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Biomedical subjects

R Weil

Publications and source records attributed to R Weil.

At least 55 records · Page 3Linked to original sources

Polyoma-induced stimulation of cellular RNA synthesis is paralleled by changed expression of the viral genome.

We studied synthesis of viral and cellular RNA in the presence and absence of 5-fluorodeoxyuridine (FdU, an inhibitor of DNA synthesis) during lytic infection with polyoma virus in confluent, primary mouse kidney cell cultures. In the presence of FdU, synthesis of early 19S polyoma mRNA and of polyoma tumor (T)-antigen, i.e. expression of the early viral gene, is rapidly followed by a mitogenic reaction of the host cell; it leads to an increase of 30 +/- 5% in cellular, mainly 28S and 18S rRNA, followed by activation of the cellular DNA-synthesizing apparatus. Polyoma-induced cellular RNA synthesis is paralleled by increased production of early 19S mRNA and begin of expression of the late viral genes, leading to synthesis of small amounts of late 19S and 16S mRNAs. Changed expression of the viral genome occurs in the absence of detectable synthesis of polyoma DNA I. Infection in the absence of FdU induces the same sequence of events; it is followed, however, by duplication of the mouse cell chromatin (S-phase) and production of progeny virus.

Cell Line

Urine plasmin-like substances as an index of kidney allograft rejections.

Using solid state radioimmunoassays developed by the first author, changes in the urine level of plasmin-like substances (PLS) and fibrin degradation products (FDP) before and after human kidney transplantation were determined in 49 transplant patients. Averages of urine PLS and FDP in a normal population of 51 persons were 0.13+/-0.10 (SD) and 0.14+/-0.07 microng/ml, respectively. In all transplant patients there was an initial rise of both PLS and FDP in urine immediately after transplantation. This elevation peaked on days 4 and 5 and the PLS and FDP levels returned to normal range within 2 weeks in patients without evidence of rejeciton. A secondary rise of urine PLS was detected before or with a rise in serum creatinine in all of the patients experiencing rejections. Of 11 patients who showed a rejection episode within 2 weeks of transplantation, the secondary rise of urine PLS was detectable in 55% of the patients slightly before the serum creatinine level changes; of 6 patients with a rejection episode more than 2 weeks after transplantation, 100% showed a secondary PLS rise 6.7+/-2.3 (SE) days before the serum creatinine increased. The appearance of the secondary rise of urine FDP in the rejecting recipients was slightly later than the rise of PLS. Serial determination of urine PLS levels following human kidney transplantation appears to be an early index of rejections which occurs more than 2 weeks after transplantation, although the clinical usefulness of this measurement is probably limited.

Creatinine

Canine and human liver preservation for 6 to 18 hr by cold infusion.

Forty-one dog livers were preserved with cold, lactated Ringer's, plasma, or intracellular (Collins) solutions. Consistent survival was obtained with all three solutions for 9 hr. After 18 hr, the plasma and Collins solutions permitted survival, with the Collins solution having a slight overall advantage. The method using Collins solution has been used to preserve seven human livers in Los Angeles, to transport the organs to Denver, and to transport them as orthotopic grafts from 6 hr, 45 min to 10 hr later.

Adult

Liver transplantation of Budd-Chiari syndrome.

Orthotopic liver transplantation was accomplished in a 22-year-old woman dying of the Budd-Chiari syndrome. She is well and has normal liver function 16 months postoperatively. In view of the good early result, it will be appropriate to consider liver replacement for this disease in further well-selected cases.

Adult

The effect of renal hydrodynamics on immune complex deposition.

The role of renal hydrodynamics on renal deposition of immune complexes was evaluated in acute serum sickness. Using i.v. radiolabelled antigen in rabbits under a variety of hydrodynamic alterations, these studies suggested that although intrarenal hydrodynamics influence renal deposition of immune complexes factors other than intrarenal hydrostatic pressure may be important.

Animals

Successful transplantation of ectopic kidneys from living related donors.

Two ectopic pelvic kidneys were transplanted from living donors into well matched recipients. Both kidneys have good function at two and four years post transplantation and there has been no evidence of infection post transplantation. Such kidneys can be utilized when there is no evidence of obstruction or infection in the donor and when the contralateral kidney is normal.

Adult

Energy-dependent binding of dansylgalactoside to the lac carrier protein: direct binding measurements.

High specific activity 6'-N-[3H]dansyl)aminohexyl 1-thio-beta-D-galactopyranoside (Dns6-Gal) has been synthesized, and its binding to Escherichia coli membrane vesicles measured directly by flow dialysis. With ML 308-225 vesicles containing the lac carrier protein, specific binding is not detected in the absence of D-lactate or reduced phenazine methosulfate. In the presence of these electron donors, binding is observed, and the binding constant and number of binding sites are approximately 4 muM and 1.5 nmol/mg of membrane protein, respectively. These values are in excellent agreement with those obtained by fluorescence titration. p-Chloromercuribenzenesulfonate, which directly inactivates the lac carrier protein, and carbonylcyanide m-chlorophenylhydrazone, which collapses the membrane potential, cause release of bound Dns6-Gal. Moreover, significant binding is not observed with membrane vesicles that are devoid of the lac carrier protein. The results provide qualitative and quantitative confirmation of previous studies which indicate that changes in dansylgalactoside fluorescence observed on "energization" of membrane vesicles reflect binding of the probe to the lac carrier protein.

4-Chloromercuribenzenesulfonate

Two forms of simian-virus-40-specific T-antigen in abortive and lytic infection.

Simian-virus-40-specific T-antigen was isolated by immunoprecipitation. From other studies we have proof that the T-antigen described in this work is coded by the viral DNA. The molecular weight estimated from electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels of T-antigen isolated from nonpermissive mouse cells in abortive infection is 86,000 and from permissive monkey cells in lytic infection is 82,000. The 86 kilodalton T-antigen is readily converted in vitro into an 82 kilodalton form by incubation with extracts from permissive monkey cells but not with extracts from nonpermissive mouse or hamster cells. This and the results of fingerprinting analysis of tryptic peptides suggest that T-antigen may be processed in permissive cells.

Animals

Mapping of the three species of polyoma mRNA.

The polyoma mRNA's present in the cytoplasm of primary cultures of mouse kidney cells during lytic infection were characterized by sedimentation velocity analysis and by hybridization to polyoma DNA fragments generated by a specific endonuclease of Hemophilus parainfluenzae (Hpa II).

Base Sequence

Isolation and characterization of poly(A)-containing intranuclear polyoma-specific "giant" RNA'S.

Heterogeneous polyoma giant RNA molecules have been isolated by oligo(dT)- cellulose chromatography during the late phase of a lytic cycle of infection of mouse kidney cell cultures. These RNAs have sedimentation coefficients in denaturing Me2SO gradients that are greater than 26S and thus apparently correspond to RNA molecules larger than one strand of polyoma DNA. Approximately 15% of total nuclear polyoma late giant RNAs contained tracts of poly(A) and were retained by oligo(dT)-cellulose. The polyoma late giant RNAs as well as heterogeneous nuclear RNAs (HnRNAs) were found to have a slightly lower sedimentation rate in Me2SO-chloral hydrate density gradients than sedimentation values in sucrose gradients indicated. Even when synthesis of viral DNA and the production of capsid protein are blocked by 5-fluorodeoxyuridine (FdU), 10% of polyoma-specific RNA (as determined by sedimentation analyses under aqueous conditions) was shown to contain tracts of poly(A). In contrast to our findings on polyoma late giant RNA, nuclear polyoma RNA synthesized in the presence of FdU sedimented in denaturing Me2SO-chloral hydrate gradients considerably slower (from 15 to 30S) in relation to HnRNA and ribosomal precursor RNA. The sedimentation pattern in denaturing Me2SO gradients suggest that Py RNA synthesized late in lytic infection in the presence of FdU may be no longer than one transcript of Py DNA.

Cell Line

Pancreatic islet isografts, allografts, and xenografts: comparison of morphology and function.

Neonatal rat pancreatic islets were transplanted intraperitoneally into adult streptozotocin-diabetic rats and mice. Isologous pancreatic islet recipients (12 of 12) showed consistent and permanent reconstitution of normoglycemia and normal weight gain as well as readjustment to normal of intake of water, urine volume, and glucose excretion for greater than 10 months when compared to age-matched normal (ten) and diabetic (20) controls. Revascularized isologous islet grafts were found to be adherent to both visceral and parietal peritoneum. Pancreatic islet allografts (ten) and allografts and xenografts did not appear to differ markedly; both were characterized by dense round-cell infiltration within 5 days after transplantation.

Animals

The kidney in streptozotocin diabetic rats. Morphologic, ultrastructural, and function studies.

In order to study the nephropathy associated with experimental streptozotocin diabetes, serila morphologic, ultrastructural, immunohistologic, and functional studies were done in diabetic Lewis rats to study the course of the nephropathy. Early in the course of diabetes, these animals developed an increase in mesangial matrix, with electron-dense material, IgG, and C3 in the mesangium. These alterations were progressive. Mesangial bars, proximal tubular vacuolization, and myeloid bodies were also present. Progressive increase in protein excretion and increase in creatinine clearance were observed. Hyperglycemia was accompanied by weight loss, persistent glycosuris, hyperphosphaturia, and hypercalcuria. Urinary glomerular basement membrane-like protein and major urinary protein were decreased. Normal age-matched controls showed no abnormalities. Some of the changes observed in diabetic rats are present in human diabetes.

Animals

Orthotopic liver transplantation in ninety-three patients.

During the 11 1/2 year period ending 13 months ago, 93 consecutive patients were treated with orthotopic liver transplantation. Fifty-six of the recipients were 18 years old or younger, and the other 37 were adults. The most common indications for operation were biliary atresia, primary hepatic malignant tumor, chronic aggressive hepatitis and alcoholic cirrhosis. There has been a gradual improvement in results throughout the period of study, although to a satisfactory level. Twenty-seven of the 93 patients survived for at least one year after liver replacement with a maximum of six years, and 16 are still alive after 13 to 71 months. The 11 late deaths after one to six years were caused by chronic rejection, biliary obstruction, recurrence of hepatoma, systemic infection or hepatitis of the homograft. Rejection of the liver as judged by classical histopathologic criteria played a surprisingly small role in the heavy over-all mortality, accounting for less than 10 per cent of the deaths. Technical or mechanical problems, especially those of biliary duct reconstruction, were a far greater cause of failure, as were systemic infections. Six of the 37 adult recipients had lethal cerebrovascular accidents during, or just after, operation. When abnormalities of liver function developed in the postoperative period, the nearly automatic diagnosis of homograft rejection, in retrospect, proved to have been wrong in most instances. Further development of liver transplantation depends upon two kinds of progress. There must be reduction of operative and early postoperative accidents and complications by more discriminating patient selection, purely technical improvement and better standardization of biliary duct reconstruction. The second area will be in sharpening the criteria for the differnetial diagnosis of postoperative hepatic malfunction, including the liberal use of transhepatic cholangiography and needle biopsy. Only then can better decisions be made about changes in medication or about the need for secondary corrective surgical procedures.

Adolescent

Cryptococcosis after renal transplantation: report of ten cases.

Ten cases of cryptococcosis have been identified in a 13 year experience with more than 650 renal transplants. Eight patients had meningitis, one patient had a cerebral granuloma, and in one patient the infection appeared to be limited to the lungs. The central nervous system infection often masqueraded as brain tumor and was not suspected initially. The most useful diagnostic test was cerebrospinal fluid examination including India ink preparation. Various ther apeutic regimens with amphotericin B and 5-fluorocytosine were effective in suppressing the infection. A combination of low doses of amphotericin B, not affecting kidney function, with 5-fluorocytosine for at least 3 months was associated with remission of disease in five patients who still are alive, including three patients without recurrence for longer than one year. Five deaths 3 weeks to 4 years after the beginning of treatment were not due to cryptococcosis; death resulted from vascular disease and septiciemia in three of the four patients with known causes of death. Central nervous system cryptococcosis, with the exception of the rare cerebral granuloma, is associated with little inflammation. If early death from increased intracranial pressure or cerebral edema is prevented, prolonged therapy with amphotericin B and 5-fluorocytosine may be expected to control the infection, even in immunosuppressed patients.

Adult