Organization of human ACAT-2 gene and its cell-type-specific promoter activity

Acyl-CoA:cholesterol acyltransferase (ACAT) plays important roles in cellular cholesterol homeostasis. Two ACAT genes exist in mammals. We report here the genomic organization of human ACAT-2 gene and analysis of its promoter activity in various cell lines. The human ACAT-2 gene spans over 18 kb and contains 15 exons. Three transcription start sites and one poly(A) site are identified by the 5'/3'-RACE. In addition, the human ACAT-2 gene is linked to the insulin-like growth factor binding protein 6 (IGFBP-6) gene in a head-to-tail manner with a small intergenic region of about 1.2 kb. The 5'-flanking region of human ACAT-2 gene contains many potential cis-acting elements for multiple transcriptional regulatory factors but lacks TATA and CCAAT boxes. Using promoter-luciferase reporter assays, we demonstrate the transcriptional activity of ACAT-2 gene promoter is high in Caco-2 cells, especially after these cells become postconfluent and behave as intestinal enterocytes.

Mechanism of high susceptibility of iron-overloaded mouse to Vibrio vulnificus infection

Vibrio vulnificus produces fulminant septicemia in humans with underlying conditions, particularly those with diseases that elevate the iron level. The effect of a high iron level on the virulence of V. vulnificus was therefore investigated in mice treated with iron dextran. The mice loaded with iron became highly susceptible to V. vulnificus infection, the LD50 (50% lethal dose) decreased five logs when infected per peritoneum. However, when infected via the oral route, the LD50 was affected little unless the mouse was treated with an additional drug such as cyclophosphamide or D-galactosamine. Mice with or without iron-overloading died when the bacterial concentration in the blood reached 10(5) cfu/ml or above. Iron increased the growth rate of the bacteria, both inside and outside of the animal, quickly reaching a lethal concentration in the iron-overloaded mouse. V. vulnificus, grown with or without the addition of iron, showed strong cytotoxicity on the isolated cells or within the animal at high bacterial concentration. Iron overload stimulated the production of tumor necrosis factor alpha (TNF-alpha), a major factor of septic shock, in mice upon infection with the bacteria, probably caused by the endotoxin; however, the neutrophils, whose migration is effected by TNF-alpha, appeared to be less active. Taken together, the major virulence factor of V. vulnificus appeared to be the accelerated growth of bacteria to quickly reach the lethal level and the lower activity of immune cells including neutrophil as a result of iron-overloading. These two effects manifest other virulence factors, the host's as well as bacterial. Such factors, other than TNF-alpha stimulated by the endotoxin, enhanced cytotoxicity, which kills the host cells including the host's immune cells.

Thickened pituitary stalk with central diabetes insipidus: report of three cases

Diabetes insipidus of central origin usually results from lesions in the hypothalamic neurohypophyseal system. Lymphocytic infundibuloneurohypophysitis is an uncommon cause. Cases of lymphocytic infundibuloneurohypophysitis with thickening of the pituitary stalk and enlargement of the neurohypophysis with no hyperintense signal in the posterior pituitary have been reported. Reported cases presenting with isolated thickening of the pituitary stalk are very rare. We report three such cases, one in a nulliparous woman and the other two in men. Magnetic resonance (MR) imaging in these patients revealed isolated thickening of the pituitary stalk, loss of the hyperintense signal of the posterior pituitary, and an adenohypophysis of normal size. All cases had abnormal nodular infundibular enlargement. One male patient had hypogonadism; the other patients showed no sign of adenohypophyseal deficiency on stimulation test. Serial follow-up MR imaging revealed that all three patients had persistent thickening of the pituitary stalk. Diabetes insipidus was controlled by the administration of desmopressin acetate in all patients.

Prenatal diagnosis of oculocutaneous albinism two mutations located at the same allele

A pregnant woman accepted amniocentesis on account of the previous birth of type 1 oculocutaneous albinism (OCA1). PCR revealed that the fetus had two mutations (862delTT, Arg 299His). The father had one missense mutation (Arg 299Ser) and the mother had the same mutations as the fetus. Two mutations of the fetus located at the same allele were suspected. Postpartal follow-up confirmed his carrier status. For recessive disorders, faced with a fetus with two mutations, the importance of performing segregation analysis of mutation on both parents is emphasized. This could exclude two mutations located at the same allele and prevent the unnecessary termination of a fetus with carrier status.

Molecular cloning and functional characterization of a novel delayed rectifier potassium channel from channel catfish (Ictalurus punctatus): expression in taste buds

The gustatory system of channel catfish is widely studied for its sensitivity to amino acids. As a first step in identifying the molecular components that play a role in taste transduction in catfish, we cloned the full-length cDNA for Kv2-catfish, a novel K(+) channel that is expressed in taste buds. The deduced amino acid sequence is 816 residues, and shares a 56-59% sequence identity with Kv2.1 and Kv2.2, the other members of the vertebrate Kv2 subfamily of voltage-gated K(+) channels. The Kv2-catfish RNA was expressed in taste buds, brain, skeletal muscle, kidney, intestine and gills, and its gene is represented as a single copy in the catfish genome. Recombinant channels expressed in Xenopus oocytes were selective for K(+), and were inhibited by tetraethylammonium applied to the extracellular side of the membrane during two-electrode voltage clamp analysis with a 50% inhibitory constant of 6.1 mM. The channels showed voltage-dependent activation, and did not inactivate within 200 ms. Functionally, Kv2-catfish is a voltage-gated, delayed rectifier K(+) channel, and its primary structure is the most divergent sequence identified among the vertebrate members of the Kv2 subfamily of K(+) channels, being related equally well to Kv2.1 and Kv2.2.

Legionnaires' disease in a patient with rheumatoid arthritis

A 62-year-old male with rheumatoid arthritis (RA) who was taking nonsteroid anti-inflammatory drug for controlling synovitis developed a flare of his arthritis, hepatitis, and pneumonia due to infection with Legionella pneumophila serotype 1. Adult respiratory distress syndrome (ARDS) occurred following the development of pneumonia. After the introduction of erythromycin and ventilator support with positive end expiratory pressure (PEEP), his condition stabilized and he recovered gradually. We suggest that L. pneumophila should be considered early in the differential diagnosis of pneumonia in RA patients due to their immunocompromised status.

Transurethral microwave thermotherapy for symptomatic benign prostatic hyperplasia: short-term experience with Prostcare

PURPOSE

To assess our short-term experience with transurethral microwave thermotherapy (TUMT) for symptomatic benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

From August 1993 through July 1994, in total 65 patients with symptomatic BPH were enrolled into this study. The patients' ages ranged from 56 to 95 years with a mean of 70 years. Under local anesthesia with intraurethral instillation of Xylocaine jelly only, all patients received one session of TUMT for up to 60 min with Prostcare equipment. Uroflowmetry was performed and international prostatic symptom score (IPSS) determined before 3 and 6 months after TUMT for assessment of efficacy. All adverse events were recorded and evaluated for clinical relevance.

RESULTS

At 3 and 6 months following TUMT, the mean IPSS decreased from 19.7 +/- 6.8 (baseline) to 12.8 +/- 8.2 (-46%) and to 15.5 +/- 9.0 (-21%), respectively; the maximal urine flow rate at 3 and 6 months increased from 9.1 +/- 4.8 ml/s (baseline) to 11.0 +/- 4.9 ml/s (+21%) and to 10.9 +/- 5.6 ml/s (+19%), respectively. During TUMT, burning sensation was the most frequent complaint (38.5%), followed by urethral discomfort (29.2%) and urgency (9.2%). Two patients (3.1%) interrupted TUMT, because of intolerable pain. Following TUMT micturition pain (73.8%) and gross hematuria (45.9%) were the most adverse events. Most of these adverse events disappeared within 2 weeks. One patient suffered from skin erosion over the penoscrotal junction 1 week later. None had retrograde ejaculation; 1 patient complained of erectile dysfunction.

CONCLUSION

Although the efficacy of TUMT with Prostcare became less prominent 6 months after TUMT, TUMT was still a tolerable, safe alternative treatment of BPH, especially in patients who were not suitable for transurethral resection of the prostate or anesthesia.

Longitudinal survey of blood flow at three different locations in the middle cerebral artery in normal fetuses

OBJECTIVES

To assess vascular impedance at three different locations in the middle cerebral artery (MCA) in normal fetuses throughout gestation.

MATERIALS AND METHODS

Uncomplicated singleton pregnancies at 15-40 weeks' gestation in which Doppler surveys of both MCAs could be obtained were recruited. The pulsatility index (PI) and resistance index (RI) of the proximal, mid and distal sites of both MCAs were measured. The five gestation periods at which the Doppler surveys were performed were (i) 15-19 completed weeks; (ii) 20-24 completed weeks; (iii) 25-29 completed weeks; (iv) 30-34 completed weeks; (v) 35-39 completed weeks.

RESULTS

A total of 42 fetuses were recruited. The average PI/RI values of the proximal, mid and distal MCA were 1.61/0.82, 1.77/0.82, and 1.84/0.84, respectively. The PI value of the proximal MCA was lower than that of the mid and distal MCA. The PI values of the mid and distal MCA showed no difference. The RI value of the MCA from the three locations also showed no difference. The PI/RI values of MCA for each gestational phase were: (i) 1.81/0.87; (ii) 1.79/0.86; (iii) 1.78/0.86; (iv) 1.70/0.81; (v) 1.62/0.77, respectively. Decreased PI/RI values were observed after 30 weeks' gestation.

CONCLUSIONS

The PI values of the proximal MCA are lower than those of the mid and distal MCA. A marked decrease in PI/RI values was observed after 30 weeks' gestation.

Induction of acyl-coenzyme A:cholesterol acyltransferase-1 by 1,25-dihydroxyvitamin D(3) or 9-cis-retinoic acid in undifferentiated THP-1 cells

We have previously shown that acyl-coenzyme A: cholesterol acyltransferase-1 (ACAT-1) protein content increases significantly during the human monocyte-macrophage differentiation process. To gain further insight, we used undifferentiated human monocytic THP-1 cells as a model system with which to examine whether ACAT-1 mRNA and protein content can be increased by treating cells with 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] or with 9-cis-retinoic acid (9-cis-RA), two agents known to upregulate the expression of various genes during the monocyte-macrophage differentiation process. Immunoblot analysis with anti-human ACAT-1 antibodies revealed that ACAT-1 protein was increased by 2.6-fold, using 1,25-(OH)(2)D(3) at a physiological concentration (100 pM). ACAT-1 protein was also increased when using 9-cis-RA, but only at relatively high concentrations (0.1;-1 microM). Northern blot analysis revealed that among the four ACAT-1 mRNA transcripts (2.8, 3.6, 4.2, and 7.0 kb) examined, only the 2.8- and 3.6-kb transcripts were selectively increased. On the basis of enzyme assays in vitro, ACAT activity was increased 3.0-fold by using 100 nM 1,25-(OH)(2)D(3), and 1.8-fold by using 1 microM 9-cis-RA. Together, our results suggest that 1,25-(OH)(3) participates in ACAT-1 gene expression during the monocyte-macrophage differentiation process.

Probing the structural diversities of long alpha-neurotoxins by fluorescence quenching studies

Trp fluorescence of Ophiophagus hannah neurotoxins (Oh-4, Oh-6A, Oh-7, and Oh-8) and Bungarus multicinctus (alpha-bungarotoxin was quenched by acrylamide and iodide. Acrylamide quenching studies indicated that the degree of exposure of Trp residues in the neurotoxins followed the order Oh-8 > Oh-7 > Oh-6A > Oh-4 > alpha-bungarotoxin, as did the accessibility for iodide. These results reveal that the exposed degree of Trp residues and the microenvironment surrounding Trp residues in the neurotoxins differ, even though their Trp residues and positively charged residues are located at the same or homologous positions. In contrast to unfolded Oh-4, Oh-6A, Oh-7, and alpha-bungarotoxin, unfolding of Oh-8 by reduction and S-carboxymethylation caused a notable decrease in the susceptibility of their Trp residues for iodide. These observations support the view that the side chains of Trp residues and positively charged residues in their native structure do not point toward the same spatial positions. Computer models of the neurotoxins are in good agreement with this proposition. These results elucidate why the conserved Trp residues and cationic groups do not always play the same roles in the biological activities of the neurotoxins.

Mixed-effects models for the evaluation of long-term trends in exposure levels with an example from the nickel industry

Longitudinal studies play an important role in evaluating the temporal behavior of occupational exposures. The purpose of this paper is to examine certain features of longitudinal data and to present a general conceptual framework by which these features may be taken into account so that statistically valid inferences can be made. Statistical methods that rely on the application of mixed-effects models are proposed for evaluating long-term trends in exposures to workplace contaminants. The mixed-effects model presented herein has fixed effects for trend components and random effects for workers, job groups, buildings and plants. These models differ from conventional techniques in that they accommodate hierarchically structured data and account for the correlation that may arise due to the clustering of measurements based on when and where the data were collected. While primary interest is focused on determining the magnitude of trends in exposure levels over time, the model also provides information about the magnitude of the sources of variation associated with different groupings of workers. Application of the mixed-effects model is illustrated with a large database of shift-long personal exposure measurements collected on workers exposed to nickel aerosols in the nickel-producing industry.

Value of ICD-9 coded chief complaints for detection of epidemics

To assess the value of ICD-9 coded chief complaints for early detection of epidemics, we measured sensitivity, positive predictive value, and timeliness of Influenza detection using a respiratory set (RS) of ICD-9 codes and an Influenza set (IS). We also measured inherent timeliness of these data using the cross-correlation function. We found that, for a one-year period, the detectors had sensitivity of 100% (1/1 epidemic) and positive predictive values of 50% (1/2) for RS and 25% (1/4) for IS. The timeliness of detection using ICD-9 coded chief complaints was one week earlier than the detection using Pneumonia and Influenza deaths (the gold standard). The inherent timeliness of ICD-9 data measured by the cross-correlation function was two weeks earlier than the gold standard.

Renormalization group analysis for thermal turbulent transport

In this study, we continue with our previous renormalization group analysis of incompressible turbulence, aiming at determination of various thermal transport properties. In particular, the temperature field T is considered a passive scalar. The quasinormal approximation is assumed for the statistical correlation between the velocity and temperature fields. A differential argument leads to derivation of the turbulent Prandtl number Pr(t) as a function of the turbulent Peclet Pe(t) number, which in turn depends on the turbulent eddy viscosity nu(t). The functional relationship between Pr(t) and Pe(t) is comparable to that of Yakhot et al. [Int. J. Heat Mass Transf. 30, 15 (1987)] and is in close consistency with direct-numerical-simulation results as well as measured data from experiments. The study proceeds further with limiting the operation of renormalization group analysis, yielding an inhomogeneous ordinary differential equation for an invariant thermal eddy diffusivity sigma. Simplicity of the equation renders itself a closed-form solution of sigma as a function of the wave number k, which, when combined with a modified Batchelor's energy spectrum for the passive temperature T, facilitates determination of the Batchelor constant C(B) and a parallel Smagorinsky model and the model constant C(P) for thermal turbulent energy transport.

Spinal leptomeningeal metastases of giant cell glioblastoma associated with subarachnoid haemorrhage: case report

A case of subarachnoid haemorrhage (SAH) due to spinal leptomeningeal metastases of a giant cell glioblastoma is described. A 51 year old male presented with a four week history of headache. Neurological examination was normal except for a slight left hemiparesis. Computed tomography (CT) revealed a large cyst with a mural nodule in the right temporal lobe. The tumour was removed followed by 60 Gy of radiation therapy. Thirty-two months later he developed headache and shoulder pain with symptoms of normal pressure hydrocephalus. Head CT showed ventriculomegaly and SAH. Magnetic resonance imaging showed spinal leptomeningeal metastases at the C4-5, T12, and L2 levels, but no local recurrence or tumour dissemination in the brain. He died 34 months after surgery. Autopsy revealed diffuse SAH over the whole brain and spinal cord, associated with spinal leptomeningeal metastases, but no cerebral aneurysms. Spinal radiotherapy and ventriculoperitoneal shunting could possibly have extended survival in this patient.

A human breast epithelial cell type with stem cell characteristics as target cells for carcinogenesis

Two types of human breast epithelial cells (HBEC) have been characterized. In contrast to Type II HBEC, which express basal epithelial cell phenotypes, Type I HBEC are deficient in gap junctional intercellular communication and are capable of anchorage-independent growth and of expressing luminal epithelial cell markers, estrogen receptors, and stem cell characteristics (i.e. the ability to differentiate into other cell types and to form budding/ductal organoids on Matrigel). A comparative study of these two types of cells has revealed a high susceptibility of Type I HBEC to immortalization by SV40 large T antigen, although both types of cells are equally capable of acquiring an extended life span (bypassing senescence) after transfection with SV40. The immortalization was accompanied by elevation of a low level of telomerase activity in the parental cells after mid-passage ( approximately 60 cumulative population doubling levels). Thus HBEC do have a low level of telomerase activity, and Type I HBEC with stem cell characteristics are more susceptible to telomerase activation and immortalization, a mechanism which might qualify them as target cells for breast carcinogenesis. The immortalized Type I HBEC can be converted to highly tumorigenic cells by further treatment with X rays (2 Gy x 2) and transfection with a mutated ERBB2 (also known as NEU) oncogene, resulting in the expression of p185(ERBB2) which is tyrosine phosphorylated.

Role of stem cells and gap junctional intercellular communication in human carcinogenesis

Epidemiological data, experimental animal bioassays, studies of in vitro neoplastic transformation, and molecular oncology studies have implicated a multistage, multimechanism process in human carcinogenesis. From animal carcinogenesis studies, the operational concept of a single normal cell being irreversibly altered during the first step in carcinogenesis is called initiation. The subsequent interruptible or reversible clonal expansion of these initiated cells by non-cytotoxic mitogenic stimuli, compensatory hyperplasia due to cell death by necrosis, or inhibition of apoptosis is referred to as the promotion phase. Last, when one of these clonally expanded, initiated cells acquires sufficient genetic/epigenetic alterations to become neoplastically transformed and acquire the phenotypes of promoter independence, invasiveness and metastasis, it is referred to as the progression step of carcinogenesis. This report hypothesizes that the single normal cell that is initiated is a pluripotent stem cell. By assuming that the normal pluripotent stem cell is immortal and becomes mortal when induced to terminally differentiate, initiation would be viewed as the irreversible process by which a stable alteration in a finite number of proto-oncogenes and/or tumor suppressor genes could block terminal differentiation or "mortalization". Promotion would involve the reversible inhibition of gap junctional intercellular communication (GJIC) and while progression occurs with the stable down-regulation of GJIC.

Antigenic specificity of anti-neutrophil cytoplasmic antibody

PURPOSE

To determine the antigens recognized by sera containing classic anti-neutrophil cytoplasmic antibodies (c-ANCAs) and perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCAs).

METHODS

A total of 160 serum samples (all from a reference laboratory) that were originally collected from different clinics for ANCA tests were examined for c-ANCA and p-ANCA by indirect immunofluorescence (IIF). All positive sera were further tested for reactivity to proteinase 3 (PR3), myeloperoxidase (MPO), lactoferrin (LF), and lysozyme (LZ) by enzyme-linked immunosorbent assay (ELISA). In addition, sera from 110 patients with systemic lupus erythematosus (SLE), 51 patients with rheumatoid arthritis (RA), and 40 healthy subjects were also tested for reactivity to these antigens.

RESULTS

HF detected ANCA in 81 (51%) of the 160 clinical serum samples. Of these 81 serum samples, 21 (26%) contained c-ANCA and 60 (74%) contained p-ANCA. P-ANCA was more commonly found in antinuclear antibody (ANA)-positive sera than in ANA-negative sera (p < 0.01). Of the 21 serum samples positive for c-ANCA, 12 (57%) reacted to PR3, four (19%) to LF, four (19%) to LZ, and three (14%) to MPO on ELISA. By contrast, of the 60 sera positive for p-ANCA, 15 (25%) reacted to MPO, 13 (22%) to PR3, eight (13%) to LF, and four (7%) to LZ. The prevalence of ANCA specificities in serum samples from SLE patients were as follows: anti-PR3, 0%; anti-MPO, 1%; anti-LF, 27%; and anti-LZ, 29%. The prevalence of ANCA specificities in serum samples from RA patients were as follows: anti-PR3, 6%; anti-MPO, 2%; anti-LF, 8%; anti-LZ, 4%.

CONCLUSION

Sera positive for c-ANCA and p-ANCA reacted to diverse cytoplasmic antigens from neutrophils. P-ANCA was found in 55% of ANA-positive serum samples. LF and LZ were most commonly found in serum samples from patients with SLE.

Leukocyte chemosensory migration on vascular prosthetic biomaterial is mediated by an integrin beta2 receptor chain

The ability of adherent activated leukocytes to migrate on implanted prosthetic biomaterial surfaces may be an early rate-limiting step in eliminating periprosthetic infection. The goal of this study was to explore the molecular mechanism governing leukocyte migration on the implantable cardiovascular prosthetic biomaterial, expanded polytetrafluoroethylene (ePTFE), in response to stimulation by the soluble chemokine, N-formyl-methionyl-leucyl-phenylalanine (fMLP). We used a population level migration assay to study the migration of polymorphonuclear leukocytes (PMN) on ePTFE, overlaid by a gelatin/agar composite. A theoretical random walk model was applied to describe fMLP-induced PMN migration on ePTFE in terms of an objective random cell migration coefficient, mu. Our results show that following stimulation with 0-10(-7) M fMLP, the value of mu ranged from 5.43 x 10(-9) to 1.08 x 10(-7) cm2/s, with a maximum value obtained at 10(-8) M fMLP. We probed the expression levels of various beta2 integrin receptor subunits and their contribution to the migratory function of ePTFE-adherent PMN over a wide range of fMLP concentration. We found that the expression of the integrin beta-chain, CD18, was also maximized at 10(-8) M fMLP, along with only slight changes in the expression of integrin alpha-chains (CD11a,b,c). We report that treatment with antibodies against either beta or combined alpha chains, but not individual alpha chains, inhibited PMN attachment to ePTFE at 10(-8) M fMLP, suggesting the likely role of combined beta2 receptor subunits in early adhesion events following stimulation. However, treatment with only anti-CD18 significantly lowered PMN migration on ePTFE (mu = 5.98 x 10(-9) cm2/s), and this degree of inhibition was much greater than that elicited by the combined treatment with antibodies recognizing all possible alpha-chains. Overall, we conclude that migratory behavior of chemokinetically stimulated PMN on ePTFE is mediated by the integrin beta chain pool, and is only weakly regulated by the integrin alpha chain.

Immunophenotypic profile of myeloid cells in granulocytic sarcoma by immunohistochemistry. Correlation with blast differentiation in bone marrow

The present study was designed to evaluate the lineage differentiation (particularly monocytic differentiation) of immature myeloid cells in granulocytic sarcoma (GS) by immunohistochemistry and correlate the results with lineage differentiation of blasts in the bone marrow and to determine the degree of maturation of the infiltrating myeloid cells in GS by immunohistochemistry using CD34 and HLA-DR. Immunohistochemical stains were performed on paraffin-embedded tissue from 17 GS lesions with lineage-associated markers: myeloperoxidase, CD68 (KP1), CD68 (PG-Ml), glycophorin A, factor VIII, and CD56; and with markers for blasts and immature myeloid cells: CD34 and HLA-DR. Our results show that positive staining with PG-M1, but not KP1, suggests monocytic differentiation of myeloid cells in GS and correlates with the monocytic differentiation of blasts in the bone marrow. Expression of CD56 is frequent in GS, especially when the marrow blasts have monocytic differentiation, and should not be interpreted as a primary natural-killer cell process. The immature myeloid cells in GS are frequently HLA-DR positive. However, CD34 positivity of the immature myeloid cells is relatively uncommon, except in cases with underlying myelodysplastic syndrome or chronic myelogenous leukemia.

Coyotes (Canis latrans) as the reservoir for a human pathogenic Bartonella sp.: molecular epidemiology of Bartonella vinsonii subsp. berkhoffii infection in coyotes from central coastal California

Bartonella vinsonii subsp. berkhoffii was originally isolated from a dog suffering infectious endocarditis and was recently identified as a zoonotic agent causing human endocarditis. Following the coyote bite of a child who developed clinical signs compatible with Bartonella infection in Santa Clara County, Calif., this epidemiological study was conducted. Among 109 coyotes (Canis latrans) from central coastal California, 31 animals (28%) were found to be bacteremic with B. vinsonii subsp. berkhoffii and 83 animals (76%) had B. vinsonii subsp. berkhoffii antibodies. These findings suggest these animals could be the wildlife reservoir of B. vinsonii subsp. berkhoffii. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the gltA and 16S rRNA genes for these 31 isolates yielded similar profiles that were identical to those of B. vinsonii subsp. berkhoffii. Partial sequencing of the gltA and 16S rRNA genes, respectively, indicated 99.5 and 100% homology between the coyote isolate and B. vinsonii subsp. berkhoffii (ATCC 51672). PCR-RFLP analysis of the 16S-23S intergenic spacer region showed the existence of two different strain profiles, as has been reported in dogs. Six (19%) of 31 Bartonella bacteremic coyotes exhibited the strain profile that was identified in the type strain of a canine endocarditis case (B. vinsonii subsp. berkhoffii ATCC 51672). The other 25 bacteremic coyotes were infected with a strain that was similar to the strains isolated from healthy dogs. Based on whole bacterial genome analysis by pulsed-field gel electrophoresis (PFGE) with SmaI restriction endonuclease, there was more diversity in fingerprints for the coyote isolates, which had at least 10 major variants compared to the two variants described for domestic dog isolates from the eastern United States. By PFGE analysis, three Bartonella bacteremic coyotes were infected by a strain identical to the one isolated from three healthy dog carriers. Further studies are necessary to elucidate the mode of transmission of B. vinsonii subsp. berkhoffii, especially to identify potential vectors, and to determine how humans become infected.

Methods of cytologic smear preparation and fixation. Effect on the immunoreactivity of commonly used anticytokeratin antibody AE1/AE3

OBJECTIVE

To evaluate the effect of fixation and methods of cytologic smear preparation on the immunoreactivity of commonly used anticytokeratin antibody AE1/AE3.

STUDY DESIGN

Scrape cytology smears and formalin-fixed, paraffin-embedded tissue sections (FPTS) of 20 unfixed, fresh specimens submitted for intraoperative consultation were studied by the immunoperoxidase method. In addition to the morphologic examination, the smears and FPTS were evaluated for intensity and proportion scores. For each specimen, two scrape cytology smears were wet fixed in 95% ethanol, and 12 smears were air dried without fixation. Air-dried smears were either postfixed after rehydration in saline or fixed directly without rehydration by one of the three fixatives: alcoholic formalin, 95% ethanol with 5% acetic acid or 95% ethanol.

RESULTS

Both intensity and proportion scores were higher with rehydrated, air-dried smears as compared to those without rehydration and were comparable to those with wet-fixed smears and FPTS. In the rehydrated group, the optimum results were achieved when the smears were postfixed with alcoholic formalin.

CONCLUSION

The method of preparation and fixation had variable effects on the immunoreactivity of anticytokeratin antibody AE1/AE3. The optimum results were achieved with saline-rehydrated, air-dried smears post-fixed in alcoholic formalin. To evaluate the role of inter-sample variation, further, larger studies are recommended on this and other antibodies before applying them to different types of cytologic smears.

Canal-wall-down tympanoplasty with mastoidectomy for advanced cholesteatoma

OBJECTIVE

The objective of this study was to review 8.5 years of the senior author's experience with canal-wall-down mastoid surgery for extensive cholesteatoma with high-grade atelectasis and severely destructed ossicles.

DESIGN

A retrospective review was conducted.

SETTING

The setting was a tertiary care medical centre.

METHODS

Available records consulted included 104 canal-wall-down mastoidectomy for advanced-stage cholesteatomas between July 1984 and December 1992.

MAIN OUTCOME MEASURES

Recurrence, hearing results, and dry ear rate were analyzed.

RESULTS

The recurrence rate was 4 of 104 (3.8%), and 9.6% of subjects suffered from recurrent otorrhea. Thirty-seven of 104 (35.6%) achieved the closure of air-bone gap within 20 dB. The availability of stapes suprastructure influenced the postoperative hearing level significantly (p < .001).

CONCLUSION

Even in treating advanced cholesteatoma, canal-wall-down mastoidectomy provides a low recurrence rate, establishes a high dry ear rate, and preserves adequate hearing when the stapes suprastructure is available for reconstruction.

Effect of electromagnetic field exposure on chemically induced differentiation of friend erythroleukemia cells

Whether exposure of humans to extremely low frequency electromagnetic fields (ELF-EMF) can cause cancer is controversial and therefore needs further research. We used a Friend erythroleukemia cell line that can be chemically induced to differentiate to determine whether ELF-EMF could alter proliferation and differentiation in these cells in a manner similar to that of a chemical tumor promoter. Exposure of this cell line to 60 Hz ELF-EMF resulted in a dose dependent inhibition of differentiation, with maximal inhibition peaking at 40% and 40 mG (4 microT). ELF-EMF at 10 mG (1.0 microT) and 25 mG (2.5 microT) inhibited differentiation at 0 and 20%, respectively. ELF-EMF at 1.0 (100) and 10.0 G (1,000 microT) stimulated cell proliferation 50% above the sham-treated cells. The activity of telomerase, a marker of undifferentiated cells, decreased 100[times] when the cells were induced to differentiate under sham conditions, but when the cells were exposed to 0.5 G (50 microT) there was only a 10[times] decrease. In summary, ELF-EMF can partially block the differentiation of Friend erythroleukemia cells, and this results in a larger population of cells remaining in the undifferentiated, proliferative state, which is similar to the published results of Friend erythroleukemia cells treated with chemical-tumor promoters.

Monocyte-derived CD1a+ and CD1a- dendritic cell subsets differ in their cytokine production profiles, susceptibilities to transfection, and capacities to direct Th cell differentiation

We describe a phenotypically and functionally novel monocyte-derived dendritic cell (DC) subset, designated mDC2, that lacks IL-12 synthesis, produces high levels of IL-10, and directs differentiation of Th0/Th2 cells. Like conventional monocyte-derived DC, designated mDC1, mDC2 expressed high levels of CD11c, CD40, CD80, CD86, and MHC class II molecules. However, in contrast to mDC1, mDC2 lacked expression of CD1a, suggesting an association between cytokine production profile and CD1a expression in DC. mDC2 could be matured into CD83+ DC cells in the presence of anti-CD40 mAbs and LPS plus IFN-gamma, but they remained CD1a- and lacked IL-12 production even upon maturation. The lack of IL-12 and CD1a expression by mDC2 did not affect their APC capacity, because mDC2 stimulated MLR to a similar degree as mDC1. However, while mDC1 strongly favored Th1 differentiation, mDC2 directed differentiation of Th0/Th2 cells when cocultured with purified human peripheral blood T cells, further indicating functional differences between mDC1 and mDC2. Interestingly, the transfection efficiency of mDC2 with plasmid DNA vectors was significantly higher than that of mDC1, and therefore mDC2 may provide improved means to manipulate Ag-specific T cell responses after transfection ex vivo. Taken together, these data indicate that peripheral blood monocytes have the capacity to differentiate into DC subsets with different cytokine production profiles, which is associated with altered capacity to direct Th cell differentiation.

On-line monitoring trihalomethanes in chlorinated water by membrane introduction-fast gas chromatography mass-spectrometry

An analytical method based on membrane introduction and fast gas chromatography-mass spectrometry (GC-MS) has been developed for the on-line monitoring of trihatomethanes (THMs) in chlorinated drinking water. The coupling of membrane introduction with fast GC-MS offers the advantage of membrane introduction as an on-line sampling device and fast GC-MS as a separation and identification method. While maintaining the on-line monitoring characteristic of traditional membrane introduction mass spectrometry (MIMS), the difficulty of distinguishing CHCl3 and CHBrCl2 in MIMS was overcome by rapid GC separation and MS analysis. Water permeated across the membrane affected the analysis of CHBr2Cl and CHBr3. A method based on controlling the injection temperature and injection time has been developed to overcome the moisture problem. This method is simple and less time consuming than the conventional moisture removing method. Under typical operating conditions, the sampling rate was about 20 samples h(-1) capable of on-line monitoring THMs in chlorinated drinking water. The detection limits of this system were found to be about 2 ppt, 4 ppt, 4 ppt, and 8 ppt for CHCl3 CHBrCl2, CHBr2Cl, and CHBr3, respectively.

Immunological quantitation and localization of ACAT-1 and ACAT-2 in human liver and small intestine

By using specific anti-ACAT-1 antibodies in immunodepletion studies, we previously found that ACAT-1, a 50-kDa protein, plays a major catalytic role in the adult human liver, adrenal glands, macrophages, and kidneys but not in the intestine. Acyl-coenzyme A:cholesterol acyltransferase (ACAT) activity in the intestine may be largely derived from a different ACAT protein. To test this hypothesis, we produced specific polyclonal anti-ACAT-2 antibodies that quantitatively immunodepleted human ACAT-2, a 46-kDa protein expressed in Chinese hamster ovary cells. In hepatocyte-like HepG2 cells, ACAT-1 comprises 85-90% of the total ACAT activity, with the remainder attributed to ACAT-2. In adult intestines, most of the ACAT activity can be immunodepleted by anti-ACAT-2. ACAT-1 and ACAT-2 do not form hetero-oligomeric complexes. In differentiating intestinal enterocyte-like Caco-2 cells, ACAT-2 protein content increases by 5-10-fold in 6 days, whereas ACAT-1 protein content remains relatively constant. In the small intestine, ACAT-2 is concentrated at the apices of the villi, whereas ACAT-1 is uniformly distributed along the villus-crypt axis. In the human liver, ACAT-1 is present in both fetal and adult hepatocytes. In contrast, ACAT-2 is evident in fetal but not adult hepatocytes. Our results collectively suggest that in humans, ACAT-2 performs significant catalytic roles in the fetal liver and in intestinal enterocytes.

Leukemia inhibitory factor expression in different endometrial locations between fertile and infertile women throughout different menstrual phases

PURPOSE

The purpose was to demonstrate the leukemia inhibitory factor (LIF) expression in different endometrial locations between fertile and infertile women throughout different menstrual phases. The relationship between progesterone level and LIF expression were evaluated.

METHODS

Endometrial biopsies were performed on idiopathic infertile and normal fertile women accepted the in follicular, periovulatory, and luteal phases. The luteal progesterone level was measured. Endometrial LIF immunostaining of luminal epithelium, glandular epithelium, and stroma were detected. The relationship between luteal LIF expression and progesterone level was evaluated.

RESULTS

Significant LIF expression was noted in the endometrium of fertile women rather than that of infertile women. The LIF expression was highest in the luminal epithelium, moderate in the glandular epithelium, and lowest in the stroma. The luminal and glandular epithelial staining were lowest in follicular phase, moderate in periovulatory phase, and strongest in luteal phase. The stromal LIF presented with a noncyclical manner. The LIF expression is not related with the progesterone level.

CONCLUSIONS

Endometrial LIF expression is related to human fertility. Endometrial LIF expression is dependent on cellular localizations and menstrual stages. Stronger LIF expression presents in the endometrial epithelium during luteal phase.

Restoration of gap junctional intercellular communication by caffeic acid phenethyl ester (CAPE) in a ras-transformed rat liver epithelial cell line

Caffeic acid phenethyl ester (CAPE), an active ingredient of honeybee propolis, has been identified as having anti-inflammatory, anti-viral and anti-cancer properties. Since the deficiency of gap junctional intercellular communication (GJIC) has been shown to be a characteristic of most cancer cells, this study was designed to test the hypothesis that the anti-carcinogenic activity of CAPE might be related to its ability to restore GJIC in tumorigenic GJIC-deficient cells (WB-ras2 cells). The results showed that CAPE restored GJIC, phosphorylation of connexin 43 (Cx43) and its normal localization on the plasma membrane in WB-ras2 cells after 3 days at 5 microg/ml concentration. Additionally, CAPE inhibited growth in soft agar and decreased the protein level of p21(ras). The results are consistent with the hypothesis that the anti-cancer mechanism of CAPE may be mediated by its ability to restore GJIC.

Successful application of extracorporeal membrane oxygenation and intra-aortic balloon counterpulsation as lifesaving therapy for a patient with amniotic fluid embolism

A woman in labor was noted to have amniotic fluid embolism. Extracorporeal membrane oxygenation and intra-aortic balloon counterpulsation were performed post partum, and the vital signs became stable. The ensuing recovery was uneventful. We conclude that extracorporeal membrane oxygenation and intra-aortic balloon counterpulsation should be considered to save the life of a patient with amniotic fluid embolism and left ventricular failure unresponsive to medical therapy.

Decreased CD10-positive mature granulocytes in bone marrow from patients with myelodysplastic syndrome

OBJECTIVE

We retrospectively examined the maturation of the granulocytic cell lineage in bone marrow specimens from patients with myelodysplastic syndrome (MDS) by flow cytometry using both light scatter and surface marker characteristics, including CD10 and myeloid lineage-associated antigens.

PATIENTS

The 7 MDS cases we studied included 2 patients with refractory anemia (RA), 3 with RA with ringed sideroblasts, 1 with RA with excess of blasts, and 1 unclassified case. Another 7 patients matched for age and sex who received bone marrow aspirates for lymphoma staging (all negative for lymphoma involvement or any other hematologic abnormalities) were selected as the control group.

RESULTS

The percentage of CD10(+) mature granulocytes was significantly lower in patients with MDS than in control patients. Additionally, all patients with MDS had less than 50% CD10(+) cells in the granulocytic lineage. In contrast, only 1 of the 7 control patients had less than 50% CD10(+) cells (P <.01).

CONCLUSIONS

These results suggest that flow cytometry might be a useful adjunct in the assessment of patients with suspected MDS. Further studies to correlate CD10(+) mature granulocytes from MDS cases with other benign hematologic disorders are indicated to confirm our evaluation.

Lambda-carrageenan-induced inhibition of gap-junctional intercellular communication in rat liver epithelial cells

lambda-Carrageenan, a food additive extracted from red seaweed, is widely used as an emulsifier, stabilizer, or thickener. Previously, it has been shown that carrageenan could play a role in carcinogenesis. However, the mechanism by which it might influence the multimechanism, multistep process of carcinogenesis is not known. Gap-junctional intercellular communication (GJIC) has been associated with maintaining homeostatic regulation of cell proliferation and differentiation. Most cancer cells have dysfunctional GJIC, and many tumor-promoting chemicals, growth factors, and oncogenes can downregulate GJIC. The experiments in this study were designed to test the hypothesis that carrageenan might function as a tumor-promoting chemical by inhibiting GJIC. To test this hypothesis, nontumorigenic rat liver epithelial cells were exposed to carrageenan, and GJIC was measured. Western blot analysis and immunofluorescent staining were used to monitor the phosphorylation and localization of connexin 43. The data revealed inhibition of GJIC by carrageenan similar to that by the well-documented tumor promoter phorbol ester. However, the phosphorylation and localization of connexin 43 were not altered. Although the mechanism by which carrageenan inhibits GJIC is unknown, carrageenan's influence on the carcinogenic process might be via its ability to be a tumor promoter.

Double phase conjugation with orthogonally polarized beams in a BaTiO(3) crystal

We have demonstrated experimentally the simultaneous self-conjugation of extraordinarily and ordinarily polarized light waves (lambda=514 nm), with the polarization state preserved, in a Ce:BaTiO(3) crystal. Conjugate o waves originate from coupling between o and e waves by means of a circular photogalvanic effect. The conjugator also takes advantage of the Ce:BaTiO(3) crystal, for which it is easy to generate an extraordinary conjugate beam by photorefractive backscattering. This beam of light is necessary for double phase conjugation.

Serologic and molecular evidence of Ehrlichia spp. in coyotes in California

In order to determine the role of coyotes in the epidemiology of granulocytic and monocytic ehrlichial agents in California (USA), we tested 149 serum samples for antibodies against Ehrlichia equi, E. risticii, and E. canis, using an indirect immunofluorescent antibody test. Polymerase chain reaction (PCR) assay was used to survey for the presence of members of the E. phagocytophila genogroup, E. risticii and E. canis in blood samples of 95 coyotes. Sixty-eight (46%) samples were seropositive for E. equi, two (1%) for E. risticii and none of the samples had antibodies reactive to E. canis. Two and one coyote were positive for E. risticii and members of the E. phagocytophila genogroup by PCR assay, respectively. In contrast, the 95 samples were negative for E. canis by PCR. Ninety-five percent of the 68 E. equi seropositive coyotes and the one coyote PCR positive for members of the E. phagocytophila genogroup originated from a coastal area. However, the two E. risticii seropositive coyotes and the two coyotes PCR positive for E. risticii were from northern California. Sequence analysis of the three amplified PCR products revealed the agent to be similar in two coyotes to the sequences of E. risticii from horses originating from northern California and identical in one coyote to the agent of human granulocytic ehrlichiosis and E. equi from California. Thus, coyotes are exposed to granulocytic ehrlichiae and E. risticii and may play a role in the epidemiology of these ehrlichial agents in California.

Effect of different concentrations of recombinant leukemia inhibitory factor on different development stage of mouse embryo in vitro

PURPOSE

To assess the influence of different concentrations of recombinant human leukemia inhibitory factor (LIF) on the in vitro development of mouse embryos.

METHODS

The 2- to 4-cell embryos of CB6F1 mice were cultured in the human tubal fluid (HTF) media containing different concentrations of LIF. Mouse embryos were divided into seven groups: (1) HTF; (2) 1500 IU/ml LIF; (3) 1000 IU/ml LIF; (4) 750 IU/ml LIF; (5) 500 IU/ml LIF; (6) 250 IU/ml LIF; (7) 125 IU/ml LIF. The embryonic numbers of different stages including 5-8 cell, 9-16 cell, morula, blastocyst, and hatching blastocyst were recorded.

RESULTS

The percentage of early embryo stage (2-cell embryos to 6- to 16-cell stages) in all groups were nonsignificantly different. There were higher formation rates of preimplantation embryos (morula to hatching blastocyst) in groups 2, 3, 4, and 5 than in groups 1, 6 and 7.

CONCLUSIONS

LIF has positive effects on preimplantation embryo development and has nonsignificant influence on the early embryo development. The lowest concentration of LIF which could provide the optimal embryo development is 500 IU/ml.

Quantitative analysis of the regulation of leukocyte chemosensory migration by a vascular prosthetic biomaterial

The need for improved, infection-resistant vascular biomaterials calls for more objective evaluation of the immune pathophysiology of implantable prosthetic materials. In this study we have developed a new strategy to quantitatively characterize population-averaged responses of immune cell migration on vascular prosthetic materials. This approach, incorporating a chemokinetically regulated "biomaterial-gel" sandwich configuration, was applied to quantify both random and directed modes of the chemosensory migration of human neutrophil leukocytes on expanded polytetrafluoroethylene (ePTFE). Our studies show that (a) microporous, synthetic materials like ePTFE suppress the basal rate of random cell migration relative to that reported on non-porous control surfaces; (b) stimulation with chemoattractant (formyl peptide) can significantly elevate rates of random and directed migration on ePTFE; and (c) protein conditioning of ePTFE with albumin or immunoglobulin G can differentially modulate the rates and relative proportion of random and directional components of leukocyte migration response to chemoattractant. This, to our knowledge, is the first objective quantitation of chemokinetically regulated cell migration on implantable prosthetic materials.

Adaptive optics: wave-front correction by use of adaptive filtering and control

A class of adaptive-optics problems is described in which phase distortions caused by atmospheric turbulence are corrected by adaptive wave-front reconstruction with a deformable mirror, i.e., the control loop that drives the mirror adapts in real time to time-varying atmospheric conditions, as opposed to the linear time-invariant control loops used in conventional adaptive optics. The basic problem is posed as an adaptive disturbance-rejection problem with many channels. The solution given is an adaptive feedforward control loop built around a multichannel adaptive lattice filter. Simulation results are presented for a 1-m telescope with both one-layer and two-layer atmospheric turbulence profiles. These results demonstrate the significant improvement in imaging resolution produced by the adaptive control loop compared with a classical linear time-invariant control loop.

Sperm cryopreservation with empty human or mouse zona pellucidae. A comparison

OBJECTIVE

To compare empty zona pellucidae (ZP) and human of mouse oocytes for sperm cryopreservation.

STUDY DESIGN

ZP was prepared by evacuating the cytoplasm of human or mouse oocytes. The evacuated ZP were injected with spermatozoa from patients with severe oligoasthenozoospermia from normally fertile men. After a freezing-thawing procedure, the spermatozoa were aspirated outside the ZP. According to the different origins of ZP and sperm, the spermatozoa number per ZP, motile sperm number before freezing and after thawing, lost sperm number per ZP after freezing and sperm recovery rate were compared.

RESULTS

Spermatozoa number, motile sperm number before freezing and after thawing, lost sperm number per ZP and sperm recovery rate in all groups were comparable. The total mean motile sperm number before freezing and after thawing, mean lost sperm number after thawing and sperm recovery rate were 15.1%, 12%, 1.6% and 80%, respectively.

CONCLUSION

ZP is an ideal vehicle for cryopreservation of sperm collected from patients with severe oligoasthenozoospermia. There were no differences between human and mouse ZP for sperm storage.

A case-control study of successful maintenance of a substantial weight loss: individuals who lost weight through surgery versus those who lost weight through non-surgical means

OBJECTIVE

To determine if method of weight loss (surgery; non-surgery) is associated with current levels of psychosocial functioning or current weight maintenance behaviors in individuals who have lost large amounts of weight.

DESIGN

Subjects were 67 cases and 67 controls selected from the National Weight Control Registry, a longitudinal study of individuals successful at long-term maintenance of weight loss. Cases had initially lost weight through bariatric surgery while controls had lost weight through non-surgical means. The current psychosocial functioning and weight maintenance behaviors of cases and controls were assessed and compared.

RESULTS

Cases and controls were matched on gender, current weight and total weight loss. Surgical cases reported significantly higher fat intake and lower physical activity levels. There were no differences in cases' and controls' reports of the impact of weight loss on other areas of their lives, neither were there differences on measures of depression or binge-eating.

CONCLUSIONS

Reported improvement in psychosocial functioning did not depend upon how weight was initially lost, but cases and controls appear to be using very different behaviors to maintain their weight losses.

Identification and genetic characterization of Haemophilus influenzae genetic island 1

The type b capsule of pathogenic Haemophilus influenzae is a critical factor for H. influenzae survival in the blood and the establishment of invasive infections. Other pathogenic factors associated with type b strains may also play a role in invasion and sustained bacteremia, leading to the seeding of deep tissues. The gene encoding haemocin is the only noncapsular gene found to be specific to type b strains until now. Here we report the discovery of an approximately 16-kb genetic locus, HiGI1, that is present primarily in type b strains. Pulsed-field gel electrophoresis and Southern hybridization were used to map this new locus between secG (HI0445) and fruA (HI0446), which are contiguous in Rd, a nonpathogenic derivative of a serotype d strain. It is inserted at the 3' end of tRNA(4)(Leu) and has regions whose G+C content differs from the average genomic G+C content of H. influenzae. An integrase gene, which encodes a CP4-57 like integrase, is located downstream of tRNA(4)(Leu). Hybridization probes based on the sequences within the HiGI1 locus have been used to screen 61 H. influenzae strains (2 type a, 22 type b, 2 type c, 1 type d, 3 type e, 7 type f, and 21 nontypeable H. influenzae [NTHi]) from our collection. This HiGI1 locus exists in all 22 type b strains and two NTHi strains and is likely to have been acquired by an ancestral type b strain.

Deep neck infections in diabetic patients

PURPOSE

Deep neck infections may be lethal if life-threatening complications occur, especially in immunocompromised hosts such as diabetic patients. This study was undertaken to better define the clinical features and prognosis of deep neck infections in the diabetic patients with special emphasis on the use of empirical antibiotics and the role and timing of surgical management.

PATIENTS AND METHODS

A retrospective analysis of 105 consecutive patients treated at a single institution during a 9-year period was conducted. Of these, 30 patients also presented with diabetes mellitus.

RESULTS

Compared with the nondiabetic patients, the unique features of deep neck infections in diabetic patients were as follows: (1) older age, (2) tendency of unclear infection source, (3) tendency to involve multiple spaces, (4) required more aggressive surgical intervention, (5) prolonged hospitalization, and (6) higher complication rate. The differences were statistically significant (P< .05). There were no significant differences in the complete blood count/ differential count positive findings and fever between the 2 groups (P> .05). Bacterial cultures showed that Klebsilla pneumoniae was the most common causative pathogen in diabetic patients.

CONCLUSIONS

In deep neck infection patients with diabetes mellitus, the clinical course is more severe and there is a poorer prognosis. Thus, in treating them, we should keep close observation, appropriately control the diabetes, detect the life-threatening complications early, perform aggressive surgical treatment if fluctuation or complication occurs, and take into account the preponderance of K pneumoniae when administering the empirical antibiotics.

Long-term trends in exposures to nickel aerosols

A comprehensive evaluation of temporal changes in exposure to nickel aerosols in the nickel-producing and nickel-using industries was conducted. For various nickel compounds, trends in the geometric mean exposure levels were evaluated on the basis of job group, building, plant, and industrial sector. At each level of classification, approximately two-thirds of the data provided evidence of workplace declines in exposures. Depending on how exposure measurements were aggregated, approximately one-quarter to one-half of the data produced statistically significant trends, with far more exposures declining than increasing over time. Whereas significantly negative linear trends were detected for total nickel exposures in the mining (-7%/yr), smelting (-9%/yr), and refining (-7%/yr) sectors, total nickel exposures in milling showed a significantly positive trend (+4%/yr). When the data were classified at the job group, building, or plant level, the median rate of change in exposure levels was -4, -6, and -3%/yr, respectively. For a subset of the data, effects of various factors related to work environment, process, and nature of the job on trends in exposure levels were evaluated. When such factors were examined simultaneously, the results suggested that the decline in exposures was greater in workplaces with no ventilation system compared with ventilated workplaces, in groups of workers who performed similar rather than diverse tasks, and in North American workplaces compared with workplaces in Europe and Western Australia. These results could be used in the design of prospective sampling protocols and in future retrospective health-effects studies of workers in the nickel industries.

Purification and characterization of neutral sphingomyelinase from Helicobacter pylori

Phospholipase activities of human gastric bacterium, Helicobacter pylori, are regarded as the pathogenic factors owing to their actions on epithelial cell membranes. In this study, we purified and characterized neutral sphingomyelinase (N-SMase) from the superficial components of H. pylori strains for the first time. N-SMase was purified 2083-fold with an overall recovery of 37%. The purification steps included acid glycine extraction, ammonium sulfate precipitation, CM-Sepharose, Mono-Q, and Sephadex G-75 column chromatography. Approximate molecular mass for the native N-SMase was around 32 kDa. When N-omega-trinitrophenylaminolauryl sphingomyelin (TNPAL-SM) was used as a substrate, the purified enzyme exhibited a K(m) of 6.7 microM and a V(max) of 15.6 nmol of TNPAL-sphingosine/h/mg of protein at 37 degrees C in 50 mM phosphate-buffered saline, pH 7.4. N-SMase reaches optimal activity at pH 7.4 and has a pI of 7.15. The enzyme activity is magnesium dependent and specifically hydrolyzed sphingomyelin and phosphatidylethanolamine. The enzyme also exhibits hemolytic activity on human erythrocytes. According to Western blot analysis, a rabbit antiserum against purified N-SMase from H. pylori cross-reacted with SMase from Bacillus cereus. Sera from individuals with H. pylori infection but not uninfected ones recognizing the purified N-SMase indicated that it was produced in vivo. In enzyme-linked immunosorbent assays, the purified N-SMase used as an antigen was as effective as crude protein antigens in detecting human antibodies to H. pylori.

Regulation of plastid rDNA transcription by interaction of CDF2 with two different RNA polymerases

The plastid genome is known to be transcribed by a plastid-encoded prokaryotic-type RNA polymerase (PEP) and by a nucleus-encoded phage-type RNA polymerase (NEP). The spinach plastid rrn operon promoter region harbours three different, overlapping promoters. Two of them are of the prokaryotic type. The third promoter is a non-consensus-type NEP promoter. We separated three different transcriptional activities from spinach chloroplasts: PEP, the phage-type RNA polymerase NEP-1, and a third, hitherto undescribed transcriptional activity (NEP-2). NEP-2 specifically transcribes the rrn operon in the presence of the transcription factor CDF2. CDF2 was previously shown to recruit PEP to the rrn promoter to repress transcription. Together, our results suggest the existence of a third RNA polymerase in plastids and a mechanism of rDNA transcriptional regulation that is based on the interaction of the transcription factor CDF2 with two different transcriptional systems.

Expression of c-Myc and p53 correlates with clinical outcome in diffuse large B-cell lymphomas

We performed a retrospective immunohistochemical study of the relationships between clinical manifestations and outcomes of diffuse large B-cell lymphoma (DLBCL) and expression of oncogenic proteins in 21 cases of DLBCL at various clinical stages. Cases of nodal origin expressed p53 more often and presented with high clinical stage more frequently than those of extranodal origin. Expression of c-Myc or p53, but not Bcl-6, Bcl-2, or Bcl-1, showed a statistically significant positive correlation with high clinical stage at presentation and with high or high-intermediate risk. Coexpression of c-Myc and p53 occurred in 7 of 12 patients with high clinical stage but was absent in patients with low clinical stage; coexpression was more frequent in patients with high or high-intermediate risk than in patients with low or low-intermediate risk. Four patients with this coexpression pattern demonstrated an unusually aggressive clinical course (median survival, 7 months). Coexpression of c-Myc and p53 seems to be a better indicator than the MIB1 proliferative index for identification of a cohort of aggressive disease in patients with DLBCL.

Expression and high-level secretion of Trichoderma reesei endoglucanase I in Yarrowia lipolytica

The endoglucanase I (EGI) from fungus Trichoderma reesei was cloned, expressed, and secreted from Yarrowia lipolytica using the XPR2 promoter. The signal sequence of EGI transferred from T. reesei was efficiently processed in the Y. lipolytica secretory pathway and directed the secretion of active EGI into the culture medium. However, the recombinant EGI produced from YLCSIn strain was hyperglycosylated and significantly larger than the native enzyme produced by the parent strain. The expression of EGI using XPR2 preproregion has caused secretion of modified proteins that still retained cellulase activity. This resulted from imprecise processing of the N-terminus of recombinant protein. While the batch culture produced 5 mg EGI/L from YLCSIn strain, the EGI yield was increased approx 20-fold when the fed-batch fermentation process strategy in combination with the high-cell density cultivation technique was employed. These results showed that the Y. lipolytica is a useful host organism for production of a large amount of large size heterologous proteins, especially when used in combination with high-cell density and fed-batch culture techniques.

Prolonged culture of human cryopreserved embryos with recombinant human leukemia inhibitory factor

PURPOSE

To evaluate the efficiency of recombinant human leukemia inhibitory factor (LIF) in the prolonged culture of human cryopreserved-thawing embryos.

METHODS

After thawing, all embryos were divided into four groups: (1) Human tubal fluid (HTF), (2) HTF + LIF, (3) M3TH medium, and (4) M3TH medium plus LIF. Following prolonged culture, embryo development in each group was compared.

RESULTS

In embryo development from about the 2- to 4-cell to 9- to 16-cell stage, there were nonsignificant differences between each group. There was lower morula formation rate in group 1 (6.9%) than those in other groups (23.2%, 19.7%, 23.1%). The lower blastocyst formation in group 1 and 3 (0%, 0%) than those in group 2 and 4 (11.0%, 12.8%) were noted.

CONCLUSIONS

LIF is beneficial for preimplantation embryos. LIF does not influence the early embryo development. LIF-supplemented HTF provided a similar culture environment for thawing embryos as LIF-supplemented M3TH medium.

Artificial insemination. Role of endometrial thickness and pattern, of vascular impedance of the spiral and uterine arteries, and of the dominant follicle

OBJECTIVE

To assess the roles of endometrial thickness and pattern, as well as vascular impedance of the spiral and uterine arteries and dominant follicle in predicting the pregnancy rate in women receiving controlled ovarian hyperstimulation (COH) following by intrauterine insemination (IUI).

STUDY DESIGN

All idiopathically infertile couples who accepted COH + IUI for the first time were prospectively included. The COH agents included clomiphene citrate and human menopausal gonadotropins. Endometrial thickness and pattern (trilaminar, nontrilaminar) and vascular impedance (pulsatility index [PI], resistance index [RI]) of the spiral and uterine arteries and ovarian dominant follicle were measured on the day of IUI. Analyses were made of the influences on pregnancy outcomes by endometrial thickness and pattern as well as Doppler surveys of the spiral and uterine arteries and dominant follicle.

RESULTS

A total of 110 couples with 110 cycles were enrolled, and there were 16 resulting pregnancy cycles. Trilaminar endometrium appeared in 87.5% and 57.4% of pregnant and nonpregnant women (P = .022), respectively. The pregnancy rates in trilaminar and nontrilaminar groups were 17.9% and 6.3%, respectively (P = .022). Endometrial thickness and PI/RI values for the spiral artery and uterine arteries and dominant follicle in pregnant women (12.1 +/- 2.6; 1.28 +/- 0.33/0.68 +/- 0.12; 2.67 +/- 0.51/0.72 +/- 0.32; 0.71 +/- 0.19/0.54 +/- 0.06 mm, respectively) were not statistically different from those for nonpregnant women (11.0 +/- 2.9; 1.46 +/- 0.49/0.71 +/- 0.21; 2.81 +/- 0.65/0.88 +/- 0.34; 0.74 +/- 0.24/0.55 +/- 0.09, respectively).

CONCLUSION

A trilaminar endometrium on the day of IUI provides a favorable prediction of pregnancy. Endometrial thickness and Doppler surveys of the spiral and uterine arteries and dominant follicle do not have useful predictive value in COH + IUI.

Low-dose aspirin for infertile women with thin endometrium receiving intrauterine insemination: a prospective, randomized study

PURPOSE

The objective was to evaluate the effect of aspirin on infertile women with thin endometrium.

METHODS

Patients who had thin endometrium (< or = 8 mm) and intrauterine insemination were divided into the aspirin and nonaspirin groups. Endometrial pattern (trilaminar and nontrilaminar) and thickness, the pulsatility index (PI) and resistance index (RI) of the uterine artery, spiral artery, and ovarian dominant follicles, and pregnancy rates of both groups were measured.

RESULTS

A total of 114 and 122 women were included in the aspirin and nonaspirin groups, respectively. There were significantly higher percentages of trilaminar endometrium (46.5% vs. 26.2%) and pregnancy rate (18.4% vs. 9.0%) after aspirin therapy. There was nonsignificant difference in the endometrial thickness, and PI/RI values of the uterine artery, spiral artery, and ovarian dominant follicle between both groups.

CONCLUSIONS

Higher pregnancy rate and better endometrial pattern were achieved in patients with thin endometrium after aspirin administration. Aspirin therapy could not significantly increase the endometrial thickness and the resistance of uterine and ovarian flow.