The influence of intravenous magnesium sulphate on the occurrence of atrial fibrillation after coronary artery by-pass operation

To examine the influence of (Mg) on hypomagnesaemia and atrialfibrillation (AF) following coronary artery by-pass surgery,140 consecutive patients were randomized to receive 70 mmolof magnesium sulphate intravenously (n = 69) or placebo (n =71). Serum magnesium concentrations fell to 0.77 ± 0.10mmol. l^–1 in the control group but rose to 1.09 ±0.17 mmol. l^–1 in the Mg group (P <0.001). The incidenceof AF was 29% in the Mg group and 26% in the placebo group (NS).The AF patients were older, more of them had had prior AF episodes,their sinus rates (SR) were slower (78 ± 10 vs 86 ±12 beats. Min^–1; P <0.01) and serum Mg concentrationshigher (0.89 ± 0.21 vs 0.11 mmol. ^l–1; P <0.05)The incidence of AF was 43% in the highest quartile of serumMg and 23% among the rest (P = 0.056). In patients experiencingAF during the first three post-operative days, serum Mg concentrationswere higher and SR slower on each day compared with non-AF patients.SR increased post-operatively less with high Mg levels (P =0.044). In the Mg group, serum Mg and SR were the only independentpredictors of AF. In conclusion, the incidence of post-operativeAF is not decreased with magnesium. High Mg levels are likelyto provoke AF probably by mechanisms that modify SR.     

Phrenic Nerve Stimulation for Central Ventilatory Failure with Bipolar and Four-Pole Electrode Systems

A multi-channel phrenic nerve stimulator developed in Tampere has been implanted into seven patients with C2-tetraplegia and into three patients with central sleep apneas. Six bipolar cuff electrodes were implanted bilaterally into the neck. Two four-pole cuff and 14 four-pole noncuff electrodes were used in seven patients and to replace one bipolar electrode. Four-pole electrodes were implanted within the thorax. Seven patients achieved total independence from conventional ventilators within 4 months of implantation, and one for 18 hours each day. Two patients died 12 days and 3 months after implantation and two patients after having achieved independence from mechanical ventilators from causes unrelated to the stimulators. Reoperations were necessary because of dislocation of receivers, electrodes, electrode lesions, nerve injuries, and technical failures in seven patients. Most of the problems appeared in two patients with obesity and in three patients with very thin phrenic nerves. Single unit prototypes failed technically more frequently than units of prototype serial fabrication. New electrode design, progress in the manufacture of receivers, and improved implantation technique should help to diminish failures in future.     

Modern Methods for Reliable Preoperative Localization of Insulinoma

A case of insulinoma is reported in which the correct localization of tumor was made with PTP and immunoreactive insulin values from the portal venous system and in which pancreas angiography indicated a false positive tumor localization. PTP should be done to every patient to confirm the preoperative location of the insulinoma(s).     

COMMENTS

Glial-cell-line-derived neurotrophic factor (GDNF) is a distant member of the transforming growth factor superfamily. It binds to and activates a receptor complex consisting of GFR-α1 and Ret receptor tyrosine kinase. In testis, GDNF is expressed by Sertoli cells. We have shown by transgenic loss- and gain-of-function mouse models that GDNF regulates the cell fate decision of undifferentiated spermatogonia. In the GDNF +/− mice, the spermatogonia differentiate in excess leading to the depletion of germ cells. In the mice overexpressing GDNF in testes, undifferentiated spermatogonia accumulate in the tubules, no sperm is produced, and the mice are infertile. After a year, the GDNF overexpressing mice frequently (89%) develop testicular tumours, and most of them are bilateral (56%). All these tumours show the same histological pattern. They are composed of round spermatogonial/gonocytic cells with only a scant cytoplasm. The tumours are locally invasive but do not metastasise. They express germ line markers, are positive for alkaline phosphatase, and aneuploid with a triploid peak. Thus, by several histological, molecular, and histochemical characteristics, the GDNF-induced tumours mimic classical seminomas in men, but the precursor lesions are apparently different in mouse and man.     

Effects of 2-Ethylhexanoic Acid on Reproduction and Postnatal Development in Wistar Rats

Reproductive toxicity of 2-ethylhexanoic acid (2-EHA) was studiedin Wistar rats. The animals (24 animals per sex per group) weregiven 2-EHA as a sodium salt in drinking water at daily dosesof 100, 300, or 600 mg/kg. Control animals received plain water.Male rats were exposed to 2-EHA for 10 weeks and females for2 weeks prior to mating, both sexes during the mating periodand females during the entire gestation and lactation period.2-EHA caused a slight but dose-dependent decrease in fertility;time to mating increased at 300 and 600 mg/kg and even totalinfertility ensued. 2-EHA slightly decreased sperm quality inmales. The spermatozoa were significantly less motile at 100and 600 mg/kg and abnormal sperm occurred more frequently atthe two highest dose levels. The average litter size was reducedby 16% in the dose group receiving 600 mg/kg. The birth weightsof the pups were unaffected but the body weight gain was transientlyslower during lactation at 600 mg/kg. Several pups appearedabnormal (kinky tail, lethargic, slightly paralyzed legs) andthe physical development assessed by several landmarks (openingof eyes, eruption of teeth, hair growth) and reflexes (gripreflex, cliff avoidance) was delayed at 300 and 600 mg/kg. Inanother experiment, a single dose of 600 mg/kg 2-EHA was givento pregnant females by gavage on Gestational Day 4, 5, 6, or7 and the number of implantations were counted on GestationalDay 10. Administration on Day 6 decreased the number of implantationsand caused resorptions. In conclusion, 2-ethylhexanoic acidcaused impaired fertility in Wistar rats and delayed postnataldevelopment of pups. The reduced fertility might result fromdisturbed implantation in uterus and the retarded developmentof pups from teratogenicity and pre- and postnatal toxic effectsof 2-EHA.     

Morbid Obesity,Gastric Plication and a Severe Neurological Deficit

ABSTRACT. SomerH, BergstrÖm L, Mustajoki P, Rovamo L. (Department of Neurology, Third Department of Internal Medicine and Children's Hospital, University of Helsinki, Helsinki, Finland.) Morbid obesity, gastric plication and a severe neurological deficit. A 39-year-old man had protracted vomiting after gastric plication for morbid obesity. Within three months he lost 53 kg in weight and developed neuromuscular weakness, especially in the lower extremities. Clinical and laboratory studies suggested both radicular and peripheral neuropathy. One year later the condition was only marginally improved: he took only few steps unsupported. The apparent etiology is malnutrition but the primary cause remained unknown.     

Reversal of Atrial Remodeling after Cardioversion of Persistent Atrial Fibrillation Measured with Magnetocardiography

Background : Atrial fibrillation (AF) causes electrical, functional, and structural changes in the atria. We examined electrophysiologic remodeling caused by AF and its reversal noninvasively by applying a new atrial signal analysis based on magnetocardiography (MCG).
Methods : In 26 patients with persistent AF, MCG, signal-averaged electrocardiography (SAECG), and echocardiography were performed immediately after electrical cardioversion (CV), and repeated after 1 month in 15 patients who remained in sinus rhythm (SR). Twenty-four matched subjects without history of AF served as controls. P-wave duration (Pd) and dispersion (standard deviation of Pd values in individual channels) and root mean square amplitudes of the P wave over the last 40 ms portions (RMS40) were determined.
Results : In MCG Pd was longer (122.8 ± 18.2 ms vs 101.5 ± 14.6 ms, P < 0.01) and RMS40 was higher (60.4 ± 28.2 vs 46.9 ± 19.1 fT) in AF patients immediately after CV as compared to the controls. In SAECG Pd dispersion was increased in AF patients. Mitral A-wave velocity and left atrial (LA) contraction were decreased and LA diameter was increased (all P < 0.01). After 1 month, Pd in MCG still remained longer and LA diameter greater (both P < 0.05), while RMS40 in MCG, Pd dispersion in SAECG, mitral A-wave velocity, and LA contraction were recovered.
Conclusions : Magnetocardiographically detected atrial electrophysiologic alterations in persistent AF diminish rapidly although incompletely during maintained SR after CV. This might be related to the known early high and late lower, but still existent tendency to AF relapses.     

Cardiac Amyloidosis

ABSTRACT. Two male patients with primary cardiac amyloidosis are described. Patient 1 presented with typical effort angina pectoris with no ischemic electrocardiographic changes and a normal coronary angiogram. At necropsy, a severe diffuse, intravascular amyloid deposition was observed in the intramural coronary arteries. In patient 2 the presenting symptom was congestive heart failure with echocardiographic evidence of asymmetric septal hypertrophy and pericardial effusion. Technetium-99m pyrophosphate scintigraphy showed diffuse myocardial uptake, and the diagnosis of cardiac amyloidosis was confirmed in the postmortem examination. The diagnostic and therapeutic problems associated with cardiac amyloidosis are discussed in the light of these case reports.     

Frequency of initial caries lesions as predictor of future caries increment in children

Abstract — The aim of this study was to evaluate the predictive power of the frequency of initial caries lesions in selecting persons at high risk for caries. The subjects ( n = 124) were 11–13 yr old at the beginning of the follow-up. Caries was registered initially and after 5 yr. Evaluation of the predictions was based on cross-tabulations of the subjects according to their predicted caries risk and the actual 5-yr caries increment. Logistic regression analyses were used to produce the individual risk scores. In addition to the caries scores, age of the subjects, was included in the prediction function. In bivariate analyses the total initial caries score at baseline correlated better with caries increment than FS and DS scores did (r = 0.40, 0.13, and 0.31, respectively). When past caries experience was used as predictor, 69% of the children were classified correctly into the low and high risk groups. Surprisingly, only two more subjects (2%) were classified correctly when initial caries score was included in the function. These results suggest that inclusion of initial caries score adds little to the predictive power of the conventional DS and FS scores.     

Pain and activity disturbance after paediatric day case adenoidectomy

Over the past two decades outpatient surgery has become standard practice in paediatric surgery. Adenoidectomy is a common surgical procedure in children. In this prospective survey pain and pain-related outcomes such as sleep and activity disturbance were evaluated in 167 children aged 1–7 years who had undergone adenoidectomy as a day case in Kuopio University Hospital. The survey questionnaire consisted of 76 structured questions about pain, pain medication, adverse effects and daily activities during first week after the operation. Eighty-three per cent of children had pain at home and 17% of them had moderate or severe pain on a four point verbal rating scale. Eighty per cent of children used pain medication at home. Pain medication did not cause any major adverse effects. Over 90% of children were back to normal daily activities during the first three postoperative days and nearly all were able to drink during the whole postoperative period. We conclude that pain is a common problem after adenoidectomy in children but most of the children return to normal activities within three days.