Differential T4 degradation pathways in young patients with preterminal and terminal renal failure.

INTRODUCTION: The aim of this study is to analyze thyroid hormone parameters in large homogenous patient cohorts with preterminal (stage 4) and terminal (stage 5) renal failure in an area of low iodine intake. PATIENTS AND METHODS: Thyroid parameters were measured in healthy controls (n=48), patients with preterminal renal failure (n=48) and patients with terminal renal failure undergoing hemodialysis (n=288). All patients were assessed by measurement of TSH, T4, T3, fT4, rT3, Tg and TPO-antibodies. RESULTS: There was a significant decrease of T4 and fT4 from healthy controls to patients with preterminal renal failure and to patients with terminal renal failure. T3 showed a decrease from healthy controls to patients with preterminal renal failure and to patients with terminal renal failure (1.54+/-0.06 microg/l VS. 1.05+/-0.05 microg/l VS. 1.09+/-0.23 microg/l, p<0.001 VS. controls). rT3 was significantly decreased in patients with terminal renal failure (0.24+/-0.01 microg/l VS. 0.25+/-0.02 microg/l VS. 0.16+/-0.01 microg/l, p<0.001). The rT3/T3 ratio was significantly elevated in patients with preterminal renal failure (p<0.01). TSH concentrations were in the normal range in all groups. CONCLUSION: Our data suggest different T4 degradation pathways in patients with preterminal and terminal renal failure.

[Familial Mediterranean fever]. / Familiäres Mittelmeerfieber.

BACKGROUND: Familial Mediterranean fever (FMF) is characterized by febrile attacks, acute abdominal pain, pleuritis or arthritis and predominantly observed in ethnic groups of the Mediterranean area (Sephardic Jews, Turks, Armenians). Its most ominous manifestation is amyloidosis potentially leading to chronic renal failure. FMF is an inherited disorder caused by mutations of the FMF-gene, which first was described in 1997. CASE REPORT: We report a 10-year old turkish boy and his family presenting with an increased blood sedimentation rate (WBC) and recurrent attacks of acute abdominal pain. A molecular analysis was carried out, confirming a typical mutation of the FMF-gene. The patient remained free of symptoms after starting therapy with colchicine. CONCLUSION: Investigation of the FMF gene enables an early diagnosis in case of clinical suspect findings, subsequent colchicine administration may prevent amyloidosis.

[Hereditary fructose intolerance (HFI) as cause of isolated gamma GT rise in a 5-year old boy with hepatomegaly]. / Hereditäre Fruktoseintoleranz (HFI) als Ursache einer isolierten gamma GT-Erhöhung bei einem 5-jährigen Jungen mit Hepatomegalie.

The diagnosis of HFI is easily missed during childhood. It should be suspected in children presenting with hepatomegaly and an isolated increase in GGT. A carefully taken nutritional history forms the basis of the diagnosis of HFI which can be confirmed by molecular analysis with a sensitivity of > 95%. I.v. fructose tolerance tests and liver biopsies often can be omitted.

[Value of transtracheal oxygen insufflation in the weaning period after long-term ventilation]. / Stellenwert der transtrachealen Sauerstoffinsufflation in der Weaningphase nach Langzeitbeatmung.

BACKGROUND: In many cases, respiratory muscle failure is the reason for unsuccessful weaning attempts after long-term ventilation. Therapeutic measures must therefore be aimed at unloading the respiratory pump. In this present study we examined whether, in particular, the transtracheal O2-insufflation (TTO2) results in a change of breathing patterns and unloads the respiratory muscles. PATIENTS AND METHODS: We examined 6 patients (5 males, age 65.6 +/- 3.9 years, diagnosis: chronic obstructive lung disease), who received long-term mechanical ventilation in outward intensive care units. Baseline resting data (arterial blood gas analysis, the breathing frequency and the minute volume) were obtained with the patients breathing room air for 1 hour. After receiving TTO2 with a flow of 21/min for another 1-hour-period the measurements were repeated. RESULTS AND CONCLUSION: In our study we could show that the TTO2 leads to an impressive decrease in inspiratory work of breathing-relative to the minute ventilation by about 28%. Therefore TTO2 is of great importance in the weaning phase subsequent to prolonged mechanical ventilation due to the respiratory muscle failure.

[Sleep disorders in patients with dialysis-dependent renal failure]. / Schlafstörungen bei Patienten mit dialysepflichtiger Niereninsuffizienz.

A questionnaire was performed in order to classify the prevalence of sleep disorders in patients with end-stage renal disease treated with hemodialysis. 69 patients (41 male, 28 female) with a median age of 57 years completed the questionnaire. 67% of these patients complained of sleep disorders. 31 patients (45%) had evidence of periodic leg movement syndrome, 22 patients (32%) of restless legs syndrome. 29 patients (42%) had difficulties in falling asleep, 27 patients (39%) in maintaining sleep and 17 (25%) experienced both. Snoring was found in 25 patients (36%), 13 patients (19%) seemed to have sleep apnea. These data show an increased prevalence of sleep disorders in patients with end-stage renal disease on hemodialysis treatment. We conclude that these patients should consequently be asked for sleep disorders, as a specific diagnostic and therapeutic regime could improve quality of life and life expectancy. Especially sleep apnea is a disease that has a high prevalence in this patient group and which can be treated successfully.

[Treatment of acute low cardiac output syndrome after surgery of congenital heart defects: value of enoximone]. / Behandlung des akuten Low-cardiac-output-Syndroms nach Operationen angeborener Herzfehler: Stellenwert von Enoximon.

Children undergoing cardiac surgery are at additional risk for postoperative low cardiac output syndrome (LCOS). Anticipation of the syndrome from preoperative hemodynamic condition, surgical procedure, and adverse intraoperative events is a key to successful postoperative management. Inotropic support is primarily based on catecholamines. However, uncoupling of human cardiac beta-adrenoceptors during cardiopulmonary bypass with cardioplegic cardiac arrest may be the reason why many patients respond only weakly to beta-adrenoceptor agonists. Phosphodiesterase (PDE) inhibitors act by reducing intracellular breakdown of cAMP, which is elevated independently from beta-receptors. The use of PDE-inhibitors might be advantageous in patients with uncoupled beta-adrenoceptors, as occurs after cardiopulmonary bypass. In addition, PDE-inhibitors can prevent further downregulation of the adrenoceptors due to avoiding prolonged therapy by beta-agonists. In this context, the addition of enoximone, a PDE-inhibitor, to adrenergic agents has been found useful in increasing cardiac output in children with catecholamine-resistant LCO, as well as in children with compensated hemodynamics during catecholamine therapy.

Short-term starvation decreases POMC mRNA but does not alter GnRH mRNA in the brain of adult male rats.

Dietary restriction reduces circulating gonadotropin and testosterone levels in male rats, an effect thought to be mediated through reduced gonadotropin-releasing hormone (GnRH) secretion; however, the cellular mechanisms subserving this response are still unknown. We reasoned that if dietary restriction reduces GnRH secretion, this would be reflected by a decrease in GnRH synthesis and likewise cellular GnRH mRNA levels. We tested this hypothesis by comparing cellular levels of GnRH mRNA between ad libitum fed (n = 4) and starved (n = 4) adult male rats. Five days of starvation resulted in a 21% decrease in body weight and an 85% decline in serum testosterone levels (fed: 13.9 +/- 2.00 vs. starved: 2.1 +/- 0.70 nmol/l; p < 0.01). In situ hybridization and image analysis demonstrated that short-term starvation influenced neither GnRH cell number (fed: 148 +/- 16 vs. starved: 157 +/- 13 cells) nor cellular GnRH mRNA signal level (fed: 177 +/- 5 vs. starved: 160 +/- 7 grains/cell) in any region of the basal forebrain. Endogenous opioid peptides are known to exert an inhibitory effect on GnRH secretion and have been implicated in having a role in the starvation-induced effects on the reproductive system. We therefore also tested the hypothesis that alterations in proopiomelanocortin (POMC) gene expression are involved in the neuroendocrine response to starvation, by comparing cellular POMC mRNA levels in individual neurons (approximately 160 neurons/animal) of the arcuate and periarcuate nuclei between fed control (n = 4) and starved (n = 4) adult male rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous visualization of two cellular mRNA species in individual neurons by use of a new double in Situ hybridization method.

We present a new method for the simultaneous detection of two mRNA species within individual neurons. The technique involves the use of radio-labeled and digoxigenin-labeled cRNA probes, the application of which confers a high specificity and sensitivity to the in situ hybridization analysis. We demonstrate the use of this method by illustrating the coexpression of preprogonadotropin-releasing hormone (GnRH) mRNA and preprogalanin mRNA in neurons in the rat forebrain and report a distinct sexual dimorphism in galanin gene expression by GnRH neurons. Coupling this technology with semi-quantitative analysis of the mRNA species hybridized with the isotopically labeled mRNA would permit studies of gene regulation in individual cells among the heterogeneous populations of the brain.

Gonadotropin-releasing hormone messenger ribonucleic acid levels are unaltered with changes in the gonadal hormone milieu of the adult male rat.

Testicular function is regulated by the negative feedback effect of sex hormones acting at the brain and pituitary to inhibit the secretion of LH and FSH. An important component of this feedback axis is presumed to involve regulation of secretion and possibly synthesis of GnRH by the brain. We tested the hypothesis that the castration-induced increase in gonadotropin secretion is subserved, at least in part, by increased synthesis of GnRH. Using in situ hybridization and an oligonucleotide probe to pro-GnRH messenger RNA (GnRH mRNA), we compared the level of cellular GnRH mRNA and the relative number of GnRH mRNA-containing neurons between intact and 21-day castrate adult male rats. To derive estimates of the number of GnRH cells and the cellular GnRH mRNA content, coronal sections from each animal were anatomically matched between intact and castrate groups. All identifiable cells within these sections were counted and analyzed with the aid of a computerized image analysis system, by an observer unaware of the animal's experimental group and were assigned an anatomical location for reference. In an initial experiment, we observed no difference in cellular GnRH mRNA signal level between intact (n = 4) and castrate (n = 5) animals (129 +/- 8 vs. 139 +/- 5 grains per cell); however, we did find a statistical difference between the intact and castrated groups in the relative number of GnRH mRNA-containing cells (intact: 212 +/- 15 vs. castrate: 320 +/- 18). To confirm this observation, we repeated the experiment by again comparing the number of GnRH mRNA-positive cells between intact (n = 4) and castrate (n = 4) rats. In this second experiment, we found no difference in the number of identifiable GnRH mRNA-containing cells between intact and castrate animals (272 +/- 14 vs. 274 +/- 36, respectively); this was the case for the total cell count as well as when the data were analyzed by anatomical region. To clarify the conflicting results on cell counts of Exps 1 and 2, we repeated the experiment a third time, again comparing both the number of GnRH mRNA-containing cells and the cellular content of GnRH mRNA. In this experiment, we observed that neither cell number nor content of GnRH mRNA differed between the intact and castrate groups. Again, this was the case for total cell count, as well as when the data were analyzed by anatomical region.(ABSTRACT TRUNCATED AT 400 WORDS)

Pubertal changes in gonadotropin-releasing hormone and proopiomelanocortin gene expression in the brain of the male rat.

Pubertal development in mammals is in part attributable to a brain-dependent process, whereby increased pulsatile GnRH secretion leads to the awakening of the entire reproductive system. However, the brain mechanisms controlling this event are unknown. The apparent increase in GnRH secretion at puberty could reflect an autonomous change in the activity of GnRH neurons themselves or in the afferent networks leading to GnRH neurons. If there were a significant increase in the secretion of GnRH with puberty onset, we hypothesized that there would be a commensurate increase in the biosynthetic capacity of GnRH neurons to meet the increasing demand. We tested this hypothesis by comparing the level of cellular prepro-GnRH mRNA (GnRH mRNA) observed between prepubertal (25-day-old; n = 5) and adult (75-day-old; n = 4) male rats by in situ hybridization. We detected no significant change with puberty in GnRH mRNA signal levels in any of the anatomical areas examined, which included the vertical limb of the diagonal band of Broca, medial septum, lateral preoptic area, and medial preoptic area. Given the variance of our analytical technique, we determined that there was a greater than 90% probability that we would have detected a 20% increase in GnRH mRNA had there been one. Endogenous opioid peptides have been implicated in timing the onset of puberty in the rat, with the argument being that a loss in opioid tone could effect a disinhibition of GnRH secretion. One opioid peptide, beta-endorphin, is among several peptides cleaved from the precursor POMC. We hypothesized that with puberty, POMC neurons in the arcuate nucleus would have an attenuated capacity to produce beta-endorphin. We tested this hypothesis by comparing cellular pre-POMC mRNA (POMC mRNA) levels in the arcuate nuclei of prepubertal (n = 6) and adult (n = 7) male rats with in situ hybridization. We observed an increase in POMC mRNA levels with puberty; prepubertal rats had relative POMC mRNA signal levels of 119 +/- 10 grains/cell, while adult rats contained 167 +/- 12 grains/cell (P less than 0.02). This increase in cellular POMC mRNA was confined to the rostral portion of the arcuate nucleus. We conclude that the GnRH gene is fully expressed well before the time of normal puberty onset and that the increase in POMC mRNA that occurs with the onset of puberty may be important for the development of pulsatile GnRH secretion.

Turn taking in atypical conversations: the case of the speaker/augmented-communicator dyad.

Structural disturbances in conversation and their consequence for the distribution of control between partners were illustrated in a study investigating turn taking in dyads involving speech-handicapped individuals using alternative communication system (augmented or aided communicators) and normally speaking adults (unaided communicators or speakers). The turn-taking system in these atypical conversations differed from normal conversations in several ways. Interactants had to adapt to specific physical constraints on the interaction and compensated for these constraints by using "available" behaviors to signal turn exchanges. Augmented communicators were unsuccessful in interaction management as evidenced in the unaided communicators' unilateral control over them in turn regulation. Augmented communicators were frequently unsuccessful in their attempts to secure speaking turns, whereas unaided communicators were extraordinarily successful as compared with typical conversation. Implications for the understanding of normal and atypical interaction patterns and their relevance to conversational control are discussed.