Induction of interferon in mice by sodium salt of 9-oxo-10-acridineacetic acid: specific enhancement by analogs

9-oxo-10-acridineacetic acid bearing the common name of 10-carboxymethyl-9-acridanone or CMA (6) was found to be a very potent interferon (IFN) inducer in adult Balb/c mice. Seven structural analogs of CMA were synthetized and assayed for the interferon inducing ability. Three of the compounds had new chemical structures. The analogs were shown to be either weak or inactive interferon inducers. However, some of the analogs administered intraperitoneally (i.p.) or orally (p.o.) either 2 h before CMA or together with the active inducer enhanced by 10 to 60-fold the serum interferon response. We suggest that CMA induces interferon indirectly via a specific protein receptor. The specific enhancement of the serum interferon response to CMA by its inactive analogs may be explained in terms of the competition of the compounds for binding sites at the acceptor or transporting protein molecules. In the presence of an analog of CMA greater amount of free CMA may be available for the receptors in the target cells than when CMA acts alone. Only CMA bound to the receptor would be biologically active whereas the complexes of the compounds with the acceptor are biologically inert.     

Incidence of venous air embolism during cesarean section is unchanged by the use of a 5 to 10 degree head-up tilt

One hundred healthy parturients were divided at random into two demographically similar groups and were positioned for cesarean section either horizontally or flexed 5 to 10 degrees head up, with a 15 degrees lateral tilt. A Doppler ultrasound transducer was positioned over the fourth intercostal space parasternally. Initially, two patients received spinal, three general, and 95 epidural anesthesia. Two patients subsequently needed general for failed epidural anesthesia. Changes in Doppler heart tones (greater than 15 sec duration) indicative of venous air embolism (VAE) were identified 15 times in 11 patients--seven in supine and four in head-up patients (no statistically significant difference). Six awake patients (three horizontal, three head-up) developed chest tightness or pain during surgery, but only one episode correlated with VAE. No patient developed breathlessness. Moderate hypotension (greater than 10% decrease in systolic arterial pressure [SAP]) occurred in seven of 11 (63.6%) patients with, and in 26 (29.2%) of 89 patients without, VAE (P less than 0.001). More severe hypotension (SAP less than 90 mm Hg) due to bleeding occurred once. We conclude that a modest (5-10 degrees) head-up position does not influence the occurrence of VAE in patients having cesarean section. An 11% incidence of clinically insignificant VAE, although low, is still worrisome, as even small air bubbles in the circulation are potentially harmful, especially if the foramen ovale is patent. VAE during cesarean section should be anticipated and the anesthetic management planned accordingly.     

Influence of fever on cefotaxime pharmacokinetics

The role of fever on cefotaxime disposition was studied in ten hyperthermic patients. Each subject received intravenously 1 g of cefotaxime on two separated occasions, first when the body temperature was more than 39 degrees C then during a basal state (37 degrees C). Blood samples were taken over 12 hours and urine was collected for 24 hours after injection. After dosing cefotaxime and its metabolite by high performance liquid chromatography, the pharmacokinetic parameters were calculated, especially: plasma and renal clearance, volume of distribution at steady state, area under the curve, and elimination half-life. There is no significant difference in cefotaxime and desacetylcefotaxime disposition between these two states. Hyperthermia has no influence on pharmacokinetics of this cephalosporin.     

Brain and lungs at risk after cervical spinal cord transection: intracranial pressure, brain water, blood-brain barrier permeability, cerebral blood flow, and extravascular lung water changes

The early physiopathologic responses to transection of the cervical spinal cord (C-4) were studied in the experimental animal. After transection, increases were seen in the mean arterial pressure, pulmonary capillary wedge pressure, intracranial pressure, brain water, blood--brain barrier permeability, and extravascular lung water with a marked decrease occurring in cerebral blood flow. Pretreatment with an alpha-adrenergic blocker, phentolamine (Regitine Ciba-Geigy Corp.), followed by transection blocked the rise in mean arterial blood pressure and pulmonary capillary wedge pressure but did not affect the increases in intracranial pressure, brain water, blood--brain barrier permeability, and extravascular lung water and decreases in cerebral blood flow. Transection of the cervical spinal cord initiates a complex series of events involving intracranial compliance and pulmonary permeability, placing both brain and lungs at risk.     

Mechanical and neurological response of cat spinal cord under static loading

The force/deformation relationship of the exposed spinal cord of cats was studied when the force was gradually applied posteriorly at T10. A linear elastic behavior was identified for deformation less than 0.5 mm, but it was not observed when the static force was no longer supported by the dural sheath. Nonlinear force/deformation relationships were observed for larger deformation, along with a strong hysteresis during a cycle of compression and decompression. The mechanical behavior remained practically the same in a repeated loading if the deformation was less than 2 mm. The motor function of cats did not recover after the cord had been compressed to 4 mm. The associated static force was about 15% of the dynamic force producing the same deformation.     

Road traffic noise in southern Sweden and its relation to annoyance, disturbance of daily activities and health

OBJECTIVES: This study investigated residential noise from road traffic and its relation to annoyance, disturbance of daily activities, and general health. METHODS: A large public health survey in southern Sweden in 1999-2000 supplied data (N=13 557; 54% participation rate) on the demography, annoyance, and disturbance of daily activities, and on general health problems regarding concentration, sleep, stress, and treatment for hypertension. Residential road noise exposure was assessed with a geographic information system. Associations with 24-hour equivalent (average) and maximum road noise level were investigated for all participants and for selected subgroups using the Cochran-Armitage trend test and Cox regression analysis. RESULTS: Annoyance from road traffic noise and the disturbance of daily activities increased markedly with road noise exposure. More than 25% reported at least occasional disturbance from traffic noise during relaxation and sleep in the highest exposure category for each noise measure. No overall pattern between road noise exposure and general health problems emerged. Among the participants that reported annoyance from road traffic noise (N=623), the average road noise level was associated with concentration problems (P for trend = 0.03) and with treatment for hypertension (P for trend = 0.02). Positive associations between average road noise exposure and health problems were found among females (hypertension), persons born outside Sweden (sleep), the unemployed (stress), and participants that reported financial problems (concentration problems). CONCLUSIONS: Exposure to road traffic noise at high levels was common and produced frequent disturbances of daily activities. Negative health effects from road traffic noise were observed in important subgroups. The findings are of concern for southern Sweden, as well as for other regions with similar or higher traffic intensity.     

Fertility among female hairdressers

OBJECTIVES: The study investigated whether working as a hairdresser has a negative impact on fertility, measured as time to pregnancy and miscarriage risk. METHODS: Self-administered questionnaires were sent to 5289 Swedish hairdressers (response rate 50%) and to 5299 age-matched women from the general Swedish population (response rate 54%). Information was collected on time to pregnancy or trying time for women who had tried, but failed, to conceive at the time of the study. The outcome of the pregnancy was determined and categorized as either miscarriage or stillbirth or live birth. The hairdressers were compared with the referents with respect to these two outcomes. Within the hairdresser cohort, the effects of hair treatments, as well as physical workload and stress were investigated. RESULTS: The hairdressers were less successful than the reference cohort in conceiving (fecundability ratio 0.91, 95% confidence interval 0.83-0.99). The effect was reduced after first-month conceptions were excluded, the indication being that the effect may be the result of birth control bias. Within the hairdresser cohort, a self-perceived stressful work situation seemed to prolong the time to pregnancy. No effects were found for the different chemical hair treatments. There was no cohort difference with respect to miscarriage risk (odds ratio 1.12, 95% confidence interval 0.88-1.42), but miscarriage risks were increased for most of the hair treatments and for self-perceived stressful work situations. However, none of these effects were statistically significant. CONCLUSIONS: The present study indicates a negative impact on time to pregnancy and miscarriage risk for working as a hairdresser".