Enhancement of nitroxide-reducing activity in rats after chronic administration of vitamin E, vitamin C, and idebenone examined by an in vivo electron spin resonance technique

Rats were given vitamin E (Vit-E), idebenone (ID), or vitamin C (Vit-C) in their food for 2 or 4 weeks. After feeding, the ability of rats to reduce 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) in terms of the half-life of Tempol was examined as a specific marker. Tempol was repeatedly injected intravenously, and its half-life was serially evaluated by an in vivo electron spin resonance (ESR) technique. The radical-reducing ability in rats was enhanced differently by Vit-E, ID, and Vit-C, i.e., slow onset of the ability after Vit-E and ID (lipid-soluble antioxidants) and fast onset after Vit-C (a water-soluble antioxidant).

A pilot study of dehydroepiandrosterone sulfate in myotonic dystrophy

We studied the effect of i.v. administration of a dehydroepiandrosterone sulfate (DHEAS) preparation (200 mg/day for 8 weeks) in 11 patients with myotonic dystrophy (MyD). After DHEAS, activities of daily living improved, muscle strength increased, and myotonia decreased. Conduction block and premature beats also improved in the four patients with cardiac involvement. This pilot study may provide a rationale for a controlled study of DHEAS in MyD.

Isolation and characterization of a cytokinin up-regulated gene from tobacco mesophyll protoplasts

We have isolated a cytokinin up-regulated cDNA clone, H13, from an early stage of cultured tobacco mesophyll protoplasts by a differential display method. The expression of this gene was specifically induced by natural and synthetic cytokinins including N-(2-chloro-4-pyridyl)-N'-phenylurea (4PU30), a diphenylurea-type cytokinin, although the simultaneous presence of auxin was also required. It seems that the preceding treatment of the tobacco mesophyll protoplasts by auxin is necessary for the gene to respond to cytokinin. The addition of a cytokinin antagonist, compound 182, which suppressed the induction of cell division in tobacco mesophyll protoplasts, completely abolished the expression of this gene. Though the predicted gene product of H13 did not suggest us any sequences of defined functions, two domains of the predicted sequence had significant homology to several reported sequences in the data base. The gene product of H13 is proposed to have a role in regenerating cell wall in cultured protoplasts, since a cDNA clone E6, from cotton fiber cells, which has the most closely related structure to H13, has been isolated from cells which showed active cellulose synthesis. This supposition is supported by the evidence that in the absence of cytokinin, cell wall regeneration was significantly suppressed, resulting in failure of the induction of cell division. Thus, the gene product of H13 is supposed to have a role in regenerating cell walls and facilitating the progression of the cell cycle, resulting in the sustained cell division of tobacco mesophyll protoplasts.

E2F3 activity is regulated during the cell cycle and is required for the induction of S phase

Previous work has demonstrated the important role of E2F transcription activity in the induction of S phase during the transition from quiescence to proliferation. In addition to the E2F-dependent activation of a number of genes encoding DNA replication activities such as DNA Pol alpha, we now show that the majority of genes encoding initiation proteins, including Cdc6 and the Mcm proteins, are activated following the stimulation of cell growth and are regulated by E2F. The transcription of a subset of these genes, which includes Cdc6, cyclin E, and cdk2, is also regulated during the cell cycle. Moreover, whereas overall E2F DNA-binding activity accumulates during the initial G1 following a growth stimulus, only E2F3-binding activity reaccumulates at subsequent G1/S transitions, coincident with the expression of the cell-cycle-regulated subset of E2F-target genes. Finally, we show that immunodepletion of E2F3 activity inhibits the induction of S phase in proliferating cells. We propose that E2F3 activity plays an important role during the cell cycle of proliferating cells, controlling the expression of genes whose products are rate limiting for initiation of DNA replication, thereby imparting a more dramatic control of entry into S phase than would otherwise be achieved by post-transcriptional control alone.

Paradoxically shortened QT interval after a prolonged pause

We analyzed Holter ECG recordings in 15 patients with episodes of prolonged RR intervals > 2.5 seconds. In 13 patients, the QT interval showed a linear prolongation when RR interval was < 1.5 seconds and became relatively flat at longer RR intervals. In the remaining two patients, the QT and RR intervals were correlated within physiological range of RR intervals. However, at longer RR intervals, the QT interval was unexpectedly shortened and constant. The paradoxically shortened QT interval observed in the present 2 cases may indicate an abnormal adaptation of repolarization time to an abrupt increase in the preceding RR intervals.

A case of hemolytic uremic syndrome associated with emphysematous cholecystitis and a liver abscess

Hemolytic uremic syndrome (HUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. Most cases of HUS are characterized by a prodromal phase of diarrhea and melena, and affect mainly children. Here we report a unique case of adult-onset HUS that was associated with emphysematous cholecystitis and a liver abscess. The patient did not suffer from diarrhea or melena on admission, but abdominal CT scans revealed emphysematous cholecystitis and a liver abscess. Cholecystectomy was performed and the liver abscess was drained. Cultures of the bile and liver abscess contents were negative, but the serum samples had antibodies against Escherichia coli (E. coli) O157. The patient was anuric for 14 days, and underwent hemodialysis that was repeated 15 times and plasma exchanges 6 times. She recovered from acute renal failure but with inadequate urinary concentrating ability as a sequela. Histopathological examination of renal biopsy specimens on the 83rd hospital day revealed almost normal glomeruli and patchy atrophy of tubules with an increase of interstitium. This is a very rare case of HUS associated with emphysematous cholecystitis and a liver abscess successfully treated with aggressive supportive care. It is possible that an infection with verotoxin-producing E. coli O157 caused the disease.

Postrest shortening of the action potential duration in rabbits: in vitro and in vivo correlation

Previous evidence has shown that the action potential duration of rabbit ventricular muscle cells shortens after a rest period (postrest shortening). However, there has not been much research on postrest shortening in the intact heart. We recorded transmembrane action potentials (TAPs) of isolated papillary muscle from rabbit ventricle with glass microelectrodes and monophasic action potentials (MAPs) of the rabbit left ventricular endocardium with contact electrodes. In the in vitro experiments, repetitive regular stimuli (S1) at a cycle length of 1 sec were followed by a single extrastimulus (S2) at coupling intervals (S1S2) ranging between 0.5 sec and 8 sec. The increase in the S1S2 interval resulted in a progressive shortening of the duration of TAP elicited by the S2, which was abolished by the simultaneous application of 1 mmol/L 4-aminopyridine and 2 micromol/L ryanodine. In the in vivo experiments, regular right ventricular pacing (S1) at a cycle length of 0.35 sec was followed by a single extrastimulus (S2) with coupling intervals (S1S2) ranging between 0.25 sec and 3 sec. The increase in the S1S2 interval also resulted in a progressive shortening of the duration of MAP elicited by the S2. This is the first report to demonstrate postrest shortening in the intact heart, which probably occurs because of a mechanism analogous to that observed in the isolated ventricular muscle.

Case report: Alanine aminotransferase deficiency detected in a patient with chronic hepatitis C

We report a case of alanine aminotransferase (ALT) deficiency in a 68-year-old Japanese female with chronic hepatitis C. The serum was positive for antibody to hepatitis C virus (HCV) and HCV-RNA. Liver biopsy showed histological evidence of chronic active hepatitis. The level of serum aspartate aminotransferase (sAST) was elevated, but sALT was extremely low. The patient was followed up for her serum aminotransferase levels for 1.5 years under the treatment with ursodeoxycholic acid. The low sALT level persisted during all the follow-up period. The ALT activity in liver tissue was also decreased. Based on these findings, ALT deficiency was suspected. sALT activity was also found to be low in her two sons. This latter finding suggests the hereditary character of this abnormality.

Circadian rhythm of the signal averaged electrocardiogram and its relation to heart rate variability in healthy subjects

OBJECTIVE

To examine the circadian variation in the signal averaged electrocardiogram (saECG) and heart rate variability and investigate their relations in healthy subjects.

METHODS

24 hour ECGs were obtained with a three channel recorder using bipolar X, Y, and Z leads in 20 healthy subjects. The following variables were determined hourly: heart rate, filtered QRS (f-QRS) duration, low and high frequency components of heart rate variability (LF and HF), and the LF/HF ratio.

RESULTS

Heart rate, f-QRS duration, HF, and the LF/HF ratio showed significant circadian rhythms, as determined by the single cosinor method. Heart rate and the LF/HF ratio increased during daytime, and f-QRS duration and HF increased at night. f-QRS duration was negatively correlated with heart rate (r = 0.95, p < 0.001) and the LF/HF ratio (r = 0.94, p < 0.001) and positively with HF (r = 0.93, p < 0.001).

CONCLUSIONS

f-QRS duration has a significant circadian rhythm in healthy subjects and is closely related to the circadian rhythm of autonomic tone.

[Aqueous levels of eosinophil cationic protein and major basic protein in patients with retinal detachment associated with atopic dermatitis]

We measured the aqueous levels of eosinophil cationic protein (ECP) and major basic protein (MBP) to investigate a possible relationship between cytotoxic eosinophil granule proteins and retinal detachment (RD) in patients with atopic dermatitis. While aqueous ECP was detected in only 1 of 15 cases of RD associated with atopic dermatitis, aqueous MBP was detected in 6 of 14 cases (42.9%). 11 cases of RD without atopic dermatitis were also studied, but neither ECP nor MBP was detected. Although the role of aqueous ECP and MBP was not elucidated, the results indicate that cytotoxic eosinophil granule proteins, especially MBP, are present in aqueous humor in certain cases of RD associated with atopic dermatitis.

Signal-averaged electrocardiogram shows a heart rate dependent diurnal variation in healthy subjects

It has not been determined if signal-averaged electrocardiograms (SAECGs) have a diurnal variation. We recorded 3-channel 24-hour ECGs in 30 healthy volunteers and calculated the following parameters for the first 500 sec of every hour over the 24-hour period: the mean heart rate, the filtered QRS duration (f-QRS), the root-mean-square voltage of the signals in the last 40 msec of the QRS (RMS40), and the duration of low-amplitude signals (< 40 microV) in the terminal portion of the QRS (LAS40). Heart rate and RMS40 increased in the daytime compared with the nighttime; f-QRS and LAS40 increased during the nighttime hours. The f-QRS and LAS40 were negatively correlated with heart rate in all and 22 (73%) of 30 subjects, respectively, and RMS40 was positively correlated with heart rate in 21 subjects (70%). In conclusion, SAECGs exhibit a clear diurnal variation in healthy subjects, which is closely related to changes in heart rate.

Dynamics of QT interval in a patient with long QT syndrome and a normal QT interval

A case report of a 15-year-old girl who experienced syncope and torsades de pointes is presented. The girl had a normal QT interval (QTc=0.37 sec) on the resting electrocardiogram (ECG). Infusion of isoproterenol induced QT prolongation (QTc=0.62 sec) and frequent occurrence of multiform ventricular premature beats. Her Holter ECG showed a prolongation of the QTc interval with a shortening of the RR interval. Low-frequency power (LF) and high-frequency power (HF) of heart rate variability were evaluated from the Holter ECG. The patient showed a statistically significant negative QTc/HF and a significant positive QTc/(LF/HF) relationship, whereas none of the age- and sex-matched healthy subjects showed these relationships. The slope of the QT/RR relationship for the patient was below the lower limit of the normal range. This report describes the unusual relationship of QT interval to RR interval and heart rate variability in a long QT syndrome patient with a normal QT interval on resting ECG.

[Acute renal failure in non-fulminant acute hepatitis without hepatitis A, B or C virus infection]

Here, we report a 35-year-old man with non-fulminant acute non A, non B, non C hepatitis which developed into acute renal failure. The patient was admitted to hospital with the chief complaints of general fatigue, nausea and a high-grade fever of 40 degrees C. Laboratory examination revealed severe liver dysfunction and renal insufficiency on admission: his serum glutamic oxaloacetic transaminase was 3.203 IU/ml, serum glutamic pyruvic transaminase was 3.825 IU/ml, lactic dehydrogenase was 2.840 IU/ml, blood urea nitrogen was 65 mg/dl, and creatinine was 7.6 mg/dl. Hemodialysis was conducted during the initial 19-day period after admission because anuria was manifested on admission. On the 36th day after onset, renal functions returned to normal and the patient was negative for IgM-HA antibody. HBs antigen, IgM-HBC antibody, HCV antibody, cytomegalovirus antibody, and Epstein-Barr virus antibody. However, liver biopsy for histological examination on the 44th day after onset revealed no specific findings except the healing stage of acute hepatitis. Renal biopsy on the 49th day showed the healing stage of acute tubular necrosis without any glomerular change. It has been infrequently reported that acute renal failure develops following a non-fulminant acute state without hepatitis A, B or C virus infection. It is necessary to take acute renal failure into account in the clinical course of non-fulminant non A, non B, non C hepatitis.

Circadian variation of QT interval dispersion: correlation with heart rate variability

The circadian variation of QT interval dispersion and its correlation with heart rate variability (HRV) was examined in 17 normal subjects by using 24-hour recordings of three-lead electrocardiograms. Measurements of HRV, R-R intervals, and QT intervals were made for the first 6 minutes of each hour over a 24-hour period. Spectral analysis of HRV yielded low-frequency power (LF) (0.04-0.15 Hz), high-frequency power (HF) (0.15-0.40 Hz), and the ratio of LF to HF (LF/HF). A rate-corrected QT interval (QTc) was calculated by Bazett's formula, and QT and QTc dispersion was defined as the difference between the maximum and minimum values in any two leads. High-frequency power and QT interval were greater at night than during the day: conversely, LF/HF and dispersion of QT and QTc were greater during the day. The QTc interval remained virtually unchanged throughout the 24-hour period. The dispersion of QTc showed a significant negative correlation with HF and a significant positive correlation with LF/HF. The results suggest that an increased sympathetic tone or a decreased vagal tone increases QT dispersion in healthy subjects.

Transcriptional activation of the human c-myc gene by simian virus 40 large T antigen without binding to p53 and RB proteins in the transient expression system

Transcriptional activation of the human c-myc gene by SV40 large T antigen was examined using HepG2 cells by co-transfecting a T antigen expression plasmid with a myc-CAT construct containing the 2.3-kb upstream region from the P1 promoter and the P2 promoter region fused to the CAT gene. T antigen increased the basal activity of the P2 promoter region containing the E2F binding site, but both the P2 promoter region and the upstream region from the P1 promoter were important for overall activation by T antigen. CAT assay using mutated T antigen lacking p53 or the RB binding site indicated that p53 or RB was not mainly involved in transcriptional activation of the c-myc gene. It appears that activation of the c-myc gene by T antigen is probably dependent upon E2F and a cellular factor through a mechanism which is independent of binding of T antigen to p53 and RB.

[4-year clinico-statistical observation of outpatients]

Clinico-statistical observations were made on the outpatients visiting the Department of Initial Diagnosis and Emergency, Faculty of Dentistry Hospital, Tokyo Medical and Dental University in 1986, 1987, 1989 and 1990. The following findings were obtained according to sex, age group, and chief complaints of new outpatients. Approximately 60% of the outpatients were female during the year examined. The number of outpatients tended to increase in March and to decrease during the winter. The largest number of new outpatients visiting the hospital was in the 20-24-year-old group in both males and females. In the female patients, the 50-54-year-old group had a relatively higher peak. The greatest chief complaint was tooth pain. Further, the chief complaint involving oral soft tissues was due to inflammation. The main disease diagnosed due to chief complaints was caries in the 20-29-year-old group, marginal periodontitis in the 50-59, pericoronitis of wisdom tooth in the 20-29, temporomandibular joint problem in the < or = 19 and masticatory disturbance in the 60 < or = -year-old groups.

In vivo electron spin resonance analysis of nitroxide radicals injected into a rat by a flexible surface-coil-type resonator as an endoscope- or a stethoscope-like device

The flexible surface-coil-type resonator (FSCR) operating in a 700 MHz microwave electron spin resonance (ESR) system was applied to measure the nitroxide radicals at a specific area in rats. The FSCR was composed of a single-turn coil with a diameter of 5 mm and two flexible coaxial lines of 450 mm in length. For an endoscope-like application, the FSCR was inserted into the rectum of the rat and sequential changes in the ESR signals of the intravenously injected nitroxide radical (4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl; TEMPOL or 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy; carbamoyl-PROXYL) were measured. The ESR signal intensity of the nitroxide decreased according to first-order kinetics. For a stethoscope-like application, the FSCR was placed at several sites on the abdominal skin of the rats receiving a subcutaneous injection of carbamoyl-PROXYL, and diffusion and/or metabolism of the radical in the skin was observed.

Evaluation of left ventricular wall motion and function in patients with previous myocardial infarction by three-dimensional 99mTc-HSAD multigated cardiac pool imaging

To evaluate left ventricular (LV) wall motion stereoscopically from all directions and to calculate the LV volume by three-dimensional (3D) imaging. 99mTc-DTPA human serum albumin-multigated cardiac pool-single photon emission computed tomography (99mTc-MUGA-SPECT) was performed. A new data processing program was developed with the Application Visualization System-Medical Viewer (AVS-MV) based on images obtained from 99mTc-MUGA-SPECT. In patients with previous myocardial infarction, LV function and LV wall motion were evaluated by 3D-99mTc-MUGA imaging. The LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were obtained from 3D-99mTc-MUGA images by the surface rendering method, and the left ventricular ejection fraction (LVEF) was calculated at thresholds of 35% (T1), 40% (T2), 45% (T3), and 50% (T4). There was a strong correlation between the LV volume calculated by 3D-99mTc-MUGA imaging at a threshold of 40% and that determined by contrast left ventriculography (LVEDV: 194.7 +/- 36.0 ml vs. 198.7 +/- 39.1 ml, r = 0.791, p < 0.001; LVESV: 91.6 +/- 44.5 ml vs. 93.3 +/- 41.3 ml, r = 0.953, p < 0.001), respectively. When compared with the LVEF data obtained by left ventriculography, significant correlations were found for 3D images reconstructed at each threshold (T1: r = 0.966; T2: r = 0.962; T3: r = 0.958; and T4: r = 0.955). In addition, when LV wall motion obtained by 3D-99mTc-MUGA imaging (LAT and LAO views) was compared with the results obtained by left ventriculography (RAO and LAO views), there was good agreement. 3D-99mTc-MUGA imaging was superior in allowing evaluation of LV wall motion in all directions and in assessment of LV function, since data acquisition and image reconstruction could be done within a short time with the three-detector imaging system and AVS-MV. This method appears to be very useful for the observation of both LV wall motion and LV function in patients with ischemic heart disease, because it is a noninvasive examination.