Nerve cell damages in whiplash injuries. Animal experimental studies

Mechanical loading of the cervical spine during car accidents often lead to a number of neck injury symptoms with the common term Whiplash Associated Disorders (WAD). Several of these symptoms could possibly be explained by injuries to the cervical spinal nerve root region. It was hypothesised that the changes in the inner volume of the cervical spinal canal during neck extension-flexion motion would cause transient pressure changes in the CNS as a result of hydro-dynamic effects, and thereby mechanically load the nerve roots and cause tissue damage. To test the hypothesis, anaesthetised pigs were exposed to experimental neck trauma in the extension, flexion and lateral flexion modes. The severity of the trauma was kept below the level where cervical fractures occur. Transient pressure pulses in the cervical spinal canal were duly recorded. Signs of cell membrane dysfunction were found in the nerve cell bodies of the cervical spinal ganglia. Ganglion injuries may explain some of the symptoms associated with soft-tissue neck injuries in car accidents. When the pig's head was pulled rearward relative to its torso to resemble a rear-end collision situation, it was found that ganglion injuries occurred very early on in the neck motion, at the stage where the motion changes from retraction to extension motion. Ganglion injuries did not occur when pigs were exposed to similar static loading of the neck. This indicates that these injuries are a result of dynamic phenomena and thereby further supports the pressure hypothesis. A Neck Injury Criterion (NIC) based on a theoretical model of the pressure effects was developed. It indicated that it was the differential horizontal acceleration and velocity between the head and the upper torso at the point of maximum neck retraction that determined the risk of ganglion injuries.     

Neurovirulence in feline immunodeficiency virus-infected neonatal cats is viral strain specific and dependent on systemic immune suppression

Feline immunodeficiency virus (FIV) is a lentivirus that causes immune suppression and neurological disease in cats. Among animal viruses, individual viral strains have been shown to be neurovirulent, but the role of viral strain specificity among lentiviruses and its relationship to systemic immune suppression in the development of neurological disease remains uncertain. To determine the extent to which different FIV strains caused neurological disease, FIV V1CSF and Petaluma were compared in ex vivo assays and in vivo. Both viruses infected and replicated in macrophage and mixed glial cell cultures at similar levels, but V1CSF induced significantly greater neuronal death than Petaluma in a neurotoxicity assay. V1CSF-infected animals showed significant neurodevelopmental delay compared to the Petaluma-infected and uninfected animals. Magnetic resonance spectroscopy studies of frontal cortex revealed significantly reduced N-acetyl aspartate/creatine ratios in the V1CSF group compared to the other groups. Cyclosporin A treatment of Petaluma-infected animals caused neurodevelopmental delay and reduced N-acetyl aspartate/creatine ratios in the brain. Reduced CD4(+) and CD8(+) cell counts were observed in the V1CSF-infected group compared to the uninfected and Petaluma-infected groups. These findings suggest that neurodevelopmental delay and neuronal injury is FIV strain specific but that systemic immune suppression is also an important determinant of FIV-induced neurovirulence.     

Thoracic actinomycosis: CT findings

PURPOSE: To characterize computed tomographic (CT) findings of thoracic actinomycosis. MATERIALS AND METHODS: Chest CT scans and radiographs obtained in 22 patients with histopathologically proved thoracic actinomycosis were retrospectively reviewed. All patients were immunocompetent; they were aged 12-73 years (mean, 42.6 years; 14 male, eight female). CT findings were correlated with histopathologic findings in nine patients who underwent surgery (lobectomy [n = 8] or segmental resection [n = 1]). RESULTS: All of the lesions were unilateral, with an average diameter of 6.5 cm (range, 2-12 cm). Patchy air-space consolidation (n = 20) or a mass (n = 2) was seen on CT scans. Fifteen (75%) of the 20 patients with air-space consolidation had central areas of low attenuation (5-30 mm in diameter) within the consolidation. Thirteen of the 15 patients underwent contrast medium-enhanced CT. Ten (77%) of the 13 patients showed ring-like rim enhancement. Adjacent pleural thickening was seen in 16 patients (73%). At histopathologic examination, central low-attenuation areas at CT were seen as microabscesses with sulfur granules or a dilated bronchus that contained inflammatory cells and Actinomyces colonies. Peripheral enhancement of the low-attenuation areas was wall of the microabscess or surrounding parenchyma composed of granulation tissue rich in vascularity. CONCLUSION: Findings of chronic segmental air-space consolidation that contained low-attenuation areas with peripheral enhancement or adjacent pleural thickening at CT were suggestive of thoracic actinomycosis.     

Cloning and characterization of plastid ribosomal protein S16 gene from potato (Solanum tuberosum L. cv Désirée)

STUDY OBJECTIVE: To determine whether an intensive educational campaign of emergency department personnel on the organ donor and procurement process would result in both increased organ donor referrals and organs procured. METHODS: A retrospective review of the performance of an urban teaching ED in identifying and referring potential organ donor candidates was performed. Subsequently an intensive educational campaign of all ED staff, in conjunction with the Regional Organ Procurement Agency of Southern California (ROPA), was initiated. Physicians and nurses were educated about the procurement process, and a ROPA representative was on call 24 hours a day to assist in this process. The need for aggressive resuscitation and vital sign maintenance in potential donors as a strategy to promote organ recovery was emphasized. Reeducation by ROPA occurred every 2 to 3 months. The identification and referral rates were then retrospectively reviewed to evaluate any improvement. RESULTS: In 1994 the initial referral rate of potential organ donors from the ED was 30% (3 of 10) resulting in no organs procured. After the intervention the referral rate increased to 100% (25 of 25) in 1995 (P < .0001). The number of actual donors procured was 0 in 1994, 5 in 1995, and 9 in 1996. The increased ED referrals resulted in 14 and 32 organs procured in 1995 and 1996, respectively. CONCLUSION: Emergency physicians are in a unique position as first caregivers to interact with both potential donors and their families. With intensive education of ED staff, proper identification and referral, as well as timely intervention by organ procurement representatives, the consent and donation rate of organs for transplantation can be increased and maintained.     

Clinical response of localized recurrent periodontitis treated with scaling, root planing, and tetracycline fiber

The purpose of this study was to compare the clinical efficacy of scaling and root planing alone versus tetracycline fiber therapy used adjunctively with scaling and root planing in the treatment of nonresponsive active periodontitis in patients under supportive periodontal therapy. Thirty patients who were receiving supportive treatment and had at least two nonadjacent periodontitis sites with a probing depth of between 4 and 8 mm and bleeding on probing, or had aspartate aminotransferase (AST) levels above 800 microIU in the gingival crevicular fluid in separate quadrants participated in this study. For each patient, the test sites were treated with scaling and root planing plus tetracycline fibers while the control site was treated with scaling and root planing only. Probing depths, clinical attachment levels, gingival recession, AST levels, and bleeding on probing were recorded and subgingival plaque samples were collected at baseline and 1, 3, and 6 months following treatment. At 3 months after treatment, there was a reduction of bleeding on probing and probing depth, and a gain of clinical attachment in both test and control sites. The mean reduction in probing depth of the test sites was 1.38 mm and the attachment gain was 0.8 mm after 6 months. The clinical response obtained at 3 months following therapy was maintained throughout the 6-month follow-up period. However, there were no statistically significant differences between sites treated with scaling and root planing alone and those treated with combined tetracycline therapy. Most of the reductions of probing depths in the fiber group were attributed to gingival recession. The present study did not confirm the efficacy of adjunctive tetracycline fibers in treating nonresponsive sites in maintenance subjects with regard to probing depth reduction or clinical attachment gain. Reinfection of the pockets from untreated sites and extra-crevicular regions may explain the insignificant response to local tetracycline therapy.     

Growth hormone axis in cushing''s syndrome

This article reviews some recent studies on alcohol preference, dependence, metabolism and pharmacokinetics which were mainly carried out in our department. The inbred strains of mice with genetically different alcohol drinking behavior and alcohol animal model treated with the neurotoxins, 6-hydroxydopamine and 5,7-dihydroxytryptamine, are useful for a behavioral and pharmacological approach to evaluate the contribution of specific neural systems to alcohol, drug dependence mechanism and alcohol drinking behavior. The relations between alcohol preference and some physiological conditions are reviewed. On the drug-alcohol interaction, some drugs containing the chemical group = CHONO2, antimony and methamphetamine are addressed. This article also deals with recent topics in the pharmacokinetics and pharmacodynamics of alcohol. The dose-dependency of the alcohol elimination rate, the first-pass metabolism during alcohol drinking, and the pharmacodynamic model for describing pulse rate reaction to plasma acetaldehyde are discussed.     

Circulating maternal serum progesterone in high-risk pregnancies

Serum progesterone was measured by competitive protein-binding assay in 331 cases of normal pregnancy ranging from 6 to 42 weeks. Serial estimations of serum progesterone were performed in nine cases of severe hypertensive disorder of pregnancy, eight cases of twin pregnancy, three cases of twin pregnancy complicated by severe hypertensive disorder of pregnancy, three cases of triplet pregnancy, three cases of previous bad obstetric history, one case of anencephaly, and seven cases of intrauterine fetal death. Serum progesterone remained within normal range in severe hypertensive disorder of pregnancy and the levels were indistinguishable in cases of fetal growth retardation from those without growth retardation. In twin and triplet pregnancies, serum progesterone was within normal range or elevated and was usually higher than normal in twin pregnancies after weeks 33 to 34. Serum progesterone levels were normal in anencephalic pregnancy and in most cases of intrauterine fetal death. The findings are discussed with reference to placental hormonal activity. It is concluded that serum progesterone is a poor index of placental function.     

The use of serum carbohydrate-deficient transferrin in the assessment of 'high risk offenders' in Great Britain

The potential role of serum carbohydrate-deficient transferrin (CDT) measurement in the assessment of 'High Risk Offenders (HROs)' applications for licence reinstatement in Great Britain was examined. Serum CDT determination would have provided useful confirmation of licence decisions in 70% of HROs assessed, would have resulted in a change in the licence decision in 8%, and most likely would have confounded the licence decisions made in the remaining 22%. Estimation of serum CDT could provide useful information to assist in decisions regarding licence reinstatement in selected HROs.