[Modulation of tonic herbs on the immune cell inhibition in stressed model animal and its possible mechanism]

OBJECTIVE

To observe the effect of tonic herbs on the immune cell proliferation in stressed mice.

METHODS

A model of stressed mice was built to observe the effect of such tonic herbs as Tusizi, Chuanduan; Nüzhenzi, Gouqizi on the calcium concentration in cytoplasm in the process of immune cell reproduction, as well as on the membrane fluidity of splenetic lymphocytes, IL-2, IL-2R and cell period.

RESULTS

The tonic herbs could improve the proliferation ability of spleen lymphocyte in the stressed mice, reduce the calcium concentration, and recover the fluidity of cell membrane. They could also improve the activity of IL-2 and increase the amount of IL-2R cell(P < 0.01). The combination of the four tonic herbs proved more effective, facilitating the cell into DNA synthetic period and reducing the retention period in G0/G1 (P < 0.01).

CONCLUSION

Tonic herbs can modulate the reproductive function of the spleen lymphocyte and relieve the unfavorable response of the stress on the organism.

A new screening measure to identify potential carbon monoxide hotspots

To demonstrate conformity of transportation projects to National Ambient Air Quality Standards in accordance with State Implementation Plans, the U.S. Environmental Protection Agency (EPA) uses intersection level of service (LOS) as one of its major criteria for screening for potential carbon monoxide (CO) hotspots. Although intersection LOS is a measure of traffic volume, signal timing, and related congestion and delay, the assigned level reflects only the computed averaged stopped delay (ASD) per vehicle at the intersection. Thus, intersections can often operate at the same LOS but produce vastly different levels of predicted CO concentrations. For example, a two-lane approach operating at LOS D will produce very different levels of CO than a five-lane approach also operating at LOS D. This study explores the effectiveness of the LOS D criterion as a screen for identifying potential CO hotspots. The study results indicate that LOS is a poor predictor of potential CO hotspots when compared to results generated with the EPA-recommended micro-scale model CAL3QHCr. To more consistently screen out those intersections that will not be identified as CO hotspots using the micro-scale models, a new criterion, equivalent red-time vehicles (ERTV), is introduced. The modeling results using ERTV suggest that it is a more robust measure for identifying potential CO hotspots, and conversely, screening out those intersections that are not likely to be identified as hotspots using micro-scale simulation results.

[A clinicopathologic study on eight cases of cystic and solid tumors of pancreas]

OBJECTIVE

To study the clinicopathologic characteristics, differentiation patterns and histogenesis of cystic and solid tumors of the pancreas (CSTP).

METHODS

8 cases of CSTP were studied using histologic (HE and PAS), immunohistochemical (S-P method) and electron microscopic techniques.

RESULTS

All the patients were adolescent and young adult females, 14-33 years in age (mean 25.3 years) without recurrence after tumor resection. The mean diameter of tumors was 9.6 cm, all encapsulated. Histological examination showed presence of solid sheets, pseudopapillary, in all of the cases. Hemorrhage, foam cells, and cholesterol crystals were often found. Immunohistochemically, 8 cases were positive for alpha(1)-AT and lysozyme; 6 cases expressed vimentin, 2 cases expressed actin, and CgA-positive cells found in the tumor cell nests in one case. All of the cases showed PR, and 4 cases showed ER positive immunoreactivity in the majority of tumor cells, but negative for CK AE1, CK AE3, EMA, Synaptophysin, ACTH, gastrin, somatostatin, insulin, and glucogan in all the cases. Electron microscopy of 3 cases showed evidences of polymorphism in differentiation of the tumor cells, including the transitional appearance into ducts, acinus, and endocrine cells. Weibel-Palade body found in tumor cells in one out of 8 cases.

CONCLUSIONS

(1) CSTP is a distinct clinicopathologic entity in young female patients with a benign clinical course. (2) CSTP develops from primitive pancreatic cells, with the potentiality of developing into ducts, acinus, and endocrine cells.

[Experimental study on the effect of nourishing yin and tranquilizing of yangyin anshen koufuye]

Yangyin Anshen Koufuye could obviously decrease the spontaneous activity of rats, effectively shorten the process of falling into sleep of normal rats which were injected pentobarbital sodium and prolong the sleeping time. The effect of sedation and hypnotism were the same as Zhaoren Anshen Koufuye. Yangyin Anshen Koufuye also could markedly reduce the serum tensity of T3, T4 of hyperthyroid rats, which equaled to TCM's deficiency of yin. It also could prevent the glycogen content of liver from decreasing, decrease heart rate, resist weight losing, thus to show the effect of nourishing Yin and tranquilizing.

[Common mutation analysis for patients found in Tianjin area with glucose-6-phosphate dehydrogenase deficiency]

OBJECTIVE

To study the types of glucose-6-phosphate dehydrogenase (G6PD) gene mutation in North China and to find the relationship between the mutations and population emigrants.

METHODS

DNA samples from 22 unrelated patients(21 male and 1 female) with G6PD deficiency from Tianjin area in North China were studied for the three common mutations by using both mismatched primers mediated polymerase chain reaction/ restriction enzyme analysis and dideoxy fingerprinting methods.

RESULTS

Eight patients(8/22, 36.4%) were found to have the mutation R459L(1376G-->T), and seven patients (7/22, 31.8%) were found to have the mutation R463H (1388G-->A). In three of (3/7) other seven patients (7/22), H32R(95A-->G) were detected; one patient (1/3) was identified to have H32R (95A-->G) mutation.

CONCLUSION

The three common mutations in South China are also found in North China. However, most of the patients in Tianjin are also the later generations of Southern emigrants.

[Expression detection and location analysis of BstNI isoschizomer restriction-modification system gene]

Some genetic markers of E. coli HB101 and JM110 were identified, two bacterial strains were used as recipients respectively to detect the expression of a restriction endonuclease(R) gene and a methylase(M) gene of BstNI isoschizomer restriction-modification system. DNA fragment containing the R-M genes was deleted unilaterally with exoIII and 23 deletion subclones were obtained. According to the Enzyme activity of each subclone, R and M gene were located respectively at the regions of 0.2-->1.4 kb and 1.5-->3.3 kb from cloning site PstI. Analysis showed that the R. M system belongs to type II, two genes are controlled by the different promoters; the recognition sequence of this system is the same as that of DNA-cytosine methyltransferase(Dcm), the latter's methylation function can resist the R enzyme. It was interesting that the recombinant plasmid with an R+ M- genotype appeared to be lethal to dcm+ hosts yet. This indicated that the M gene closely linking to R gene is of critical importance for the existence of the R-M system in process of evolution.

[Determination of high temperature compressive strength and refractory degree of die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the high temperature properties of the refractory die material compatible with slip casting core.

METHODS

To prepare three cylindrical specimens (phi 10 x 15 mm) and determine their compressive strength at 1000 degrees C: to make four specimens in flat-topped cone for determining the practical refractory degree by decreasing the pressing temperatures in a sequence of 1420, 1400, 1350 and 1100 degrees C.

RESULTS

The compressive strength of this material was 17.8 MPa at 1000 degrees C. Its practical refractory degree was higher than 1100 degrees C.

CONCLUSION

The high temperature properties of the refractory die material that we developed meet the demand of slip casting core of sintered powder.

[Study on the contamination of algae and microcystins in water sources of Zhengzhou City]

Planktonic algae and microcystins (MCYST) were detected constantly in water sources of Zhengzhou City from 1996 to 1997. There is significant seasonal variation of the density of algae. The peak of algae occurring in February and December is about 1,068,000/L. The contents of MCYST in July, 1995 and in January, 1996 were over 200 ng/L. According to the Carlson's trophic state index(TSI), and indexes of total nitrogen, phosphorus, COD value and algae density, an eutrophication of water source having emerged in Zhengzhou is considered.

Metabolic interactions between mibefradil and HMG-CoA reductase inhibitors: an in vitro investigation with human liver preparations

AIMS

To determine the effects of mibefradil on the nletabolism in human liver microsomal preparations of the HMG-CoA reductase inhibitors simvastatin, lovastatin, atorvastatin, cerivastatin and fluvastatin.

METHODS

Metabolism of the above five statins (0.5, 5 or 10 microM), as well as of specific CYP3A4/5 and CYP2C8/9 marker substrates, was examined in human liver microsomal preparations in the presence and absence of mibefradil (0.1-50 microM).

RESULTS

Mibefradil inhibited, in a concentration-dependent fashion, the metabolism of the four statins (simvastatin, lovastatin, atorvastatin and cerivastatin) known to be substrates for CYP3A. The potency of inhibition was such that the IC50 values (<1 microM) for inhibition of all of the CYP3A substrates fell within the therapeutic plasma concentrations of mibefradil, and was comparable with that of ketoconazole. However, the inhibition by mibefradil, unlike that of ketoconazole, was at least in part mechanism-based. Based on the kinetics of its inhibition of hepatic testosterone 6beta-hydroxylase activity, mibefradil was judged to be a powerful mechanism-based inhibitor of CYP3A4/5, with values for Kinactivation, Ki and partition ratio (moles of mibefradil metabolized per moles of enzyme inactivated) of 0.4 min(-1), 2.3 microM and 1.7, respectively. In contrast to the results with substrates of CYP3A, metabolism of fluvastatin, a substrate of CYP2C8/9, and the hydroxylation of tolbutamide, a functional probe for CYP2C8/9, were not inhibited by mibefradil.

CONCLUSION

Mibefradil, at therapeutically relevant concentrations, strongly suppressed the metabolism in human liver microsomes of simvastatin, lovastatin, atorvastatin and cerivastatin through its inhibitory effects on CYP3A4/5, while the effects of mibefradil on fluvastatin, a substrate for CYP2C8/9, were minimal in this system. Since mibefradil is a potent mechanism-based inhibitor of CYP3A4/5, it is anticipated that clinically significant drug-drug interactions will likely ensue when mibefradil is coadministered with agents which are cleared primarily by CYP3A-mediated pathways.

Difference in the burst patterns of digastric and mylohyoid activities during feeding in the freely behaving rabbit

Burst patterns in the digastric, mylohyoid, and masseter muscles and the resultant jaw movement orbits during chewing and swallowing were investigated in the freely behaving rabbit. Activities in the posterior mylohyoid fibers consisted of two continuous bursts. Peaks in the first burst of the posterior fibers occurred in the middle part of opening and preceded the digastric burst. Peaks in the second burst occurred in the final part of opening and coincided with those in the working side of the digastric burst. After removal of the bilateral digastric muscles, the gape size during chewing was largely reduced in the final part of opening and in the early part of closing. The results suggest that (a) the digastric may have a role in opening the mandible widely beyond the rest position but may not have a major role in the control of the horizontal (mediolateral) jaw movement, (b) the posterior mylohyoid fibers may have a function as an elevator of the tongue in the early part of opening, and (c) the posterior mylohyoid fibers may have a function as a depressor of the jaw in the late part of opening. Electromyographic burst in the mylohyoid muscle began with marked activity in the mid-closing phase. The results support a role for the mylohyoid muscle as a leading muscle of swallowing. Swallowing events in the rabbit are easily distinguished from the activities of the mylohyoid muscle and the thyrohyoid muscle.

Immunoregulatory role of CD8alpha in the veto effect

BACKGROUND

Allogeneic bone marrow cell (allo-BMC) infusion induces tolerance to incompatible renal allografts in rhesus macaques after depletion of peripheral T lymphocytes with cytolytic anti-T cell antibodies. The tolerogenic effect of allo-BMC, ascribed to a veto mechanism, associates with specific functional deletion of antidonor cytotoxic T lymphocyte precursor (CTLp), and is dependent on a CD8+ donor BMC subset. In previous studies, the CD8 molecule was implicated by loss of suppression after blocking interaction between CD8 on allo-BMC and major histocompatibility complex class Ialpha3 domain on CTLp. CD8 cross-linking on BMC induced secretion of active transforming growth factor-beta1 (TGF-beta1), suggesting a regulatory mechanism(s) operating via a CD8-mediated signaling pathway.

METHODS

CD8 on rhesus cells was cross-linked using IgG-conjugated beads, and TGF-beta1 mRNA and protein were quantified. CD8+ cells were tested for veto activity by mixed lymphocyte reaction (MLR)-induced cell-mediated lymphocytotoxicity (CML) assay. Activated rhesus T cells exposed to TGF-beta1 were examined for apoptosis by TdT-mediated end-labeling and annexin staining.

RESULTS

CD8 cross-linking induces accumulation of TGF-beta1 mRNA and protein. Both CD3- CD8+CD16+ and CD3+ CD8+CD16- subsets of allo-BMC up-regulate TGF-beta1 mRNA after CD8 cross-linking, and exhibit veto activity. The CD3-CD8+CD16+ subset expresses more TGF-beta1 mRNA and increased veto activity at low BMC/CTLp ratios. Exposure of activated T cells to TGF-beta1 induces apoptosis.

CONCLUSIONS

CD8+ allo-BMC are enriched for veto activity and activation via CD8 induces TGF-beta1 mRNA and protein accumulation. These results agree with the hypothesis that paracrine TGF-beta1 may be involved in peripheral deletion of alloreactive CTLp by CD8+ allo-BMC. We suggest that TGF-beta1 overexpression by donor lymphohematopoietic cells may enhance tolerance induction.

[A clinico-pathological study of neuroendocrine tumors in stomach]

OBJECTIVE

To study the pathological classification of gastric neuroendocrine tumors and its clinico-pathological significance.

METHODS

Paraffin sections of totally 52 gastric neuroendocrine tumors including 42 carcinoid tumors were studied with immunohistochemical technique, which involved 9 endocrine markers of hormones antibodies and electronic microscopy for investigating the endocrine cells and the contiguous gastric mucosa of the neuroendocrine tumors.

RESULTS

The 52 gastric neuroendocrine tumors were divided into three types: Type I, carcinoid, associated with atrophic gastritis, altogether 26 cases. Tumor extension was limited in the mucosa or submucosa, accompanying with hypergastrinemia and G cell hyperplasia. This type is consistently preceded by and associated with generalized proliferation of endocrine cells in the mucosa at fundus. Type II, carcinoid of sporadic type, totally 16 cases, not associating with hypergastrinemia, was more aggressive. Type III, Neuroendocrine carcinomas (10 cases), were highly aggressive tumors.

CONCLUSION

A correct identification of different types of gastric endocrine tumors is important and implicit for the treatment and prognosis of neuroendocrine tumors.

Pharmacological effects of methamphetamine and other stimulants via inhalation exposure

The effects of methamphetamine-HCl, methcathinone-HCl, cocaine and ephedrine on locomotor stimulation were compared between inhalation exposure and i.v. injection in mice. Methamphetamine-HCl was readily volatilized upon heating at 300 degrees C in a glass pipe with only trace amounts of amphetamine being produced. The ED50 dose (9.4 and 6.5 mumol/kg for inhalation exposure and i.v. injections, respectively) and biodisposition of methamphetamine-HCl were similar for both routes of administration. Methcathinone-HCl and cocaine were readily volatilized. Their dose response profiles also appeared similar for both routes of administration. Ephedrine did not appear to be easily volatilized and was only effective in stimulating locomotor activity after i.v. administration. These findings indicate that inhalation exposure to methamphetamine-HCl, cocaine and methcathinone possess similar pharmacological characteristics as the i.v. route of administration. In particular, this model may have implications in predicting the pharmacological activity of various stimulants via the inhalation route of administration.

Inhibition of glycogen synthase kinase 3beta activity regulates proliferation of cultured cerebellar granule cells

Insulin-like growth factor I (IGF-I) is mitogenic for several types of neuronal progenitors including cerebellar granule neuron progenitors. The present study confirms that IGF-I can function as a mitogen in purified cultures of cerebellar granule cells and identifies intracellular signal transduction molecules that mediate this mitogenesis. In cultured granule cells, IGF-I inhibits GSK-3 activity and leads to phosphorylation of serine9 an inhibitory site on GSK-3beta. Phosphoinositide 3-kinase (PI3-K) activation by IGF-I can lead to phosphorylation and inactivation of GSK-3. A PI3-K inhibitor, LY294002, completely inhibited IGF-I-induced proliferation with half-maximal inhibition occurring at a concentration (1.5 micrograms) close to its reported IC50 value for inhibition of PI3-K. Lithium chloride (LiCl), a direct inhibitor of GSK-3beta, can alone stimulate granule cell proliferation and enhance proliferation induced by IGF-I. LiCl can reverse the inhibitory effect of LY294002 on granule cell proliferation suggesting that GSK-3 inhibition may be downstream of PI3-K activation in IGF-I's mitogenic pathway. Experiments further show that the expression of a dominant active form of GSK-3beta antagonizes IGF-I-induced mitogenesis. These studies support a role for inhibition of GSK-3beta activity in the signal transduction pathway by which IGF-I regulates granule neuron progenitor proliferation.

Prolyl endopeptidase from Sphingomonas capsulata: isolation and characterization of the enzyme and nucleotide sequence of the gene

Prolyl endopeptidase (prolyl oligopeptidase, EC 3.4.21.26) was purified from Sphingomonas capsulata IFO 12533, and its gene was cloned and expressed in Escherichia coli. The recombinant enzyme was markedly inhibited by diisopropyl phosphofluoridate and hardly affected by SH reagents or metal chelators, similar to the native enzyme purified from S. capsulata. Nucleotide sequencing analysis revealed an open reading frame of 2169 bp, coding for a protein of 723 amino acids with a predicted molecular weight of 78,433. The amino acid sequence was 39.6, 45.3, 38.9, and 38.3% homologous to Flavobacterium meningosepticum, Aeromonas hydrophila, porcine brain, and human T cell prolyl endopeptidase, respectively. A region near the C-terminus and the region containing the putative catalytic triad residues were highly conserved. The enzyme was crystallized by the hanging drop vapor diffusion method, using ammonium sulfate as a precipitant.

[Successful media exchange and network communication of CT digital image]

The digital image standard in medical is discussed. Based on the DICOM standard by using the media exchange and establishing the network communication between PC and CT system, we successfully acquired the CT original digital image and convert it to DICOM standard image. The CT image can easitly be read and adjusted on the PC platform.

The effect of sequential injuries on splanchnic perfusion and eicosanoid release

BACKGROUND

This study examines the hypothesis that sequential burn injury followed by intraabdominal sepsis induces significantly greater splanchnic hypoperfusion and reduced intestinal PGI2 release than either injury independently.

MATERIALS AND METHODS

Anesthetized Sprague-Dawley rats were randomized to one of four groups: BURN (45% body surface area scald burn) + cecal ligation and puncture (CLP); BURN alone; CLP alone; or uninjured controls (SHAM). Twenty-four hours following injury, superior mesenteric artery (SMA) blood flow was measured with a doppler flow probe. Splanchnic eicosanoid release (6-keto-PGF1alpha, metabolite of PGE2; TxB2, metabolite of TxA2; and PGE2) was measured in mesenteric venous effluent utilizing an isolated, perfused bowel preparation.

RESULTS

SMA blood flow was no different than that of controls 72 h following BURN injury alone; whereas CLP alone resulted in a 80% reduction in splanchnic blood flow when compared with controls (P < 0.001). SMA blood flow in animals sustaining BURN + CLP was only modestly reduced from controls (P = 0.04) and 3.6 times greater than that of animals sustaining CLP alone (P < 0.001). PGI2 was the dominant eicosanoid released by the intestine with levels 10 times greater than TxB2 and nearly 50 times greater than PGE2. CLP either alone or when combined with BURN was associated with a 60% decrease in splanchnic PGI2 release when compared to controls (P < 0.05).

CONCLUSIONS

These data suggest that moderate BURN injury in rats attenuates the severe reduction in splanchnic perfusion associated with intraabdominal sepsis and that this occurs despite profound reductions in the release of the endogenous splanchnic vasodilator PGI2.

Role of Mxi1 in ageing organ systems and the regulation of normal and neoplastic growth

Mxi1 belongs to the Mad (Mxi1) family of proteins, which function as potent antagonists of Myc oncoproteins. This antagonism relates partly to their ability to compete with Myc for the protein Max and for consensus DNA binding sites and to recruit transcriptional co-repressors. Mad(Mxi1) proteins have been suggested to be essential in cellular growth control and/or in the induction and maintenance of the differentiated state. Consistent with these roles, mxi1 may be the tumour-suppressor gene that resides at region 24-26 of the long arm of chromosome 10. This region is a cancer hotspot, and mutations here may be involved in several cancers, including prostate adenocarcinoma. Here we show that mice lacking Mxi1 exhibit progressive, multisystem abnormalities. These mice also show increased susceptibility to tumorigenesis either following carcinogen treatment or when also deficient in Ink4a. This cancer-prone phenotype may correlate with the enhanced ability of several mxi1-deficient cell types, including prostatic epithelium, to proliferate. Our results show that Mxi1 is involved in the homeostasis of differentiated organ systems, acts as a tumour suppressor in vivo, and engages the Myc network in a functionally relevant manner.

[Determination of linear sintering shrinkage rate of slip-casting infiltrated ceramic]

This study tested the linear sintering shrinkage (SS) rate of ceramic infiltrated with different glasses (Vita In-ceram, G I-I La, G I-II La, G I-II Ce), the results showed that the linear SS rate was 0.08%-0.32%, which occurred mainly in the firing stage of alumina (P < 0.05) and glass infiltration had no influences on the dimensional stability of ceramic(P > 0.05). It suggests that the effects of glass infiltration on the dimensional stability of GI glasses were comparable with that of Vita In-ceram.

Alveolar macrophage response to remote organ injury

Intestinal reperfusion (IR)-induced pulmonary edema has been related to endogenous pulmonary thromboxane A2 (TxA2) release. This study examines the hypothesis that alveolar macrophages (aMphis) activated during IR are an important cellular source of TxA2 in this model. Anesthetized Sprague Dawley rats underwent 120 min of intestinal ischemia and 60 min of reperfusion (IR) or sham operation (Sham). aMphis were isolated by bronchoalveolar lavage and incubated in Krebs buffer for 30 min, after which the supernatant was analyzed for TxB2 (metabolite of TxA2) and prostaglandin E2. Other parameters of aMphi activation measured included lysosomal enzyme release (beta-glucuronidase), superoxide (O2-) release, and procoagulant activity. aMphis from animals sustaining IR generated more than twice as much TxA2 and prostaglandin E2 as did those isolated from controls (p < .05). Other evidence of aMphi activation included a nearly 100-fold increase in procoagulant activity, a 7-fold increase in beta-glucuronidase release, and a 2.5-fold increase in O2- release over that of controls (p < .05). These data suggest that TxA2 is a major eicosanoid product of aMphis during IR and that aMphis may be an important cellular participant in IR-induced pulmonary microvascular injury, either directly by releasing O2-, lysosomal enzymes, and pro-coagulant factors, or indirectly by generating TxA2.

[Minor alkaloids from the capsule of Papaver nudicaule L]

Two minor alkaloids were isolated from the capsule of Papaver nudicaule. On the basis of physicochemical methods and spectroscopic analysis, they were identified as chelidonine, 5-hydroxy-2-hydroxymethylpyridine. Chelidonine was isolated from this plant and 5-hydroxy-2-hydroxymethylpyridine was isolated from genus for the first time.

Thromboxane A2 mediates increased pulmonary microvascular permeability after intestinal reperfusion

This study examines the hypothesis that intestinal reperfusion (IR)-induced pulmonary thromboxane A2 (TxA2) release increases local microvascular permeability and induces pulmonary vasoconstriction. Sprague-Dawley rats underwent 120 min of intestinal ischemia and 60 min of IR. Sham-operated animals (Sham) served as controls. After IR or Sham, the pulmonary vessels were cannulated, and the lungs were perfused in vitro with Krebs buffer. Microvascular permeability was quantitated by determining the filtration coefficient (Kf), and pulmonary arterial (Ppa), venous (Ppv), and capillary (Ppc) pressures were measured to calculate vascular resistance (Rt). After baseline measurements, imidazole (TxA2 synthase inhibitor) or SQ-29,548 (TxA2-receptor antagonist) was added to the perfusate; then Kf, Ppa, Ppv, and Ppc were again measured. The Kf of lungs from IR animals was four times greater than that of Sham (P = 0.001), and Rt was 63% greater in the injured group (P = 0.01). Pc of IR lungs was twice that of controls (5.4 +/- 1.0 vs. 2.83 +/- 0.3 mmHg. IR vs. Sham, respectively; P < 0.05). Imidazole or SQ-29,548 returned Kf to baseline measurements (P < 0.05) and reduced Rt by 23 and 17%, respectively (P < 0.05). IR-induced increases in Pc were only slightly reduced by 500 micrograms/ml imidazole (14%; P = 0.05) but unaffected by lower doses of imidazole (5 or 50 micrograms/ml) or SQ-29,548. These data suggest that IR-induced pulmonary edema is caused by both increased microvascular permeability and increased hydrostatic pressure and that these changes are due, at least in part, to the ongoing release of TxA2.