THE SEMI-PROPORTIONAL HAZARDS MODEL REVISITED: PRACTICAL REPARAMETRIZATIONS

Reformulations of the semi-proportional hazards model are outlined making estimation and testing of stratum-covariate interaction effects easily accessible within the framework of the stratified Cox proportional hazards model. The method is illustrated by a practical analysis of variables influencing bronchial responsiveness with data from the Hordaland study of obstructive lung disease.     

Tyrosine kinase mutations in gastrointestinal stromal tumors in a nation‐wide study in Iceland

Tryggvason G, Hilmarsdottir B, Gunnarsson GH, Jónsson JJ, Jónasson JG, Magnússon MK. Tyrosine kinase mutations in gastrointestinal stromal tumors in a nation‐wide study in Iceland. APMIS 2010; 118: 648–56. Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. It is characterized by activating mutations in the tyrosine kinase genes c‐kit or PDGFRA. This study examined the mutation rate and type in a population‐based material. All gastrointestinal mesenchymal tumors over the years 1990–2004 were evaluated and GIST tumors identified using immunohistochemistry (c‐kit) and conventional pathologic parameters. Paraffin sections from all tumors were subjected to mutation analysis on exons 9, 11, 13 and 17 of the c‐kit gene and exons 12 and 18 of the PDGFRA gene. To screen for mutations, we used a highly sensitive conformation‐sensitive gel electrophoresis (CSGE) and to define the mutated alleles, we employed direct automated DNA sequencing. All c‐kit‐positive gastrointestinal mesenchymal tumors were entered into the study. Fifty‐six tumors from 55 patients were analyzed. Mutations were found in 52 tumors representing a 92.9% mutational rate. Most of the mutations were found in c‐kit exon 11 (76.8%), followed by c‐kit exon 9 (10.7%). PDGFRA mutations were only found in three tumors. No correlation of mutation type with biologic behavior was found. This population‐based study, using a sensitive CSGE method, identifies mutations in the great majority of patients with GIST.     

Follow-up of the Antibody Response to Measles Vaccine in a Rural Area of Guinea-Bissau

ABSTRACT. One hundred and fourty-four children who either were already immune or had been successfully immunized against measles were reexamined after 16 months. All still had circulating Elisa antibodies at a clearly detectable level. Titres were higher in the group of children stated to have had measles prior to the immunization. None of the children had measles after immunization. Boostering by the wild virus may have occurred, whereas no evidence of a booster effect from the vaccine was found. About one third of the children were underweight. Plasmodium falciparum parasitaemia rate, and also its seasonality, varied with the location of the child's homestead. Even children exposed to mesoendemic P. falciparum malaria and moderate malnutrition can be successfully immunized with a conventional live attenuated measles vaccine from 8 months of age, which probably results in a lasting protection.     

ACUTE POISONINGS OF CHILDREN IN OSLO

ABSTRACT. A one year prospective study of all children under 15 years of age presenting for acute poisoning in Oslo is reported. There were 181 admissions in 179 children, of which 97 (54 %) were boys, giving an annual incidence of 2.3 %. All children survived without sequelae. Most poisonings were accidental and only two suicidal attempts were recorded. Of all poisonings 68 per cent occurred between the age of 1 and 2 years. The dominating toxic agents were drugs (44 %), tobacco (22 %) and petroleum products (9 %). Most poisonings were mild and only 7 (4 %) classified as severe. Seventy-two per cent of all children were admitted within the second hour after the ingestion of the toxic agent. Therapy should therefore be directed towards emptying the stomach with emetics or gastric lavage, unless corrosives or petroleum products are ingested. Childhood poisonings still call for better preventive measures since the toxic agent was found inappropriately stored in 86 % of the accidental poisonings.     

PAROXYSMAL TACHYCARDIA IN INFANCY AND CHILDHOOD I. Paroxysmal Supraventricular Tachycardia

A 1 to 30 year follow-up study of 54 infants and children with paroxysmal supraventricular tachycardia is presented. In 28 cases the first attack occurred in infancy, and in 18 of these already in the first months of life. Nine patients had organic heart disease. The WPW syndrome was diagnosed in 30 cases. When first seen, most of the infants presented signs of incipient or manifest congestive heart failure, which was very unusual in the children, most of whom had only minor symptoms. Four children had experienced brief syncopes during attacks. Digitalis was effective against congestive heart failure and, when continued, may have prevented failure during subsequent attacks. Whether digitalis and other anti-arrhythmic agents facilitated conversion to sinus rhythm could not be established in this study. Vagal stimulation was only rarely effective. Preventive treatment with digitalis or other antiarrhythmic drugs seemed to have little if any effect on the frequency of recurrent attacks. Out of 23 infants who were followed for at least 5 years, 17 had been free from attacks during the last 3 years and 13 of these had had their last attack before the age of 6 months. Out of 23 children followed for 5 years or more, only 3 had been free from recurrences during the last 3 years. Patients with the WPW-syndrome had a somewhat higher incidence of recurrent attacks.     

PENTAZOCINE AND PHENAZOCINE: A Double-Blind Comparison of Two Benzomorphan Derivatives in Postoperative Pain

The analgesic effeas of intramuscular injections of 30 and 45mg pentazocine (Win 20, 228) were compared with 2 and 3 mg phenazocine(Narphen) in 128 patients with pain following abdominal surgery.Well-matched pairs of patients were allocated randomly to drugs.Pain was assessed under double-blind conditions, patients' assessmentsof relief were noted and vital capacity measurements were made.Both drugs were efficient for the relief of postoperative painand did not cause nausea or vomiting. On average, 38 mg Win20,228 was analgesically equivalent to 2.6 mg phenazocine. Changesin vital capacity gave a good indication of postoperative painrelief after both upper and lower abdominal operations. Thesechanges were found to be significantly correlated with vitalcapacity before injection. ^*Statistician, Bayer Products. Present address: Glaxo LaboratoriesLtd., Ulverston, Lanes.     

Central cardiovascular and oxygen variables during haemorrhage in the pig

Background: We evaluated the ability of the standards issued by the Danish Society of Anaesthesiologists to reflect a blood loss.
Methods: In 9 pigs bled (0–24 ml kg^-1) and retransfused (to 28 ml kg^-1) during halothane anaesthesia, central cardiovascular, thoracic electrical impedance (TI), oxygen, acid-base and temperature variables were recorded.
Results: With the recommendation for minor surgery (mean arterial pressure (MAP) and heart rate (HR)), the correlation to the blood loss was 0.74 ( P < 0.001) and with that for major surgery (MAP, HR, central venous pressure (CVP) and rectal temperature (Temp_r)) it was 0.79 ( P < 0.001). With the recommendation for extensive surgery (MAP, HR, CVP, pulmonary artery catheter variables and the central-peripheral temperature difference (ΔTemp_r-t)), the correlation was 0.84 ( P < 0.001). Non-invasive monitoring (MAP, HR, ΔTemp_r-t TI and near-infrared spectroscopy of the brain (S_invosO₂)) was only slightly better than basal monitoring (r=0.76, P < 0.001). However, adding arterial base excess (BE), TI and peripheral temperature (Temp_t) to the recommendation for major surgery resulted in a correlation of 0.87 ( P < 0.001), while adding BE and TI to the recommendation for extensive surgery raised correlation to only 0.88 ( P < 0.001).
Conclusion: When the recommendations were followed the correlation to the blood loss ranged from 0.74–0.84. However, with the recording of MAP, HR, CVP, ΔTemp_r-t, BE and TI a correlation of 0.87 was achieved, indicating that a pulmonary artery catheter may not be in need for patients undergoing surgical procedures with expected haemorrhage.     

Training in Controlled Drinking for Early-stage Problem Drinkers

Forty-eight early-stage problem drinkers were recruited through a newspaper announcement and randomly assigned to one of four outpatient treatment groups: (1) Bibliotherapy- Behavioral Self-Control Training (BSCT), (2) BSCT-therapist directed, (3) Training in Coping Skills and (4) a combination of BSCT and Coping Skill Training. The weekly alcohol consumption in all groups decreased significantly from intake to 3, 6 and 12 month follow-up. There were no significant differences among the groups. At the same time the number of life problems decreased significantly. The majority of the clients reduced their alcohol consumption during the assessment period, before treatment started. The absence of a non-treatment control group means that we cannot be sure about the reasons for this early change. Theoretical implications of these results are discussed.