The alveolar-arterial difference in oxygen tension increases with temperature-corrected determination during moderate hypothermia

Moderate hypothermia (32-33 degrees C) occurs in anesthetic practice. However, intrapulmonary gas exchange and the effect of temperature correction of blood gases on oxygen and carbon dioxide exchange have not been investigated in these patients. We investigated alveolar-arterial difference in oxygen tension (AaDO2) and arterial to end-tidal difference in carbon dioxide (Pa-ETCO2) during rewarming of eight ASA physical status I patients from hypothermia of 32 degrees C. Anesthesia was maintained with fentanyl/propofol. AaDO2 and Pa-ETCO2 were assessed by analyzing arterial blood gases and saturated water vapor pressure, uncorrected or corrected to actual body temperature. The respiratory quotient (RQ) was measured by calorimetry. After temperature correction of blood gases and water vapor pressure, the AaDO2 was significantly higher at 33 and 32 degrees C compared with 36 degrees C (56 +/- 13 and 64 +/- 14 vs 39 +/- 10 mm Hg; P < 0.05 and P < 0.01). The deterioration of pulmonary oxygen exchange was not detected if arterial blood gases and water vapor pressure were not corrected. The RQ did not change during moderate hypothermia compared with 36 +/-C. The temperature-corrected Pa-ETCO2 was not affected by hypothermia. We conclude that AaDO2 is increased during moderate hypothermia. This is only detected when water vapor pressure and arterial blood gases are corrected to actual body temperature.

IMPLICATIONS

We investigated intrapulmonary oxygen and carbon dioxide exchange during moderate hypothermia (32 degrees C) in eight patients. If oxygen, carbon dioxide, and water vapor pressure were corrected to actual body temperature, the alveolar-arterial oxygen tension difference was increased during hypothermia. The carbon dioxide tension difference and the respiratory quotient were unaffected by hypothermia.

CD1d-restricted immunoglobulin G formation to GPI-anchored antigens mediated by NKT cells

Immunoglobulin G (IgG) responses require major histocompatibility complex (MHC)-restricted recognition of peptide fragments by conventional CD4(+) helper T cells. Immunoglobulin G responses to glycosylphosphatidylinositol (GPI)- anchored protein antigens, however, were found to be regulated in part through CD1d-restricted recognition of the GPI moiety by thymus-dependent, interleukin-4-producing CD4(+), natural killer cell antigen 1.1 [(NK1.1)+] helper T cells. The CD1-NKT cell pathway regulated immunogobulin G responses to the GPI-anchored surface antigens of Plasmodium and Trypanosoma and may be a general mechanism for rapid, MHC-unrestricted antibody responses to diverse pathogens.

Treatment of distal femoral fractures with intramedullary supracondylar nails in elderly patients

30 acute fractures of the distal femur in 29 elderly patients were treated with a Russell-Taylor intramedullary supracondylar nail (IMSC). 26 of the 30 fractures (87%) united in 2-8 months. Two patients died before fracture union for reasons unrelated to the fracture. Two patients were reoperated upon, in one case the fracture was not adequately reduced at the first operation; in the other patient the nail broke 4 months after operation. In all patients knee flexion reached at least 90 degrees. No infections or thromboembolic complications were seen. The IMSC nail provided the necessary stable fixation with only a few complications in this group of elderly patients without the need to prolonged immobilisation.

The rat Subcutaneous Air Sac model: a quantitative assay of antiangiogenesis in induced vessels

A new in vivo experimental model--the Subcutaneous Air Sac (SAS) model-has recently been presented to replace a previous in vivo rabbit cornea assay where neovascularisation was induced by chemical injury of the cornea or by implantation of tumour cells intracorneally, a methodology which is believed to cause severe pain to the animals. In the SAS model, an air sac is induced by injection of air subcutaneously on the back of the animal. After 10-14 days the air sac appears as an almost transparent avascular membrane in which induction of new vessels can be studied. We present recent developments of this technique: In the SAS-tumour technique, vascular endothelial growth factor-producing tumour cells are inoculated subcutaneously directly on the membrane, and the formation of new vessels is measured 8 days later. In the SAS-pellet technique, slow-release pellets containing angiogenic factors, basic fibroblast growth factor or vascular endothelial growth factor are implanted on the subcutaneous membrane by a simple operation. The formation of new vessels is measured 10 days later. The ability of the SAS-tumour- and SAS-pellet techniques to detect an antiangiogenic effect of a systemically administered compound was investigated using the fumagillin analogue TNP-470 (o-chloroacetyl-carbamoyl)-fumagillol) as a positive control given subcutaneously for 7 and 9 days, respectively. At a dose of 10 mg TNP-470/kg/day the angiogenesis was reduced by approximately 70% in the SAS-tumour technique and by 40-60% in the SAS-pellet technique. The animals were unaffected by the SAS methodology. The SAS-tumour and SAS-pellet models are considered complementary and make use of simple and almost similar techniques which facilitate the evaluation.

Molecular evolution of a sex determination protein. FEM-2 (pp2c) in Caenorhabditis

Somatic sex determination in Caenorhabditis elegans involves a signal transduction pathway linking a membrane receptor to a transcription factor. The fem-2 gene is central to this pathway, producing a protein phosphatase (FEM-2) of the type 2C (PP2C). FEM-2 contains a long amino terminus that is absent in canonical PP2C enzymes. The function of this domain is difficult to predict, since it shows no sequence similarity to any other known proteins or motifs. Here we report the cloning of the fem-2 homologue from Caenorhabditis briggsae (Cb-fem-2). The sequence identity is much higher than that observed for other C. briggsae homologues of C. elegans sex determination proteins. However, this level is not uniform across the entire lengths of the proteins; it is much lower in the amino termini. Thus, the two domains of the same protein are evolving at different rates, suggesting that they have different functional constraints. Consistent with this, Cb-FEM-2 is able to replace some, but not all, of the Ce-FEM-2 in vivo function. We show that removal of the amino terminus from Ce-FEM-2 has no effect on its in vitro phosphatase activity, or its ability to replace the in vivo function of a yeast PP2C enzyme, but that it is necessary for proper FEM-2 function in worms. This demonstrates that the amino terminus is not an extended catalytic domain or a direct negative regulator of phosphatase activity.

Suxamethonium-induced cardiac arrest and death following 5 days of immobilization

The present report describes a case of cardiac arrest and subsequent death as a result of hyperkalaemia following the use of suxamethonium in a 23-year-old Malawian woman. Five days after the onset of the symptoms of meningitis, the patient aspirated stomach contents and needed endotracheal intubation. Forty seconds after injection of suxamethonium, bradycardia and cardiac arrest occurred. Attempts to resuscitate the patient were not successful. The serum level of potassium was observed to be 8.4 mequiv L-1. Apart from the reduction in the patient's level of consciousness, there were no signs of motor neurone damage or of any of the other known predisposing conditions for hyperkalaemia following the administration of suxamethonium. It is postulated that her death was caused by hypersensitivity to suxamethonium, associated with her 5-day immobilization.

Capital budgeting techniques

The cost of new medical imaging equipment for a radiology practice is a major capital purchase. Due to rapid advances in technology and imaging techniques, the management decision to purchase new capital equipment can present itself every few years. The present report explains various financial management techniques that are generally used by corporations worldwide to determine their cost of capital. The cost of capital is the return on a capital investment project required by the providers of the capital. The published financial accounts of Sonic Healthcare Limited, Australia's largest pathology company, are reproduced as a numerical example of how the financial accounts of a business may be used to determine its cost of capital. The cost of capital forms an integral part of management's financial decision-making process.

Are causes of death predictable?

A random sample of death records of adult males from 1967 to 1970 was chosen from the South Australian Registry of Births, Deaths, and Marriages. The natural parents of these individuals were identified by cross-reference to birth certificates, and an extensive search was made of the death records for these parents. In this manner random families were selected for which, where possible, the cause of death and length of life of each family member were determined. From the information pertaining to the stated cause of death, each individual was assigned to one of five death categories.

Pyospermia and preterm, prelabor, rupture of membranes

OBJECTIVES

To investigate the possible association between presence of clinically unrecognized, specific genito-urinary tract microorganisms in men and preterm, prelabor rupture of membranes (PPROM) in their spouses.

STUDY DESIGN

Case control study. Eleven couples with PPROM were enrolled in the case group and 18 couples with normal pregnancies in the control group. For each man, samples of urine and semen were collected and a urethra swab was obtained. Microbiological assessment included, for each woman, cultures from vagina/cervix, urine and placenta. A smear from the vagina was obtained.

RESULTS

In the case group, pyospermia was found in three men. Two of these men, as well as their spouses, were Chlamydia trachomatis positive, and in the third man no microorganisms could be detected. None of the controls had pyospermia (p = 0.045). Among the eight cases without pyospermia one man and one women with Chlamydia trachomatis was found, but their spouses were negative. In the control group, no Chlamydia trachomatis was detected (p = 0.014). Among the women two cases and one control had positive culture of Group B streptococci (NS).

CONCLUSION

We suggest that the genital microflora of the man is associated with PPROM.

[Intrauterine growth retardation and premature delivery. The effect of smoking and psychosocial factors]

The purpose of the study is to investigate the influence of psychosocial stress, maternal schooling, social support, psychological well-being, alcohol and smoking on intrauterine growth retardation and premature delivery. At a Copenhagen university hospital 2432 consecutive Danish-speaking women in 20th week of pregnancy completed a questionnaire including the General Health Questionnaire and Severity of Psychosocial Stressor Scale and questions about social network, education, smoking and drinking habits. In 212 cases (8.7%) the women delivered before day 259 of gestation. In a multiple logistic regression model, pre-term delivery proved to be associated with psychosocial stress and poor school education. In 152 cases (6.3%) infants had a birth weight below the defined 10th percentile. In a multiple logistic regression model, IUGR was associated with smoking. In preventive programmes, such as anti-smoking campaigns, it should be kept in mind that women who smoke are also the least educated and have the poorest support from a social network.

Halothane-propofol anaesthesia for tracheal intubation in young children

In this double-blind, randomized study, we have investigated 100 healthy children, aged 3-6 yr. We compared intubating conditions and cardiovascular changes during light halothane anaesthesia and propofol 3 mg kg-1 with those during deep halothane anaesthesia. Light halothane anaesthesia was defined as an end-tidal concentration of 1%, deep halothane anaesthesia as 2%. Intubating conditions were graded according to ease of laryngoscopy, vocal cord position and coughing. There were no statistically significant differences in the assessment of intubating conditions between the two groups; 94% of the children in the 1% halothane-propofol group and 100% of the children in the 2% halothane group had acceptable intubating conditions. Systolic arterial pressure decreased by 13% in the 1% halothane-propofol group compared with 20% in the 2% halothane group (P < 0.01).

[PCDD/F-content in house dust]

The levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were determined in house dust samples collected from 22 residential houses located in different areas of Germany. Nine houses were located in an urban and industrial area, one house in a rural and 10 houses in a contaminated residential area near to a former metal reclamation plant. Two house dust samples were collected from two old farm houses, in which large amounts of pentachlorophenol (PCP) containing wood preservatives had been used several years ago. All dust samples were collected from the dust bags of vacuum cleaners and passed through a sieve (mesh: 2.0 mm). Particles < 2.0 mm were used for analysis. The average level of PCDD/F in "normal" house dust was 101 ng I-TEq/kg (range: 7.83-332 ng I-TEq/kg). The predominant congeners and chlorohomologues were OctaCDD followed by HeptaCDD, HeptaCDF and OctaCDF. The average level of PCDD/F in house dust samples collected from a contaminated residential area was 265 ng I-TEq/kg (range: 29.9-1050 ng I-TEq/kg). When compared with "normal" residential houses significantly increased levels of lower chlorinated PCDD/F were noted in the house dust samples from this area. The house dust samples collected from a PCP-treated old farm house were found to contain 1.39 and 11.8 micrograms I-TEq/kg. The chlorohomologues patterns were typical for PCP contaminated with PCDD/F. The present study shows that the levels of PCDD/F in house dust may be used as indicators of indoor contamination by PCDD/F and as reference values for further investigations.

The National Workshop to Develop the Chiropractic Research Agenda

OBJECTIVE

To convene a national meeting to develop a research agenda for the chiropractic profession that targets the need to increase chiropractic's research capacity.

DESIGN

The project was funded by a contract between the U.S. Health Resources and Services Administration Bureau of Health Professions (HRSA BHPr) and Palmer College of Chiropractic. Groundwork was established through a literature review and creation of position papers by teams of recognized authorities on the current status and recommendations for the future on the topics of clinical, educational, outcomes, basic science, and health services research and research infrastructure in chiropractic. The workshop took place July 12-14, 1996, in Washington, DC, with participants representing relevant segments of the research community of the health care professions, health professions education, health care policy, and all portions of the chiropractic community, including researchers, practitioners, faculty, administrators, and members of professional organizations. Work groups in each of the five target areas developed recommendations based on the seed material presented in the position papers. The results were incorporated into the final position papers.

RESULTS

The primary outcome of the workshop was the completion of five position papers, one for each of the topics addressed. Also, a consensus process was initiated at the workshop on infrastructure needs of the profession but, because of the diversity of experience and opinions and the broad scope of the topic, was not completed by the end of the project year.

CONCLUSIONS

Consensus was not reached on the development of a research agenda for the chiropractic profession, and a continuation of the contract has been agreed upon by HRSA BHPr to continue the process for another project year.

Deep halothane anaesthesia compared with halothane-suxamethonium anaesthesia for tracheal intubation in young children

A double-blind and randomized study design was used to investigate 100 healthy children, aged 1-5 years. Intubating conditions and cardiovascular changes during deep halothane anaesthesia, defined as an end-tidal concentration of 2%, were compared with those changes during 1% halothane and suxamethonium relaxation. Intubating conditions were graded according to the ease of laryngoscopy, vocal cord position, coughing and jaw relaxation. In each group 96% of the children demonstrated acceptable intubating conditions. Jaw relaxation was worse in the 1% halothane/-suxamethonium group (P < 0.01). When anaesthesia with 2% or 1% halothane was compared there was a more pronounced decrease in systolic blood pressure (18 vs. 8%, P < 0.001). Junctional rhythm occurred more frequently during deep halothane anaesthesia (46 vs. 18%, P < 0.01). Intravenously (i.v.) administered atropine attenuated blood pressure depression significantly and reinstituted sinus rhythm in most cases.

[Human spongiform encephalopathies. Diseases caused by prions]

Spongiform encephalopathies or prion diseases are common denominators for a group of diseases, all fatal, which show characteristic neuropathological changes. In man the group includes four diseases: kuru, Creutzfeldt-Jakob's disease (CJD), Gerstmann-Sträussler-Scheinker's disease (GSS) and fatal familial insomnia (FFI). In animals it comprises the following six: scrapie (sheep and goats), transmissible mink encephalopathy (mink), chronic wasting disease (mule/elk), exotic ungulate encephalopathy (antelopes) and feline and bovine spongiform encephalopathy (cats and cattle). The diseases can be transmitted to other animal species, including mice, hamsters, rats, monkeys and chimpanzees. The diseases show common histopathological changes in both animals and man, which are restricted to the CNS, in none of them are there signs of an inflammatory process or fever, and the cellcount in the CSF is normal. Disease symptoms are characterized by loss of higher levels of brain functions resulting in dementia and ataxia as the most pronounced symptoms. All prion diseases are associated with accumulation of an abnormal, partially proteinase-resistant isoform of a host-coded protein, the prion-protein (PrP), which is a cell surface sialoglycoprotein of unknown significance. PrP is highly conserved among mammals and is expressed in most tissues. Diseases caused by prions are exceptional as they can occur sporadically and are transmissible both genetically and infectiously. This review attempts to elucidate the present knowledge of the natural history of these diseases in man.

[Drug induced fatal anaphylactic shock in Denmark 1968-1990]

Based on notifications to the Danish Committee on Adverse Drug Reactions and to the Central Death Register, 30 cases of fatal drug-induced anaphylactic shock were identified during the period 1968-1990. The most frequent causes were contrast media for X-ray examinations, antibiotics, and extracts of allergens. Nine cases occurred outside hospital; they were mainly caused by the use of allergen extracts of moulds for desensitization in general practice. Fatal drug-induced anaphylactic shock is rare, estimated in the present study at 0.3 cases per million inhabitants per year.

[Nutritional and fluid supplementation for neonates. Types and use of supplementation in maternity wards]

The objective of the study was to evaluate the practice of giving supplementary feeding to newborns on maternity wards according to type of supplement, use and choice of supplement in different clinical settings, recommended frequency of breast-feeding, recommended types of infant formula and finally the influence of paediatric department and geographic site on the use of different types and use of supplements at the wards. Sixty maternity wards (95%) in Denmark filled in and returned the questionnaire. The maternity wards offered six different kinds of supplements and 36% of the maternity wards offered human milk. The study gave the impression of a large consumption of supplements on the maternity wards. Most of the maternity wards (83%) would recommend hydrolysed infant formula for infants with a family history of allergy, and almost the same number (88%) would recommend traditional infant formula for infants without a family history of allergy. Mothers' request for hydrolysed infant formula for infants without a family history of allergy was refused in 20% of the maternity wards. There were no differences between the recommended frequencies of breast-feeding. Maternity wards in hospitals with paediatric departments would significantly more frequently offer the infants supplements than maternity wards in hospitals without paediatric departments. The same maternity wards would significantly more often use water and human milk and more rarely water with glucose than maternity wards in hospitals without paediatric departments. In the western part of Denmark the maternity wards significantly more often used traditional infant formula and water with glucose than in the eastern part of Denmark. In conclusion, the investigation showed a considerable variation in the different types of supplements used in the maternity wards. The variation was influenced by the presence of a paediatric department in the hospital as well as by the geographic site. To ensure a higher and more uniform quality in this area it would be desirable if The National Board of Health in collaboration with the Allergy committee in the Danish Society of Paediatricians would publish recommendations to all who work professionally with mothers and infants.

[The significance of psychosocial stress for pregnancy course and fetal development]

In a population-based study, 3021 women in a central Copenhagen district received a questionnaire on environmental and psychological factors during mid-gestation. Of these, 70 women were selected consecutively on the basis of moderate to severe stressful life-events (DSM-III-R categories 3 to 5), in combination with an inadequate social network. They were compared with 50 non-stressed women with an intact social network. Stress and smoking significantly affected birthweight and head circumference. When birthweight was corrected, stress remained a significant determinant of small head circumference, indicating a specific effect on brain development. Stress also led to a suboptimal Prechtl neonatal neurological score. These findings suggest the existence of a fetal stress syndrome with adverse effects on fetal development, including deficient brain development.

Intrauterine growth retardation and premature delivery: the influence of maternal smoking and psychosocial factors

OBJECTIVES

This study investigated the influence of psychosocial stress, maternal schooling, social support, psychological well-being, alcohol, and smoking on intrauterine growth retardation and premature delivery.

METHODS

At a Copenhagen university hospital, 2432 pregnant women completed a questionnaire on general health, psychosocial stressors, and sociodemographic characteristics.

RESULTS

In 212 cases (8.7%) the women delivered prematurely. Preterm delivery as associated with psychosocial stress (adjusted odds ratio [OR]=1.14 for each 1-point increase on the psychosocial stressor 5-point scale and 1.92 for the whole scale) and poor school education (adjusted OR=2.62 for 7-9 years of schooling, 1.91 for 10 years, and 1.0 for 11-13 years). In 152 cases (6.3%), infants had a birthweight below the 10th percentile. Intrauterine growth retardation was associated with smoking, daily drinking, school education, and social network variables. In a multiple logistic regression model, intrauterine growth retardation was associated with smoking habits (adjusted OR=2.40 for 0-9 cigarettes daily, 2.68 for 10-15 daily, and 2.88 for more than 15 daily).

CONCLUSIONS

Psychosocial stressors and limited duration of schooling appeared to influence preterm delivery. Smoking habits influenced intrauterine growth retardation.