Effect of Erysod (erythrocyte superoxide dismutase) on blood concentration of reactive oxygen species in patients with severe burns and burn shock

The dynamics of blood concentrations of reactive oxygen species and LPO products in patients with thermal injuries of different severity was studied. Monitoring of these parameters by chemiluminescent and spectrophotometric techniques helps to predict the course of burn shock and prevent complications. Erysod (0.004% solution, 33-66 g/min, daily dose 24-32 mg) added to antishock infusion therapy during the early periods after injury suppressed generation of free radicals (by 20% after 15 min and by 30-40% after 24 h), promoted normalization of their contents, and reduced damage to visceral organs during acute period of thermal injury.     

A randomized trial to compare 24 h versus 12 h double dose regimen of levonorgestrel for emergency contraception

BACKGROUND: Levonorgestrel (0.75 mg given for two doses 12 h apart) has been proven to be an effective regimen for emergency contraception when the first dose is given within 72 h of unprotected coitus. However, the dosing interval is inconvenient for those taking the first dose in the afternoon. We conducted a randomized study to evaluate two levonorgestrel dosing regimens for emergency contraception. Two doses of levonorgestrel 0.75 mg were administered with the first dose given up to 120 h after unprotected intercourse. The second dose was given 12 h later in the first regimen and 24 h later in the second regimen. METHODS: We conducted a double-blind, randomized trial between 1997 and 2003 at five centres in China. A total of 2071 women requesting emergency contraception within 120 h of unprotected intercourse were recruited. They were randomized to receive two doses of 0.75 mg of levonorgestrel, given either 24 h apart or 12 h apart. RESULTS: Outcome was unknown for 53 women (24 in the 24 h group and 29 in the 12 h group). Among the remaining 2018 women, the crude pregnancy rate was 1.9% in the 24 h group [95% confidence interval (CI) 1.17-2.94] and 2.0% in the 12 h group (95% CI 1.19-2.99). The proportion of pregnancies prevented was estimated to be 72% in the 24 h group and 75% in the 12 h group. Side-effects were mild in both groups. The efficacy of the 12 h regimen declined significantly when there were further acts of intercourse after treatment (5.0 versus 1.0%, P<0.01). This was not observed in the 24 h group. CONCLUSIONS: Two doses of 0.75 mg levonorgestrel given either 24 or 12 h apart are effective for emergency contraception up to 120 h after unprotected intercourse. Further research to investigative more effective methods of emergency contraception is warranted.     

Time course of inflammation, oxidative stress and tissue damage induced by hyperoxia in mouse lungs

In this study our aim was to investigate the time courses of inflammation, oxidative stress and tissue damage after hyperoxia in the mouse lung. Groups of BALB/c mice were exposed to 100% oxygen in a chamber for 12, 24 or 48 h. The controls were subjected to normoxia. The results showed that IL-6 increased progressively after 12 (P < 0.001) and 24 h (P < 0.001) of hyperoxia with a reduction at 48 h (P < 0.01), whereas TNF-α increased after 24 (P < 0.001) and 48 h (P < 0.001). The number of macrophages increased after 24 h (P < 0.001), whereas the number of neutrophils increased after 24 h (P < 0.01) and 48 h (P < 0.001). Superoxide dismutase activity decreased in all groups exposed to hyperoxia (P < 0.01). Catalase activity increased only at 48 h (P < 0.001). The reduced glutathione/oxidized glutathione ratio decreased after 12 h (P < 0.01) and 24 h (P < 0.05). Histological evidence of lung injury was observed at 24 and 48 h. This study shows that hyperoxia initially causes an inflammatory response at 12 h, resulting in inflammation associated with the oxidative response at 24 h and culminating in histological damage at 48 h. Knowledge of the time course of inflammation and oxidative stress prior to histological evidence of acute lung injury can improve the safety of oxygen therapy in patients.     

Role of biphasic changes in splenic dendritic cell activity in a mouse model of multiple organ dysfunction syndrome

To analyze the changes in splenic dendritic cell (DC) activity and serum cytokine levels during the progression of multiple organ dysfunction syndrome (MODS). A C57BL/6 mouse model of MODS was established by intraperitoneal injection of zymosan. Immunohistochemistry and flow cytometry were used to detect expression of I-A^b (MHC-II molecules of mice) as well as co-stimulatory and co-inhibitory molecules in spleen and DC surface. The levels of various cytokines in serum and spleen tissue were analyzed 6 h, 12 h, 24 h, 48 h, 5 d and 12 d after injury. Death occurred at 24-48 h and 10-12 d after injury. The expression of I-A^b and CD86 in spleen tissue and on DCs increased 6-12 h after injury, followed by gradual reduction and at 12 d. The inhibitory molecule, PD-L1, was expressed on normal DCs, but expression of PD-1 was undetectable. PD-L1 and PD-1 expression increased and remained high at 5 d and 12 d after injury. In addition, TNF and IL-1 levels increased 6-12 h after injury; HMGB1 and IL-10 levels increased 24 h and 5 d after injury, respectively. In contrast, IL-2 and IL-12 decreased with disease progression. At 12 d after injury, proinflammatory and anti-inflammatory cytokine levels remained high, while IL-2 and IL-12 were significantly reduced. IL-10 and IL-12 changes in spleen were consistent with those in serum. MODS progression was characterized by changes in splenic DC activity as well as altered serum pro-inflammatory and anti-inflammatory cytokine levels, suggesting early immune activation and predominant immune tolerance at the late stage.     

Post-ischemic delivery of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor rosuvastatin protects against focal cerebral ischemia in mice via inhibition of extracellular-regulated kinase-1/-2

After recent clinical trials, statins have gained increasing significance in secondary stroke prevention. From experimental studies, it is well established that statins have beneficial action when delivered prophylactically prior to a stroke. Conversely, much less is known about the effects of statins on injury development when delivered after ischemia. We here examined the effects of a post-ischemic delivery of rosuvastatin (0.5, 5 or 20 mg/kg, administered i.p. immediately after reperfusion onset), a potent 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on brain injury and cell signaling after focal cerebral ischemia, induced by 90 min of intraluminal middle cerebral artery occlusion in mice. In animals receiving normal saline, 0.5 or 5 mg/kg rosuvastatin, middle cerebral artery occlusions resulted in reproducible brain infarcts at 24 h after reperfusion onset, which did not differ in size. However, rosuvastatin, administered at higher doses (20 mg/kg), reduced infarct volume at 24 and 48 h after ischemia (by 34+/-16% and 18+/-3%, respectively, P<0.05). Western blots revealed that rosuvastatin decreased phosphorylated extracellular-regulated kinase-1/-2 and reduced activated caspase-3 levels in ischemic brain areas, while endothelial NO synthase expression, p38 and Jun kinase phosphorylation were not influenced by the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. Rosuvastatin also significantly diminished expression levels of inducible NO synthase in the ischemic brain. Our results indicate that rosuvastatin may have utility not only as stroke prophylaxis but also as acute therapy inhibiting executive cell death pathways.     

Neuroendocrine-immune interactions associated with loss and restoration of immune system function in spinal cord injury and stroke patients

Both natural and adaptive immune responses were shown to be strikingly decreased in initial blood samples from 34 spinal cord injury and stroke patients. NK-cell function decreased to 24.8% (mean) 2 weeks after spinal cord injury in previously healthy young adults whose control group revealed a mean NK-cell function of 48.7%. This was accompanied at 2 weeks by increased plasma ACTH (mean of 17.0 pg/ml from 17 patients compared to a mean of 11.2 pg/ml from 12 controls) and urine free cortisol levels (mean of 152.1 micrograms/24 h from 9 patients compared to 53.6 micrograms/24 h from 15 controls). T-cell function and/or activation decreased to below normal values within 3 months after injury as revealed by lymphocyte transformation that was 32.8% of normal at 3 months. T-cell activation diminished as shown by a mean IL-2 receptor level of 179.3 units/ml in patients compared to 328.2 units/ml in controls. Serial monitoring of NK- and T-cell function revealed that specific physical rehabilitation therapy over a period of 6 months after injury restored NK- and T-cell function to near normal levels in most patients. This improvement was accompanied by a parallel rise in the patient's functional independence measurement scores. Results suggest critical neuroendocrine-immune system interactions in the restoration of immune function. Cortisol levels reverted to normal after 6 months of rehabilitation. Limited data suggest that natural immune system depression, NK-cell function, persists in spinal cord injury patients not receiving rehabilitation therapy (mean NK-cell lysis of 10.3%; p < 0.01).     

Injury and repair of the soleus muscle after electrical stimulation of the sciatic nerve in the rat.

To study injury and subsequent changes in skeletal muscles, the rat sciatic nerve was electrically stimulated at 50 Hz and muscle contraction was induced for 30 min. Muscle damage was classified into five types (hypercontraction, hyperstretching, Z band disorders, misalignment of myofilament and regions of scarce myofilaments) by electron microscopy and quantified by ultrastructural assessment. After electrical nerve stimulation, the percentages of the injured areas of the soleus muscle were 18.8 +/- 15.8% (mean +/- SD) at 0 h, 9.7 +/- 1.0% at 6 h, 22.0 +/- 23.6% at 12 h, 13.1 +/- 3.2% at 24 h, 4.9 +/- 6.0% at 3 days and 0.5 +/- 0.4% at 7 days. At 0 h, the vast majority of ultrastructural alterations were sarcomere hypercontraction. At 6 h, hypercontraction was not recognizable and sarcomere hyperstretching and Z band disarrangement constituted the major findings. At 12 h, when the injury reached its maximum, myofilament disorganization and hyperstretching were predominant. At 24 h or afterwards, the injury began to decrease and recovered to almost normal conditions by 7 days. There were very few necrotic muscle fibers in all specimens. It is considered that the muscle lesions in the present study were reversible, and recovered through changes in various types of sarcomere alterations. Z band streaming and free ribosomes were frequently found at 12 and 24 h, which may indicate repair processes rather than newly formed lesions.     

高血压项目临床检测样本保存和稳定性标准化研究

目的 探讨不同保存温度和时间条件下高血压五项检测血浆样本的稳定性.方法 收集20例Renin、ALD、ACTH、Cortisol水平不同的受试者样本,分别保存在不同温度(常温、4℃、-20℃、-80℃)和不同时间(24h和48h),另外20例AII水平不同的受试者样本,分别在不同时间(即时、2h、4h、8h、12h、24h)添加酶抑制剂,并在不同温度和时间(常温下2h、4h、6h、8h,4℃下4h、8h、12h、24h,-20℃下12h、24h、48h、72h)下保存,计算偏倚.结果 在室温保存条件下,Renin浓度在24h内降低9%,而4℃条件下保存,24h内升高14%,在-80℃保持稳定.ACTH浓度在室温保存下降低32%,-20℃和-80℃条件下保存比较稳定.ALD和Cortisol浓度受保存温度及时间变化影响较小,48h内变幅在5%以内.AII在采血后的不同时间段添加酶抑制剂,8h后升幅超过10%;样本采集后立即添加酶抑制剂,在常温保存8h条件下及4℃下保存24h后均减少超过50%,而在-20℃条件下48h降幅在10%以内.结论 Renin和ACTH需在-20℃以下的低温保存,ALD和Cortisol对温度没有要求,AII需立即加入酶抑制剂并尽快检测,如果不能尽快检测,需分离血浆后保存在-20℃条件下,并在48h之内完成检测.本研究为临床检验制定完善的高血压五项样本保存条件提供了依据.     

Involvement of caspase-1 proteases in hypoxic brain injury. effects of their inhibitors in developing neurons

To further explore the contribution of caspase-1/interleukin-1beta-convening enzyme in the consequences of hypoxia in developing brain neurons, its temporal expression profile was analysed by immunohistochemistry and western blotting in cultured neurons from the embryonic rat forebrain subjected to a hypoxic stress (95% N2/5% CO2 for 6 h), and proteolytic activity of caspase-1 was monitored as a function of time by measuring the degradation of a selective colorimetric substrate (N-acetyl-Tyr-Val-Ala-Asp-p-nitroanilide). In addition, the influence of pre- and posthypoxic treatments by caspase-1 inhibitors (N-acetyl-Tyr-Val-Ala-Asp-aldehyde and N-acetyl-Tyr-Val-Ala-Asp-chloromethylketone) was tested on cell outcome. Hypoxia led to delayed apoptotic neuronal death, with an elevation of the expression of both pro-caspase-1 and caspase-1 active cleavage product (ICE p20) for up to 96 h after cell reoxygenation. As reflected by cleavage of the specific substrate, caspase-1 activity progressively increased between 24 h and 96 h posthypoxia, and was blocked by inhibitors in a dose-dependent fashion. The inhibitory compounds, including when given 24 h after hypoxia, prevented neuronal death, reduced apoptosis hallmarks and also increased the number of mitotic neurons, suggesting they might promote neurogenesis. Similar observations were made when neurons were exposed to a sublethal hypoxia (i.e. 3 h). These data emphasize the participation of caspase-1 in neuronal injury consecutive to oxygen deprivation, and provide new insight into the possible cellular mechanisms by which caspase inhibitors may protect developing brain neurons.     

Peri-sciatic administration of indomethacin early after nerve injury can attenuate the development of tactile allodynia in a rat model of L5 single spinal nerve injury

To clarify the role of cyclooxygenase in the peripheral nerve on the development of neuropathic pain, we investigated the effects of peri-sciatic administration of indomethacin on the development of allodynia in a model of L5 single spinal nerve injury. Peri-sciatic administration of indomethacin (1 mg/kg) was performed 3, 24, or 72 h after nerve injury (n=6/each). In rats with indomethacin 3 or 24 h after nerve injury, ipsi-lateral paw withdrawal thresholds 7-35 days after nerve injury were significantly higher compared with those in the control group (n=6: without peri-sciatic treatment) (P<0.05). However, such efficacy was no longer apparent when indomethacin was administered 72 h after nerve injury. These results suggest that peri-sciatic administration of indomethacin early (less than 24 h) after nerve injury can attenuate the development of allodynia.     

Effect of post-hypoxic reoxygenation on DNA fragmentation in cortical neuronal nuclei of newborn piglets

Previous studies have shown an increased fragmentation of genomic DNA following hypoxia in cortical neuronal nuclei of newborn piglets. The present study tests the hypothesis that DNA fragmentation following hypoxia persists during reoxygenation in cortical neuronal nuclei of newborn piglets. To test this hypothesis, DNA fragmentation was assessed in 36 newborn piglets divided into six groups: normoxic (Nx), hypoxic (Hx) and hypoxic/reoxygenated for 6, 12, 24h and 7 days. The Hx groups were exposed to 7% oxygen for 1h followed by reoxygenation to room air for 6, 12, 24h and 7 days. Cerebral tissue hypoxia was confirmed biochemically by ATP and phosphocreatine (PCr) levels. Nuclei were isolated and purified using discontinuous sucrose gradient. DNA was isolated by phenol/chloroform/isoamyl-alcohol extraction method. ATP/PCr (micromol/g brain) were 4.11+/-0.15/3.67+/-0.30 for Nx, 1.31+/-0.68/0.74+/-0.30 for Hx, 3.81+/-0.11/3.24+/-0.14 for 6h reoxygenation, 4.21+/-0.12/3.27+/-0.09 for 12h reoxygenation and 4.63+/-0.09/3.75+/-0.27 for 24h reoxygenation and 4.31+/-0.12/3.70+/-0.21 for 7 days reoxygenation. There was a significant difference in the ATP and PCr values between Nx and Hx groups (p<0.05) and between Hx and hypoxic reoxygenated groups (p<0.05). DNA fragments (OD/mm(2)) increased from 1776+/-267 in the Nx group to 3211+/-285 in the Hx group (p<0.05). In the reoxygenation groups, DNA fragments (OD/mm(2)) decreased to 2018+/-249 after 6h (p<0.05 versus Hx) but increased to 3408+/-206, 2782+/-406 and 3256+/-302 after 12, 24h and 7 days, respectively. The data show a decrease in DNA fragmentation in the early phase (6h) of reoxygenation but is comparable to acute hypoxia during the later phases (12, 24h and 7 days) of reoxygenation. We propose that the biphasic pattern of DNA fragmentation during reoxygenation occurs by an initial oxidative DNA injury followed by an enzymatic cleavage of DNA by endonucleases activation.     

The mitochondrial permeability transition, and oxidative and nitrosative stress in the mechanism of copper toxicity in cultured neurons and astrocytes

Copper is an essential element and an integral component of various enzymes. However, excess copper is neurotoxic and has been implicated in the pathogenesis of Wilson's disease, Alzheimer's disease, prion conditions, and other disorders. Although mechanisms of copper neurotoxicity are not fully understood, copper is known to cause oxidative stress and mitochondrial dysfunction. As oxidative stress is an important factor in the induction of the mitochondrial permeability transition (mPT), we determined whether mPT plays a role in copper-induced neural cell injury. Cultured astrocytes and neurons were treated with 20 microM copper and mPT was measured by changes in the cyclosporin A (CsA)-sensitive inner mitochondrial membrane potential (Delta Psi m), employing the potentiometric dye TMRE. In astrocytes, copper caused a 36% decrease in the Delta Psi m at 12 h, which decreased further to 48% by 24 h and remained at that level for at least 72 h. Cobalt quenching of calcein fluorescence as a measure of mPT similarly displayed a 45% decrease at 24 h. Pretreatment with antioxidants significantly blocked the copper-induced mPT by 48-75%. Copper (24 h) also caused a 30% reduction in ATP in astrocytes, which was completely blocked by CsA. Copper caused death (42%) in astrocytes by 48 h, which was reduced by antioxidants (35-60%) and CsA (41%). In contrast to astrocytes, copper did not induce mPT in neurons. Instead, it caused early and extensive death with a concomitant reduction (63%) in ATP by 14 h. Neuronal death was prevented by antioxidants and nitric oxide synthase inhibitors but not by CsA. Copper increased protein tyrosine nitration in both astrocytes and neurons. These studies indicate that mPT, and oxidative and nitrosative stress represent major factors in copper-induced toxicity in astrocytes, whereas oxidative and nitrosative stress appears to play a major role in neuronal injury.     

Acute, subacute and chronic effect of cyclosporin-A on mean arterial pressure of rats with severe spinal cord contusion

Cyclosporin-A (CsA) protects and regenerates the neural tissue after spinal cord (SC) injury. These beneficial effects are achieved when CsA is administered at a dose of 2.5mg/kg/12h during the first 2 days after lesion. In view of these observations, it is realistic to envision that, CsA could be tested in SC-clinical trials. Since CsA is a drug strongly related to hypertension, results imperative to evaluate experimentally the effect of the above CsA-dose regimen on blood pressure. For this purpose, one hundred and twenty adult rats were subjected (10 groups) or not (10 groups) to SC-injury. Five injured and five Sham-operated groups received CsA. The remaining groups received only vehicle. Mean arterial pressure (MAP) was recorded from these animals at acute (6 and 24h post surgery; p.s.), subacute (96h), or chronic (30 days) stages of injury. In the latter, the therapy (CsA or vehicle) was administered only during the first 2 days p.s. or daily during 30 days of follow-up. The results of this study showed that SC-injury by itself induces a significant decrease of MAP during the acute and subacute phases of injury. CsA therapy was able to reestablish MAP parameters to control values in these phases. Regardless the therapy, a reestablishment of MAP was observed in chronic stages. Only the daily administration of CsA induced a significant increase in MAP, however; such variation remained into the normal ranges of MAP for rats. The potential benefits offered by CsA support its usefulness after SC-injury.     

Apoptosis and necrosis induced by cyclic mechanical stretching in alveolar type II cells

Alveolar type II (ATII) cells are exposed to mechanical stretch during breathing and mechanical ventilation. Increased stretch may contribute to lung injury. The influence of three stretching patterns (characterized by frequency [min(-1)] - increase in surface area [%]: S40-13, S60-13, S40-30) on parameters of apoptosis, necrosis, and membrane integrity of rat ATII cells was compared with that in static cultures. The S40-13 stretching pattern simulated normal breathing. The other patterns were chosen to study increased amplitude and frequency. There were no significant differences between the S40-13 group and static cultures. Lactic acid dehydrogenase (LDH) release and early apoptotic cells were significantly increased in S60-13 and S40-30 in comparison with static cultures (LDH: 0.089 +/- 0.014 microg/ml and 0.177 +/- 0.050 microg/ml versus 0.050 +/- 0.011 microg/ml; early apoptosis: 17 +/- 3.5% and 23 +/- 3.1% versus 9.7 +/- 1.4%) at 24 h. Necrosis was significantly increased only in the S40-30 group (13 +/- 2.4% versus 6.1 +/- 0.9% in static culture at 24 h). Captopril as well as L-Arginine prevented apoptosis and reduced apoptotic cells to static culture levels in the S40-30 group, but did not influence necrosis and LDH release. Increased mechanical stretch may contribute to lung injury by induction of apoptosis and necrosis in ATII cells. Apoptosis induced by high-amplitude mechanical stretch is prevented by captopril and L-Arginine.     

Applied relaxation and oral estradiol treatment of vasomotor symptoms in postmenopausal women

OBJECTIVE: The aim was to evaluate and compare the effects of applied relaxation and oral estradiol treatment on hot flushes, mood and psychological wellbeing in postmenopausal women. PATIENTS AND METHODS: In a prospective study, 30 postmenopausal women with vasomotor symptoms were randomized to applied relaxation or oral estradiol treatment during 12 weeks with 6 months follow-up. Number and severity of flushes were registered daily and Kupperman's Index and a general estimate of climacteric symptoms, Mood Scale and Symptom Check List were completed at baseline, 4, 8 and 12 weeks of treatment, and 3 and 6 months after therapy. RESULTS: After 12 weeks of treatment, the number of flushes/24 h decreased significantly over time in both treatment groups. In the group receiving applied relaxation, the mean number of flushes/24 h decreased from 6.0 (95% CI 4.5-7.6) to 3.0 (95% CI 2.1-3.9) after 12 weeks of treatment. The mean number of flushes/24 h was 1.7 (95% CI 0.7-2.5) at 6 months follow-up; i.e. a 72% decrease. In the estrogen group, the mean number of flushes/24h decreased from 8.4 to 0.8; i.e a 90% decrease in the number of flushes after 12 weeks of treatment. The significant change in flushes reached after 12 weeks of treatment and remained to 6 months after end of treatment in both groups. Estrogen therapy reduced flushes significantly faster than applied relaxation. General climacteric symptoms according to the Visual Analogue Scale and the Kupperman's Index decreased significantly over time in both groups. General mood (Mood Scale) increased significantly in the estrogen group, but not in the group receiving applied relaxation. Psychological wellbeing according to Symptom Checklist, increased significantly from baseline to 12 weeks in both groups. CONCLUSIONS: We suggest that applied relaxation may be used as an alternative treatment of vasomotor symptoms for postmenopausal women but should be further evaluated.     

Blunted DNA synthesis and delayed S-phase entry following inhibition of Cdk2 activity in the regenerating rat liver

Activation of the cyclin E/Cdk2 complex may play an important role in mid-G1/S-phase progression in proliferating mammalian cells. We evaluated the effect of targeted inhibition of Cdk2 activity by CYC202 (R-roscovitine) on hepatocytes proliferation in vivo after 70% partial hepatectomy (PH) in rats. In controls, Cdk2 activity and DNA synthesis peaked 24 h after PH. CYC202 abrogated Cdk2 activity, prevented BrdU incorporation and PCNA expression and increased mortality 24 h after PH. Cyclin E and Cdk2 protein expression and complex formation was not affected by CYC202 nor was cyclin D1, Cdk4 and c-ras mRNA expression. Two consecutive injections 8 and 20 h after PH were required to elicit the inhibitory effect of CYC202, which was lost when either the injection at 8 h or at 20 h was withheld. Cdk2 activity and cell progression resumed 48 h after PH in surviving animals suggesting that CYC202 induced a reversible inhibition of the cell cycle. Our results confirm an important role for Cdk2 in hepatocytes proliferation in the regenerating liver. We demonstrate that molecular events, including Cdk2 activation, occurring within the 8th and 24th hour after PH (G1/S-phase transition) are crucial in determining whether or not DNA synthesis and hepatocytes proliferation proceed normally after PH.     

Angiotensin II and fluid ingestion in old rats

Fluid ingestion was studied in Fischer 344/Brown Norway F1 rats aged 3, 12, 20, and 24 months of age. There was an age-related decrease in fluid ingestion when fluid intake was measured over 24 h. After water deprivation, 24- and 20-month-old rats drank less than 3- and 12-month-old rats. Twelve, 20-, and 24-month-old rats had less fluid intake associated with food deprivation than did 3-month-old rats. Three month old rats drank more fluid after angiotensin II than did 12-, 20-, and 24-month-old rats when expressed as fluid intake per kg body weight. These studies confirm that the rat is a reasonable model to study age-related hypodipsia.     

Ozone-induced acute tracheobronchial epithelial injury: relationship to granulocyte emigration in the lung.

To investigate the relationship between granulocyte emigration and epithelial injury in specific airway generations of the tracheobronchial tree following short-term ozone exposure, we exposed rhesus monkeys for 8 h to 0.00 (controls) or 0.96 ppm ozone with post-exposure periods of 1, 12, 24, 72, and 168 h in filtered air before necropsy. There were five control and three exposed monkeys for each of the post-exposure times for a total of 20 monkeys. Neutrophils isolated from peripheral blood and labeled with 111In-tropolonate were infused in the cephalic vein in unanesthetized monkeys (except the 1-h group) 4 to 5 h before necropsy. The trachea and microdissected bronchi (fourth and ninth generations) and respiratory bronchioles (fifteenth generation) from the right upper lobe of each monkey were examined by electron microscopy. Labeled neutrophil influx into lung tissue and bronchoalveolar lavage fluid (BALF) was maximal at 12 h and returned to baseline by 24 h after exposure. This was in contrast to total neutrophils (labeled and unlabeled) in BALF, which were significantly elevated through 24 h after exposure but returned to baseline by 72 h. Lavage protein was significantly elevated at 24 h after exposure but was at control levels at all other times. Morphometric observations showed epithelial necrosis at 1 and 12 h in the trachea and bronchioles but continued to be observed in significant numbers at 24 h after exposure in bronchi. A significant increase in the labeling index of epithelial cells was observed at 12 h only in bronchi. Epithelial necrosis and repair was associated with the presence of granulocytes in the epithelium and interstitium of all airway levels. However, eosinophils were maximally increased in the epithelium and interstitium of bronchi at 24 h after exposure when epithelial necrosis was maximal in these airways and when lavage protein was significantly elevated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Binding of [3H]inositoltrisphosphate and [3H]phorbol 12,13-dibutyrate in rat hippocampus following transient global ischemia: a quantitative autoradiographic study

An in vitro quantitative autoradiographic binding study of the phosphatidylinositol system ligands [3H]inositol 1,4,5-trisphosphate (IP3) and [3H]phorbol 12,13-dibutyrate (PDBU) to rat brain slices was performed at 6, 12, 24, 28 and 72 h following a 20 min ischemic injury. PDBU binding showed a transient 20% decrease in the dentate gyrus and the CA3 the first 24 h as well as a 50% decrease in the CA1 at 72 h. A 50% decline in IP3 binding was seen in all regions at 6-12 h except the pyramidal cell layer of the CA1. This downregulation of calcium mobilizing intracellular receptors is probably a defence against ischemic neuronal cell death.