Biomedical subjects

Tushar R Patel

Publications and source records attributed to Tushar R Patel.

4 recordsLinked to original sources

PubMed2006

Staphylococcal liver abscess and acute cholecystitis in a patient with Crohn's disease receiving infliximab.

We present an unusual case of empyema of the gallbladder associated with a pyogenic liver abscess in a patient with Crohn's disease on Infliximab. It manifested by weakness, weight loss, and vague abdominal pain, which eventually localized to the right upper quadrant 4 days prior to admission. Diagnostic evaluation, which included ultrasonography and computed tomography, revealed cholelithiasis, gallbladder wall thickening, and a low-attenuation, complex mass in the left hepatic lobe. Cholecystectomy and open drainage of the liver abscess were successfully performed. There are few reports of intrahepatic abscess associated with Crohn's disease. The relationship between acute cholecystitis and Crohn's disease has also been documented. However, this report documents the unusual complication of pyogenic liver abscess secondary to acute cholecystitis in the unique population of Crohn's disease patients on Infliximab.

Adult↗

PubMed2004

Frontal bone periosteal osteomas.

Osteomas are the most common tumors of the cranial vault and facial skeleton. Osteomas are usually benign in nature, commonly presenting with symptoms of facial deformity, facial pain, and headaches. Although the frontal sinus is the most frequent location of cranial osteomas, they are also occasionally seen involving only the frontal bone periosteum. This study is a retrospective series investigating the characteristics, management, and outcomes of five patients with frontal bone periosteal osteomas surgically treated with superficial osteotomies with primary closure. Medical charts were reviewed focusing on symptoms, size, radiographic findings, and disease of the periosteal osteomas. The chief complaint primarily involved a palpable deformity, which led to surgical evaluation. Radiographic studies were obtained to evaluate size and location of the frontal osteomas. Microanalysis of the specimens confirmed the presence of mature cancellous and/or cortical bone. Postoperative follow-up revealed no evidence of recurrence or complications. The superficial ostectomy technique with primary closure offers a simple, effective method for removal of frontal bone periosteal osteomas with minimal side effects.

Adult↗

PubMed2004

Simvastatin suppresses LPS-induced Akt phosphorylation in the human monocyte cell line THP-1.

BACKGROUND: Activation of the small GTPase, Rac, requires post-translational modification by isoprenylation. Statins interfere with this process by blocking the synthesis of isoprenoid intermediates. The protein kinase Akt is a multifunctional regulator of cell behavior that has been linked to Rac activation. We have shown that lipopolysaccharide (LPS) stimulation leads to Rac activation in THP-1 cells. Therefore, we hypothesized that LPS stimulation would also activate Akt, a downstream effector of Rac, and that this may be blocked by statin pretreatment. MATERIALS AND METHODS: THP-1 cells were maintained in 1% fetal calf serum with or without 20 microM simvastatin for 24 h, followed by LPS stimulation for increasing time. Cytoskeletal changes were observed using Alexa-Phalloidin. Akt was immunoprecipitated from total cell lysate. Activated Akt was detected by immunoblotting with a phospho-Akt antibody and was quantified by image densitometry. RESULTS: LPS stimulation of THP-1 cells results in membrane ruffling and cell polarization. Furthermore, LPS increased Akt activation in THP-1 cells when compared with the nonstimulated controls. Akt phosphorylation peaked after 15 min of LPS stimulation and was suppressed by pretreatment with simvastatin. CONCLUSIONS: These data demonstrate that LPS stimulation leads to increased Akt phosphorylation, which can be suppressed with simvastatin pretreatment. This suggests one possible mechanism through which simvastatin could modulate LPS-induced signaling events in monocytes to improve the host response to Gram-negative infections.

Actins↗

PubMed2003

Mevastatin suppresses lipopolysaccharide-induced Rac activation in the human monocyte cell line THP-1.

BACKGROUND: Rac is a member of the Rho family of small guanosine triphosphatases that regulate the actin cytoskeleton. Activation of Rac requires lipid modification that can be blocked by statins. Lipopolysaccharide-induced rearrangements in the actin cytoskeleton lead to changes in cell adhesion and motility that play a role in the cellular response to infection. The lipid products of phosphatidylinositol-3 kinase (PI3K) modulate Rac effector pathways and have been linked to the activation of the Rac-guanosine triphosphatase. We hypothesize that lipopolysaccharide stimulation leads to Rac activation and that this may be inhibited by statin pretreatment. Furthermore, signaling downstream of Rac is linked to PI3K; therefore, we hypothesize that a signaling complex between PI3K and Rac may be involved. METHODS: THP-1 cells were maintained in 1% fetal calf serum with or without 20 micromol/L mevastatin for 24 hours, followed by lipopolysaccharide stimulation. Active Rac was precipitated from THP-1 total cell lysate and then detected by immunoblotting. The PI3K-Rac complex was immunoprecipitated from total cell lysate, and the p85 regulatory subunit of PI3K was detected by immunoblotting. RESULTS: Lipopolysaccharide stimulation activated Rac. Rac activation was suppressed by pretreatment with mevastatin. The p85 subunit of PI3K was associated with Rac. CONCLUSIONS: Lipopolysaccharide stimulation leads to Rac activation in THP-1 cells, which may be suppressed with mevastatin pretreatment. There is an association between Rac and PI3K that demonstrates a role for PI3K in the activation of downstream Rac effector pathways.

Cell Line↗