Distribution of TAS2R38 bitter taste receptor phenotype and haplotypes among COVID-19 patients.

Bitter taste receptor TAS2R38 is expressed in the respiratory tract and can respond to quorum-sensing molecules produced by pathogens, stimulating the release of nitric oxide, with biocidal activity. TAS2R38 presents two main high-frequency haplotypes: the "taster" PAV and the "non-taster" AVI. Individuals carrying the AVI allele could be at greater risk of infections, including SARS-CoV-2. The aim of this study was to assess the frequency of PAV and AVI alleles in COVID-19 patients with severe or non-severe symptoms compared to healthy subjects to further corroborate, or not, the hypothesis that the PAV allele may act as a protecting factor towards SARS-CoV-2 infection while the AVI one may represent a risk factor. After careful selection, 54 individuals were included in the study and underwent genetic analysis and PROP phenotype assessment. Our investigation could not point out at a significant relationship between single nucleotide polymorphisms responsible for PROP bitterness and presence/severity of SARS-CoV-2 infection, as previous studies suggested. Our results uncouple the direct genetic contribution of rs10246939, rs1726866 and rs713598 on COVID-19, calling for caution when proposing a treatment based on TAS2R38 phenotypes.

Modulation of bleomycin-induced lung fibrosis by serotonin receptor antagonists in mice.

Serotonin (5-hydroxytryptamine; 5-HT) is known to increase proliferation and collagen synthesis by fibroblasts. Two receptor subtypes, 5-HT2A and 5-HT2B, have been shown to play the most important roles in the lung. In the present study, the role of serotonin in lung fibrosis was investigated using the bleomycin mouse model. Serotonin concentrations in lung homogenates increased significantly over the time course of bleomycin-induced fibrosis, with a maximum at day seven. The expression of serotonin receptors 5-HT2A and 5-HT2B increased in the lung after bleomycin treatment, as assessed by PCR, specific binding and immunohistochemistry. Blockage of 5-HT2A receptors by ketanserin and 5-HT2B receptors by SB215505 reduced bleomycin-induced lung fibrosis, as demonstrated by reduced lung collagen content and reduced procollagen 1 and procollagen 3 mRNA expression. Serotonin antagonists promoted an antifibrotic environment by decreasing the lung mRNA levels of transforming growth factor-beta1, connective growth factor and plasminogen activator inhibitor-1 mRNA, but had minimal effects on lung inflammation as assessed by bronchoalveolar lavage cytology analysis. Interestingly, the 5-HT2B receptor was strongly expressed by fibroblasts in the fibroblastic foci in human idiopathic pulmonary fibrosis samples. In conclusion, the present study showed involvement of serotonin in the pathophysiology of bleomycin-induced lung fibrosis in mice and identified it as a potential therapeutic target in lung fibrotic disorders.

Vasorelaxation induced by prostaglandin E2 in human pulmonary vein: role of the EP4 receptor subtype.

BACKGROUND AND PURPOSE: PGE2 has been shown to induce relaxations in precontracted human pulmonary venous preparations, while in pulmonary arteries this response was not observed. We investigated and characterized the prostanoid receptors which are activated by PGE2 in the human pulmonary veins. EXPERIMENTAL APPROACH: Human pulmonary arteries and veins were cut as rings and set up in organ baths in presence of a TP antagonist. A pharmacological study was performed using selective EP1-4 ligands. The cellular localization of the EP4 receptors by immunohistochemistry and their corresponding transcripts were also investigated in these vessels. KEY RESULTS: PGE2 and the EP4 agonists (L-902688, ONO-AE1-329) induced potent vasodilatation of the human pulmonary vein, pEC50 values: <7.22+/-0.20, 8.06+/-0.12 and 7.80+/-0.09, respectively. These relaxations were inhibited by the EP(4) antagonist GW627368X and not modified in presence of the DP antagonist L-877499. Higher concentrations (>or=1 microM) of the EP2 agonist ONO-AE1-259 induced relaxations of the veins. The EP4 agonists had no effect on the precontracted arteries. Finally, the EP(1) antagonists ONO-8713 and SC-51322 potentiated the relaxation of the veins induced by PGE2. EP4 and EP1 receptors were detected by immunohistochemistry in the veins but not in the arteries. EP4 mRNA accumulation was also greater in the veins when compared with the arterial preparations. CONCLUSIONS AND IMPLICATIONS: Of the 4 EP receptor subtypes, smooth muscle cells in the human pulmonary vein express the EP4 and EP1 receptor subtypes. The relaxations induced by PGE2 in this vessel result from the activation of the EP4 receptor.

PML nuclear bodies are general targets for inflammation and cell proliferation.

Acute promyelocytic leukemia is associated with a t(15;17) translocation that generates a fusion product between PML and the retinoic acid receptor alpha. Recently, PML was shown to concentrate within subnuclear domains, referred to as nuclear bodies, that are disorganized in acute promyelocytic leukemia cells. This observation provided the first evidence that alteration of a nuclear structure may play a role in human pathogenesis. In an attempt to clarify the role of PML and, more generally, of the associated nuclear bodies, we used immunohistochemistry to explore the expression of PML in normal, inflammatory, and neoplastic human tissues. With the exception of endothelial cells and macrophages that contain a high amount of PML protein, a weak speckled labeling pattern was observed in the nucleus of all cell types analyzed. By contrast to normal tissues, the level of PML expression was considerably enhanced in inflammatory tissues, predominantly around the mononuclear cell infiltrate, as well as during either normal or pathological proliferative states, in particular in tumoral pathology. Surprisingly, in most hepatocellular carcinoma, a cytoplasmic delocalization of PML was observed. Finally, the number of PML nuclear bodies increased up to twice their normal value as quiescent cultured cells were stimulated to grow upon serum addition. Altogether these results strongly suggest that the PML-associated nuclear bodies are implicated both in the inflammatory process and in cell growth control.

Differential expression of matrix metalloproteinases after stent implantation and balloon angioplasty in the hypercholesterolemic rabbit.

BACKGROUND: Intimal hyperplasia is the principal mechanism of in-stent restenosis. Matrix metalloproteinases (MMPs) play a key role in intimal growth after balloon angioplasty (BA). Little is known, however, about MMP expression after stent implantation (ST). We investigated whether MMP9 and MMP2 are differentially expressed after ST and BA. METHODS AND RESULTS: Hypercholesterolemic rabbits underwent ST and BA in the right and left iliac arteries, respectively. The expression of MMPs and their inhibitors (TIMPs) was studied at various time points in the injured arteries by use of zymography, reverse transcription-polymerase chain reaction, and immunohistochemistry. MMP2, but not MMP9, was constitutively expressed in uninjured arteries. MMP9 expression was rapidly induced after injury, whereas the increase in MMP2 expression was delayed. At all time points, pro-MMP9 activity and MMP9 mRNA levels were >/=2-fold (ANOVA, P=0.002) and >/=3-fold (P<0.0001) higher after ST than after BA, respectively. Active MMP9 was detected only after ST. Although the increases in MMP2 mRNA levels were of similar magnitudes after ST and BA, pro-MMP2 activity was slightly higher 7 and 30 days after ST, and MMP2 activity was >/=2-fold higher 7 to 60 days after ST (P=0.002). No difference in TIMP expression was observed between stented and balloon-injured arteries. Cellular distributions of MMPs and TIMP1 were similar after ST and BA. Early inflammatory cell recruitment and 30-day intimal growth were more severe after ST. CONCLUSIONS: Stent implantation results in more intense and sustained expression of MMP9 and activation of MMP2 than balloon angioplasty.

Human immunodeficiency virus (HIV) leukoencephalopathy and the microcirculation.

We studied the brains of three patients with acquired immune deficiency syndrome (AIDS), all of whom developed subacutely progressive dementia unassociated with opportunistic infection or neoplasm in the central nervous system. Computed tomographic (CT) scans of the head revealed cortical atrophy, ventricular dilation, and diffuse hypodensity of the centrum semiovale. On microscopic examination, the cerebral and cerebellar white matter in all cases showed diffuse and focal, angiocentric regions of myelin pallor, focal vacuolization, and extensive gliosis. Variable axonal loss and axonal spheroids were evident. The microvasculature showed striking changes, including mural thickening, increased cellularity, and enlargement and pleomorphism of endothelial cells with variable numbers of macrophages and multinucleated giant cells (MNGC), which often contained hemosiderin pigment. Human immunodeficiency virus type 1 (HIV-1) antigens were identified immunocytochemically within perivascular macrophages and MNGC and in some microglial cells. We suggest that the morphologic abnormalities of the microcirculation may be associated with an alteration of the blood-brain barrier. The increased vascular permeability could contribute to damage and loss of the white matter including both myelin and axons, and result in subcortical cerebral atrophy. The HIV-1 infected cells present in relation to the microvasculature may play a role in mediating the vascular injury.

Delayed white matter injury in a murine model of shaken baby syndrome.

Shaken baby syndrome, a rotational acceleration injury, is most common between 3 and 6 months of age and causes death in about 10 to 40% of cases and permanent neurological abnormalities in survivors. We developed a mouse model of shaken baby syndrome to investigate the pathophysiological mechanisms underlying the brain damage. Eight-day-old mouse pups were shaken for 15 seconds on a rotating shaker. Animals were sacrificed at different ages after shaking and brains were processed for histology. In 31-day-old pups, mortality was 27%, and 75% of survivors had focal brain lesions consisting of hemorrhagic or cystic lesions of the periventricular white matter, corpus callosum, and brainstem and cerebellar white matter. Hemorrhagic lesions were evident from postnatal day 13, and cysts developed gradually between days 15 and 31. All shaken animals, with or without focal lesions, had thinning of the hemispheric white matter, which was significant on day 31 but not earlier. Fragmented DNA labeling revealed a significant increase in cell death in the periventricular white matter, on days 9 and 13. White matter damage was reduced by pre-treatment with the NMDA receptor antagonist MK-801. This study showed that shaking immature mice produced white matter injury mimicking several aspects of human shaken baby syndrome and provided evidence that excess release of glutamate plays a role in the pathophysiology of the lesions.

Cranial pachymeningitis of unknown origin: a study of seven cases.

We report seven patients with cranial pachymeningitis of unknown origin in whom the main clinical features were headaches, ataxia, and cranial nerve palsies. CSF showed inflammatory changes. CT and MRI showed thickening of the falx and of the tentorium. The clinical course was chronic. Four patients improved with prednisolone but became steroid-dependent: in two cases, radiotherapy had no lasting improvement and in one, azathioprine permitted a reduction of the corticosteroids. Five patients had biopsy of the tentorium cerebelli or of the temporal dura mater. In two cases, autopsy revealed extensive pachymeningitis without parenchymal changes. In all instances, microscopic examination of the dura mater showed a cellular infiltrate of polymorphic cells; there were no epithelioid granulomas. Review of the literature discloses seven similar cases. We discuss the relationship of these lesions with inflammatory meningeal masses, the focal pachymeningitis of the Tolosa-Hunt syndrome, and multifocal fibrosis.

Dissecting aneurysm of the vertebral artery and cervical manipulation: a case report with autopsy.

A 35-year-old woman with 3 weeks of cervical pain developed ischemia in the basilar artery territory following cervical manipulation. At autopsy, there was a dissecting aneurysm within the third segment of the right vertebral artery. The pathologic changes in the lower and the upper part of the dissecting aneurysm were different, indicating recurring bleeding. Cervical manipulation could have accounted for one recent dissection, but not for another, which was a few weeks old. This suggests that cervical pain, which prompted the manipulation, may have been the first symptom of the dissection, and manipulation of the neck precipitated the stroke by inducing bleeding within the dissecting aneurysm.

Severe encephalitis resulting from coinfections with HIV and JC virus.

We observed 3 cases of progressive multifocal leukoencephalopathy (PML) among frozen CNS samples obtained at autopsy from 102 adult AIDS patients. In 2 patients, PML was associated with severe HIV encephalitis. In those 2 cases, the areas of extensive JC-induced demyelination were massively infiltrated by HIV infected macrophages/microglial cells with evidence for localized increase of HIV encephalitis in PML lesions. Using immunohistochemistry and in situ hybridization, we demonstrated that each virus infects, in a latent or productive fashion, different CNS cell populations. Therefore, the extension of HIV encephalitis could not be related to an intracellular transactivation of 1 virus by the other. However, the results are consistent with dissemination of viral infection by the recruitment of HIV-infected macrophages to damaged areas of the brain. This phenomenon might be generalized to other pathogens that are frequently associated with HIV CNS infection. Early detection and treatment of opportunistic CNS lesions could be important to prevent extension of HIV encephalitis.

Detection and localization by in situ molecular biology techniques and immunohistochemistry of hepatitis C virus in livers of chronically infected patients.

Hepatitis C virus (HCV) detection in the livers of chronically infected patients remains a debatable issue. We used immunohistochemistry, in situ hybridization (ISH) alone or after microwave heating with FITC-labeled probes, RT-PCR with unlabeled primers followed by ISH (RT-PCR-ISH), and in situ RT-PCR with FITC-labeled primers (in situ RT-PCRd) to localize the virus in 38 liver biopsy specimens from 21 chronically infected HCV patients treated with interferon-alpha (IFN-alpha). Biopsies were taken at the beginning and end of IFN-alpha treatment and 1 year later. Results were compared with that of HCV-PCR in serum. RT-PCR-ISH and in situ RT-PCRd showed HCV signal in all liver biopsies even in responders with seronegative HCV PCR. This signal was intranuclear, diffuse, or peripheral, in hepatocytes, bile ductule cells, and lymphocytes. Cytoplasmic signals were occasionally observed. Whereas the percentage of labeled hepatocytes remained constant, the number of labeled lymphoid follicles decreased after INF-alpha therapy. Immunohistochemistry resulted in the same pattern of positivity but it was weaker and inconstant. This study indicates the persistency of HCV latency in IFN-alpha responders 1 year after IFN-alpha treatment cessation, a finding that certainly deserves confirmation.

Neuropathology of the spinal cord in the acquired immunodeficiency syndrome.

The neuropathologic findings in the spinal cord were reviewed in 138 consecutive autopsies of patients with the acquired immunodeficiency syndrome. In all cases both the brain and spinal cord were examined by conventional histologic techniques, and in 63 cases immunohistochemistry was used to detect human immunodeficiency virus (HIV), Toxoplasma gondii, cytomegalovirus, and JC papovavirus antigens. The most common observation was a normal spinal cord (60%). Vacuolar myelopathy (VM) was observed in 23 (17%) cases. Human immunodeficiency virus myelitis was evident in 8% of cases. Human immunodeficiency virus myelitis was associated with HIV encephalitis in 65% of the cases. Opportunistic infections of the spinal cord were uncommon, consisting of cryptococcosis (five cases), cytomegalovirus (four cases), toxoplasmosis (one case), and progressive multifocal leukoencephalopathy (one case), and almost always were seen with cerebral and/or systemic infection by these agents. Malignant lymphoma rarely involved the spinal cord (four cases); all were B-cell lymphomas and were associated with cerebral and/or systemic lymphoma. Other abnormalities rarely observed were Wallerian degeneration of the corticospinal tracts or posterior columns (6%) and focal microinfarcts. Most cases of VM (78%) were not associated with HIV myelitis, and in the five patients with both VM and HIV myelitis, HIV-infected cells were not found in the regions affected by VM. In contrast, 65% of cases with VM were associated with HIV encephalitis. The pathogenesis of VM remains unknown; it is probably not due to direct infection by HIV.

Report of a fatal case of dengue infection with hepatitis: demonstration of dengue antigens in hepatocytes and liver apoptosis.

A fatal case of dengue (DEN) infection associated with a spleen rupture and with hepatitis is reported here. Microscopic studies showed numerous areas of spleen rupture with hematomas and revealed necrotic foci in liver samples obtained at autopsy. Although hepatitis was reported in several cases of DEN fever, the mechanism of liver injury remains poorly understood. In this case, immunohistochemistry showed that DEN viral antigens were mostly detected in hepatocytes surrounding the necrotic foci. By in situ detection of DNA fragmentation, apoptotic hepatocytes were found to be colocated with DEN virus-infected hepatocytes. These findings suggest that hepatocytes are the major sites of DEN virus replication in the liver and that DEN virus induces apoptosis of hepatocytes in vivo.

Primary central nervous system lymphomas in 72 immunocompetent patients: pathologic findings and clinical correlations. Groupe Ouest Est d'étude des Leucénies et Autres Maladies du Sang (GOELAMS)

We reviewed 72 primary central nervous system lymphomas occurring in immunocompetent patients. The cases were reviewed for clinical data, histology, immunophenotype, bcl-2 and p53 expression, and Epstein-Barr virus association. Follow-up was available for 40 patients included in the Groupe Ouest Est d'étude des Leucénies et Autres Maladies du Sang (GOELAMS) lymphomes cérébraux primitifs (LCP 88) trial. Each diagnosis, requiring a consensus among at least 3 pathologists, was performed according to the recent Revised European-American Lymphoma classification and equivalents in the updated Kiel classification. Tumors were predominantly classified as diffuse large B-cell lymphomas. There were 3 T-cell lymphomas and 1 Hodgkin lymphoma. The proteins bcl-2 and p53 were expressed in 35% and 16% of the tested cases, respectively. Epstein-Barr virus was not found by in situ hybridization except in the case classfied as a cerebral localization of Hodgkin disease. No significant association was found between subtypes, bcl-2 or p53 expression, and patient survival. From the standpoint of their biologic characteristics, primary central nervous system lymphomas are very similar to systemic diffuse large B-cell lymphomas. In contrast to AIDS-related primary central nervous system lymphomas, primary central nervous system lymphomas are rarely associated with Epstein-Barr virus and in immunocompetent patients they express bcl-2 at a relatively low rate.

Overexpression of p53 protein in Barrett's syndrome with malignant transformation.

AIMS: To study the overexpression of p53 protein in Barrett's oesophagus with adenocarcinoma, and to correlate this expression with the pathological features of Barrett's syndrome. METHODS: Immunohistochemical staining was performed on frozen sections with a monoclonal antibody directed against wild type and mutated p53 protein (Pab 1801). Eleven cases of Barrett's adenocarcinoma were studied, seven of which had extensive sampling of benign Barrett's mucosa. RESULTS: Eight of 11 adenocarcinomas overexpressed the p53 protein. Both early and advanced tumours were positive. In Barrett's mucosa around the p53 positive tumours, high grade dysplasia was positive; low grade dysplasia and non-dysplastic mucosa were negative. CONCLUSIONS: P53 gene mutation with ensuing p53 protein overexpression is a common feature of Barrett's adenocarcinoma, both at early and advanced stages. This mutation appears as a relatively late event during the neoplastic transformation of Barrett's oesophagus.

Expression of c-erbB-2 oncogene product in Barrett's adenocarcinoma: pathological and prognostic correlations.

AIMS: To establish the prevalence of c-erbB-2 protein expression in a surgical series of Barrett's adenocarcinomas; and to correlate this expression with clinicopathological data and prognosis. METHODS: Sixty six surgical specimens of Barrett's adenocarcinomas were included in this retrospective study. Blocks of the tumour and of non-dysplastic Barrett's mucosa were stained with a polyclonal antibody specific for the intracytoplasmic domain of the c-erbB-2 protein. RESULTS: Seven of 66 tumours showed membrane staining for the c-erbB-2 protein. The non-dysplastic Barrett's mucosa was negative in all cases. There was no difference between c-erbB-2 positive and negative tumours with regard to mean age, sex ratio, percentage of alcohol misusers, percentage of smokers, tumour differentiation, depth of invasion, lymph node response, and proliferative activity, assessed by the percentage of tumour cells positive with the MIB-1 antibody directed against the Ki-67 antigen. All c-erb B2 positive tumours were of Lauren's intestinal type compared with negative c-erbB-2 tumours. Patients with c-erbB-2 positive tumours had a significantly poorer prognosis than patients with negative tumours. CONCLUSIONS: The prevalence of Barrett's adenocarcinomas expressing c-erbB-2 found in this study (11%) was similar to that observed in published series of gastric adenocarcinomas. c-erbB-2 protein expression could be an important prognostic indicator in Barrett's adenocarcinoma.

Lymphoma-induced polyradiculopathy in AIDS: two cases.

Progressive polyradiculopathy is a rare, well-documented complication of the acquired immunodeficiency syndrome in man. It has been commonly attributed to a cytomegalovirus (CMV) infection. We report two HIV-infected patients with clinical and electrophysiological features of a unique, subacute, progressive polyradiculopathy. Post-mortem examination in case 1 disclosed an infiltration of the leptomeninges, the lumbar spinal cord, and the anterior and posterior roots by a B-cell immunoblastic lymphoma. Immunochemistry for HIV1 and CMV was negative in the peripheral and the central nervous system. Case 2 showed bone-marrow involvement by a Burkitt type lymphoma. Specific chemotherapy was followed by both clinical improvement of the polyradiculopathy and complete remission on a second bone-marrow biopsy. These findings may indicate that a lymphoma must also be considered a possible cause of polyradiculopathy in AIDS.

p53 protein expression and DNA ploidy in cystic tumors of the pancreas.

Cystic tumors of the pancreas form a heterogeneous group, with benign, premalignant, and malignant tumors. The molecular events that underlie their neoplastic transformation process are poorly understood. Our purpose was to study DNA ploidy by flow cytometry and p53 protein expression by immunohistochemistry in a large series of cystic tumors of the pancreas. The series of 51 surgical specimens included 18 serous cystadenomas, 20 mucinous cystic tumors (benign, n = 14; borderline, n = 1; malignant, n = 5), 10 intraductal papillary-mucinous tumors (benign, n = 4; borderline, n = 1; malignant, n = 5), and 3 papillary and cystic tumors. The p53 protein immunohistochemical study was done in all cases on deparaffinized sections stained with the monoclonal antibody DO7. DNA flow cytometry was performed in 31 cases on formalin-fixed and paraffinembedded material. Neither p53 protein immunoreactivity nor DNA aneuploidy was observed in any case of serous cystadenoma. p53 protein overexpression was present in four of five malignant mucinous cystic tumors but was absent in benign and borderline cases. Only one case of malignant mucinous cystic tumor was DNA aneuploid. All benign and borderline intraductal papillary-mucinous tumors were p53 negative, and two of five malignant cases were p53 positive. There was no DNA aneuploidy in any case of intraductal papillary-mucinous tumors. The three cases of papillary-cystic tumors showed neither p53 protein immunoreactivity nor DNA aneuploidy. In cystic tumors of the pancreas, p53 protein overexpression and DNA aneuploidy are rare events, restricted to malignant cases, mostly mucinous cystadenocarcinomas. Our results confirm that this group of tumors is heterogeneous and underline the need for earlier markers of an aggressive behavior.

Age-related changes of neuronal counts in the human pedunculopontine nucleus.

Cholinergic neurons in the basal forebrain and the upper brainstem undergo changes during aging and in dementia of the Alzheimer type, Parkinson's disease and progressive supranuclear palsy. Little is known about the effect of age on neurons in the tegmental pedunculopontine nucleus. Cholinergic neurons revealed by choline acetyltransferase immunohistochemistry were quantified in the brains of 20 subjects who died without neurological disorder between 28 and 101 years of age. A U-shaped relationship between cell counts and age was found, namely, a decrease in counts between 28 and 70, a minimum between 80 and 91 years of age, and, in four subjects aged 98-101 years counts comparable to those of subjects having died between 28 and 65 years. The findings suggest that the loss of cholinergic pedunculopontine nucleus neurons is not linear. In centenarians age-related neuronal decrease in pedunculopontine nucleus neurons may be slower or the stock of pedunculopontine nucleus neurons greater than in subjects dying earlier.

Expression of insulin-like growth factor-I in rat glioma cells is associated with change in both immunogenicity and apoptosis.

Insulin-like growth factor I (IGF-I), has a role in cellular differentiation and is also expressed in neoplastic transformation of glioma cells. We recently demonstrated inhibition in expression of cellular IGF-I after transfection with vectors that incodes a segment of the human IGF-I RNA in antisense orientation. The transfected cells expressed increased levels of both MHC-I and B7 molecules. In this paper we show that IGF-I antisense transfected cells also become apoptotic. Moreover, the phenomenon of programmed cell death is related to the phenomenon that results in increased expression of MHC-I and B7 molecules. Co-transfection of rat glioma cells with the vector expressing IGF-I antisense RNA and with vectors encoding the expression of MHC-I and B7 antisense cDNA suppressed the expression of both of these molecules and was associated with a decrease in apoptosis.