Public health clinic-based hepatitis C testing and linkage to care in Baltimore.

Testing and linkage to care are important determinants of hepatitis C virus (HCV) treatment effectiveness. Public health clinics serve populations at high risk of HCV. We investigated their potential to serve as sites for HCV testing, initiation of and linkage to HCV care. Cross-sectional study of patients accessing sexually transmitted infection (STI) care at the Baltimore City Health Department (BCHD) STI clinics, from June 2013 through April 2014 was conducted. Logistic regression was used to assess factors associated with HCV infection and specialist linkage to care. Between 24 June 2013 and 15 April 2014, 2681 patients were screened for HCV infection. Overall, 189 (7%) were anti-HCV positive, of whom 185 (98%) received follow-up HCV RNA testing, with 155 (84%) testing RNA positive. Of 155 RNA-positive individuals, 138 (89%) returned to the STI clinic for HCV RNA results and initial HCV care including counselling regarding transmission and harm reduction in alcohol, and 132 (85%) were referred to a specialist for HCV care. With provision of patient navigation services, 81 (52%) attended an offsite HCV specialist appointment. Alcohol use and lack of insurance coverage were associated with lower rates of specialist linkage (OR 0.4 [95% CI 0.1-0.9] and OR 0.4 [95% CI 0.1-0.9], respectively). We identified a high prevalence of HCV infection in BCHD STI clinics. With availability of patient navigation services, a large proportion of HCV-infected patients linked to off-site specialist care.

Primary Care Providers Knowledge, Attitude and Practices Related to Hepatitis C Screening and Treatment in the Oral Direct Acting Antiviral Agents Era.

BACKGROUND: There are over 3 million Americans infected with hepatitis C virus (HCV). Despite recent advances in HCV treatment, a major barrier to care remains a limited number of treaters. HCV therapy provision by primary care providers (PCPs) could expand access by increasing the pool of HCV treating clinicians. OBJECTIVE: To characterize current HCV care practices, willingness and self-efficacy of PCPs to become HCV treaters. DESIGN PARTICIPANTS AND MAIN MEASURES: Two hundred and seventy one PCPs were identified from community clinics affiliated with a large academic center and 4 large federally qualified health centers in Baltimore, MD. An internet-based survey was administered to assess provider demographics, clinical practice site and willingness to provide HCV care. Factors associated with willingness to provide HCV care were examined using odds ratios (OR). KEY RESULTS: Among 129 (48%) PCPs who responded, the majority (70%) had an MD/DO degree and were white (60%). Only a few PCPs, 12 (10%), had treated at least 1 patient for HCV in the prior year. Although only 22% agreed that HCV treatment should be provided by PCPs, 84% were interested in more HCV training. Willingness to provide treatment was strongly linked to having a high proportion of HCV-infected patients (>20% versus <20%; OR 3.9; 95% confidence interval [CI] 1.5-10) and availability of other services at the primary care site including HIV treatment (OR 6.5; 95% CI 2.5-16.5), substance abuse treatment (OR 3.3; 95% CI 1.3-8.4) and mental health services (OR 4.9; 95% CI 2.0-12.1). CONCLUSION: These data suggest that efforts to expand HCV medical provider capacity will be most impactful if they initially focus HCV training on PCPs with a high prevalence of HCV among their patients and existing systems to support HCV care.

Altered muscle development and expression of the insulin-like growth factor system in growth retarded fetal pigs.

We have used a porcine model of spontaneous differential fetal growth to investigate the effects of fetal size on muscle development. We hypothesized that altered muscle development may occur in small fetuses as a consequence of modified expression of selected genes of the insulin-like growth factor system. We examined the development of the Longissimus muscle (m. Longissimus) in small fetuses and their average sized littermates. We collected small for gestational age fetuses and their average sized sibling on days 45, 65 and 100 of gestation (term is 113-116 days). Small fetuses had significantly lower body weight at all three stages of gestation (p<0.05) and significantly reduced secondary to primary muscle fibre ratio in m. Longissimus on day 100 (p<0.05) compared to their littermates. On day 65, the expression of insulin-like growth factor receptor 1 and insulin-like growth factor binding protein 3 were significantly higher (p<0.05) in m. Longissimus of the small fetuses compared with their average sized littermates. On day 100, the expression of insulin-like growth factor receptor 1 remained significantly higher (p=0.001), in addition to significantly higher levels of insulin-like growth factor receptor 2 and insulin-like growth factor binding protein 5 in the small fetuses (p<0.05). No difference in levels of myogenin was observed between the small and average sized littermates. In conclusion, we demonstrate that reduced fetal muscle development is associated with an increased expression of several genes of the insulin-like growth factor system in small fetuses in mid to late gestation.

Expression and adaptive regulation of amino acid transport system A in a placental cell line under amino acid restriction.

Trans-placental transport of amino acids is vital for the developing fetus. Using the BeWo cell line as a placental model, we investigated the effect of restricting amino acid availability on amino acid transport system type A. BeWo cells were cultured either in amino acid-depleted (without non-essential amino acids) or control media for 1, 3, 5 or 6 h. System A function was analysed using alpha(methyl-amino)isobutyric acid (MeAIB) transcellular transport studies. Transporter (sodium coupled neutral amino acid transporter (SNAT1/2)) expression was analysed at mRNA and protein level by Northern and Western blotting respectively. Localisation was carried out using immunocytochemistry. MeAIB transcellular transport was significantly (P < 0.05) increased by incubation of the cells in amino acid-depleted medium for 1 h, and longer incubation times caused further increases in the rate of transfer. However, the initial response was not accompanied by an increase in SNAT2 mRNA; this occurred only after 3 h and further increased for the rest of the 6-h incubation. Similarly, it took several hours for a significant increase in SNAT2 protein expression. In contrast, relocalisation of existing SNAT2 transporters occurred within 30 min of amino acid restriction and continued throughout the 6-h incubation. When the cells were incubated in medium with even lower amino acid levels (without non-essential plus 0.5 x essential amino acids), SNAT2 mRNA levels showed further significant (P < 0.0001) up-regulation. However, incubation of cells in depleted medium for 6 h caused a significant (P = 0.014) decrease in the expression of SNAT1 mRNA. System L type amino acid transporter 2 (LAT2) expression was not changed by amino acid restriction, indicating that the responses seen in the system A transporters were not a general cell response. These data have shown that placental cells adapt in vitro to nutritional stress and have identified the physiological, biochemical and genomic mechanisms involved.

Sodium transport across the chorioallantoic membrane of porcine placenta involves the epithelial sodium channel (ENaC).

The properties of chorioallantoic membrane derived from Large White Landrace sows at 45, 65 and 100 days gestation are examined. Under short circuit conditions positive charge flows from fetal to maternal sides of the tissue. Na+ is shown to be the sole charge carrier as the short circuit current is inhibited reversibly by fetal applications of amiloride and replacement of Na+ by choline in the Ringer solution, and irreversibly by both fetal and maternal applications of ouabain. The initial short circuit current is smaller at day 100 compared to days 45 and 65. The dose responses to amiloride indicate that the epithelial sodium channel (ENaC) is involved in the movement of Na+ and that it is accessible on the fetal side of the tissue only. Immunostaining shows that the ENaC-alpha subunit is present in both the allantoic membrane and the trophoblast. Uptake studies using microvillous (apical) membrane vesicles suggest it is either inactive or only weakly active at this site. The trophoblast at day 100 has a higher content of ENaC than at days 45 and 65. This is the first report of the presence of ENaC in placental tissues. The effects of ouabain indicate the presence of a Na+ pump that is more readily inhibited by applications of the drug on the maternal aspect of the tissue than on the fetal side. Differential mechanisms may be present that would allow net movement of Na+ in either direction across the chorioallantoic membrane according to the changing demands of the developing fetus.

Waterhouse-Friderichsen syndrome after infection with group A streptococcus.

We report a case of Waterhouse-Friderichsen syndrome associated with group A streptococcus (GAS) toxic shock syndrome in a previously healthy man. The patient presented with neck pain and fevers of 2 days' duration. Computed tomography of the neck revealed a mass in the retropharyngeal space, suggesting an abscess. Despite prompt treatment with appropriate antibiotics, the patient experienced a fulminant course and died within 8 hours of presentation. Antemortem blood cultures grew GAS positive for exotoxins A, B, and C. Postmortem examination revealed bilateral adrenal hemorrhage, consistent with Waterhouse-Friderichsen syndrome. Immunohistochemical analysis of the adrenal glands revealed the presence of GAS antigens. However, no disseminated intravascular coagulation was evident. This case demonstrates that adrenal hemorrhage can occur without associated coagulopathy and may result directly from the action of bacterial toxins.

Causes and consequences of fetal growth retardation in pigs.

In pigs, as in other species, fetal growth retardation is associated with reduced birth weight and increased risk of fetal and neonatal death. As there are few opportunities after birth to remedy the detrimental effects of low birth weight, it is important to understand both the intrinsic and extrinsic factors associated with inadequate fetal growth and to determine when growth retarded fetuses deviate from the growth trajectory of their normal sized littermates. Inadequately grown pig fetuses can be identified statistically as early as day 30 of the 114 days of gestation, indicating that limited uterine space is not a primary determinant of fetal growth. Comparisons of the smallest fetus within a litter with a normal sized sibling reveal that inadequately grown fetuses have altered endocrine status and lower circulating concentrations of many essential amino acids. In addition, the placenta supplying the smallest fetus is disproportionately small and has a reduced capacity to transport amino acids. Understanding the timing and the causes of fetal growth retardation in pigs may help us to devise appropriate strategies to reduce the incidence and hence the detrimental postnatal consequences of runting.

Maternal cigarette smoking and oxygen diffusion across the placenta.

The aim of this study was to test whether or not adaptations in partial, total and specific oxygen diffusive conductances occur in the placentae of women who smoke cigarettes during pregnancy and help to compensate for intrauterine fetal hypoxic stress. Tissue sections were randomly sampled from human term placentae divided into two groups (non-smokers and smokers) according to maternal smoking status. In smokers, status was expressed as either declared smoking rate or level of plasma cotinine (the major metabolite of nicotine). Sections were analysed stereologically to estimate key structural quantities (vascular volumes, exchange surface areas, tissue diffusion distances). These were combined with previously-published physicochemical quantities (oxygen-haemoglobin reaction rates and tissue oxygen diffusion coefficients) in order to estimate the partial conductances of six tissue compartments of the oxygen pathway: maternal erythrocytes and plasma, villous trophoblast, villous stroma (including fetal capillary wall), fetal plasma and erythrocytes. From partial conductances and birthweights, total and specific conductances were calculated for each placenta. Results were assessed statistically by analyses of variance and t -tests. Despite apparent improvements in the partial conductances of the maternal erythrocytes and plasma, total and specific conductances did not alter significantly in smoking groups. However, the relative biases affecting these estimates may be different in smokers and non-smokers. We conclude that total conductance does not increase in placentae associated with maternal smoking. However, given that the fetus suffers chronic hypoxic stress as a consequence of smoking (evidenced here by elevated haematocrits), even a constant diffusive conductance implies a reduced transplacental partial pressure gradient. This could be a contributory factor to the reduced birthweight.

Identification and characterization of SKAT-2, a novel Th2-specific zinc finger gene.

We have identified a novel Kruppel-type zinc finger (ZF) gene, SKAT-2, which is selectively expressed by murine Th2 cells. The protein encoded by this gene has 14 C2H2-type ZF tandemly arrayed at its C terminus and N-terminal SCAN box and KRAB domains. SKAT-2 is tissue restricted in expression at the RNA level, detectable only in brain and at low levels in kidney and spleen and few hematopoietic cell lines. By in situ hybridization, SKAT-2 expression was found to peak in antigen-stimulated CD4(+) T cells after 2-3 days of culture under Th2 but not Th1 biasing conditions. This pattern of expression closely mirrored that of GATA-3 in the same cells. In transient transfection experiments in phorbol 12-myristate 13-acetate/ionomycin-stimulated EL4 cells, SKAT-2 was found to up-regulate the activity of the IL-4 but not the IL-5 promoter, contrasting with the ability of GATA-3 to activate both promoters. This result was confirmed using clones of EL4 cells stably expressing an inducible form of SKAT-2, thus SKAT-2 is a novel Th2-specific gene that may play a role in selective regulation of cytokine genes in T cells.

A quantitative study on the effects of maternal smoking on placental morphology and cadmium concentration.

The aim of this study was to quantify the effects of maternal cigarette smoking on placental morphology, paying particular attention to variables known to be influential in facilitating oxygen diffusion. Structural quantities were estimated by stereological analyses of placental samples drawn from non-smoking and smoking women whose smoking habits were assessed both subjectively (from volunteered cigarette consumption) and objectively (by determining levels of plasma cotinine, a major metabolite of nicotine). Concentrations of placental cadmium were also measured. In the smoking group, maternal and fetal haematocrits were elevated and mean birthweight was reduced. Within placentae, the most significant alterations were increases in cadmium levels, the relative volumes of maternal intervillous space, the relative surface areas of fetal capillaries and decreases in the relative and absolute volumes of fetal capillaries. Findings indicate that changes in capillary volume are the result of a decrease in mean capillary diameter rather than total length. The mean thickness of the trophoblast component of the villous membrane was also increased in the smoking group. Although increased haematocrits suggest that fetuses of smoking mothers suffer hypoxic stress, these morphological changes are likely to compromise, rather than assist, transplacental oxygen transfer. This is in marked contrast to the adaptive changes seen in pregnancies associated with preplacental hypoxia and suggests that other factors might be compromising the fetoplacental unit. Finally, although the morphological changes associated with maternal smoking seem to be the result of an all-or-none, rather than dose-dependent, effect, the available evidence is not conclusive.

Variable inhibition of placental IgG transfer in vitro with commercial IVgG preparations.

Maternal administration of high-dose intravenous immunoglobulin (IVIgG) for treating fetal RhD haemolytic disease and alloimmune thrombocytopenias may be beneficial. Treatment failures, even when IVIgG is used optimally, may result from product differences. Using an in vitro placental perfusion model there was significant inhibition of placental anti-D IgG transfer with three commercial IVIgG preparations where circulating maternal IgG concentrations were > 20 g/l. One IVIgG product, which was not inhibitory, had lower circulating IgG levels (16.5 +/- 0.9 g/l) and significantly reduced placental transfer of total IgG, suggesting that the reduced functional activity of IgG from IVIgG preparations may correlate with poor clinical efficacy.

Transfer of anti-D antibodies across the isolated perfused human placental lobule and inhibition by high-dose intravenous immunoglobulin: a possible mechanism of action.

Using an in vitro perfusion model, therapeutic intravenous immunoglobulin (IVIgG) and IgG anti-D have been shown to cross the placenta from the maternal circuit to the fetal circuit. The transfer of all IgG species was linear with respect to time, and the amount of IgG transferred was proportional to the concentration of IgG in the maternal circuit ([IgG]m), but reached saturation at upper limits. With total [IgG]m at 6.5 g/l, 11.1 g/l or 26.2 g/l the increase in the fetal concentration of total IgG was 4.6 mg/l/h. 8.9 mg/l/h and 9.9 mg/l/h respectively. The rate of transfer of specific anti-D antibody to the fetal circuit was 0.026 IU/ml/h at a concentration of 38 IU/ml in the maternal circuit ([anti-D]m). High-dose therapeutic IVIgG added to the maternal circuit (total [IgG]m 29.2 g/l) significantly inhibited (P < 0.001) anti-D transfer to 0.004 IU/ml/n. Addition of the same IVIgG at a lower concentration (total [IgG]m 11.1 g/l) also reduced anti-D transfer, but only to 0.015 IU/l/h. The inhibitory effect of IVIgG does not appear to be mediated by anti-idiotypic or non-specific complexing with the anti-D, but may be the result of competition with IgG anti-D for placental Fc gamma receptors involved in the endocytotic uptake of IgG. The efficacy of IVIgG in this model suggests that it may be clinically useful in preventing HDN and other immune cytopenias, provided a sufficiently high dose is given.

Uptake of long chain fatty acids by human placental choriocarcinoma (BeWo) cells: role of plasma membrane fatty acid-binding protein.

In order to understand the mechanisms by which fatty acids are taken up by the placenta, the uptake of oleic, linoleic, arachidonic, and docosahexaenoic acids by cultured human placental choriocarcinoma (BeWo) cells was examined. Fatty acid uptake by BeWo cells was temperature-dependent and exhibited saturable kinetics. Oleic acid was taken up least and docosahexaenoic acid most by these cells. Moreover, competitive studies of fatty acid uptake by BeWo cells also indicated preferential uptake compared with oleic acid in the order of docosahexaenoic acid, arachidonic acid, and linoleic acid. Western blot analysis demonstrated that BeWo cells express a protein immunoreactive with antibodies to the human placental plasma membrane fatty acid-binding protein (p-FABPpm). Furthermore, pre-treatment of BeWo cells with these antibodies inhibited most of the uptake of docosahexaenoic (64%) and arachidonic acids (68%) whereas oleic acid uptake was inhibited only 32% compared with the controls treated with preimmune serum. These results clearly demonstrate that the pFABPpm may be involved in the preferential uptake of essential fatty acids (EFA) and their long chain polyunsaturated fatty acids (LCPUFA) by these cells. Studies on the distribution of radiolabeled fatty acids in the cellular lipids of BeWo cells showed that docosahexaenoic acid was incorporated mainly in the triacylglycerol fraction, followed by the phospholipid fraction, whereas for arachidonic acid the reverse was true. The preferential incorporation of docosahexaenoic acid into triacylglycerol suggests that triacylglycerol may play an important role in the placental transport of docosahexaenoic acid to the fetal circulation. Together these results demonstrate the preferential uptake of EFA/LCPUFA by BeWo cells that is most probably mediated via the pFABPpm. We thus propose that the p-FABPpm may be involved in the sequestration of maternal plasma LCPUFA by the placenta.

A rapid activation assay for human eosinophils based on adhesion to immobilized ICAM-1, VCAM-1 and IgG.

Interleukin 5 (IL-5) is a T-cell derived cytokine that induces eosinophil growth and differentiation in both mouse and human bone marrow cultures. Elevated levels of IL-5 as well as eosinophils have been detected in the sputum and Bronchoalveolar lavage (BAL) fluids of asthmatics. Since the recruitment of inflammatory cells to tissues requires the participation of adhesion molecules, we have developed a rapid and sensitive assay to examine the effect of IL-5 and other activation stimuli on eosinophil adhesion to recombinant intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1). Human recombinant IL-5, granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin 3 (IL-3), tumour necrosis factor alpha (TNF-alpha), RANTES, MCP-3, C5a, PAF, fMLP, PMA and ConA all induced adhesion of purified eosinophils obtained from normal donors to ICAM-1 and VCAM-1 in a dose and time dependent manner. Adhesion was rapid, within 15 minutes of culture at 37 degrees C, and plateaued within 30 minutes. Activated eosinophils also adhered rapidly to immobilized IgG via the type II Fc gamma receptor (CD32). Analysis of the effect of IL-5 on surface molecule expression by FACS analysis revealed increased expression of CD11b molecules and decreased expression of L-selectin, but no change in the expression of CD11a, CD18, CD29, CD49d and CD32. We also show that Mac-i plays an important role in the regulation of eosinophil activation, since antibodies to CD11b can block IL-5 induced adhesion to IgG and IL-5 induced degranulation.

Human placental cytochrome P450 and quinone reductase enzyme induction in relation to maternal smoking.

Components of cigarette smoke such as cadmium and polycyclic aromatic hydrocarbons have been shown to induce quinone reductase (QR) activity in placental explants. This study examines the relationship of maternal smoking habit and maternal plasma cotinine concentration with the activities in vitro of both QR and the cytochrome P450 (CYP1A) marker ethoxyresorufin O-deethylase (EROD) in placental tissue. Maternal plasma samples were taken at Week 34 of gestation, and placental tissues were obtained at term. Plasma cotinine concentrations were determined by high-performance liquid chromatography. Trophoblast cytosolic QR and microsomal EROD activities were measured by resazurin reduction and ethoxyresorufin O-dealkylation respectively. QR activity was inhibited 70% by a mixture of dicoumarol (1 microM) and rutin (20 microM). Plasma cotinine concentrations correlated significantly (P < 0.001) with both declared smoking rate (r = 0.67, N = 37) and placental EROD activity (r = 0.63, N = 36), but not with QR activity, whether measured as total QR activity or specifically as either DT-diaphorase or carbonyl reductase. It is concluded that smoking up to 40 cigarettes per day induces EROD but does not affect QR activity in the placenta at term.

Transfer of immunoglobulin G across the isolated perfused human placental lobule.

This study demonstrates that IgG transfer in vitro across the isolated perfused human placental lobule can be successfully studied by using natural forms of IgG. The transfer of anti-RhD IgG (anti-D) was measured in the presence and absence of intravenous immunoglobulin (IVIgG). When anti-D and IVIgG were present alone each crossed the placenta at about the same rate, but when both forms were present at the same time the movement of one interfered with the movement of the other. This pattern of transfer is consistent with receptor-mediated transcytosis. The interactions of IgG with trophoblastic transporters may therefore be studied without the complications that might arise from the use of conventionally labelled molecules.

Uptake of zinc by human placental microvillus border membranes and characterization of the effects of cadmium on this process.

The uptake of Zinc (Zn) by microvillus border membrane vesicles formed from the trophoblast of term human placentae is markedly increased over brief periods of incubation with much slower increases persisting for up to 2 h of incubation. Zinc is both bound to membrane components and transported into intravesicular osmotically active space. Uptake is saturable, temperature dependent from 4 to 37 degrees C with a Q10 of 1.7, and is inhibited by the sulphydryl agent DTNB. About 20 per cent of the uptake is susceptible to inhibition by Cadmium (Cd) at concentrations from 5 to 50 microM, a significant part of the action of this metal being on the transmembrane component of Zn uptake.

Identification of a thyroxine-containing self-epitope of thyroglobulin which triggers thyroid autoreactive T cells.

Although thyroglobulin (Tg), the thyroid prohormone, is well known as a T cell dependent autoantigen in human and experimental autoimmune thyroid disease, very little is known about the molecular basis of Tg recognition by T cells. In this paper, we have characterized the epitopes recognized by two clonotypically distinct, murine Tg autoreactive T cell hybridomas, CH9 and ADA2. In vitro iodination of a Tg preparation which was deficient in in vivo organified iodine was first used to confirm our previous observation that these T cells recognize iodination-related epitopes in the Tg molecule. Affinity chromatography of tryptic peptides derived from normally iodinated human Tg revealed that these epitopes were exclusively located in thyroxine (T4) containing peptides. Through the use of synthetic T4-containing peptides, representing the four major hormonogenic sites in Tg, we demonstrated that both CH9 and ADA2 recognize an epitope containing the T4 at position 2553 in human Tg. Sets of overlapping 5mer to 12mer peptides around this T4 showed that the most potent peptide was a 9mer beginning at Asp 2551. The T4 was shown to be a critical residue, since its replacement with any of the 20 naturally occurring amino acids produced only nonstimulatory peptides. Since the T cell hybridomas could also be stimulated by major histocompatibility complex class II positive (interferon-gamma-treated) thyroid epithelial cells in vitro, and their parent T cell lines can induce thyroiditis on adoptive transfer, the T4-containing Tg sequence described here is implicated as a pathogenic epitope in murine thyroid autoimmunity.

Parathyroid hormone-(1-34) peptide activates cyclic adenosine 3',5'-monophosphate in the human placenta.

Dually perfused human term placental lobules were exposed to forskolin, bovine parathyroid hormone (bPTH(1-34)) and human parathyroid hormone related-peptides, hPTHrP(1-34), hPTHrP(67-86)NH2 or PTHrP(107-138) for 15 min in the presence of 3-iso-butyl-1-methyl-xanthine (IBMX); control lobules were exposed to IBMX alone. Homogenates of these tissues were then assayed for cyclic adenosine 3',5'-monophosphate (cyclic AMP) and results normalized per mg of protein. Exposure to forskolin or bPTH(1-34) on both sides, and exposure to bPTH(1-34) at a concentration of 30 nM on the maternal side of the placenta or 120 nM on the fetal side of the placenta, significantly enhanced tissue cyclic AMP production compared with tissue exposed to IBMX alone. Exposure to hPTHrP(1-34), hPTHrP(67-86)NH2 and hPTHrP(107-138) at a concentration of 30 nM on both sides of the placenta had no significant effect upon tissue cyclic AMP production.