Leiomyomatosis-like lymphangioleiomyomatosis: A case report of the colonic manifestation of tuberous sclerosis

Introduction:Tuberous sclerosis complex is an inherited multisystemic disorder with manifestations in various organ systems as a result of a mutation of 1 of 2 tumor suppressor genes, tuberous sclerosis complex-1 or tuberous sclerosis complex-2. Perivascular epithelioid cell tumors have been shown to be associated with these gene mutations and include a variety of tumors such as angiomyolipomas and lymphangioleiomyomatosis.Patient concerns:In this report, we present a case of a 28-year-old woman presenting with symptoms of severe abdominal pain and nausea with a medical history of cardiac rhabdomyoma, adenoma sebaceum, Ash leaf spots, bilateral renal angiomyolipomas, and retinal hamartoma, which are manifestations of tuberous sclerosis complex. The patient was operated twice for colonic perforations in the rectosigmoid and ileocecal regions where the pathologic examination revealed multiple tumoral lesions in both specimens.Diagnosis:The tumor consisted of a myomatous component where the nodules were composed of spindle cells with fascicular array, and a lymphangiomatous component where epithelioid cells could be observed. Immunohistochemically, smooth muscle markers (desmin and SMA) were positive and the epithelioid component showed HMB-45 positivity. A diagnosis of leiomyomatosis-like lymphangioleiomyomatosis was established due to its morphological and immunohistochemical features, the presence of the tumor in multiple foci, and widespread lymphovascular invasion.Interventions:The patient had a perforation in her bowel twice during the hospital stay and underwent Hartmann operation and ileocecal resection in 2 different surgical operations.Outcomes:After the second operation the patient developed fever and was diagnosed with SARS-CoV-2 infection. No other complication was observed during her stay and the patient''s follow-up was unremarkable.Conclusion:Perivascular epithelioid cell tumors are associated with tuberous sclerosis and can rarely appear in the colon. Therefore, lymphangioleiomyomatosis should be in the differential diagnosis in a tuberous sclerosis patient presenting with a colonic tumor.     

Co-expression of cyclooxygenase-2 and vascular endothelial growth factor in inflamed human pulp: an immunohistochemical study

Recent data from the medical literature indicates that cyclooxygenase-2 (COX-2) plays a key role in the production of vascular endothelial growth factor (VEGF), a glycoprotein that has the ability to increase the permeability of blood vessels and to induce angiogenesis. This study was undertaken to investigate the immunohistological co-expression of COX-2 and VEGF in inflamed human pulp, in conjunction with the expression of CD34, a transmembrane glycoprotein expressed in endothelial cells. Pulp tissue of extracted carious human third molars with a recent history of spontaneous pain were collected and processed for immunostaining of COX-2, VEGF, and CD34 using the biotin-streptoavidin method. Healthy pulp samples served as controls. COX-2 expression was not observed in healthy pulps, whereas all inflamed pulps demonstrated COX-2-expressing cells. Similarly, VEGF was not expressed in normal pulp tissue, but was strongly positive in inflamed pulps. CD34 was expressed in the endothelium of both normal and inflamed pulp tissues. Co-expression of COX-2 and VEGF in all consecutive sections of inflamed pulps could be suggestive of a possible release of VEGF via a COX-2-dependent pathway.     

Influence of additional reinforcement of fixed long-term temporary restorations on fracture load

Purpose

In implant dentistry, temporary restorations (TR) might often be required for up to one year. The aim of this in vitro study was to evaluate the long-time performance of four-unit TRs in the posterior region based on different materials and reinforcement methods.

Ureterovesical junction obstruction causes increment in smooth muscle contractility,and cholinergic and adrenergic activity in distal ureter of rabbits

Background/Purpose

The controversy in management of primary obstructed megaureter necessitates further elucidation of the underlying pathophysiology. We evaluated smooth muscle contractility, and cholinergic, adrenergic and serotonergic activity of rabbit distal ureters after ureterovesical junction (UVJ) obstruction.

Methods

Sham (SH) operation, partial obstruction (PO) and complete obstruction (CO) of the right UVJ were performed in rabbits. Three weeks later, distal ureters were isolated; spontaneous contractions (SC), contractile responses to electrical field stimulation (EFS), high KCl, carbachol, phenylephrine and serotonin were recorded.

Results

SC amplitudes increased in CO compared to PO and SH (p < 0.001). SC frequency was higher in CO (p < 0.05). EFS-induced contraction amplitudes were greater in CO than other groups (p < 0.05). High KCl-induced contractions were greater in CO (p < 0.001) and PO (p < 0.01). Carbachol-induced contractility was enhanced in CO and PO (p < 0.05). Contractile response to phenylephrine was greater in CO than other groups (p < 0.05). Serotonin induced contractile responses in CO and PO, greater in CO (p < 0.05). UVJ obstruction also increased spontaneous contractility in contralateral PO and CO ureters.

Conclusions

UVJ obstruction increased spontaneous and neurotransmitter-induced contractions in an obstruction grade-dependent manner. Obstruction also altered contractility of the contralateral ureters. Our findings may serve to provide further understanding of the pathophysiology of megaureter.     

AMP-activated protein kinase connects cellular energy metabolism to KATP channel function

AMPK is an important sensor of cellular energy levels. The aim of these studies was to investigate whether cardiac K(ATP) channels, which couple cellular energy metabolism to membrane excitability, are regulated by AMPK activity. We investigated effects of AMPK on rat ventricular K(ATP) channels using electrophysiological and biochemical approaches. Whole-cell K(ATP) channel current was activated by metabolic inhibition; this occurred more rapidly in the presence of AICAR (an AMPK activator). AICAR had no effects on K(ATP) channel activity recorded in the inside-out patch clamp configuration, but ZMP (the intracellular intermediate of AICAR) strongly activated K(ATP) channels. An AMPK-mediated effect is demonstrated by the finding that ZMP had no effect on K(ATP) channels in the presence of Compound C (an AMPK inhibitor). Recombinant AMPK activated Kir6.2/SUR2A channels in a manner that was dependent on the AMP concentration, whereas heat-inactivated AMPK was without effect. Using mass-spectrometry and co-immunoprecipitation approaches, we demonstrate that the AMPK α-subunit physically associates with K(ATP) channel subunits. Our data demonstrate that the cardiac K(ATP) channel function is directly regulated by AMPK activation. During metabolic stress, a small change in cellular AMP that activates AMPK can be a potential trigger for K(ATP) channel opening. This article is part of a Special Issue entitled "Local Signaling in Myocytes".