Screening for deep venous thrombosis in asymptomatic postoperative orthopedic patients using color Doppler sonography: analysis of prevalence and risk factors.

OBJECTIVE: The purpose of our study was to assess the prevalence and risk factors for sonographically detectable lower extremity deep venous thrombosis (DVT) in asymptomatic patients following major orthopedic surgery. SUBJECTS AND METHODS: We performed color Doppler sonography of the lower extremities in 474 asymptomatic patients following major hip or knee surgery. We determined the prevalence of lower extremity DVT and used stepwise logistic regression to identify factors predictive of DVT. All patients received routine prophylactic measures. RESULTS: The prevalence of DVT was 7%. Laterality of surgery, age, and gender were all independent predictors of DVT (p < or = .01): the odds of having DVT were 20 times higher in the leg that was operated upon than in the leg that was not; the odds of DVT rose by a factor of 1.5 per decade of life; and the odds of DVT were 3.4 times greater in men than in women. DVT was more common in patients who had received general rather than epidural anesthesia, with borderline significance (p = .06). The length of anesthesia and the joint involved (hip or knee) were not predictive of DVT (p > .10). CONCLUSION: Despite prophylaxis, DVT is a relatively common postoperative complication in patients who undergo major orthopedic procedures. Routine screening for DVT is warranted in asymptomatic patients who have undergone hip or knee surgery, and color Doppler sonography, despite its limitations, offers a reasonably accurate noninvasive method for screening these patients. Subsets of patients who are at particular risk include the elderly, male patients, and patients who have undergone general anesthesia. The low prevalence of DVT in limbs not operated upon suggests that routine screening may be limited to evaluating the affected limbs only, thus helping to minimize the cost of screening.

Lymphoma and leukemia involving the testicles: findings on gray-scale and color Doppler sonography.

OBJECTIVE: The purpose of this study was to determine the gray-scale and color Doppler sonographic appearance of testicular lymphoma and leukemia to aid in its differentiation from primary testicular neoplasms and inflammatory processes. MATERIALS AND METHODS: We retrospectively reviewed the testicular sonograms of eight male patients 5-74 years old (mean age, 43 years) with pathologically proved testicular leukemia or lymphoma. All patients presented with testicular enlargement. Gray-scale sonograms were obtained to determine the presence or absence of a mass, focal nodule, or diffuse infiltration, as well as the degree of parenchymal echogenicity. Color Doppler sonography was applied in each case to determine the degree of vascularity compared with normal ipsilateral or contralateral testicular parenchyma. In patients with focal, measurable lesions, the size was correlated with its color Doppler sonographic appearance. RESULTS: Gray-scale sonograms showed either homogeneously hypoechoic testes in patients with diffuse round-cell infiltration or multifocal hypoechoic lesions of various sizes. Five patients had a total of 11 focal lesions that ranged in size from 8 mm to 26 mm in maximum diameter (mean diameter, 16 mm). Color Doppler sonography revealed increased intralesional flow in all areas of lymphomatous or leukemic involvement irrespective of lesion size. CONCLUSION: Our results show that testicular lymphoma and leukemia are hypervascular on color Doppler sonograms regardless of the size of the tumor. Although color Doppler sonography may provide useful information, differentiating round-cell infiltration from inflammatory processes of the testes remains difficult.

Sequence and functional differences between Schmidt-Ruppin D and Schmidt-Ruppin A strains of pp60v-src.

We show that Schmidt-Ruppin D pp60v-src kinase activity is reduced by a mutation previously shown to be associated with Schmidt-Ruppin A pp60v-src temperature sensitivity and that its reduced transforming activity is associated with a conformational change in the SH3 region. The evolutionary relationship of seven v-src strains was studied by using parsimony analysis.

Gastric inhibitory polypeptide mechanisms of augmenting insulin secretion.

The cellular mechanisms whereby gastric inhibitory polypeptide (GIP) augments glucose-dependent insulin secretion remains poorly defined. Since glucose-dependent insulin secretion is modulated by membrane associated phospholipase A2 (PLA2) and intracellular lipoxygenase (LPX) and cyclooxygenase (CO) we hypothesize that GIP's augmentation of insulin secretion involves these enzyme systems. Neonatal rat pancreatic islet cell cultures were preincubated with 5.6mM glucose for 60 minutes. The cultures were then stimulated for 60 minutes with 16mM glucose alone or with GIP with or without the addition of PLA2, LPX, and CO inhibitors. Insulin secretion significantly increased (P less than 0.05) when the glucose concentration was raised from 5.6 to 16mM glucose and this was further augmented by the addition of GIP (P less than 0.05). PLA2 inhibitors significantly (P less than 0.025) decreased 16mM glucose insulin secretion but this was restored by the simultaneous addition of GIP. LPX inhibitors significantly (P less than 0.01) decreased glucose-dependent insulin secretion and this decrease persisted despite the addition of GIP. Simultaneous treatment of islet cell cultures with GIP and CO inhibitors yielded insulin responses that were indistinguishable from CO inhibition alone. These studies suggest that GIP exerts its influence in part by modulating membrane associated PLA2 activity. Furthermore, the formation of intracellular LPX products appears to be a pivotal step in the insulinotrophic action of GIP.