Chronic myocardial infarction is a substrate for bradycardia-induced spontaneous tachyarrhythmias and sudden death in conscious animals.

Introduction: Patients with bradycardia can have severe tachyarrhythmias but it is unclear whether bradycardia alone can induce arrhythmias or whether an additional substrate is necessary. While several animal models of ventricular tachycardia (VT) exist, no model has been reported to mimic the clinical condition of spontaneous VT and sudden cardiac death (SCD) in the presence of bradycardia and chronic myocardial infarction (MI) in large animals without manipulation of the autonomic nervous system. We tested the hypothesis that MI and bradycardia cause more spontaneous sustained VT than does bradycardia alone.

Metastatic colon cancer to the hand.

A 72-year-old male presented with a painful index finger 18 months after sigmoid colon resection for T2 N1 adenocarcinoma. A presumptive diagnosis of gout was made but directed therapy failed to alleviate symptoms. A bone scan was positive for the index finger only and plain films demonstrated a lytic lesion of the distal phalanx.

Outcome of 1000 liver cancer patients evaluated at the UPMC Liver Cancer Center.

We evaluated 1000 consecutive patients with liver tumors at the University of Pittsburgh Medical Center (UPMC) Liver Cancer Center over the 4-year period from August 2000 to August 2004. Of the 1000 patients seen, 573 had primary liver cancer and 427 had metastatic cancer to the liver. The mean age of the patients evaluated was 62.

Laparoscopic orchiectomy for unilateral intra-abdominal testis.

Purpose: A brief description of laparoscopic orchiectomy for undescended testis and a representative case report.

Methods: A 22-year-old Chinese man was admitted for removal of an intra-abdominal testis. Laparoscopic orchiectomy was used to remove the testis at the time of laparoscopic orchiectomy.

Pseudo-phosphorylation of tau at Ser202 and Thr205 affects tau filament formation.

The microtubule-associated protein tau aggregates into insoluble filaments in numerous neurodegenerative diseases, most common of which is Alzheimer's disease. Tau aggregation in Alzheimer's disease appears to follow a continuum from soluble monomer to an end point of insoluble extracellular tangles with a strong correlation between the amount of fibrillar tau and dementia. The phosphorylation of amino acids S202 and T205 in the tau molecule is recognized by the phosphorylation-specific monoclonal antibody, AT8, and has been observed by a number of researchers to be an early step in the progression of monomer to filaments.

Radio-frequency ablation of large, nonresectable hepatic tumors.

Patients with nonresectable hepatic metastases who are not treated survive an average of 6 months. We report our experience with radio-frequency ablation (RFA) of nonresectable hepatic tumors 4 cm or greater in size. A retrospective chart review of all patients undergoing RFA of hepatic tumors 4 cm or greater from October 1, 1999, through August 31, 2002, was performed.

Potential structure/function relationships of predicted secondary structural elements of tau.

The microtubule-associated protein tau is believed to be a natively unfolded molecule with virtually no secondary structure. However, this protein self-associates into filamentous forms in various neurodegenerative diseases. Since these filamentous forms show a remarkable degree of higher order due to their regular widths and periodicity, it is widely speculated that tau does contain secondary structures that come together to form tertiary and quaternary structures in the filamentous form.

The natural history of untreated penetrating diaphragm injury: an animal model.

Background: Surgical repair of diaphragm injuries is rather straightforward, but diagnosis can be difficult. The natural history of diaphragm injury is quite controversial. Undoubtedly, many diaphragmatic injuries are missed at the initial evaluation.

Bedside insertion of vena cava filters in the intensive care unit using intravascular ultrasound to locate renal veins.

Background: Historically, contrast venography has been used to determine renal vein location and assist with vena cava filter placement. This technique, however, exposes the patient to nephrotoxic contrast and radiation. For trauma patients in the intensive care unit (ICU), inferior vena cava filters should ideally be placed without contrast at the bedside to avoid nephrotoxic agents, radiation, and transport of a critically injured patient to the operating room or x-ray department.

Norepinephrine is a more potent inhibitor of tumor necrosis factor over a range of doses than dopamine.

In the current study, we test the hypothesis that norepinephrine has greater anti-inflammatory effects versus dopamine over a range of doses in a model of lipopolysaccharide (LPS)-stimulated cytokine release in human saphenous vein. Segments of saphenous vein were cut and separated into 1 mm x 1 mm squares and placed into two 24-well plates. These small segments of vessels were incubated in the presence of 20 microg/mL bacterial LPS, alone as a control or with 10x-6, 10x-5, 10x-4, 10x-3 concentration of dopamine or norepinephrine and LPS.

Clonogenic analysis reveals reserve stem cells in postnatal mammals. II. Pluripotent epiblastic-like stem cells.

Undifferentiated cells have been identified in the prenatal blastocyst, inner cell mass, and gonadal ridges of rodents and primates, including humans. After isolation these cells express molecular and immunological markers for embryonic cells, capabilities for extended self-renewal, and telomerase activity. When allowed to differentiate, embryonic stem cells express phenotypic markers for tissues of ectodermal, mesodermal, and endodermal origin.

Bowel obstruction caused by a Meckel's diverticulum enterolith: a case report and review of the literature.

Meckel's diverticulum is the most common congenital gastrointestinal anomaly. It may infrequently cause bleeding, perforation, or rarely obstruction. Formation of enteroliths in the diverticulum is uncommon.

Adult malrotation: a case report and review of the literature.

Midgut malrotation is an anomaly of fetal intestinal rotation that usually presents in the first month of life. It is rare for malrotation to present in adulthood. Symptomatic patients present either acutely with bowel obstruction and intestinal ischemia with a midgut or cecal volvulus, or chronically with vague abdominal pain.

Impact of a surgical oncologist on general surgery residency training program.

Background: To assess the impact of adding a surgical oncologist to our faculty we examined the operative experience in our program before and after the addition.

Methods: Operative case numbers reported to the American Board of Surgery over a 10-year period were analyzed. This time period encompassed 5 years before and after the addition of a surgical oncologist to our faculty.

Modeling tau polymerization in vitro: a review and synthesis.

The major antigenic component of neurofibrillary pathology in a large number of neurodegenerative diseases consists of the microtubule-associated protein tau. It is currently unclear how tau protein makes the transition from an important component of the microtubule-based cytoskeleton to an insoluble polymerized state. In vitro techniques have been employed to study the polymerization of tau in an effort to understand the underlying molecular mechanisms responsible for this process.

Caspase cleavage of tau: linking amyloid and neurofibrillary tangles in Alzheimer's disease.

The principal pathological features of Alzheimer's disease (AD) are extracellular amyloid plaques and intracellular neurofibrillary tangles, the latter composed of the microtubule-binding protein tau assembled into paired helical and straight filaments. Recent studies suggest that these pathological entities may be functionally linked, although the mechanisms by which amyloid deposition promotes pathological tau filament assembly are poorly understood. Here, we report that tau is proteolyzed by multiple caspases at a highly conserved aspartate residue (Asp421) in its C terminus in vitro and in neurons treated with amyloid-beta (Abeta) (1-42) peptide.

The L266V tau mutation is associated with frontotemporal dementia and Pick-like 3R and 4R tauopathy.

We report a case of rapidly progressive frontotemporal dementia presenting at age 33 years. At autopsy there was severe atrophy of the frontal and temporal lobes. Tau-positive Pick bodies, which ultrastructurally were composed of straight filaments, were present, accompanied by severe neuronal loss and gliosis.

Inhibition of tau polymerization by its carboxy-terminal caspase cleavage fragment.

Abnormal aggregation of the microtubule-associated protein, tau, occurs in many neurodegenerative diseases, making it important to understand the mechanisms of tau polymerization. Previous work has indicated that the C-terminal region of tau inhibits polymerization in vitro, and a growing body of evidence implicates caspase cleavage of tau at Asp 421 in the C-terminus as an important inducer of tau polymerization in Alzheimer's disease. In the present study, we provide evidence that the C-terminal peptide fragment produced by caspase cleavage inhibits tau polymerization, suggesting that caspase cleavage of tau enhances its polymerization by removing the inhibitory control element.

Ectopic thyroid.

Primary mediastinal ectopic goiters are very rare. We report a case in which an ectopic goiter with blood supply from the thoracic vessels necessitated a transternal approach for removal, resulting in a favorable outcome.

A prospective evaluation of a bedside technique for placement of inferior vena cava filters: accuracy and limitations of intravascular ultrasound.

Our objective was to evaluate the safety and accuracy of a bedside technique for placing vena cava filters with intravascular ultrasonography. We conducted a prospective case series of 36 patients requiring prophylactic vena cava filter placement. Intravascular ultrasound (IVUS) was used to assess the best location for inferior vena cava filter placement.