[Molecular diagnostic strategies and management of dust mite allergy]

Dust mites are one of the most important allergens, widely distributed around the world, especially in household environments. Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis are the most common species of dust mites. There are more than 35 known sensitization components of dust mites, among which Der p 1, Der p 2 and Der p 23 are the major components. Clinically, allergen skin test and serum specific immunoglobulin E (sIgE) detection are widely used in the preliminary diagnosis of dust mite allergy. However, these methods cannot accurately identify specific dust mite sensitization components. Considering that there are significant differences in the allergenic components of dust mites in different regions and populations, component-resolved diagnosis of dust mite is particularly important in accurately determining the allergenic components. This is not only of guiding significance for allergen avoidance, but also important for determining the immunotherapy regimen for dust mites. In order to strengthen the understanding of the molecular diagnosis of dust mites and promote the integration of allergy science in China with the international standards, this article interprets the "Allergy Molecular Allergology User's Guide 2.0" published recently by the European Academy of Allergy and Clinical Immunology.

Effects of dietary niacinamide and CP concentrations on the nitrogen excretion, growth performance, and meat quality of pigs

Reducing the dietary CP concentration in the formulation of low-protein diets without adverse effects on animal growth performance and meat quality remains challenging. In this study, we investigated the effects of nicotinamide (NAM) on the nitrogen excretion, growth performance, and meat quality of growing-finishing pigs fed low-protein diets. To measure the nitrogen balance, we conducted two trials: in nitrogen balance trial 1, four crossbred (Duroc × Landrace × Large White) barrows (40 ± 0.5 kg BW) were used in a 4 × 4 Latin square design with four diets and periods. The diets consisted of a basal diet + 30 mg/kg NAM (a control dose), basal diet + 90 mg/kg NAM, basal diet + 210 mg/kg NAM, and basal diet + 360 mg/kg NAM. In nitrogen balance trial 2, another four barrows (40 ± 0.5 kg BW) were used in a 4 × 4 Latin square design. The diets consisted of a basal diet + including 30 mg/kg NAM (control), basal diet + 360 mg/kg NAM, low-protein diet + 30 mg/kg NAM, and low-protein diet + 360 mg/kg NAM. To measure growth performance, two trials were conducted. In growth performance trial 1, 40 barrows (37.0 ± 1.0 kg) were randomly allocated to one of four dietary treatments (n = 10 per group), whereas in growth performance trial 2, 300 barrows (41.4 ± 2.0 kg) were randomly allocated to one of four dietary treatments, with each dietary treatment conducted in five repetitions with 15 pigs each. The four diets in the two growth performance trials were similar to those in nitrogen balance trial 2. Supplementing the diet with 210 or 360 mg/kg NAM reduced urinary nitrogen excretion and total nitrogen excretion and increased nitrogen retention comparted with the control diet (P < 0.05). Compared with the control diet, the low-protein diet with 360 mg/kg NAM reduced faecal, urinary, and total nitrogen excretion (P < 0.05) without affecting nitrogen retention and average daily gain (P > 0.05). Pigs fed the low-protein diet with 360 mg/kg NAM showed a decreased intramuscular fat content in the longissimus thoracis muscle when compared with pigs fed the control diet (P > 0.05). Our results suggest NAM as a suitable dietary additive to reduce dietary CP concentration, maximise nitrogen retention and growth performance, and decrease fat deposition in pigs.

[Analysis of specific sIgE detection of house dust mites and aspergillus fumigatus in 2 535 patients with respiratory allergic diseases and respiratory infectious diseases in the Guangzhou area]

Objective: To compare the specific IgE positive rates of the patients between allergic respiratory diseases and respiratory infectious diseases in Guangzhou, the relationship between the co-sensitization of house dust mite (HDM) allergen and Aspergillus fumigatus (AF) allergen and asthma, allergic rhinitis with asthma, pneumonia, upper respiratory infections, bronchitis, serum total immunoglobulin E (total Immunoglobulin E, tIgE) and age were analyzed, to provide the basis for the prevention and treatment of respiratory allergic diseases and respiratory infectious diseases in this area. Methods: A total of 2 535 patients with confirmed respiratory allergic diseases and respiratory infectious diseases were selected retrospectively from the outpatient or inpatient department of the First Affiliated Hospital of Guangzhou Medical University from April 2017 to June 2021 and detected HDM and AF specific IgE (sIgE) by the ImmunoCAP system. The age range was 1 to 89 years. The median age was 5 years. The average age was 9. ≤3 years old group n=894, 4-6 years old group n=721, 7-18 years old group n=615, 19-49 years old group n=207, >49 years old group n=98. There were 1 596 males (62.96%) and 939 females (37.04%). There were 1 279 cases of allergic diseases and 1 256 cases of respiratory infectious diseases. The different disease groups were divided into asthma group (411 cases), allergic rhinitis group (458 cases), allergic rhinitis combined with asthma group (410 cases), pneumonia group (463 cases), upper respiratory tract infection group (299 cases) and bronchitis group (494 cases). The difference of specific IgE (sIgE) and tIgE between HDM and AF was analyzed. For statistical analysis, continuous variables were tested by Mann-Whitney U. Classification data by chi-square test or Fisher's exact test. Results: 1 313 (51.79%) patients were sIgE positive for HDM allergen, 65 (2.56%) were sIgE positive for AF allergen, and 50 (1.97%) were both positive. In the respiratory allergic disease group, 877 cases (68.57%,877/1 279) were positive for HDM allergen sIgE, 57 cases (4.46%,57/1 279) were positive for AF allergen sIgE, and 44 cases (3.44%,44/1 279) were both positive; 436 cases (34.71%,436/1 256) of respiratory infectious diseases were positive for HDM allergen sIgE, 8 cases (0.64%,8/1 256) were positive for AF allergen sIgE, and 6 cases (0.48%,6/1 256) were both positive. In monosensitization, the HDM allergen sIgE sensitization rate was the highest in the allergic rhinitis & asthma group, at 80.24% (329/410). The positive rate of HDM allergen sIgE in male patients was 53.76%(858/1 596), and the positive rate in female patients was 46.22%(434/939), and the difference between the two was statistically significant (χ²=13.449, P<0.001). In polysensitization, asthma patients (5.35%,22/411) had the highest positive rate of HDM sensitization with AF, followed by allergic rhinitis patients (3.06%,14/458), allergic rhinitis with asthma (1.95%,8/410). The positive rate of respiratory infectious diseases such as pneumonia (0.43%,2/463), upper respiratory infections (0.33%,1/299), and bronchitis (0.61%,3/494) with AF was extremely low. The positive rate of HDM combined with AF in infants(≤3 years old group,0.34%, 3/894; 4-6 years old group, 0.97%, 7/721)was significantly lower than that in teenagers and adults(7-18 years old group,3.58%, 22/615; 19-49 years old group,6.28%, 13/207;>49 years old group,5.10%, 5/98).In the patients with HDM and AF combined sensitization, HDM sIgE levels were distributed in all grades, and AF sIgE levels were mainly in grades 1, 2, and 3. Conclusion: The positive rate of HDM combined with AF was higher in patients with respiratory allergic diseases such as asthma, allergic rhinitis, and allergic rhinitis combined with asthma, suggesting that clinical attention should be paid to the combination of HDM and AF in patients with asthma and allergic rhinitis, especially adults, more likely to be combined with AF.

Two CoII coordination polymers of biphenyl-2,2',5,5'-tetracarboxylic acid with flexible N-donor ligands: syntheses, structures and magnetic properties

Two Co^II-based coordination polymers, namely poly[(μ₄-biphenyl-2,2',5,5'-tetracarboxylato){μ₂-1,3-bis[(1H-imidazol-1-yl)methyl]benzene}dicobalt(II)], [Co₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]_n or [Co₂(o,m-bpta)(1,3-bimb)₂]_n (I), and poly[[aqua(μ₄-biphenyl-2,2',5,5'-tetracarboxylato){1,4-bis[(1H-imidazol-1-yl)methyl]benzene}dicobalt(II)] dihydrate], {[Co₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂(H₂O)₂]·4H₂O}_n or {[Co₂(o,m-bpta)(1,4-bimb)₂(H₂O)₂]·4H₂O}_n (II), were synthesized from a mixture of biphenyl-2,2',5,5'-tetracarboxylic acid, i.e. [H₄(o,m-bpta)], CoCl₂·6H₂O and N-donor ligands under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis. The bridging (o,m-bpta)^4- ligands combine with Co^II ions in different μ₄-coordination modes, leading to the formation of one-dimensional chains. The central Co^II atoms display tetrahedral [CoN₂O₂] and octahedral [CoN₂O₄] geometries in I and II, respectively. The bis[(1H-imidazol-1-yl)methyl]benzene (bimb) ligands adopt trans or cis conformations to connect Co^II ions, thus forming two three-dimensional (3D) networks. Complex I shows a (2,4)-connected 3D network with left- and right-handed helical chains constructed by (o,m-bpta)^4- ligands. Complex II is a (4,4)-connected 3D novel network with ribbon-like chains formed by (o,m-bpta)^4- linkers. Magnetic studies indicate an orbital contribution to the magnetic moment of I and II due to the longer Co...Co distances. An attempt has been made to fit the χ_MT results to the magnetic formulae for mononuclear Co^II complexes, the fitting indicating the presence of weak antiferromagnetic interactions between the Co^II ions.

Synthesis, structure and selective luminescence sensing for iron(III) ions of a three-dimensional zinc(II) (4,6)-connected coordination network

Coordination polymers constructed from conjugated organic ligands and metal ions with a d¹⁰ electronic configuration exhibit intriguing properties for chemical sensing and photochemistry. A Zn^II-based coordination polymer, namely poly[aqua(μ₆-biphenyl-3,3',5,5'-tetracarboxylato)(μ₂-4,4'-bipyridine)dizinc(II)], [Zn₂(C₁₆H₆O₈)(C₁₀H₈N₂)(H₂O)₂]_n or [Zn₂(m,m-bpta)(4,4'-bipy)(H₂O)₂]_n, was synthesized from a mixture of biphenyl-3,3',5,5'-tetracarboxylic acid [H₄(m,m-bpta)], 4,4'-bipyridine (4,4'-bipy) and Zn(NO₃)₂·6H₂O under solvothermal conditions. The title complex has been structurally characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis, and features a μ₆-coordination mode. The Zn^II ions adopt square-pyramidal geometries and are bridged by two syn-syn carboxylate groups to form [Zn₂(COO)₂] secondary buildding units (SBUs). The SBUs are crosslinked by (m,m-bpta)^4- ligands to produce a two-dimensional grid-like layer that exhibits a stair-like structure along the a axis. Adjacent layers are linked by 4,4'-bipy ligands to form a three-dimensional network with a {4⁴.6¹⁰.8}{4⁴.6²} topology. In the solid state, the complex displays a strong photoluminescence and an excellent solvent stability. In addition, the luminescence sensing results indicate a highly selective and sensitive sensing for Fe³⁺ ions.

Identifying substance misuse in primary care: TAPS Tool compared to the WHO ASSIST

BACKGROUND

There is a need for screening and brief assessment instruments to identify primary care patients with substance use problems. This study's aim was to examine the performance of a two-step screening and brief assessment instrument, the TAPS Tool, compared to the WHO ASSIST.

METHODS

Two thousand adult primary care patients recruited from five primary care clinics in four Eastern US states completed the TAPS Tool followed by the ASSIST. The ability of the TAPS Tool to identify moderate- and high-risk use scores on the ASSIST was examined using sensitivity and specificity analyses.

RESULTS

The interviewer and self-administered computer tablet versions of the TAPS Tool generated similar results. The interviewer-administered version (at cut-off of 2), had acceptable sensitivity and specificity for high-risk tobacco (0.90 and 0.77) and alcohol (0.87 and 0.80) use. For illicit drugs, sensitivities were >0.82 and specificities >0.92. The TAPS (at a cut-off of 1) had good sensitivity and specificity for moderate-risk tobacco use (0.83 and 0.97) and alcohol (0.83 and 0.74). Among illicit drugs, sensitivity was acceptable for moderate-risk of marijuana (0.71), while it was low for all other illicit drugs and non-medical use of prescription medications. Specificities were 0.97 or higher for all illicit drugs and prescription medications.

CONCLUSIONS

The TAPS Tool identified adult primary care patients with high-risk ASSIST scores for all substances as well moderate-risk users of tobacco, alcohol, and marijuana, although it did not perform well in identifying patients with moderate-risk use of other drugs or non-medical use of prescription medications. The advantages of the TAPS Tool over the ASSIST are its more limited number of items and focus solely on substance use in the past 3months.

Why not nursing? A systematic review of factors influencing career choice among healthcare students

BACKGROUND

A global shortage of healthcare professionals calls for effective recruitment and retention strategies. The nursing profession faces greater staffing shortages compared with other healthcare professions. Identifying these factors for choosing a career in health care is an important step in structuring future nursing recruitment strategies.

AIM

This systematic review examined the motivations for choosing a career in health care, then compared them to factors that influence the choice to pursue a career in nursing.

METHODS

A literature search of the CINAHL, PubMed, Web of Science and Scopus databases for articles published between 2002 and 2013 was conducted. The search included studies that focused on factors influencing career choice among undergraduate medicine, dentistry, pharmacy and nursing students.

RESULTS

A total of 29 papers were included in the review. The themes and subthemes that emerged from this review included: (1) intrinsic factors, including a desire to help others and a personal interest in health care, (2) extrinsic factors, such as financial remuneration, job security, professional prestige and job autonomy, (3) socio-demographic factors such as gender and socio-economic status, and (4) interpersonal factors, encompassing the influence of family and other professional individuals.

DISCUSSION

Healthcare professionals were generally motivated by intrinsic factors. However, public perceptions of nursing as a low-paying and low-status job have significantly hindered the participants' choice to pursue it as a career.

CONCLUSION AND IMPLICATIONS FOR NURSING AND/OR HEALTH POLICY

Nursing institutions could provide more platforms to help school leavers better understand the nursing career. In turn, hospital administrators could invite parents to nursing career fairs, increase financial remuneration for nurses, and provide decision-making avenues aimed at recruiting and retaining more nurses.

Genetic association of blaSHV-5 with transposable elements IS26 and IS5 in Klebsiella pneumoniae from Taiwan

A cloned 5,248-bp EcoRI fragment from the Klebsiella pneumoniae transferable plasmid pKP53 (> 70 kb) containing bla(SHV-5) was sequenced. Insertion sequences IS26 and IS5 were found downstream from bla(SHV-5). The DNA sequences of the genetic environment surrounding bla(SHV-5) were homologous to plasmid p1658/97 from Escherichia coli, containing a truncated recF gene and a truncated deoR gene upstream and downstream from bla(SHV-5), respectively. RecF may be involved in bla(SHV-5) translocation to the plasmid by RecF-dependent recombination. This novel genetic environment may be associated with the successful proliferation and/or expression of SHV-5 in K. pneumoniae strains from Taiwan.

Effects of tannic acid and its related compounds on food mutagens or hydrogen peroxide-induced DNA strands breaks in human lymphocytes

The effect of tannic acid (TA), gallic acid (GA), propyl gallate (PA) and ellagic acid (EA) on DNA damage in human lymphocytes induced by food mutagens [3-amino-1-methyl-5H-pyrido (4,3-b) indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimadazo (4,5-b) pyridine (PhIP) or H2O2 was evaluated by using single-cell electrophoresis (comet assay). The toxicity of these tested compounds (0.1-100 microg/ml) on lymphocytes was not found. These compounds did not cause DNA strand breaks at lower concentrations of 0.1-10 microg/ml. At a concentration of 100 microg/ml, TA and GA exhibited slight DNA damage, whereas PA and EA showed no DNA strand breaks. TA and its related compounds decreased the DNA strand breaks induced by Trp-P-2, PhIP or H2O2 at concentrations of 0.1-10 microg/ml. DNA repair enzymes endonuclease III (Endo III) and formamidopyrimidine-DNA glycoslase (FPG)] were used to examine the levels of oxidised pyrimidines and purines in human lymphocytes induced by H2O2. All the compounds at 10 microg/ml can reduce the level of FPG sensitive sites. However, only EA inhibited the formation of EndoIII sensitive sites. The results indicated that these compounds can enhance lymphocytes resistance towards DNA strand breaks induced by food mutagens or H2O2 in vitro.

Effect of norcantharidin on N-acetyltransferase activity in HepG2 cells

The inhibition ofarylamine N-acetyltransferase (NAT) activity by norcantharidin (NCTD), the demethylated form of cantharidin, in human hepatocellular carcinoma HepG2 cells was investigated. By using high performance liquid chromatography, NAT activity on acetylation of 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) were examined. Two assay systems were performed, one with cellular cytosols, the other with intact HepG2 cell suspensions. The NAT activity in HepG2 cell line was inhibited by norcantharidin in a dose-dependent manner in both types of examined systems: i.e. the greater the concentration of norcantharidin in the reaction, the greater the inhibition of NAT activities. This report is the first to show that norcantharidin has an inhibitory effect on NAT activity in HepG2 cell.

Engineering, expression, and renaturation of a collagen-targeted human bFGF fusion protein

Basic fibroblast growth factor (bFGF) is a potent in vitro mitogen for capillary endothelial cells, stimulates angiogenesis in vivo, and may participate in tissue repair. Basic FGF is found in abundance in tissues such as brain, kidney and cartilage. This study reports the expression, purification, and renaturation of a biologically active human basic fibroblast growth factor fusion protein (hbFGF-F1) from Escherichia coli. A prokaryotic expression vector was engineered to produce a tripartite fusion protein consisting of (i) a purification tag, (ii) a protease-sensitive linker/collagen-binding domain, and (iii) cDNA sequence encoding the active fragment of hbFGF. The expressed hbFGF-F1 and hbFGF-F2 (it contains a collagen-binding domain), located in inclusion bodies, were solubilized with 6 M guanidine-HCl and renatured using a glutathione redox system and protracted dialysis under various experimental conditions. The purification of the recombinant proteins was achieved by binding the His-tag of the fusion protein on a Ni-NTA metal chelate column. The biological activity of the recombinant growth factors was demonstrated by their ability to stimulate proliferation of human vein endothelial cells (HVEC), monitored by [3H]-thymidine incorporation, where commercial recombinant human bFGF (rhbFGF) served as a positive control. Purified rhbFGF-F1 and rhbFGF-F2 constructs exhibited proliferative activity comparable to commercial rhbFGF. Binding of the renatured hbFGF-F2 fusion protein to collagen was demonstrated by stable binding on a collagen-conjugated Sephadex-G15 column. The high affinity binding was also demonstrated by the binding of [3H]-collagen to the rhbFGF-F2 protein immobilized on a Ni-NTA column. The rhbFGF-F2 fusion protein bound to collagen coated surfaces with high affinity but exhibited comparatively lower biological activity than the fusion protein in solution, suggesting a potentially latent configuration. Taken together, these results demonstrate that biologically active rhbFGF fusion proteins can be recovered from transformed bacteria by oxidative refolding; thus, providing a means for its high-yield production, purification, and renaturation from microorganisms. Furthermore, we demonstrate that the auxiliary collagen-binding domain effectively targets the recombinant growth factor to type I collagen. The clinical effect of rhbFGF-F2 on wound healing is also studied in streptozotocin-induced diabetic rats and evaluated by histological examination comparing with rhbFGF-F1 and commercial bFGF effects. The highly beneficial effects of rhbFGF-F2 on wound healing is suggested to be due to its extremely potent angiogenesis and granulation tissue formation activities, leading to a rapid reepithelialization of the wound. Topical application of rhbFGF-F2 mixed with type I collagen is a more effective method in accelerating closure of full-thickness excisional skin-wound in diabetic rats when compared with the fusion protein alone or commercial hbFGF at the same doses. These studies advance the technology necessary to generate large quantities of targeted bFGF fusion proteins as well as to develop new strategies for specific biomedical applications.

Production of a recombinant human basic fibroblast growth factor with a collagen binding domain

Basic fibroblast growth factor (bFGF) is a potent in vitro mitogen for capillary endothelial cells, stimulates angiogenesis in vivo, and may participate in tissue repair. Basic FGF is found in abundance in tissues such as brain, kidney, and cartilage. This study reports the expression, purification, and renaturation of a biologically active human basic fibroblast growth factor fusion protein (hbFGF-F1) from Escherichia coli. A prokaryotic expression vector was engineered to produce a tripartite fusion protein consisting of a purification tag, a protease-sensitive linker and collagen binding domain, and a cDNA sequence encoding the active fragment of hbFGF. The expressed hbFGF-F1 and hbFGF-F2 (it contains the collagen binding domain), located in inclusion bodies, were solubilized with 6 M guanidine-HCl and renatured by a glutathione redox system and protracted dialysis under various experimental conditions. The purification of the recombinant proteins was achieved by binding the His-tag of the fusion protein on a nickel-nitrilotriacetic acid metal chelate column. The biological activity of the recombinant growth factor was demonstrated by its ability to stimulate proliferation of human vein endothelial cells, monitored by [3H]thymidine incorporation, where commercial recombinant human bFGF (rhbFGF) served as a positive control. Purified rhbFGF-F1 and rhbFGF-F2 constructs exhibited proliferative activity comparable to commercial rhbFGF. The high-affinity binding was demonstrated by the binding of [3H]collagen to the rhbFGF-F2 protein immobilized on a Ni-nitrilotriacetic acid column. The rhbFGF-F2 fusion protein bound to collagen-coated surfaces with high affinity. Taken together, these results demonstrate that biologically active rhbFGF fusion proteins can be recovered from transformed bacteria by oxidative refolding; thus, providing a means for their high-yield production, purification, and renaturation from microorganisms. Furthermore, we demonstrate that the auxiliary collagen binding domain effectively targets the recombinant growth factor to type I collagen. These studies advance the technology necessary to generate large quantities of targeted bFGF fusion proteins for specific biomedical applications.

The estimated rate of depressed mood in US adults: recent evidence for a peak in later life

OBJECTIVE

The main aim of this study is to add new evidence on the descriptive epidemiology of depressed mood, and to investigate suspected determinants for depressed mood in adulthood.

METHODS

The data are from a continuing survey of a nationally representative sample of adult household residents in the United States, conducted in 1995 and 1996, totaling 26,883 respondents. Multiple logistic regression procedures yielded estimated associations.

RESULTS

We found that an estimated 1.9% of adult females and 1.0% of adult males experience a spell of sustained depressed mood during a span of approximately 2 weeks duration (i.e. point prevalence). For most of these cases, this is not the first spell. Among women, the smoothed curve for the prevalence estimates shows a peak in the youngest age stratum and decreases across age strata before 60 years, and has a slight secondary peak thereafter. In contrast, for males, the prevalence estimates of depression show no peak in the older age strata. Evidence from logistic regression analyses supports the inference of this later life peak in frequency of depressed mood among women. These new findings add to a growing body of epidemiological evidence on age and depression, and provoke new questions about the possibly etiological relationships involving social structural characteristics of local neighborhoods in combination with individual-level risk factors that have received primary attention in recent psychiatric epidemiology.

CONCLUSIONS

These findings point to the need for further etiological research, including studies of relationships between social structural characteristics of local neighborhoods and the occurrence of spells of depressed mood, as well as clinical implications for depression mood in late life.

Characterization of the IncW cryptic plasmid pXV2 from Xanthomonas campestris pv. vesicatoria

The gram-negative plant pathogen Xanthomonas campestris pv. vesicatoria strain Xv2 harbors an indigenous, cryptic plasmid pXV2 of 14.6 kb. This plasmid can only be maintained in Xanthomonas and is incapable of self-transmission. However, incompatibility testing classified it in IncW, a group containing the smallest number of naturally occurring, broad-host-range, conjugative plasmids. A pXV2 derivative containing only a 5.5-kb PstI fragment is stably maintained. Deletion of a 3.0-kb region from the PstI fragment causes a loss of plasmid stability. Nucleotide sequencing of the 2. 1-kb region essential for autonomous replication revealed a repA gene and a downstream noncoding region containing four iterons, two 17- and two 19-nt direct repeats, and an AT-rich region lying between the two sets of iterons. The sequence of the deduced RepA and the iterons shows homology to the RepA (39% identity) and the iterons, respectively, of the IncW plasmid pSa. Maxicell expression of the repA gene produced a protein of 35 kDa, a size similar to that deduced from the nucleotide sequence. Trans-complementation test confirmed that the repA gene and the iterons are indeed the essential elements for pXV2 replication.

The use of the case-crossover design in studying illicit drug use

The case-crossover design was developed to study time-varying exposures that cause transient excess risk of acute health events. It is a variant of case-control and subject-as-own-control research designs, involving use of information about exposure history of each case to estimate the transient effect. This kind of self-control design can help to reduce sampling bias otherwise introduced in the selection of controls, as well as confounding bias that might be derived from enduring individual characteristics, especially personality traits and other long-standing inherited or acquired vulnerabilities. When the subject is used as his or her own control, these personal vulnerabilities are matched. In this paper we discuss strengths and weaknesses of the case-crossover design and suggest applications of the case-crossover design in epidemiologic studies on suspected hazards of illicit drug use, and in studies of drug use and co-occurring psychiatric disturbances. We conclude that the case-crossover design can play a useful role, but it discloses a need to secure fine-grained measurements in epidemiologic research on psychiatric comorbidity. As explained in the paper, we also believe the case-crossover method may be of use to criminologists who study the drugs-crime nexus, to services researchers and clinicians who seek to understand treatment entry and compliance behavior, and to etiologists interested in polydrug use.

Effects of caffeic acid, chlorogenic acid and ferulic acid on growth and arylamine N-acetyltransferase activity in Shigella sonnei (group D)

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene (2-AF) as substrates were determined in Shigella sonnei (group D) collected from patients with diarrhoeal disease. The NAT activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. Inhibition of growth studies from S. sonnei (group D) demonstrated that caffeic acid (CA), chlorogenic acid (CGA) and ferulic acid (FA) elicited a dose-dependent bactericidal effect in S. sonnei (group D) cultures, i.e. the greater the concentration of CA, CGA and FA, the greater the inhibition of growth of S. sonnei (group D). Cytosols or suspensions of S. sonnei (group D) with and without selected concentrations of CA, CGA and FA co-treatment showed different percentages of 2-AF acetylation. The data indicated that there was reduced NAT activity associated with increased CA, CGA and FA in Shigella dysenteriae (group D) cytosols and intact cells. For the cytosol and intact bacteria examinations, the apparent values of K(m) and Vmax decreased after being co-treated with 400 microM CA, CGA and FA. This report is the first demonstration of plant phenolic inhibition (CA, CGA and FA) of arylamine NAT activity and growth in the bacterium S. sonnei (group D).

Tobacco smoking and depressed mood in late childhood and early adolescence

OBJECTIVES

This study builds on previous observations about a suspected causal association linking tobacco smoking with depression. With prospective data, the study sheds new light on the temporal sequencing of tobacco smoking and depressed mood in late childhood and early adolescence.

METHODS

The epidemiologic sample that was studied consisted of 1731 youths (aged 8-9 to 13-14 years) attending public schools in a mid-Atlantic metropolitan area, who were assessed at least twice from 1989 to 1994. A survival analysis was used to examine the temporal relationship from antecedent tobacco smoking to subsequent onset of depressed mood, as well as from antecedent depressed mood to subsequent initiation of tobacco use.

RESULTS

Tobacco smoking signaled a modestly increased risk for the subsequent onset of depressed mood, but antecedent depressed mood was not associated with a later risk of starting to smoke tobacco cigarettes.

CONCLUSIONS

This evidence is consistent with a possible causal link from tobacco smoking to later depressed mood in late childhood and early adolescence, but not vice versa.

Panic attacks and suicide attempts in mid-adolescence

OBJECTIVE

The aim of this study was to investigate the association of panic attacks and suicide attempts in a community-based sample of 13-14-year-old adolescents.

METHOD

The data are from a survey of 1,580 students in an urban public school system located in the mid-Atlantic region of the United States. Logistic regression methods were used to estimate associations between panic attacks and suicidal ideation and suicide attempts.

RESULTS

Controlling for demographic factors, major depression, the use of alcohol, and the use of illicit drugs, the authors found that adolescents with panic attacks were three times more likely to have expressed suicidal ideation and approximately two times more likely to have made suicide attempts than were adolescents without panic attacks.

CONCLUSIONS

This new epidemiologic research adds to the evidence of an association between panic attacks and suicide attempts during the middle years of adolescence.

Effects of berberine on arylamine N-acetyltransferase activity in human colon tumor cells

Berberine was used to determine loss of viable cells and inhibition of arylamine Nacetyltransferase (NAT) activity in a human colon tumor (adenocarcinoma) cell line. The viable cells were determined by trypan blue exclusion under a light microscope. The NAT activity was measured by high performance liquid chromatography for the amounts of N-acetyl-2-aminofluorene (AAF), N-acetyl-p-aminobenzoic acid (N-Ac-PABA), and the remaining 2-aminofluorene (AF) and p-aminobenzoic acid (PABA). The viability and NAT activity in a human colon tumor cell line was inhibited by berberine in a dose-dependent manner, i.e., the higher the concentration of berberine, the higher the inhibition of NAT activity and cell death. The NAT activities measured in the intact human colon tumor cells were decreased over 50% by AAF and NAc-PABA production from acetylation of AF and PABA. The apparent values of Kmoff and Vmax of NAT from colon tumor cells were also inhibited by berberine in cytosols and in intact cells. This report is the first to show that berberine did affect human colon tumor cell NAT activity.

Influence of comorbid alcohol and psychiatric disorders on utilization of mental health services in the National Comorbidity Survey

OBJECTIVE

This study sought to determine how comorbidity of psychiatric and substance abuse disorders affects the likelihood of using mental health services.

METHOD

The analysis was based on data on adults aged 18-54 years in the National Comorbidity Survey (N = 5,393). Users and nonusers of mental health and substance abuse services were compared in terms of their demographic characteristics, recent stressful life events, social support, parental history of psychopathology, self-medication, and symptoms of alcohol abuse/dependence.

RESULTS

The prevalence of service utilization varied by diagnostic configurations. Comorbid psychiatric or alcohol disorders were stronger predictors of service utilization than a pure psychiatric or alcohol disorder. Factors predicting utilization of services differed for each disorder.

CONCLUSIONS

Since comorbidity increases the use of mental health and substance abuse services, research on the relationship of psychiatric and alcohol-related disorders to service utilization needs to consider the coexistence of mental disorders. Attempts to reduce barriers to help seeking for those in need of treatment should be increased.

Tobacco smoking and other suspected antecedents of nonmedical psychostimulant use in the United States, 1995

This study investigates the extent to which tobacco smoking is associated with the nonmedical use of psychostimulants and the temporal order of the age of first use for tobacco and psychostimulants within a nationally representative sample of United States household residents. At the same time, alcohol use and other suspected determinants of psychostimulant use are investigated and held constant, using multiple regression models. Data were taken from public use files of the 1995 National Household Survey on Drug Abuse. Conditional logistic regression analyses were performed to derive estimated relative odds of using stimulants for tobacco smokers versus nonsmokers, holding constant other potentially distorting influences. This study provides recent evidence on tobacco smoking as one of the potentially malleable risk factors for the nonmedical use of stimulant drugs.

Effects of berberine on arylamine N-acetyltransferase activity in human bladder tumour cells

Berberine was used to determine inhibition of arylamine N-acetyltransferase (NAT) activity in human bladder tumour cells. The NAT activity was measured by HPLC assaying for the amounts of N-acetyl-2-aminofluorene (AAF) and N-acetyl-p-aminobenzoic acid (N-Ac-PABA) and remaining 2-aminofluorene (AF) and p-aminobenzoic acid (PABA). Two assay systems were performed, one with cellular cytosols, the other with intact bladder tumour cell suspensions. The NAT activity in human bladder tumour cells was inhibited by berberine in a dose-dependent manner, that is, the higher the concentration of berberine, the higher the inhibition of NAT activity. The values of apparent Km and Vmax calculated from cytosol NAT and intact cells were also decreased by berberine. This report is the first demonstration to show berberine did affect human bladder tumour cell NAT activity.

Effects of garlic compounds diallyl sulfide and diallyl disulfide on arylamine N-acetyltransferase activity in strains of Helicobacter pylori from peptic ulcer patients

Arylamine N-acctyltransferase (NAT) activities with p-aminobenzoic acid (PABA) and 2-aminofluorene (2-AF) were determined in the bacterium Helicobacter pylori collected from peptic ulcer patients. Two assay systems were performed, one with cellular cytosols, the other with intact cell suspensions. Cytosols or suspensions of H. pylori with or without specific concentrations of diallyl sulfide (DAS) or diallyl disulfide (DADS) co-treatment showed different percentages of 2-AF and PABA acetylation. The data indicated that there was decreased NAT activity associated with increased levels of DAS or DADS in H. pylori cytosols and suspensions. Viability studies on H. pylori demonstrated that DAS or DADS elicited dose-dependent bactericide affects on H. pylori cultures. The data also indicated that DAS and DADS decreased the apparent values of K(m) and Vmax of NAT enzyme from H. pylori in both systems examined. This report is the first demonstration that garlic components can affect H. pylori growth and NAT activity.

Characterization of arylamine N-acetyltransferase in Enterobacter aerogenes

N-acetyltransferase (NAT) activity was determined by incubation of purified Enterobacter aerogenes enzyme with 2-aminofluorene (2-AF) as the substrate, followed by high pressure liquid chromatography assays. The NAT activity from E. aerogenes was 0.58 +/- 0.08 nmol/min/mg protein for 2-AF. The values of apparent K(m) and Vmax were 0.72 +/- 0.14 mM and 2.45 +/- 0.29 nmol/min/mg protein, respectively, for 2-AF. The optimal pH value for the enzyme activity was 7.5 for the 2-AF tested. The optimal temperature for enzyme activity was 37 degrees C for the 2-AF substrate. The molecular weight of NAT from E. aerogenes was 44.9 kD. Among a series of divalent cations and salts, Zn2+, Ca2+, and Fe2+ were demonstrated to be the most potent protease inhibitors, and only ethylenediaminetetraacetic acid significantly protected the NAT. Iodoacetamide, in contrast to other agents, markedly inhibited NAT.

Effects of vitamin C on arylamine N-acetyltransferase activity in human liver tumor cells

Arylamine N-acetyltransferase (NAT) activity in a human liver tumor (heptoma) cell line was inhibited by vitamin C. Using high performance liquid chromatography, NAT activity on the acetylation of 2-aminofluorene and p-aminobenzoic acid was examined. Two assay systems were performed, one with cellular cytosols, the other with intact liver tumor cell suspensions. The NAT activity in a human liver tumor cell line was inhibited by vitamin C in a dose-dependent manner in both types of examined system: i.e. the greater the concentration of vitamin C in the reaction, the greater the inhibition of NAT activities in both systems examined. The data also indicated that vitamin C decreased the apparent Km and Vmax of NAT enzymes from human liver tumor cells in both systems examined. This report is the first demonstration which showed vitamin C effect on human liver tumor cell NAT activity.

Rhein affects arylamine N-acetyltransferase activity in Helicobacter pylori from peptic ulcer patients

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene and p-aminobenzoic acid were determined in the bacterium Helicobacter pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without specific concentrations of rhein co-treatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicate that there was decreased NAT activity associated with increased levels of rhein in H. pylori cytosols. Inhibition of growth studies from H. pylori demonstrated that rhein elicited dose-dependent bacteriostatic activity in H. pylori cultures: i.e. the greater the concentration of rhein, the greater the inhibition of growth to H. pylori. For the cytosol and intact bacteria examination, the apparent values of Km and Vmax were decreased after co-treatment with 40 microM rhein. This report is the first demonstration of rhein inhibition of arylamine N-acetyltransferase activity and rhein inhibition of growth in the bacterium H. pylori.

Rhein affects arylamine N-acetyltransferase activity in Helicobacter pylori from peptic ulcer patients

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene and p-aminobenzoic acid were determined in the bacterium Helicobacter pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without specific concentrations of rhein co-treatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicate that there was decreased NAT activity associated with increased levels of rhein in H. pylori cytosols. Inhibition of growth studies from H. pylori demonstrated that rhein elicited dose-dependent bacteriostatic activity in H. pylori cultures: i.e. the greater the concentration of rhein, the greater the inhibition of growth to H. pylori. For the cytosol and intact bacteria examination, the apparent values of Km and Vmax were decreased after co-treatment with 40 microM rhein. This report is the first demonstration of rhein inhibition of arylamine N-acetyltransferase activity and rhein inhibition of growth in the bacterium H. pylori.

Aloe-emodin effects on arylamine N-acetyltransferase activity in the bacterium Helicobacter pylori

Arylamine N-acetyltransferase (NAT) activities with p-aminobenzoic acid (PABA) and 2-aminofluorene (AF) were determined in H. pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without different concentrations of aloe-emodin co-treatment showed different percentages of AF and PABA acetylation. The data indicate that there was decreased NAT activity associated with increased aloe-emodin in H. pylori cytosols. Inhibition of growth study from H. pylori demonstrated that aloe-emodin elicited dose-dependent growth inhibition in H. pylori cultures. The report is the first finding of aloe-emodin inhibition of arylamine NAT activity in a strain of H. pylori.

Inhibitory actions of emodin on arylamine N-acetyltransferase activity in strains of Helicobacter pylori from peptic ulcer patients

Arylamine N-acetyltransferase (NAT) activities with p-aminobenzoic acid and 2-aminofluorene were determined in Helicobacter pylori, a gram-negative rod bacteria collected from peptic ulcer patients. The NAT activity was determined using a acetyl CoA recycling assay and HPLC. Cytosols or suspensions of H. pylori with and without selected concentrations of emodin co-treatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicate that there were decreased NAT activity associated with increased emodin in H. pylori cytosols. As 400 microns of emodin can obviously inhibit NAT activity both in vitro and in vivo (inhibition rate 90% and 93% for 2-aminofluorene and p-aminobenzoic acid in vitro, and 90% and 92%, respectively, for both substrate in vivo). For in vitro examination, the apparent values of Km and Vmax were 3.12 +/- 0.38 mM and 15.20 +/- 3.16 nmol/min/mg protein for 2-aminofluorene, and 0.56 +/- 0.12 mM and 0.74 +/- 0.09 nmol/min mg protein for p-aminobenzoic acid. However, when emodin was added to the reaction mixtures, the values of apparent Km and Vmax were 2.40 +/- 0.32 mM and 10.62 +/- 0.04 nmol/min/mg protein for 2-aminofluorene, and 0.23 +/- 0.02 mM and 0.62 +/- 0.08 nmol/min/mg protein for p-aminobenzoic acid. For in vivo examination, the apparent Km and Vmax were 0.82 +/- 0.18 mM and 0.92 +/- 0.21 nmol/min/10 x 10(10) colony forming units (CFU) for 2-aminofluorene, and 0.78 +/- 0.14 mM and 0.52 +/- 0.06 nmol/min/ 10 x 10(10) (CFU) for p-aminobenzoic acid. However, when emodin was added to the reaction mixtures, the values of apparent Km and Vmax were 0.50 +/- 0.08 mM and 0.62 +/- 0.22 nmol/min/ 10 x 10(10) (CFU) for 2-aminofluorene, and 0.52 +/- 0.21 mM and 0.26 +/- 0.04 nmol/min/ 10 x 10(10) (CFU) for p-aminobenzoic acid. This report is the first finding of emodin inhibition of arylamine N-acetyltransferase activity in a strain of H. pylori.

Arylamine N-acetyltransferase activity in Staphylococcus aureus

N-Acetyltransferase (NAT) activities were determined by incubation of Staphylococcus aureus cytosols with p-aminobenzoic acid (PABA) or 2-aminofluorene (2-AF) followed by high pressure liquid chromatography assays. The NAT activities from S. aureus were found to be 0.67 +/- 0.04 nmol/min/mg protein for the acetylation of 2-AF and 0.46 +/- 0.02 nmol/min/mg protein for the acetylation of PABA. The apparent K(m) and Vmax values obtained were 2.85 +/- 0.65 mM and 7.51 +/- 0.86 nmol/min/mg protein for 2-AF, and 2.35 +/- 0.39 mM and 9.43 +/- 0.78 nmol/min/mg protein for PABA, respectively. The optimal pH value for the enzyme activity was 7.0 for both substrates tested. The optimal temperature for enzyme activity was 37 degrees C for both substrates. The NAT activity was inhibited by iodoacetamide at 0.25 mM, and activity was reduced 50%. At 1.0 mM iodoacetamide activity was inhibited more than 90%. Among a series of divalent cations and salts, Zn2+, Ca2+, and Fe2+ were demonstrated to be the most potent inhibitors. The molecular weight of NAT from S. aureus was found to be 44.9 kDa. This report is the first demonstration of acetyl CoA: arylamine NAT activity in S. aureus.

Evidence for arylamine N-acetyltransferase activity in the bacterium Helicobacter pylori

N-Acetyltransferase activities with p-aminobenzoic acid and 2-aminofluorene were determined in Helicobacter pylori from gastroduodenal disease patients. The N-acetyltransferase activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. The N-acetyltransferase activities from a number of Helicobacter pylori samples were found to be 0.91 +/- 0.12 nmole/min/mg protein for the acetylation of 2-aminofluorene and 0.75 +/- 0.22 nmole/min/mg protein for the acetylation of p-aminobenzoic acid. The apparent K(m) and V(max) values obtained were 1.10 +/- 0.08 mM and 2.34 +/- 0.14 nmol/min/mg protein for 2-aminofluorene, and 0.92 +/- 0.09 mM and 2.08 +/- 0.16 nmol/min/mg protein for p-aminobenzoic acid. The optimal pH value for the enzyme activity was 6.0 for both substrates tested. The optimal temperature for enzyme activity was 37 degrees C for both substrates. The N-acetyltransferase activity was inhibited by iodacetamide: at 0.25 mM iodacetamide, activity was reduced 50% and 1.0 mM iodacetamide inhibited activity more than 90%. Among a series of divalent cations and salts, Cu2+ and Zn2+ were demonstrated to be the most potent inhibitors. Among the protease inhibitors, only ethylenediaminetetraacetic acid significantly protected N-acetyltransferase. Iodoacetic acid, in contrast to the other agents, markedly inhibited N-acetyltransferase. This is the first demonstration of acetyl CoA:arylamine N-acetyltransferase activity in Helicobacter pylori.

Evidence for arylamine N-acetyltransferase in Hymenolepis nana

N-acetyltransferase activities with p-aminobenzoic acid and 2-aminofluorene were determined in Hymenolepis nana, a cestode found in the intestine of the Sprague-Dawley rats. The N-acetyltransferase activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. The N-acetyltransferase activities from a number of Hymenolepis nana whole tissue homogenizations were found to be 2.83 +/- 0.31 nmole/min/mg for 2-aminofluorene and 2.07 +/- 0.24 nmole/min/mg for p-aminobenzoic acid. The apparent Km and Vmax were 1.06 +/- 0.38 mM and 8.92 +/- 1.46 nmol/min/mg for 2-aminofluorene, and 2.16 +/- 0.19 mM and 12.68 +/- 2.26 nmol/min/mg for p-aminobenzoic acid. The optimal pH value for the enzyme activity was pH 8.0 for both substrates tested. The optimal temperature for enzyme activity was 37 degrees C for both substrates. The N-acetyltransferase activity was inhibited by iodacetamide. At 0.25 mM iodacetamide the activity was reduced 50% and 1.0 mM iodacetamide inhibited activity more than 90%. Among a series of divalent cations and salts, Fe2+, Ca2+ and Zn2+ were demonstrated to be the most potent inhibi-tors. Among the protease inhibitors, only ethylenediaminetetraacetic acid significantly protected N-acetyltransferase. Iodoacetate, in contrast to other agents, markedly inhibited N-acetyltransferase activity. This is the first demonstration of acetyl CoA:arylamine N-acetyltransferase activity in a cestode and extends the number of phyla in which this activity has been found.

Engineering, expression and renaturation of targeted TGF-beta fusion proteins

This study reports the expression, purification, and renaturation of biologically active Transforming Growth Factor-beta 1 (TGF-beta 1) fusion proteins from Escherichia coli (E. coli). A prokaryotic expression vector was engineered to produce tripartite fusion proteins consisting of (i) a purification tag, (ii) a protease-sensitive linker/collagen binding domain, and (iii) a cDNA sequence encoding the active fragment of human TGF-beta 1. The expressed fusion proteins TGF-B1-F1 and TGF-B1-F2, located in inclusion bodies, were solubilized with 8 M urea and renatured using a glutathione redox-coupled system and protracted dialysis under several experimental conditions. The purification of the recombinant proteins was achieved by binding the His-tag of the fusion proteins on a Ni-NTA metal chelate column. The biological activity of the recombinant growth factor was demonstrated by its ability to inhibit mink lung (Mv1Lu) cell proliferation and/or to stimulate proliferation of NIH-3T3 mouse fibroblasts, where purified human platelet TGF-beta 1 served as a positive control. Purified TGF-B1-F1 and TGF-B1-F2 (collagen-binding) constructs exhibited anti-proliferative activities comparable to purified platelet TGF-beta 1, but at lower specific activities. Binding of the renatured TGF-B1-F2 fusion protein to collagen was demonstrated by stable binding on a collagen-conjugated Sephadex-G15 column. The high affinity binding was also demonstrated by the binding of 3H-collagen to the TGF-B1-F2 protein immobilized on a Ni-NTA column. The TGF-B1-F2 fusion protein bound to collagen coated surfaces with high affinity but exhibited comparatively lower biological activity than the fusion protein in solution, suggesting a potentially latent configuration. Taken together, these results demonstrate that biologically active TGF-beta 1 fusion proteins can be recovered from transformed bacteria by oxidative refolding; thus, providing a means for its high-yield production, purification, and renaturation from microorganisms. Furthermore, these results support the concept that auxiliary domains may be used to modulate and/or target TGF-beta 1 for specific applications.

Surgical treatment of spinal cord compression from epidural metastasis

PURPOSE

A retrospective study of the results of neoplastic cord compression was undertaken to determine the effectiveness of surgical treatment and to assess quality of life in patients undergoing extensive procedures with potential morbidity.

PATIENTS AND METHODS

Over a 5-year period (1989 to 1993), a total of 110 patients underwent surgery. Fifty-five patients (50%) had undergone prior treatment, including 47 (43%) who had failed to respond to prior irradiation (RT). Before surgery, 48 patients (44%) were nonambulatory, with severe paresis being present in 20. Surgery included staged anterior-posterior resections in 53 patients (48%), anterior resections in 33 (30%), and posterior resection in six (5%), all of whom required spinal instrumentation for reconstruction; only 18 patients underwent resection without instrumentation.

RESULTS

Postoperatively, 90 patients (82%) were improved, both in terms of pain relief and ambulatory status. Fifty-three patients (48%) experienced postoperative complications, related statistically to the following three factors: age over 65 years, prior treatment, and presence of paraparesis. The overall median survival duration was 16 months, with 46% alive at 2 years. Apart from primary tumor, the presence of preoperative paraparesis had the most significant impact on survival.

CONCLUSION

Our data suggest that the effective surgical treatment of neoplastic compression requires anterior-posterior resection in most patients to achieve the goal of total tumor resection, with the majority requiring instrumentation. Long-term survival is feasible in a subset of patients with this aggressive surgical approach.

Treatment of advanced medullary thyroid carcinoma with a combination of cyclophosphamide, vincristine, and dacarbazine

BACKGROUND

Medullary thyroid carcinoma (MTC) is a neoplasm of the parafollicular C cells of the thyroid gland, which belongs to the diffuse neuroendocrine system. This cancer usually behaves in a relatively indolent manner for most patients. However, approximately 20% of patients have a more aggressive course that requires effective management. There are few reported clinical trials of chemotherapy for MTC. From the literature, the most active agent appears to be doxorubicin, with response rates of 30% reported. On the basis of the activity of cyclophosphamide, vincristine, and dacarbazine (CVD) in other advanced neuroendocrine neoplasms, the authors tested the combination in patients with advanced MTC.

METHODS

Seven patients with advanced MTC were treated with cyclophosphamide (750 mg/m2), vincristine (1.4 mg/m2), and dacarbazine (600 mg/m2 daily for 2 days in each cycle) every 3 weeks. Assessments of measurable tumor and serum calcitonin and carcinoembryonic antigen were made before treatment and followed up until progressive disease was documented.

RESULTS

Two patients had partial tumor and biochemical responses for a duration of 14 and 29 months, respectively. One patient had a partial biochemical response and stable tumor measurements for 9 months, and another patient had stable tumor size and markers for 14 months. Three patients had progressive disease. Diarrhea and flushing improved in two patients who had partial biochemical responses.

CONCLUSION

Our experience suggests that CVD chemotherapy has moderate activity and is well tolerated in patients with advanced MTC. Additional prospective studies of this regimen for MTC are required.

Hypertensive crises induced by treatment of malignant pheochromocytoma with a combination of cyclophosphamide, vincristine, and dacarbazine

Combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine (CVD) is an effective treatment regimen for malignant pheochromocytoma. There have not been any significant acute cardiovascular effects reported following CVD treatment. Among seven patients with malignant pheochromocytoma treated with CVD at our institution, two patients with labile hypertension developed hypertensive crisis following CVD treatment. The marked increase in blood pressure correlated with an increase in urinary excretion of catecholamine metabolites in one patient. Further hypertensive crises following subsequent CVD treatments were avoided by optimizing each patient's antiadrenergic therapy. Similar to the approach used preoperatively for patients with resectable pheochromocytoma, maximal antiadrenergic therapy is essential in preventing hypertensive crises in patients with malignant pheochromocytoma undergoing CVD treatment.

Seminoma of the testis presenting as an ulcerating mass of the duodenum

Germ cell tumors (GCT) arising in the testes secondarily involve bowel in 5% of patients (1), and such involvement is usually via extension from adjacent metastatic lymphadenopathy. While this involvement often causes obstruction and gastrointestinal bleeding, radiologic identification of bowel ulceration has not been reported. We report an unusual case of small bowel invasion and ulceration, identified on CT examination, due to adenopathy resulting from testicular carcinoma.

Evidence suggesting a role for cathepsin L in an experimental model of glomerulonephritis

We have utilized specific, irreversible inhibitors of cysteine proteinases to examine the role of renal cathepsin B and cathepsin L in the proteinuria which occurs in an experimental model of human glomerular disease. Administration of trans-epoxysuccinyl-L-leucylamido-(3-methyl)butane (Ep475) a specific, irreversible inhibitor of cysteine proteinases, including cathepsins B and L, significantly reduced proteinuria in rats with experimentally induced, neutrophil-independent, anti-GBM antibody disease (controls: 10 +/- 1 mg/24 h, N = 8; anti-GBM antibody disease: 203 +/- 30 mg/24 h, N = 8; anti-GBM antibody disease + Ep475: 112 +/- 13 mg/24 h, mean +/- SEM, N = 6, P less than 0.05). There was a marked reduction in the activity of both cathepsin B and cathepsin L in renal cortices obtained from Ep475-treated rats compared to either saline-treated controls or rats treated with anti-GBM IgG only. Administration of Z-Phe-Tyr(O-t-butyl)CHN2, a specific, irreversible cysteine proteinase inhibitor with a high degree of selectivity toward cathepsin L, also caused a reduction in anti-GBM antibody-induced proteinuria (90 +/- 18 mg/24 h, N = 6, P less than 0.05). This reduction in proteinuria was accompanied by a marked decrease (-84%) in the specific activity of renal cortical cathepsin L in Z-Phe-Tyr(O-t-butyl)CHN2-treated rats. However, cathepsin B activity was unchanged. There was no significant change in the renal anti-GBM antibody uptake, plasma urea nitrogen, or plasma creatinine values in the Z-Phe-Tyr(O-t-butyl)CHN2-treated rats compared to rats treated with anti-GBM IgG only or saline-treated controls. These data document the ability of cysteine proteinase inhibitors to decrease the proteinuria which occurs in a neutrophil-independent model of human anti-GBM antibody disease and suggest an important role for cathepsin L in the pathophysiology of the proteinuria which occurs in this model.

Elevated expression of c-myc proto-oncogene in scleroderma fibroblasts

Scleroderma is a connective tissue disease characterized by the overproduction of extracellular matrix components. The mechanisms of fibrosis may involve increased fibroblast proliferation in the scleroderma lesion due to the presence of cells with abnormal growth properties, in addition to the well-known over-production of several matrix components. The c-myc proto-oncogene has been implicated in dysregulation of cell growth in neoplastic cells and as an essential element of the response to growth factors in normal cells. Therefore, to investigate the molecular basis of growth in scleroderma, we compared expression of c-myc gene in scleroderma and control cells. In this report, we show that under low serum conditions (1% serum), scleroderma fibroblasts express 2.5-3 higher level of c-myc message. Moreover, stimulation of c-myc after addition of fresh 10% serum is blunted in scleroderma compared to control cells. Observed c-myc expression in scleroderma is similar to c-myc expression in transformed cells. In addition, there is also increased proliferation of scleroderma cells in 1% serum as measured directly by a nuclear label assay. These data suggest the presence of fibroblasts with abnormal growth properties in the scleroderma lesion.

The cysteine proteinase inhibitor, E-64, reduces proteinuria in an experimental model of glomerulonephritis

Proteinuria is a major manifestation of glomerular disease (glomerulonephritis, GN). We examined the effect of trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E-64), a specific and irreversible cysteine proteinase inhibitor, on urinary protein excretion in a complement- and neutrophil-independent model of antiglomerular basement membrane (GBM) antibody disease. A single injection of rabbit antirat-GBM IgG produced a marked increase in urinary protein excretion 24hr after injection. In two separate studies using different pools of antiGBM IgG, administration of E-64 (5mg every 6h starting 2hr prior to induction of GN) reduced proteinuria (-45 +/- 7%, and -41 +/- 14%, Mean +/- SEM, n = 6; P less than 0.001) in the 24 hour period following induction of the disease. This reduction in urinary protein excretion was accompanied by a marked decrease in the specific activity of the cysteine proteinases cathepsins B and L in glomeruli (B: -97%; L: -84%) and renal cortex (B: -87%; L: -75%) isolated from the same E-64-treated rats compared to same saline-treated controls. These data, combined with the specificity of E-64 for cysteine proteinases, suggest a potential role for cysteine proteinases in the increased GBM permeability and proteinuria in this experimental model of glomerular disease.

Use of slow Ca2+ channel blockers to enhance inhibition by taxol of growth of drug-sensitive and -resistant Chinese hamster ovary cells

The toxicity of taxol for drug-sensitive and -resistant Chinese hamster ovary cells has been examined in tissue cultures in the presence and absence of drugs that are being used as slow Ca2+ channel blockers. Enhancement of toxicity was found to be greater in the case of taxol than of daunorubicin. Several blockers including pimozide and nimodipine were more effective as toxicity enhancers than verapamil. Studies of uptake of 14C-labeled daunorubicin revealed a poor correlation between the effectiveness of various drugs to enhance intracellular daunorubicin concentration and their toxicity to cells grown in tissue cultures.