Determination of the prognostic significance of cyclin B1 overexpression in patients with esophageal squamous cell carcinoma

 Recent studies have identified a family of proteins referred to as cyclins, which control the cell cycle. Cyclin B1 activates cdc2, which regulates cell progression through the G2 and M phases. The main aim of this study was to examine the relationships between the cyclin B1 expression in human esophageal squamous cell carcinoma (SCC) and clinicopathological factors and prognosis of the patients. Eighty-seven cases of primary human SCC consecutively obtained at esophagectomy were immunohistochemically studied using an anti-human cyclin B1 protein antibody (2H1-H6). The relationship between cyclin B1 expression and clinicopathological factors, including prognosis, were also statistically assessed. Positive immunostaining of cancer cells, mainly in the cytoplasm, was detected in 72.4% (63/87): heterogeneous pattern in 37.9 % (33/87) and homogeneous pattern in 34.5% (30/87). The prevalence of cyclin B1 expression was significantly higher in cases with invasion deeper than the muscularis propria (P<0.005) and with venous invasion (P<0.01) than in other cases. Patients whose SCCs expressed high levels of cyclin B1 protein had a significantly poorer prognosis than did the other patients (P<0.05). Multivariate analysis demonstrated that cyclin B1 status was an important factor affecting survival (P<0.05). These findings demonstrated that overexpression of cyclin B1 protein is associated with tumor behavior and prognosis for patients with human esophageal SCC. Received: 25 June 1998 / Accepted: 21 October 1998     

HISTOMETRICAL and HISTOLOGICAL CHANGES OF THE SKELETAL MUSCLE IN NEUROMUSCULAR DISORDERS – AN AUTOPSY STUDY

Systemic hlstometrical and histological examinations of major skeletal muscles were performed by using autopsy cases with simple atrophy, neurogenic muscular atrophy, Duchenne type progressive muscular dystrophy, myositis of myasthenia gravis, and autopsy control cases. In hlstometrical studies, the shortest diameters of muscle fibers were measured and arranged in histograms. Volume ratio of stroma to muscle was measured by point-counting method.
Histometrical studies revealed the following results: (1) averages of muscle fiber diameters in controls showed the largest value In the muscles of the upper and lower extremities, and the smallest value in the lingual muscle; (2) in simple atrophy, neurogenic muscular atrophy, progressive muscular dystrophy and myositis, a decrease in muscle fiber diameters was more prominent in the muscles of the lower extremities than those of the upper extremities; (3) patterns of histograms of muscle fiber diameters were classified into six types, and in simple atrophy, almost one-half of muscles examined belonged to type 3 histogram, which had the mode situated at a relatively small diameter and a not so high kurtosls; (4) volume ratios of stroma to muscle Increased most in both muscular dystrophy and long-standing neurogenic muscular atrophy, moderately in myositis, and mildly in simple atrophy; and (5) hlstometrical changes In myasthenia gravis were minimal.     

Regulation of mast cell signaling through high-affinity IgE receptor by CD45 protein tyrosine phosphatase

The transmembrane tyrosine phosphatase CD45 regulates the activity of src family protein tyrosine kinases (PTK) and thereby influences the signaling via such receptors as T and B cell antigen receptors associated with these PTK. However, its implication in signaling through the mast cell receptor with high affinity for IgE (FcepsilonRI) is less clear, although Lyn, a member of the src family, plays an important role in FcepsilonRI-mediated signaling. To define a role for CD45 in FcepsilonRI signal transduction, we established CD45 high expressing rat basophilic leukemia cell lines (RBL-CD45H) and cell lines expressing trace amounts of CD45 (RBL-CD45L). We demonstrate that although all RBL-CD45L cell lines degranulate following IgE- and antigen-induced FcepsilonRI aggregation, the response is significantly reduced at a low dose of antigen. The cells show a delayed and slowed Ca(2+) mobilization even though at a higher dose where the cells degranulate to a similar extent as RBL-CD45H. This diminished Ca(2+) response is restored by reconstitution of RBL-CD45L with a chimeric molecule containing the cytoplasmic phosphatase domains of rat CD45. Furthermore, tyrosine phosphorylation of FcepsilonRI, association of FcepsilonRI with Lyn and PTK activity associated with FcepsilonRI, all of which are enhanced upon FcepsilonRI aggregation in RBL-CD45H, are impaired in RBL-CD45L. Finally, we show that FcepsilonRI is physically associated with CD45 in RBL-CD45H prior to receptor aggregation. Thus, we propose that, although not indispensable in mast cell degranulation, CD45 positively regulates the signaling through FcepsilonRI by promoting the activation of FcepsilonRI-associated Lyn.     

Effects of growth hormone treatment on thyroid function in pediatric patients with Prader–Willi syndrome

It is unclear whether hypothyroidism is present in patients with Prader–Willi syndrome (PWS). This study aimed to clarify the state of the hypothalamic–pituitary–thyroid axis and the effects of growth hormone (GH) treatment on thyroid function in pediatric patients with PWS. We retrospectively evaluated thyroid function in 51 patients with PWS before GH treatment using a thyroid‐releasing hormone (TRH) stimulation test (29 males and 22 females; median age, 22 months). We also evaluated the effect of GH therapy on thyroid function by comparing serum free triiodothyronine (fT3), free thyroxine (fT4), and thyroid stimulating hormone (TSH) levels at baseline, 1 year, and 2 years after GH therapy. TSH, fT4, and fT3 levels were 2.28 μU/ml (interquartile range [IQR]; 1.19–3.61), 1.18 ng/dl (IQR; 1.02–1.24), and 4.02 pg/dl (IQR; 3.54–4.40) at baseline, respectively. In 49 of 51 patients, the TSH response to TRH administration showed a physiologically normal pattern; in two patients (4.0%), the pattern suggested hypothalamic hypothyroidism (delayed and prolonged TSH peak after TRH administration). TSH, fT4, and fT3 levels did not change significantly during 1 or 2 years after GH treatment. The TSH response to TRH showed a normal pattern in most patients, and thyroid function did not change significantly during the 2 years after initiating GH treatment.     

GABAB receptor transduction mechanisms, and cross-talk between protein kinases A and C, in GABAergic terminals synapsing onto neurons of the rat nucleus basalis of Meynert

The transduction mechanisms underlying presynaptic GABA_B receptor-mediated inhibition of transmitter release have been characterized for a variety of synapses in the central nervous system (CNS). These studies have suggested a range of transduction mechanisms, including a role for second messengers such as protein kinases A (PKA) and C (PKC). In the present study, we have examined the intracellular signalling pathways underlying baclofen-induced inhibition of GABA release from terminals synapsing onto rat basalis of Meynert neurons using patch-clamp recordings. Baclofen, a selective GABA_B receptor agonist, reversibly decreased both evoked and spontaneous, miniature, GABAergic inhibitory postsynaptic currents (eIPSCs and mIPSCs, respectively). Such baclofen actions were completely abolished by CGP55845A, a selective GABA_B receptor antagonist, and by staurosporine, a non-selective PKA and PKC inhibitor. The mIPSC frequency was still decreased by baclofen even in the presence of 4 AP, a K⁺ channel blocker, and Cd²⁺, a voltage-dependent calcium channel blocker. Pharmacological activation or inhibition of PKC activity affected basal GABA release and mildly affected the response to baclofen. Inhibition of the cAMP/PKA cascade also affected basal GABA release and, in a subset of neurons, occluded the effects of baclofen, suggesting that the GABA_B receptor-mediated inhibitory action on GABA release was mediated via decreases in PKA activity. In addition, PKA inhibition occluded the effects of PKC modulation on both basal GABA release and on the response to baclofen. Our results characterize the transduction pathway of baclofen at these nucleus basalis of Maynert (nBM) synapses and show, for the first time, some cross-talk between the cAMP/PKA and PKC pathways in mammalian presynaptic nerve terminals.     

Typology of the arteries in the human scalenus region, with special reference to the accessory ascending cervical artery

The accessory ascending cervical artery (Murakami et al., 1996), which arises from the subclavian artery and ascends between the scalenus anterior and medius muscles, was studied in 87 Japanese adult cadavers (174 sides), with special attention being given to its origin, distribution, and relationship to other arteries at the cervical or scalenus region. In 154 sides (88.5%), the accessory ascending cervical artery was found to originate from the subclavian artery behind the scalenus anterior muscle, and to branch out to the scalenus anterior and medius muscles as well as those entering the 5th and 6th intervertebral foramens along the 6th and 7th cervical nerves. This artery arose independently in 105 sides. The accessory ascending cervical artery issued off or formed a common trunk with the transverse cervical artery and/or costocervical trunk in 49 sides. In cases lacking the accessory ascending cervical artery, it was usually compensated for by the costocervial trunk and/or transverse cervical artery (18 sides). Common trunk formation with the vertebral, internal thoracic, or suprascapular arteries was not observed. The authors suggest that the accessory ascending cervical artery, the transverse cervical artery, and the costocervical trunk should be grouped into one arterial system, a system that may be a remnant of the precostal longitudinal anastomoses of intersegmental arteries of the dorsal aorta behind the scalenus anterior muscle.     

Selective decline in protein F1 phosphorylation in hippocampus of senescent rats

Certain forms of neuronal plasticity have been found to be expressed through alterations in brain protein phosphorylation, and its regulation by protein kinase activity. Of interest in this regard is the possibility that the decline in neuronal plasticity and cognitive function that occurs in advanced age may result in part from altered phosphorylation of specific proteins. As a first attempt to identify age-related changes in phosphoproteins, we assayed in vitro phosphorylation of proteins in hippocampus, cerebellum, entorhinal cortex, and frontal cortex from Fischer-344 rats of 5 months, 11 months, and 25 months of age. Compared to the middle-aged animals, the aged rats showed a selective 46% decline in phosphorylation of the 47 kDa protein (F1) in hippocampus, with no change in the phosphorylation of other proteins measured in this structure. Aged animals also showed decreased phosphorylation relative to young animals. No age-related change was observed in any protein band for the other brain areas examined. Since protein F1 is phosphorylated by protein kinase C (PKC), the cytosolic and membrane distribution of this enzyme was compared across age groups. The activity of PKC in hippocampus did not change across age. The explanation of this age-related decline in protein F1 phosphorylation is likely to be a decline in the substrate protein itself. The results are discussed in terms of protein F1's possible role in age-related decline of hippocampal synaptic plasticity.     

Exponential hyperbolic sine function fitting of heart rate response to constant load exercise

We attempted to fit heart rate (HR) changes induced by constant exercise loads of different intensities to an exponential hyperbolic sine curve by the least-squares method, and we compared the results with the fitting of the changes to exponential curves. Seven healthy male volunteers performed three different intensities of constant-load exercise on a bicycle ergometer. The exponential hyperbolic sine function adequately fitted the HR responses induced by all three different intensities of loads: low (30 W: correlation coefficient, r = 0.68 +/- 0.13, mean +/- SD), moderate (75 W: r = 0.93 +/- 0.07) and high (125 W: r = 0.97 +/- 0.02). The first-order exponential curve fitted only the moderate load response. Although the second-order exponential equation fitted the HR response for both the moderate and high loads, the equation did not fit the low-load response (r = 0.43 +/- 0.26). In low-load exercise, the sum of the power of the residuals for the exponential hyperbolic sine curve fitting was significantly smaller than that for the first- or second-order exponential curve fitting. In conclusion, the exponential hyperbolic sine function is useful for quantitative analyses of the HR response to exercise loads of various intensities.     

An enzyme immunoassay for K-76 monocarboxylic acid, a novel anticomplementary compound

A competitive enzyme immunoassay for K-76 monocarboxylic acid (K-76COOH), a novel anticomplementary compound, was developed. K-76COOH was directly coupled with bovine serum albumin through a formation of Schiff base and successive reduction. The spectral data of the conjugate showed no evidence of a Schiff base form. Using the specific antiserum, the proposed homologous assay made it possible to detect K-76COOH at the lowest value of 1 ng/ml of plasma. The immunoassay was validated by the correlation with HPLC analyses. The time courses of plasma levels of K-76COOH after a single oral administration to beagle dogs were precisely determined with a very low absorption efficiency. From these results, it is suggested that the plasma values obtained are insufficient for K-76COOH to exert its anticomplementary action in vivo; thus K-76COOH may have another immunopharmacological function.     

A compact and inexpensive device using an electronic calculator for measuring ambulatory activity in mice

A device for measuring ambulatory activity in mice was developed. The device consisted of a plastic case, a bed plate, a step board (as a detector) and a calculator (as a recorder). A 2.2 cm width section was cut out from the middle of the case bottom in the direction of the minor axis and a step board, a width of 2 cm, was placed in the opening. A short bolt was screwed into one end of the step board and the head of the bolt was placed on the equal key of the calculator. The calculator counted the number of times the mouse stood on the step board. The validity of the device was demonstrated by measuring the effect of methamphetamine (1-4 mg/kg) on the ambulatory activity in mice.