Design and its application of the f(n)-zeta chart capable of direct readout of the highest frequency indicating the limit of obtaining distortion-free waveforms

We have already reported that the highest frequency (f(h)) could serve as an index for evaluating the fidelity of pressure waveform derived via a catheter manometer system and be read off by the f(n)-zeta chart. Fh is determined by the natural frequency (f(n)) and damping coefficient ( zeta ) in the frequency characteristics of the system. Inversely, f(h) determines two pairs of f(n) and zeta in the f(n)-zeta chart, one in the case of zeta < 0.7 and the another zeta > 0.7. Then, each pair of f(n) and zeta determines respectively the resonant frequency (f(r)) and its amplitude (Ar) ( zeta < 0.7), or the corner frequency (f(c)) and its amplitude (Ac) ( zeta > 0.7) in the frequency characteristics. Thus, the point (f(r), Ar) or (f(c), Ac) represents the position of f(h) projected in the frequency characteristics. Repeating the same operation for other f(n) and zeta corresponding to the same f(h), yields the curve of f(h) in the frequency characteristics. Calculations for other f(h)'s provide a group of curves. Frequency characteristics of pulmonary artery catheters were measured and overwritten thereupon, resulting in f(h)'s to be from 1.2 to 3.2 Hz. These results were in agreement with that calculated by the conventional method.     

De novo germinoma in the brain in association with Klinefelter's syndrome: case report and review of the literature

BACKGROUND: There are no previous reports about de novo germ cell tumors without any past history of germ cell tumor. We describe a case of de novo cerebral germinoma in association with Klinefelter's syndrome. CASE DESCRIPTION: A boy had undergone growth hormone therapy for dwarfism because of hypopituitarism from 10 to 17 years old. The result of karyotyping at the age of 13 was 47,XXY. Magnetic resonance images (MRI) of the brain at the age of 17 years showed no lesions. Two years later, at the age of 19, the patient noticed onset of mild right hemiparesis. MR imaging revealed the existence of a brain tumor in the left temporal lobe and hypothalamus. The patient underwent an operation and the histologic diagnosis of the lesion was germinoma. After postoperative chemotherapy and radiation therapy, the lesion disappeared and the patient was discharged uneventfully. CONCLUSIONS: To the best of the authors' knowledge, this is the first reported case of a germ cell tumor to be de novo without any past history of other germ cell tumor and the seventh case in which it occurred in association with Klinefelter's syndrome.     

Relationship between aortic-to-radial arterial pressure gradient after cardiopulmonary bypass and changes in arterial elasticity

BACKGROUND: An aortic-to-radial arterial pressure gradient may develop during and after cardiopulmonary bypass (CPB). The mechanisms of this pressure gradient remain controversial. To clarify the cause of the pressure gradient after CPB, the authors investigated the relationship between the pressure gradient and changes in the pulse wave velocity (PWV) before and after CPB. METHODS: The pressure gradient from the aorta to the radial artery and a change in PWV were measured with a wire (0.37 mm in diameter) tipped with a miniature pressure transducer in 12 patients undergoing cardiac surgery. The pressure distributions and waveforms were measured and recorded with electrocardiograph. The PWV was calculated by measuring the propagation time between the R wave of the electrocardiograph and the rising point of the arterial pressure waveform at 10-cm intervals. RESULTS: After CPB, 7 of 12 patients demonstrated a marked pressure gradient. In these patients, the pressure distribution showed a gradual decrease toward the periphery without a precipitous step-down in pressure at any one specific anatomic location. The PWV decreased as the intraarterial pressure decreased from the aorta to the radial artery, and the relative arterial elasticity decreased linearly toward the periphery. CONCLUSIONS: The results showed that the decrease in PWV implies a decrease in arterial elasticity, and the decrease in the arterial elasticity correlated with the decrease in intraarterial pressure. These findings demonstrated that a radial artery pressure lower than the aortic pressure after CPB may be due to the decrease in arterial elasticity.     

The number of CD10-positive glomerular epithelial cells reflects renal prognosis in IgA nephropathy patients

BACKGROUND: The glomerular epithelial cells play an important role in glomerular filtration of the kidney. The disruption of these cells contributes to the development of glomerulosclerosis. The present study was performed to elucidate whether loss of the glomerular epithelial cells is associated with renal injury in patients with IgA nephropathy. PATIENTS AND METHODS: Thirty renal biopsy specimens from IgA nephropathy, 12 from minor glomerular abnormalities and 5 from normal controls were observed. The specimens from IgA nephropathy were divided into 2 groups: Group IgA-1, including 11 patients who had received a follow-up renal biopsy because of deterioration of renal function, and Group IgA-2, consisting of the remaining 19 patients without follow-up biopsy. Immunohistochemistry was performed using a monoclonal antibody against CD10 antigen that appears on mature epithelial cells of glomeruli. RESULTS: The average number of CD10-positive glomerular epithelial cells (GECs) was significantly lower in IgA nephropathy than in either minor glomerular abnormalities or the normal controls. In IgA nephropathy, there were significant correlations of the GECs with renal functions. The GECs were reduced along with the progression of histopathological damage. In group IgA-1, the GECs were significantly reduced at the second biopsy compared with the first biopsy, and significantly fewer in group IgA-1 than in group IgA-2 at the first biopsy. The GECs showed a significant correlation with renal prognosis during the follow-up period. CONCLUSIONS: The reduction of GECs was associated with renal dysfunction, histopathological damage and renal prognosis. The GECs may be a useful predictor of renal prognosis in IgA nephropathy.     

Simultaneous determination of carisoprodol and acetaminophen in an attempted suicide by liquid chromatography-mass spectrometry with positive electrospray ionization

An adult female ingested a considerable quantity of carisoprodol/acetaminophen tablets, which are not commercially available in Japan, in an attempt to commit suicide. Generally, because of lack of the appreciable ultraviolet absorbance or fluorescence, carisoprodol and its major metabolite meprobamate are determined by gas chromatography or gas chromatography-mass spectrometry. Complicated derivatization is, however, necessary to that methodology. Thus, we investigated the derivatization-free, highly sensitive, and simultaneous determination of carisoprodol, meprobamate, and acetaminophen by means of liquid chromatography-mass spectrometry (LC-MS) with positive electrospray ionization. A semi-micro ODS column was used. Ammonium acetate solution (10mM) and acetonitrile were used as mobile phase at a flow rate of 150 microL/min using gradient elution. MS parameters were as follows: capillary voltage, 3.5 kV; cone voltage, +30 V; extractor voltage, 5 kV; and ion source temperature, 100 degrees C. Urine samples pretreated by Oasis HLB cartridge, or plasma samples deproteinized by adding ice-cold acetonitrile were analyzed by LC-MS. The limits of quantitation for each compound were as follows: 0.50 ng/mL for carisoprodol; 10 ng/mL for acetaminophen; and 1.0 ng/mL for meprobamate. In the present case, carisoprodol and acetaminophen were the only drugs detected. Meprobamate was also found as the metabolite of carisoprodol in both urine and plasma. The plasma levels of carisoprodol, acetaminophen, and meprobamate on arrival were 29.5, 245, and 46.7 microg/mL, respectively. These levels were extremely high compared with therapeutic plasma concentrations. Despite the high plasma concentrations of these drugs, which correspond to fatal levels, the patient survived.     

Blind endobronchial insertion of a movable bronchial blocker attached to an endotracheal tube, Univent tube

The endotracheal tube with a movable bronchial blocker, Univent tube, used to effect one-lung ventilation is easy to use in endotracheal intubation. However, problems are often encountered when inserting the blocker into the bronchus. We herein describe a method which enables the easy blind insertion of the blocker into the left or right bronchus. The techniques of inserting the blocker into the left main stem bronchus will be described. With the patient in a supine position, the head of the patient is moved to the left. The operator then places his right hand fingers near the cricoid and presses to displace the larynx of the patient toward the right. While performing this procedure, the operator advances the blocker using the left hand. Finally, using a bronchoscope, the placing of the blocker is to be ascertained in an appropriate position inside the left bronchus. When strong resistance is left, the blocker should be retracted, the force of laryngeal displacement is altered and, then, the blocker is inserted again in a resistance-free manner. We have so far experienced no complications such as severe tracheobronchial hemorrhage, tracheobronchial perforation of laryngeal dislocation. We herein describe a useful and simple method for inserting the bronchial blocker of the Univent tube into the bronchus.     

Regulation of the Fanconi anemia pathway by monoubiquitination

Fanconi anemia (FA) is an autosomal recessive cancer susceptibility syndrome characterized by multiple congenital anomalies, bone marrow failure, and cellular sensitivity to mitomycin C (MMC). To date, six FA genes have been cloned, and the encoded proteins function in a novel pathway. The FA pathway is required for the normal cellular response to DNA damage. Following DNA damage, the pathway is activated, leading to monoubiquitination of the FA protein, FANCD2, and its targeting to subnuclear foci. Disruption of the FA pathway results in the absence of FANCD2 nuclear foci, leading to the cellular and clinical abnormalities of FA. Here, we review the recent studies describing the regulated monoubiquitination of the FANCD2 protein and discuss the interaction of the FA pathway with other DNA damage response pathways.     

Four cases of spontaneous rupture of the urinary bladder

Between November 1997 and March 2001, 4 female patients from 44 to 65 years of age with a spontaneous rupture of the urinary bladder were analyzed. They complained of abdominal pain and had undergone an intra-pelvic gynecological operation (3 for uterine cancer, 1 for an ovarian cyst) several years before. The three with uterine cancer had also received radiation therapy. For their present condition, spontaneous urinary bladder rupture, their treatment was indwelling a urethral catheter. Two of them have had no recurrence of urinary bladder rupture after one month since having the urethral catheter indwelt. One, however, had to have the catheter re-indwelt due to unsuccessful suturing of the urinary bladder wall. The fourth patient had bilateral nephrostomy tubes due to severe radiation cystitis. Thus, one can infer that intra-pelvic gynecological operations and radiation therapy are major factors causing spontaneous urinary bladder rupture. While indwelling a urethral catheter may be effective for some patients with a spontaneous rupture of the urinary bladder, it may be very difficult to treat more complicated cases.