Modification of cardiovascular responses to adenosine A1 receptor stimulation in the posterior hypothalamus of anaesthetized rats by cAMP and by GABA(B) receptor blockade

1 Injection of N(6)-cyclohexyladenosine (CHA; 1, 5 and 10 nmol), an adenosine A1 receptor agonist, into the posterior hypothalamus of rats produced a dose-dependent decrease in blood pressure (BP) and heart rate (HR). 2 Pretreatment with 8-cyclopentyl-1,3-dimethylxanthine (CPDX; 50 nmol), an adenosine A1 receptor antagonist, blocked the depressor and bradycardic effects of CHA (10 nmol). 3 Pretreatment with 8-bromo-cyclic adenosine monophosphate (AMP) (10 nmol), a cAMP analogue, attenuated the depressor and bradycardic effect of CHA (10 nmol); 8-bromo-cyclic guanosine monophosphate (GMP) (10 nmol), a cGMP analogue, did not modify those effects of CHA. 4 In addition, pretreatment with 5-aminovaleric acid (25 nmol), a gamma-aminobutyric acid (GABA)(B) receptor antagonist, attenuated the depressor and bradycardic effects of CHA (10 nmol). 5 These results suggest that adenosine A1 receptors in the posterior hypothalamus have an inhibitory role in the central cardiovascular regulation and that these vasodepressive and bradycardic actions are modified by raised cAMP and by GABA(B) receptor inhibition.

Dynamic instability of strongly confined thin polymer films in spinodal dewetting

We present a general criterion for determining the dynamic instability of a thin polymer film that is strongly confined to a substrate. When such a polymer film is heated above its glass transition temperature, it dewets from the substrate by a spinodal dewetting scenario, in which the onset of the instability is governed by dispersion force and residual thermal stress. It turns out that the thermal stress plays an important role when there is a special interaction between a polymer and a substrate.

Structural effects of Ti underlayer on CoCrPt magnetic films

The effects of long-range and short-range orders of Ti underlayer thickness on the magnetic properties of sputtered Co72 Cr21 Pt7 films were investigated using synchrotron X-ray scattering and X-ray absorption near-edge structure spectroscopy. The results were consistent with that of magnetic measurements and X-ray photoelectron spectroscopy. For thin Ti underlayers (10 nm), the oxidation of Ti and significant mixing of other elements within this underlayer did not promote texture development, further resulting in poor texturing of magnetic films and undesirable magnetic properties. Increased crystallinity and texture of metallic Ti in thicker underlayers enhanced the magnetic peak alignment and its properties.

CYP21 mutations and congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder caused mainly by defects in the steroid 21-hydroxylase (CYP21) gene. More than 90% of CAH cases are caused by mutations of the CYP21 gene on chromosome 6p21.3. The wide range of CAH phenotypes is associated with multiple mutations known to affect 21-hydroxylase enzyme activity. To date, 56 different CYP21 mutations have been reported, mostly point mutations, but small deletions or insertions have been described too, as well as complete gene deletions. Fifteen mutations, constituting 90-95% of alleles, are derived from intergenic recombination of DNA sequences between the CYP21 gene and the highly homologous CYP21P pseudogene, while the remaining are spontaneous mutations. A reliable and accurate detection of CYP21 mutations is not only important for clinical diagnosis, but also for carrier detection as there is a high variability in the basal level of 17-hydroxyprogesterone between normal and heterozygous individuals. Several strategies based on polymerase chain reaction (PCR)-driven amplification with allele-specific oligonucleotides to the CYP21 gene have been developed. It has been demonstrated that one reaction for PCR amplification of the CYP21 gene and the chimeric CYP21P/CYP21 gene using mixed primers in combination with nested PCR and single-strand conformation polymorphism is considered highly efficient and accurate for molecular diagnosis of CAH due to 21-hydroxylase deficiency.

Increased expression and localization of a serine protease inhibitor, protease nexin-1 (PN-1), in the ovary and uterus during implantation in rat

Protease nexin-1 (PN-1) is a serine protease inhibitor (serpin) that inactivates several proteases, including thrombin, urokinase, plasminogen activators (PA), and plasmin. It also plays a role in regulating proteolytic activity generated by PA system. PN-1 is known to be involved in tissue remodeling, cellular invasiveness, matrix degradation, and tumor growth. However, the role of PN-1 in female reproductive tracts, such as the uterus, ovary, and oviduct, during pregnancy is not known. The present study was designed to investigate the changes of PN-1 mRNA level and localization in the tracts during implantation and early pregnancy by using reverse transcription (RT)-polymerase chain reaction (PCR) and in situ hybridization. We found that PN-1 mRNA levels were coordinately regulated during early pregnancy in a stage- and tissue-specific manner, such that an increased expression of PN-1 gene appeared at the time of the implantation period in the uterus and ovary. Both the uterus and ovary synthesized PN-1 mRNA and their maximal PN-1 expression occurred on Day 6.5 postcoitum (p.c.). On 13.5 days of pregnancy, PN-1 level was low in the uterus and ovary. On the other hand, PN-1 mRNA in the oviduct did not show after 6.5 days of pregnancy. It appears that PN-1 mRNA in the uterus and ovary was highly regulated during early pregnancy, which might have an important role in implantation of rat blastocysts. PN-1 was localized in endometrial stromal cells of the uterus and in granulosa cells of the unstimulated primary follicles in the ovary during periimplantation period. Also, PN-1 mRNA expression was higher at implantation period than that at nonimplantation period of pregnancy. In conclusion, PN-1 is expressed in female reproductive tracts and highly regulated during implantation and early pregnancy.

Recombinant expression of biologically active rat leptin in Escherichia coli

Leptin is a 16-kDa nonglycosylated hormone that is produced in mature adipocytes and which acts primarily in the hypothalamus to reduce food intake and body weight. While the rat is a representative laboratory animal model in obesity research, so far recombinant rat leptin was not available. In the present study, rat leptin was recombinantly expressed in Escherichia coli and purified in a bioactive form to provide a further tool for the analysis of leptin functions in rats. Leptin cDNA was cloned by RT-PCR from total RNA of SD rat adipocytes, and overexpression was achieved by subcloning the leptin cDNA into the pET-29a vector, which enabled the recombinant expression of rat leptin as an S-peptide-tagged fusion protein. Since the fusion proteins were expressed in inclusion bodies, after purification of the insoluble fraction, leptin proteins were refolded by sequential dialysis into physiological buffers. The biological activity of this recombinant protein was confirmed in proliferation assays using leptin-sensitive rat insulinoma cells as well as a newly developed leptin-sensitive luciferase assay system. The specific binding of the S-tagged leptin to leptin-receptor-expressing cells was further shown by flow cytometry using fluorescence-conjugated S-proteins.

RNA expression patterns change dramatically in human neutrophils exposed to bacteria

A comprehensive study of changes in messenger RNA (mRNA) levels in human neutrophils following exposure to bacteria is described. Within 2 hours there are dramatic changes in the levels of several hundred mRNAs including those for a variety of cytokines, receptors, apoptosis-regulating products, and membrane trafficking regulators. In addition, there are a large number of up-regulated mRNAs that appear to represent a common core of activation response genes that have been identified as early-response products to a variety of stimuli in a number of other cell types. The activation response of neutrophils to nonpathogenic bacteria is greatly altered by exposure to Yersinia pestis, which may be a major factor contributing to the virulence and rapid progression of plague. Several gene clusters were created based on the patterns of gene induction caused by different bacteria. These clusters were consistent with those found by a principal components analysis. A number of the changes could be interpreted in terms of neutrophil physiology and the known functions of the genes. These findings indicate that active regulation of gene expression plays a major role in the neutrophil contribution to the cellular inflammatory response. Interruption of these changes by pathogens, such as Y pestis, could be responsible, at least in part, for the failure to contain infections by highly virulent organisms.

Transplacental transfer and age-related levels of serum IgG antibodies to the capsular polysaccharides of Streptococcus pneumoniae types 14 and 19 in Korea

Little is known about the prevalence of naturally acquired IgG antibodies to the capsular polysaccharides of Streptococcus pneumoniae (pneumococcal IgG) in Korea. In the present study, we investigated transplacental transfer and age-related levels of pneumococcal IgG to provide background seroepidemiologic data for S. pneumoniae in Korea. One hundred thirty eight sera were assayed by ELISA for IgG to pneumococcal polysaccharide capsular serotypes 14 and 19, the predominant serotypes for under 15 yr of age in Korea. The subjects were divided into 7 subgroups according to age. The cord/maternal geometric mean titer of pneumococcal were 4.47+/-5.88/5.21 +/- 5.88 for serotype 14, and 4.68 +/- 5.55/6.55 +/- 6.92 for serotype 1 9 (mean +/- standard deviation, microg/mL). After birth, the geometric mean titers of pneumococcal IgG for serotypes 14 and 19 expressed in microg/mL were 1.18+/-2.12 and 1.41+/-2.17 in the 0-6 months group, 0.27+/-0.19 and 0.69+/-0.93 in 7-12 months, 0.21+/-0.22 and 0.64+/-1.32 in 1-2 yr, 0.69+/-0.78 and 2.65+/-2.46 in 3-6 yr, 2.52+/-2.72 and 8.29+/-4.24 in 7-10 yr, respectively. In conclusion, reduced transplacental transfer and very low serum concentrations of pneumococcal IgG may contribute to the susceptibility of neonates, infants, and young children to S. pneumoniae infection.

Guidewire-induced coronary artery perforation treated with transcatheter injection of polyvinyl alcohol form

We describe a first case of successful transcatheter management of guidewire-induced distal coronary artery perforation and impending cardiac tamponade, which developed during percutaneous coronary angioplasty, with transcatheter injection of polyvinyl alcohol form. This method may be an effective alternative in the management of distal coronary artery perforation requiring surgical repair.

Detection of pET-vector encoded, recombinant S-tagged proteins using the monoclonal antibody ATOM-2

The 15-meric S-tag is a truncated form of the S-peptide, which builds together with the 103 amino acid large S-protein the whole ribonuclease S-protein. Its small size and excessive solubility have made the S-tag an excellent fusion partner in the production of recombinant proteins, and a large variety of applications have been reported using the S-tag as a carrier. While S-tagged proteins were mostly detected and analyzed so far by use of their affinity to S-proteins, monoclonal antibodies (MAbs) for this tag have been not available. The generation of antibodies specific for S-tagged proteins is expected to broaden the range of applications of such S-tag fused recombinant proteins, and in this context, a novel MAb termed ATOM-2 was generated that specifically binds S-tagged proteins, which have been expressed using pET-vectors. Antigen specificity of ATOM-2 was confirmed in Western blot and enzyme-linked immunoadsorbent assay analysis, and using a series of amino acid deletion mutants, the binding epitope of ATOM-2 was precisely mapped. This showed that ATOM-2 recognizes the C-terminal part of the 15-meric S-tag in context with a few residues of vector encoded sequences. The core sequence for ATOM-2 binding epitope is "His-Met-Asp-Ser-Pro-Asp-Leu-Gly-Thr," which is present in all pET-expression vectors encoding S-tag fusion proteins. Because the ATOM-2 binding region does not overlap with the S-protein binding sequence, a convenient tool is provided for the simultaneous or alternative detection, purification, and analysis of recombinant S-tagged proteins to conventional S-proteins.

Endogenous glycosylphosphatidylinositol-specific phospholipase C releases renal dipeptidase from kidney proximal tubules in vitro

Spontaneous enzymic release of renal dipeptidase (RDPase; EC 3.4.13.19), a glycosylphosphatidylinositol (GPI)-linked ectoenzyme, was observed in vitro during incubation of porcine proximal tubules at 37 degrees C. Triton X-114 phase separation of the released RDPase showed that the majority of the enzyme activity partitioned into the aqueous phase, indicating its hydrophilic nature. Immunoblot analyses using an antibody against the cross-reacting determinant (CRD) inositol 1,2-cyclic monophosphate, the epitope formed by phospholipase C (PLC) cleavage of the GPI anchor on a protein, detected the released RDPase. Reprobing the immunoblot with an anti-RDPase serum showed the RDPase band co-migrating with the CRD band. The release of RDPase from the proximal tubules was a Ca(2+)-dependent process and had a pH optimum of 9.0. These results indicate that RDPase is released from the proximal tubules by the action of a distinct endogenous GPI-specific PLC.

Inhibition of fungal appressorium formation by pepper (Capsicum annuum) esterase

A pepper esterase gene (PepEST) that is highly expressed during an incompatible interaction between pepper (Capsicum annuum) and the anthracnose fungus Colletotrichum gloeosporioides has been previously cloned. Glutathione-S-transferase-tagged recombinant PepEST protein expressed in Escherichia coli showed substrate specificity for p-nitrophenyl esters. Inoculation of compatible unripe pepper fruits with C. gloeosporioides spores amended with the recombinant protein did not cause anthracnose symptoms on the fruit. The recombinant protein has no fungicidal activity, but it significantly inhibits appressorium formation of the anthracnose fungus in a dose-dependent manner. An esterase from porcine liver also inhibited appressorium formation, and the recombinant protein inhibited appressorium formation in the rice blast fungus, Magnaporthe grisea. Inhibition of appressorium formation in M. grisea by the recombinant protein was reversible by treatment with cyclic AMP (cAMP) or 1,16-hexadecanediol. The results suggest that the recombinant protein regulates appressorium formation by modulating the cAMP-dependent signaling pathway in this fungus. Taken together, the PepEST esterase activity can inhibit appressorium formation of C. gloeosporioides, which may result in protection of the unripe fruit against the fungus.

Integration of chemical and biological treatments for textile industry wastewater: a possible zero-discharge system

Theoretical and experimental studies have established that integrated treatment systems (mostly chemical and biological) for various industrial wastewaters can achieve better quality of treatment and can be cost-effective. In the present study, the objective is to minimize the use of process water in the textile industry by an economical recycle and reuse scheme. The textile wastewater was first characterized in terms of COD, BOD5, salinity and color. In order to recycle such wastewater, the contaminants should be mineralized and/or removed according to the reusable textile water quality standards. Typical results show that this is achievable. An economic analysis has been conducted on the proposed integrated system. The economic analysis shows that the integrated system is economically more attractive than any of the single treatment technologies for achieving the same target of treatment. The information presented in this paper provides a feasible option for the reduction of effluent discharges in the textile industry.

Wingless effects mesoderm patterning and ectoderm segmentation events via induction of its downstream target sloppy paired

Inactivation of either the secreted protein Wingless (Wg) or the forkhead domain transcription factor Sloppy Paired (Slp) has been shown to produce similar effects in the developing Drosophila embryo. In the ectoderm, both gene products are required for the formation of the segmental portions marked by naked cuticle. In the mesoderm, Wg and Slp activities are crucial for the suppression of bagpipe (bap), and hence visceral mesoderm formation, and the promotion of somatic muscle and heart formation within the anterior portion of each parasegment. In this report, we show that, during these developmental processes, wg and slp act in a common pathway in which slp serves as a direct target of Wg signals that mediates Wg effects in both germ layers. We present evidence that the induction of slp by Wg involves binding of the Wg effector Pangolin (Drosophila Lef-1/TCF) to multiple binding sites within a Wg-responsive enhancer that is located in 5′ flanking regions of the slp1 gene. Based upon our genetic and molecular analysis, we conclude that Wg signaling induces striped expression of Slp in the mesoderm. Mesodermal Slp is then sufficient to abrogate the induction of bagpipe by Dpp/Tinman, which explains the periodic arrangement of trunk visceral mesoderm primordia in wild type embryos. Conversely, mesodermal Slp is positively required, although not sufficient, for the specification of somatic muscle and heart progenitors. We propose that Wg-induced slp provides striped mesodermal domains with the competence to respond to subsequent slp-independent Wg signals that induce somatic muscle and heart progenitors. We also propose that in wg-expressing ectodermal cells, slp is an integral component in an autocrine feedback loop of Wg signaling.

Characterization of salt-tolerant mutant for enhancement of L-threonine production in Escherichia coli

Escherichia coli strain HS3, metabolically engineered to have Met(-), AHV(r), Ile(L) and AEC(r) characteristics, produced 58.0 g/l of L-threonine, but it was neither salt-tolerant nor osmotolerant; and the growth and threonine production of the strain were severely inhibited both by the addition of NaCl with a concentration higher than 2% and by the presence of glucose with a concentration higher than 10%. Therefore, salt-tolerant mutants were isolated. The salt-tolerant mutants, HS454 and HS528 which were derived from strain HS3, were both tolerant to salt (2%) and hyper-productive. The growth and L-threonine production by the mutant strain HS454 were almost unaffected by a glucose concentration lower than 10%, but gradually reduced with increasing glucose concentration, up to 15%. However, the mutant strain HS528 showed slightly enhanced growth and L-threonine production with increasing glucose concentration, up to 10-12.5%. Strains HS454 and HS528 produced 69.8 g/l and 74.0 g/l of L-threonine, respectively in a 5-1 jar fermentor.

Upregulation of Bcl-x and Bfl-1 as a potential mechanism of chemoresistance, which can be overcome by NF-kappaB inhibition

In A549 human lung adenocarcinoma cells, we found that TNF-alpha and several commonly used chemotherapeutic agents upregulated the expression of Bcl-x and/or Bfl-1/A1 through an NF-kappaB-dependent pathway. While parental A549 cells were resistant to the cytotoxic effects of both TNF-alpha and chemotherapy agents, NF-kappaB-blocked A549 cells were sensitized to both. Expression of either Bcl-x or Bfl-1/A1 in the NF-kappaB-deficient cells at physiological levels provided differential protection against TNF-alpha and chemotherapeutic treatment. These studies provide a potential mechanism for the phenomenon of chemotherapy-induced chemoresistance, and also reveal a potential strategy by which chemoresistance can be overcome.

A new method to control electrolytes pH by circulation system in electrokinetic soil remediation

To simultaneously avoid a decrease of electro-osmotic flow by hydrogen ions and to increase heavy metal precipitation due to hydroxide ions, simulated electrokinetic remediation was conducted in saturated kaolinite specimens loaded with lead(II) using an electrolyte circulation method to control electrolyte pH. At an electrolyte circulation rate of 1.1 ml/min, it was possible to increase the anolyte pH from 2 to 4 and decrease the catholyte pH from 12 to 8. Using electrolyte circulation, it was observed that the rate of decrease of clay pH due to the change of electrolyte pH was reduced. As a result, the operable period was extended and the removal efficiency for lead(II) was also increased. It was observed that most of the effluent lead(II) from the cathode compartment was electroplated onto the cathode and that residual effluent lead(II) did not precipitate onto, or adsorb to, the clay at the anode compartment during circulation. Therefore, there was no need to treat the electrolyte because there was virtually no effluent from the cathode compartment in the circulation system. It was also found that the electrolyte volume required to sustain the electrolytic reaction was sufficient for the whole electrokinetic remediation process.

BRCA1 mutations in Taiwanese with epithelial ovarian carcinoma and sporadic primary serous peritoneal carcinoma

BACKGROUND

Germline BRCA1 mutations of sporadic ovarian cancers are presumed to be rare events, except among specific populations. To date, the status of germline BRCA1 mutations in Taiwanese with primary epithelial ovarian carcinoma (PEOC) is still unknown. In this study, we tried to answer part of this question.

METHODS

Sixty-four patients documented with PEOC, four patients with family history of breast and/or ovary cancer syndrome and five patients with sporadic primary serous peritoneal carcinoma (PSPC) were enrolled in this retrospective study from January 1994 through June 1999. At the same time, 50 normal healthy Taiwanese without family history were enrolled in this study. Germline DNA from these patients was screened for mutations in the BRCA1 gene using polymerase chain reaction-based single-stranded conformation polymorphism analysis (PCR-SSCP). Shifting DNA bands were sequenced.

RESULTS

One of the 64 patients with PEOC (1.6%) exhibited germline BRCA1 heterozygous mutation which was exon11 single-base substitution at nucleotide1047 (CAG to TAG). One of the five patients with PSPC (20%) exhibited an exon11 single-base substitution at nucleotide 914 (TCT to TCC) with resultant silent mutation. One of the normal healthy Taiwanese (2%) was found to have an exon 2 single-base substitution at nucleotide 152 (A-->C) which was also a silent mutation. No mutations of BRCA1 were detected in four patients with a family history of breast and/or ovarian cancer.

CONCLUSIONS

Based on this study, it was very difficult to obtain precise data to prove the value of applying genetic testing of BRCA1 mutations in Taiwanese patients with sporadic epithelial ovarian cancers or sporadic PSPC and even with a family history of breast and/or ovarian cancer because of its rare event and because of the too small number of cases available in this study.

Use of TaqI digestion may lead to incorrect molecular diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. For reliable and accurate mutation detection in the CYP21 gene it is important to separate the CYP21 gene from the highly homologous CYP21P pseudogene. For this, several different strategies have been developed. In the analysis of the common eight nucleotide deletion at codon 110-112, a strategy using the TaqI restriction enzyme was first applied. In one family, the results showed discordance between parents and offspring. The use of microsatellite markers flanking the genuine CYP21 gene did not lead to a correct assignment. The problem was finally resolved by using differential PCR amplification for generating a CYP21-specific template. It was concluded that incomplete TaqI digestion, although not visible on an agarose gel, allowed the amplification of the CYP21P pseudogene, thus leading to a false positive diagnosis. Therefore, we recommend the use of direct gene-specific primers for the essential step in the molecular diagnosis of congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency.

Development of brain injury in mice by Angiostrongylus cantonensis infection is associated with the induction of transcription factor NF-kappaB, nuclear protooncogenes, and protein tyrosine phosphorylation

Eosinophilic meningitis or meningoencephalitis caused by Angiostrongylus cantonensis is endemic to the Pacific area of Asia, especially Taiwan, Thailand, and Japan. Although eosinophilia is an important clinical manifestation of A. cantonensis infection, the role of eosinophils in the progress of the infection remains to be elucidated. In this experiment, we showed that A. cantonensis-caused eosinoplia and inflammation might lead to the induction of NF-kappaB and protooncogene expression via activation of the tyrosine phosphorylation signal pathway. After mice were infected daily with 30 third-stage larvae of A. cantonensis by oral adminstration for 6 weeks, no significant differences PKC-alpha, MEK-1, ERK-2, JNK, and p38 protein expression were found between the control and infected mice. However, the protein tyrosine phosphorylation levels, NF-kappaB, and iNOS protein products were significantly increased by 3.5-, 3.3-, and 6.3-fold, respectively, after 3 weeks of A. cantonensis infection. The same pattern was found for c-Myc, c-Jun, and c-Fos proteins, which were elevated by 3.2-, 2.3-, and 3.4-fold, respectively, compared to control animals after 3 weeks. The expression potency of these proteins started increasing in week 1, reaching maximal induction in week 3, and then declining in week 5 after A. cantonensis infection. Another consistent result was noted in the pathological observations, including eosinophilia, leukocyte infiltration, granulomatous reactions, and time responses in brain tissues of infected mice. These data suggest that the development of brain injury by eosinophlia of A. cantonensis infection is associated with NF-kappaB and/or nuclear protooncogenes expression, which is activated by the tyrosine phosphorylation pathway.

Mutation analysis of the Bcl 10 gene in hepatocellular carcinoma

The Bcl 10 gene was recently discovered to be involved in the pathogenesis of lymphoma of mucosa-associated lymphoid tissue and several types of tumorous cell lines. We examined the mutation of Bcl 10 gene in 31 hepatocellular carcinomas along with their corresponding non-tumorous tissues by single strand conformation polymorphism (SSCP) and direct sequencing. The results showed that 11.3% chromosomes had codon 5 GCA to TCA mutation, 4.8% chromosomes had codon 8 CTC to CTG mutation, and 12.9% chromosomes had codon 213 GGA to GAA mutation. These mutations were found not only in the hepatoma tissues but also in paired non-cancerous tissues and the normal population. We suggest that these three changes are polymorphisms, and there is no relationship with the development of hepatocellular carcinoma.

Qualitative determination of urinary morphine by capillary zone electrophoresis and ion trap mass spectrometry

A rapid, sensitive method for the determination of morphine and amphetamine was developed using capillary zone electrophoresis coupled with electrospray interface (ESI), ion-trap tandem mass spectrometry (CE-ESI-MS2). Morphine and amphetamine were separated in 20 mM ammonium acetate buffer (pH 6.6) and detected by ion-trap mass detector in different analytical time segments (0-6.25 min for amphetamine and 6.25-12.0 min for morphine) in which the tune file for each compound was used separately. Molecular ions of morphine (m/z 286) and amphetamine (m/z 136) were detected at 5.77 and 6.83 min, respectively, while product ions of MS2 for each compound (m/z 229, 201 for morphine and m/z 119 for amphetamine) were detected almost exactly at the same time with their parent compounds. The limits of detection (LOD) for MS2 determination were 30 and 50 ng/mL for amphetamine and morphine, respectively, with an S/N ratio of 3. For more sensitive detection of morphine, the sample was injected for a longer time (i.e., 80 s) and hydrodynamically transported into a CE capillary for MS detection. Morphine and its product ion appear at 0.36 and 0.39 min on the ion chromatogram, respectively, with a five-fold increase of detection sensitivity (LOD, 10 ng/mL). The CE-MS system thus established was further applied for forensic urine samples screened as morphine-positive by fluorescence polarization immunoassay (FPIA). These results indicated the feasibility of CE-ESI-MS2 for confirmative testing of morphine in urine sample.

Analysis of the chimeric CYP21P/CYP21 gene in steroid 21-hydroxylase deficiency

BACKGROUND

A single nonfunctional chimeric gene with its 5' and 3' ends corresponding to CYP21P and CYP21, respectively, is caused by unequal gene crossover in the CYP21 genes during meiosis. The presence of the chimeric CYP21P/CYP21 molecule can not be detected by conventional PCR methods and therefore may be lost in PCR amplification. This leads to a false result and diagnostic discordance.

METHODS

We developed a rapid and direct method to detect a chimeric CYP21P/CYP21 gene that uses a 3'-specific primer for the CYP21 gene and two different 5' primers for both CYP21 and CYP21P to amplify the wild-type CYP21 and the chimeric CYP21P/CYP21 genes. A secondary PCR that can differentiate the chimeric from the wild-type gene was also performed. The PCR product was directly analyzed on agarose gel.

RESULTS

After careful titration, we found that earlier failure to detect the chimeric CYP21P/CYP21 gene could be caused by unequal concentrations of two independent alleles as the PCR template or by the lack of primers to amplify chimeric molecules. We successfully amplified the chimeric gene using our improved method.

CONCLUSIONS

The chimeric CYP21P/CYP21 is present in a large portion of congenital adrenal hyperplasia patients. By adding a CYP21P/CYP21-specific primer, we were able to amplify and detect both homozygous and heterozygous chimeric genes. Therefore, our new PCR-based assay is a more effective way to analyze congenital adrenal hyperplasia mutations.

Analysis of an SMN gene-like DNA fragment

Part of a survival motor neuron (SMN) gene-like DNA fragment has been identified. This DNA fragment was accidentally isolated from cDNA by RT-PCR using primers specific for the region between exon 3 and 6 of the SMN gene. This fragment was used as a probe to hybridize the mRNA from several tissues, but we have been unable to detect any transcript of this SMN-like gene in these tissues. Thus, we have inferred this SMN gene-like fragment was a genomic product contaminant that was amplified in the reaction. Sequencing analysis of this fragment, which contains several stop codons, revealed a 74.6% nucleotide homology with the SMN gene. From these results, we believe that this DNA fragment is not a mutated form of SMN gene. Rather, it is an SMN-like pseudogene, which is variably present even in normal individuals.

Rapid identification of the ABO genotypes by their single-stand conformation polymorphism

The ABO locus on chromosome 9 contains many more alleles than are currently used routinely in forensic science. The use of single-strand conformation polymorphism (SSCP) can separate sequence polymorphisms that differ by only one base. The SSCP process used allows for both single- and double-stranded polymerase chain reaction (PCR) products to be visualized. The six ABO genotypes can be differentiated by the allele-specific B and O SSCP patterns. The double-stranded DNA produced 'hybrid' bands due to heterozygous samples and allowed sequence diversity to be detected between alleles of heterozygotes. These 'hybrid' bands are valid markers to confirm genotypes of specimens.

Carrier analysis and prenatal diagnosis of congenital adrenal hyperplasia caused by 21-hydroxylase deficiency in Chinese

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. We screened 1,000 healthy people, using a previously developed differential PCR method combined with single-strand conformation polymorphism and amplification-created restriction site methods for the carrier detection of the CYP21 gene deficiency. Our results indicated that the rate of occurrence of the heterozygous CAH carrier was about 12 in 1,000, with a gene frequency of 0.0060 and an incidence frequency of 1 in 28,000 in the Chinese population. In addition, 9 cases of CAH families were performed with prenatal diagnosis. Among them, 3 cases were diagnosed as the severe form, 4 cases carried the heterozygous mutation, and 2 were normal. This is the first report of carrier frequency analysis and prenatal diagnosis of 21-hydroxylase deficiency in Chinese.

Effect of die relief on the seating, fit and retention of cast gold crowns cemented on human teeth

Die relief, by means of a paint-on die spacing material, is the most common method of achieving sufficient space between metal castings and tooth surfaces for cement to flow during seating. Several studies have determined the influence of cementing variables on crowns made for metal and plastic test dies. This study assessed the influence of die relief upon the seating and retention of cast gold crowns constructed for natural human teeth. Standard full crown preparations were made for 10 matched pairs of extracted human third molars, one each of which had been relieved with die spacer of approximately 40 microns thickness. Crowns were made by the indirect technique and were cemented with zinc phosphate cement in a static/dynamic jig. Seating behaviour and vertical discrepancies were measured electronically. Tensile bond strengths were determined in a universal testing machine. Results showed that die relief reduced vertical seating discrepancy associated with cementation by up to 79 microns. Differences between paired relieved and unrelieved samples were significant (p < 0.05). There were no statistically significant differences in tensile bond between paired relieved and unrelieved crowns.

Molecular analysis of Duffy, Yt and Colton blood groups in Taiwanese, Filipinos and Thais

We used a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for DNA-based typing of Duffy, Yt and Colton blood groups in Taiwanese, Filipinos and Thais. A total of 200 Taiwanese, 115 Filipinos and 105 Thais were studied. In the Duffy blood group in Taiwanese, 180 cases (90%) were homozygote of Fya, 18 cases (9%) were double heterozygote of Fya and Fyb, and 2 cases (1%) were homozygote of Fyb. In Filipinos, 98 cases (85.2%) were homozygote of Fya, 16 cases (14.0%) were double heterozygote of Fya and Fyb and 1 case (0.8%) was homozygote of Fyb. In Thais, 87 cases (82.9%) were homozygote of Fya, 18 cases (17.1%) were double heterozygote of Fya and Fyb, and no case of Fyb was found. These results correlate well with serological phenotype. For the Yt blood group, only YT1 was found in Taiwanese. Among Filipinos, 114/115 (99.1%) was YT1/1 and 1/115 (0.9%) was YT1/2. In Thais, 103/105 (98.1%) was YT1/1 and 2/105 (1.9%) was YT1/2. For the Colton blood group, the results showed that there was only Coa allele in these three populations. Our results provide the first data of the Yt and Colton blood groups in these three populations.

Nitracrine N-oxides: effects of variations in the nature of the side chain N-oxide on hypoxia-selective cytotoxicity

The tertiary amine N-oxide (nitracrine-N-oxide, 1b) of the 1-nitroacridine nitracrine is a bis-bioreductive agent showing very high hypoxic selectivity (approximately 1000-fold) against tumour cells in culture, but only modest activity against the hypoxic subfraction of tumours in vivo. Because the hypoxic selectivity of 1b was considered to depend significantly on the rate of enzyme-mediated reduction of the N-oxide group, this paper reports the preparation and evaluation of a series of analogues in which the environment of this group was modified. Three analogues contained more weakly basic N-oxides, while two others had varying degrees of steric bulk around the N-oxide. In all but one case (an aromatic N-oxide), the N-oxides were much less cytotoxic (10- to 300-fold) than the corresponding tertiary amines towards AA8 Chinese hamster cells under aerobic conditions. Both the N-oxides and the corresponding amines were more cytotoxic to an ERCC-1 mutant defective in nucleotide excision repair, indicating that DNA alkylation was the cytotoxic event. However, there was no apparent correlation of these parameters with structure. All of the aliphatic N-oxides, with the exception of the aromatic N-oxide example, showed substantial (70- to 800-fold) hypoxic selectivity against AA8 cells in a clonogenic assay. While the weakly basic derivatives were the least selective, there was no apparent relationship between hypoxic selectivity and the steric environment of the N-oxide. Selectivity for hypoxic cells in culture is shown to depend on the hypoxic selectivity of the corresponding tertiary amine (reflecting O2-inhibitable reduction of the 1-nitro group) and the differential in aerobic toxicity between amine and N-oxide (a measure of the potential toxicity increase achievable by reducing the N-oxide). Four analogues whose structures fairly represented the range of steric and electronic modifications of the N-oxide site were evaluated against the hypoxic subfraction of cells in KHT tumours in vivo, but were inactive. These results suggest that either such modifications do not exert significant effects on N-oxide reduction, or that the rate of such reduction is not a factor limiting the in vivo activity of the parent analogue 1b.

Fracture toughness and durability of chemically or thermally tempered metal-ceramic porcelain

Thermocycling and water storage effects on fracture toughness (KIC) of chemically or thermally tempered metal-ceramic disks were investigated to evaluate the durability of tempering effects with regard to oral aqueous environment. Metal-ceramic disks (phi 10 mm x 2.0 mm) consisting of opaque porcelain (0.2 mm thick), body porcelain (1.3 mm) and Ni-Cr-Be alloy (0.5 mm) were prepared and the porcelain surfaces were polished with 1-micron diamond paste. The disks were subjected to ion exchange (potassium or rubidium) or thermal tempering treatments, then with the as-polished or further annealed disks, thermocycled for 8000, 15,000, and 22,000 cycles between 5 degrees C and 60 degrees C or stored in water at 37 degrees C for 33 days. After aging, KIC values of disks were determined by a Vickers indentation technique. Statistical analyses indicated that the KIC values of ion-exchanged and annealed disks were not significantly affected by the limited number of cycles and water storage, while the thermally tempered and untreated disks revealed a significant decrease in mean KIC from even 8000 cycles and after storage. However, there was no significant difference between thermocycling and water-storage effects on mean KIC of all surface treatment groups. Results indicate that chemical tempering (ion exchange) produced more durable residual stresses than does thermal tempering for metal-ceramic restorations. A low-thermal load only was unlikely to affect the apparent fracture toughness of porcelain.

NF-kappa B-dependent Fas ligand expression

Apoptosis of lymphocytes is triggered by different stimuli through the induced expression of Fas and Fas ligand (FasL). Using T cell activation-induced Fas/FasL expression as a model system, we observed a differential regulation of the induction of Fas and FasL. cAMP inhibited activation-induced apoptosis by an effective suppression of TCR-coupled FasL expres sion. In contrast, cAMP weakly interfered with activation-induced Fas expression, and the remaining Fas molecules on cAMP-treated T cells still mediated apoptosis. Among the major transcription elements on the FasL promoter, the activation of NF-kappaB, but not of NF-AT and AP-1, was suppressed by cAMP. The prominent role of NF-kappaB was further demonstrated by a better activation of the FasL promoter and an elevated expression of FasL induced by p65 (RelA) overexpression than those induced by AP-1 or NF-AT. Our results demonstrate the essential role of NF-kappaB for the expression of the death receptor ligand FasL, and suggest a direct link between NF-kappaB activation and the expression of FasL. NF-kappaB may be the common mediator in the induction of FasL through TCR activation and by various stress stimuli.

NF-kappaB-mediated up-regulation of Bcl-x and Bfl-1/A1 is required for CD40 survival signaling in B lymphocytes

Activation of CD40 is essential for thymus-dependent humoral immune responses and rescuing B cells from apoptosis. Many of the effects of CD40 are believed to be achieved through altered gene expression. In addition to Bcl-x, a known CD40-regulated antiapoptotic molecule, we identified a related antiapoptotic molecule, A1/Bfl-1, as a CD40-inducible gene. Inhibition of the NF-kappaB pathway by overexpression of a dominant-active inhibitor of NF-kappaB abolished CD40-induced up-regulation of both the Bfl-1 and Bcl-x genes and also eliminated the ability of CD40 to rescue Fas-induced cell death. Within the upstream promoter region of Bcl-x, a potential NF-kappaB-binding sequence was found to support NF-kappaB-dependent transcriptional activation. Furthermore, expression of physiological levels of Bcl-x protected B cells from Fas-mediated apoptosis in the absence of NF-kappaB signaling. Thus, our results suggest that CD40-mediated cell survival proceeds through NF-kappaB-dependent up-regulation of Bcl-2 family members.

Pediatric genitourinary tumors

Advances in our knowledge of pediatric genitourinary tumors are being made at a rapid pace at both the basic science and clinical levels. As the molecular mechanisms underlying these malignancies are being uncovered, treatment options are being modified to decrease morbidity and, ultimately, increase survival. This article reviews the recent literature on Wilms' tumor, rhabdomyosarcoma, and testicular tumors.

Neoadjuvant hormonal therapy in carcinoma of the prostate

The rising incidence of and mortality from prostate cancer has generated great interest in improving the results of current methods of treatment. It is well-established that large tumour volumes and positive surgical margins are correlated with higher rates of local failure and distant metastasis. Significant decreases in both tumour volume and the rates of positive surgical margins are seen with NHT. Follow-up data from one randomized trial of hormonal therapy before RT have shown significantly improved disease-free survival, but so far there has been no benefit in overall survival. However, the addition of adjuvant hormonal therapy has been reported to improve survival. The results suggest that neoadjuvant and adjuvant hormonal therapy may be a viable option in men with locally advanced prostate cancer in whom cure is probably impossible, but disease progression can potentially be slowed. What remains to be determined is whether hormonal therapy alone can produce the same results. For younger men with clinically localized prostate cancer, radical prostatectomy is increasingly the treatment of choice. Prospective randomized trials of NHT have produced impressive statistics for decreasing the incidence of positive surgical margins, but the potential to down-stage tumours remains controversial. Follow-up serum PSA measurements have thus far shown no benefit from neoadjuvant therapy. The possibility that patients who fail biochemically, whether they are from the pretreated or control group, may simply represent a subgroup with aggressive tumours that may not respond to androgen withdrawal, has yet to be proved. As more follow-up data are analysed within the next several years, there must be a clear survival advantage if NHT is to be offered as a treatment option. Despite the potential of neoadjuvant therapy, the use of androgen withdrawal before definitive surgical treatment should be limited to clinical trials until a clearer picture emerges. Some may argue that although there is no evidence of a true advantage for NHT, neither is there evidence of harm. However, it must be recognized that androgen withdrawal therapy has side-effects and adds significantly to the overall cost of treatment. Furthermore, NHT delays definitive treatment; clearly, this can be a source of anxiety for the patient and the impact on survival is unknown. Currently, the rates of pathologically organ-confined disease are high in some subsets of patients (e.g. low-stage, low-grade and low PSA) so that NHT is unlikely to have great additional benefit. Although the influence of hormones on prostate growth has been known for many decades, we are only now elucidating the biological mechanisms of hormonal therapy. Although androgen ablation therapy has been used in men with metastatic prostate cancer for more than 50 years, further research at the cellular and molecular level is essential if we are to refine treatment modalities for both localized and advanced disease. Furthermore, until we have more follow-up data from randomized clinical trials of NHT, it cannot be considered part of the standard treatment for carcinoma of the prostate. There are still too many unknown factors; only time will tell if the initial promise of NHT will be fulfilled.

Specificities of CD40 signaling: involvement of TRAF2 in CD40-induced NF-kappaB activation and intercellular adhesion molecule-1 up-regulation

Several tumor necrosis factor receptor-associated factor (TRAF) family proteins including TRAF2, TRAF3, TRAF5, and TRAF6, as well as Jak3, have been implicated as potential mediators of CD40 signaling. An extensive in vitro binding study indicated that TRAF2 and TRAF3 bind to the CD40 cytoplasmic tail (CD40ct) with much higher affinity than TRAF5 and TRAF6 and that TRAF2 and TRAF3 bind to different residues of the CD40ct. Using CD40 mutants incapable of binding TRAF2, TRAF3, or Jak3, we found that the TRAF2-binding site of the CD40ct is critical for NF-kappaB and stress-activated protein kinase activation, as well as the up-regulation of the intercellular adhesion molecule-1 (ICAM-1) gene, whereas binding of TRAF3 and Jak3 is dispensable for all of these functions. Overexpression of a dominantly active IkappaBalpha strongly inhibited CD40-induced NF-kappaB activation, ICAM-1 promoter activity, and cell-surface ICAM-1 up-regulation. These studies suggest a potential signal transduction pathway from the CD40 receptor to the transcriptional activation of the ICAM-1 gene.

Vezf1: A Zn finger transcription factor restricted to endothelial cells and their precursors

Using retroviral entrapment vectors, we identified a novel mouse gene whose expression is restricted to vascular endothelial cells and their precursors in the yolk sac blood islands. A 3.68-kb cDNA corresponding to the endogenous transcript was isolated using genomic DNA flanking the entrapment vector insertion as a probe. We have named this gene Vezf1 for vascular endothelial zinc finger 1. Vezf1 encodes a protein with a predicted molecular mass of 56 kDa and that contains six putative zinc finger domains and shows high homology to a previously identified human gene, DB1, that is believed to be involved in regulating expression of cytokine genes such as interleukin-3. In situ hybridization analysis revealed the onset of expression in advanced primitive streak-stage embryos being located in the extraembryonic mesodermal component of the visceral yolk sac and in the anteriormost mesoderm of the embryo proper. During head-fold and somite stages, expression was restricted to vascular endothelial cells that arise during both vasculogenesis and angiogenesis. Vezf1-related sequences were found to be highly conserved among higher vertebrate species that have acquired extraembryonic yolk sac membranes during evolution. The Vezf1 locus mapped to the proximal part of mouse chromosome 2, a region which has homology to human chromosome 9q. Vezf1 expression correlates temporally and spatially with the early differentiation of angioblasts into the endothelial cell lineage and the proliferation of endothelial cells of the embryonic vascular system. Thus, Vezf1 may play an important role in the endothelial lineage determination and may have an additional role during later stages of embryonic vasculogenesis and angiogenesis.

Development of calcium phosphate cement for rapid crystallization to apatite

The purpose of this study was to develop an alpha-tricalcium phosphate (alpha-TCP) cement which transforms to hydroxyapatite (HAP) in a relatively short period. We used calcium and phosphate solutions as the liquid phase for the alpha-TCP cement. The alpha-TCP powder was first mixed with CaCl2 solution, and then mixed with NaH2PO4 or Na2HPO3 solution for a total powder/liquid ratio of 1.8. The setting time became shorter with the increase in the concentration of calcium and phosphate solutions, reaching 5 min, whereas the setting time was longer than 30 min when distilled water was used as the liquid phase. X-ray diffraction analysis revealed that the cement was mostly transformed to HAP within 24 h when kept in an incubator. We concluded that alpha-TCP should be mixed with calcium and phosphate solutions since this results in a moderate setting time and fast transformation to HAP even if the method of mixing becomes a little complex.

Identification of four novel mutations in the CYP21 gene in congenital adrenal hyperplasia in the Chinese

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. We have analyzed CYP21 gene sequences in 65 CAH families in Taiwan. All ten exons of the CYP21 gene were analyzed by differential polymerase chain reaction followed by single-strand conformation polymorphism electrophoresis and the amplification-created restriction site method. About 95% (123 chromosomes) contain mutations due to conversion of DNA sequences into its neighboring homologous pseudogene, CYP21P. Four novel mutations representing 5% of the total chromosomes have also been identified. The mutations were confirmed by sequencing an aberrant DNA fragment. These four mutations included a base change of the splicing donor site at intron 2 from GT to AT, a base substitution of C to T at codon 316, deletion of ten bases (TCCAGCTCCC) at codons 330-333 of exon 8, and duplication of 16 bases (CCTGGATGACACGGTC) at codons 393-397 of exon 9. The loss of the splicing donor site at intron 2 and the premature stop at codon 316 may result in aberrant splicing to reduce enzyme activity and a truncated protein with no enzyme activity, respectively. Likewise, both the duplication and the deletion forms create a frameshift and premature stop during translation. The resulting proteins lack the heme-binding domain and hence are expected to lose enzymatic activity. Since these mutations are not found in the neighboring CYP21P pseudogene, gene conversion should not be the cause of these novel mutations.

In vitro effects of various neuropharmacological agents on the motility of adult Clonorchis sinensis

Stimulatory effects were observed in vitro when 5-HT was applied to whole worm preparations of Clonorchis sinensis. The stimulatory action of 5-HT was antagonized by tryptophol, clomipramine and imipramine. Strychnine remarkably stimulated motility. The action of strychnine was enhanced by 5-HT but inhibited by tryptophol. GABA, Phenylephrine, isoproterenol, dibenamine and phentolamine showed little influence on motility. Inhibitory effects were caused by eserine, arecoline, carbachol, DMPP and hemicholinium-3, but not by ACh, pilocarpine and McN-A-343. The inhibitory actions of eserine or carbachol were not antagonized by d-tubocurarine, hexamethonium or atropine. These results suggest that in regulating the motility of C. sinensis ACh may function as an inhibitory neurotransmitter and 5-HT as an excitatory transmitter in a manner similar to that already established for other trematodes such as Fasciola hepatica and Schistosoma mansoni.

Synthesis and hypoxia-selective cytotoxicity of a 2-nitroimidazole mustard

A four-step synthesis of 5-[N,N-bis(2-chloroethyl)amino]-1-methyl-2-nitroimidazole from 1-methyl-2-nitroimidazole is described. This compound showed similar hypoxia-selective cytotoxicity to the dinitrobenzamide mustard SN 23,862 in UV4 cells (ca. 40-fold), and superior selectivity (> 7-fold) in repair-competent AA8 cells.

Conjunctivitis caused by Thelazia callipaeda infestation in a woman

Thelazia is a nematode (Spirurida) that can parasitize the mammalian conjunctival sac. This is the first reported case of ocular. Thelazia callipaeda infestation in Taiwan. A 41-year-old woman experienced swelling, itching sensation and occasional blurred vision of the right eye 2 weeks after a small group of flies swarmed her eye while she was hiking. Her symptoms were first misdiagnosed as allergic conjunctivitis at a local medical clinic. During her first visit to our outpatient department, five white thread-like living worms were discovered on the superior and inferior fornices. The worms were cream-colored, slender and approximately 1 cm in length. Follicular and papillary conjunctivitis was noted in her right eye. After removing the worms, the symptoms resolved and no other worms were found in the following 2 months. This case is a remainder to physicians that parasitic infestation should be included in the differential diagnoses of ocular itching, conjunctivities, and blurred vision after insect contact.

Energy, macronutrient, and food intakes in relation to energy compensation in consumers who drink different types of milk

To examine whether total fat intake is actually lower in reduced-fat (low-fat and skim) milk drinkers and whether reduced-fat-milk drinkers compensate for energy intake we compared the intakes of foods, energy, and energy-yielding nutrients in reduced-fat-milk drinkers and whole milk drinkers by using the US Department of Agriculture's 1989-1991 nationwide food intake database, the Continuing Survey of Food Intakes by Individuals. This database represents a national stratified sample population of 15 128 individuals. Of the survey population, approximately one-third consumed whole milk, one-third consumed low-fat milk, one-tenth consumed skim milk, and one-tenth consumed mixed types of milk. The data provided the following information: 1) total fat intake of reduced-fat-milk drinkers is significantly (P < or = 0.05) lower than that of whole milk drinkers; 2) in general, males but not females compensate for energy by increasing their carbohydrate intake; 3) reduced-fat-milk drinkers consume more fruit and vegetables (P < or = 0.05) and less red meat and sweets (P < or = 0.05) than whole milk drinkers; 4) through their reduction in total fat intake, several age groups of skim milk drinkers have achieved the US dietary goal for fat intake, ie, < or = 30% of energy intake from fat; 5) teenagers compensate for energy intake the least of all age groups; and 6) with advancing age, fewer people drink milk and fewer drink whole milk. The data indicate significant sex differences in energy compensation, that reduced-fat-milk drinkers consume significantly (P < or = 0.05) less fat than whole milk drinkers, and that the US dietary goal for fat intake may be practically achieved by consuming reduced-fat foods such as skim milk and limiting intakes of high-fat foods such as red meat.

Occupational exposure to HIV, hepatitis B, hepatitis C, and tuberculosis

This article reviews risk of occupational exposure to bloodborne pathogens, specifically HIV, hepatitis B, and hepatitis C to healthcare workers. Information regarding assessing the risk of exposure, appropriate actions to take if an exposure occurs, the most recent recommendations for treatment and follow-up postexposure, and prevention strategies for avoiding exposure are presented. Additionally, current recommendations for the prevention of the transmission of tuberculosis in healthcare workers and the regulatory guidelines governing this topic are discussed.

Malignant eccrine spiradenoma with florid squamous differentiation

Malignant eccrine spiradenoma (MES) is an exceedingly rare neoplasm of cutaneous adnexal origin. To date, 31 cases have been documented in the literature. We herein report an additional case of MES that arose in longstanding eccrine spiradenoma (ES). A 54-year-old woman was seen for a bluish nodular mass on the right flank that previously had been stable for 7 to 8 years and had recently increased in size and become tender. The excised mass (2.8 x 2.5 x 2.5 cm) had no attachment to the overlying epidermis. Microscopically, 2 to 3 sharply demarcated lobules were surrounded by a markedly thickened and hyalinized fibrous capsule. Of the lesion removed, approximately 20% of the tumor showed typical histologic features of benign ES. In the remaining malignant areas, the typical configuration of benign counterpart, consisting of peripheral rows of small dark basaloid cells and central layers of large pale cells partially forming lumina, was replaced with a massive solid proliferation of large pale cells showing nuclear pleomorphism, prominent nucleoli, increased mitotic activity (reaching 12/10 HPF) and loss of PAS-positive basement membrane. There were multiple foci of florid squamous differentiation in the malignant portion. Cytokeratin, focally S-100 and EMA were expressed in large pale cells, whereas alpha smooth muscle actin and S-100 were positive in small dark basaloid cells. Focal reactivity of CEA and EMA was found in the central lumina. P53 was not expressed in benign areas, whilst in malignant areas an occasional nuclear reaction was disclosed.