Genealogical relationships among laboratory strains of <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis> as inferred from matrix metalloprotease genes

Almost all research on Chlamydomonas reinhardtii has utilized wild-type strains of three principal stock lines (Sager, Cambridge, Ebersold-Levine), which traditionally has been assumed to be descendants of a single zygote isolated by Smith. We previously noticed that there are several sequence differences in a single-copy gene of gametolysin, mmp1, between the mt+ and mt- strains employed. To further examine the polymorphisms among the three lines, we obtained 18 representative strains of all three descendant lines of Smith's isolate, nine strains recently isolated from the wild and one strain (CC-1373 mt+) of C. smithii, a strain from Smith's collection interfertile with these C. reinhardtii strains; and we compared the mmp1-3'UTR by RFLP and sequencing analyses. Sequence divergences were found between the mt+ and mt- strains of both the Sager and Cambridge lines, but not between the two mating-type strains of the Ebersold-Levine line. We also examined the polymorphisms, using the 3'UTRs of two other mmp genes and the introns of ypt4 and fus1. Based on the results, we conclude that it is genetically impossible for all the current C. reinhardtii lines to be the immediate descendants of a single zygote.     

Sclerosing mucoepidermoid carcinoma with eosinophilia of the salivary glands

We encountered two cases of low malignant mucoepidermoid carcinoma with scanty cellular atypism which originated in the parotid or submandibular gland and was characterized by marked fibrosis and eosinophilic infiltration within tumor tissue despite the predominance of the squamous component. Here we report these two cases and provide a review of the literature. We believe that clinically these two tumors with stromal fibrosis and eosinophilic infiltration have a low malignant potential, although histological examination revealed a scanty mucus-producing epithelial component. Therefore, we consider this type of tumor as a new subtype of mucoepidermoid carcinoma. A low-malignant mucoepidermoid carcinoma with stromal fibrosis and eosinophilic infiltration, as described in these two cases, may be misdiagnosed as a highly malignant mucoepidermoid carcinoma or squamous cell carcinoma because of its histologically scanty mucus-producing epithelial component. The objective of this study was to clarify their differences and to discuss the rendering of an accurate histological diagnosis, the degree of malignancy in relation to prognosis prediction, and the choice of therapy. In addition, we propose regarding this type of tumor as a new subtype of mucoepidermoid carcinoma.     

Ovarian function in three female patients with McCune-Albright syndrome with persistent autonomous ovarian activity

Autonomous ovarian activity persists throughout adolescence in some patients with McCune-Albright syndrome (MAS). There have been few studies of longitudinal assessment of ovarian function in these patients. We investigated the first morning voided urinary gonadotropin and ovarian steroid levels consecutively in three patients aged 3 to 7 years after withdrawal of therapy for precocious puberty. They had the triad of MAS with onset of menses within the first 3 years of life. Excessively elevated urinary estrogen levels with one or two peaks per cycle were found in all patients. In two patients, café-au-lait spots and dysplastic bones were located unilaterally. These two patients showed significantly increased urinary pregnanediol levels, suggesting ovulation, with low levels of gonadotropins in one patient and moderately low levels with an LH surge in the other. Thus, only a unilateral ovary was anticipated to be mutated with persistent autonomous ovarian activity. In the remaining patient with bilateral involvement of tissues, relatively high LH and low FSH levels throughout a cycle were found with no rise in urinary pregnanediol.     

Comparison of viscoelastic characteristics in triceps surae between Black and White athletes

The purpose of the present study was to investigate race differences in viscoelastic characteristics of triceps surae muscle group. Black and white college sprint type athletes (n=44) participated in this study. Viscoelastic properties were assessed using the free vibration technique: subjects sat with their forefeet on the edge of a force-plate (Kistler, Switzerland) and support a frame loaded with weights (0-40 kg) on the knees. Oscillations of the triceps surae and Achilles tendon system were initiated with a hand-held hammer by tapping the weight load. Oscillations occur at frequencies of 3-6 Hz and were slightly damped. The damped oscillations in conjunction with the equation of motion of a damped mass-spring model were used to calculate the viscosity of muscle (b), and the elasticity of muscle fibres (k(d)) and tendon (k(t)) in each subject. There were little significant differences in most of physical characteristic variables between black and white athletes. Black athletes have significantly greater muscle viscosity and elasticity than white athletes while tendon elasticity is equivalent. Thus, muscle stiffness is greater among black athletes. Greater muscle stiffness could contribute to greater sprint/jump performance among black athletes, compared with white athletes, through alteration of foot/ground contact and take-off phases during sprinting/jumping.     

Dissemination of the phage-associated novel superantigen gene speL in recent invasive and noninvasive Streptococcus pyogenes M3/T3 isolates in Japan

In Japan, more than 10% of streptococcal toxic shock-like syndrome (TSLS) cases have been caused by Streptococcus pyogenes M3/T3 isolates since the first reported TSLS case in 1992. Most M3/T3 isolates from TSLS or severe invasive infection cases during 1992 to 2001 and those from noninvasive cases during this period are indistinguishable in pulsed-field gel electropherograms. The longest fragments of these recent isolates were 300 kb in size, whereas those of isolates recovered during or before 1973 were 260 kb in size. These 260- and 300-kb fragments hybridized to each other, suggesting the acquisition of an about 40-kb fragment by the recent isolates. The whole part of the acquired fragment was cloned from the first Japanese TSLS isolate, NIH1, and its nucleotide sequence was determined. The 41,796-bp fragment is temperate phage phiNIH1.1, containing a new superantigen gene speL near its right attachment site. The C-terminal part of the deduced amino acid sequence of speL has 48 and 46% similarity with well-characterized erythrogenic toxin SpeC and the most potent superantigen, SmeZ-2, respectively. None of 10 T3 isolates recovered during or before 1973 has speL, whereas all of 18 M3/T3 isolates recovered during or after 1992 and, surprisingly, Streptococcus equi subsp. equi ATCC 9527 do have this gene. Though plaques could not be obtained from phiNIH1.1, its DNA became detectable from the phage particle fraction upon mitomycin C induction, showing that this phage is not defective. A horizontal transfer of the phage carrying speL may explain the observed change in M3/T3 S. pyogenes isolates in Japan.     

Vitamin E-bonded hemodialyzer improves atherosclerosis associated with a rheological improvement of circulating red blood cells

BACKGROUND: Vitamin E-bonded hemodialyzer is known to improve oxidative stress in patients with hemodialysis. However, there is little information available as to whether or not this membrane clinically improves atherosclerosis. Furthermore, it remains unknown whether there is any effect of the membrane on rheology of circulating red blood cells. METHOD: We conducted a randomized, open-labeled, prospective control study (N = 34) for 1 year to investigate the effect of vitamin E-bonded cellulose membrane dialyzer (EE) (N = 17) on carotid atherosclerotic changes [intima-media thickness (IMT) of carotid arteries] and the viscosity, percentage of dysmorphism (%DMR) of red blood cells (RBCs) and their distribution width-standard deviation (RDW-SD), in comparison with cellulose membrane (SU) (N = 17) identical to EE without vitamin E-bonded membrane. Erythropoietin (EPO) dose used for the treatment of uremic anemia was also calculated. RESULTS: The IMT significantly decreased in the EE group, while in the SU group the IMT significantly increased. The viscosity of RBCs in hemodialysis patients (4.70 +/- 0.45 cP) was greater than that in healthy individuals (3.73 +/- 0.15 cP). EE significantly improved the viscosity (from 4.84 +/- 0.41 cP to 4.51 +/- 0.54 cP, P < 0.01), %DMR (from 2.29 +/- 2.17% to 1.90 +/- 1.49%, P < 0.01), and RDW-SD (from 54.4 +/- 7.6 fL to 49.3 +/- 5.9 fL, P < 0.01). On the contrary, these parameters all worsened in the SU group. EPO dose needed for the treatment of anemia was significantly (P < 0.05) reduced from 5383 +/- 2655 U/week to 4235 +/- 3103 U/week in the EE group. During these period, mean blood pressure, Kt/V urea, and serum beta2-microglobulin were not changed between the two groups. CONCLUSION: These findings suggest that vitamin E-bonded hemodialyzer is very useful for improving atherosclerosis from a clinical point of view. As one of the underlying mechanisms, as well as antioxidant effects, we want to address an important role of the improvement of rheology of circulating RBCs, which may also help to reduce the requirement of EPO dose in the treatment of anemia of ESRD patients.     

Ventricular diverticula in obstructive hydrocephalus secondary to tumor growth

OBJECTIVE: The association of ventricular diverticula with intra- and paraventricular tumors causing obstructive hydrocephalus has rarely been reported. METHODS: Records and imaging findings for 57 patients with obstructive hydrocephalus caused by tumors who were treated at our institution were reviewed for the presence of ventricular diverticula. For the anatomic study of ventricular diverticula, data were collected from five cadaveric heads. RESULTS: Ventricular diverticula were identified on magnetic resonance imaging scans in five cases. Diverticula were similarly located in the quadrigeminal cistern but originated from the medial wall of the atrium of the lateral ventricle in three cases and from the superior portion of the fourth ventricle in two cases. Regression of diverticula occurred in all cases after either insertion of a shunt or removal of the obstructing tumor. The cadaveric study suggested that the choroidal fissure and the rostral portion of the superior medullary velum might be the origins of diverticula from the atrium and from the superior portion of the fourth ventricle, respectively. CONCLUSION: Ventricular diverticula should be distinguished from other cystic lesions in the quadrigeminal region. Detection of an ostium of a diverticulum or communication between the cyst and the ventricular system is important for diagnosis.     

In vivo test of pressure head and flow rate estimation in a continuous-flow artificial heart

To avoid using sensors with low biocompatibility and low durability in implantable total artificial heart (TAH) systems, the authors previously proposed a new method for estimating instantaneous values of flow rate and pressure head on the basis of voltage, current, and rotational speed in a motor driven centrifugal pump. The previous in vitro experiments showed that the proposed estimator could automatically compensate for the effect of the change in blood viscosity on the estimation accuracy by employing two kinds of autoregressive exogenous models. In this study, validity and reliability of this estimation method were ascertained in an acute animal experiment. In the experiment, two centrifugal blood pumps were implanted into an adult goat as a total artificial heart. Results of estimation were compared with true values when blood viscosity was changed by injecting physiological saline. The results indicated that the system could successfully estimate pressure head by compensating the change of viscosity, although the estimation accuracy of the in vivo estimation was not so high as that of the previous in vitro tests.