The Comparative Accuracy of BISAP and PANC3 Scoring System for the Disease Severity and Outcome in Acute Pancreatitis in Tertiary Care Hospital from North India

Background Acute pancreatitis has local and systemic manifestations, so it's important to assess the severity by various scoring system. Among them bed side index for severity of acute pancreatitis and pancreatitis three score have been considered to be more predictive and easier. Objective To determine the comparative prognostic value of bed side index for severity of acute pancreatitis and pancreatitis 3 score and its correlation with the outcome. Method A prospective observational study was conducted on 50 cases of acute pancreatitis. The patients were assessed clinically, radiologically and biochemically and were categorised into mild, moderate and severe category as per Atlanta Classification. Bed side index for severity of acute pancreatitis and pancreatitis 3 score was calculated at the time of admission and followed till the time of discharge or they had mortality. Result Receiver operating characteristic curve, showed bed side Index for severity of acute pancreatitis score had sensitivity (66.67%), specificity (84.09%), diagnostic accuracy (84%) while pancreatitis 3 score had sensitivity (50%), specificity (81.82%), diagnostic accuracy (80%) for the severity of acute pancreatitis. Bed side index for severity of acute pancreatitis had sensitivity (100%), specificity (66.67%) and Pancreatitis 3 score had sensitivity (66.67%), specificity (80.85%) for predicting the mortality in acute pancreatitis. Conclusion Bed side index for severity of acute pancreatitis and pancreatitis 3 score are both simple, bedside tool for assessing the severity and mortality but bed side index for severity of acute pancreatitis score had better sensitivity, specificity for assessing the severity and mortality as compared to pancreatitis three score.

Medical Pedagogy in the Time of COVID-19

Medical teaching is about giving a student a collaborative experience of the art and skill of the practice of medicine. This is acquired through authentic patient experiences. A clinical teacher uses clinical lectures, simulations, lab sessions, small group interactions, cadaver dissection and technical classes (eg: ultrasound) to create a complete clinical immersion experience. For this we use both the in-patient and out-patient facilities.

Amphetamine affects the behavioral outcome of lateral fluid percussion brain injury in the rat

This study examined the effects of (D)-amphetamine, methoxamine (an al-adrenergic receptor agonist), and prazosin (an al-adrenergic receptor antagonist) on the behavioral outcome of lateral fluid percussion brain injury. Rats trained to perform a beam walking task were subjected to brain injury of moderate severity (2.1-2.2 atm). At 10 min after injury, rats were treated with amphetamine, methoxamine or prazosin at two different dose levels. Amphetamine-treated animals displayed significantly lower impairment in beam walking ability from days 1 to 5 after brain injury. Neither methoxamine nor prazosin significantly affected the impairment in beam walking ability from day 1 to day 7 after injury. However, prazosin treatment at both dose levels increased the post-injury mortality and the incidences of failure to recovery from hemiplegia. Amphetamine-treatment at 4 mg/kg, but not at 2 mg/kg, improved the spatial learning abilities of the injured animals. Neither methoxamine nor prazosin affected the spatial learning abilities. These results indicate that amphetamine facilitated beam walking recovery and improved cognitive function after concussive fluid percussion injury. Although the methoxamine experiments suggest that the norepinephrine-α1-adrenergic receptor system may not be involved in the pathophysiology of fluid percussion brain injury, our results with amphetamine (beneficial effects) and prazosin (deleterious effects) and the results observed in other models of brain injury point out that further investigations are necessary to understand the role of a1-adrenergic receptors in brain injury.

Valgus extension overload syndrome of the elbow in a test cricket fast bowler

No Abstract South African Journal of Sports Medicine Vol. 20 (4) 2008: pp. 119-120

Regional expression of Par-4 mRNA and protein after fluid percussion brain injury in the rat

Regional levels of prostate apoptosis response-4 (Par-4) protein and mRNA were measured after lateral fluid percussion (FP) brain injury in rats. Immunochemical studies indicated that Par-4 immunoreactivity (ir) is present in cortical neurons and hippocampal CA1-CA3 pyramidal neurons in uninjured rats. Increases of Par-4-ir were observed in the CA3 neurons of the ipsilateral hippocampus (IH), but not in injured left cortex (IC) at 48 h after FP brain injury. Levels of the Par-4 mRNA measured by RT-PCR assay and protein measured by Western blot procedure were significantly increased in the injured IC and IH, but not in the contralateral right cortex and hippocampus after brain injury. Levels of both Par-4 protein and mRNA were significantly increased in the IC and IH as early as 2 h and stayed elevated at 24 and 48 h after injury. These data show that the induction of proapoptotic Par-4 mRNA and protein occurs only in the IC and IH that have been observed to undergo apoptosis and neuronal cell loss after lateral FP brain injury. Because increased expression of Par-4 has been observed to contribute to apoptosis and cell death in cultured neurons, the present temporal pattern of Par-4 expression is consistent with a role for Par-4 in apoptosis and neuronal cell death after traumatic brain injury.

Effects of chronic ethanol administration on expression of BDNF and trkB mRNAs in rat hippocampus after experimental brain injury

Previous evidence indicates that both chronic alcohol treatment and traumatic brain injury modulate expression of certain neurotrophins and neurotrophin receptors in cortical tissue. However, the combined effects of chronic alcohol and brain trauma on expression of neurotrophins and their receptors have not been investigated. In the present study, we examined the effects of 6 weeks of chronic ethanol administration on lateral fluid percussion (FP) brain injury-induced alterations in expression of mRNAs for the neurotrophin brain-derived neurotrophic factor (BDNF) and its high affinity receptor, trkB, in rat hippocampus. In both the control- (pair-fed isocaloric sucrose) diet and the chronic ethanol-diet groups, unilateral FP brain injury induced a bilateral increase in levels of both BDNF and trkB mRNAs in the dentate gyrus granule cell layer, and of BDNF mRNA in hippocampal region CA3. However, no significant differences in expression were found between the control-diet and ethanol-diet groups, in either the sham-injured or FP-injured animals. These findings suggest that 6 weeks of chronic ethanol administration does not alter the plasticity of hippocampal BDNF/trkB expression in response to experimental brain injury.

Three months of chronic ethanol administration and the behavioral outcome of rats after lateral fluid percussion brain injury

This study examined the effects of 3 months of chronic ethanol administration (CEAn) on the behavioral outcome in rats after lateral fluid percussion (FP) brain injury. Rats were given either an ethanol liquid diet (ethanol diet groups) or a pair-fed isocaloric sucrose control diet (control diet groups) for 3 months. Then, rats from both diet groups were subjected to either lateral FP brain injury of moderate severity (1.8 atm) or to sham operation. Postinjury behavioral measurements revealed that brain injury caused significant spatial learning disability in both diet groups. There were no significant differences in spatial learning ability in the sham or brain-injured animals between the control and ethanol diets. However, a trend towards cognitive impairment in the sham animals and a trend towards reduced deficits in the brain-injured animals were observed in the ethanol diet group. Histologic analysis of injured animals from both diet groups revealed similar extents of ipsilateral cortical and hippocampal CA3 damage. These results, in general, suggest that 3 months of CEAn does not significantly alter the behavioral and morphologic outcome of experimental brain injury.

Lactate and free fatty acids after subarachnoid hemorrhage

The hypothesis that lactate and free fatty acids (FFA) are elevated in the first minutes after subarachnoid hemorrhage (SAH) is tested. Adult rats were subjected to an endovascular SAH through the right internal carotid artery while under anesthesia. The brains were frozen in-situ at 15, 30, 60 min, and 24 h post-hemorrhage. Regional measures of tissue lactic acid and FFA were made in the hippocampi, ipsilateral cortex, contralateral cortex, and cerebellum. Lactic acid levels were significantly elevated from sham animals in each region within the first hour (p<0.0001 cerebellum, right, and contralateral cortex, p<0.01 hippocampus), but did not change significantly over the first hour. At 24 h post-hemorrhage, there was no significant difference in the lactic acid levels from controls. Similarly, total FFA were significantly higher in each region as compared to sham operated controls within the first hour (p<0.001 cerebellum, p<0.05 hippocampus, p<0.05 contralateral cortex, p<0.0001 ipsilateral cortex). By 24 h, there was no significant difference in FFA levels from shams. The data indicate that aerobic metabolism fails and cellular damage with degradation of cell membranes occurs in the first minutes after SAH, and lasts for at least 1 h. However, this process is stabilized within 24 h in our model. Although the largest effect was seen in the ipsilateral cortex, all areas of the brain were effected.

Immunohistochemical detection of the lipid peroxidation product 4-hydroxynonenal after experimental brain injury in the rat

This study examined the accumulation of the cytotoxic lipid peroxidation product 4-hydroxynonenal (HNE) after lateral fluid percussion (FP) brain injury in rats. A diffuse distribution of HNE-immunoreactivity (HNE-ir) was observed in the cortex and hippocampus of the ipsilateral, but not of the contralateral, hemisphere at 30 min, 6 h, 24 h, and 48 h after brain injury. The HNE-ir was well-localized in cell bodies of the ipsilateral cortex and the CA3 pyramidal layer in the ipsilateral hippocampus. Because HNE's interaction with certain proteins causes protein dysfunction and HNE, in vitro, causes neuronal cell damage, the present results suggest that HNE's interaction with neuronal proteins may contribute to neuronal damage in the ipsilateral cortex and hippocampus after brain injury.

Kynurenate attenuates the accumulation of diacylglycerol and free fatty acids after experimental brain injury in the rat

This study examined the effects of the administration of kynurenate, a non-specific excitatory amino acid (EAA) receptor subtype antagonist, on the regional accumulation of diacylglycerol (DG) and free fatty acids (FFAs) after lateral fluid percussion (FP) brain injury in the rat. After brain injury of moderate severity (2.0 atm), rats were treated with either kynurenate (200 mg/kg, i.v.) or saline at 5 min after injury. In the saline-treated brain-injured rats, levels of all individual DG-fatty acids (palmitic, stearic, oleic and arachidonic acids) and total DG-fatty acids were increased in the ipsilateral left cortex and hippocampus at 30 min and 60 min after injury. Kynurenate administration attenuated increases of individual and total DG-fatty acids in the ipsilateral cortex at 30 and 60 min and in the ipsilateral hippocampus at 30 min after FP brain injury. At 30 and 60 min after FP brain injury, increases in the levels of individual FFAs (palmitic, stearic, oleic and arachidonic acids) and of total FFAs were also observed in the ipsilateral cortex and hippocampus of the saline-treated injured rats. Kynurenate administration attenuated increases of all individual and total FFAs in the ipsilateral cortex and hippocampus either at 30 min alone or at both 30 min and 60 min after FP brain injury. In the contralateral cortex, levels of both DG-fatty acids and FFAs were not increased in the saline-treated injured rats and were also not affected by the administration of kynurenate. These results support the role of EAA receptor subtypes in the phospholipases-catalyzed formation of DG and FFAs in the ipsilateral cortex and hippocampus after lateral FP brain injury.

Alterations in BDNF and trkB mRNA levels in the cerebral cortex following experimental brain trauma in rats

Recent studies have suggested that brain-derived neurotrophic factor (BNDF) and its receptor, trkB, may provide neuroprotection following injury to the central nervous system. Conversely, other studies have implicated BDNF as a contributing factor to neurodegenerative events that occur following injury. In order to further investigate the role of BDNF in neuroprotection, we subjected adult rats to a lateral fluid percussion (FP) injury of moderate severity (2.0-2.1 atm) or sham injury. After survival periods of 1, 3, 6, 24, or 72 h, the brains were processed for the in situ hybridization localization of BDNF and trkB mRNAs using 35S-labeled cRNA probes. Hybridization levels were compared between injured and sham animals for regions of the cortex that were located within, adjacent to, and remote from the site of the cortical contusion. BDNF mRNA levels were significantly decreased in the injured cortex at 72 h, increased in adjacent cortical areas at 3 h, and increased bilaterally in the piriform cortex from 3 to 24 h post-FP injury. Expression of trkB mRNA was significantly decreased at all postinjury time-points in the injured cortex and at 24 h in the adjacent cortex. These results demonstrate that, following lateral FP injury, BDNF and trkB mRNA levels are decreased in cortical regions that contain degenerating neurons, generally unchanged in adjacent regions, and increased in remote areas. Thus, injury-induced decreases in the expression of BDNF and trkB may confer vulnerability to neurons within the cortical contusion.

Severity of experimental brain injury on lactate and free fatty acid accumulation and Evans blue extravasation in the rat cortex and hippocampus

Lactate and free fatty acids (FFAs) were extracted from the cortices and hippocampi of rats subjected to sham operation, or mild (1.25 atm) or moderate (2.0 atm) fluid percussion (FP) injury, and their total tissue concentrations were measured. The elevation of lactate in the injured left cortex (IC) and ipsilateral hippocampus (IH) was significantly greater in the moderate-injury than in the mild-injury group at most test times between 5 min and 48 h after injury. Levels of total FFAs were elevated in the IC and IH to a greater extent and for a longer period after injury in the moderate-injury (up to 48 h) than in the mild-injury group (up to 20 min). In general, the extent and duration of the elevation of most of the individual FFAs (palmitic, stearic, oleic, and arachidonic acids) in the IC and IH were also greater in the moderate-injury group than in the mild-injury group. In the contralateral cortex (CC) and hippocampus (CH), the elevation of lactate and total FFAs (and individual stearic and arachidonic acids) were also greater in the moderate-injury group than in the low-injury group at 5 min after injury. The extravasation of Evans blue in the IC and IH from 3 to 6 h after injury was also the greatest in the moderate-injury group. The hippocampal CA3 neuronal cell loss, but not cortical lesion volume, also increased with the severity of injury. These findings suggest that certain neurochemical, physiological (blood-brain barrier permeability), and morphologic responses increase with the severity of FP brain injury, and such relationships are consistent with the increased behavioral deficits observed with the increase of severity of brain injury.

Regional activities of phospholipase C after experimental brain injury in the rat

Regional activities of phosphoinositide-specific phospholipase C (PLC) were measured after lateral fluid percussion (FP) brain injury in rats. The activity of PLC on phosphatidylinositol 4,5-bisphosphate (PIP2) in the rat cortex required calcium, and at 45 microM concentration it increased PLC activity by about ten-fold. The activity of PLC was significantly increased in the cytosol fraction in the injured (left) cortex (IC) at 5 min, 30 min and 120 min after brain injury. However, in the same site, increases were observed in the membrane fraction only at 5 min after brain injury. In both the contralateral (right) cortex (CC) and ipsilateral hippocampus (IH), the activity of PLC was increased in the cytosol only at 5 min after brain injury. These results suggest that increased activity of PLC may contribute to increases in levels of cellular diacylglycerol and inositol trisphosphate in the IC (the greatest site of injury), and to a smaller extent in the IH and CC, after lateral FP brain injury. It is likely that this increased PLC activity is caused by alteration in either the levels or activities of one or more of its isozymes (PLCbeta, PLCgamma, and PLCdelta) after FP brain injury.

Effects of six weeks of chronic ethanol administration on the behavioral outcome of rats after lateral fluid percussion brain injury

This study examined the effects of 6 weeks of chronic ethanol administration on the behavioral outcome in rats after lateral fluid percussion (FP) brain injury. Rats were given either an ethanol liquid diet (ethanol diet-groups) or a pair-fed isocaloric sucrose control diet (control diet groups) for 6 weeks. After 6 weeks, the ethanol diet was discontinued for the ethanol diet rats and they were then given the control sucrose diet for 2 days. During those 2 days, the rats were trained to perform a beam-walking task and subjected to either lateral FP brain injury of low to moderate severity (1.8 atm) or to sham operation. In both the control diet and the ethanol diet groups, lateral FP brain injury caused beam-walking impairment on days 1 and 2 and spatial learning disability on days 7 and 8 after brain injury. There were no significant differences in beam-walking performance and spatial learning disability between brain injured animals from the control and ethanol diet groups. However, a trend towards greater behavioral deficits was observed in brain injured animals in the ethanol diet group. Histologic analysis of both diet groups after behavioral assessment revealed comparable ipsilateral cortical damage and observable CA3 neuronal loss in the ipsilateral hippocampus. These results only suggest that chronic ethanol administration, longer than six weeks of administration, may worsen behavioral outcome following lateral FP brain injury. For more significant behavioral and/or morphological change to occur, we would suggest that the duration of chronic ethanol administration must be increased.

Regional levels of phospholipase Cgamma after fluid percussion brain injury in the rat

Levels of PLCgamma, a phospholipase C (PLC) isozyme, were significantly increased in the cytosol in the injured left cortex (LC) at 5, 30 and 120 min after brain injury. In the same site, although levels of membrane PLCgamma did not alter at 5 and 30 min, they were found to be decreased at 2 h after brain injury. In general, the levels of both cytosolic and membrane PLCgamma were unaltered in the contralateral right cortex (RC), ipsilateral left hippocampus (LH) and contralateral right hippocampus (RH) between 5 and 120 min after brain injury. These results suggest that, in addition to well-proposed excitatory neurotransmitter-receptor systems, increased levels of PLCgamma may also contribute to alterations in PIP2 signal transduction pathway, particularly in the greatest injury site (LC) after lateral FP brain injury.

Amphetamine administration improves neurochemical outcome of lateral fluid percussion brain injury in the rat

This study examined the effects of the administration of D-amphetamine on the regional accumulation of lactate and free fatty acids (FFAs) after lateral fluid percussion (FP) brain injury in the rat. Rats were subjected to either FP brain injury of moderate severity (1.9 to 2.0 atm) or sham operation. At 5 min after injury, rats were treated with either d-amphetamine (4 mg/kg, i.p.) or saline. At 30 min and 60 min after brain injury, brains were frozen in situ, and cortices and hippocampi were excised at 0 degrees C. In the saline-treated brain injured rats, levels of lactate were increased in the ipsilateral left cortex and hippocampus at 30 min and 60 min after injury. These increases were attenuated by the administration of D-amphetamine at 5 min after lateral FP brain injury. At 30 and 60 min after FP brain injury, increases in the levels of all individual FFAs (palmitic, stearic, oleic and arachidonic acids) and of total FFAs were also observed in the ipsilateral cortex of the saline-treated injured rats. These increases in the ipsilateral cortex and hippocampus were also attenuated by the administration of d-amphetamine. Neither levels of lactate nor levels of FFAs were increased in the contralateral cortex in the saline-treated injured rats at 30 min or 60 min after FP brain injury. The levels of lactate and FFAs in the contralateral cortex were also unaffected by the administration of D-amphetamine. These results suggest that the attenuation of increases in the levels of lactate and FFAs in the ipsilateral cortex and hippocampus may be involved in the amphetamine-induced improvement in behavioral outcome after lateral FP brain injury.

Expression of trkB mRNA is altered in rat hippocampus after experimental brain trauma

Recent investigations have shown that expression of mRNAs for the neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) is differentially altered in the hippocampus following traumatic brain injury. In the present study, modulation of neurotrophin receptor expression was examined in the hippocampus in a rat model of traumatic brain injury using in situ hybridization. Messenger RNA for trkB, the high-affinity receptor for BDNF and neurotrophin-4 (NT-4), was increased between 3 and 6 h bilaterally in the dentate gyrus following a lateral fluid-percussion brain injury of moderate severity (2.0-2.1 atm). No time-dependent alterations were observed for trkB mRNA in hippocampal subfields CA1 and CA3. Levels of mRNA for trkC, the high-affinity receptor for NT-3, did not change in any region of the hippocampus. These data demonstrate that lateral fluid-percussion injury modulates expression of trkB mRNA in the hippocampus and support a role for BDNF/trkB signalling mechanisms in secondary events associated with traumatic brain injury.

Effects of six weeks of chronic ethanol administration on lactic acid accumulation and high energy phosphate levels after experimental brain injury in rats

The effects of 6 weeks of chronic ethanol administration on the lateral fluid percussion (FP) brain injury-induced regional accumulation of lactate and on the levels of total high-energy phosphates were examined in rats. In both the chronic ethanol diet (ethanol diet) and pair-fed isocaloric sucrose control diet (control diet) groups, tissue concentrations of lactate were elevated in the cortices and hippocampi of both the ipsilateral and contralateral hemispheres at 5 min after brain injury. In both diet groups, concentrations of lactate were elevated only in the injured left cortex and the ipsilateral hippocampus at 20 min after FP brain injury. No significant differences were found in the levels of lactate in the cortices and hippocampi of sham animals and brain-injured animals between the ethanol and control diet groups at 5 min and 20 min after injury. In the ethanol and control diet groups, tissue concentrations of total high-energy phosphates (ATP + PCr) were not affected in the cortices and hippocampi at 5 min and 20 min after lateral FP brain injury. No significant differences were found in the levels of total high-energy phosphates in the cortices and hippocampi of the sham and brain-injured animals between the ethanol and control diet groups at 5 min and 20 min after injury. Histologic studies revealed a similar extent of damage in the cortex and in the CA3 region of the ipsilateral hippocampus in both diet groups at 14 days after lateral FP brain injury. These findings suggest that 6 weeks of chronic ethanol administration does not alter brain injury-induced accumulation of lactate, levels of total high energy phosphates, and extent of morphological damage.

Alterations in BDNF and NT-3 mRNAs in rat hippocampus after experimental brain trauma

Previous studies have suggested that the neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) are neuroprotective or neurotrophic for certain subpopulations of hippocampal neurons following various brain insults. In the present study, the expression of BDNF and NT-3 mRNAs in rat hippocampus was examined after traumatic brain injury. Following lateral fluid percussion (FP) brain injury of moderate severity (2.0-2.1 atm) or sham injury, the hippocampi from adult rats were processed for the in situ hybridization localization of BDNF and NT-3 mRNAs using 35S-labeled cRNA probes at post-injury survival times of 1, 3, 6, 24 and 72 h. Unilateral FP injury markedly increased hybridization for BDNF mRNA in the dentate gyrus bilaterally which peaked at 3 h and remained above control levels for up to 72 h post-injury. A moderate increase in BDNF mRNA expression was also observed bilaterally in the CA3 region of the hippocampus at 1, 3, and 6 h after FP injury, but expression declined to control levels by 24 h. Conversely, NT-3 mRNA was significantly decreased in the dentate gyrus following FP injury at the 6 and 24 h survival times. These results demonstrate that FP brain injury differentially modulates expression of BDNF and NT-3 mRNAs in the hippocampus, and suggest that neurotrophin plasticity is a functional response of hippocampal neurons to brain trauma.

Time course of changes in lactate and free fatty acids after experimental brain injury and relationship to morphologic damage

Regional levels of lactate and free fatty acids (FFA) were measured after lateral fluid percussion (FP) brain injury in rats. At 5 min after injury, tissue concentrations of lactate were elevated in the cortices and hippocampi of both ipsilateral and contralateral hemispheres. Whereas lactate levels had returned to normal by about 20 min after injury in the penumbra and contralateral cortices, their elevation persisted in the ipsilateral injured cortex and hippocampus for 24 h after injury. Increases in the levels of FFA (particularly stearic and arachidonic acids) were observed in the cortices and hippocampi of both ipsilateral and contralateral hemispheres at 5 min after injury; these levels returned to normal in only the penumbra and contralateral cortices by 20 min after injury. Increased amounts of palmitic and oleic acids were also found only in the injured left cortex and ipsilateral hippocampus at 20 min or later after injury. In general, these elevations persisted for as long as 6 to 24 h in the injured cortex and for 2.5 to 24 h after injury in the ipsilateral hippocampus. Histologic studies revealed a similar extent of damage in the cortex between 5 min and 24 h after injury, whereas damage in the CA3 region of the ipsilateral hippocampus increased during that period. These findings suggest a role for lactic acid and FFA, two secondary injury factors, in neuronal cell loss after brain injury.

Lack of delayed effects of amphetamine, methoxamine, and prazosin (adrenergic drugs) on behavioral outcome after lateral fluid percussion brain injury in the rat

This study examined the delayed effects of the administration of d-amphetamine, methoxamine (an alpha1-adrenergic receptor agonist), and prazosin (an alpha1-adrenergic receptor antagonist) on the behavioral outcome of lateral fluid-percussion (FP) brain injury. Rats trained to perform a beam-walking task were subjected to brain injury of moderate severity (2.1 to 2.2 atm). Twenty-four hours after injury, rats were treated with amphetamine, methoxamine, or prazosin at two or three different dose levels. Amphetamine-treated animals displayed no significant improvement in beam-walking ability either during or after drug intoxication (from days 3 to 5 after brain injury). Similarly, neither methoxamine nor prazosin significantly affected beam-walking ability during or after drug intoxication. Neither amphetamine treatment at three different doses nor treatment with methoxamine or prazosin at two different doses affected the spatial learning disabilities of brain-injured animals. These results suggest that (1) unlike amphetamine administration after sensorimotor cortex (SMC) ablation or contusion brain injury models, amphetamine administration at 24 h after concussive FP brain injury does not improve beam-walking performance; (2) unlike amphetamine administration 10 min after concussive FP brain injury amphetamine administration 24 h after injury does not improve cognitive function; and (3) unlike prazosin administration after SMC ablation brain injury, prazosin administration 24 h after concussive FP brain injury does not effect beam-walking performance.

Effects of muscarinic receptor antagonism on the phosphatidylinositol bisphosphate signal transduction pathway after experimental brain injury

Hippocampal levels of fatty acids extracted from phosphatidylinositol 4,5-bisphosphate (PIP2), free fatty acids (FFA), and lactate were measured after central fluid percussion traumatic brain injury (TBI) in rats. At 5 min after injury, there was a decrease in fatty acids extracted from PIP2 suggesting a decrease in PIP2. At the same time point, total FFA increased in saline-treated TBI rats. Levels of arachidonic acid were significantly decreased in PIP2, while at the same time arachidonic and stearic acids increased in FFA in saline-treated TBI rats. No significant alterations in PIP2-derived fatty acids or FFA were observed at 20 min after TBI. Hippocampal concentrations of lactate were significantly elevated at 5 and 20 min after injury in saline-treated rats. In general, these alterations were blunted by preinjury administration of the muscarinic antagonist, scopolamine. These results suggest that the PIP2 signal transduction pathway is activated in the hippocampus at the onset of central fluid percussion TBI and that the enhanced phospholipase C-catalyzed phosphodiestric breakdown of PIP2 is a major mechanism of liberation of FFA in these sites immediately after such injury. The blunting of PIP2 and FFA alterations in animals treated with scopolamine suggests that activation of muscarinic receptors significantly contributes to the phospholipase C (PLC) signal transduction pathophysiology in TBI. The attenuation of lactate accumulation in scopolamine-treated rats suggests that TBI-induced muscarinic receptor activation also contributes to increased glycolytic metabolism and/or ionic imbalances.

Regional generation of leukotriene C4 after experimental brain injury in anesthetized rats

Regional concentrations of leukotriene C4 and extravasation of Evans blue were measured after lateral fluid-percussion brain injury in rats. Tissue levels of LTC4 were elevated in the injured cortex at 10 min, 30 min, and 1 h after injury; these levels returned to normal by 2 h after injury. Increases in the levels of LTC4 were also observed in the ipsilateral hippocampus after brain injury, and these elevations persisted for 2 h after injury. No significant increase in levels of LTC4 was observed in the contralateral cortex at any time after injury. A substantial extravasation of Evans blue was observed only in the ipsilateral cortex and hippocampus at 3 h and 6 h after brain injury. Although a temporal association between LTC4 and blood-brain barrier (BBB) breakdown is suggested by these data, no cause-and-effect relationship has been addressed in this study. However, it is possible that, as is true for cerebral ischemia, LTC4 may play a role as a mediator in the BBB breakdown associated with fluid-percussion brain injury in rats.

Alterations in brain protein kinase C after experimental brain injury

Regional activities and levels of protein kinase C were measured after lateral fluid percussion brain injury in rats. At 5 min and 20 min after injury, neither cofactor-dependent nor -independent PKC activities in the cytosol and membrane fractions changed in the injured and contralateral cortices or in the ipsilateral hippocampus. Western blot analysis revealed decreases in the levels of cytosolic PKC alpha and PKC beta in the injured cortex after brain injury. In the same site, a significant increase in the levels of membrane PKC alpha and PKC beta was observed after injury. Although the level of PKC alpha did not change and that of PKC beta decreased in the cytosol of the ipsilateral hippocampus, these levels did not increase in the membrane fraction after injury. The levels of PKC gamma were generally unchanged in the cytosol and the membrane, except for its decrease in the cytosol of the hippocampus. There were no changes in the levels of any PKC isoform in either the cytosol or the membrane of the contralateral cortex after injury. The present results suggest a translocation of PKC alpha and PKC beta from the cytosol to the membrane in the injured cortex after brain injury. The observation that such a translocation occurs only in the brain regions that undergo substantial neuronal loss suggests that membrane PKC may play a role in neuronal damage after brain injury.

Regional concentrations of cyclic nucleotides after experimental brain injury

Regional concentrations of lactate, glucose, cAMP, and cGMP were measured after lateral fluid percussion brain injury in rats. At 5 min after injury, while tissue concentrations of lactate were elevated in the cortices and hippocampi of both the ipsilateral and contralateral hemispheres, those of glucose were decreased in these brain regions. By 20 min after injury, increases of lactate concentrations and decreases of glucose concentrations were observed only in the cortices and in the hippocampus of the ipsilateral hemisphere. Whereas the cAMP concentrations were unchanged in the cortices and hippocampi of the ipsilateral and contralateral hemispheres at 5 min after injury, decreases were found in the injured cortex and ipsilateral hippocampus at 20 min after injury. The tissue concentrations of cGMP were found to be elevated only in the ipsilateral hippocampus at 5 min after injury. The present observation that tissue glucose decreases in the injured cortex and the ipsilateral hippocampus are consistent with the published findings of increased hyperglycolysis and oxidative metabolism in brain immediately after injury. The present findings that the concentrations of cAMP and cGMP change in the cortex and hippocampus provide biochemical evidence for the neurotransmitter's surge after brain injury.

Activation of phosphatidylinositol bisphosphate signal transduction pathway after experimental brain injury: a lipid study

Regional levels of phosphatidylinositol 4,5-bisphosphate (PIP2), diacylglycerol (DG) and free fatty acids (FFA), involved in the signal transduction pathway of the excitatory neurotransmitter system, were measured after lateral fluid percussion (FP) brain injury in rats. At 5 min postinjury, tissue PIP2 concentrations were significantly reduced in the cortices and hippocampi of both ipsilateral and contralateral hemispheres. Only levels of stearic and arachidonic acids were substantially decreased in PIP2 in these regions of the brain. At the same time after injury, both DG and FFA were significantly increased in the cortices and hippocampi of both hemispheres. As was true for PIP2, only levels of stearic and arachidonic acids markedly changed in both DG and FFA in these regions of the brain. At 20 min postinjury, a significant decrease in PIP2 concentration and significant increases in levels of DG and FFA were observed only in the injured left cortex. In addition to the increases in stearic and arachidonic acids in FFA, increased amounts of palmitic and oleic acids were also found in the injured left cortex at 20 min after injury. These results suggest that the PIP2 signal transduction pathway is activated in the cortex and hippocampus at the onset of lateral FP brain injury and that the enhanced phospholipase C-catalyzed phosphodiestric breakdown of PIP2 is a major mechanism of liberation of FFA in these sites immediately after such injury.

Regional levels of free fatty acids and Evans blue extravasation after experimental brain injury

The recently developed controlled cortical-impact (CCI) model of brain injury in rats serves as an excellent tool to understand some of the neurochemical mechanisms mediating the pathophysiology of traumatic brain injury. In this study, rats were subjected to lateral CCI brain injury of low-grade severity. Their brains were frozen in situ at various times after injury to measure regional levels of free fatty acids. Tissue total free fatty acids at the injury site within the left cortex were increased at 30 min, 2.5 h, and 24 h postinjury. In injured animals, increases in stearic and arachidonic acids were slightly greater than those in palmitic and oleic acids. The levels of total free fatty acids in the cortex adjacent to the injury site were also increased in injured animals at 2.5 h and 24 h after injury (p < 0.05). Only stearic and arachidonic acids were observed to be significantly increased (p < 0.05) in the adjacent cortex of injured animals at all times after injury. Although no significant increases in total free fatty acids were observed in the left hippocampus adjacent to the injury site, stearate and arachidonate concentrations were increased at 30 min and 2.5 h after injury (p < 0.05). Extravasation of Evans blue was found to be significantly increased in the ipsilateral cortex of injured animals at 30 min and 10 h after brain injury. These results indicate the degradation of membrane phospholipids and blood-brain barrier breakdown in the ipsilateral cortex after lateral CCI brain injury. These results also suggest that arachidonic acid and its metabolites may play a role as a mediator in the blood-brain barrier breakdown associated with cortical impact brain injury in rats.

Enhanced phosphodiestric breakdown of phosphatidylinositol bisphosphate after experimental brain injury

Regional levels of lactate and inositol 1,4,5-trisphosphate (IP3), a cellular second messenger of the excitatory neurotransmitter system, were measured after lateral fluid percussion (FP) brain injury in rats. At 5 min postinjury, tissue lactate concentrations were significantly elevated in the cortices and hippocampi of both the ipsilateral and contralateral hemispheres. By 20 min postinjury, lactate concentrations were elevated only in the cortices and hippocampus of the ipsilateral hemisphere. Whereas the IP3 concentrations were elevated in the hippocampi of the ipsilateral and contralateral hemisphere and in the cortex of ipsilateral hemisphere at 5 min postinjury, no elevation in these sites was found at 20 min postinjury. Histologic analysis revealed neuronal damage in the cortex and CA3 regions of hippocampus ipsilateral to the injury at 24 h postinjury. The present results suggest activation of the phosphoinositide signal transduction pathway at the onset of injury and of a possible requirement of early persistent metabolic dysfunction (> 20 min) such as the lactate accumulation in the delayed neuronal damage.

Importance of diurnal variations on clinical value and interpretation of serum urate measurements

AIM

To show the extent of diurnal variations in serum urate concentration and the possible consequences on the clinical interpretation.

METHODS

Nineteen controls and 40 patients took part in this study. Preliminary investigations on selected subjects provided blood samples at regular intervals between the hours of 0800 and 2300 hours. From these observations the timing of venepuncture for the remaining subjects was chosen at 0800-0900 hours, with a second sample taken between 1700 and 1800 hours. Analytical quality was monitored using quality control procedures and all samples were analysed in a single batch to minimise errors.

RESULTS

All subjects, except some hypertensive elderly women, showed a diurnal rhythm. The mean serum urate value between 0800-0900 hours was higher than that observed between 1700-1800 hours. A decrease of up to 30% was observed in a group of diabetic patients. Nine subjects in the study had hyperuricaemia in the morning, but only six in the afternoon, indicating the requirement of a reference interval that takes account of diurnal variations.

CONCLUSION

When studying the temporal relation for the medical importance, or when attempting to interpret the serum urate concentration, it is important to consider the diurnal rhythms of this analyte.

Health promotion and elderly people

By the year 2000, among the fastest growing population segment will be those over 60 years of age. The elderly population will be healthier and better educated than at any time in history. There will be many more elderly people who have both the capability and desire to continue leading a productive life at work. The World Health Organization recognizes both the importance of this growing segment of the world's population, their needs for services as well as health promotion.