cut-off points. RESULTS: Hematocrit, leukocyte count, neutrophil proportion, and hemoglobin had one or more peaks of odds ratio for specific cut-off points, but they did not have a clear cut-off point for the predictor according to the receiver operating characteristic curves. Alanine aminotransferase (ALT) increased the risk of giant coronary aneurysms continuously so no clearly appropriate cut-off point was identified. Serum sodium concentration of 135 mEq/L had a peak of odds ratio, and those with <135 mEq/L had the highest odds ratio (4.78). This value seemed appropriate with a sensitivity of 78% and specificity of 57%, although the predictive positive value was as small as 5%. CONCLUSION: The author's propose that a serum sodium concentration of <135 mEq/L at the patient's first visit to hospital may be a predictor of giant coronary aneurysms due to Kawasaki disease.     

Intrapulmonary Schwannoma

A 58-year-old woman was admitted due to an abnormal shadow on chest X-ray, without any symptoms. Chest computed tomography showed a round mass in the anterior segment of the right upper lobe. Segmentectomy was performed and histopathological examination revealed a primary neurogenic tumor of Schwann cell origin. Immunohistochemical staining demonstrated the presence of S-100 protein in the tumor cells. We present a case of intrapulmonary schwannoma and review 62 cases of primary schwannoma of the lung.     

Differential Effects of Etomidate and Midazolam on Vascular Adenosine Triphosphate-sensitive Potassium Channels: Isometric Tension and Patch Clamp Studies

Background: The aim of this study was to investigate the effects of two imidazoline-derived intravenous anesthetics, etomidate and midazolam, on vascular adenosine triphosphate-sensitive potassium (KATP) channel activity.

Methods: In isolated rat aorta, isometric tension was recorded to examine the anesthetic effects on vasodilator response to levcromakalim, a selective KATP channel opener. Using the patch clamp method, the anesthetic effects were also examined on the currents through (1) native vascular KATP channels, (2) recombinant KATP channels with different combinations of various types of inwardly rectifying potassium channel (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor (SUR1, 2A, 2B) subunits, (3) SUR-deficient channels derived from a truncated isoform of Kir6.2 subunit (Kir6.2[DELTA]C36 channels), and (4) mutant Kir6.2[DELTA]C36 channels with reduced sensitivity to adenosine triphosphate (Kir6.2[DELTA]C36-K185Q channels).

Results: Etomidate (>= 10-6 m), but not midazolam (up to 10-6 m), inhibited the levcromakalim-induced vasodilation, which was sensitive to glibenclamide (IC50: 7.21 x 10-8 m; maximum inhibitory concentration: 1.22 x 10-4 m). Etomidate (>= 3 x 10-6 m), but not midazolam (up to 10-4 m), inhibited the native KATP channel activity in both cell-attached and inside-out configurations with IC50 values of 1.68 x 10-5 m and 1.52 x 10-5 m, respectively. Etomidate (10-5 m) also inhibited the activity of various types of recombinant SUR/Kir6.0KATP channels, Kir6.2[DELTA]C36 channels, and Kir6.2[DELTA]C36-K185Q channels with equivalent potency.