Brain region- and metal-specific effects of embedded metals in a shrapnel wound model in the rat

The health effects of prolonged exposure to embedded metal fragments, such as those found in shrapnel wounds sustained by an increasing number of military personnel, are not well known. As part of a large collaborative effort to expand this knowledge, we use an animal model of shrapnel wounds originally developed to investigate effects of embedded depleted uranium to investigate effects of military-relevant metals tungsten, nickel, cobalt, iron, copper, aluminum, lead, and depleted uranium compared to an inert control, tantalum. Rats are surgically implanted with pellets of one of the metals of interest in the gastrocnemius (leg) muscle and tracked until 1 month, 3 months, 6 months, or 12 months from the time of implant, at which point they are euthanized and multiple organs and tissue samples are collected for inspection. Here we focus on four regions of the brain: frontal cortex, hippocampus, amygdala, and cerebellum. We examined changes in accumulated metal concentration in each region as well as changes in expression of proteins related to blood brain barrier tight junction formation, occludin and ZO-1, and synapse function, PSD95, spinophilin, and synaptotagmin. We report few changes in metal accumulation or blood brain barrier protein expression, but a large number of synapse proteins have reduced expression levels, particularly within the first 6 months of exposure, but there are regional and metal-specific differences in effects.

Temporal alterations in aquaporin and transcription factor HIF1α expression following penetrating ballistic-like brain injury (PBBI)

OBJECTIVES

Brain edema is a primary factor in the morbidity and mortality of traumatic brain injury (TBI). The various isoforms of aquaporin 4 (AQP4) and aquaporin 9 (AQP9) are important factors influencing edema following TBI. Others have reported that these AQPs are regulated by the transcription factor hypoxia inducible factor (HIF) 1α. Therefore, we examined the temporal alterations in the multiple isoforms of AQP4 and AQP9, and its possible upstream regulation by HIF1α, and evaluated whether different severities of penetrating injury influence these mechanisms.

METHODS

In the penetrating ballistic-like brain injury (PBBI) model, a temporary cavity and resultant injury was formed by the rapid inflation/deflation (i.e. <40ms) of an elastic balloon attached to the end of the custom probe, injuring 10% of total rat brain volume. Tissue from the ipsilateral core and perilesional injury zones was collected. Total RNA was isolated at 4, 12, and 24h, 3 and 7days post-injury (sham and PBBI, n=6 per group). cDNA was synthesized using oligodT primers. Quantitative real time PCR was performed using Taqman expression assays for aqp4 (recognizing all isoforms), aqp9, and hif1α. Using separate animals, tissue lysate was collected at 4 and 24h, 3 and 7days post-injury and analyzed by immunoblot for protein expression of multiple isoforms of AQP4, the single known isoform of AQP9 and for expression of transcription factor HIF1α (sham, probe only control, and PBBI, n=8-10 per group).

RESULTS

Global aqp4 mRNA was decreased at 24h (p<0.01) with PBBI. Three of the four known protein isoforms of AQP4 were detected, M1 (34kDa), M23 (32kDa) and isoform 3 (30kDa). AQP4 M1 decreased at 3 and 7days post-injury (p<0.001; p<0.01). AQP4 M23 levels were highly variable with no significant changes. AQP4 isoform 3 levels were decreased 3days post-PBBI (p<0.05). From 4, 12, and 24h aqp9 mRNA levels were decreased with injury (p<0.01, p<0.05, p<0.01) while AQP9 levels were decreased at 3 and 7days after PBBI (p<0.001, p<0.01). At 12 and 24h post-PBBI hif1α mRNA levels increased (p<0.05, p<0.01) but at 3 and 7days mRNA levels decreased (p<0.05, p<0.01). From 24h and 3 and 7days HIF1α protein levels were decreased (p<0.0001, p<0.0001, p<0.0001). In comparison to probe control, PBBI led to greater decreases in protein for AQP4 M1 (trend), AQP4 isoform 3 (trend), AQP9 (p<0.05) and HIF1α (p<0.05).

CONCLUSION

PBBI is characterized by a loss of AQP4 M1, AQP4 isoform 3 and AQP9 at delayed time-points. The severity of the injury (PBBI versus probe control) increased these effects. Therefore, AQP9 and the AQP4 M1 isoform may be regulated by HIF1α, but not AQP4 isoform 3. This delayed loss of aquaporins may markedly reduce the ability of the brain to efflux water, contributing to the protracted edema that is a characteristic following severe penetrating TBI. Factors contributing to edema differ with different types and severities of TBI. For example, cellular based edema is more prominent in diffuse non-penetrating TBI whereas vasogenic edema is more prevalent with TBI involving hemorrhage. Molecular regulation leading to edema will likely also differ, such that treatments which have been suggested for non-hemorrhagic moderate TBI, such as the suppression of aquaporins, may be detrimental in more severe forms of TBI.

[Membranes structure and physical and mechanical erythrocytes properties in the early period of traumatic brain injury caused by less-lethal firearms]

The dynamics of erythrocytes properties in the acute phase of traumatic brain injury caused by less-lethal firearms has been studied by the methods of atomic force and morphometry. The experiments have been performed on sheep by a Makarych pistol single shot at the parietooccipital area. It has been established that under the influence of the shock waves the erythrocyte disks and transmembrane liquid oscillatory fluctuations (flicker) are increased. The fluctuations are rapidly attenuated and the shock waves energy is accepted by cytoplasmic membranes lipoproteids. As a result the interface tlipid-protein, phase transitions are hastened. The membranes undergo heterogeneous structural, physical and mechanical transformations the character of which is determined by the phase transitions direction. In the spots of phospolipid liquid clusters accumulation the fluidity is increased and marks caused by membranes lamination and spreading appear. In the spots of phospholipids solid phase the surfaces become hydrophobic and marks caused by membranes local embrittlement and fragility appear. The transmembrane fluid hydrodynamic flows heterogeneity is increased due to deformation processes irregular spreading. The flows acceleration causes the hydrodynamic ruptures-like defects. The flows deceleration results in depressions evolving through the mechanism of creeping erosions.

Investigation of lead mobilization from the buckshot residues to the critical organs

Lead exposure causes neurotoxicity, reproductive system dysfunction, renal failure, and blood and endocrine system disorders in human and experimental animals. In this study, we investigated lead mobilization from gunshot fragments to the critical organs (brain, heart, liver, and kidney) and its interaction with essential trace elements on experimental rat model. Thirty-five rats were randomly divided in five groups. The first group was a control and the others were subjected to buckshot implantation in their skeletal muscles (second and third groups) and abdomen (fourth and fifth groups). The control group and the second and fourth groups were sacrificed 1 month after the onset of experiment while the third and fifth groups were followed after 2 months. Blood lead levels were significantly elevated in both 2 month-followed groups and 1 month-followed intraabdominal group. There were significant increases in brain lead levels of both 2 month-followed groups. For the 1 month-followed groups, kidney lead levels were also significantly higher than those of controls. Results show that lead mobilizes from the buckshot residues in distance tissues to the critical organs and interacts with iron, copper, and zinc even though blood lead level sometimes remains unchanged. Our findings are crucial in revealing lead accumulation in critical organs of subjects carrying any gunshot fragments. These subjects and physicians should be in alert for emergence of lead-induced manifestations.

Gap junction channel modulates pulmonary vascular permeability through calcium in acute lung injury: an experimental study

BACKGROUND

Increased pulmonary vascular permeability is a hallmark of acute lung injury (ALI). Gap junction channels (GJCs) connect adjacent cells and facilitate ion exchange. It remained unclear whether GJCs modulate pulmonary permeability in ALI through intracellular calcium.

OBJECTIVES

This study aimed to verify if GJCs in pulmonary microvessel endothelial cells (PMVECs) modulate pulmonary vascular permeability in ALI via intracellular calcium.

METHODS

Firstly, an animal model of ALI was studied using connexin 40 (Cx40) immunohistochemistry in the lung with Evans' blue (EB) leakage. Then cultured PMVECs were divided into three groups: G(control), G(serum) and G(blocker). Serum was obtained from animals with ALI following gunshot injury (injured serum). Initially, G(blocker) was treated with the blocker of GJCs, and then G(serum) and G(blocker) were stimulated with the injured serum, respectively. GJCs, the permeability of cell monolayers and intracellular Ca(2+) were assessed.

RESULTS

Cx40 time-dependently decreased, whereas EB leakage increased. Cx40 and EB leakage exhibited a strong inverse correlation (rho = -0.934, p < 0.05). Injured serum decreased GJCs and expression of Cx40, whereas the blocker aggravated this effect. Similarly, when PMVEC monolayer was treated with injured serum, both permeability and intracellular Ca(2+) increased. These effects were also aggravated with the blocker.

CONCLUSIONS

Depression of GJCs of PMVECs increased pulmonary vascular permeability in ALI; this effect may be mediated by the overload of intracellular calcium.

[The inhibitor of free radical processes decrease of protein biosynthesis in gun short wound tissues and weaken development of the general adaptation syndrome]

The dynamics of total protein biosynthesis and procollagen biosynthesis in skeletal muscle of injury tissues with the antioxidant BHT (dibunol) treatment and with common healing were studied. The obtained date indicate that the AO treatment reduce the rate of biosynthesis both the total proteins and procollagen at the 3th day of healing. Dibunol also considerably reduce the protein biosynthesis in adrenals and brake of corticosteroids biogenesis as measured by ESR-signals intensity of reduced adrenodoxine. AO treatment also reduce the protein biosynthesis in thymus, spleen and bone marrow. The lowering of functional activity of endocrine and immune systems indicate that the AO significantly inhibit the systemic reactions of organism induced by acute wound affect. It was suggested that as "primary mediator" of stress-reaction may be considered lipoperoxide radicals and decay products of lipohydroperoide.

Unusual subcutaneous splenosis occurring in a gunshot wound scar: Pathology and immunohistochemical identification

Splenosis usually occurs after traumatic rupture of the spleen with autotransplantation of splenic tissue to ectopic sites. Most commonly, it occurs as intraperitoneal nodules, which are found either incidentally or after symptomatic complications. Subcutaneous splenosis is a rare condition mostly observed in abdominal surgical scars. Reported herein is a case of subcutaneous splenosis developed in an exit gunshot wound scar on the left lower chest wall 9 years after splenectomy. The lesion presented as an asymptomatic subcutaneous nodule, which was excised under the impression of a skin tumor. Microscopically, there were multiple subcutaneous nodules resembling splenic tissue with red and white pulp. They were confirmed to be ectopic splenic tissue by immunohistochemical staining of the vascular lining cells (CD8+, CD31+, and CD34-). Only 11 cases of subcutaneous splenosis have been reported before. The present case was the third case occurring in an exit gunshot wound scar, and the diagnosis was confirmed by immunohistochemical study.

[Study on changes in inflammatory cytokines and the relationship to multiple organ injury in rats with aspiration lung injury after fire-arm injury]

OBJECTIVE

To observe the phasic variations in concentrations of pro-inflammatory and anti-inflammatory cytokines, and to explore their potential roles in the occurrence and development process of multiple organ dysfunction.

METHODS

Fire-arm induced aspiration lung injury model was replicated. The following parameters were observed: wet/dry weight ratio of rat's lungs, contents of albumin and lactate dehydrogenase (LDH), concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and IL-4 in bronchial alveolar lavage fluid (BALF), contents of alanine amino transferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), serum creatinine (SCr), and MB isoenzyme of creatine kinase (CK-MB).

RESULTS

The wet/dry weight ratio of rat's lungs and contents of albumin and LDH in BALF increased with the passage of time. The concentration of TNF-alpha increased immediately after injury and reached the peak value at 2 hours. The concentration of IL-6 increased obviously 4 hours after injury, and maintained a high level from 4 hours to 24 hours. The concentration of IL-4 decreased from 6 hours to 8 hours after injury. The contents of ALT, AST, BUN, SCr and CK-MB increased continually after injury.

CONCLUSION

Cytokines are the direct mediators for multiple organ failure (MOF), and MOF is triggered by TNF-alpha and a cascade of cytokine release, with a prolonged high-expression of IL-6. The loss of control of IL-4 aggravates the development of MOF.

[Changes of heat-shock protein 70 in the brain of rabbits with craniocerebral missile injury in hot and humid environment]

OBJECTIVE

To study the changes of heat shock protein 70 (HSP70) in the brain of rabbits with craniocerebral missile injury (CMI) and their impact on the injury in a hot and humid environment (HHE).

METHODS

Twenty-four New Zealand white rabbits were randomized into 3 equal groups, namely normal temperature (NT) control group (subjected to treatment at temperature of 22.0+/-0.5 degrees C with relative humidity of 50%), NT gunshot group with CMI and HHE gunshot group with CMI. The rabbits in the latter two groups were subjected to normal temperature of 22.0+/-0.5 degrees C with relative humidity of 50% and environmental temperature of 39.0+/-0.5 degrees C with relative humidity of 80% to 85%, respectively, after establishment of CMI models. HSP70 in the brain tissues and lymphocytes was detected by Western blotting and visualized using chemoluminescence and X-ray films, followed by quantitative gel image analysis.

RESULTS

Expressions of HSP70 in the cortex, hypothalamus and lymphocytes increased apparently in HHE gunshot group, and the changes of HSP70 in the lymphocytes were consistent with those in the cerebral cortex and hypothalamus.

CONCLUSION

HSP70 expression in the brain tissues and the lymphocytes increase evidently after MCI in HHE.

Lead concentrations in ruffed grouse, rock ptarmigan, and willow ptarmigan in Québec

Between 1996 and 1998, ruffed grouse, spruce grouse, willow ptarmigan, and rock ptarmigan harvested by hunters in Québec were examined for lead contamination. On examination of the gizzards of these birds, lead shot was found only in ruffed grouse (1.2%). The probability of ingestion of lead shot by grouse and ptarmigans is low. Analyses of the lead concentrations in the wing bones of grouse and ptarmigans and in the muscle tissue of ptarmigans were conducted. Although differences were observed between individuals based on age and sex, the mean concentrations measured were in the range of those that occur naturally at background levels (<6 microg/g dw). Lead concentrations in muscle tissue were low, often at the limit of detection. However, the few high concentrations detected were probably related to a lead pellet or bullet fragment. Based on an analysis of the health risk associated with consumption of ptarmigan muscle, we conclude that the use of lead ammunition for hunting gallinaceous birds may pose an unnecessary risk of lead poisoning because of the possible ingestion of lead shot, bullets, fragments or embedded shot.

Expression of fibronectin suicidal in gunshot wounds

Fibronectin has been proposed as the reliable marker of wound vitality and potent tool for age estimation in cases where survival time is at least few minutes. Cases of suicidal gunshot wounds were divided into two groups according to projectile energy and damage of the vital structures. Immunohistochemical reaction on fibronectin was evaluated with semiquantitative scale, which included sum of intensity and widespread of the reaction. Mann-Whitney test has shown statistical significant difference between groups (P< or =0.001).

[Morphofunctional characteristics of cell death in the epidermis in gunshot damage to rat skin under experimental conditions]

Different types epidermocyte death were considered in a model of skin gunshot injury in albino rats, Using light microscopy, cytophotometry and immunocytochemistry. Epidermocyte death was characterized by various morphological changes of nuclei, spatial localization of dying cells and different intensity of cellular death, that was registered in all the experimental terms. Cell alterations of necrotic, oncotic and apoptotic types were observed. Oncotic and necrotic type keratinocyte death prevailed in early and middle stages of regenerative histogenesis due to structural and metabolic organic disorders in the skin: in later stages distinctly manifested apoptotic cell death is more possible. However it is more probable that the majority of such cells completes their cycle with necrosis. This is connected to the fact that apoptosis is an energy-dependent process as caspase-activating adapter proteins contact with mitochondrial membranes. Gunshot injury had likely caused definite changes in molecular mechanisms of proliferative processes regulation, cell differentiation and death, leading to accumulation of pathologically altered cells in the epidermis.

[Dynamic changes of SOD and MDA in canine limbs with gunshot wound in hot and humid environment: an experimental study]

OBJECTIVE

To study the dynamic changes in lipid peroxidation and the activity of antioxidative enzyme in canine limbs with gunshot wound in hot and humid environment.

METHODS

Eighteen dogs with gunshot wound were randomly assigned into 3 groups with equal numbers. Dogs observed after injury in normal environment was designated as NE group, those in hot and humid environment as HHE group and those in hot and humid environment with preceding heat acclimatization training as HA group. Contents of superoxide dismutase (SOD) and malonaldehyde (MDA) in both the peripheral blood and muscular tissues from gunshot wound tract were measured at 0, 1, 3, 4, 6, 8, 10, 14, 18 and 24 h respectively after the dogs had been wounded.

RESULTS

Positive correlation between SOD and MDA contents was observed in each group. Three hours after injury, MDA level in HHE group began to ascend, reaching the peak level at 6 h that was significantly higher than those in the other 2 groups (P<0.05); SOD level underwent a reverse change, which was significantly lower in HHE group than in the other groups with that in HA group being the highest. Comparable SOD levels in the groups occurred at the time of 14 h, which happened to MDA levels 4 h later.

CONCLUSION

Gunshot injuries in the limbs of dogs exposed to hot and humid environment induces increased free oxygen and aggravated the lipid peroxidation, which can be alleviated by heat acclimatization.

[Polarographic determination of metals in firearm injuries]

There was tested the use of the polarographic determination of some metals (Pb, Cu, Fe, Sb) in the skin in deceased due to multiple firearm injuries. The authors present on a real case, in which the shots through the dress of victim penetrated, the possibility to determine entry and exit wound.

Similarities between civilian gunshot wounds to the head and nongunshot head injuries

BACKGROUND

This investigation compared the cerebral pathophysiologic status of gunshot wounds to the head (GSWH) with that of severe head injury of other causes (non-GSWH).

METHODS

Data were collected prospectively from 71 GSWH and 541 non-GSWH patients. The two groups had similar demographic characteristics and injury severities. Cerebral metabolic parameters for each patient were averaged for the entire period of monitoring. These per-patient averages were compared between GSWH and non-GSWH groups.

RESULTS

Median intracranial pressure was 21.4 mm Hg in GSWH patients vs. 16.7 mm Hg in non-GSWH patients (p < 0.001). Mean arterial pressures were similar, but the higher intracranial pressure in GSWH patients produced a lower median cerebral perfusion pressure. Cerebral blood flow, cerebrovascular resistance, cerebral metabolic rate of oxygen, average jugular venous oxygen saturation, and number of jugular venous desaturations did not differ significantly between the groups. Three-month outcome was death in 43% of GSWH patients and 32% of non-GSWH patients, persistent vegetative state or severe disability in 33% and 32%, respectively, and moderate disability or good recovery in 24% and 36%, respectively. These outcomes were not significantly different (p = 0.11).

CONCLUSION

GSWH patients suffer global cerebral metabolic disturbances that are at least as severe as those seen in non-GSWH patients with injuries of comparable severity. This selected population of GSWH patients may enjoy outcomes comparable to those of non-GSWH patients if they are treated by the same aggressive protocols.

[The general lipid and lipid peroxidation byproduct content in the erythrocyte membrane among patients with gun shot pulmonary wound]

In the injured persons with gun shot wounds of thorax the lowering of the common lipids lever, high contents of dienic ketones, dienic conjugats and malonic dialdehydes in the blood serum and the erythrocytes membranes before the operation and in postoperative period witness the lipid metabolism and the antioxidant defense system of organism changes.

[Local expresion of proinflammatory cytokines in maxillofacial gunshot wound]

OBJECTIVE

To study the relationship between proinflammentory cytokines and wound healing in local area.

METHODS

Interleukin(IL)-6, IL-8 and tumor necrosis factor-alpha (TNF-alpha) expression in local soft tissues after lower jaw gunshot wound were assessed by using immunohisto-chemistry, and pathological methods.

RESULTS

High expressions of these cytokines were observed in local soft tissues of wounds after the gunshot. The cytokines expressions were different between the area near the bullet path and that far from the path. There was only one peak of the cytokines concentrations in the area far from the bullet path, while there were two peaks of the cytokines concentrations in the area near the bullet path, specially IL-6, IL-8. There were time differences for some different cytokines to reach the peaks of the their concentrations. In wound situ, the fibroblasts, mononuclear phagocytes and endothelial cells expressed IL-6, IL-8 and TNF-alpha after the firearm.

CONCLUSION

These results suggest that proinflammatory cytokines play an important role in regulating inflammatory cytokine reactions of local injury tissues. They might improve the functions of fibroblasts, mononuclear phagocytes and endothelial cells and stimulate wound cells to produce and release other cytokines.

Metabolic changes in the brain during transient ischemia measured with microdialysis

Forty-four patients with severe head injury were monitored for episodes of cerebral ischemia using jugular venous oxygen saturation (sjvO2), brain tissue pO2 (ti-pO2), and a microdialysis probe. The concentration of lactate and glucose were measured in the microdialysate. A total of 10 episodes of global ischemia were observed. The characteristic pattern of a simultaneous decrease in sjvO2 and brain ti-pO2 with an increase in the concentration of lactate occurred in all 10 patients. In addition, 3 episodes of regional ischemia were observed. Although brain ti-pO2 decreased to very low values and the concentration of lactate increased in the microdialysate, sjvO2 remained unchanged. Brain ti-pO2 adds another dimension to our cerebral monitoring by allowing the detection of regional cerebral ischemia.

Change in substance P in a firearm wound and its significance

The present study was designed to detect the change of substance P (SP) in firearm wounds and its relationship with wound healing. Twenty two rabbits were randomly divided into two groups, one with firearm wounds created by steel balls shooting rabbits' thighs and another with stab wounds created by knife. The experimental design did not include direct injury to femora major peripheral nerve trunks or blood vessels. SP content in wound tissue of both groups was measured with radioimmunoassay (RIA). Histologic examination was performed on the wound and the saphenous and sciatic nerves away from the wound-track edges. It was found that both types of injuries caused an increase of SP content in the wound compared with normal tissue. At three to 10 days after injury, SP content was lower in firearm wounds than that in stab wounds. Pathomorphologic observation showed the indirect injuries to the saphenous and sciatic nerves in the rabbits with firearm wounds were more severe than those with stab wounds. Meanwhile, wound healing in the firearm wounds was poor compared with that in the stab wounds. The results suggest that the change in SP in firearm wounds differs from that in cold weapon wounds as a result of the presence of indirect injuries to major peripheral nerve trunks created by laceration shock wave and cavity effects, and SP in vivo may participate in wound healing as a growth factor. Therefore, the improvement of neuropeptide metabolism in firearm wound may be an important measure for accelerating wound healing.

Pediatric craniocerebral wounds from plastic bullets: prognostic implications, course, and outcome

OBJECTIVE

To review our experience with craniocerebral injuries caused by plastic bullets, and to delineate prognostic factors for outcome.

DESIGN

Retrospective case series of 29 patients presenting with plastic bullet-induced craniocerebral lesions.

SETTING

Pediatric intensive care department of a tertiary care center.

MEASUREMENTS AND MAIN RESULTS

Outcome was poor in 10 patients, good in 11, and two and six patients were moderately and severely disabled, respectively. Statistical analysis showed prognostic significance of the admission Glasgow Coma Scale score, computed tomographic findings of intraventricular hemorrhage and midline shift, and metabolic studies including hypokalemia and hyperglycemia.

CONCLUSIONS

Plastic bullet-induced craniocerebral injuries carry a lower morbidity and mortality rate compared with other gunshot wounds. However, plastic bullets do incur a significant risk of injury. Their use should be carefully regulated.

Glut1 glucose transporter activity in human brain injury

The principal glucose transporter at the blood-brain barrier (BBB) is the Glut1 isoform, and transporter density is believed to be an index of cerebral metabolic rate. In the present study, glucose transporter expression was studied in tissue resected 7-8 h after acute traumatic brain injuries in 2 patients. Light microscopic immunochemistry indicated a zone of complete loss of the Glut1 glucose transporter isoform in microvessel endothelial cells adjacent to sites of small vessel injury, concentrically surrounded by a narrow zone of variable Glut1, and distally surrounded by capillaries with typically immunoreactive endothelia in nondisrupted parenchyma. Variably reactive capillaries displayed alternating sectors of greatly reduced and highly reactive Glut1 density, suggesting a high density and low density of transporter activity in contiguous endothelial cells. Quantitative electron microscopic immunogold analyses demonstrated that the transporter was predominantly localized to the luminal and abluminal endothelial membranes, with lesser reactivity in cytoplasm; pericyte Glut1 was minimally above background levels. In endothelial sectors with reduced Glut1 transporter immunoreactivity, the luminal:abluminal ratio of Glut1 epitòpes was less than unity; while it is greater than unity in highly reactive endothelial cells. The number of Glut1-immunoreactive sites per micrometer of capillary membrane was not significantly different from previous reported Glut1 density in seizure resections, and about 2- to 3-fold higher than in human red cells. In the same tissue samples, qualitative immunogold electron microscopy of human serum albumin indicated leakage of this protein (MW 65,000) from the vascular space into pericapillary regions. Thus the high Glut1 density observed in capillaries from acutely injured brain occurs concomitantly with compromised barrier function.

A prospective randomized study of end points of resuscitation after major trauma: global oxygen transport indices versus organ-specific gastric mucosal pH

BACKGROUND

Gastric tonometry, as a method of organ-specific monitoring of the status of the splanchnic circulation, has demonstrated prognostic and therapeutic implications in critically ill patients. The experience with this method in patients with trauma has been limited.

STUDY DESIGN

Fifty-seven patients were prospectively randomized into two groups: group 1, n = 30, normalization and maintenance of gastric mucosal pH (pHi) at or above 7.3 and group 2, n = 27, maintenance of oxygen delivery index of 600 or an oxygen consumption index of greater than 150. The groups had statistically similar injury severity scores, lactate levels, and base deficits.

RESULTS

Of the 44 patients with pHi greater than 7.3 at 24 hours, three (6.8 percent) died of multiple organ dysfunction syndrome as compared with seven (53.9 percent) of 13 in whom pHi was not optimized, p = 0.006. Optimization times for oxygen delivery index, oxygen consumption index, lactate levels, and base excess were similar between survivors and nonsurvivors. The time for pHi optimization was significantly longer in nonsurvivors. Multiple organ dysfunction syndrome points were significantly higher in patients who did not have pHi optimized within 24 hours (6.08 compared with 2.5, p = 0.03). Optimization time for pHi was predictive of mortality on multiple regression. Persistently low pHi was frequently associated with systemic or intra-abdominal complications. It was the first finding in all the nonsurvivors at least 48 to 72 hours before death.

CONCLUSIONS

Gastric mucosal pH may be an important marker to assess the adequacy of resuscitation. Monitoring of pHi may provide early warning for systemic complications in the postresuscitation period.

Cerebral extraction of oxygen, lactate production, and perfusion pressure in gunshot wound to the head: case report

A case of gunshot wound to the head is presented, in which the patient made a satisfactory recovery after a prolonged period of elevated intracranial pressure and increased cerebral extraction of oxygen. Even though cerebral extraction of oxygen was increased in the most acute phase, the arteriojugular lactate difference was never abnormally decreased (ischemic). This finding indicated that, in this patient, increased cerebral extraction of oxygen was not sufficient to result in global cerebral ischemia (increased cerebral lactate production). To our knowledge, this is the first report on frequent serial assessment of cerebral extraction of oxygen and lactate production in severe penetrating head injury.

The effect of indirect injury to peripheral nerves on wound healing after firearm wounds

This paper reports the pathologic and functional changes of the sciatic nerve indirectly injured by firearms and its effect on wound healing. Twelve dogs were used. Their hind legs were shot with 1.03-gram steel spheres, avoiding direct injury to the sciatic nerve. The experimental animals were divided into two groups according to the impact velocity, that is, a 1,500 m/sec high velocity projectile (HVP) group and a 400 m/sec, low velocity projectile (LVP) group as a control. After wounding, the same procedure was followed in all dogs. At intervals, the tissues of the wound track were excised to determine the level of cyclic nucleotides (cAMP, cGMP), secondary messengers of neurotransmitters, the activity of acetylcholinesterase (AChE), and the content of hydroxyproline, which indicates the degree of wound healing. The sciatic nerve next to the wound track was excised for light and electron microscopic study. The neurofilament in the sciatic nerve was examined by immunohistochemistry with monoclonal neurofilament-200 antibody. The results showed that the indirect injuries to the sciatic nerves of the HVP group were more severe than in those in the LVP group and included naked axons, stripped myelin sheaths, widened nodes of Ranvier, and decrease in the numbers of neurofilaments. At 6 hours, cAMP content in the HVP group was significantly lower than that in the LVP group. It began to rise and approached to the level of LVP group at 10 days. The cGMP content, activity of AChE, and hydroxyproline content of the HVP group were significantly lower than those of the LVP group. The results suggested that the indirect injury to sciatic nerves, especially to the cytoskeleton, after HVP wounds may induce the disturbance of an axoplasmic flow and influence the metabolism of trophic factors such as cAMP, cGMP, and AChE. All changes could contribute to the delay in wound healing.

[Immunohistochemical study of 5-HT on gunshot wound of human skin]

Fourty antemortem and 30 postmortem gunshot wound samples of human skin were studied by immunohistochemical method. The 5-HT was seen mainly in wound edge, papillary layer, hypodermis and surrounding tissue of all antemortem gunshot wounds. The 5-HT was also discovered on the postmortem gunshot wounds which occurred within 8 minutes after death. The result showed that immunohistochemical staining of 5-HT be useful for diagnosing the antemortem gunshot wound. It also demonstrated that the mast cells of human do not contain 5-HT. We also studied the rate of mast cell degranulation of gunshot wounds of human skin by toluidine blue staining. The rate of mast cell degranulation of antemortem gunshot wounds increased (50%), and it was higher than that of postmortem gunshot wounds, suggesting that the rising of degranulation rate is a sign of antemortem injury.

Multiple organ injuries after abdominal high energy wounding in animals and the protective effect of antioxidants

Multiple organ injuries caused by high energy abdominal wounds were studied in 8 pigs and 24 dogs, and at the same time the protective effect of antioxidants in 14 dogs with multiple organ injuries was also studied. The experimental results showed that: 1) more than two organs (six organs at most) were wounded in each of the animals studied; 2) the injuries were characterized by hemorrhaging, tissue rupture and hematoma, and the main pathologic changes were local edema and necrosis; 3) the marked increase of lipid peroxide (LPO) levels in the vital organs indicated that multiple organ injuries could also involve the molecular level; 4) the injuries were due to the direct effect of pressure waves and ischemic reperfusion and not to shock or infection; and 5) antioxidants (vitamin E and Salvia miltiorrhiza Bge.) exhibited significant protective effects against multiple organ injuries through a free radical mechanism.

[THe results of a study of combat surgical pathology]

The basis of this report is composed of summarized studies which were conducted by the Combat Surgical Trauma Research Institute. From 1983 the research workers of this Institute were visiting medical units of the 40th Army, and from February, 1987 research groups were working at the Central Military Hospital and one of the separate medical battalions which was equipped with special medical facilities.

[An experimental study of pathomorphologic characteristics and changes in energy metabolism of wound track on maxillofacial region of dogs]

The maxillofacial soft tissue wounds of dogs were inflicted by the spherical steel bullet with primary velocity 1.3 km/sec, 0.7 gm in weight. The pathomorphologic characteristics at 0-0.8, 0.8-1.6 and 1.6-2.4 cm from the wounding tracts were observed with light microscopy, and the amount of high energy phosphates (ATP) in the muscle samples was determined. The experimental results indicated that the contusion zone of skin and mucous membrane was 0.1-0.2 cm. and that of muscle was 0.5-0.8 cm the easily debridement is useful for the recovery of metabolism function. As they were wounded by the same velocity missiles, the soft tissue contusion zone of maxillofacial region was smaller than that of extremities.

Pressure waves caused by high-energy missiles impair respiration of cultured dorsal root ganglion cells

High-energy missile extremity impact causes short-lasting pressure waves which traverse the body with a velocity close to that of sound in water. In order to elucidate mechanisms for distant damage in a living body to the peripheral and central nervous system, a model system was designed aimed to create pressure waves with amplitudes, frequency spectrum, and duration fairly comparable to those recorded in situ. Our model system enabled exposure of tissue cultures of dorsal root ganglion (DRG) and endothelial cells under strictly controlled conditions to a burst of oscillating pressure waves and to determine possible influence on oxygen consumption. Oscillating pressure waves caused by high-energy missile impact (velocity 1,200 m/s) reduced the oxygen consumption by more than 80%. However, in spite of this drastic, acute effect the ganglion cells and the feeder layer cells did not reveal any immediate plasma membrane dysfunctions as revealed by cytoplasmic uptake of Evans blue protein marker complexes. It is concluded that pressure waves fairly similar to those demonstrable in vivo in the vicinity of the peripheral and central nervous system after high-energy missile extremity impact in pigs reduce the respiration of DRG cells and endothelial cells in culture. The mitochondrial impairment is not associated with concomitant plasma membrane dysfunction for macromolecules. Nerve cells seem to be more vulnerable than the other type of cultured cells examined.

Comparison of gunshot wounds and field-tipped arrow wounds using morphological criteria and chemical spot tests

Arrow wounds represent an unusual class of wounds rarely seen by most death investigators. Although the edged, broadhead-tipped arrow produces a wound usually characteristic of archery/crossbow weapons, the plain, field-tipped arrow wound can be confused with gunshot injuries in those cases in which powder residue or firearm projectiles or fragments or both are not recovered. We present a case of a deer carcass with a wound of uncertain firearm or archery origin which initiated a comparison of firearm wounds and archery wounds on fresh road-killed deer. We found the following features to be valuable in the differentiation of gunshot wounds and field-tipped archery wounds: First, the majority of the gunshot wounds (but none of the arrow wounds) had identifiable, macroscopic, wipe-off material and chemically identifiable wipe-off residue by spot test. Second, the archery wound defects had very inconspicuous abrasion rings as compared to the often prominent abrasion rings of gunshot wounds. Third, the actual central defect in the archery wounds was more likely to be oblong or slit-like compared to the gunshot wound defects, which were more likely to be round.

Lead poisoning from retained missiles. An experimental study

The problem of lead poisoning from bullets has been investigated by surgically implanting discs of lead, each enriched in a different natural isotope, into the tissue of two mongrel dogs and monitoring by mass spectrometry the release of the lead into each animal's blood over the course of 3 years. Lead placed in the knee underwent vigorous attack by the synovial fluid, far in excess of what would be expected from corrosion theory, and reached a maximum concentration in blood 4-6 months after operation. Thereafter, lead concentration exponentially declined as the remaining fragments became encapsulated. The disc placed in muscle was sparingly soluble immediately following implantation. It is concluded that the greatest danger of lead poisoning from an injury involving many fragments having collectively a large surface area will occur within a month, and that the cases of lead poisoning resulting from bullets in joints that occur 5 or more years after injury are caused by continual wear of metal on a joint surface, storage of lead so released in the skeleton, and its subsequent resorption during a change in osteocyte activity.

[The other face of oxygen (2)]

The authors, in this second part of "The other face of Oxygen", pay attention no more to O2, the "untrustworthy" protagonist of oxidation, but to the opposite side, namely the "physiologic" antioxidative protections. Such antioxidative protections, which were being prepared and improved in cell, in interstices and in organic liquids, during millions of pears, perhaps represent the "most true" witness of the always "traumatic" cohabitation between organisms, although eukaryote, and oxygen. This, after all, in spite of the evolutive push, remained an element "foreign" to life, although, paradoxically, first protagonist of it. Similarly, "singularly foreign" appear mitochondria, namely the forges specifically entrusted with the respiratory metabolism.

Local skeletal muscle surface oxygen pressure fields after high-energy trauma

In the assessment of viability of traumatized muscle tissue clinical signs, including colour, consistency, capillary bleeding and contractility have been commonly used. One of these signs, discolouration, has been shown in earlier studies to be associated with impaired circulation and severe and irreversible changes of muscle electrolytes and energy metabolism. In this study the circulation and tissue oxygen pressure fields were studied on either side of the "demarcation line" between discoloured and normally coloured areas of traumatized muscle tissue. Anaesthetized pigs were injured in one thigh with a high velocity spherical steel missile. The microcirculatory flow of the traumatized muscle was studied by measuring the clearance of 133Xenon from the surface of the muscle and tissue oxygen pressure (PtO2) was measured with an MDO electrode. Measurements were done before and 1, 3 and 5 hours after the trauma. A markedly decreased or absent flow as well as very low PtO2 values were found within areas of discolouration. In the adjacent normally coloured areas no such changes were noted and the values of these areas resembled those of the contralateral untraumatized leg. The results agree with those of earlier studies of circulation and metabolic changes indicating that discolouration is a useful sign in the clinical assessment of muscle viability after high-energy trauma.

Effects of penicillin G on local metabolic changes in skeletal muscle following high velocity missile injury

The effect of systemic penicillin G treatment on the local tissue damage 12 h after a high velocity missile injury in skeletal muscle has been studied in pigs (n = 13). Blood pressure, rectal temperature, hemoglobin concentrations, hematocrits, blood gases and acid base balances were followed and the tissue levels of ATP, creatine phosphate, glucose-6-phosphate, glucose and lactate were determined in control skeletal muscle as well as in muscle samples taken from the wound area. After 12 h all devitalized tissue was debrided and weighed. Penicillin G treatment slightly diminished the local tissue metabolic deterioration and significantly reduced the amount of debrided tissue as compared to untreated animals. It may be concluded that early treatment with penicillin G will considerably diminish the local tissue damage during the first 12-hour period following a high velocity missile injury.

Local metabolic changes in skeletal muscle following high-energy missile injury

The extent of cellular deterioration around a high-velocity missile injury was studied in canine skeletal muscle biopsies. The tissue levels of high-energy phosphates and glycolytic metabolites were analyzed in four zones surrounding the bullet tract and in an uninjured extremity. Incorporation of leucine into skeletal muscle proteins in vitro in the different zones was determined. In the tissue adjacent to the bullet tract ATP and phosphocreatine (CP) decreased significantly and remained low. No significant changes of ATP and/or CP occurred in the other zones or in the control muscle. Lactate and glucose levels increased in all zones but G6-P levels decreased in the three zones close to the wound indicating anaerobiosis and disturbed utilization of glucose. Incorporation of leucine decreased in the innermost zone and no restoration took place, but more peripherally a certain reversible decrease was seen. The present results indicate that irreversible cell damage will occur in the tissue adjacent to a high-velocity bullet tract. Reversible cellular dysfunction may occur in tissues without gross changes.

Insulin half-life in man after trauma

To explore the possibility that the half-life of insulin changes after trauma, five control subjects and 19 severe trauma patients received intravenous glucose (0.5 gm/kg) in 5 minutes to raise rapidly the insulin levels, followed immediately by 300 mg of intravenous diazoxide over 5 minutes to inhibit any further insulin secretion. Serial blood samples were analyzed for immunoreactive insulin, and insulin half-life was calculated. The baseline insulin level was 13.4 +/- 3.8 microU/ml in the trauma group 10.4 +/- 3.1 microU/ml in the control group. During the glucose infusion, insulin levels rose to 177.0 +/- 56.0 microU/ml in the controls and to 127.0 +/- 27.0 microU/ml in the trauma group. The rise in the control subjects was greater (P less than 0.03) than the rise in the trauma patients. After diazoxide, insulin levels fell to 25.0 +/- 6.2 microU/ml and 25.0 +/- 6.6 microU/ml, respectively. Insulin half-life in the control subjects was 5.2 +/- 0.3 min and 3.9 +/- 0.2 min in the trauma group (P less than 0.019).

The absence of protein--sparing effects utilizing crystalline amino acids in stressed patients

The protein-sparing effects of the peripheral infusion of crystalline amino acids (PAA) was studied metabolically in selected surgical patients subjected to various degrees of stress. Twenty-one patients (sixteen cancer patients receiving chemotherapy and/or radiotherapy, three with major abdominal traumatic injuries and four with paralytic ileus) were infused with 2 1/24 hours of a solution of 4.2% Travasol amino acids with only 5% glucose as a source of nonprotein calories. One-half of the cancer patients were also allowed ad libitum oral intake of a regular hospital diet or Vivonex-HN. The nutritional status was evaluated by measuring changes in body weight, serum albumin levels and nitrogen balance. Body weight decreased in only the trauma patients. When these solutions were the sole source of nutrients all patients were in negative nitrogen balance and had significant decreases in their serum albumin levels. Serum albumin levels were preserved only when extra sources of calories were provided. The infusion of the crystalline amino acids without adequate levels of nonprotein energy did not conserve protein in these stressed patients.

Detailed monitoring of the effects of mannitol following experimental head injury

The experimental model of a cerebral missile injury developed by Crockard was used in three groups of Rhesus monkeys treated with mannitol. One group received mannitol 15 minutes after being injured with a BB pellet at 90 m/sec impact. Another group was wounded identically, but mannitol treatment was delayed until 1 hour after injury. The last group was wounded with the missile traveling at 180 m/sec, and mannitol was started 15 minutes after trauma. The data were contrasted with the results from the original model. After receiving mannitol, all groups showed marked improvement in mean blood pressure, cerebral perfusion pressure, cerebral blood flow, and cerebral metabolic rate of oxygen consumption out of proportion to the degree of reduction in intracranial pressure (ICP). The authors conclude that the therapeutic value of mannitol may, in some injuries, be directly related to its effects on blood flow and metabolism, as well as to its better known effects upon ICP.