Neocortical ectopias in BXSB mice: effects upon reference and working memory systems

BXSB mice have an approximately 40-60% incidence of neocortical ectopias in layer I of the prefrontal/motor cortex. Prior studies have found major behavioral differences between those with ectopias and their non-ectopic littermates. Some of these findings indicate that the two groups differ with respect to spatial reference and working memory. The purpose of this study was to measure reference and working memory in the same animals to test the hypothesis that the ectopics would have better reference memory but less effective working memory. The Lashley III maze has cul-de-sacs which must be eliminated, and T-choices where the animal has to decide whether to go left or right. Ectopic and non-ectopic mice were equally able to learn the maze and did not differ on cul-entry or T-choice errors. Then the maze was inverted and the animals were retested. Turning the maze upside down did not change the relative status of the blind alleys. Therefore, the reference memory knowledge from the prior week's training could be used to avoid entering the culs. However, inverting the maze caused a left-right mirror image reversal of the T-choices. Therefore, prior reference memory information would interfere with learning the new path through the maze, whereas working memory would enable the mouse to eliminate T-choice errors. Ectopic mice made less cul-entry errors and more T-choice errors than their non-ectopic littermates, as predicted.     

Public participation in radiological surveillance

In 1989, Pacific Northwest National Laboratory developed a program, for the U.S. Department of Energy, to involve local citizens in environmental surveillance at the Hanford Site. The Community-Operated Environmental Surveillance Program was patterned after similar community-involvement efforts at the Nevada Test Site and the Three Mile Island nuclear facility. Its purpose is to increase the flow of information to the public, thereby enhancing the public's awareness and understanding of surveillance activities. The program consists of two components: radiological air monitoring at nine offsite locations and agricultural product sampling at selected locations near the site. At each air-monitoring station, two local school teachers collect air particulate samples and operate equipment to monitor ambient radiation levels. Atmospheric tritium samples (as water vapor) are also collected at some locations. Four of the air-monitoring stations include large, colorful informational displays for public viewing. These displays provide details on station equipment, sample types, and sampling purposes. Instruments in the displays also monitor, record, and show real-time ambient radiation readings (measured with a pressurized ionization chamber) and meteorological conditions. Agricultural products, grown primarily by middle-school-aged students, are obtained from areas downwind of the site. Following analysis of these samples, environmental surveillance staff visit the schools to discuss the results with the students and their teachers. The data collected by these air and agricultural sampling efforts are summarized with other routinely collected sitewide surveillance data and reported annually in the Hanford Site environmental report.     

Genitourinary trauma in the pediatric patient

Trauma is the major source of mortality in the pediatric population. A retrospective review was performed on patients admitted to the Children's Hospital and Health Center Trauma Program, San Diego, California, from August 1984 to May 1990. The purpose of this review was to evaluate pediatric trauma and to determine the best treatment and evaluation for genitourinary injuries. Blunt trauma was responsible for 98 percent of the injuries, with renal injuries being the most common. Bladder (7) and male urethral (2) injuries, and vaginal lacerations (8) also occurred. The most severe renal injuries (70%) and all significant bladder and urethral injuries were associated with gross hematuria. Hypotension was present in 31 percent of patients but rarely required surgical exploration for correction. Eighty-six patients underwent radiographic imaging. Computerized tomography (CT) scans demonstrated the most information about intra-abdominal solid organ injuries but was inaccurate in detecting bladder or urethral injuries. Genitourinary injury is common in children but rarely requires surgical management. CT scan is the best study to determine extent of solid-organ injury but is inferior to cystourethrography to diagnose bladder or urethral injuries.     

Gene expression in brain during cuprizone-induced demyelination and remyelination

When C57BL/6J mice, 8 weeks of age, received 0.2% Cuprizone in their diet, extensive demyelination in corpus callosum was detectable after 3 weeks, and there was massive demyelination by 4 weeks. As expected, the accumulation of phagocytically active microglia/macrophages correlated closely with demyelination. When Cuprizone was removed from the diet, remyelination was soon initiated; after 6 weeks of recovery, myelin levels were near-normal and phagocytic cells were no longer prominent. Steady-state levels of mRNA for myelin-associated glycoprotein, myelin basic protein, and ceramide galactosyltransferase were already profoundly depressed after 1 week of Cuprizone exposure and were only 10-20% of control values after 2 weeks. Unexpectedly, upregulation of mRNA for these myelin genes did not correlate with initiation of remyelination but rather with accumulation of microglia/macrophages. After 6 weeks of exposure to Cuprizone, mRNA levels were at control levels or higher-in the face of massive demyelination. This suggests that in addition to effecting myelin removal, microglia/macrophages may simultaneously push surviving oligodendroglia or their progenitors toward myelination.     

Clinical significance of sleep apnea disorders after implantation of a cardioverter-defibrillator in patients with cardiac disease and sustained ventricular tachyarrhythmia

The purpose of our study was to determine the prevalence of sleep related breathing disorders (SRBD) in patients with an implantable cardioverter-defibrillator (ICD) and to evaluate prospectively the possible influence of SRBD on arrhythmia recurrence and circadian arrhythmia variation as well as on cardiac mortality during long-term follow-up. Forty consecutive ICD recipients with cardiac disease and a documented history of spontaneous, life-threatening, ventricular tachyarrhythmias underwent full-night polysomnography and were followed for 2 years. In 16 of 40 patients (40%), SRBD were diagnosed (Apnea/Hypopnea Index (AHI) > 10); in 9 of these 16 patients (56%) central sleep apneas (CSA) occurred (in 8 of these 9 patients in combination with Cheyne-Stokes respiration). Seven of the 16 patients with SRBD (44%) revealed obstructive sleep apneas (OSA). AHI was 32 +/- 15 (12-60) in patients with CSA and 32 +/- 27 (11-86) in patients with OSA. Patients with and without SRBD were comparable concerning left ventricular ejection fraction, NYHA classification, cardiac disease, ICD indication, and concomitant medication. ICD registered ventricular tachyarrhythmias occurred in 10 of 24 patients (42%) without SRBD, in 4 of 9 patients (44%) with CSA, and in 3 of 7 patients (44%) with OSA. The numbers and circadian variation of episodes registered during follow-up in patients without SRBD, with OSA or CSA were comparable (14 +/- 25, median 4 vs 15 +/- 15, median 7 vs 4 +/- 5, median 2.5). The 2-year cardiac mortality was highest in patients with CSA (4/9 (44%) vs. 0/7 patients (0%) with OSA vs 3/24 patients (12.5%) without SRBD. Thus, the prevalence of SRBD in patients with chronic heart failure and a history of malignant ventricular tachyarrhythmias is high (40%) and the occurrence of CSA seems to be predictive for cardiac mortality in these patients. An influence of moderate SRBD on arrhythmia recurrence and circadian variation of spontaneous sustained tachyarrhythmic events could not be demonstrated.     

Culture and characterization of sinusoidal endothelial cells isolated from human liver

BACKGROUND: Epidemiologic data concerning skin diseases in many rural areas in sub-Saharan Africa are not available. Little is known about the effect of regular treatment schedules by paramedical staff (especially community health workers) in the primary healthcare system on the severity and prevalence of dermatoses. METHODS: 5780 school and pre-school children from 13 primary schools in four sublocations in rural western Kenya (Kisumu District) were examined for dermatoses by the author, together with community health workers in 1993. On-the-spot training and weekend seminars about important and common dermatoses were also given. In 1994 a dermatology program was started within the primary healthcare system. Twelve trained community health workers carried out regular school visits once a week and diagnosed and treated pupils with dermatoses. Treatment was performed with gentian violet 1% solution for bacterial skin infections, Whitfield's ointment for dermatophytoses, benzylbenzoate emulsion 25% for scabies, and hydrocortisone acetate 1% cream for eczemas. All schools were visited again in 1995 to evaluate the long-term effects of the program. RESULTS: In 1993, the prevalence rate for dermatoses was 32.4%. Most of the skin diseases found were of infective origin (27.1% were caused by bacteria, 21.6% by fungi, and 17.6% by arthropods, mainly scabies mites). Dermatitis accounted for 3.5%. In 1995, the prevalence of dermatoses declined to 29.6% (p<0.05), and this reduction was most strongly observed for tropical ulcers and tinea capitis. Additionally, there was an improvement in the extent and severity of skin diseases. CONCLUSIONS: This study defines, for the first time, the number and extent of skin diseases in children in rural Kisumu District; most dermatoses were of infective origin. The study demonstrates that community health workers in the primary healthcare system are capable of dealing successfully with the most common dermatoses in children following a short training period.     

Altered hippocampal kainate-receptor mRNA levels in temporal lobe epilepsy patients

This study determined whether hippocampal kainate (KA) receptor mRNA levels were increased or decreased in temporal lobe epilepsy patients compared with nonseizure autopsies. Hippocampal sclerosis (HS; n = 17), nonsclerosis (non-HS; n = 11), and autopsy hippocampi (n = 9) were studied for KA1-2 and GluR5-7 mRNA levels using semiquantitative in situ hybridization techniques, along with neuron densities. Compared with autopsy hippocampi, HS and non-HS cases showed decreased GluR5 and GluR6 hybridization densities per CA2 and/or CA3 pyramid. Furthermore, HS patients demonstrated increased KA2 and GluR5 hybridization densities per granule cell compared with autopsy hippocampi. These findings indicate that chronic temporal lobe seizures were associated with differential changes in hippocampal KA1-2 and GluR5-7 hybridization densities that vary by subfield and pathology group. In temporal lobe epilepsy patients, these results support the hypothesis that pyramidal cell GluR5 and GluR6 mRNA levels are decreased as a consequence of seizures, and in HS patients granule cell KA2 and GluR5 mRNA levels are increased in association with aberrant fascia dentata mossy fiber sprouting and/or hippocampal neuronal loss.     

Efficacy of arthroscopic lysis and lavage in patients with temporomandibular joint symptoms associated with generalized osteoarthritis or rheumatoid arthritis

PURPOSE: This study evaluated the efficacy of arthroscopic lysis and lavage in patients with temporomandibular joint (TMJ) symptoms and generalized osteoarthritis (GOA) or rheumatoid arthritis (RA). PATIENTS AND METHODS: Twenty-three GOA patients and 23 RA patients were evaluated after 1 year. RESULTS: Seventeen of 23 patients (74%) in the RA group improved after arthroscopic lysis and lavages compared with 10 of 23 (43%) of the GOA patients. Lateral joint tenderness, crepitation, maximal opening, and maximal protrusion showed most improvement in the RA group. CONCLUSIONS: On the basis of this short-term follow-up study, arthroscopic lysis and lavage seem to provide an effective treatment for TMJ pain and dysfunction in RA patients but not in GOA patients.     

DSM-IV field trials for oppositional defiant disorder and conduct disorder in children and adolescents

OBJECTIVE: The purpose of the field trials for oppositional defiant disorder and conduct disorder was to select valid diagnostic thresholds for these disorders and to compare the psychometric properties of DSM-IV criteria for oppositional defiant disorder and conduct disorder with previous DSM diagnostic formulations. METHOD: Structured diagnostic interviews, standardized clinician's validation diagnoses, and multiple measures of impairment were obtained for 440 clinic-referred children and adolescents aged 4-17 years. RESULTS: A diagnostic threshold of four symptoms of oppositional defiant disorder optimized identification of impaired children, improved agreement somewhat with the clinician's validation diagnosis, and had somewhat better test-retest agreement than DSM-III-R. In the case of conduct disorder, the optimal time window for ascertainment of symptoms was clarified. A diagnostic threshold of three symptoms of conduct disorder maximized accurate identification of impaired children and agreement with the clinician's validation diagnosis and resulted in slightly better test-retest agreement than DSM-III-R. Compared with the DSM-III-R definition, the DSM-IV definition of oppositional defiant disorder was somewhat more prevalent, but the prevalence of conduct disorder was essentially unchanged. CONCLUSIONS: DSM-IV definitions of oppositional defiant disorder and conduct disorder are somewhat better than DSM-III-R definitions in terms of internal consistency and test-retest agreement, and the validity of the DSM-IV definition of oppositional defiant disorder is slightly better than that of DSM-III-R.