Organ Boundary Circuits Regulate Sox9+ Alveolar Tuft Cells During Post-Pneumonectomy Lung Regeneration

Tissue homeostasis is controlled by cellular circuits governing cell growth, organization, and differentation. In this study we identify previously undescribed cell-to-cell communication that mediates information flow from mechanosensitive pleural mesothelial cells to alveolar-resident stem-like tuft cells in the lung. We find mesothelial cells to express a combination of mechanotransduction genes and lineage-restricted ligands which makes them uniquely capable of responding to tissue tension and producing paracrine cues acting on parenchymal populations. In parallel, we describe a large population of stem-like alveolar tuft cells that express the endodermal stem cell markers Sox9 and Lgr5 and a receptor profile making them uniquely sensitive to cues produced by pleural Mesothelium. We hypothesized that crosstalk from mesothelial cells to alveolar tuft cells might be central to the regulation of post-penumonectomy lung regeneration. Following pneumonectomy, we find that mesothelial cells display radically altered phenotype and ligand expression, in a pattern that closely tracks with parenchymal epithelial proliferation and alveolar tissue growth. During an initial pro-inflammatory stage of tissue regeneration, Mesothelium promotes epithelial proliferation via WNT ligand secretion, orchestrates an increase in microvascular permeability, and encourages immune extravasation via chemokine secretion. This stage is followed first by a tissue remodeling period, characterized by angiogenesis and BMP pathway sensitization, and then a stable return to homeostasis. Coupled with key changes in parenchymal structure and matrix production, the cumulative effect is a now larger organ including newly-grown, fully-functional tissue parenchyma. This study paints Mesothelial cells as a key orchestrating cell type that defines the boundary of the lung and exerts critical influence over the tissue-level signaling state regulating resident stem cell populations. The cellular circuits unearthed here suggest that human lung regeneration might be inducible through well-engineered approaches targeting the induction of tissue regeneration and safe return to homeostasis.

Case report of congenital intestinal malrotation in an adult discovered three months status-post appendectomy

Introduction and importance

Intestinal malrotation is a congenital anomaly primarily diagnosed in children, with limited cases reported in adults. Prompt recognition is necessary to prevent life-threatening complications including bowel ischemia and death. We present a rare case of adult intestinal malrotation highlighting difficulty in diagnosis and surgical management.

Case presentation

A 37-year-old Caucasian woman presented with a 3-day history of worsening diffuse abdominal pain, three months status-post laparoscopic appendectomy. CT scan with contrast of the abdomen and pelvis demonstrated small bowel mesenteric swirling and descending duodenal transition point. Differential diagnosis included intestinal malrotation versus small bowel obstruction. Pre-operatively, the patient expressed frustration with years of abdominal pain and lack of improvement. Treatment with open surgical small bowel detorsion and ligation of the Ladd's bands was performed, after initial laparoscopic intervention was complicated by enterotomy. The patient recovered well post-operatively with final diagnosis of intestinal malrotation with midgut volvulus. Discharge home was delayed due to polysubstance withdrawal. Post-operatively, the patient reported immediate relief of symptoms which persisted at 2-week and 2-month follow-ups.

Clinical discussion

Few reports of congenital malrotation diagnosed in adulthood are reported. This highlights the importance of evaluating all patients for malrotation when the appendix is found outside of the normal positioning in the RLQ, as surgical correction of malrotation is of utmost importance in such patients.

Conclusion

Clinicians should consider intestinal malrotation in adults with recurrent vague abdominal symptoms. To our knowledge, this is the first report of congenital malrotation discovered in an adult after prior appendectomy.

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Congenital intestinal malrotation diagnosed in adults is scarcely reported.

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No guidelines exist for the management of malrotation in adult patients.

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To our knowledge, this is the first report of intestinal malrotation discovered after previous appendectomy.

Long-term social dysfunction after trauma: What is the prevalence, risk factors, and associated outcomes?

BACKGROUND

Social functioning-the ability to participate in organized or informal family, friend, or peer groups and communal activities-is intertwined with physical and emotional health. Although trauma can have a lasting effect on both the physical and emotional well-being of patients, little is known about the long-term impact of injury on social functioning. We sought to determine the prevalence of, risk factors for, and outcomes associated with long-term social dysfunction after trauma.

METHODS

Adults with moderate-to-severe injuries managed at three Level I trauma centers were contacted at 6 to 12 months after injury to inquire about social dysfunction. Demographics, socioeconomic parameters, and injury-related and hospital course information were also obtained. A stepwise backward logistic regression model was fitted to determine independent risk factors of social dysfunction, and multiple logistic regression models were used to determine associations between social dysfunction and post-traumatic stress disorder, functional limitations, and return to work.

RESULTS

Of the 805 screened patients, 45.2% reported social dysfunction. Patients with social dysfunction were more likely to be African American, be Medicaid beneficiaries, be of lower education, require mechanical ventilation, be discharged less often to home, have a lower mean age and had longer hospital stays. In multivariable analysis, low education, longer hospital stay, past psychiatric illness, and African-American race independently increased the risk for social dysfunction. Furthermore, patients with social dysfunction were more likely to screen positive for post-traumatic stress disorder (odds ratio: 16.25 [95% confidence interval: 9.49-27.85]), be experiencing functional limitations (odds ratio: 2.80 [95% confidence interval: 1.76-4.44]), and to not have returned to work (odds ratio: 5.65 [95% confidence interval: 3.92-8.14]).

CONCLUSION

Lower educational attainment, long hospital stay, past pyschiatric illness, and African-American race appear to predispose to social dysfunction after trauma, which in turn is associated with a positive post-traumatic stress disorder screen, functional limitations, and delayed return to work.

Molecular diversity of bovine viral diarrhea virus in uruguay

Bovine viral diarrhea (BVD) affects bovine production and reproduction causing significant economic losses all over the world. Two viral species has been recognized: BVDV-1 and BVDV-2, both distributed worldwide. Recently, novel specie of BVDV named HoBi-like pestivirus was discovered. The presence of BVDV was confirmed in 1996 in Uruguay, however, does not exist until today a schedule of compulsory vaccination along the country. Serological studies with samples from all Uruguayan herds were performed during 2000 and 2001 demonstrating that all of them were seropositive to BVDV with a mean prevalence of 69%. In addition, there have been no new studies done since those previously described and it is important to mention that the genetic diversity of BVD has never been described in Uruguay. Nowadays, there is strongly suspect that BVDV is one of the most important causes of reproductive failures in our herds. The aim of this study was to describe for the first time in Uruguay the genetic diversity of BVDV with samples collected from different regions along the country. Serological status of 390 non-vaccinated animals against BVDV with reproductive problems from farms of Rivera, Tacuarembó and Florida departments of Uruguay were studied. All herds were seropositive to BVDV and high proportion of animals were positive (298/390), while 4.1% (16/390) of the animals were positive to Antigen Capture ELISA test and Real Time PCR. Phylogenetic analysis performed with concatenated sequences from the 5'UTR and Npro genomic regions revealed that BVDV-1 and BVDV-2 are infecting our herds, being BVDV-1 the most frequently found. The major subtype was BVDV-1a, followed by BVDV-1i and BVDV-2b. This is the first study that describes the genetic diversity of BVDV in Uruguay and it will contribute to the elaboration of sanitization programs.

Screening of antimutagenicity via antioxidant activity in Cuban medicinal plants

The reducing activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, z.rad;OH radical scavenging potential, in vitro inhibition of lipid peroxidation and modulation of mutagenicity induced by ter-butyl hydroperoxide (TBH) in Escherichia coli were sequentially screened in 45 species of plants used with medicinal purposes in Cuba, in a search for antioxidant agents which protect DNA against oxidative stress.Five species, e.g. Tamarindus indica L., Lippia alba L., Pimenta dioica (L.) Merr, Rheedia aristata Griseb. and Curcuma longa L. displayed IC(50)<30 micro g/ml in the DPPH radical reduction assay and IC(50)<32 micro g/ml in lipid peroxidation inhibition testing. Pimenta dioica and Curcuma longa L. showed also a 20% inhibition of the in vitro induced z.rad;OH attack to deoxyglucose. Further antimutagenesis assay in Escherichia coli IC 188 evidenced that only Pimenta dioica prevents DNA damage by TBH to the test bacteria. A role of antioxidant enzymes is presumed in this case, as judged by a different response in the isogenic Escherichia coli IC 203 deficient in catalase and alkyl hydroperoxide reductase and the discrete inhibition of oxidative mutagenesis also observed when pre-treatment of the extract was assayed. Eugenol, the main constituent of the essential oil of Pimenta dioica, also inhibited oxidative mutagenesis by TBH in Escherichia coli, at concentrations ranging from 150 to 400 micro g/plate.

Occurrence of clinical and sub-clinical mastitis in dairy herds in the West Littoral Region in Uruguay

Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20 degrees C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300,000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%.

Assessment of mutagenicity in Parthenium hysterophorus L

The mutagenic potential of a crude extract of Parthenium hysterophorus L. was assessed in the Salmonella/microsome (Ames) assay and the mouse bone marrow micronucleus test. Results in the bacterial mutagenicity assay were negative for the five strains employed, e.g. TA 1535, TA1537, TA 98, TA 100 and TA 102, while cytotoxicity was evident in all cases at 5000 microg per plate, the highest concentration assayed. A decrease in toxicity was observed with exogenous mammalian metabolic activation (S9) or glutathione (5 micromol per plate). When mutagenicity was monitored after column chromatography fractionation of the crude, fraction 1 was mutagenic in strain TA 98 (+S9). Besides, cytotoxicity was found in fraction 5, where parthenin was eluted. The micronucleus test was negative in mice upon oral administration, at doses up to 96 mg of crude per kg. Bone marrow toxicity was not observed. The crude extract exhibited some in vitro pro-oxidant activity. It also inhibited lipid peroxidation (IC(50)=4.1 microg/ml) but failed to act as .OH scavenger.

Anagallis arvensis poisoning in cattle and sheep in Uruguay

Outbreaks of Anagallis arvensis poisoning were observed from 1994 to 1998 in cattle and sheep in Uruguay during December and January. Cattle morbidity varied between 3.2 and 53.2% and lethality 42.6 and 100%. Sheep morbidity was 2.8 to 42.9% and lethality 81.3 to 100%. Nine outbreaks occurred on barley and wheat stubble, and 1 in a field previousy ploughed but not cultivated. Clinical signs were weakness, staggers, diarrhea (sometimes bloody), coma, and death. Serum levels of creatinine and urea were elevated. Gross lesions were characterized by sc petechiae, fluid in body cavities, mesenteric and perirenal edema, yellowish or pale kidneys with petechiae on the cortex, esophageal erosive lesions or ulcers, and hemorrhagic abomasitis and enteritis. Severe nephrosis was observed histologically. The green plant collected in a field where an outbreak occurred was administered to 2 sheep at doses of 160 and 224 g/kg bw and produced clinical signs and pathology similar to those observed in field cases.

Structural model of antagonist and agonist binding to the angiotensin II, AT1 subtype, G protein coupled receptor

BACKGROUND

The family of G protein coupled receptors is the largest and perhaps most functionally diverse class of cell-surface receptors. Due to the difficulty of obtaining structural data on membrane proteins there is little information on which to base an understanding of ligand structure-activity relationships, the effects of receptor mutations and the mechanism(s) of signal transduction in this family. We therefore set out to develop a structural model for one such receptor, the human angiotensin II receptor.

RESULTS

An alignment between the human angiotensin II (type 1; hAT1), human beta 2 adrenergic, human neurokinin-1, and human bradykinin receptors, all of which are G protein coupled receptors, was used to generate a three-dimensional model of the hAT1 receptor based on bacteriorhodopsin. We observed a region within the model that was congruent with the biogenic amine binding site of beta 2, and were thus able to dock a model of the hAT1 antagonist L-158,282 (MK-996) into the transmembrane region of the receptor model. The antagonist was oriented within the helical domain by recognising that the essential acid functionality of this antagonist interacts with Lys199. The structural model is consistent with much of the information on structure-activity relationships for both non-peptide and peptide ligands.

CONCLUSIONS

Our model provides an explanation for the conversion of the antagonist L-158,282 (MK-996) to an agonist by the addition of an isobutyl group. It also suggests a model for domain motion during signal transduction. The approach of independently deriving three-dimensional receptor models and pharmacophore models of the ligands, then combining them, is a powerful technique which helps validate both models.