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Biomedical subjects

S Stein

Publications and source records attributed to S Stein.

At least 109 records · Page 6Linked to original sources
PubMed1990

Oral flecainide for the treatment of drug-resistant ventricular ectopy.

Flecainide acetate was administered at a dose of 100 mg twice daily to 15 patients with drug-resistant ventricular ectopy. Eleven patients had evidence of organic heart disease. Left ventricular function was normal in 13 patients, and 2 patients had mild and moderate left ventricular dysfunction respectively. All patients underwent a control (off drugs) and a flecainide Holter ECG. Flecainide suppressed ventricular ectopy by greater than 70% in 13 patients (86.6%), suppressed bigeminal beats by greater than 90% in 13 (86.6%), suppressed ventricular couplets by greater than 90% in 12 of 14 patients (85.7%), and completely suppressed runs of nonsustained ventricular tachycardia in 6 of 9 patients (66.6%). In only one patient who showed a 69% suppression of ventricular ectopy did ventricular couplets increase. No side effects of the drug were noted. We conclude that flecainide at a dose of 100 mg twice daily is highly effective in suppressing ventricular ectopy that is resistant to other anti-arrhythmic agents.

Administration, Oral↗
PubMed1990

Tissue response to intramuscular and intraperitoneal injections of ketamine and xylazine in rats.

Ketamine-xylazine is a widely accepted anesthetic combination for laboratory animals. Although frequently recommended for administration by intramuscular (IM) or intraperitoneal (IP) routes, the potential for tissue damage following either route of administration in the rat has not been investigated. This study evaluated tissue damage after IM use at two doses in Fischer 344 and Sprague-Dawley rats. Tissue reactions following IP injections of ketamine-xylazine were compared to lesions produced by IM injections in animals euthanatized on 1, 3 and 14 days post-injection. Results showed muscle necrosis present in nearly all ketamine-xylazine injected limbs. Intraperitoneal injections produced no significant lesions in the peritoneal cavity when careful IP injection techniques were used. Ketamine-xylazine should not be administered by the IM route for survival procedures in these two widely used strains of rats.

Animals↗
PubMed1989

Amino acid analysis on polyvinylidene difluoride membranes.

A procedure for the amino acid analysis of proteins electrotransferred to polyvinylidene difluoride (PVDF) membranes is described. The proteins are first separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and then electroblotted onto a PVDF membrane. After staining with Coomassie brilliant blue, the visualized protein bands are excised from the membrane. Each band is placed in a vial and subjected to gas-phase hydrolysis in 6 N HCl in a vacuum desiccator at 110 degrees C. The amino acids are extracted from the membrane into 0.1 N HCl/30% CH3OH and analyzed by reverse-phase HPLC using postcolumn o-phthalaldehyde-derivatizing reagent. The method was shown to give reproducible and reasonably accurate compositions for several proteins, as well as to provide an estimate of protein content. As little as 10 pmol of a 67-kDa protein can be determined.

Amino Acids↗
PubMed1989

Abortion, stillbirth, neonatal death, and nutritional myodegeneration in a rabbit breeding colony.

Vitamin E deficiency was found to be the cause of reproductive failure and nutritional myodegeneration in a rabbit breeding colony. The diagnosis was based on the low vitamin E concentration of doe liver (5.73 micrograms/g) associated with myodegeneration of tongue, skeletal muscle, and heart and the absence of other abnormal microbiologic and parasitologic findings. Supplementation of the diet with wheat germ oil returned the does' fertility to normal, and abortion, stillbirth, and neonatal death ceased.

Abortion, Veterinary↗
PubMed1989

Psychological correlates of survival in nursing home cancer patients.

Demographic, cancer, physical functioning, and psychological data were collected for 90 late-stage cancer, newly admitted nursing home patients. Those who died within 3 months (28%) more often acknowledged their condition as terminal, anticipated greater environmental stress and adjustment problems, and had poorer self-esteem. For cancer patients undergoing the stress of nursing home placement, feelings of hopelessness and helplessness are associated with earlier death.

Attitude to Death↗
PubMed1989

Theiler's murine encephalomyelitis virus neutralization escape mutants have a change in disease phenotype.

DA strain of Theiler's murine encephalomyelitis virus produces a persistent demyelinating infection. We previously produced escape mutant viruses that are resistant to a neutralizing monoclonal antibody and have a mutation in VP1 amino acid residue 268 in a neutralization site (Y. Ohara, A. Senkowski, J. Fu, L. Klaman, J. Goodall, M. Toth, and R.P. Roos, J. Virol. 62:3527-3529, 1988). In contrast to wild-type DA strain, these escape mutants produce little if any demyelinating disease after inoculation into weanling mice.

Animals↗
PubMed1989

Infectious cDNA clones of the DA strain of Theiler's murine encephalomyelitis virus.

The DA strain and other members of the TO subgroup of Theiler's murine encephalomyelitis viruses cause a persistent demyelinating infection, whereas the GDVII strain and other GDVII subgroup strains cause an acute lethal polioencephalomyelitis. We generated an infectious DA cDNA clone inserted into a transcription vector. Virus derived from transfection of transcripts produced a demyelinating disease indistinguishable from that of wild-type virus. The infectious clone provides a critical reagent for the production of interstrain recombinant viruses to help identify genetic loci responsible for the biological activities of the strains.

Animals↗
PubMed1989

Effect of nursing home staff training on quality of patient survival.

This study tests the effects of nursing home staff training in care for the dying on the quality of life of terminally ill patients. Ten matched community nursing homes were assigned randomly to experimental (training) or control (no training) conditions Patients (N = 306) admitted to the homes were assessed at admission, one month, and three months concerning quality of life as measured by depression, alienation, self-esteem, and locus of control. Satisfaction with care was also measured at one and three months. Patients in trained homes had less depression and greater satisfaction with care than patients in control homes at one and three months. Training effects were similar in all of the five homes. The study shows that a favorable impact on patient care can be achieved when staff in nursing homes are trained to work with dying patients.

Aged↗
PubMed1989

A new anesthetic agent for use in the gerbil.

Gerbils have been neglected in published reports on anesthesia. This study compared several dosages of Telazol used for anesthesia in the gerbil. Each group of animals injected with Telazol was evaluated for onset and duration of anesthesia and analgesia. Results showed Telazol to be a safe anesthetic and when dosed at 60 mg/kg to be suitable for major surgical procedures. Lower dosages of Telazol, in contrast, provided immobility and analgesia suitable for less nocioceptive and noninvasive experimental manipulations. Dosages of Telazol required for surgical depth of analgesia and anesthesia were accompanied by a prolonged recovery time. Gerbils should be monitored closely to insure a safe recovery when using the higher dosages.

Anesthesia↗
PubMed1988

Preparation and chromatographic use of 5'-fluorescent-labelled DNA probes.

A convenient procedure for synthesizing and purifying fluorescently-labelled short DNA probes is reported. DNA probes were chemically synthesized on an automated instrument using the "Aminolink" reagent in the final cycle to attach a primary amino group at the 5'-terminus in the final step. The synthetic oligonucleotides were purified by polyacrylamide urea gel electrophoresis, followed by reversed-phase high-performance liquid chromatography (HPLC). The oligomers were then allowed to react with a fluorescent compound, and the products were separated by HPLC with consecutive detection by UV absorption and fluorescence. Gel permeation chromatography demonstrated that the fluorescent probes were able to form stable hybrids with complementary oligodeoxynucleotides. Furthermore, essentially 100% of the purified fluorescent probe was capable of hybridizing to its complementary strand. Special precautions in handling the fluorescent probes, such as stability, were investigated.

Chromatography, High Pressure Liquid↗
PubMed1988

Enhanced in vivo therapy of pulmonary metastases with interferon and interleukin-2.

Interleukin-2 (IL-2) can mediate in vivo tumor regression at high doses. To enhance this efficacy, we studied the effect of adding a human hybrid recombinant interferon alpha A/D (rHuIFN-alpha-A/D) because of its known in vitro augmentation of immune-mediated tumoricidal activity. C56BL/6 mice bearing established pulmonary metastases induced by the iv injection of the methylcholanthrene-induced fibrosarcoma MCA 106 were treated for 12 days with intraperitoneal injections of (1) Hanks' balanced salt solution, (2) recombinant IL-2, (3) rHuIFN-alpha-A/D, and (4) a combination of IL-2 and HuIFN-alpha-A/D. IL-2 and interferon each had some antitumor activity. However, maximal reduction of pulmonary metastases consistently resulted from combining IL-2 with interferon. In two of four experiments, this combination was significantly better compared to either IL-2 or interferon treatment alone. The most potent regimen was 12 days of IL-2 (50,000 units bid) together with rHuIFN-alpha-A/D (50,000 units ip qd). No consistent pattern of proliferative or cytotoxic activity was found against a panel of stimulator and target cells. These results demonstrate enhanced antitumor efficacy of combining recombinant interferon alpha and IL-2 against established pulmonary metastases. Potential clinical applications are suggested by these data.

Animals↗
PubMed1988

Molecular cloning and sequence determination of DA strain of Theiler's murine encephalomyelitis viruses.

Theiler's murine encephalomyelitis viruses (TMEV) belong to the Picornaviridae, and are divided into two subgroups. TO subgroup strains produce a persistent demyelinating central nervous system infection in mice, while GDVII subgroup strains cause acute polioencephalomyelitis. We generated three overlapping clones of the genome of DA strain, a member of TO subgroup. Sequence analysis revealed that the genome is 8093 nucleotides long with a poly(A) tail. The 5' noncoding region stretches from nucleotides 1 to 1065 and lacks a poly(C) tract. The open reading frame stretches from 1066 to 7968 and encodes 2301 amino acids. DA strain sequence is more closely related to members of the Cardiovirus genus than to members of other Picornavirus genera. Comparison with sequence of BeAn strain, another TO subgroup strain, showed that the P1 area has the greatest number of differences, while the noncoding regions are more well-conserved. The three overlapping clones will be important in recombinant infectious cDNA studies between strains of both subgroups.

Amino Acid Sequence↗
PubMed1988

Recombinant rat and murine immune interferons are phosphorylated at a single site, Ser132.

Recombinant rat (Ra) and murine (Mu) immune interferons (IFN-gamma) were found to be phosphorylated by bovine heart muscle cAMP-dependent protein kinase at a single site, in contrast to human (Hu) IFN-gamma, which was reported to be phosphorylated at two different serine residues. Chromatography of a Staphylococcal aureus V8 protease digest of Ra or MuIFN-gamma indicated that the site of phosphorylation was in the carboxy-terminal undecamer fragment of the protein. Due to inherent problems in measuring both phenylthiohydantoin-serine (PTH-serine) and PTH-phosphoserine with an automated sequenator, a novel approach, involving partial Edman degradation of aliquots of the peptide followed by high performance liquid chromatography (HPLC) analysis, was developed. It was determined that Ser132 is the exclusive site of phosphorylation for both IFNs.

Amino Acid Sequence↗