Factorial verbal and performance IQs derived from the WISC-R: their psychometric properties

A method is discussed for securing Factorial Verbal and Factorial Performance IQs from the WISC-R by means of an orthogonal rotation of the axes that describe the plane of the first two principal components derived from an analysis of the intercorrelations of the WISC-R subtests. The reliability and validity of these IQs also are described. Sex differences in normal children are found, as well as differences between normal and learning-disabled children.     

Increased prostacyclin and thromboxane A2 biosynthesis in atherosclerosis.

It has been proposed that atherosclerotic arteries produce less prostacyclin (PGI2) than nonatherosclerotic arteries do, thereby predisposing arteries to vasospasm and thrombosis in vivo. We reexamined this concept by measuring spontaneous as well as arachidonate-induced PGI2 biosynthesis in aortic segments from nonatherosclerotic and cholesterol-fed atherosclerotic New Zealand White rabbits. Thromboxane A2 (TXA2) generation was also measured. Formation of PGI2, as well as TXA2, as measured by radioimmunoassay (RIA) of their metabolites, was increased in atherosclerotic aortic segments relative to nonatherosclerotic segments (P less than or equal to 0.05) at 0, 5, 10, 15, and 30 min of incubation with arachidonate. Pretreatment of arterial segments with indomethacin inhibited PGI2 as well as TXA2 formation, whereas pretreatment with the selective TXA2 inhibitor OKY-046 inhibited only TXA2 release, thus confirming the identity of icosanoids. To confirm the RIA data, aortic segments were incubated with [14C]arachidonate prior to stimulation with unlabeled arachidonate. The uptake of arachidonate was similar, but the release of incorporated [14C]arachidonate was significantly (P less than or equal to 0.05) greater in atherosclerotic segments than in nonatherosclerotic ones. Conversions of released [14C]arachidonate to 6-keto[14C]prostaglandin F1 alpha and [14C]thromboxane B2 were similar in the two types of aortic segments. Thus, synthesis of PGI2 as well as TXA2 is increased in atherosclerosis, and this alteration in arachidonate metabolism is related to increased release of arachidonate.     

Color Doppler ultrasound imaging of lower-extremity venous disease

A color Doppler ultrasound imaging device was used to evaluate 475 patients with suspected lower-extremity venous thrombosis. Occlusive and nonocclusive femoral and popliteal thrombi were detected in 200 studies (42%). In phase 1 of the study (240 examinations), peripheral augmentation with the use of periodic calf compression was required to show color flow throughout the femoropopliteal venous segment. In phase 2 (235 examinations), with a software upgrade to enhance detectability of slow flow, spontaneous flow could be appreciated in the normal, partly thrombosed, and recanalized femoral popliteal veins without augmentation. Augmentation was often necessary to view tibioperoneal veins. Of the total study group, conventional venography was performed for correlation in 47 patients. In the other patients, clinicians relied on the color Doppler test for the definitive diagnosis of the presence or absence of femoral popliteal venous thrombosis and treated these patients on the basis of the color Doppler test result. In the femoral veins, color Doppler studies and venography agreed in all 12 positive and 35 negative cases. In the popliteal veins, there was agreement in five isolated popliteal thromboses and in 10 femoral popliteal thromboses; there were two false-negative color Doppler studies of isolated popliteal thromboses. In four patients, Doppler studies detected nonocclusive thrombus not evident on venography. Color Doppler imaging is easy to perform and does not require augmentation to view color flow in the femoropopliteal venous segment. Eccentric thrombus and partially canalized thrombus can be shown. Initial experience suggests color Doppler imaging may be useful in the detection of tibioperoneal venous thrombosis.     

The production and repair of DNA damage by N-nitrosobis(2-oxopropyl)amine and azaserine in hamster and rat pancreas acinar and duct cells

The activation of N-nitrosobis(2-oxopropyl)amine (BOP) by pancreasacinar and duct tissue from Syrian hamsters and MRC-Wistar ratsin vitro and in vivo was measured in terms of the productionand repair of DNA damage. Hamsters were given BOP (1 x 10 mg/kg,s.c.). DNA single strand breaks (SSB) were measured over 2 weeks.Significantly more SSB were present in duct than in acinar tissue.Their persistence in the duct fragments was due to a slowerrate of repair. In a related experiment, duct fragments wereisolated from BOP treated (1 x 10 mg/kg, s.c.) hamsters 24 hafter exposure and cultured for 6 days, or were isolated 7 daysafter exposure. The extent of DNA damage was comparable in thetwo groups, indicating that the repair process(es) were stilloperative in cultured cells. Isolated duct fragments were exposedto either BOP or N-nitrosomethyl(2-oxopropyl)amine (MOP) invitro. MOP produced significantly more DNA damage than BOP evenat a 5-fold lower dose. This is consistent with the greatercarcinogenicity of MOP in the pancreas. BOP produced significantlyless DNA damage in the rat pancreas than in the hamster pancreas.The rate of repair was at least twice as fast in the rat pancreasas in the hamster pancreas. There did not appear to be any preferencefor acinar or duct tissue in rats as there was lit hamsters.This procedure was validated in rats by the use of the rat pancreascarcinogen azaserine, which only produced DNA damage in ratacinar tissue.     

Down-regulation of an abundant cellular protein associated with tumor progression

Alteration of gene expression in neoplastic cells can be detectedby two-dimensional gel electrophoresis. This study reports thealtered synthesis of an abundant cellular protein, p29, accompanyingtumorigenic transformation of immortalized fibroblasts inducedby transfection with oncogenic DNA. Cell lines derived frommorphologically transformed foci synthesized p29 at 60–75%reduced levels compared with untransformed parental cells. Uponinoculation into syngeneic immunocompetent animals, transformedcells gave rise to tumors which were excised and establishedin culture. The amount of p29 in both focal and tumor-derivedlines was inversely correlated with the latent period for tumorformation. In cell lines with a tumor latency of 12–20days, the level of p29 was decreased by 90–99%. In rapidlytumorigenic cells with a short latency (3–6 days), p29synthesis was not detectable. These data demonstrate that p29may be a sensitive and reliable marker for tumor progressionof fibroblasts.     

Computed tomography examination of periampullary neoplasms

The hospital records of 24 patients with periampullary neoplasms were reviewed. The clinical triad of jaundice, pain, and weight loss and the radiographic imaging triad of dilated biliary ducts, dilated pancreatic duct, and periampullary mass should suggest the diagnosis of periampullary neoplasm.     

A growth factor in bovine and human testes structurally related to basic fibroblast growth factor

Homogenates of human testes, epididymides and prostate, and calf testes and epididymides are mitogenic for cultured human foreskin fibroblasts. The growth factors appear similar in that they are inactivated by boiling and acid, but not by treatment with reducing agent. The growth factor in human and bovine testes was partially purified from tissue homogenates, prepared in high ionic strength buffer (pH 7.6) containing protease inhibitors, by ammonium sulfate precipitation and two cycles of heparin-Sepharose chromatography. The growth factor in calf testes was also partially purified from tissue extracted in ammonium sulfate without protease inhibitors, acidified to pH 4.5, and precipitated by ammonium sulfate followed by two cycles of heparin-affinity chromatography. A predominant 17,500 molecular weight (MW) growth factor was identified from alkaline homogenates of human and calf testes by its reactivity with antisera prepared against synthetic peptides whose sequences corresponded to residues 1-12 (amino-terminal), 33-43 (internal) and 136-145 (carboxy-terminal) of bovine basic fibroblast growth factor (bFGF). A slightly smaller 16,600 MW peptide from acidic extracts of calf testes also reacted with antisera to the three synthetic peptides. A 15,500 MW peptide, lacking immunoreactivity with antiserum to the amino-terminal synthetic peptide, was also seen. These findings suggest that a growth factor is present in human and calf testes that is structurally related to bFGF. The structure of the growth factors appears to be altered during the isolation procedure.     

Compression of the right pulmonary artery by aortic aneurysms: CT demonstration

Two cases are presented in which compression of the right pulmonary artery by thoracic aortic aneurysm was demonstrated using dynamic CT. The patients initially presented with symptoms suggestive of pulmonary embolus and were found to have unilateral absence of perfusion on isotope lung scan. Computed tomography was useful in demonstrating pulmonary artery compression by aortic aneurysm as the cause in both cases, and in demonstrating an aortic dissection in one case.     

Urinary tract calculi and thresholds in carcinogenesis.

Numerous chemicals administered to rodents at relatively high doses produce urinary tract calculi, resulting in erosions or ulcerations of the urothelium, consequent regenerative hyperplasia, and ultimately tumors. This is a high-dose (threshold) phenomenon, which appears to occur more readily in rodents than in primates, including humans. Several anatomic and urinary physiologic differences between rodents and humans affect the quantitative extrapolation from results in rodent bioassays to human risk assessment. For most chemicals producing tumors by this mode of action, human exposures are significantly lower than would be expected to be required for production of calculi, and therefore pose no carcinogenic hazard to humans.