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Biomedical subjects

J L Melnick

Publications and source records attributed to J L Melnick.

At least 91 records · Page 5Linked to original sources
PubMed1985

Inhibitory effect of glucocorticoid hormones on the growth of Inoue-Melnick virus.

Glucocorticoid hormones inhibited the early stage of propagation of Inoue-Melnick virus in a dose-dependent manner in human diploid cell cultures. Prednisolone and hydrocortisone achieved complete inhibition of replication of the three Inoue-Melnick virus serotypes at concentrations of 0.2 X 10(-4) and 10(-5) M, respectively; strong inhibition was found even at 10(-5) and 10(-6) M, respectively. The steroid hormones did not show a direct effect on the virus.

Cell Line↗
PubMed1985

Molecular cloning and characterization of the cDNA coding for hepatitis B virus surface antigen.

Hepatitis B virus surface antigen (HBsAg) mRNA has been enriched from a hepatoma cell line (PLC/PRF/5) by specific polysome immunoprecipitation and used for cDNA cloning. A HBsAg cDNA clone was identified by in situ hybridization with a cloned viral probe. It was characterized by restriction endonuclease mapping and DNA sequence analysis. Molecular hybridization of PLC/PRF/5 cellular DNA and RNA to [32P]-labeled HBsAg cDNA revealed the integration of at least six copies of the hepatitis B virus (HBV) DNA into the host genome and expression of three DNA species containing HBsAg-specific sequences. The possible role of HBV in the oncogenesis of primary hepatocellular carcinoma is discussed.

Carcinoma, Hepatocellular↗
PubMed1985

Lyophilized combination pools of enterovirus equine antisera: new LBM pools prepared from reserves of antisera stored frozen for two decades.

This paper describes the preparation and test procedures for a second batch of lyophilized LBM combination antiserum pools, A through H, used for identifying 42 enteroviruses. Each pool is selectively composed of 10 or 11 of 42 individual enterovirus equine sera so that it contains 500 antibody units of each serum component per 0.1 ml. The new pools have been constituted from equine monovalent antisera that were prepared during the period 1962-67 and then evaluated and standardized in a series of collaborative international studies. An essential aspect of preparing the new pools was ensuring that the individual sera had retained high antibody titres through the long period of storage. At the time of retesting, the original stocks of these monovalent sera had been stored frozen at -20 degrees C for periods ranging from 16 to 20 years.

Animals↗
PubMed1984

Enhancement of viral hepatitis B antibody (Anti-HBs) response to a synthetic cyclic peptide by priming with anti-idiotype antibodies.

In vivo injections of anti-idiotype antibodies were used to prime the immune system of mice to hepatitis B surface antigen (HBsAg). Anti-idiotype reagents in conjunction with a cyclic synthetic peptide analogous to positions 122-137 of HBsAg induced an antibody response to HBsAg (anti-HBs) comparable to that obtained with a single injection of intact HBsAg particles. In addition, high anti-HBs titers were produced in mice injected with HBsAg following anti-idiotype priming. These data indicate that anti-idiotype antibodies may be useful in priming the immune system of a host to a potential infectious agent.

Animals↗
PubMed1984

Antibody to hepatitis B virus induced by injecting antibodies to the idiotype.

Anti-idiotype reagents that recognize a common idiotype associated with antibody to hepatitis B surface antigen (anti-HBs) were used to induce anti-HBs in mice. The anti-idiotype-induced anti-HBs was found to recognize the group-specific a determinant of hepatitis B surface antigen and to express an interspecies idiotype. These findings suggest that anti-idiotypes may be useful as vaccines or vaccine primers.

Animals↗
PubMed1984

Herpesviridae in the endothelial and smooth muscle cells of the proximal aorta in arteriosclerotic patients.

Punch-biopsy specimens were obtained from uninvolved areas of the proximal aorta of each of 60 patients with atherosclerosis undergoing cardiovascular surgery. Electron microscopic study of the smooth muscle and endothelial cells of the aortas showed cellular hyperplasia, nuclear and nucleolar atypia. Virions of the Herpesviridae family were observed in ten of the patients. They were detected in occasional smooth muscle and rare endothelial cells. Specimens were taken from three separate sites of each aorta and distributed into five blocks for each patient. In only a single block from each of the ten positive patients could virus be identified. Nine of the ten virus-positive patients also exhibited intracytoplasmic microtubular inclusions. In four patients only the microtubular inclusions were seen. Microcapillaries were observed in the midportion of the media, which we consider to be an attempt of a repair process.

Adult↗
PubMed1984

Round robin investigation of methods for the recovery of poliovirus from drinking water.

Six laboratories actively involved in water virology research participated in a methods evaluation study, conducted under the auspices of the American Society for Testing and Materials Committee on Viruses in the Aquatic Environment, Task Force on Drinking Water. Each participant was asked to examine the Viradel (virus adsorption-elution) method with cartridge-type Filterite filters for virus adsorption and organic flocculation and aluminum hydroxide-hydroextraction for reconcentration. Virus was adsorbed to filter media at pH 3.5 and eluted with either glycine buffer (pH 10.5) or beef extract-glycine (pHG 9.0). Considerable variation was noted in the quantity of virus recovered from four 100-liter samples of dechlorinated tapwater seeded with low (350 to 860 PFU) and high (1,837 to 4,689 PFU) doses of poliovirus type 1. To have a more uniform standard of comparison, all the test samples were reassayed in one laboratory, where titers were also determined for the virus seed. Test results of the Viradel-organic flocculation method indicated that the average percentage of virus recovery for low-input experiments was 66%, with a range of 8 to 20% in two laboratories, 49 to 63% in three laboratories, and 198% in one laboratory. For the high-input experiments, two laboratories reported recoveries of 6 to 12%, and four laboratories reported recoveries of 26 to 46%. For the Viradel aluminum hydroxide-hydroextraction procedure, two laboratories recovered 9 to 11%, whereas four obtained 17 to 34% for low-input experiments. For the high-input tests, two laboratories reported a recovery of 3 to 5%, and four recovered 11 to 18% of the seeded virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Hydroxide↗
PubMed1984

Isolation of enteroviruses from water, suspended solids, and sediments from Galveston Bay: survival of poliovirus and rotavirus adsorbed to sediments.

The distribution and quantitation of enteroviruses among water, suspended solids, and compact sediments in a polluted estuary are described. Samples were collected sequentially from water, suspended solids, fluffy sediments (uppermost layer of bottom sediments), and compact sediment. A total of 103 samples were examined of which 27 (26%) were positive for virus. Polioviruses were recovered most often, followed by coxsackie B viruses and echoviruses 7 and 29. Virus was found most often attached to suspended solids: 72% of these samples were positive, whereas only 14% of water samples without solids yielded virus. Fluffy sediments yielded virus in 47% of the samples, whereas only 5% of compact bottom-sediment samples were positive. When associated with solids, poliovirus and rotavirus retained their infectious quality for 19 days. The same viruses remained infectious for only 9 days when freely suspended in seawater. Collection of suspended solids at ambient water pH appears to be very useful for the detection of virus; it has advantages over collecting and processing large volumes of water, with accompanying pH adjustment and salt addition for processing.

Animals↗
PubMed1984

Classification of Inoue-Melnick virus into three antigenic types.

Antigenic analysis of Inoue-Melnick virus, formerly called SMON virus, showed that isolates from patients with subacute myelo-optico-neuropathy (SMON) in Japan, thus far tested, belonged to a single antigenic type (type 1). However, Inoue-Melnick virus isolates obtained so far in the United States chiefly from patients with multiple sclerosis could be classified into three types: type 1, type 2, and an intermediate type. At the present state of knowledge, the virus has not been proven to be the causative agent of disease, hence its provisional designation as IMV.

Antigens, Viral↗
PubMed1984

Reverse-flow apparatus for enhanced colorimetric detection of bacteriuria.

The reverse-flow apparatus is a new device for enhancing the detection of bacteria in urine. Bacteria are trapped onto a customized filter, and the pigments, crystals, and other interfering substances in the urine pass through the filter and are discarded. The bacteria are backflushed and are recovered as a concentrate, and the concentrate is then processed through the previously described colorimetric bacteriuria detection device. A total of 1,000 urine samples were obtained from randomly selected patients and were cultured on agar. Upon enumeration of the colonies, 160 urine samples were shown to contain more than 10(5) CFU/ml. In the bacteriuria detection device, 150 urine samples could not be processed (pigmenters and cloggers), and of the 850 urine samples processed, 127 were culture positive for 10(5) CFU/ml or greater, and 150 urine samples contained between 10(4) and 10(5) CFU/ml. At 10(5) CFU/ml, there were 140 false-positives and 14 false-negatives. When duplicate urine samples were processed through and concentrated by our new reverse-flow apparatus, all samples, including the above pigmenters and cloggers, could be tested in the bacteriuria detection device. The 150 unprocessable samples described above yielded 33 additional bacteria-positive urines, 23 at the 10(5)-CFU/ml cutoff and 10 at the 10(4)-to-10(5)-CFU/ml cutoff. There were 105 false-positives at 10(5) CFU/ml and only 2 false-negatives at the same level of bacteria. At 10(4) to 10(5) CFU/ml there was only 1% false-positive and 4% false-negative. The reverse-flow apparatus allows greater specificity and sensitivity in the rapid bacteriuria test. Urine containing 10(4) CFU/ml or more can now be detected with a 96% sensitivity in a total processing time of less than 2 min.

Bacteriological Techniques↗
PubMed1984

Characterization of IM virus, which is frequently isolated from cerebrospinal fluid of patients with multiple sclerosis and other chronic diseases of the central nervous system.

A transmissible agent, the IM virus, antigenically related to the Japanese subacute myelo-optico-neuropathy virus, has been isolated from several human cerebrospinal fluids obtained from American patients with multiple sclerosis and other chronic diseases of the central nervous system. The isolates were propagated in human diploid fibroblast (MRC5) cells, and virus was released into the culture medium in the absence of overt cytolysis. Infection of MRC5 cells resulted in a subtle alteration in the normal growth pattern of the cells. In unstained cultures, the cell changes were so mild that it was necessary to carry out all virus assays under code to eliminate bias. Cells in late passages were more susceptible than vigorously growing cells in early passages. Analysis of the kinetics of replication revealed that newly synthesized progeny virus was first detected about 12 h postinfection, that maximal virus release occurred by 48 h postinfection, and that virus production was persistent throughout an 8-day period. Several inhibitors of DNA synthesis were effective in blocking viral replication, including cytosine arabinoside, iododeoxyuridine, and phosphonoacetic acid. A substantial decrease in infectivity was observed upon treatment of IM virus with ether, suggesting that a lipid-containing structure is essential for infectivity. Ultrafiltration studies approximated the size (diameter) of IM virus to be between 100 and 200 nm.

Amyotrophic Lateral Sclerosis↗
PubMed1984

Localization of hepatitis A virus antigen to specific subcellular fractions of hepatitis-A-infected chimpanzee liver cells.

The localization of hepatitis A virus antigen to specific subcellular fractions of infected chimpanzee liver cells was studied by solid-phase radioimmunoassay following a mild subcellular fractionation procedure designed to separate various organelles from the cytosol and the nuclei. Most of the antigenic activity (93%) was evenly divided between the cytosol fraction and the microsomal suspension. Within the microsomal fraction, more than 75% of the detectable antigen was associated with the smooth endoplasmic reticulum. Less than 4% of the total antigenic activity was localized to the nucleus. These data provide additional evidence that replication of hepatitis A virus occurs primarily within the cytoplasm of the host cell in close association with cellular membranes, consistent with that observed for other members of the genus Enterovirus.

Animals↗
PubMed1984

The paralytic poliomyelitis epidemic of 1978 in Jordan: epidemiological implications.

Poliomyelitis is endemic in Jordan, but until 1978 there were no epidemics. In that year, 66 children were admitted to the Jordan University Hospital with a paralytic illness, compared with 13 in 1979 and 11 in 1980. The epidemic reached a peak in the summer and fall of 1978. While 54% of the patients had not received any vaccine, 19% had received 3 doses of oral poliovaccine; 82% of the cases were in children less than 2 years of age, and all belonged to the lower socioeconomic group. There were 28 deaths with complications of the disease.Poliovirus was isolated from 10 out of 14 rectal swab samples examined (9 with poliovirus 1, 1 with poliovirus 2), and from 4 out of 13 throat specimens from the same patients. It is concluded that as a result of improving living standards in Jordan and neighbouring countries, more epidemics may occur unless immunization efforts against poliomyelitis are intensified.

Age Factors↗
PubMed1984

The Hemo-matic Analyzer: a new occult blood testing device.

It is now recognized that screening for fecal occult blood is useful to alert the clinician to possible colon cancer in an early stage. The guaiac impregnated card is not widely used because patients must maintain strict diets omitting red meat, peroxidase-containing foods, iron supplements, and ascorbic acid. The Hemo-matic Analyzer uses a special filter to adsorb fecal Hb which is then automatically washed free of interfering substances and quantitatively identified. The filter electrostatically binds Hb and not pepsinized blood or substances that interfere with occult blood testing. We evaluated the sensitivity of this device and compared it to the Hemoccult II test in vivo and in vitro. It was approximately six times more sensitive than Hemoccult II and was not influenced by the presence of ascorbic acid, plant peroxidase, or ingestion of a large quantity of rare red meat. In addition, the samples remained positive more than 10 wk after preparation. The Hemo-matic Analyzer is a useful new device that offers many advantages over Hemoccult card testing for screening for colon cancer.

Adult↗
PubMed1983

Posttransfusion hepatitis type A.

Hepatitis A virus (HAV) transmission through blood is a rare but potential cause of posttransfusion hepatitis. We can now document such a case supported by laboratory evidence of HAV in the donor blood. A 10-year-old girl manifested icteric hepatitis A 31 days after receiving a single unit of packed RBCs from a donor who subsequently experienced hepatitis A and died in hepatic failure. Hepatitis A virus antigen was detected in the donor's hepatocytes and in plasma obtained from the original donor unit. The density in cesium chloride of the HAV antigenic activity from the liver and plasma ranged from 1.33 to 1.37 g/cu cm, which is similar to that reported for infectious HAV particles. The implicated donor plasma had normal aminotransferase levels and was negative for antibody to HAV. Inoculation of this plasma into a chimpanzee resulted in the development of hepatitis A 23 days later based on the appearance of fecal HAV antigen, hepatitis, and IgM anti-HAV seroconversion. These data clearly document the presence of HAV in the donor sample that produced posttransfusion hepatitis A.

Antibodies, Viral↗