Persistent hypertransaminasemia as the presenting findings of muscular dystrophy in childhood

Prolonged elevation of the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) is often attributed to hepatic diseases. However, these enzymes are also present in a variety of extrahepatic tissues, including skeletal muscle. Five children (all boys) were referred to the pediatric department of the National Taiwan University Hospital because of persistent elevation of serum aminotransferase activities. The ages of these children were between 4 months and 5.5 years. The neurological findings were all not remarkable. The initial ALT and AST values were 114-581 U/L and 183-700 U/L, respectively. Serum creatine kinase was checked first after 0 to 30 months follow-up and found to be markedly elevated (range, 10,557 U/L to 62,508 U/L). Muscle biopsies in the five cases all showed degenerating and regenerating myofibers with interstitial fibrosis. In Cases 3, 4 and 5, complete absence of dystrophin immunoreactivity was found. Genetic studies showed deletions in the DMD gene (exons 45-48 in case 2 and 49-50 in case 4). This experience indicates that occult muscle diseases should be taken into account in patients with unexplained long-lasting hypertransaminasemia and therefore measurement of serum creatine kinase activity and muscle biopsy should be done early for the correct diagnosis of muscular dystrophy.

Clinical benefit and response in patients with gastric cancer to weekly 24-hour infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (LV)

BACKGROUND

A prospective study evaluated the efficacy and correlation of different outcome measurements, including the WHO response criteria and clinical benefit (CB), to weekly high-dose 5-FU and LV for patients with advanced gastric cancer.

PATIENTS AND METHODS

Thirty-nine chemotherapy-naive patients were enrolled from Sep. 1996 to Oct. 1997. The treatment consisted of a 24-hour continuous infusion of 5-FU 2600 mg/m2 & LV 150 mg weekly for 6 weeks with a subsequent 2-week break. The responses were evaluated by CB and WHO criteria at the end of the 8th week, then at 8-week intervals.

RESULTS

There were 21 male and 18 female patients with a median age of 56 years. The median Karnofsky performance score was 70%. Thirty-six patients were evaluable for WHO criteria, and 12 (33.3%) had partial response, 12 (33.3%) had stable disease and 12 (33.3%) had progressive disease. Twenty-one of the 35 (60%) evaluable patients for CB were found to have a positive response. There was a significant correlation between WHO response and CB. The median survival was 10.5 months for CB responders, while the median survival among the CB non-responders was 5 months only.

CONCLUSIONS

This study found that this regimen yielded a 60% CB, despite a 33% WHO response rate. Improvement in CB resulted in an improvement in survival as well as the correlation between CB and WHO response, and suggested the value of CB as an alternative indicator for clinical response.

The fas and fas ligand pathways in liver allograft tolerance

The Fas and Fas ligand (Fas/FasL) pathways may play a central role in cytotoxicity or immunoregulation in liver transplantation. Here, in an attempt to examine the role of Fas/FasL on drug-free tolerance, we measured mRNA levels of Fas/FasL in livers by reverse transcriptase-polymerase chain reaction (RT-PCR), and also protein levels of Fas/FasL in livers by immunohistochemistry and in serum by dot blot assay. PVG recipients bearing DA livers showed serious rejection between post-operative (POD) days 7 and 14, but this rejection was naturally overcome without any immunosuppression. Fas gene and protein products were expressed on almost every cell in livers taken from naive rats, and at any time point in both syngeneic and allogeneic orthotopic liver transplantation (OLT) rats. In contrast, FasL mRNA in DA livers was detectable at POD 2, peaked at POD 14, and declined at POD 63 in allogeneic OLT (DA-PVG). Although the FasL gene was detectable in isografts at POD 14, its expression was much lower than in allografts. The time course and localization of FasL expression indicated that the expression of FasL gradually switched from infiltrating cells to hepatocytes when the rejection was naturally overcome and tolerance was induced in this OLT model. Soluble Fas could constitutively be detected at any time point in the serum of the tolerogenic OLT (DA-PVG) rats and was not diminished during the rejection phase. Soluble FasL peaked at POD 14 in allogeneic OLT, while sFasL was significantly lower in the serum of normal and syngeneic OLT rats. These findings suggest that the Fas and FasL pathways, including soluble forms, may contribute to the control of the immune response in this drug-free tolerance OLT model.

Relationship of the human cumulus-free oocyte maturational profile with in vitro outcome parameters after intracytoplasmic sperm injection

PURPOSE

We investigated whether the human oocyte maturational profile at the removal of cumulus/corona cells affects the fertilization rate and subsequent embryo quality after intracytoplasmic sperm injection.

METHODS

A total of 1011 oocytes from 150 cycles was included in this retrospective analysis. Cumulus-free oocytes that were in prophase or metaphase I of meiosis at the removal of cumulus/corona cells were incubated in vitro until they reached metaphase II (in vitro-matured oocytes) and were then immediately injected with a single spermatozoa. Oocytes that were in metaphase II at the removal of cumulus/corona cells (MII oocytes) received sperm injection after 3-4 hr of preinjection incubation.

RESULTS

The fertilization rate of the MII oocytes was significantly higher than that of in vitro-matured oocytes (81 vs 62%; P < 0.001). The cleavage rates were similar in the two groups (MII oocytes, 94%; in vitro-matured oocytes, 91%). However, MII oocytes had significantly higher percentages of good-quality embryos (grade 1-3 embryos, 87 vs 58%, P < 0.001) and embryos with high cumulative embryo scores (score 10-32 embryos, 62 vs 33%, P < 0.001). The mean cumulative embryo score of MII oocytes after fertilization was also higher than that of in vitro-matured oocytes (12.1 +/- 3.8 vs 8.8 +/- 3.4; P = 0.014).

CONCLUSIONS

MII oocytes that extruded the first polar body at the removal of cumulus/corona cells had better fertilization rates and embryo morphology than in vitro-matured oocytes that extruded the first polar body following the removal of cumulus/corona cells and in vitro culture.

Cytomegalovirus-encoded beta chemokine promotes monocyte-associated viremia in the host

Chemokine homologs are encoded by many large DNA viruses, suggesting that they contribute to control of host leukocyte transmigration and trafficking during viral infection. Murine cytomegalovirus carries a CC (beta) chemokine homolog gene giving rise to two related proteins, murine cytomegalovirus chemokine 1 and 2 (MCK-1 and MCK-2). MCK-1 peptide was found to induce calcium signaling and adherence in murine peritoneal macrophages. Cells bearing human chemokine receptor CCR3 and the human macrophage THP1 cell line were responsive to MCK-1. This pattern suggested that MCK-1 might act as an agonist, promoting leukocyte trafficking during viral infection. Consistent with this prediction, MCK-1/MCK-2 mutant viruses exhibit dramatically reduced peak levels of monocyte-associated viremia in experimentally infected mice. Thus, MCK-1/MCK-2 appears to promote host leukocyte migration to initial sites of infection and may be responsible for attracting monocytes or macrophages that efficiently disseminate virus in the host.

Improving the Anesthesiology Clerkship for Medical Students

With the current emphasizing primary care specialty, the number of the applicants for anesthesiology residency has declined. In consequence, the medical students' interest in taking the elective anesthesia clerkship was decreased. Through the program redesign, we have improved our anesthesiology clerkship. In order to attract the best and brightest medical students to choose anesthesiology as a career, continuing efforts to improve both quantity and quality of medical students' education in anesthesiology are crucial.

Three-dimensional facial model reconstruction and plastic surgery simulation

Facial model reconstruction and surgical simulation are essential to plastic surgery in today's medicine. Both can help surgeons to design appropriate repair plans and procedures prior to actual surgery. In this paper, we exploit a metamorphosis technique in our new design. First, using metamorphosis and vision techniques, we can establish three-dimensional facial models from a given photo. Second, we design several morphing operators, including augmentation, cutting, and lacerating. Experiments show that the proposed algorithms can successfully create acceptable facial models and generate realistically visual effects of surgical simulation.

Tracheal neurilemmoma mimicking bronchial asthma--a dilemma of difficult diagnosis: case report

Tracheal tumors are often overlooked as a cause of pulmonary symptoms until they reach an advanced state. They are often presented with a prolonged cough and shortness of breath. Most tracheal tumors in adults are cancerous (80% to 90%). Benign tracheal tumors are rare in adult patients. A case history is presented of a 19-year-old patient with a rare tracheal neurilemmoma. He was treated as having bronchial asthma initially, but his signs and symptoms did not improve with traditional therapy. The possibility of the presence of an upper airway obstruction was not raised until the typical "inspiratory tubular sound" was heard. Flow-volume loop testing, bronchoscopy, and three-dimensional computed tomography (3-D CT) confirmed the diagnosis of upper airway obstruction caused by a tracheal tumor. Therefore, surgical intervention rather than bronchoscopic removal was performed without difficulty. The patient was leading a stable life 8 months after a surgical resection. The presence of an upper airway obstruction can be proven by flow-volume loop testing and 3-D CT. Further pathologic confirmation can be accomplished by bronchoscopy. High suspicion of an upper airway obstruction such as a tracheal lesion should be raised when bronchial asthma patients fail to respond to conventional treatment.

Development of a device for immobilization of head and correlation of functional-anatomical brain images

BACKGROUND

The excellent resolution of brain imaging modalities has important contributions in the diagnosis of brain diseases. However, involuntary movement by the patient may cause poor image quality. In this study, we developed a device to help keep a patient's head immobilized during brain image acquisition, for comparison between each follow-up study, and for functional-anatomical image correlation.

METHODS

This device includes an acrylic material head supporter and a thermoplastic material facemask. The head supporter and the facemask can be firmly attached as a whole to support the head in a fixed position. Two capillary tubes filled with technetium-99m solution were placed perpendicularly on one side of the facemask as fiducial for imaging correlation between different studies. Ten patients, who each had two technetium-99m hexamethyl propyleneamine oxime (99mTc-HMPAO) brain single photon emission computer tomography (SPECT), were tested with this device for imaging.

RESULTS

Three-dimensional cine motion and sectional imaging were displayed and confirmed head immobilization in all of these studies. In addition, the 99mTc fiducial were useful in the comparison of head positions among the different studies. In five subjects, the device also proved to be useful in functional-anatomical correlation among SPECT, magnetic resonance imaging (MRI), and computed tomography (CT) images.

CONCLUSION

In conclusion, this device has been developed and found to be useful in (1) keeping patient's head immobilization, (2) keeping consistent head position for follow-up studies, and (3) SPECT, MRI and CT functional-anatomical imaging correlation.

The effect of tetrandrine and extracts of Centella asiatica on acute radiation dermatitis in rats

Radiation injury to the skin is one of the major limiting factors in radiotherapy. We designed this study using Sprague-Dawley rats to evaluate the reduction in skin injury achieved using natural products from plant extracts as protection. The acute skin reaction in tetrandrine- and Madecassol-treated animals appeared earlier, but was significantly less severe, than in the control group. The peak skin reactions in the tetrandrine group were less serious than those of the control group at three different radiation doses. At a high dose irradiation, the healing effect of tetrandrine is better than Madecassol and vaseline. The histologic findings indicate that tetrandrine and Madecassol are able to reduce acute radiation reactions by their anti-inflammatory activity.

Radiofrequency ablation of a right atriofascicular Mahaim fiber and two contralateral left free-wall accessory pathways

We report a rare combination of a right atriofascicular Mahaim fiber and two left-sided atrioventricular accessory pathways in a 57-year-old female presenting with an antidromic atrioventricular reciprocating tachycardia. Radiofrequency ablation was first targeted at the left lateral accessory pathway that served as the retrograde limb of the tachycardia. After elimination of the left lateral pathway, a bystander left posterolateral pathway was detected, and it too was successfully ablated. Although no tachycardia was reinducible, the Mahaim pathway was ablated because of its short effective refractory period. A discrete Mahaim potential recorded at the right atrial free-wall successfully guided the ablation.

Parathyroid hormone-related protein is a positive regulator of keratinocyte growth factor expression by normal dermal fibroblasts

Parathyroid hormone-related protein (PTHrP), an important factor in the pathogenesis of humoral hypercalcemia of malignancy, is produced by many normal tissues, including the skin, where it regulates keratinocyte growth and differentiation and dermal fibroblast function. Keratinocyte growth factor (KGF), a member of the fibroblast growth factor (FGF) family, is a secretory product of stromal cells and functions as a mediator of epithelial cell growth and differentiation. Phenotypes of the skin in several transgenic mouse models, in which the KGF and PTHrP genes have been overexpressed or disrupted, suggest that these two factors interact in vivo to regulate homeostasis of the skin. In this study, we investigated the effects of KGF on PTHrP secretion and expression by normal human foreskin keratinocytes (NHFK) and the effects of PTHrP on KGF secretion and expression by normal human dermal fibroblasts (NHDF) in vitro. N-terminal PTHrP(1-36) increased KGF secretion, protein expression and mRNA expression by NHDF in a dose-dependent manner, however, KGF did not regulate PTHrP expression and secretion by NHFK. By flow cytometry, PTHrP also increased the percentage of NHDF producing KGF. Our results indicate that PTHrP produced by keratinocytes is a potential paracrine regulator of KGF expression by dermal fibroblasts in vivo. This paracrine regulation may explain, in part, the epidermal atrophy seen in the PTHrP null mice and epidermal hyperplasia seen in transgenic mice overexpressing PTHrP in their basal keratinocytes. Our results also suggest that PTHrP is an important mediator for the healing of skin wounds and growth of neoplasms of squamous origin.

Outcomes after single injection caudal epidural versus continuous infusion epidural via caudal approach for postoperative analgesia in infants and children undergoing patent ductus arteriosus ligation

Adequate postoperative analgesia enhances deep breathing and minimizes respiratory complications after thoracotomy. This study compares postoperative outcomes after single injection caudal epidural vs continuous infusion epidural via caudal approach for postoperative analgesia in infants and children undergoing thoracotomy for patent ductus arteriosus (PDA) ligation. A retrospective chart review was performed for 27 children who had undergone PDA ligation. The children were divided into three groups. We compared patient demographics, surgical duration, anaesthesia duration, length of ICU stay, incidence of emesis requiring treatment, time required to establish regular oral intake, requirement for supplemental intravenous opioids during the first postoperative day, and length of hospital stay. For paediatric patients undergoing PDA ligation, postoperative analgesia with continuous infusion epidural via caudal approach produced shorter ICU stay, less occurrence of postoperative emesis, earlier oral intake, elimination of intravenous opioid supplementation, and shorter hospital stay compared with single injection caudal epidural techniques.

Weekly 24-h infusion of high-dose 5-flurouracil and leucovorin in patients with advanced gastric cancer

The effect of biochemical modulation of weekly high-dose 5-fluorouracil (5-FU) 24 h infusion by leucovorin (LV) in the treatment of 39 consecutive patients with advanced gastric cancer without prior chemotherapy from October 1996 to August 1997 was examined. There were 21 male and 18 female patients with a median age of 56 years. The regimen consisted of 5-FU 2600 mg/m2 and LV 150 mg administered by 24 h infusion weekly for 6 weeks followed by a 2 week break. The treatment was repeated every 8 weeks until disease progression, patient refusal or unacceptable toxicity. Placement of a central vascular device and a portable external infusion pump was required in all patients and was used for outpatient treatment. The response to treatment was evaluated every 8 weeks. A total of 395 chemotherapy treatments were given with a mean of 10 (2-24). This response rate was: 33% (12 of 36) partial response (PR) rate, 33% (12 of 36) stable disease (SD) and 33% (12 of 36) progressive disease (PD). In general, the toxicity was mild but two toxic deaths occurred, one due to neutropenic sepsis and the other due to hyperammonemia. The median time to progression was 4 months. The overall median survival was 7 months. The survivals of the PR, SD and PD were 12, 8 and 5 months, respectively. This regimen showed a modest activity against gastric cancer with acceptable toxicity. Weekly 24 h infusion of high-dose 5-FU with LV in an outpatient setting for patients with gastric cancer is feasible and deserves further study as a basis for combination therapy.

Cleft of the lip and palate in twins

BACKGROUND

Cleft lip and palate is one of the most common congenital anomalies in Taiwan. Its etiology remains unknown for the majority of the patients. The study of twins is a classic method for evaluating the relative roles of genetic and environmental factors in the formation of the anomaly.

METHODS

In this study, 37 pairs of twins and one set of triplets with cleft lip and palate were evaluated. Clinical data were collected for zygosity determination and analysis of etiologic factors. The concordance rate and heritability index were assessed.

RESULTS

The results showed that the concordance rate was 26% for all twins and 57% among the monozygotic pairs, which is higher than those rates for the Caucasian population. The heritability index was 53%, higher than the other reports as well. The influence of the environment could not be ruled out.

CONCLUSION

The results confirm a strong genetic role in the etiology of clefts in our patients. Environmental factors were acting as well. The findings in this study support the multifactorial threshold model in the development of cleft lip and palate.

Risk of transient hyperammonemic encephalopathy in cancer patients who received continuous infusion of 5-fluorouracil with the complication of dehydration and infection

From 1986 to 1998, 29 cancer patients who had 32 episodes of transient hyperammonemic encephalopathy related to continuous infusion of 5-fluorouracil (5-FU) were identified. None of the patients had decompensated liver disease. Onset of hyperammonemic encephalopathy varied from 0.5 to 5 days (mean: 2.6 +/- 1.3 days) after the initiation of chemotherapy. Plasma ammonium level ranged from 248 to 2387 microg% (mean: 626 +/- 431 microg%). Among the 32 episodes, 26 (81%) had various degrees of azotemia, 18 (56%) occurred during bacterial infections and 14 (44%) without infection occurred during periods of dehydration. Higher plasma ammonium levels and more rapid onset of hyperammonemia were seen in 18 patients with bacterial infections (p=0.003 and 0.0006, respectively) and in nine patients receiving high daily doses (2600 or 1800 mg/m2) of 5-FU (p=0.0001 and < 0.0001, respectively). In 25 out of 32 episodes (78%), plasma ammonium levels and mental status returned to normal within 2 days after adequate management. In conclusion, hyperammonemic encephalopathy can occur in patients receiving continuous infusion of 5-FU. Azotemia, body fluid insufficiency and bacterial infections were frequently found in these patients. It is therefore important to recognize this condition in patients receiving continuous infusion of 5-FU.

Vocal cord paralysis and hypoventilation in a patient with suspected Leigh disease

The authors report the case of a 16-month-old male with suspected Leigh disease, which was diagnosed on the basis of the clinical manifestations, abnormal lactate stimulation test, proton magnetic resonance spectroscopy, and neuroradiologic findings. Progressive stridor resulting from bilateral vocal cord paralysis and hypoventilation was evident. The authors suggest that for infants or children who exhibit vocal cord paralysis, mitochondrial disorders, such as Leigh disease, should be considered.

Effects of cord blood transfer on the hematopoietic recovery following sublethal irradiation in MRL lpr/lpr mice

The potential of cord blood (CB) to serve as a rich source of stem cells and stem cell factors is receiving increasing attention. In addition, perhaps because of the early ontogeny of these cells or the lack of surface antigens, cord blood stem cells do not appear to require close identity with the recipient. In the present pilot study, we investigated the presence of a hematopoiesis enhancing effect (HEE) by assaying the ability of human cord blood cells to augment hematopoiesis across a species barrier. For these experiments, autoimmune-prone MRL-Ipr/Ipr mice were exposed to sublethal levels of irradiation and cord blood administration to study the role of factors present in human cord blood in augmenting the rate of lymphopoiesis. This strain was chosen because of the increased presence of peripheral T and B subpopulations, namely the B-1 and CD4/CD8 double negative T-cell subpopulations, which do not arise directly from bone marrow precursors, but rather accumulate with age. MRL-Ipr/Ipr mice were sublethally irradiated and reconstituted with syngeneic bone marrow (BM) cells or with human cord blood cells or peripheral blood mononuclear cells (PBMC), or were left unreconstituted. At 2 weeks post-treatment, lymphoid populations in the spleen and lymph nodes were studied as a measure of hematopoiesis. Factors present in cord blood were able to augment hematopoiesis over that which occurred endogenously. At 2 weeks postirradiation, recipients of BM cells displayed the fastest rate of peripheral lymphoid recovery, nonreconstituted mice showed the slowest lymphoid recovery, and recipients of cord blood recovered their lymphoid populations at an intermediate rate. Similarly, myelopoiesis was increased in irradiated SJL/J recipients of human cord blood. Thus, human cord blood cells appear to produce/induce factors that may act as an adjunct to increase stem-cell activity.

Differences in the regulation of fibroblast contraction of floating versus stressed collagen matrices

To learn more about the regulation of contraction of collagen matrices by fibroblasts, we compared the ability of lysophosphatidic acid (LPA) and platelet-derived growth factor (PDGF) to stimulate contraction of floating and stressed collagen matrices. In floating collagen matrices, PDGF and LPA stimulated contraction with similar kinetics, but appeared to utilize complementary signaling pathways since contraction obtained by the combination of growth factors exceeded that observed with saturating concentrations of either alone. The PDGF-simulated pathway was selectively inhibited by the protein kinase inhibitor KT5926. In stressed collagen matrices, PDGF and LPA stimulated contraction with different kinetics, with LPA acting rapidly and PDGF acting only after an approximately 1-h lag period. Pertussis toxin, known to block signaling through the Gi class of heterotrimeric G-proteins, inhibited LPA-stimulated contraction of floating but not stressed matrices, suggesting that LPA-stimulated contraction depends on receptors coupled to different G-proteins in floating and stressed matrices. On the other hand, the Rho inhibitor C3 exotransferase blocked contraction of both floating and stressed collagen matrices. These results suggest the possibility that distinct signaling mechanisms regulate contraction of floating and stressed collagen matrices.

Acute retinal necrosis--early manifestation and successful treatment with steroid and acyclovir: case report

A healthy 19-year-old woman suffering from pain, redness, and blurred vision of her left eye came to our emergency unit for help. Initial examination revealed no light-perception, tenderness and marked inflammation of the left eye. There was severe inflammation both in the anterior chamber and vitreous cavity. Total retinal detachment accompanied by diffuse thickening of choroid was demonstrated using echography. Under the impression of panuveitis, oral steroids were given. The response of the left eye was dramatic but the patient complained of blurred vision of her right eye 2 days after steroid therapy. There was only mild reaction in the right eye; however, multiple granule-appearing white dots were found on the inferior two-thirds of the peripheral retina. The nummular white lesions increased in size and number and finally became confluent in the following days. The diagnosis was shifted to acute retinal necrosis and intravenous acyclovir was started while continuing systemic steroid therapy. The retinal necrosis began to consolidate four days after the administration of acyclovir and gradually regressed. We tapered the systemic steroids when the intra-venous acyclovir was shifted to oral form. The vitreous of the right eye remained clear during the follow-up period. The antiviral agent still suppressed the disease process even though steroids had been used beforehand. Furthermore, the systemic steroids seemed to ameliorate the vitritis and secondary complications in the right eye compared with the fulminant, disastrous course of the left eye.

The (-)-enantiomer of gossypol inhibits proliferation of stromal cells derived from human breast adipose tissues by enhancing transforming growth factor beta1 production

We report here that (-)-gossypol significantly inhibits the proliferation of stromal cells derived from human breast adipose tissues (human breast adipose stromal cells) in a dose-dependent manner. The mechanisms involved in the anti-proliferative action of (-)-gossypol on adipose stromal cells were also investigated. (-)-Gossypol stimulated transforming growth factor (TGFbeta1) secretion after 24 h, and RNase protection assay showed that TGFbeta1 mRNA levels were increased as well. We also observed that TGFbeta1 significantly inhibited the growth of human breast adipose stromal cells in a dose-dependent manner. When human breast adipose stromal cells were co-incubated with 5 microM (-)-gossypol and 50 microgram/ml of anti-TGF-beta1,-beta2,-beta3 antibody, growth inhibition caused by (-)-gossypol was completely abrogated. This study indicates that the anti-proliferative activity of (-)-gossypol on human breast adipose stromal cells may be mediated by changes in TGF 1 production.

Effects of ozone on ovalbumin sensitization in guinea pigs

The effects of ozone on allergen sensitization is still controversial. This study is aimed to clarify the effect of ozone on airway hypersensitivity to ovalbumin (OVA) in guinea pigs, by exposing them to ozone (3 ppm 2 hours daily) and OVA (1 gm/dL 10 min weekly) for two weeks. OVA specific IgG and airway hypersensitivity to methacholine were determined after the sensitization. The results demonstrated that there was a synergistic effect of ozone on OVA-induced IgG antibody production. OVA specific IgG was 0.51 +/- 0.1 U/mL and 0.46 +/- 0.1 U/mL using OVA and ozone alone respectively, which increased to 1.09 +/- 0.4 U/mL when both OVA and ozone were given simultaneously. Ozone exposure was able to cause airway hypersensitivity. The provocation dose of methacholine causing a 100% increase of airway resistance (PD 100 airway resistance) was 0.54 +/- 0.19 mg/mL and 1.17 +/- 0.30 mg/mL using OVA and ozone exposure alone, which had decreased to 0.49 +/- 0.18 mg/mL when both OVA and ozone were given simultaneously. There were macrophages around the peribronchial tissue in all guinea pigs except in the control. The macrophages in the group of OVA with ozone (24.2 +/- 7.2 cells/HPF) were significantly more than those in the OVA group (18.0 +/- 4.2 cells/HPF) and the ozone group (14.5 +/- 6.2 cells/HPF). When OVA-presensitized guinea pigs were exposed to ozone immediately or daily for two weeks, a restrictive type of lung function impairment with similar airway hypersensitivity post ozone exposure was observed. In conclusion, guinea pigs exposed to ozone in conjunction with aeroallergen may not only facilitate the damage of the airway but also enhance antibody production to the aeroallergen. The ozone-induced airway inflammation might have a contributing effect on OVA induced airway hypersensitivity in guinea pigs.

The adsorption of heavy metals by different sorbents under various incineration conditions

The emission of heavy metals can be controlled by adding solid sorbents into the combustion chamber during incineration processes. The objective of this work was to experimentally study the adsorption efficiency of different sorbents for heavy metals under various incineration conditions. Each sorbent has its optimum operating temperature. Kaolinite and aluminum oxide have the best adsorption efficiency at 800 degrees C, and bauxite is at 700 degrees C. The adsorption efficiencies of the three sorbents for the four heavy metals all follow the sequence of Pb > Cu > Cr > Cd. The presence of inorganic chloride (NaCl) and sulfate (Na2SO4) increases the adsorption efficiency of the sorbents, but organic chloride PVC decreases the adsorption efficiency.