Characteristic of polychlorinated dibenzo-p-dioxins and dibenzofurans in fly ash from incinerators in china

Fly ash from municipal solid waste (MSW), medical waste (MW) and electrical power plant (EPP) incinerators were analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The study showed that the PCDD/F levels in fly ash were EPP<MSW<MW. The homologue profiles of PCDD/Fs in fly ash produced from waste incinerators were similar. However, the homologue profiles of PCDD/Fs in fly ash from electrostatic precipitator (ESP) of electrical power plant were different from that from waste incinerator. The strong correlation was found between the concentration of 2,3,4,7,8-PeCDF and the I-TEQ value of fly ash regardless of the different fly ashes sources.

Motorcycle exhaust induces reproductive toxicity and testicular interleukin-6 in male rats

Motorcycle exhaust (ME) from two-stroke engines contains many toxicants and poses a potential health hazard. The major objectives of the present study were to investigate the male reproductive toxicity of ME and the underlying mechanisms of toxicity. Male Wistar rats were exposed to ME by inhalation 1 h each in the morning and afternoon, Monday through Friday. Exposures to 1:50 diluted ME for 4 weeks or to 1:10 diluted ME for 2 and 4 weeks showed concentration- and time-dependent decreases of testicular weight, spermatid number, and cauda epididymal sperm number. Subsequent studies were done using 4-week exposure to 1:10 diluted ME. ME caused histopathological changes including testicular spermatocytic necrosis and seminiferous tubule atrophy and cauda epididymal formation of clusters of pyknotic and necrotic sperm cells. ME-exposed male rats mated with untreated females showed decreases of male mating index and female fertility index and an increase of implantation site loss. ME decreased 7-ethoxycoumarin O-deethylase and superoxide dismutase activities but induced proinflammatory cytokine interleukin-6 (IL-6) messenger RNA (mRNA) in the testis. Male rats were exposed to ME with or without cotreatment with 50 mg/kg vitamin E orally for 4 weeks. ME decreased serum testosterone concentration. This effect was reversed by cotreatment with vitamin E. ME decreased testicular spermatid number and induced IL-6 mRNA and protein. These effects were also reversed by the vitamin E cotreatment. The present findings show that ME causes male reproductive effects and induces testicular IL-6 in rats by mechanisms involving induction of oxidative stress and inhibition of steroidogenesis.

Effects of calcium-based sorbents on PCDD/F formation from pentachlorophenol combustion process

Calcium-based sorbents are widely employed to reduce the acidic gases emission from combustion processes, and also have effects on trace organic pollutants formation and emission. Batch experiments were conducted to investigate the effects of calcium-based sorbents on pentachlorophenol (PCP) forming PCDDs/Fs during high temperature combustion processes. The results indicated that highly chlorinated PCDD/F homologues were the predominant dioxin products from PCP thermo decomposition, and only minor increasing of PCDDs happened when Ca/Cl ratio was lower than 1, while a major jump occurred when Ca/Cl ratio increased from 1 to 2. The CaO addition clearly promoted the production of all chlorinated dibenzo-p-dioxins homologue and 4-7DFs homologue. Comparison of total PCDD/F emission and its I-TEQ for three different calcium-based sorbents addition (CaO, CaCO3, basic fly ash) indicated that CaO and fly ash containing CaO had almost the same promotion effects on PCDDs/Fs originated from PCP, while CaCO3 inhibit PCDD/F formation greatly with inhibition efficiency up to 70%. Such effects may be partly proved by the observed clearly different micro-surface structures of their reaction residues. The mechanism of CaO on condensation and dechlorination reactions for PCP forming PCDDs and acid-base interaction were proposed to speculate the promotion effects of CaO, and the reaction precedence was used to speculate the inhibition effects of CaCO3 on PCDDs/Fs originated from PCP. The results of the present paper might be useful for the industrial application of calcium-based sorbents to control PCDD/F emission.

Degradation of PCDD/Fs by mechanochemical treatment of fly ash from medical waste incineration

The potential of mechanochemical treatment (MC) to degrade PCDD/Fs contained in fly ash was tested via grounding with and without calcium oxide (CaO) under atmospheric pressure. Three types of fly ash collected from medical waste incineration were compared, originating either from rotary kiln fluidized bed multi-stage incinerator using activated carbon spray (FA1, FA2), or a simple stoker incinerator without activated carbon spray (FA3). In test I: CaO to FA1 mixed at ratio of 6-60% was milled at rotational speed of 350 rpm; in test II: FA2 and FA3 without CaO were milled at rotational speed of 400 rpm. The duration of the tests was 2h. The results from the present study indicate that (1) under two test conditions of with and without CaO, PCDD/Fs contained in real fly ash both can be degraded by mechanochemical treatment, (2) under condition of blending with CaO, the degradation efficiency of PCDD/Fs increased with increasing ratio of CaO, (3) the degradation efficiency of PCDD/Fs may increase with rotational speed increasing and (4) the destruction and dechlorination are major mechanism for PCDD/Fs degradation. These results show that mechanochemical treatment is a high potential technology for PCDD/Fs degradation in fly ash.

P13 of Leucania separata multiple nuclear polyhedrosis virus affected the polyhedra and budded virions yields of AcMNPV

p13 gene was first described by our laboratory in Leucania separata multiple nuclear polyhedrovirus (Ls-p13, ORF114) back to 1995. However, the functions of Ls-P13 and its reported homologues remained unknown. In order to probe the function of Ls-P13, recombinant Autographa californica nucleopolyhedroviruses (rAcMNPVs) were constructed to express Ls-P13 in the Sf9 cells at early, late or early/late phase. Observations of microscope showed that the expression of Ls-P13 could decrease the yield of AcMNPV polyhedra in Sf9 cells, and early expressed Ls-P13 had stronger inhibition efficiency than that of the late expressed. Results of flow cytometry also indicated that Ls-P13 decreased the yield of AcMNPV polyhedra while increased those of budded virions (BVs) in Sf9 cells, but the efficacy was lost when its leucine zipper-like domain was mutated. Ls-P13 is a transmembrane protein, which was early located in the nucleus and late mainly in the cytoplasm membrane at 48 h. When its transmembrane domains were deleted, Ls-P13 distribution was dramatically diverted from cytoplasm membrane to nucleus, its corresponding efficacy on polyhedra yield was further increased while that on BVs was slightly weakened. Bioassay results indicated that Ls-P13 accelerated the larvae-killing rate. The mechanism might be that Ls-P13 increased BV yield.

Micro-reactors for PET tracer labeling

Miniaturization of PET radiosynthesis devices (micro-reactors or microfluidic systems) is an emerging area that has the potential to deliver many advantages, such as more efficient use of hot-cell space for production of multiple radiotracers; use of less non-radioactive precursor for saving precious material and a reduced separation challenge; highly controlled, reproducible and reliable radiotracer production; and cheap, interchangeable, disposable and quality-assured radiochemistry processors. Several 'proof of principle' examples along with basics of micro-reactor flow control, mixing principle and design, and device fabrication are discussed in this chapter.

Induction and inhibition of cytochrome P450-dependent monooxygenases of rats by fungicide bitertanol

The effects of fungicide bitertanol on cytochrome P450-dependent monooxygenases were studied using rats treated intraperitoneally with the N-substituted triazole for 4 days. Treatment with 10, 25, and 100 mg/kg bitertanol produced 2-, 4-, and 14-fold increases of 7-ethoxyresorufin O-deethylation activity in liver microsomes, respectively. Immunoblot analysis of microsomal proteins revealed that 25 mg/kg bitertanol increased CYP1A1 protein in the liver, kidney, and lung by 10-, 13-, and 17-fold, respectively. Bitertanol produced smaller increases of CYP2B and CYP3A catalytic activity and protein than that of CYP1A1 in liver. RT-PCR analysis of total RNA indicated that bitertanol-induced CYP1A1, CYP2B, and CYP3A mRNA. Additions of 0.01-100 microM bitertanol to liver microsomes from rats treated with 25 mg/kg bitertanol or 3-methylcholanthrene inhibited microsomal 7-ethoxyresorufin O-deethylation activity (IC(50)=0.8 or 0.9 microM). Bitertanol at 100 mg/kg increased liver UDP-glucuronosyltransferase and glutathione S-transferase activities by 2-fold. Bitertanol at 25 mg/kg produced a minor increase in metabolic activation of benzo[a]pyrene by liver S-9 fraction in the Ames mutagenicity test while the increase was blocked by addition of 100 microM bitertanol. These findings show that bitertanol is an inducer of CYP1A1, CYP2B, and CYP3A in vivo and an inhibitor of CYP1A catalytic activity in vitro.

Evaluation of PCDD/Fs emission from fluidized bed incinerators co-firing MSW with coal in China

The levels and homologue profile of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from stack gas of three typical fluidized bed incinerators co-firing municipal solid waste (MSW) with Chinese coal were measured. The PCDD/Fs emission was in the range of 0.0054-0.1961 ng I-TEQ/N m(3). Comparison of PCDD/Fs detection results by HRGC/HRMS and HRGC/LRMS suggested that it was feasible to detect fly ash with high PCDD/Fs concentration by HRGC/LRMS. Several factors on PCDD/Fs emission were discussed. The primary reason for the lower PCDD/Fs emission was the inhibition mechanism of relatively high sulfur in feeding coal on PCDD/Fs formation. The emission results also showed that there was no directly correlation between PCDD/Fs levels and CO, O(2) and HCl concentration in flue gas. It was estimated that about 0.1034 g I-TEQ was annually emitted to atmosphere from the tested three MSW incinerators (total daily treatment capacity is 800 tonnes MSW).

[Simultaneous determination of trace arsenic and antimony in textile by intermittent flow-hydride generation-atomic fluorescence spectrometry with L-cysteine as a prereducer]

A method for the simultaneous determination of trace arsenic and antimony in textile by intermittent flow-hydride generation-atomic fluorescence spectrometry with L-cysteine as a prereducer was developed. The optimal instrument condition was established. The influence factors such as the acidity of sample solution and carrier liquid, the concentrations of KBH4 and L-cysteine, the flow rate of carrier, and the interference of coexistent elements were investigated. The method was convenient and rapid. Under the optimal condition, the detection limits were 0.35 and 0.22 microg x L(-1), the relative standard deviations were 1.3% and 2.8%, and the recoveries were in the ranges of 93.6% - 98.4% and 92.2% - 103.6% for As and Sb respectively.

Treatment of Short Gut Syndrome With Early Living Related Small Bowel Transplantation

AIM

To investigate the results of treating short bowel syndrome with an early living related small bowel transplantation (SBT).

METHODS

A 17-year-old boy with a 20-cm-long residual intestine due to necrotic volvulus received an early living related SBT from his mother. Donor-specific blood transfusion was performed for 8 weeks before transplantation, each time for 50 mL every week. Cytomegalovirus status in both donor and recipient was negative. A 160-cm distal ileal segment was removed from the donor. The graft ilecolic artery and vein were anastomosed to the recipient's infrarenal aorta and caval vein. The proximal end of the graft was anastomosed end-to-end to the residual recipient jejunum; the distal anastomosis, between the distal end of the graft and transverse colon. An ileostomy was also performed. Immunosuppression, infection prophylaxis, and antithrombotic and nutrition support were given postoperatively.

RESULTS

The donor had an uneventful recovery. No technical complications were observed. The recipient was alive and well at 31 weeks after the operation. No graft rejection or infection was observed. He was off TPN 8 weeks after the operation and took low-fat food. The D-xylose test in the recipient was almost normal.

CONCLUSIONS

Early living related small intestine transplantation is a good treatment for short bowel syndrome.

Endocrine-disrupting activity in carbendazim-induced reproductive and developmental toxicity in rats

This study was designed to investigate the endocrine-disrupting activity of carbendazim-induced reproductive and developmental toxicity in Sprague-Dawley rats treated orally with the fungicide. Cotreatment of male rats with 675 mg/kg carbendazim and 50 or 100 mg/kg flutamide, an androgen receptor antagonist, once daily for 28 d blocked decrease of testis weight induced by treatment with carbendazim alone. The cotreatment prevented losses of spermatozoa and cell morphology and decrease of sperm concentration induced by carbendazim. Premating treatment of male and female rats with 200 mg/kg carbendazim for 28 d produced androgenic effects including incomplete development of uterine horn, enlargement of uretha, absence of vagina, and induction of seminal vesicles in female offspring, without marked effects in male offspring. Premating treatment with 100mg/kg benomyl, the parent compound of carbendazim, resulted in incomplete development of uterine horn and absence of vagina in female offspring and produced testis and epidydimis atropy in male offspring. Treatment of male rats with 25, 50, 100, 200, 400, and 800 mg/kg carbendazim for 56 d produced dose-dependent increases of androgen receptor concentrations in testis and epididymis. Additions of 5, 50, and 500 microM carbendazim to testis extract from untreated rats replaced binding of [3H]-5 alpha-dihydrotestosterone to androgen receptor in a concentration-dependent manner. The present study demonstrates that reproductive toxicity induced by carbendazim is blocked by an androgen receptor antagonist in male rats and developmental toxicity of the fungicide shows androgenic properties in female offspring. These results suggest that androgen- and androgen receptor-dependent mechanisms are possibly involved in carbendazim-induced toxicity.

Structural genomics efforts at the Chinese Academy of Sciences and Peking University

Structural genomics efforts at the Chinese Academy of Sciences and Peking University are reported in this article. The major targets for the structural genomics project are targeted proteins expressed in human hematopoietic stem/progenitor cells, proteins related to blood diseases and other human proteins. Up to now 328 target genes have been constructed in expression vectors. Among them, more than 50% genes have been expressed in Escherichia coli, approximately 25% of the resulting proteins are soluble, and 35 proteins have been purified. Crystallization, data collection and structure determination are continuing. Experiences accumulated during this initial stage are useful for designing and applying high-throughput approaches in structural genomics.

Inhibition of the proliferation of smooth muscle cells from human coronary bypass vessels by vasonatrin peptide

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is known to be a key event in the development of atherosclerosis and restenosis. The present study examined the effect of a novel synthetic natriuretic peptide, vasonatrin peptide (VNP), on norepinephrine (NE)-induced proliferation of VSMCs from coronary bypass vessels. Human VSMCs were isolated from an internal mammary artery (IMA) and saphenous vein (SV) by explant culture and stimulated with NE. MTT assay and [3H] thymidine-incorporation were undertaken to analyze cell proliferation and radioimmunoassay was used to determine the level of intracellular cyclic 3',5'-guanosine monophosphate (cyclic GMP). NE (10(-8) - 10(-7) mol/l) had a mitogenic effect in human VSMCs from both SV and IMA. However, NE-stimulated proliferation of VSMCs from SV was greater than that from IMA. Furthermore, low concentration of NE (10(-10) mol/l) promoted cell growth in SV-derived cells but not in IMA-derived cells. VNP (10(-8) - 10(-6) mol/l) reduced NE-induced cell proliferation and increased intracellular cyclic GMP, which were abrogated by HS-142-1. In addition, the growth inhibition of VNP was mimicked by 8-bromo-cGMP. These results indicate that VNP has a significant inhibitory effect on NE-stimulated proliferation of human VSMCs from both IMA and SV, which is mediated by guanylate cyclase-linked receptors by increasing cyclic GMP.

Inhibition of the proliferation of smooth muscle cells from human coronary bypass vessels by vasonatrin peptide

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is known to be a key event in the development of atherosclerosis and restenosis. The present study examined the effect of a novel synthetic natriuretic peptide, vasonatrin peptide (VNP), on norepinephrine (NE)-induced proliferation of VSMCs from coronary bypass vessels. Human VSMCs were isolated from an internal mammary artery (IMA) and saphenous vein (SV) by explant culture and stimulated with NE. MTT assay and [3H] thymidine-incorporation were undertaken to analyze cell proliferation and radioimmunoassay was used to determine the level of intracellular cyclic 3’,5’-guanosine monophosphate (cyclic GMP). NE (10-8 - 10-7 mol/l) had a mitogenic effect in human VSMCs from both SV and IMA. However, NE-stimulated proliferation of VSMCs from SV was greater than that from IMA. Furthermore, low concentration of NE (10-10 mol/l) promoted cell growth in SV-derived cells but not in IMA-derived cells. VNP (10-8 - 10-6 mol/l) reduced NE-induced cell proliferation and increased intracellular cyclic GMP, which were abrogated by HS-142-1. In addition, the growth inhibition of VNP was mimicked by 8-bromo-cGMP. These results indicate that VNP has a significant inhibitory effect on NE-stimulated proliferation of human VSMCs from both IMA and SV, which is mediated by guanylate cyclase-linked receptors by increasing cyclic GMP.

Chloroplast DNA phylogeography of Cunninghamia konishii (Cupressaceae), an endemic conifer of Taiwan

In this study, we investigated the genetic structure and phylogeographic pattern of the genus Cunninghamia, a member of the Cupressaceae restricted to mainland China and Taiwan, based on sequences of the trnD-trnT noncoding spacer of the chloroplast DNA. Maternal inheritance of chloroplasts was determined experimentally. No paternal leakage was detected. Both parsimony and neighbor-joining analyses revealed the polyphyly of Cunninghamia konishii, populations of which were nested in clades of C. lanceolata from mainland China. The nucleotide diversity of chloroplast DNA sequences within C. konishii (0.0118) was higher than that between species (0.0104), which agrees with a previous allozyme investigation. Based on mutational differences between sequences, a minimum spanning network consisting of five clades was constructed. Significant genetic differentiation (phiST = 0.130, P < 0.001) was detected between the clades based on AMOVA analyses. We infer several possible refugia in the Yunnan, Zhejiang, and Guangdong provinces of south China, all located in the minimum network as interior nodes. We also infer possible migration routes of Cunninghamia populations. The phylogeographic pattern shown in the reconstructed network suggests that the present-day Cunninghamia populations in Taiwan were derived from six different sources in continental Asia via long-distance seed dispersal. A migrant-pool model explains the heterogeneous composition of the organelle DNA in Taiwan's populations and the low differentiation between populations of Taiwan and China (phiCT = 0.012, P = 0.454). In contrast with the genetic heterogeneity within geographic populations, many local populations have attained coalescence at the trnD-trnT alleles, which has led to significant differentiation at the population level.

Hair removal by long-pulse alexandrite laser in oriental patients

The laser depilation system, cleared by the Food and Drug Administration since 1995, is evolving rapidly. However, the parameters in the hair removal function of these devices emphasize use for white people with fair skin (Fitzpatrick types I, II, or III). The characteristics of oriental skin and hair are black, coarse hairs in darker skin (Fitzpatrick types IV or V). As seen, the higher the skin melanin content, the more difficult to remove hair by laser. The authors report 146 oriental patients (156 body sites) who underwent treatment with the long-pulse alexandrite laser (wavelength, 755 nm) depilation system since November 1997. Percentage of hair removal (clearance rate) was assessed, and the histological change from laser pulse damage was observed. After two treatments, the clearance rates in the axillae and the leg were 61% and 62% respectively in the 15 to 20-J group (N = 47), and were 66% and 67% respectively in 21 to 25-J group (N = 64). After five treatments, 59 patients (37 axillae and 22 legs, all of which received 21-25 J per square centimeter of laser energy treatment during the course) had an average clearance rate of 91% (axillae) and 86% (leg), and the clearance rates have been maintained near 90% after long-term follow-up (average follow-up, 17 months). Minimal and transient complications are noted. In conclusion, using a combination of longer wavelength (but still in the optimal window of 630-870 nm), long pulse duration (10-40 msec), high fluence (but limited up to 25 J per square centimeter), multiple treatments, and concomitant direct cooling applied to the skin of oriental patients (Fitzpatrick types IV and V) with black, moderately coarse hair shafts achieves satisfying long-term hair removal results.

[Vasonatrin peptide attenuates hypoxia-induced increase in [Ca(2+)] (i) of culured rat cardiac fibroblasts]

The purpose of this work was to test the hypothesis that vasonatrin peptide (VNP) can attenuate the growth-promoting effect by hypoxia in cardiac fibroblasts of cultured neonatal rats. Cultured fibroblasts were divided into four groups: control group, hypoxia group, VNP group and VNP+hypoxia group. The growth of cardiac fibroblasts was observed using MTT method and the incorporation of (3)H-TdR, and the effect of VNP on the intracellular level of Ca(2+) was measured by means of interactive laser cytometry. It was found that hypoxia (2% - 3%) increased significantly the MTT optical density (OD) of cardiac fibroblasts (P<0.05 vs control group), but the increase was greatly attenuated in the VNP (10(- 6)mol/L) group and also the incorporation of (3)H-TdR in cardiac fibroblasts (P<0.05 vs hypoxia group). VNP (10(- 6)mol/L) also decreased the intracellular level of Ca(2+) which was increased by hypoxia (P<0.05) as compared with control and hypoxia group. These findings demonstrate that VNP can attenuate the hypoxia-induced growth-promoting effect in cardiac fibroblasts, which may be associated with the elevation of intracellular Ca(2+).

Effects of fluoride chewing gum on stimulated salivary flow rate and fluoride content

BACKGROUND

The purposes of this study were to measure the stimulated salivary flow rates generated by sorbitol gum, fluoride gum and paraffin wax control, and to assess the salivary fluoride clearance pattern in fluoride chewing gum.

METHOD

Six healthy subjects were instructed to chew paraffin wax control and sorbitol gum and fluoride gum (0.1 mg F/stick) 5 times per day for the experimental periods--21 days. Stimulated saliva samples were collected for each subject at 7, 14, 21 days at 3 pm after chewing of the gum. The saliva was collected at 1, 3, 5, and 8 minutes after the subject started chewing the wax or gum. Flow rates for each group and salivary fluoride content of the fluoride chewing gum were measured.

RESULTS

The overall mean salivary flow rates for the control, sorbitol gum and fluoride gum were 1.7 +/- 0.6, 2.0 +/- 0.6, and 2.1 +/- 0.7 ml/min respectively. The mean stimulated flow rate for fluoride gum was found significantly higher than that of the control (p = 0.002). However, no significant differences appeared between the control and sorbitol gum (p = 0.104), and sorbitol gum and fluoride gum (p = 0.563). The mean fluoride concentrations at different intervals during eight minutes of chewing fluoride gum were between 1.8 and 4.2 ppm.

CONCLUSION

Chewing fluoride-containing chewing gum releases fluoride at a low concentration in saliva. Fluoride chewing gum combining a salivary stimulator and caries prevention agent is a perspective method of caries prevention.

Tin-mesoporphyrin, a potent heme oxygenase inhibitor, for treatment of intracerebral hemorrhage: in vivo and in vitro studies

Spontaneous intracerebral hemorrhage (ICH) is the stroke subtype with highest mortality and morbidity. ICH can also occur following traumatic brain injury and thrombolysis for ischemic stroke and myocardial infarction. Development of ICH-induced hemispheric edema can elevate intracranial pressure and cause death. In survivors, edema-related white matter injury can lead to life-long neurological deficits. At present, there are no scientifically proven treatments for ICH. Heme oxygenase products, particularly iron and bilirubin, can be toxic to cells. In cerebral ischemia models, metalloporphyrins that are potent heme oxygenase inhibitors, reduce edema and infarct size. Tin-mesoporphyrin (SnMP) is a neuroprotectant that has also been used clinically to treat hyperbilirubinemia. Presently, we tested the hypothesis that SnMP treatment would reduce edema development following experimental ICH. We produced hematomas in pentobarbital-anesthetized pigs (9-11 kg) by infusing autologous blood into the frontal white matter. To maximize tissue concentrations, SnMP (87.5 microM in DMSO) or DMSO (vehicle controls) was included in the infused blood. Pig brains were frozen in situ at 24 hrs. following ICH and hematoma and edema volumes were determined on coronal sections by computer-assisted image analysis. We also examined the effects of SnMP in vitro on ferritin iron release, the formation of iron-induced thiobarbituric acid reactive substances (TBARS) and initial clot formation and hemolysis. SnMP treatment significantly reduced intracerebral mass following ICH. This was due to significant decreases in hematoma (0.68+/-0.08 vs. 1.39+/-0.30 cc, vehicle controls p<0.025) and edema volumes (edema = 1. 16+/-0.33 vs. 1.77+/-0.31 cc, p<0.05). In vitro, SnMP did not stabilize ferritin iron against reductive release nor did it decrease iron-induced TBARS formation in brain homogenates. SnMP or DMSO added to pig blood did not alter clot weights. In conclusion, SnMP reduced intracerebral mass in an ICH model by decreasing both hematoma and edema volumes SnMP's mechanism of action is presently unknown but may involve its potent inhibition of heme oxygenase activity. SnMP's effect appears unrelated to ferritin iron release, antioxidant activity or initial clot formation. Since SnMP treatment could be brain protective following ICH, further investigations into neurological and neuropathological outcomes and as well as into its mechanism of action are warranted.

Lethal midline granuloma: report of three cases

Lethal midline granuloma (LMG) is a rare clinical entity characterized by progressive relentless ulcerations and necrosis of midfacial structures. It occurs more frequently in Oriental than in Western populations with no demonstrable etiology. Treatment and outcome for cases differ, but their pathological distinction may not always be possible from routine biopsy specimens. The histological features often seen include widespread coagulative necrosis, heavy inflammatory infiltrates, and atypical pleomorphic cells. However, the paucity of these atypical cells in biopsy specimens and the degree of necrosis can make the diagnosis of a neoplastic lesion very difficult. Because of the progress in pathology methodology including immunohistochemistry, most cases have been proven to be malignant lymphomas of T-cell lineage. We present 3 patients for whom an initial clinical diagnosis of LMG was made. From their several oral biopsies and nasal specimens, difficulties were encountered in differentiating "midline granuloma" from other possible diseases using histomorphological criteria alone. After extensive evaluations, malignant T-cell lymphoma was the specific disease entity identified in only one case by cell membrane immunostaining technique. A literature review was carried out, and recent concepts of the etiology and pathogenesis of this disease are presented.

Glandular odontogenic cyst: a case report

Glandular odontogenic cyst (GOC) is an extremely rare lesion occurring in the jawbones. Sialo-odontogenic cyst was first described as a multicystic lesion resembling a botryoid odontogenic cyst (BOC) or a central mucoepidermoid carcinoma by Padayachee in 1987. In 1988, Gardner used the term "glandular odontogenic cyst" and considered it as a histologic variant of BOC. Most authors agreed that GOC was odontogenic because of the concurrent ball-like epithelial structure, ameloblastoma, squamous odontogenic tumor-like proliferation in its wall, or hyaline bodies in the epithelium lining. Recently, immunohistochemical studies of the cytokeratin profiles have also supported this concept. Its aggressive behavior and the recurrent tendency make it important. A new case of GOC in a 59-year-old male presented as a multilocular radiolucency in the anterior region of the mandible, invading the marrow space by epithelial islands is described with other clinicopathologic features and the literature is briefly discussed.

Adolescent females with a substance use disorder: affiliations with adult male sexual partners

OBJECTIVE

To test the hypothesis that low socioeconomic status (SES), a disturbed parent-daughter relationship, early sexual development, and antisocial behavior are risk factors in adolescent females affiliating with adult male sexual partners. To determine whether the relation between these risk factors and affiliating with adult male sexual partners is stronger in females with greater, rather than fewer, substance use disorders (SUD).

METHOD

Subjects were 180 adolescent females with SUD and 87 normal controls (14-18 years of age).

RESULTS

The SUD group had a lower SES and more negative parent-daughter interactions, and exhibited greater antisocial tendencies. Also, the SUD group showed a more frequent affiliation with adult male sexual partners. Chronological age, age of menarche (sexual development), antisocial behavior, and quality of the parent-daughter relationship were significantly associated with affiliation with adult male sexual partners. Moreover, the number of SUD diagnoses enhanced the relation between the quality of the parent-daughter relationship and antisocial behavior with affiliation with adult male sexual partners.

CONCLUSIONS

From a prevention perspective, interventions directed at enhancing child rearing practices, communication skills, and involvement in children's needs and activities might result in improved parent-child attachments that may attentuate young women's propensities to become involved in antisocial behavior and affiliate with adult sexual partners. Also, the risk imposed by an early sexual maturation may be offset by enhancing the female adolescent's social skills to select non-deviant and supportive male partners.

Dens invaginatus in the maxillary lateral incisor: treatment of 3 cases

Nonsurgical treatment of 3 maxillary lateral incisors with dens invaginatus is reported. Invaginated teeth present technical difficulties with respect to their management because of complicated canal morphology. In the first case reported, apical abscess with incomplete root formation was found at the time of examination. Calcium hydroxide apexification provided favorable conditions for root closure and obturation. The other 2 cases were treated by conventional root canal treatment. Follow-up examinations showed successful clinical results, with osseous healing evident radiographically.