Effect of polyamines on mesangial cell ecto-5'-nucleotidase and ecto-ATPase activity

Polyamines were found to modulate the activity of several membrane-bound enzymes, participating in cell growth and differentiation. We have studied the effect of polyamines (spermidine, spermine and putrescine) on rat mesangial cell ectoenzymes: 5'-nucleotidase, Mg(2+)-ATPase and Ca(2+)-ATPase. Ecto-5'-nucleotidase activity was significantly increased after 48 h treatment with spermine and spermidine. Mg(2+)-ATPase was increased only after treatment with spermidine; however, Ca(2+)-ATPase was significantly increased after both spermine and spermidine treatment of mesangial cells. Culture of mesangial cells with putrescine did not change the activity of these ectoenzymes. Increased expression of mesangial cell ecto-ATPase and ecto-5'-nucleotidase after spermine and spermidine treatment could result in an increased production of adenosine, a powerful autacoid interesting with respect to a role of mesangial cells in inflammatory processes.     

Odorant differentiated pattern of cerebral activation: comparison of acetone and vanillin

Whether different odorous compounds (odorants) are processed by different cerebral circuits is presently unknown. A first step to address this complicated issue is to investigate how the cerebral regions mediating signals from olfactory (i.e., unimodal) odorants, differ from those mediating the olfactory + trigeminal (i.e., bimodal) odorants. [15O]-H2O-PET scans were conducted in 12 healthy females during three separate conditions: birhinal, passive smelling of: 1) the unimodal odorant vanillin; 2) the bimodal odorant acetone; and 3) odorless air. Significant activations were calculated contrasting vanillin to air, acetone to air, and deactivations, running these contrasts in the opposite direction. Smelling of vanillin activated bilaterally the amygdala and piriform cortex. These regions were only engaged slightly by acetone. Instead, strong activations were found in the anterior and central insula and claustrum, the posterior portion of anterior cingulate, the somatosensory cortex (SI for face), cerebellum, ventral medial (VMPo) and dorsal medial (MDvc) thalamus, the lateral hypothalamus, and pons/medulla. In parallel, the somatosensory (SI, below central representation of face), secondary visual and auditory cortices, as well as the supplementary motor area and the parahippocampal gyri were deactivated. No deactivations were observed with vanillin, although the odor components of acetone and vanillin were rated similarly intense (75 +/- 17 mm vs. 61 +/- 22 mm, NS). The differentiated pattern of cerebral activation during odorant perception seems to be dependent on the signal transducing cranial nerves involved. In contrast to vanillin, which solely activates the olfactory cortex, acetone engages predominantly trigeminal projections from the nasal mucosa. Acetone's limited activation of the olfactory cortex may result from a cross-modal interaction, with inhibition of acetone's odor component by its trigeminal component.     

Organisation of the sympathetic skin response in spinal cord injury

OBJECTIVES: The sympathetic skin response (SSR) is a technique to assess the sympathetic cholinergic pathways, and it can be used to study the central sympathetic pathways in spinal cord injury (SCI). This study investigated the capacity of the isolated spinal cord to generate an SSR, and determined the relation between SSR, levels of spinal cord lesion, and supraspinal connections. METHODS: Palmar and plantar SSR to peripheral nerve electrical stimulation (median or supraorbital nerve above the lesion, and peroneal nerve below the lesion) were recorded in 29 patients with SCI at various neurological levels and in 10 healthy control subjects. RESULTS: In complete SCI at any neurological level, SSR was absent below the lesion. Palmar SSR to median nerve stimuli was absent in complete SCI with level of lesion above T6. Plantar SSR was absent in all patients with complete SCI at the cervical and thoracic level. In incomplete SCI, the occurrence of SSR was dependent on the preservation of supraspinal connections. For all stimulated nerves, there was no difference between recording from ipsilateral and contralateral limbs. CONCLUSIONS: No evidence was found to support the hypothesis that the spinal cord isolated from the brain stem could generate an SSR. The results indicate that supraspinal connections are necessary for the SSR, together with integrity of central sympathetic pathways of the upper thoracic segments for palmar SSR, and possibly all thoracic segments for plantar SSR.     

International differences in ageing and spinal cord injury

DESIGN: The present study is part of a programme of longitudinal research on ageing and spinal cord injury involving three populations - American, British and Canadian. The design was multivariate. OBJECTIVE: To identify international differences in outcomes associated with ageing and spinal cord injury. SETTING: A sample of 352 participants was assembled from five large, well-established databases. The Canadian sample was derived from the member database of the Canadian Paraplegic Association (Ontario and Manitoba divisions). The British sample was recruited from Southport Hospital's Northwest Regional Spinal Injuries Centre and Stoke-Mandeville Hospital's National Spinal Injuries Centre. The American sample has been recruited through Craig Hospital in Denver, Colorado. METHODS: The sample included individuals who had incurred a spinal cord injury at least 20 years previously; were admitted to rehabilitation within 1 year of injury; were between age 15 and 55 at the time of injury. Data were collected using a combination of self-completed questionnaires and interviews. Data included medical information, general health, hospitalisations, and changes in bladder and bowel management, equipment, pain, spasticity, the need for assistance, and other health issues. RESULTS: Clear international differences existed between the three samples in the three different countries. After controlling for sampling differences (ie, differences in age, level of lesion, duration of disability, etc.), the following differences were seen: (1) American participants had a better psychological profile and fewer health and disability-related problems; (2) British participants had less joint pain and less likelihood of perceiving they were ageing more quickly; (3) Canadians had more health and disability-related complications (particularly bowel, pain and fatigue problems). CONCLUSION: These differences are discussed in terms of socio-political, health care system and cultural factors that might be used to explain them, and to generate hypotheses for future research.     

Hospital readmissions in people with chronic spinal cord injury

STUDY DESIGN: Longitudinal observational. OBJECTIVES: To examine frequency and duration of hospital readmissions in a population based sample of people with chronic spinal cord injury (SCI) and to look at medical reasons necessitating readmissions and factors influencing them. SETTING: National Spinal Injuries Centre, Stoke Mandeville Hospital, Aylesbury, UK and Regional Spinal Injuries Centre, District General Hospital, Southport, UK. METHODS: One-hundred-and-ninety-eight SCI patients, all injured more than 20 years ago, were interviewed on three occasions and their medical records reviewed for the period 1990 - 1996. RESULTS: Between 1990 and 1996, 127 patients (64% of the sample) required hospital treatment for late medical complications, with 481 readmissions between them and the mean length of stay of 12.03 days per readmission. Only 58% of all readmissions were into specialised spinal injuries centres. Averaged over the entire sample, the readmission rate was 0.4 readmissions per person at risk per year, and the occupancy rate was 4.9 bed-days per person at risk per year. The most frequent reason for readmissions were urinary tract complications (40.5% of all readmissions) and the highest bed occupancy was for skin problems (32.2% of all bed-days). When compared with the non-hospitalised group (36% of the sample), the readmitted patients had longer duration of paralysis and lower disability and handicap scores as measured by Functional Independence Measure (FIM) and Craig Handicap Assessment & Reporting Technique (CHART). The subgroups did not differ significantly by neurological grouping or age. CONCLUSIONS: Urinary and skin complications are the two main reasons for hospital readmissions in people with chronic SCI. Risk of readmissions increases with time since injury and with disability and handicap severity. Hospital bed requirements for people with chronic SCI are greater than the amount of clinical provision currently available in specialised spinal centres. In order to meet the needs of the growing SCI population, more specialised spinal injuries care beds will be needed. Spinal Cord (2000) 38, 371 - 377.     

Occupational intoxication with carbon monoxide

The most important safety measure for prevention of CO poisoning is the installation of automatic systems that signal high CO concentrations in the work environment. Public health measures that include stringent pollution control, introduction of low-cost CO monitors, and public education aimed at the high-risk population (e.g., new workers, drivers) should decrease the number of deaths from CO poisoning and should save productive years of life. Toxicity of CO is a consequence of tissue hypoxia created by the displacement of oxygen from hemoglobin and the subsequent impairment of oxygen release to the tissues. Early symptoms of CO intoxication are insidious and can resemble other diseases; physical examination may be unremarkable. For these reasons, many cases of CO poisoning are not readily recognized.     

Possibilities and limitations of fibrin glue usage in nephron-sparing surgery: experimental study

INTRODUCTION: The possibilities and limitations of fibrin glue (FG) usage in nephron-sparing surgery were studied. MATERIALS AND METHODS: A prospective experimental study was carried out in 50 pigs: 30 with polar resection, and 20 with mediorenal wedge resection of the kidney. Hemostatic sutures, FG, and FG with a muscle 'cup' in animals with polar resection of the kidney were compared. FG and sutures in animals with the wedge resection of the kidney were studied as well. Bleeding, hot ischemia time, complication rate, and additional scarring were also analyzed. RESULTS: Suture hemostasis is safe but with significant adverse effects in both polar and wedge resection of kidney. FG was not efficient as a sole hemostatic agent for polar resection. It was as efficient as hemostatic suture for wedge resection of the kidney. FG with a muscle 'cup' on a pole of the kidney achieved good results in animals with polar resection of the kidney. Histological analysis confirmed better results with FG because of both the less intense and smaller area of additional scarring. CONCLUSION: FG is a reliable and efficient hemostatic agent for nephron-sparing surgery whenever both sided gluing is possible.     

Predicting normal lung function in patients with childhood spinal cord injury

STUDY DESIGN: A prospective observational study. OBJECTIVES: To compare the height and arm span measurements in childhood spinal cord injured (SCI) people and examine the subsequent effect on calculating the predicted lung function using standard formulae and to discuss which of the two measurements is the most appropriate to use in these formulae. SETTING: National Spinal Injuries Centre, Stoke Mandeville Hospital, Aylesbury, UK. METHOD: A total of 12 children had lung function tests performed and at the same time had height and armspan measured. The predicted lung function was calculated twice; once using height and then using arm span and compared. The actual lung function test results were expressed as percentage of the two predicted values, respectively, and compared. RESULTS: The difference between the mean height (1499 mm) and arm span (1649 mm) measurements was significant (P<0.001). In all cases, the arm span measurement was greater than the height. The two predicted lung function values (one calculated using height and the other armspan) were significantly different (P<0.001). When lung function test results were expressed as percentage of the two predicted values they gave a very different interpretation of the results. The actual performance was much lower than the predicted values if arm span, rather than height, was used in prediction equations. CONCLUSION: In childhood SCI, the difference in height and arm span is significant. This affects the predicted lung function values significantly and thus changes the interpretation of the lung function test results. The most appropriate measurement to use in prediction equations (height or arm span) in these subjects is yet to be decided.