Renovascular hypertension as a complication of umbilical arterial catheterization

Renovascular hypertension (RVH) in the neonatal period is frequently associated with thromboembolic complications of umbilical artery catheterization. Seven newborn infants with RVH were studied by angiography and/or radionuclide examination. Aortography and, in one case, selective angiography showed variable degrees of renal artery occlusion or attenuation. Thromboembolic defects were frequently present in other vessels. Radionuclide flow studies, renograms, and computer analysis of data (ADAC) demonstrated defects in renal function, indicative of renal ischemia. There was a high degree of correlation between angiographic and radionuclide studies. Successful medical management suggests a more conservative alternative to nephrectomy in the hypertensive newborn.     

The treatment of advanced stage favorable histology non-Hodgkin's lymphoma: a preliminary report of a randomized trial comparing single agent chemotherapy, combination chemotherapy, and whole body irradiation

Between 1975 and 1978, 51 patients with favorable histology non- Hodgkin's lymphomas, pathologic stage III-IV, were treated prospectively on a randomized treatment protocol. Treatment options were single alkylating agent chemotherapy, combination chemotherapy with cyclophosphamide, vincristine, and prednisone (CVP), or fractionated whole body irradiation followed by low dose involved field irradiation. The median follow-up interval in this group of patients is not 41 mo. Actuarial survival is excellent, 84% at 4 yr for the entire group, with similar survival observed for each of the three treatment options. Initial complete remission rates (64%, 88%, and 71%) were not significantly different in the three treatment arms. Frequent relapse after initial remission induction was noted, however, with a freedom from relapse at 4 yr of only 25%. The toxicities of the three therapies were acceptable. Acute complications of therapy were most numerous in the group of patients treated with CVP; however, long-term hematologic depression was most commonly observed in patients treated with whole body irradiation. In general, hematologic complications were more frequent among patients who had marrow involvement and intact spleens at the time of initial therapy. The relationship of this study to other clinical trials in the management of patients with advanced stage favorable histology lymphomas and its implications for future clinical trials are discussed.     

Quantitation of human in vitro megakaryocytopoiesis by radioimmunoassay

The isolation and characterization of human megakaryocyte growth factors has been hampered because evaluation of megakaryocyte growth in semisolid medium requires both lengthy incubation and visual quantitation. In addition, colony formation requires cell division, while most regulation of platelet production may involve individual, nonproliferating differentiating megakaryocytes. We have developed a radioimmunoassay (RIA) that makes use of an iodinated murine monoclonal antibody (MoAb) specific for platelet/megakaryocyte glycoprotein IIb/IIIa (GPIIb/IIIa) to measure megakaryocyte production in liquid marrow culture. This assay is sensitive to 3 X 10(3) platelets (roughly 30 megakaryocytes) and linear up to 1 X 10(6) platelets, and thus it provides a useful range for quantitating megakaryocyte production in in vitro marrow culture. Significant differences (threefold to fivefold) in megakaryocyte/platelet-specific GPIIb/IIIa complex are detected between stimulated and unstimulated marrow cultures by day 7, although antigen accrual in stimulated cultures continues through at least day 16. Conditions that promote megakaryocyte growth in semisolid medium (ie, aplastic plasma and PHA-LCM) have also been facilitory in liquid culture. This rapid and sensitive assay for cell-bound GPIIb/IIIa should facilitate recognition and isolation of megakaryocyte and platelet growth factors.     

Measurement precision and biological variation of cranial arteries using automated analysis of 3 T magnetic resonance angiography

Background

Non-invasive magnetic resonance angiography (MRA) has facilitated repeated measurements of human cranial arteries in several headache and migraine studies. To ensure comparability across studies the same automated analysis software has been used, but the intra- and interobserver, day-to-day and side-to-side variations have not yet been published. We hypothesised that the observer related, side-to-side, and day-to-day variations would be less than 10%.

Methods

Ten female participants were studied using high-resolution MRA on two study days separated by at least one week. Using the automated LKEB-MRA vessel wall analysis software arterial circumferences were measured by blinded observers. Each artery was analysed twice by each of the two different observers. The primary endpoints were to determine the intraclass correlation coefficient (ICC) and intra- an inter-observer, the day-to-day, and side-to-side variations of the circumference of the middle meningeal (MMA) and middle cerebral (MCA) arteries.

Results

We found an excellent intra- and interobserver agreement for the MMA (ICC: 0.909-0.987) and for the MCA (ICC: 0.876-0.949). The coefficient of variance within observers was ≤1.8% for MMA and ≤3.1% for MCA; between observers ≤3.4% (MMA) and ≤4.1% (MCA); between days ≤6.0% (MMA) and ≤8.0% (MCA); between sides ≤9.4% (MMA) and ≤6.5% (MCA).

Conclusion

The present study demonstrates a low (<5%) inter- and intraobserver variation using the automated LKEB-MRA vessel wall analysis software. Furthermore, the study also suggests that the day-to-day and side-to-side variations of the MMA and MCA circumferences are less than 10%.     

Incidence and mortality of acute and chronic pancreatitis in the Netherlands:A nationwide record-linked cohort study for the years 1995-2005

AIM:To analyze trends in incidence and mortality of acute pancreatitis(AP) and chronic pancreatitis(CP) in the Netherlands and for international standard populations.METHODS:A nationwide cohort is identified through record linkage of hospital data for AP and CP,accumulated from three nationwide Dutch registries:the hospital discharge register,the population register,and the death certificate register.Sex-and age-group specific incidence rates of AP and CP are defined for the period 2000-2005 and mortality rates of AP and CP for the period 1995-2005.Additionally,incidence and mortality rates over time are reported for Dutch and international(European and World Health Organization) standard populations.RESULTS:Incidence of AP per 100000 persons per year increased between 2000 and 2005 from 13.2(95%CI:12.6-13.8) to 14.7(95%CI:14.1-15.3).Incidence of AP for males increased from 13.8(95%CI:12.9-14.7) to 15.2(95%CI:14.3-16.1),for females from 12.7(95%CI:11.9-13.5) to 14.2(95%CI:13.4-15.1).Irregular patterns over time emerged for CP.Overall mean incidence per 100000 persons per year was 1.77,for males 2.16,and for females 1.4.Mortality for AP fluctuated during 1995-2005 between 6.9 and 11.7 per million persons per year and was almost similar for males and females.Concerning CP,mortality for males fluctuated between 1.1(95%CI:0.6-2.3) and 4.0(95%CI:2.8-5.8),for females between 0.7(95%CI:0.3-1.6) and 2.0(95%CI:1.2-3.2).Incidence and mortality of AP and CP increased markedly with age.Standardized rates were lowest for World Health Organization standard population.CONCLUSION:Incidence of AP steadily increased while incidence of CP fluctuated.Mortality for both AP and CP remained fairly stable.Patient burden and health care costs probably will increase because of an ageing Dutch population.     

Kringle glycosylation in a modified human tissue plasminogen activator improves functional properties

Native tissue plasminogen activator (ntPA) has a variable glycosylation site on its kringle-2 domain. We have examined the effects of kringle glycosylation on functional properties by studying the simplified tPA molecule, tPA-6. tPA-6 is composed of kringle-2 and the serine protease domains and, like ntPA, cells expressing tPA-6 process it into two glycoforms: the monoglycosylated tPA-6-primary (tPA-6P, type II) with N- linked glycosylation at Asn-448 in the serine protease domain and diglycosylated tPA-6-variant (tPA-6V, type I) with glycosylation at Asn- 448 and at Asn-184 in kringle-2. When the two glycoforms were separated, we found that purified tPA-6V had reduced fibrin-stimulated plasminogenolytic activity toward Glu-plasminogen when compared to purified tPA-6P. However, in the presence of fibrin, tPA-6V unexpectedly exhibited a sixfold increase in selectivity toward Lys- plasminogen. In addition, tPA-6V was less susceptible than tPA-6P to plasmin-mediated conversion to the two-chain form. By site-directed mutagenesis of tPA-6, we eliminated variable glycosylation at Asn-184 and engineered a new glycosylation signal at a remnant site in the kringle. This derivative, designated tPA-6D, was secreted with complete kringle glycosylation. Like the naturally occurring tPA-6V, tPA-6D had lower rates of fibrin-stimulated Glu-plasminogen activation, increased specificity toward Lys-plasminogen, and greater resistance to plasmin digestion. Although the activity of tPA-6D could be stimulated by fibrin, its activity was not stimulated significantly by fibrinogen, and in human plasma the rate of fibrinogen depletion was reduced threefold. Although fibrin binding to kringle-2 of tPA-6D was slightly improved, there was a substantial increase in the dissociation constant (kd) for lysine binding, demonstrating a lack of correlation between these ligand-binding sites. Overall, our data demonstrate the marked effect of kringle glycosylation on functional properties. In addition, we have generated a derivative with properties that potentially improve clot specificity and single-chain half-life and reduce the potential for plasminogen activation in the plasma.