Processing of high-molecular-weight form adrenocorticotropin in human adrenocorticotropin-secreting tumor cell line (DMS-79) after transfection of prohormone convertase 1/3 gene.

Ectopic ACTH-producing tumors preferentially secrete biologically inactive ACTH precursors and ACTH-related fragments. DMS-79 is known to secrete unprocessed high-molecular-weight (HMW) form ACTH. To determine whether prohormone convertase (PC) 1/3 is involved in the abnormal processing of proopiomelanocortin (POMC), we studied whether PC1/3 and 2 genes are expressed in DMS-79, and whether overexpression of PC1/3 gene affects POMC processing pattern. Steady-state mRNA levels of PC1/3 and 2 were determined by real-time RT-PCR. Molecular weights of ACTH-related peptides were determined by chromatographical analyses coupled with ACTH and beta-endorphin (beta-END) radioimmunoassays. PC1/3 gene was transfected into DMS-79 by retrovirus transduction using pMX-IP vector encoding PC1/3 cDNA. The steady-state mRNA levels of PC1/3 and 2 in DMS-79 were lower than those in ACTH-secreting and nonfunctioning pituitary tumors. DMS-79 predominantly secreted HMW form with both ACTH and beta-END immunoreactivities by size-exclusion chromatography. After purification by immunoaffinity chromatography with anti-ACTH antibody, the apparent molecular weight of HMW form ACTH was estimated to be 16 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with silver staining. After retroviral transfection of PC1/3 cDNA into DMS-79 and puromycin selection, PC1/3 stably-expressing cell line (DMS-79T) secreted two immunoreactive ACTH components, a major one coeluting with ACTH(1-39) and a minor one as a HMW form as well as two beta- END immunoreactive components coeluting with beta-lipotropic hormone and beta-END, respectively. Thus, we have established PC1/3 stably-expressing cell line (DMS-79T) capable of proteolytically processing ACTH precursor molecule(s) into mature ACTH and beta-END.

Quantifying noise-induced stability of a cortical fast-spiking cell model with Kv3-channel-like current.

Population oscillations in neural activity in the gamma (>30 Hz) and higher frequency ranges are found over wide areas of the mammalian cortex. Recently, in the somatosensory cortex, the details of neural connections formed by several types of GABAergic interneurons have become apparent, and they are believed to play a significant role in generating these oscillations through synaptic and gap-junctional interactions. However, little is known about the mechanism of how such oscillations are maintained stably by particular interneurons and by their local networks, in a noisy environment with abundant synaptic inputs. To obtain more insight into this, we studied a fast-spiking (FS)-cell model including Kv3-channel-like current, which is a distinctive feature of these cells, from the viewpoint of nonlinear dynamical systems. To examine the specific role of the Kv3-channel in determining oscillation properties, we analyzed basic properties of the FS-cell model, such as the bifurcation structure and phase resetting curves (PRCs). Furthermore, to quantitatively characterize the oscillation stability under noisy fluctuations mimicking small fast synaptic inputs, we applied a recently developed method from random dynamical system theory to estimate Lyapunov exponents, both for the original four-dimensional dynamics and for a reduced one-dimensional phase-equation on the circle. The results indicated that the presence of the Kv3-channel-like current helps to regulate the stability of noisy neural oscillations and a transient-period length to stochastic attractors.

An analysis of nonlinear dynamics underlying neural activity related to auditory induction in the rat auditory cortex.

A sound interrupted by silence is perceived as discontinuous. However, when high-intensity noise is inserted during the silence, the missing sound may be perceptually restored and be heard as uninterrupted. This illusory phenomenon is called auditory induction. Recent electrophysiological studies have revealed that auditory induction is associated with the primary auditory cortex (A1). Although experimental evidence has been accumulating, the neural mechanisms underlying auditory induction in A1 neurons are poorly understood. To elucidate this, we used both experimental and computational approaches. First, using an optical imaging method, we characterized population responses across auditory cortical fields to sound and identified five subfields in rats. Next, we examined neural population activity related to auditory induction with high temporal and spatial resolution in the rat auditory cortex (AC), including the A1 and several other AC subfields. Our imaging results showed that tone-burst stimuli interrupted by a silent gap elicited early phasic responses to the first tone and similar or smaller responses to the second tone following the gap. In contrast, tone stimuli interrupted by broadband noise (BN), considered to cause auditory induction, considerably suppressed or eliminated responses to the tone following the noise. Additionally, tone-burst stimuli that were interrupted by notched noise centered at the tone frequency, which is considered to decrease the strength of auditory induction, partially restored the second responses from the suppression caused by BN. To phenomenologically mimic the neural population activity in the A1 and thus investigate the mechanisms underlying auditory induction, we constructed a computational model from the periphery through the AC, including a nonlinear dynamical system. The computational model successively reproduced some of the above-mentioned experimental results. Therefore, our results suggest that a nonlinear, self-exciting system is a key element for qualitatively reproducing A1 population activity and to understand the underlying mechanisms.

Successful T-cell Replete Hematopoietic Stem Cell Boost Without Conditioning for Late Graft Failure.

Late graft failure is a rare but significant complication after allogeneic stem cell transplantation, which is often complicated by severe infections. We report a case of late graft failure, which was successfully treated with a T-cell replete hematopoietic stem cell boost without conditioning that induced rapid engraftment and relieved the patient of infection. Discontinuation of immunosuppressants and nilotinib administration suppressed the host cells. Achieving full donor chimerism allowed us to administer a peripheral blood stem cell boost without conditioning.

Spatio-temporal cholinergic modulation in cultured networks of rat cortical neurons: evoked activity.

We studied the effects of carbachol, a cholinergic agonist, on extracellularly evoked firing of networks in mature cultures of rat cortical neurons, using multi-electrode arrays to monitor the activity of large numbers of neurons simultaneously. These cultures show evoked burst firing which propagates through dense synaptic connections. When a brief voltage pulse was applied to one extracellular electrode, spiking electrical responses were evoked in neurons throughout the network. The response had two components: an early phase, terminating within 30-80 ms, and a late phase which could last several hundreds of milliseconds. Action potentials evoked during the early phase were precisely timed, with only small jitter. In contrast, the late phase characteristically showed clusters of electrical activity with significant spatio-temporal fluctuations. The late phase was suppressed by applying a relatively small amount of carbachol (5 microM) in the external solution, even though the spontaneous firing rate was not significantly changed. Carbachol increased both the spike-timing precision and the speed of propagation of population spikes, and selectively increased the firing coincidence in a subset of neuron pairs in the network, while suppressing late variable firing in responses. Hence, the results give quantitative support for the idea that cholinergic activation in the cortex has a general role of focusing or enhancing significant associative firing of neurons.

Spatio-temporal cholinergic modulation in cultured networks of rat cortical neurons: spontaneous activity.

Activation of the cholinergic innervation of the cortex has been implicated in sensory processing, learning, and memory. At the cellular level, acetylcholine both increases excitability and depresses synaptic transmission, and its effects on network firing are hard to predict. We studied the effects of carbachol, a cholinergic agonist, on network firing in cultures of rat cortical neurons, using electrode arrays to monitor the activity of large numbers of neurons simultaneously. These cultures show stable spontaneous synchronized burst firing which propagates through dense synaptic connections. Carbachol (10-50 microM), acting through muscarinic receptors, was found to induce a switch to asynchronous single-spike firing and to result in a loss of regularity and fragmentation of the burst structure. To obtain a quantitative measure of cholinergic actions on cortical networks, we applied a cluster Poisson-process model to sets of paralleled spike-trains in the presence and absence of carbachol. This revealed that the time series can be well-characterized by such a simple model, consistent with the observed 1/f(b)-like spectra (0.04

Expression of plasminogen-related gene B varies among normal tissues and increases in cancer tissues.

We previously found that the promoter activity of plasminogen (PLG)-related gene B (PRGB) was 5-fold that of PLG. We have since examined the transcript levels of PRGB among various normal human tissues, and compared these findings with those of PLG. Reverse transcription-PCR analysis revealed that the PRGB expression varied widely among different tissues, while PLG was expressed only in the liver and kidney. RNA samples obtained from cultured cell lines also demonstrated differing PRGB expression. Furthermore, increased PRGB expression was observed in several fresh samples of cancer tissue obtained from cancer patients when compared with surrounding normal tissues.

Microdeletion of the DAZ (deleted in azoospermia) gene or the YRRM (Y chromosome ribonucleic acid recognition motif) gene does not occur in patients with Klinefelter's syndrome with and without spermatogenesis.

OBJECTIVE: To evaluate the occurrence of microdeletions of the Y chromosome involving the DAZ and YRRM genes in patients with Klinefelter's syndrome with and without spermatogenesis. DESIGN: Controlled clinical study. SETTING: Yamagata University Hospital, Yamagata, Japan. PATIENT(S): Patients with Klinefelter's syndrome with spermatogenesis (n = 1) and without spermatogenesis (n = 20) and a control group of men of proven fertility (n = 10). INTERVENTION(S): Blood and semen sampling and testicular biopsy. MAIN OUTCOME MEASURE(S): Semen analysis, polymerase chain reaction amplification of 32 DNA loci on the long arm of the Y chromosome involving the DAZ (deleted in azoospermia) and YRRM (Y chromosome ribonucleic acid recognition motif) genes, and measurement of plasma FSH, LH, and testosterone levels. RESULT(S): No microdeletions of 32 loci were found in any of the patients with Klinefelter's syndrome, either with or without spermatogenesis. Plasma LH and FSH levels were abnormally high and testosterone levels were reduced in all the patients with Klinefelter's syndrome. American Society for Reproductive Medicine.) CONCLUSION(S): Severe impairment of spermatogenesis in patients with Klinefelter's syndrome is not caused by microdeletions of the Y chromosome involving the DAZ and YRRM genes.

Round spermatids from prepubertal mouse testis can develop into normal offspring.

We investigated fertilization and embryo development after intracytoplasmic injection of round spermatids collected from mice before puberty. The rates of normal fertilization, blastocyst formation, and development into live offspring were examined. The injection of oocytes with round spermatids from mature or prepubertal males resulted in similar rates of normal fertilization and embryo development. The rates of the development to term of two-cell embryos were also similar, regardless of the origin of the round spermatids injected. This finding suggests that round spermatids from the prepubertal testis already have the ability to fertilize normally and to allow normal embryo development.

Posterior retroperitoneoscopic partial adrenalectomy using ultrasonic scalpel for aldosterone-producing adenoma.

BACKGROUND: Posterior retroperitoneoscopic adrenalectomy has become a standard procedure, but removal of the entire gland is not necessary in all cases. PATIENTS AND METHODS: We performed 10 posterior retroperitoneoscopic partial adrenalectomies for aldosterone-producing adenoma (APA) using an ultrasonic scalpel to divide the normal adrenal gland and the adenoma. RESULTS: The mean operation time and blood loss were 154 (110-231) minutes and 11 (5-32) mL, respectively. The mean weight of removed tissue was 5.7 g (2.3-10.2 g). Subcutaneous emphysema occurred in three patients, but there were no serious operative complications. CONCLUSION: Posterior retroperitoneoscopic partial adrenalectomy using the ultrasonic scalpel may be a valuable treatment for typical solitary APA.

Successful embolization of a renal artery aneurysm with preservation of renal blood flow.

A 76-year-old man with renal artery aneurysm was successfully treated by transcatheter embolization with complete preservation of renal blood flow. Embolization was performed with detachable platinum coils. Two months later, follow-up angiography showed completely packed aneurysm and preserved blood flow of the branch. It may be reasonable to consider that embolization of the aneurysm is the primary treatment modality for some of the patients with renal artery aneurysm.

Ultrastructure of Leydig cells in Down's syndrome.

Hormonal and ultrastructural examinations of the testis were performed in a patient with Down's syndrome. Plasma testosterone was abnormally low, and circulating levels of LH and FSH were higher than the normal range. The administration of HCG resulted in a low response of plasma testosterone. Electron microscopy revealed proliferation of smooth endoplasmic reticulum, an increase in paracrystalline inclusions and the absence of Reinke's crystals in Leydig cells.

Serum concentration of iopamidol after retrograde urethrography in male patients with outlet obstructive symptoms.

Serum concentration of iopamidol was measured in 29 male patients with outlet obstructive symptoms after retrograde urethrography. Although no patient showed extravasation, serum iopamidol level was detectable in 4 (14%) patients. Since severe adverse effects are considerably reduced with iopamidol, we prefer to use this contrast medium for retrograde urethrography in male patients with outlet obstructive symptoms.

Pulmonary function after posterior retroperitoneoscopic surgery.

Pulmonary function tests were performed in 12 patients who underwent posterior retroperitoneoscopic surgery, before and on the 3rd and 7th days after operation. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FCV, vital capacity (VC), total lung capacity (TLC), residual volume (RV) and functional residual capacity (FRC) were not significantly different between before and after surgery. It is assumed that posterior retroperitoneoscopic surgery could be performed without impairment of pulmonary function after surgery.

Bilateral cryptorchidism associated with 47,XYY karyotype.

We describe an 11-month-old boy with karyotype of 47,XYY who presented with bilateral cryptorchidism, and discuss the hormonal condition of the patient.

[Tuberculin skin test among medical college students].

The incidence of active tuberculosis in Japan has markedly decreased in the past few decades. It is also reported that the prevalence of tuberculosis infection in young population has been decreasing in accordance with the decline in the overall occurrence of tuberculosis. The above mentioned facts indicate that the younger population has a greater risk of developing tuberculosis once exposed to tuberculosis infection. Actually, the epidemics of tuberculosis among the adolescent population have often been reported in recent years. We performed a tuberculin skin test on our medical college students, who might be exposed to tuberculosis infection during their student clinical internship, in order to obtain the information about their present status of reaction to the tuberculin skin test. The data obtained from students between 18 and 25 years old were analyzed using Student's t test and Kruskal-Wallis's method. The mean size of erythema in the group of 23, 24 and 25 years old were significantly greater than that in the group of 20, 21 and 22 years olds. Similarly the latter was significantly greater than that in the group of 18 and 19 years olds. Furthermore, it was proven by the Kruskal-Wallis's method that the older a group was, the greater the chance of a large erythema. One explanation for this fact might be a decrease in the prevalence of tuberculosis infection in the younger generation as described above. Another explanation seems to be related to the revision of the Tuberculosis Prevention Law in 1974.(ABSTRACT TRUNCATED AT 250 WORDS)

[The efficacy of X-ray signs for differential diagnosis of small lung cancer and tuberculoma. Committee for Lung Cancer Mass Screening, JATA].

In order to evaluate the efficacy of X-ray signs for the differential diagnosis of small lung cancer from tuberculoma, a cooperative study was carried out. X-ray films of 64 cases (lung cancer 35, tuberculoma 29) were read by 11 experienced chest physicians independently. The positivity of various X-ray signs were assessed respectively and obtained data were analysed with ROC analysis method. "Ill defined contour", "unevenness of density", "paleness" were proved to be relatively useful as a diagnostic tool, but "notch", "pleural indentation" were not useful in differentiating lung cancer from tuberculoma. It was also noted that great interindividual variations existed on the judgements of X-ray signs among chest specialists, and the conquest of which may be a crucial key for the universal validity of these signs.

[Early steroid withdrawal after kidney transplantation].

BACKGROUND: The side effects of steroid are serious problems in renal transplant patients. However, withdrawal of steroid has been controversial. We evaluated the benefits and risk of early steroid withdrawal after renal transplantation. PATIENTS AND METHODS: The outcomes of early steroid withdrawal from triple immunosuppressive drug therapy were analyzed in four living related and one cadaveric renal transplant recipients. The dosage of steroid was gradually reduced and the time of steroid withdrawal after transplantation was 5 to 7.5 months. RESULTS: Four Patients have been able to be free from steroid and maintained stable graft functions and normal urinary findings for 14 to 33 months after withdrawal. The findings of rejection were not observed in the graft specimens obtained by serial biopsies. One patient who received a living related graft developed an increase in serum creatinine level and proteinuria two weeks after discontinuation of steroid. The serum creatinine level returned to that before withdrawal and proteinuria disappeared by steroid readministration. Long term side effects of steroid were not observed in 4 patients with successful steroid withdrawal. CONCLUSION: These results suggest that steroid withdrawal about 6 months after transplantation can be accomplished without jeopardizing graft function in selected renal transplant recipient and the withdrawal in the early stage is preferred for reducing the side effects. Careful and long-term follow up are required to assess the further risk and benefit of steroid withdrawal on immunosuppressive morbidity.