Walter L. Pipkin

Localization, Macromolecular Associations, and Function of the Small Heat Shock–Related Protein HSP20 in Rat Heart

Background—The small heat shock proteins HSP20, HSP25, &agr;B-crystallin, and myotonic dystrophy kinase binding protein (MKBP) may regulate dynamic changes in the cytoskeleton. For example, the phosphorylation of HSP20 has been associated with relaxation of vascular smooth muscle. This study examined the function of HSP20 in heart muscle. Methods and Results—Western blotting identified immunoreactive HSP20, &agr;B-crystallin, and MKBP in rat heart homogenates. Subcellular fractionation demonstrated that HSP20, &agr;B-crystallin, and MKBP were predominantly in cytosolic fractions. Chromatography with molecular sieving columns revealed that HSP20 and &agr;B-crystallin were associated in an aggregate of ≈200 kDa, and &agr;B-crystallin coimmunoprecipitated with HSP20. Immunofluorescence microscopy demonstrated that the pattern of HSP20, &agr;B-crystallin, and actin staining was predominantly in transverse bands. Treatment with sodium nitroprusside led to increases in the phosphorylation of HSP20, as determined with 2-dimensional immunoblots. Incubation of transiently permeabilized myocytes with phosphopeptide analogues of HSP20 led to an increase in the rate of shortening. The increased shortening rate was associated with an increase in the rate of lengthening and a more rapid decay of the calcium transient. Conclusions—HSP20 is associated with &agr;B-crystallin, possibly at the level of the actin sarcomere. Phosphorylated HSP20 increases myocyte shortening rate through increases in calcium uptake and more rapid lengthening.

Use of a virtual reality car-driving stressor in cardiovascular reactivity research

Eighteen subjects (11 males, 7 females) completed a virtual reality car-driving stressor on two occasions several weeks apart. Immediately before and throughout task performance, blood pressure, cardiac output, and total peripheral resistance were assessed. Reactivity scores were calculated for each parameter for each subject as the arithmetic difference between task level and baseline level. The task elicited considerable hemodynamic activation on each occasion of testing, as well as high levels of self-reported task realism, engagement, excitement, and nervousness. Correlation analyses of both absolute and reactivity scores revealed evidence of test-retest reliability. Males were found to exhibit greater absolute levels of and greater increases in systolic blood pressure. The development of tasks suitable for inclusion in a battery of behavioral stressors, responses to which may help identify those at risk for later disease, is of considerable interest in cardiovascular behavioral medicine. The present findings suggest that the virtual reality car-driving task may be useful in this context.

Fatigue as impairment or educational necessity? Insights into surgical culture.

Background The authors examine fatigue culture among surgical residents and faculty members and whether it squares with recent, fatigue-focused Accreditation Council for Graduate Medical Education (ACGME) policies and educational initiatives. Method Field observations of an academic general surgery program were supplemented with interviews (52 residents and 58 faculty members) conducted as part of a study of 15 general surgery programs. Field notes and interviews were analyzed for main themes. Results Most believe that fatigue surfaces after 24 hours of work and has minor consequences. Surgeons believe that residents can learn to manage fatigue and that surgical practice requires that capacity. Proper training implies that residents experience fatigue, learn to perform capably and confidently while fatigued, and recognize their limits. Conclusions Encountering and learning to manage fatigue are seen as educational necessities by surgeons, a view that runs counter to ACGME initiatives, requires reconsideration, and demands that attention be directed to professional and organizational practices that sustain fatigue culture.

Popliteal pseudoaneurysm caused by Nora's lesion of the femur in a young child: A rare presentation and first report

Bizarre parosteal osteochondromatous proliferation (BPOP), or Noras lesion, was first described by Nora et al. in 1983 as a rare, tumor-like lesion involving the bones of the hands and feet. Popliteal artery pseudoaneursyms in the pediatric population are also unusual. Here, we present a case of a young male with a popliteal artery pseudoaneurysm and distal femur lesion originally thought to be an osteochondroma. A 10-year old, Caucasian male was referred to our facility following an MRI concerning for a popliteal artery pseudoaneurysm. On physical exam, there was a palpable 5 × 5-cm pulsatile mass in the upper popliteal fossa with a normal pulse exam bilaterally. A computed tomographic angiogram demonstrated a 4.5-cm by 1.8-cm by 3.6-cm pseudoaneurysm adherent to a 3.5-cm thick, exostotic lesion of the posterior right femur. He was taken to the operating room for repair of the popliteal pseudoaneurysm and resection of his bone lesion. The final pathology was consistent with a popliteal pseudoaneurysm, osteochondroma, and bizarre parosteal osteochondromatous proliferation (BPOP), otherwise known as Noras lesion. The location of the lesion and the age of our patient were both atypical for BPOP and to our knowledge, this represents the first report of a resulting popliteal artery pseudoaneurysm.

Heterotopic gastric mucosa of the upper esophagus following repair of esophageal atresia with tracheoesophageal fistula

A term female newborn underwent uncomplicated repair of esophageal atresia with tracheoesophageal fistula (type C) then coarctation of the aorta. Subsequently, she developed symptomatic esophageal strictures, which required serial dilations. In addition, she suffered feeding intolerance from esophageal dysmotility and gastroesophageal reflux disease, necessitating Nissen fundoplication with gastrostomy. At 6 years of age, surveillance esophagogastroduodenoscopy revealed mild stenosis and heterotopic gastric mucosa of the upper esophagus at the level of the anastomosis. This is the second report of heterotopic gastric mucosa of the upper esophagus at the level of the anastomosis following repair of esophageal atresia with tracheoesophageal fistula.

Müllerian-type, cutaneous ciliated cyst in the gluteal cleft mimicking a pilonidal cyst.

Abstract A cutaneous ciliated cyst is a rare entity found predominantly in the lower extremities and perineal region of young females. Although initially described by Hess in 1890, the present day term, “cutaneous ciliated cyst,” was proposed by Farmer in 1978 and includes a wide array of cyst types. Despite their typical female predominance and location, many have described cutaneous ciliated cysts in males and atypical locations. In addition, Mullerian cysts in the posterior mediastinum and the retroperitoneum have been reported. To date, only 40 cases have been reported in the literature of a Mullerian-type, cutaneous ciliated cyst. Here, we report a case of 13-year-old female with one in the gluteal cleft, initially presenting as a pilonidal cyst. We also discuss the differential diagnosis of pediatric sacrococcygeal lesions and pathogenesis of a Mullerian-type, cutaneous ciliated cyst.

Gastroschisis associated with an omphalocele and intestinal atresia

An omphalocele and gastroschisis represent two common pediatric congenital abdominal wall defects, but are rarely associated with each other. An omphalocele results from an incomplete closure of the lateral body folds leading to a midline defect in the anterior abdominal wall. This manifests as herniated intra-abdominal contents into a membrane-covered sac, made up of an inner peritoneal and outer amniotic layer [1, 2]. With an incidence of 1 in 3,000 births, an omphalocele has a higher prevalence in males and is associated with chromosomal abnormalities in up to 40 % of patients [2]. On the other hand, a gastroschisis is a congenital abdominal wall defect that typically occurs to the right of the umbilicus and may be separated by a skin bridge [3]. The incidence is 0.3–1 per 10,000 births with associated anomalies present in up to 10 % of cases [3, 4]. Distal atresias, with a normal incidence of 1 in 1,500–5,000 births, represent one such anomaly with the ileum most commonly affected. We present a case with all three congenital anomalies, a finding we believe has never been reported. Case report

Laparoscopic Treatment of Simultaneously Occurring Pyloric Stenosis and Malrotation

Hypertrophic pyloric stenosis (HPS) is a common cause of nonbilious vomiting in the neonatal period with an incidence of approximately 1 to 3 per 1000 live births. The Ramstedt pyloromyotomy has been the standard treatment since 1912. In 1991, Alain et al. reported a novel approach to HPS using laparoscopy. Since this original description, the laparoscopic pyloromyotomy has become progressively more popular and, in many institutions, has replaced the open approach. Similarly, malrotation is a condition affecting the neonatal population, resulting from incomplete intestinal rotation about the superior mesenteric artery during weeks 10 through 11 of development. If left untreated, it can lead to abnormal mesenteric attachments and a narrowed mesenteric base, placing the patient at risk for midgut volvulus. The standard surgical treatment has been the open Ladd procedure first described in 1932. In 1996, Gross described a minimally invasive procedure to address malrotation. The association of concurrent pyloric stenosis and malrotation has rarely been reported in the pediatric literature. This is the first published report of a laparoscopic treatment of HPS and malrotation simultaneously.