Molecular Testing for Bethesda III Thyroid Nodules: Trends in Implementation, Cytopathology Call Rates, Surgery Rates, and Malignancy Yield at a Single Institution

Background: Molecular testing (MT) has become standard practice to more accurately rule out malignancy in indeterminate Bethesda III (BIII) thyroid lesions. We sought to assess the adoption of this technology and its impact on cytology reporting, malignancy yield, and rates of surgery across community and academic sites affiliated with a tertiary medical center. Methods: We performed a retrospective cross-sectional study including all fine-needle aspirations (FNAs) analyzed at our institution from 2017 to 2021. We analyzed trends in MT utilization by platform and by community or academic site. We compared BIII call rates, MT utilization rates, rates of subsequent surgery, and malignancy yield on final pathology before and after MT became readily available using chi-square analysis and linear regression. Results: A total of 8960 FNAs were analyzed at our institution from 2017 to 2021. There was broad adoption of MT across both community and academic sites. There was a significant increase in both the BIII rate and the utilization of MT between the pre- and post-MT periods (p < 0.001 and p < 0.001). There was no significant change in the the malignancy yield on final pathology (57.1% vs. 50.0%, p = 0.347), while the positive predictive value of MT decreased from 85% to 50% (p = 0.008 [confidence interval 9.5-52.5% decrease]). Conclusions: The use of MT increased across the institution over the study period, with the largest increase seen after a dedicated pass for MT was routinely collected. This increased availability of MT may have led to an unintended increase in the rates of BIII lesions, MT utilization, and surgery for benign nodules. Physicians who use MT should be aware of potential consequences of its adoption to appropriately counsel patients.

A national study of postoperative thyroid hormone supplementation rates after thyroid lobectomy

BACKGROUND

The American Thyroid Association updated guidelines in 2015 to allow lobectomy for low-risk thyroid cancers. The objectives of this study were (1) to determine thyroid hormone supplementation rates after lobectomy and (2) to evaluate the effect of the American Thyroid Association guideline change on lobectomy and hormone supplementation rates among thyroid cancer patients.

METHODS

The Merative MarketScan Databases was used to identify adult (≥age 18) patients who underwent thyroidectomy for benign nodules or thyroid cancer. The association between indication for surgery and postoperative thyroid hormone supplementation was examined using χ2 analyses and multivariable logistic regression models. Among patients with thyroid cancer, lobectomy and hormone supplementation rates were compared in the periods before (2008-2015) and after the guideline change (2016-2019).

RESULTS

Of the 81,926 patients identified, 33,756 (41.2%) underwent thyroid lobectomy, 45,104 (55.1%) underwent total thyroidectomy, and 3,066 (3.7%) underwent completion thyroidectomy. Patients who underwent lobectomy for malignancy were significantly more likely to require hormone supplementation (59.3% vs 39.4% [P < .001], adjusted odds ratio 2.34 [95% confidence interval 2.20-2.48]) compared to those with benign disease. Compared to the 2008 to 2015 period, the proportion of patients who underwent lobectomy for thyroid cancer was higher in the 2016 to 2019 period (34.3% vs 30.3%, P < .001), with fewer patients requiring completion thyroidectomy (25.6% vs 29.8%, P < .001) and thyroid hormone supplementation (56.9% vs 60.1%, P = .04).

CONCLUSION

The postoperative thyroid hormone supplementation rate was significantly higher in patients who had thyroid cancers compared to benign diseases. After the American Thyroid Association guidelines changed, lobectomy rates increased significantly without a concomitant increase in the completion of thyroidectomy.

Does the Adoption of Molecular Testing Cause Decreased Thyroidectomy Rates in a National Cohort? A Quasiexperimental Study of High- Versus Low-Adoption States

Background: Over the last decade, the utilization of molecular testing (MT) for the evaluation of thyroid nodules has increased. Rates and patterns of adoption of MT and its effect on thyroidectomy rates nationally are unknown. Varying rates of MT adoption at the state level provide an opportunity to study the effects of MT on thyroidectomy rates using a quasiexperimental study design. Methods: We performed a retrospective analysis of American adult patients in the Merative™ MarketScan® Research Databases who underwent thyroid fine-needle aspiration (FNA) from 2011 to 2021. MT included commercially available DNA and RNA platforms and traditional targeted mutational analysis. Interrupted time series analysis was used to evaluate the inflection of MT adoption and thyroidectomy rates after 2015. Difference-in-differences (DID) analysis was used to causally analyze the effect of MT adoption on thyroidectomy rates in high-adoption (at least a 10% increase in MT utilization) versus low-adoption states (no more than 5% increase in MT utilization) from 2015 to 2021. Results: We identified 471,364 patients who underwent thyroid FNA. The utilization of MT increased over the study period from 0.01% [confidence interval, CI: 0.00% to 0.02%] to 10.1% [CI: 9.7% to 10.5%], in 2021, with an immediate (β2 = 1.61, p = 0.002) and deeper (β3 = 0.6, p < 0.001) increase in MT adoption after 2015. Utilization of MT was lower in black patients, the elderly, rural areas, and patients with Medicaid (p < 0.05). Thyroidectomy rates were inversely correlated with MT utilization (r = -0.98, p < 0.0001). From 2015 to 2021, the average MT utilization rate increased from 2.4% to 15.3% in high-adoption states and 1.6% to 5.6% in low-adoption states. In low-adoption states, thyroidectomy rates decreased more but to similar levels (18.5-13.2%) compared with high-adoption states (15.9-13.4%) with an adjusted DID rate of -3.3% [CI -5.6% to -0.8%]. Conclusions: The acceleration in adoption of MT after 2015 likely coincides with the publication of American Thyroid Association guidelines. Black, elderly, and rural patients are less likely to receive MT. Although thyroidectomy rates were inversely correlated with MT utilization, our study suggests that this correlation is not causal. The effect of MT on thyroidectomy rates may be overshadowed by decreasing aggressiveness of thyroid nodule evaluation.

Phenoxybenzamine is no longer the standard agent used for alpha blockade before adrenalectomy for pheochromocytoma: A national study of 552 patients

BACKGROUND

Phenoxybenzamine has been the standard agent for blockade before adrenalectomy for pheochromocytoma. However, high cost and limited availability have hampered its use. This study investigated whether other agents have supplanted the use of phenoxybenzamine as the first-line agent for alpha blockade in pheochromocytoma.

METHODS

We performed a retrospective analysis of patients in the IBM MarketScan Database who underwent adrenalectomy for pheochromocytoma (2008-2019). Patients were categorized as having been blocked with phenoxybenzamine, selective alpha blockers, calcium channel blockers and/or beta blockers, or none of the above. The outcomes included prescription costs, perioperative costs, and length of stay.

RESULTS

A total of 552 patients were identified; 58.7% were female, and the median age was 49 (interquartile range 40-57) years. In total, 291 (52.7%) patients were blocked with phenoxybenzamine, 114 (20.7%) with selective alpha blockers, 42 (7.6%) with only calcium channel blockers and/or beta blockers, and 76 (13.8%) with none. The proportion of patients blocked with phenoxybenzamine decreased from 71.0% in 2008 to 21.2% in 2019. The proportion of patients blocked with selective alpha blockers increased from 6.5% in 2008 to 42.4% and in 2019. The median cost of phenoxybenzamine increased from $722 (interquartile range $441-$1,514) in 2008 to $9,616 (interquartile range $5,049-$16,373) in 2019 (P < .001). Length of stay (2 [interquartile range 1-4] days vs 2 [interquartile range 0-3] days) and total perioperative costs ($24,250 [interquartile range $17,462-$33,849] vs $22,098 [interquartile range $16,341-$29,178] between phenoxybenzamine and selective alpha blocker groups were similar.

CONCLUSION

There has been a significant shift away from phenoxybenzamine for preoperative blockade before resection of pheochromocytoma. Selective alpha blockers and calcium channel blockers are increasingly used, likely due to reduced costs, without compromised length of stay or intensive care unit admission.

If the price is right: Cost-effectiveness of radiofrequency ablation versus thyroidectomy in the treatment of benign thyroid nodules

BACKGROUND

Radiofrequency ablation is an emerging technology in the United States to treat benign thyroid nodules. The cost-effectiveness of radiofrequency ablation in comparison with traditional thyroidectomy is unknown.

METHODS

A patient-level state transition microsimulation decision model was constructed comparing radiofrequency ablation with lobectomy in the management of benign thyroid nodules. Our base case was a 45-year-old woman with a solitary 30-cm³ nodule. Estimates of health utilities, complications, and mortality were obtained from the literature, and costs were estimated using Medicare reimbursement data. The primary outcomes of interest included total cost, quality-adjusted life years, and incremental cost-effectiveness ratios. All model estimates were subjected to 1-way sensitivity analyses to identify factors that strongly influence cost-effectiveness. A probabilistic sensitivity analysis was run across 1 million simulations to gauge outcome confidence with a willingness-to-pay threshold set at $100,000/quality-adjusted life year.

RESULTS

Radiofrequency ablation was assumed to cost $5,000, with an initial success rate of 78%. Patients with volume reduction ratio <50% underwent a second treatment of radiofrequency ablation. Radiofrequency ablation represented the dominant strategy, yielding 21.31 quality-adjusted life years for a total cost of $16,563 in comparison to lobectomy, which yielded 21.13 quality-adjusted life years for a total cost of $19,262. In a 1-way sensitivity analysis varying the cost of radiofrequency ablation across of range of values, the radiofrequency ablation strategy remained cost-effective until the cost of radiofrequency ablation exceeded $12,330 at willingness-to-pay $50,000 or $17,950 at willingness-to-pay $100,000.

CONCLUSION

Radiofrequency ablation is a cost-effective strategy in the treatment of benign thyroid nodules but is most sensitive to the cost of radiofrequency ablation.

Variations in the Course of the Carotid Arteries in Patients with Retropharyngeal Parathyroid Adenomas

The carotid arteries, classically described as taking a relatively straight course through the neck, deviate medially in a minority of patients. At the extreme, the internal carotid arteries may "kiss" in the midline, coming extremely close to the pharyngeal wall. In this clinical report, we describe 5 patients with primary hyperparathyroidism, all with ectopic retropharyngeal parathyroid adenomas but all with varying carotid artery anatomy. We describe these variations using a previously developed clinical grading system that highlights 1) the relationship between carotid artery location and risk of injury during pharyngeal procedures and 2) the importance of universal, objective criteria to classify carotid anatomy. Radiologists should be familiar with variations in carotid anatomy and communicate them to the operative team.

Genomics and climate change

Climate change is predicted to change the nature and distribution of global farming systems, and strategies will be needed to adapt and optimise global food-producing systems. If genomic technologies are to be useful in this scenario, there is a need for the careful definition of phenotypes and routine sample collection, as well as large-scale genotyping of animal populations. Genomic tools will greatly enhance the characterisation of available germplasm and exploration of local genetic resources, while faster and cheaper DNA sequencing is leading to an increased understanding of the underlying genetic basis of traits. The use of genomic tools to increase animal resilience, reduce methane emissions from cattle and sheep, improve disease resistance, decrease environmental impact, reduce competition for land and water and, finally, increase production may be the most feasible path for the future of livestock production. In this review, the authors discuss various genomic strategies in the light of climate change, focusing on the selection of resistant/tolerant animals, landscape genomics, metagenomics and gene editing.

Prevalence of enteropathogens in cats with and without diarrhea in four different management models for unowned cats in the southeast United States

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Most cats in shelters, sanctuaries, foster homes, and trap-neuter-return programs carried at least one enteropathogen.

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Tritrichomonas foetus and coronavirus were more common in cats with diarrhea.

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Other bacterial, viral, protozoal, and helminth enteropathogens were present in cats with normal feces and diarrhea.

The objective of this study was to determine the prevalence of enteropathogens in cats with and without diarrhea in four different models for managing unowned cats: short-term animal shelter, long-term sanctuary, home-based foster care, and trap-neuter-return. Fecal samples from 482 cats, approximately half of the cats with normal fecal consistency and half with diarrhea, were tested by zinc sulfate centrifugation and by real-time PCR for a panel of enteropathogens.

At least one enteropathogen of feline or zoonotic importance was detected in a majority of cats, regardless of management model. For most enteropathogens, the presence or absence of diarrhea was not significantly associated with infection, the exceptions being Tritrichomonas foetus in sanctuary cats with diarrhea (26%) and normal fecal consistency (10%), respectively (P ≤ 0.04), and feline coronavirus in foster cats (80% and 58%) (P ≤ 0.001). The types of enteropathogens detected were related to the type of management model, e.g., viral and protozoal infections were most common in shelters, sanctuaries, and foster homes (confinement systems), whereas helminth infections were most common in trap-neuter-return programs (free-roaming cats).

These results suggest that management practices for unowned cats are inadequate for control of enteropathogens and that the presence of diarrhea is a poor indicator of enteropathogen carriage. Risk-management strategies to reduce transmission to people and other animals should focus on sanitation, housing, compliance with preventive care guidelines, periodic surveillance, response to specific enteropathogens, humane population management of free-roaming community cats, public health education, and minimizing the duration and number of cats in mass confinement.

Bioeconomic model and selection indices in Aberdeen Angus cattle

A bioeconomic model was developed to calculate economic values for biological traits in full-cycle production systems and propose selection indices based on selection criteria used in the Brazilian Aberdeen Angus genetic breeding programme (PROMEBO). To assess the impact of changes in the performance of the traits on the profit of the production system, the initial values ​​of the traits were increased by 1%. The economic values for number of calves weaned (NCW) and slaughter weight (SW) were, respectively, R$ 6.65 and R$ 1.43/cow/year. The selection index at weaning showed a 44.77% emphasis on body weight, 14.24% for conformation, 30.36% for early maturing and 10.63% for muscle development. The eighteen-month index showed emphasis of 77.61% for body weight, 4.99% for conformation, 11.09% for early maturing, 6.10% for muscle development and 0.22% for scrotal circumference. NCW showed highest economic impact, and SW had important positive effect on the economics of the production system. The selection index proposed can be used by breeders and should contribute to greater profitability.

Humoral and cellular immunity in chromium picolinate-supplemented lambs

The effects of oral supplementation of chromium picolinate (CrPic) on humoral and cellular immunity in sheep were investigated. Twenty-four male lambs divided into four treatments and received different dosages of CrPic: placebo (0), 0.250, 0.375, and 0.500 mg of chromium/animal/day during 84 days. The base ration was Panicum maximum cv Massai hay and concentrate. Blood samples were collected fortnightly for total and differential leukocyte counts. On days 28 and 56, the lambs were challenged with chicken ovalbumin I.M. Serum samples were collected on days 46 and 74 and subjected to an indirect enzyme-linked immunosorbent assay to measure IgG anti-ovalbumin. The cell-mediated immune response was determined by a delay-type hypersensitivity test using phytohemagglutinin. CrPic did not significantly affect humoral immunity in lambs but there was a negative effect on cellular immunity (P < 0.05) as Cr supplementation increased. Therefore, the level of Cr supplementation for lambs must be better studied to address its effect on stressed animals or the possible toxic effects of Cr on the animal itself or its immune system.

Abstract 951: Preclinical evaluation of Xanthohumol in carcinoid cancer growth in vitro and in vivo

Background: Besides surgery, there is no potential curative treatment for carcinoid tumors. Because these cancers are metastatic in nature and produce excessive amounts of various bioactive hormones, patients diagnosed with this malignancy will have poor quality of life due to carcinoid syndrome. Therefore, new anticarcinogenic agents are required to improve the effectiveness of treatment. Xanthohumol (XN) (Tetrahydroxy-3′-prenylchalcone) is a prenylated chalconoid found in hops and beer that has been found to have potential anticancer and bioactive properties. Therefore, the purpose of this study was to evaluate the effectiveness of xanthohumol (XN) on carcinoid cancer growth in vitro and in vivo. Methods: To examine the anticancer activity of XN, we treated human gastrointestinal carcinoid BON and bronchopulmonary carcinoid H727 cells with up to 15 μmol/L of XN or carrier (DMSO), and analyzed the effect on cell growth by colony formation assay. The mechanism of growth inhibition was examined by flow cytometry and western analysis for the levels of pro-apoptotic and cell cycle regulatory proteins. To examine the anticancer activity of XN in vivo, subcutaneous BON carcinoid tumors developed in murine xenografts were subjected to intraperitoneal injections of XN (3 mg/kg bwt) or an appropriate volume of DMSO carrier every other day. Results: Treatment with xanthohumol significantly reduced the ability of carcinoid cells to form colonies in a dose-dependent manner. Flow cytometry and western analysis confirmed the observed decrease in cell viability, and showed the decrease was mediated through apoptosis. The carcinoid tumors in the mouse xenograft experiment showed a significant reduction in growth. Conclusions: XN treatment reduced cell viability, colony forming ability and increased cell death through apoptosis. In addition, administration of XN suppressed cancer cell growth in an in vivo xenograft mouse model. Our findings demonstrate for the first time the anti-proliferative effects of xanthohumol in carcinoid cell lines in vivo. Xanthohumol is already being used as a dietary supplement to encourage overall health and has shown few side effects. This fact combined with the potential anticarcinogenic activity found here warrants clinical investigation on patients with carcinoid disease.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 951. doi:1538-7445.AM2012-951

Genetic variability in local Brazilian horse lines using microsatellite markers

Genetic variability at 11 microsatellite markers was analyzed in five naturalized/local Brazilian horse breeds or genetic groups. Blood samples were collected from 328 animals of the breeds Campeira (Santa Catarina State), Lavradeira (Roraima State), Pantaneira (Pantanal Mato-Grossense), Mangalarga Marchador (Minas Gerais State), as well as the genetic group Baixadeiro (Maranhão State), and the exotic breeds English Thoroughbred and Arab. We found significant genetic variability within evaluated microsatellite loci, with observed heterozygosis varying between 0.426 and 0.768 and polymorphism information content values of 0.751 to 0.914. All breeds showed high inbreeding coefficients and were not in Hardy-Weinberg equilibrium. The smallest genetic distance was seen between the Pantaneira and Arab breeds. The principal component analyzes and Bayesian approach demonstrated that the exotic breeds have had a significant influence on the genetic formation of the local breeds, with introgression of English Throroughbred in Pantaneira and Lavradeira, as well as genetic proximity between the Arab, Pantaneira and Mangalarga Marchador populations. This study shows the need to conserve traits acquired by naturalized horse breeds over centuries of natural selection in Brazil due to the genetic uniqueness of each group, suggesting a reduced gene flow between them. These results reinforce the need to include these herds in animal genetic resource conservation programs to maximize the genetic variability and conserve useful allele combinations.

Adaptation of a low-cost medium-throughput genotyping system for ovine prion protein gene polymorphims associated with scrapie

Resistance and susceptibility to scrapie in sheep have been associated with SNPs located at codons 136, 154 and 171 of the prion protein (PRNP) gene. Many countries have sheep breeding programs selecting for resistance to scrapie based on the genotyping of these SNPs. We adapted a fast and robust method for genotyping sheep flocks for these polymorphisms, with reduced costs. Ninety-six samples were genotyped using an adapted SNaPshot PRNP assay, and the results were checked by resequencing. The results showed 100% concordance, using a method that reduces genotyping costs by 70%, by reducing reagent concentrations in the three main steps of the assay (amplicon purification, base extension and final cleanup). This cost reduction should contribute to the development of selection criteria based on PRNP genotyping in countries where assay costs are an important limiting factor.

An analysis of the 1978 African swine fever outbreak in Brazil and its eradication

The aim of this paper is to evaluate the African swine fever (ASF) outbreak that began in 1978 in Paracambi municipality, Rio de Janeiro State, Brazil, and the steps taken by the Brazilian authorities to eradicate the disease. The presence of ASF in the country was confirmed by isolating the virus, and its pathogenicity was certified by the laboratory of the Plum Island Disease Center, New York, United States. Even before the laboratory results became available, the Brazilian Agriculture Ministry declared an Animal Health Emergency, in which the official Veterinary Services adopted rapid control measures to restrain and eradicate the disease. These control measures contributed to the reorganisation of the national swine industry and stimulated the use of high-technology production techniques, as well as an improvement in herd health consciousness. All this contributed to Brazil becoming the largest meat exporter in the world.

Performance and ruminal protozoa in lambs with chromium supplementation

The effects of chromium picolinate (CrPic) oral supplementation on the performance and ruminal protozoa population in sheep was investigated. Twenty-four male lambs were treated with four different levels of CrPic: placebo, 0.250, 0.375 and 0.500mg of chromium/animal/day during 84 days. The base ration was Panicum maximum cv Massai hay and concentrate. Feed intake was measured three times a week. Lambs were weighed every 2 weeks. Ruminal content was sampled five times during the trial to quantify ruminal protozoa. No difference (p>0.05) between treatments was recorded for any parameter measured: initial and final mean body weight, dry matter intake, daily gain and total body weight gain. There was a negative linear relationship between Cr supplementation and protozoa count (p=0.0013) with no additional decrease when CrPic supplemental levels were higher than 0.375mg/day. Therefore, Cr supplementation must be carried out carefully and more studies need to address stressed animals or possible toxic effects of Cr in the animal itself or to the ruminal protozoa population.

Effects of condensed tannin from Acacia mearnsii on sheep infected naturally with gastrointestinal helminthes

The effect of tannins on endoparasite control in hair sheep was investigated using 20 entire lambs of the Santa Inês breed. At the beginning of the experiment these animals were 6-months old and weighed 22.5kg+/-4.7. The treatments used were (10 animals each): GT (animals receiving 18g of Acácia negra containing 18% of condensed tannin/animal/week) and GC (animals not receiving tannin). The experiment lasted 84 days, with animals kept on an Andropogon gayanus pasture. Faeces were collected weekly, with weighing and blood collection carried out fortnightly. At slaughter, the adult worms were harvested for identification and counting. Although the GT animals weighed more than the GC lambs at slaughter, these differences were not significant (P>0.05). In general, the values for haemoglobin, hematocrit, total protein, urea, phosphorus and calcium in the serum were within normal levels and no significant differences between groups were observed. For faecal egg count (FEC), lower values were observed throughout the experiment in the group receiving tannin, but these differences were only significant in the eighth week. There was a lower output of eggs by regression for GT compared with GC (P<0.05). The species identified, in decreasing order of worm count, were: Trichostrongylus colubriformis, Haemonchus contortus, Oesophagostomum columbianum, Cooperia sp., Strongyloides papillosus, Trichuris globulosa and Moniezia expansa. The total worm count and number of each species of worm were lower for GT compared with GC for T. colubriformis and Cooperia sp. (P<0.05). Condensed tannin (CT) from A. negra had an antiparasitic effect, thereby representing an alternative for worm control in sheep.

Influence of protein supplementation on the resistance and resilience on young hair sheep naturally infected with gastrointestinal nematodes during rainy and dry seasons

Thirty, 4-month-old entire Santa Ines lambs were grazed on an Andropogon gayanus pasture, during a 34-week period (rainy season weeks 0-20 and dry season weeks 21-34) and allocated in two treatment groups (n = 15) each with different protein supplementation: high protein (HP-19% CP) and low protein (LP-11% CP). These were subdivided into those receiving anthelmintic treatment (c) (n = 7) and without anthelmintic treatment (i) (n = 8). The objective was to evaluate the effects of supplementation with protein on resistance and resilience to natural helminth infection of hair breed lambs. Lamb weight, blood collection and faecal egg counts (FEC) were carried out monthly. The lambs were slaughtered after 34 weeks, when worm burdens, worm length and eosinophil cell counts were taken. The sheep on treatments HPc and HPi were heavier in live weight than those from LPi and LPc (P < 0.05) at the end of the rainy period. The HPc group finished heavier (P < 0.05) than the other groups in the dry season, which had no significant differences between them. The predominant species of nematode found was T. colubriformis followed by H. contortus, Trichuris globulosa and Moniezia expansa. Animals on HPi had lower FEC than LPi (P < 0.05). The number of worms was lower for both HP groups (P < 0.05) with worm length shorter in the HPc group (P < 0.05) compared with all other groups. The number of eosinophils was higher in animals in the LPi group, which also showed anaemia and lower plasma urea at the end of the dry season. Diet supplementation with high protein was able to improve resilience and resistance to natural infection by endoparasites during the rainy season. In the dry season there was a decrease in both of these traits, which were intimately linked to the quality of available forage under tropical conditions.

Short chain fatty acids stimulate feline colonic smooth muscle contraction

The effect of short chain fatty acids (SCFA) on feline colonic smooth muscle contraction was evaluated in vitro. Colonic tissue was obtained from seven healthy male and female adult cats and seven healthy male and female kittens. Longitudinal and circular colonic smooth muscle strips from proximal and distal colon were incubated with SCFA (acetate, butyrate and propionate; 1-100mM). SCFA-induced contractions were compared to responses obtained using maximal concentrations (10(-4)M) of acetylcholine (ACh). The calcium dependence of the SCFA response was investigated by incubating with nifedipine (1 microM) or verapamil (1 microM). Acetate, butyrate and propionate elicited isometric stress responses (0.25-1.98 x 10(4)N/m(2)) in longitudinal, but not circular, smooth muscle from both the proximal and distal colon of adult cats. Maximal responses were attained at 50 and 100mM SCFA. Maximal butyrate and propionate responses were 29 and 19% of the maximal ACh response (10(-4)M), respectively. Acetate was least effective in stimulating contractile responses. Nifedipine and verapamil abolished all responses. Contractile responses in kittens were similar to those observed in adult cats, but were smaller in amplitude. Results of these studies have shown that SCFA stimulate longitudinal colonic smooth muscle contractions in kittens and adult cats in vitro. These SCFA-induced contractions involve activation of calcium influx. These in vitro findings may account for some of the effects of dietary fiber on feline colonic motility in vivo.

HIV envelope gp120 activates human arterial smooth muscle cells

There have been increasing reports of acute coronary thrombotic events in patients with HIV. Although these clinical events have been attributed primarily to dyslipidemia associated with protease inhibitor therapy, autopsy studies in children with HIV suggest the presence of an underlying arteriopathy. This study demonstrates that the HIV envelope protein, gp120, activates human arterial smooth muscle cells to express tissue factor, the initiator of the coagulation cascade. The induction of tissue factor by gp120 is mediated by two biologically relevant coreceptors for HIV infection, CXCR4 and CCR5, and is also dependent on the presence of functional CD4. Induction of tissue factor by gp120 requires activation of mitogen-activating protein kinases, activation of protein kinase C, and generation of reactive oxygen species, signaling pathways that have protean effects on smooth muscle cell physiology. The activation of smooth muscle cells by gp120 may play an important role in the vascular, thrombotic, and inflammatory responses to HIV infection.

Expression and coreceptor function of APJ for primate immunodeficiency viruses

APJ is a seven transmembrane domain G-protein-coupled receptor that functions as a coreceptor for some primate immunodeficiency virus strains. The in vivo significance of APJ coreceptor function remains to be elucidated, however, due to the lack of an antibody that can be used to assess APJ expression, and because of the absence of an antibody or ligand that can block APJ coreceptor activity. Therefore, we produced a specific monoclonal antibody (MAb 856) to APJ and found that it detected this receptor in FACS, immunofluorescence, and immunohistochemistry studies. MAb 856 also recognized APJ by Western blot, enabling us to determine that APJ is N-glycosylated. Using this antibody, we correlated APJ expression with coreceptor activity and found that APJ had coreceptor function even at low levels of expression. However, we found that APJ could not be detected by FACS analysis on cell lines commonly used to propagate primate lentiviruses, nor was it expressed on human PBMC cultured under a variety of conditions. We also found that some viral envelope proteins could mediate fusion with APJ-positive, CD4-negative cells, provided that CD4 was added in trans. These findings indicate that in some situations APJ use could render primary cell types susceptible to virus infection, although we have not found any evidence that this occurs. Finally, the peptide ligand for APJ, apelin-13, efficiently blocked APJ coreceptor activity.

Expression of multiple functional chemokine receptors and monocyte chemoattractant protein-1 in human neurons

Functional chemokine receptors and chemokines are expressed by glial cells within the CNS, though relatively little is known about the patterns of neuronal chemokine receptor expression and function. We developed monoclonal antibodies to the CCR1, CCR2, CCR3, CCR6, CXCR2, CXCR3 and CXCR4 chemokine receptors to study their expression in human fetal neurons cultured from brain tissue as well as the clonally derived NT2.N human neuronal cell line (NTera 2/cl.D1). Specific monoclonal antibody labeling demonstrated expression of CCR2, CXCR2, CXCR3 and CXCR4 on neurons from both sources. Co-labeling studies revealed strong expression of CXCR3 and CXCR4 on both dendritic and axonal processes, with a weaker expression of CXCR2 and CCR2. Reverse transcriptase-polymerase chain reaction analysis of pure NT2.N neurons confirmed RNA expression for CCR2, CXCR2, CXCR3 and CXCR4. No changes in the neuronal labeling pattern of chemokine receptor expression were noted when NT2.N neurons were grown on a supporting layer of astrocytes, again consistent with similar patterns seen in primary human fetal brain cultures. Analysis of single-cell calcium transients revealed a robust response to stromal derived factor-1alpha (CXCR4) and melanocyte growth-stimulating activity (CXCR2), and variable response to monocyte chemoattractant protein-1 (CCR2) or interferon-gamma inducible protein-10 (CXCR3). Finally, we detected the release of monocyte chemoattractant protein-1 from pure cultures of NT2.N neurons, but not undifferentiated NT2 cells. These data indicate that individual neurons may not only co-express multiple functional chemokine receptors, but also that neurons themselves produce chemokines which may influence cellular function within the central nervous system.

Mechanisms of leukocyte trafficking into the CNS

HIV-1 encephalitis occurs in up to one-third of HIV-1-infected individuals. The mechanisms through which this pathology develops are thought to involve viral passage across the blood-brain barrier (BBB), as well as entry of HIV-infected and/or uninfected inflammatory cells into the central nervous system (CNS). Viral proteins and cytokines may also contribute to the pathogenesis of encephalitis. We show that the chemokines SDF-1 and MCP-1 induce transmigration of uninfected human lymphocytes and monocytes across our model of the BBB, a co-culture of human fetal astrocytes and endothelial cells. We also demonstrate that the HIV-1 protein Tat induces adhesion molecule expression and chemokine production by human fetal astrocytes and microglia, which could further contribute to leukocyte entry into the CNS. Finally, our data indicate that inflammatory cytokines modulate the expression of CXCR4, a co-receptor for HIV-1, on human fetal astrocytes, suggesting that these cytokines may potentially modulate the infectability of astrocytes by HIV-1. These findings support the hypothesis that there may be several different mechanisms that contribute to the development and progression of HIV-1 encephalitis.

Chemokine and chemokine-receptor expression in human glial elements: induction by the HIV protein, Tat, and chemokine autoregulation

Human immunodeficiency virus (HIV) encephalitis is a prominent pathology seen in children infected with HIV. Immunohistochemical analyses of pediatric brain tissue showed distinct differences in expression of C-C chemokines and their receptors between children with HIV encephalitis and those with non-CNS-related pathologies. Evidence suggests that soluble factors such as HIV Tat released from HIV-infected cells may have pathogenic effects. Our results show Tat effects on chemokines and their receptors in microglia and astrocytes as well as chemokine autoregulation in these cells. These results provide evidence for the complex interplay of Tat, chemokines, and chemokine receptors in the inflammatory processes of HIV encephalitis and illustrate an important new role for chemokines as autocrine regulators.

Human vascular smooth muscle cells possess functional CCR5

CC chemokine receptors are important modulators of inflammation. Although CC chemokine receptors have been found predominantly on leukocytes, recent studies have suggested that vascular smooth muscle cells respond to CC chemokines. We now report that human smooth muscle cells express CCR5, a co-receptor for human immunodeficiency virus. CCR5 mRNA was detectable by RNA blot hybridization in human aortic and coronary artery smooth muscle cells. The cDNA generated by reverse transcription-polymerase chain reaction from aortic smooth muscle cells had 100% identity throughout the entire coding region with the CCR5 cloned from THP-1 cells. By immunohistochemistry, CCR5 and the CCR5 ligand, macrophage inflammatory protein-1beta (MIP-1beta), were detected in smooth muscle cells and macrophages of the atherosclerotic plaque. In smooth muscle cell culture, MIP-1beta induced a significant increase in intracellular calcium concentrations, which was blocked by an antibody to CCR5. In addition, MIP-1beta caused a calcium-dependent increase in tissue factor activity. Tissue factor is the initiator of coagulation and is thought to play a key role in arterial thrombosis. These data suggest that human arterial smooth muscle cells express functional CCR5 receptors and MIP-1beta is an agonist for these cells.

Differential induction of chemokines in human microglia by type I and II interferons

Chemokines are secreted proteins that function as chemoattractants, mediating the recruitment of specific subsets of leukocytes to sites of tissue damage and immunological reactions. Chemokines may also function as antiviral agents, since viruses such as human immunodeficiency virus type 1 (HIV-1) use chemokine receptors as co-receptors for viral entry. This study examines whether virus-induced interferon, IFNbeta, or immune-related interferon, IFNgamma, affects the production of beta-chemokines by CNS microglia and peripheral monocytes. When IFNbeta was used as the stimulus, induction of MIP-1alpha, MIP-1beta, MCP-1, and RANTES mRNA and protein was observed within 12 h of stimulation in microglia. By contrast, when IFNgamma was used as the stimulus, only MCP-1 was induced. IFNbeta stimulation of blood monocytes resulted in upregulation of MIP-1alpha, MIP-1beta, and MCP-1. Thus, type I and II interferons differentially regulate beta-chemokines in human fetal microglia and peripheral blood monocytes. These observations may have relevance for the therapeutic activity of IFNbeta in multiple sclerosis and for the antiviral effects of IFNbeta for HIV-1 infection of monocytes and microglia.

Transthoracic needle aspiration biopsy: variables that affect risk of pneumothorax

PURPOSE

To analyze the influence of multiple variables on the rate of pneumothorax and chest tube placement associated with transthoracic needle aspiration biopsy of the lung.

MATERIALS AND METHODS

In 346 patients, 331 computed tomographically (CT) guided and 24 fluoroscopically guided lung biopsies were performed. Variables analyzed were lesion size, depth, and location; number of pleural passes; needle size; presence of emphysema; and training level of the person who performed the biopsy.

RESULTS

Pneumothorax occurred at 144 (40.4%) of 356 biopsies, including 139 (42.0%) CT-guided and five (21%) fluoroscopically guided biopsies. Chest tube placement was needed in 25 (17.4%) of 144 cases of pneumothorax (7% of all biopsies). An increased rate of pneumothorax was correlated with smaller lesion size (P = .001) and presence of emphysema (P = .01). Patients with emphysema were three times as likely to require chest tube placement. The pneumothorax rate was 15% (16 of 105) if no aerated lung was traversed and approximately 50% if aerated lung was penetrated. Lesion location, needle size, number of pleural passes, and level of training were not correlated with pneumothorax rate.

CONCLUSION

Smaller lesion size and emphysema are strongly correlated with occurrence of pneumothorax. Pneumothorax was more than three times less frequent if no aerated lung was traversed. After pneumothorax, chest tube placements were related to the presence of emphysema.

Cytokine induction of MIP-1 alpha and MIP-1 beta in human fetal microglia

Leukocyte infiltration into the central nervous system (CNS) is a key event in the inflammatory processes of neuroimmunologic diseases. Microglia, resident macrophages of the CNS, may contribute to this process by elaborating chemoattractants that are capable of recruiting leukocytes across the blood-brain barrier. Such factors have been detected in the CNS of animal models of multiple sclerosis and in the brains of human and nonhuman primates with AIDS encephalitis. As the expression of these chemoattractants may play an important role in the initiation and progression of neuroimmunologic diseases, we analyzed expression of the chemokines MIP-1 alpha, MIP-1 beta, MCP-1, and RANTES in human fetal microglial cultures. Unstimulated microglia expressed minimal levels of MIP-1 alpha, MIP-1 beta, and MCP-1, while RANTES was undetectable. In response to LPS, TNF-alpha, or IL-1 beta, both MIP-1 alpha and MIP-1 beta were induced at the mRNA and protein levels in a dose- and time-dependent manner. IFN-gamma did not significantly induce chemokine expression. MCP-1 was detectable in LPS- and cytokine-treated microglia. TGF-beta, a cytokine with down-modulatory effects on other cell types, had little effect on chemokine expression in microglia when used concomitantly before or during treatment with LPS. These results illustrate the ability of certain inflammatory stimuli to induce expression of MIP-1 alpha, MIP-1 beta, and MCP-1 by human fetal microglia. The expression of these chemoattractants may function to recruit inflammatory cells into the CNS during the course of neuroimmunologic diseases and may modulate the ability of HIV to infect the CNS.

Heartburn correlated to 24-hour pH monitoring and radiographic examination of the esophagus

OBJECTIVES

Study relationship of gastroesophageal reflux disease to findings on radiographic examination of the esophagus.

METHODS

We correlated heartburn (HB) in 360 patients (174 women; 186 men; mean age, 53 yr) to results of pH monitoring (pHM) and radiographic examination of the esophagus. Radiographic findings were categorized as normal (n = 129), hiatal hernia (HH) only (n = 173), reflux esophagitis (n = 50), or peptic stricture (n = 8) (ES; 58). Abnormal pHM was defined as total percentage of esophageal acid exposure time (pH < 4) of 6% or greater.

RESULTS

pHM was abnormal in 41 (31%) of 132 patients with HB versus 54 (24%) of 228 without the symptom (p > 0.05). Radiographic correlation showed abnormal pHM in only 21 (16%) of 129 patients with a normal esophagus, 52 (30%) of 173 with HH, and 22 (38%) of 58 with ES, which was significantly lower for those with a normal esophagus. In 132 patients with HB, those with normal esophagus had lower abnormal pHM (2 of 38; 5%) compared with patients with HH (24 of 64; 38%) or with ES (15 of 30; 50%) (p < 0.05). In the 228 patients without HB, abnormal pHM was found in 19 (21%) of 91 with a normal esophagus, 28 (26%) of 109 with HH, and 7 (25%) of 28 with ES (p > 0.05).

CONCLUSIONS

(1) pHM findings did not correlate with presence or absence of HB; (2) pHM is usually normal in patients with normal esophagus on RE; (3) pHM is also usually normal in patients with HB and normal esophagus on RE; and (4) pHM is often normal in patients with radiographic findings of reflux esophagitis or peptic stricture.