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Biomedical subjects

L Rosen

Publications and source records attributed to L Rosen.

232 records · Page 13Linked to original sources
PubMedDate not supplied

Contrast and electrolyte dynamics of the intravenous pyelogram. II. Disparities in serum and urine concentrations of meglumine and anion.

Intravenous or intra-aortic injections of meglumine iothalamate in dogs indicate a slightly different tissue distribution and excretory pattern of the meglumine cation and the iothalamate anion. Differences in serum and urinary concentrations of these ions suggest some cellular penetration of the meglumine anion. In addition, there seems to be some evidence for both tubular absorption and tubular excretion of meglumine as a minor component in the renal excretion of this ion. No significant differences could be demonstrated for either urinary load or concentration when the sodium salts of iothalamate were compared to the methylglucamine salts.

Animals↗
PubMedDate not supplied

Velocity of left ventricular wall motion determined by fluoroscopic videodensitometry. A noninvasive method for evaluating myocardial contractile state.

Videodensitometry of the margins of the fluoroscopic image of the left ventricle (LV) was used to evaluate LV wall motion and differentiation of the wall motion signal reflected velocity of LV contraction (dV/dt) during various inotropic interventions in six anesthetized dogs. During these interventions heart rate, afterload and preload were maintained constant. Alterations in dV/dt were similar to changes in simultaneously measured LV peak dP/dt and the quotient of dP/dt and developed LV pressure, two widely accepted parameters of LV contractile state. Wide variations in preload and afterload caused no significant changes in dV/dt. Thus, the current study indicates that fluoroscopic videodensitometry provides a specific and reliable noninvasive method for evaluating LV contractile state.

Absorptiometry, Photon↗
PubMedDate not supplied

Why does kidney size change during I.V. urography?

Meglumine iothalamate (280 ml I/ml) and sodium iothalamate (400 mg I/ml) in doses of 700 mg I/kg bw, were injected i.v. as a bolus in dogs. Renal size, urine flow rate, arterial pressure, renal blood flow and mean transit time and renal blood volume were measured before and after injection. All changes were qualitatively and quantitatively identical for both drugs. They produced a small transient renal shrinkage followed by a greater and prolonged renal enlargement. During the period of renal enlargement, urine flow increased. The time course of the enlargement paralleled the increase of urine flow rate. Renal blood flow also increased but both the mean transit time and renal vascular volume decreased. Therefore, the kidney size increase after i.v. injection of large doses of urographic contrast media cannot be attributed to an increased volume of the vessels. Most likely it is caused by diuresis-induced increase in the volume of the tubules.

Animals↗
PubMedDate not supplied

Arterial blood flow measurement: assessment of velocity estimation methods.

Three methods are presented which provide statistically acceptable estimates of mean transit time of opacified blood during angiography. While the methods vary in precision, the selection of the method appropriate for any particular experimental model depends on the degree of precision required to demonstrate the effect under investigation. As the day follows the night, the cost of equipment increases with increasing precision and the inexpensive method may provide sufficient accuracy for most clinical situations.

Angiography↗
PubMedDate not supplied

[Transovarial transmission of arboviruses by mosquitoes (author's transl)].

An important aspect of the epidemiology of arboviruses is the manner in which the viruses are maintained during winter, dry season, or other adverse environmental periods when their arthropod hosts are inactive. One possibility is that the viruses survive in arthropods. In the case of mosquito-borne viruses, it is probable that such viruses could be maintained in this manner only if they were transmitted from one insect generation to the next by transovarial transmission. Such transmission was reported in 1905 by Marchoux and Simond for yellow fever virus in Aedes aegypti. Other workers were unable to confirm this observation and, until very recently, it was believed to be in error. Interest in transovarial transmission of viruses by mosquitoes was reawakened with the recovery of La Crosse virus from field-collected larvae of Aedes triseriatus in 1972. Among bunyaviruses, transovarial transmission has been observed mainly among the California serogroup viruses in Aedes mosquitoes. Among flaviviruses, transovarial transmission has been demonstrated experimentally for the viruses of principal interest to man, namely, yellow fever, dengue, japanese encephalitis, and St-Louis encephalitis. Thus far, the only field evidence of transovarial transmission of flaviviruses is the isolation of yellow fever virus from Aedes furcifei/taylori males captured in nature in 1977. At present there is not conclusive evidence that transovarial transmission of alphaviruses occurs in mosquitoes. Among rhabdoviruses, transovarial transmission of vesicular stomatitis virus has been demonstrated experimentally at a relatively high rate in phlebotominae flies. Many factors are known to affect the experimental transovarial transmission of viruses. The significance of such transmission in nature can only be assessed by field studies.

Alphavirus↗
PubMedDate not supplied

Deletion of genetic material from a poly(ADP-ribose) polymerase-like gene on chromosome 13 occurs frequently in patients with monoclonal gammopathies.

Recently, by using a probe for the nuclear DNA repair enzyme poly(ADP-ribose) polymerase gene, a pseudogene was found on the long arm of chromosome 13. RFLP analysis demonstrates the presence of a common "A" allele and a rare "B" allele, which has a deletion of approximately 200 bp. This deletion occurs more frequently in blacks than in whites in the United States. In two B-cell malignancies, Burkitt's and follicular lymphomas, there is a marked increased frequency of the expression of the B allele. Thus, we have analyzed the frequency of this allele in another B-cell malignancy, multiple myeloma (MM), which is also more frequently observed in blacks. We studied 97 patients with MM (41 black and 56 white patients) and 30 patients with the related disorder monoclonal gammopathy of undetermined significance (MGUS; 13 black and 17 white patients). The results demonstrate that the overall frequency of B allele expression (37%) is higher than in a noncancer control population (23%; P < 0.01). This difference is mainly due to the much higher frequency of B expression in black patients (52 versus 35% in black controls; P < 0.01), whereas there is no significant difference in white patients (18 versus 14% in white controls). Overall, B allelic frequency is similar in patients with MM and MGUS. Matched germline and tumor DNA show identical patterns of expression of these alleles. These results suggest germline B allelic expression predisposes one to MM and MGUS.

Alleles↗