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Biomedical subjects

J Huppert

Publications and source records attributed to J Huppert.

At least 37 records · Page 2Linked to original sources
PubMed1985

[Tethered conus syndrome or fixed spinal cord syndrome. Lumbosacral lipomas].

Fifty-eight cases presenting a tethered conus with spina bifida occulta are analysed. Twenty-three patients had a lipoma, the others had various malformations of the cord. Twenty patients had no symptom or sign, 38 had neurological symptoms and signs. Only 2 had no skin malformation. The aim of surgery is to reduce the volume of the lipoma, untether the cord, and reconstruct the posterior protection of the cord. Twenty-six patients were cured or improved, 12 patients were stabilized, 19 remained asymptomatic, 1 was worsened.

Abnormalities, Multiple↗
PubMed1985

Treatment of cerebrospinal fluid rhinorrhea by percutaneous lumboperitoneal shunting: review of 15 cases.

Fifteen patients with recalcitrant cerebrospinal fluid (CSF) fistula underwent the insertion of a lumboperitoneal shunt. The shunt consists of a two-piece Silastic tube and has been used in a population of 150 patients with communicating hydrocephalus, persistent postoperative meningocele, and benign intracranial hypertension. The spinal catheter is introduced subcutaneously and no flushing device is used. We studied three groups: 9 patients had a history of head trauma, and 7 of these had undergone one or several ineffective direct approaches to the dural leak. Four patients presented with a presumably congenital fistula. Two patients had persistent rhinorrhea due to previous intracranial procedures. Indium-111 cisternography was performed in 10 patients before lumboperitonel (LP) shunting and failed in 2 of those to document the site of leakage. Twelve patients showed cessation of rhinorrhea after LP shunting. In 4 of these, shunt-related complications responded to shunt removal with no further recurrence of rhinorrhea. Two patients underwent revision of the shunt. In 3 patients, the LP shunt failed to control the CSF leak and further intracranial procedures were indicated. The LP shunt provides an attractive and technically simple solution when direct methods of treatment have failed. Additionally, LP shunting should be considered as a primary mode of treatment in elderly patients or when impairment of CSF dynamics is documented by radionuclide cisternography and computed tomographic scanning. When an LP shunt is ineffective, shunt function should be checked by isotopic studies before additional surgery is performed.

Adult↗
PubMed1983

Depression of reverse transcriptase activity by hybridoma supernatants: a potential problem in screening for retroviral contamination.

Murine hybridoma cell lines generally produce retroviral particles (type A and/or type C), often in large numbers. We have measured reverse transcriptase activity in the supernatant of some 30 hybridoma lines of murine origin and found that the observed activity expressed as pmoles of [3H]-dGMP incorporated into an acid insoluble polymer, is frequently much lower than would be expected from the amount of retrovirus seen by electron microscopy in the corresponding cells. We demonstrate that this reduction is due to the presence of a nuclease which degrades the high molecular weight product but is not due to a change in the reverse transcriptase activity. This nuclease activity may be associated with mycoplasma contamination of the cell lines.

Animals↗
PubMed1983

Somatic cell hybrids.

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Cell Transformation, Neoplastic↗
PubMed1980

Retroviral antigens on gs- chf- leukocytes.

It has recently been suggested that the endogenous retroviruses present in many different species might be involved during stimulation of the immune system of their hosts. We have now studied the expression of two avian retroviral antigens p27 and gp85 in chicken lymphoid cells by indirect immunofluorescence (IIF) and by complement-dependent microcytotoxicity (CDM). We have now found that these viral antigens are expressed in peripheral blood leukocytes of adults and embryos and in splenic and bursal lymphocytes of Spafas gs- chf- chickens but they are not expressed in fibroblasts cultured from the feather follicles of the same individual adult birds nor in fibroblasts cultured from embryos of the same flock. The differential expression of viral antigens in leukocytes may be related to a specific property or function of these cells.

Animals↗
PubMed1980

[Immunochemical evidence for the specific binding of putrescine to plasma proteins including fibronectin].

Human plasma contains proteins capable of binding 14C putrescine by the action of Ca++ activated transglutaminase. These proteins have molecular weights from 32 to 220 K and above. One of these (with a molecular weight of 220 K) has been identified as fibronectin by the use of an antifibronectin antiserum. Evidence for a protein with a molecular weight identical to that of fibronectin has been obtained on PAGE analysis of the precipitate formed on incubating human serum with antipolyamine antiserum.

Calcium↗
PubMed1980

Herpes simplex type 1 infection of nonpermissive rat XC cells.

Herpes simplex virus type 1 (HSV-1) infection of non permissive XC cells (a rat cell line transformed by Rous sarcoma virus) was studied. Using virus labeled with 3H-thymidine it was shown that adsorption is similar to that in a permissive system. By electron microscopy enveloped particles were observed in cytoplasmic vesicles in XC cells but not in the permissive system. However input viral DNA was degraded both in non permissive cells (XC) and permissive cells (HEp-2) and the degradation products were found incorporated into cellular DNA in the first case or into viral DNA in the second case. In the non permissive XC cells, it was possible to detect a small amount of incorporation of radioactive precursors into the viral DNA, identified by its buoyant density in CsCl of 1.726 g/cm3 and by hybridization with viral DNA. This DNA has the size of the native viral genome and its uptake of radioactive precursors was only partially inhibited by phosphonoacetic acid, a specific inhibitor of HSV-DNA polymerase. With permissive HEp-2 cells in the presence of such inhibitor, the obtained data are roughly the same as with XC cells, both in the presence or in the absence of phosphonoacetic acid. These results suggest that the observed viral DNA synthesis in XC cells is not a true replication but, further, a repair synthesis and, also, that the same events might take place in the permissive system before the onset of viral DNA replication.

Adsorption↗
PubMed1980

Nuclear processing of viral high-molecular-weight RNA in cells infected with herpes simplex virus type 1.

Nuclear RNA isolated from cells infected by herpes simplex virus type 1, strain F, was fractionated on formamide-sucrose gradients into two major classes, greater and less than 45S. These two classes of labeled nuclear RNA were hybridized to viral DNA fragments generated by digestion with the restriction enzymes HindIII and BglII. Early in infection, only a few DNA fragments hybridized to RNA, with slight differences between the two classes. Late in infection, all DNA fragments hybridized, showing that all viral RNA was present in large precursor molecules greater than 14 kilobases. The fragments that correspond to late gene products hybridized more of the small RNA than the large RNA. This suggests that the mRNA corresponding to late genes accumulated after the large precursors have been cleaved. Large (greater than or equal to 45S) and small (< 45S) nuclear RNA and cytoplasmic RNA from cells late in infection were hybridized in excess to in vitro-labeled HindIII M and L fragments. More than 50% of the HIndIII M fragment annealed with the large nuclear RNA, but only 36% of it annealed with the cytoplasmic RNA. The HindIII L fragment hybridized large nuclear RNA and cytoplasmic RNA to the same extent (30% and 26%). These results suggest that RNA complementary to the HindIII M fragment, which is the template for immediate early polypeptides, was regulated in the nuclei at the posttranscriptional level. This seems to suggest that temporal regulation of RNA cleavage occurs in the nucleus.

DNA, Viral↗
PubMed1979

[Modification of human adenovirus type 7 after culture in guinea pig brain cells in vitro].

Multiplication of human adenovirus 7 (Ad7) is restricted in subcultures of adult Guinea Pig brain cells. It was however possible to recover enough infectious virus to purify it, and to study its properties. Several properties are similar to that of Ad 7 produced in HeLa cells but differences in sensitivity to cesium chloride and in its polypeptide composition were found.

Adenoviruses, Human↗
PubMed1979

Isolation and characterisation of a defective measles virus from a subacute sclerosing panencephalitis patient.

A cytopathic measles virus was isolated from a brain biopsy of a subacute sclerosing panencephalitis (SSPE) patient. The agent could be transferred to Vero cells by cocultivation, but the infectivity always remained cell-associated -ie, a defective virus infection. The cell-associated nature of the virus was retained through 25 passages in Vero cells. Intracerebral inoculation of hamsters (2-6 days old) with the cocultured Vero cells gave rise to 100% mortality in 5-7 days. The virus retained its cell-associated nature after passage in hamsters. Electron microscopy of the brain and Vero cocultures showed the presence of virus-like ribonucleoparticles mainly in the nucleus. The presence of viral antigens in the nucleus, cytoplasm, and on the plasma membranes was confirmed by immunofluorescence. Using a combination of immunological and biochemical techniques, it was shown that all the viral proteins were synthesized with the exception of the haemagglutinin. Inclusion of the fusion inhibitor SV4814 (CBZ-D phenylalanine-L-phenylalanine-L-arginine-NO2) in the culture medium led to the elimination of the SSPE infection.

Adult↗
PubMed1979

Replication cycle of Newcastle disease virus in three host cells of different permissiveness.

Various degrees of permissiveness for NDV have been described in different cell lines. In the present work three systems were investigated: bovine kidney (MDBK) cells, chick embryo (CE) cells and mouse L cells producing 50 to 100 p.f.u., 2 to 10 p.f.u. and less than 0.1 p.f.u./cell, respectively. Analysis of the radioactive virus messenger RNAs (vmRNAs) accumulating in actinomycin D-treated cells throughout the infection cycle revealed that, except for the absence of one 18S vmRNA species in L cells, all vmRNA components were formed in the three cell types, although variations occurred in their total and relative amounts from one cell type to another. Kinetic studies of vmRNA synthesis confirmed the absence of one 18S vmRNA species in L cells and also showed that the labelling rate of this vmRNA component is higher in CE cells. Virus proteins synthesized in the infected cells were labelled with 14C-amino acids and analysed by polyacrylamide gel electrophoresis. All the major NDV polypeptides were formed as expected in both CE and MDBK cells but only traces were detected in L cells. In contrast in a cell-free translation system from wheat germ, all of the NDV major proteins were synthesized using RNA extracted from the three infected cell types. Moreover, the total radioactivity incorporated into NDV proteins was twice as great with CE cell RNA and five times as great with L cell RNA than with equivalent quantities of RNA from MDBK cells.

Animals↗
PubMed1978

The use of a measles latex reagent for the determination of measles antibodies and in a specific test for multiple sclerosis.

Measles virus antigens covalently linked to latex spheres were used for measuring measles-specific antibodies in a direct agglutination test either in microtitre plates or as a rapid slide-agglutination test. The titres were compared to that obtained by conventional assays. The measles-latex spheres were also used as the antigen for a radio-immuno assay. By incorporating a 14C-radioactive marker into the measles-latex spheres their interaction with lymphocytes from multiple sclerosis and control patients was determined. Lymphocytes from multiple sclerosis patients reacted with a higher percentage of beads at low bead/lymphocyte ratios compared with controls, whereas the reverse was found when the ratio of beads was increased.

Antibodies, Viral↗
PubMed1978

The preparation of latex particles with covalently bound polyamines, IgG and measles agglutinins and their use in visual agglutination tests.

Carboxylated latex particles were substituted with side arms terminating in primary amine and hydrazine groups. The particles were coupled to aldehyde groups generated on glycoproteins which were treated with sodium periodate. Particles having the alipathic primary amine putrescine hapten as the sole substituent and particles linked to glycoproteins such as measles agglutinins and IgG were used to detect the presence of the corresponding antibodies or antigens in biological fluids by agglutination tests.

Agglutination Tests↗
PubMed1978

Poly (A) polymerase activity in L cells following encephalomyocarditis virus infection.

Poly (A) polymerase activity has been measured in crude cytoplasmic extracts of mouse L cells infected with encephalomyocarditis (EMC) virus. After infection there is first a decrease in enzyme activity followed by an increase which itself precedes detectable virus RNA and protein synthesis. The activity of the enzyme then declines before the release of mature virions and cell death take place. The early inhibition of poly (A) polymerase activity is correlated with the virus-induced shut-off of cellular protein synthesis but it is not due to inhibition of the synthesis of cellular enzyme and occurs in the absence of virus replication. The poly (A) polymerase is not synthesized after infection and modification of its activity can be reversed late in the virus cycle. These results indicate that host poly (A) polymerase activity can be regulated by the virus and further show that there is a correlation between the modification of poly (A) polymerase activity and the biosynthesis of poly (A).

Cycloheximide↗