Alterations in temporal/spatial distribution of GFAP- and vimentin-positive astrocytes after spinal cord contusion with the New York University spinal cord injury device

Astrocytes become reactive as a result of various types of lesions and upregulate 2 intermediate filaments, glial fibrillary acidic protein (GFAP), and the developmentally regulated protein vimentin. Young female Sprague-Dawley rats were subjected to a spinal cord contusion at segment T10 using the New York University injury device. Animals were killed at 1, 2, 7, 14, and 30 days postinjury. Horizontal spinal cord sections spanning segments T7-T13 were assessed with antibodies to both intermediate filament proteins. The number of gray matter GFAP-positive astrocytes increased by 2 days postinjury, with segments adjacent (proximal) to the injury site showing greater responses than areas several segments away (distal). By 30 days following injury, astroglial cell numbers returned to normal levels. Vimentin-positive astrocytes also showed a graded proximal/distal response by 2 days following injury. Proximal regions remained significantly higher at 30 days following injury than control animals. Rostral/caudal changes were also evident, with regions caudal to the injury showing significantly higher numbers of vimentin positive astrocytes than those rostral, indicating that gray matter areas caudal to spinal cord injury may undergo more stress following spinal cord injury.     

The entry of [D-penicillamine2,5]enkephalin into the central nervous system: saturation kinetics and specificity

The delta opioid receptor-selective, enzymatically stable peptide [D-Penicillamine2,5]enkephalin (DPDPE) has recently acquired special significance with the identification of a saturable uptake system for this analgesic into the CNS. The aim of the present study was to characterize further the entry of [3H]DPDPE into the brain and CSF by means of a bilateral in situ brain perfusion method. Initial experiments revealed a saturable [3H]DPDPE uptake into the brain that followed Michaelis-Menten type kinetics with a K(m) value of 45.5 +/- 27.6 microM, a V(max) value of 51.1 +/- 13.2 pmol x min(-1) x g(-1) and a K(d) value of 0.6 +/- 0.3 microl x min(-1) x g(-1). Uptake of [3H]DPDPE into the CSF could not be inhibited (K(d) = 0.9 +/- 0.1 microl x min(-1) x g(-1)). Entry of [3H]DPDPE into the CNS was not inhibited in the presence of 10 mM 2-aminobicyclo-[2,2,1]-heptane-2-carboxylic acid (BCH) or 50 microM ICI 174,864, which suggests that the saturable mechanism does not involve the large neutral amino acid transporter or binding to opioid receptors. It would also appear that [3H]DPDPE is not in competition with either poly-L-lysine or insulin to enter the CNS. However, both of these substances significantly increased the CNS entry of [3H]DPDPE but not that of the vascular space marker [14C]sucrose, and this may have valuable clinical implications. It is not known at present which saturable uptake mechanism is responsible for the CNS entry of [3H]DPDPE, but overall the results suggest a carrier-mediated transport system.     

Analysis of tube thoracostomy performed by pulmonologists at a teaching hospital

STUDY OBJECTIVE: To evaluate all tube thoracostomies (TTs) done by pulmonary/critical care fellows and attending physicians in the Medical University of South Carolina's health-care system documenting patient demographics, indication for placement, size and characteristics of the tube, and associated problems. DESIGN: Prospective. SETTING: University health-care system, including a university hospital, a Veterans Affairs hospital, and a county hospital. PATIENTS: All adult patients requiring consultation by a member of the pulmonary/critical care staff for a tube thoracostomy. RESULTS: One hundred twenty-six tube thoracostomies were performed over a 24-month period in 91 patients. The most common initial indication for a TT was pneumothorax (69/103, 67%). Overall mortality in the patient population was 35% (32/91). Early problems (< 24 hours following placement) occurred in 3% (4/126); late problems (> 24 h after placement) occurred in 8% (10/126). Problems occurred in 36% (4/11) of small-bore tube placements vs 9% (10/115) of standard TT placements (p=0.02). CONCLUSIONS: Tube thoracostomy can be safely performed by pulmonologists with relatively few associated problems.     

New in vitro model of traumatic neuronal injury: evaluation of secondary injury and glutamate receptor-mediated neurotoxicity

The multiplicity and complexity of secondary injury processes following brain trauma in vivo make it difficult to elucidate the roles of specific injury mechanisms. As with other areas of CNS injury, such as ischemia, this has led to the development of in vitro models. Here we describe a new trauma model, in which standardized trauma is delivered to neuronal/glial cultures using a special mechanical device that produces concentric circular cuts in the cell layer. Changes in the number of circles (from 1 to 6) allows variation of injury severity. Comparison studies of cell death induced by such trauma in glial and neuronal/glial cultures demonstrated that glial cells are relatively resistant to this injury, and that the cell death after trauma to neuronal/glial cultures reflects primarily neuronal death. Consistent with other in vivo and in vitro studies, glutamate receptor antagonists MK 801 and MCPG were neuroprotective. Thus, this model appears useful for studying glutamatergic mechanisms involved in secondary injury, and may prove useful for evaluating certain pharmacological strategies for CNS trauma.     

Myocardial oxygen tension in isolated erythrocyte-perfused rat hearts and comparison with crystalloid media

The isolated heart, typically perfused with crystalloid media equilibrated with >/=95% O2 to ensure adequate myocardial oxygen tension, is commonly used to study cardiac function. When hemoglobin is available for oxygen transport, equilibration with 21% O2 is considered adequate to meet metabolic demands. This study presents the measurement of myocardial pO2 in isolated hearts perfused with an erythrocyte suspension. Baseline myocardial pO2 in erythrocyte-perfused hearts was 16.4+/-3.5 mmHg (mean+/-s.e.). When compared to previous measurements of myocardial pO2 in isolated hearts perfused with crystalloid media, the use of erythrocyte suspensions resulted in a 10-fold lower level of myocardial pO2, while avoiding very low and high values. The standard use of 95% oxygen with crystalloid results in myocardial levels of oxygen far above those usually found in the presence of hemoglobin and room air.     

Effects of self-care education on the health status of inner-city patients with osteoarthritis of the knee

OBJECTIVE: To evaluate a concise program of self-care education delivered by an arthritis nurse specialist as an adjunct to primary care for inner-city patients with knee osteoarthritis (OA). METHODS: An attention-controlled clinical trial; 211 inner-city patients with knee OA were assigned arbitrarily to education (E) or attention-control (AC) conditions. Group E received an individualized 30-60-minute educational intervention that emphasized nonpharmacologic management of joint pain, preservation of function by problem-solving, and practice of principles of joint protection. Brief telephone contacts 1 week and 4 weeks later monitored and reinforced new self-care activities. Group AC viewed a 20-minute standardized public education presentation on arthritis and received followup telephone calls (only to encourage continued participation in the study). Outcomes included the Health Assessment Questionnaire (HAQ) Disability and Discomfort Scales, 10-cm visual analog scales measuring knee pain at rest and while walking, and the Quality of Well-Being (QWB) scale. Assessments were made at baseline and at 4-month intervals for 1 year. RESULTS: A total of 165 subjects (78%) completed all assessments. After control for baseline status, group E had significantly lower scores for disability and resting knee pain throughout the year of postintervention followup (P < 0.05 for both). Effects were somewhat discordant. By 12 months, functional benefits had begun to wane, while the effect on resting knee pain had grown. The overall effects of education on walking knee pain, overall joint pain (by HAQ), and general health status (by QWB) were not significant. CONCLUSION: Self-care education for inner-city patients with knee OA, delivered as an adjunct to primary care, was found to result in notable preservation of function and control of resting knee pain. The magnitude of the observed effects compares well with those of more labor-intensive and time-consuming intervention models. However, more sustained preservation of function and consistent effects on pain may require prolonged, more proactive followup, either by the patient educator or by a trained clinical assistant dedicated to the task of supporting self-care by patients with knee OA.     

Basal cell tetrasomy in low-grade cervical squamous intraepithelial lesions infected with high-risk human papillomaviruses

We have analyzed 60 low-grade cervical squamous intraepithelial lesions for low- and high-risk human papillomaviruses (HPVs) and for numerical abnormalities of chromosomes 1, 3, 11, 17, and 18 and the X chromosome. Eleven of 33 lesions infected with high-risk HPVs (HPV 16, 18, 30, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 66) but none of 24 lesions infected with low-risk HPVs (HPV 6, 11, 42, 43, and 44) and none of 15 normal cervices showed basal cell tetrasomy of all six chromosomes in the HPV-infected areas. These changes were not HPV type specific and were not present in all lesions infected with the same HPV type. The presence of basal cell tetrasomy in lesions infected with high- but not low-risk HPVs suggests that induction of chromosome instability may be one mechanism underlying the biological differences between these viral types.     

Fine structure of the retinal pigment epithelium of Oreochromis niloticus L. (Cichlidae; Teleostei) in light- and-dark adaptation

To examine pathological changes of melanocytes in photodamaged skin, we performed a comparative cytomorphometric analysis and a qualitative observation of melanocytes from sun-exposed and sun-protected facial skin at the electron microscopic level. The characteristic ultrastructural features of melanocytes in photodamaged skin included a statistically significant increase in their number, a marked nuclear heterogeneity, signs of cell activation, close apposition to photodamaged degenerate keratinocytes, degenerative changes represented by large intracytoplasmic vacuoles, and frequent direct contacts with Langerhans cells. Cytomorphometric analysis revealed significant decreases in cell and nuclear sizes, increases in cell and nuclear perimeters accompanied by irregular contours, and higher degrees of nuclear ellipticity in sun-exposed melanocytes. This study demonstrates that there are remarkable differences in the morphology of melanocytes between photoaged and intrinsically aged facial skin, and supports the concept that photoageing processes contribute to cytological alterations in melanocytes.     

Anatomic variability of rejection in intestinal allografts after pediatric intestinal transplantation

The internal mammary artery is routinely used for coronary artery bypass grafting because of its optimal long-term patency profile. This vessel can be imaged by angiography, but only the proximal tract at the origin from the succlavian artery can be imaged by conventional echography. The aim of our study was to visualize the intrathoracic course of the native and grafted internal mammary arteries by a new ultrasound equipment which allows high-resolution transthoracic color Doppler imaging of the chest wall vessels and coronary arteries. We studied 35 patients, 16 non operated and 19 operated of coronary surgery with the internal mammary artery grafted to the left anterior descending coronary artery. We used a multifrequency 3.5-7 MHz transducer with a small insonating surface, placed at the second-fifth intercostal space at the left and right sternal border, to image the native mammary arteries. The grafted mammary artery was detected at the fourth-fifth left intercostal space 2-4 cm lateral to the sternal border. The native left internal mammary artery was visualized in all 16 non operated patients, and the right internal mammary artery in 14/16 (87%). The native left internal mammary artery peak flow velocity was 41-160 cm/s (mean 81 +/- 34 cm/s), and the mean flow velocity was 28-89 cm/s (mean 45 +/- 17 cm/s). The right internal mammary artery peak flow velocity was 35-153 cm/s (mean 82 +/- 36 cm/s), and mean flow velocity was 21-82 cm/s (mean 46 +/- 22 cm/s). The grafted left internal mammary artery was visualized in 16/19 patients (84%), evaluated at 6 days to 36 months after surgery. Peak diastolic flow velocity ranged from 24 to 80 cm/s (mean 48 +/- 17 cm/s), and mean diastolic flow velocity ranged from 13 to 57 cm/s (mean 33 +/- 11 cm/s). The left anterior descending peak flow velocity distal to the anastomosis was 22-62 cm/s (mean 37 +/- 15 cm/s) and mean flow velocity was 18-53 cm/s (mean 29 +/- 12 cm/s). We conclude that transthoracic color Doppler echocardiography allows to image the native and grafted mammary arteries, with potential clinical applications in the management of patients with coronary artery disease.     

Gastro-intestinal protein loss in late survivors of Fontan surgery and other congenital heart disease

A 2,048-bp nucleotide sequence containing a gene coding for an enzyme that degraded guar gum from Bacillus circulans K-1 was identified by polymerase chain reaction walking. This G-gene consisted of 1,551 nucleotides coding for a protein with Mr 55,242. The enzyme was overexpressed in Escherichia coli JM109 cells by the cloning the G-gene downstream of the lac Z promoter of pUC19. The molecular mass of recombinant G-enzyme estimated by SDS-PAGE was 62 KDa, close to that from strain K-1. Analysis of the recombinant enzyme showed GalNAc, Xyl, GlcNAc, Man, Glc, and Gal to account for 1.7%, 14.4%, 6.1%, 3.2%, 54.2%, and 10.4%, respectively, of the total monosaccharides. Polyacrylamide gel electrophoresis of this enzyme with staining gave a red band. The results suggested that the sugars accounted for the differences in the molecular masses. The recombinant enzyme had two kinds of N-terminal sequences, Thr-Met-Ile-Thr-Pro-Ser-Phe-Ala-Ser-Gly-Phe-Tyr-Val-Ile and Ile-Thr-Pro-Ser-Phe-Ala-Ser-Gly-Phe-Tyr-Val-Ile-Gly-Thr. Comparison of these sequences with the deduced N-terminal sequence coded for the G-gene showed that the amino acid, first Met, of the lac Z gene or the next residues Thr-Met in the recombinant enzyme were absent in the native enzyme. Methionines near and at the N-terminus of the mature protein probably were digested by methionine aminopeptidases of E. coli after translation. The properties of recombinant G-enzyme were similar to those of the enzyme from K-1 cells.