CT-Scanning of the cochlea in Pendred's syndrome*

The inner ears of 5 adult patients with Pendred's syndrome were investigated using a Siemens SOMATOM DRG. Five normal hearing adults participated in the investigation as a control group. The CT-scanning comprised 10-15 consecutive scans of the cochlea. The CT evaluation was performed using both a special bone setting and a soft tissue setting. The cochlear content was quantitatively evaluated by drawing an irregular region of interest on the bone pictures. The region of interest was then transferred to the soft tissue pictures by means of the standard program of the CT-scanner. The resulting mean values of attenuation expressed in Hounsfield Units were significantly lower in the Pendred cochleas was demonstrated in all patients with Pendred's syndrome. The lower values of attenuation of the cochlea in Pendred's syndrome reflect the rudimentarily developed infra-cochlear osseous structures in this disease. We conclude that CT-scanning of the cochlea using this procedure is reliable enough to replace the conventional axial-pyramidal tomography when a Mondini cochlea is suspected.     

Effects of sympathetic inhibition on blood pressure and renal responses to central hypervolaemia in normal humans

The purpose of this study was to evaluate the effects of short-term sympathetic inhibition with clonidine on blood pressure and renal responses to central hypervolaemia induced by thermoneutral head-out water immersion. Eleven healthy subjects were randomly studied on two occasions, during a 1 h pre-immersion period, 2 h of water immersion and a 1 h post-immersion period, after either placebo or clonidine treatment. Clonidine caused a significant suppression of plasma adrenaline, plasma noradrenaline, urinary noradrenaline excretion and mean arterial blood pressure. Blood pressure remained constant during water immersion after both placebo and clonidine, compared with the respective pre-immersion control values. The suppression pattern of plasma catecholamines and urinary noradrenaline in response to water immersion during placebo was similar after clonidine treatment. Renal volume excretion was not affected by clonidine. In contrast, clonidine caused a significant attenuation of the immersion-induced stimulation of natriuresis (maximum -33±12%, P<0.01, compared with placebo). These data indicate that the renal capacity to excrete sodium is impaired during moderate blood pressure reduction by short-term sympathetic inhibition with clonidine, whereas the regulation of arterial blood pressure in response to central hypervolaemia is maintained.     

Selected Trace Elements and Proteins in Serum of Apparently Healthy Newborn Infants of Mothers Who Smoked during Pregnancy

ABSTRACT. The serum concentrations of selected trace elements and proteins in cord blood from 17 new-bom infants whose mothers were habitual smokers were compared with values from 22 infants of non-smoking mothers. All the mothers were healthy with normal pregnancies and deliveries. Cigarette smoke exposure was verified by determinations of nicotine, cotinine and thiocyanate concentrations in cord blood. Infants of smoking mothers had a slightly lower mean birth weight (3490±430 g) than control infants (3780±460 g). Infants of smokers had lower serum iron ( p =0.05) and prealbumin ( p ≤0.05), but higher serum copper ( p ≤0.05) and ceruloplasmin ( p ≤0.01) levels than the controls. Infants of smoking mothers tended to have higher levels of the acute-phase reactants alpha-₂-macroglobulin and orosomucoid, but lower levels of albumin, transferrin and retinol-binding-protein, although differences were not statistically significant.     

In Vitro Development of Bone-Marrow-Derived Macrophages Influence of Mouse Genotype on Response to Colony-Stimulating Factors and Autocrine Interferon Induction

Responsiveness to granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage CSF (M-CSF) of bone marrow cells derived from different mouse strains was investigated. There were great variations in proliferation between different strains of inbred mice. Bone marrow cells from mouse strains with a high rate of proliferation in response to GM-CSF also had a high proliferating capacity to M-CSF. The response to either CSF did not correlate with a certain H-2 haplotype. GM-CSF induced consistently higher proliferation than M-CSF. Proliferation in response to M-CSF, but not to GM-CSF, could be enhanced by the addition of antibodies against interferon (IFN). IFN is the only known inducer of (2'-5') oligoadenylate (oligo (A] synthetase. This enzyme was induced in macrophages grown in the presence of M-CSF, but not in GM-CSF promoted cells. Enzyme induction was completely abrogated by simultaneous treatment with anti-IFN alpha/beta. Infection of macrophages with herpes simplex virus type 1 (HSV) and vesicular stomatitis virus (VSV) revealed that GM-CSF-promoted cells were highly susceptible to lytic infection by these viruses. In contrast, virus titres in M-CSF-cultured cells were 100-fold lower. We conclude that, contrary to M-CSF, GM-CSF does not induce autocrine IFN during haematopoiesis. As judged from data with BALB/c mice, the sensitivity to the anti-proliferative effect of the autocrine IFN may be a factor which influences M-CSF-promoted proliferation.     

Yersuche über mikrochemische Reaktionen.

• 1 Die fällende Wirkung von Sulfosalizylsäure und Lanthannitrat auf Eiweiss, Nucleinsäure und Eiweiss-Nucleinsäuregemische bei verschiedenen Wasserstoffionenkonzentrationen wurde quantitativ untersucht. Es wurde gezeigt, dass, während Eiweiss von Sulfosalizylsäure, Nucleinsäure von Lanthannitrat (aber nicht umgekehrt) gefällt wurden, Eiweiss-Nucleinsäure-Gemische mit beiden Reagentien Fällungen gaben.
• 2 Mit gepufferten Lösungen von Sulfosalizylsäure und Lathannitrat konnte gezeigt werden, dass rote Blutkörperchen von Eidechsen in einem gewissen Funktionsstadium, das möglicherweise mit der Zellteilung zu tun hat, eiweissfreie oder sehr eiweissarme Zellkerne hatten, während die Zellkerne der eigentlichen Zellteilungsprozesse stark eiweisshaltig waren.

     

Rate-Responsive Pacing by Means of Activity Sensing Versus Single Rate Ventricular Pacing: A Double-Blind Cross-Over Study

The clinical appiicabiJity of rate-responsive pacing (RRP) by means of activity sensing has been tested in 15 patients. The patients (ages 24–85) had sinus node dysfunction (2), atrial fibrillation (7), or sinus rhythm (6) combined with complete atrioventricular block. Exercise capacity was investigated on a bicycle ergometer and on a treadmill in a double-blind cross-over study design following one week each of fixed rate ventricu/ar pacing (70 bpm) and rate-responsive pacing (60/125–150 bpm). The patients answered a questionnaire concerning subjective symptoms. A Holter ECG was recorded during 24 hours of all day activity on rate-responsive pacing. During exercise in the rate-responsive mode, heart rate increased more on the treadmill than on the bicycle. A majority of the patients (13 of 15) preferred rate-responsive pacing mainly due to less dyspnea and tiredness. Exercise capacity improved significantly both on bicycle (+7%; p < 0.01) and on treadmill (+19%; p < 0.01) during rate-responsive pacing. There were no complications during the follow-up period. In conclusion, the activitysensing pacemaker is a valuable supplement to existing types o/ pacemakers. It should be used in patients in whom an atrial electrogram cannot be used for rate triggering.     

Craniofacial growth in bone marrow transplant recipients treated with growth hormone after total body irradiation

Abstract— The effect of growth hormone (GH) treatment on craniofacial development was studied in five children exhibiting growth retardation following bone marrow transplantation. Linear and angular measurements were made on lateral radiographic cephalograms taken prior to the start of GH treatment and after an average treatment time of 1.2 yr. The results showed that the mean growth increments of mandibular length in the GH treated children, exceeded the corresponding values of the control group by 150% during the period of investigation. It is suggested that this dimensional increase in the patients was due to GH stimulation on the chondral growth process in the mandibular condyles.