Biomedical subjects

J A Hopkins

Publications and source records attributed to J A Hopkins.

6 recordsLinked to original sources

PubMed1992

Single pass sequencing and physical and genetic mapping of human brain cDNAs.

We have performed single pass sequencing of 1,024 human brain cDNAs, over 900 of which seem to represent new human genes. Library prescreening with total brain cDNA significantly reduced repeated sequencing of highly represented cDNAs. A subset of sequenced cDNAs were physically mapped to their chromosomal locations using gene-specific STS primers derived from 3' untranslated regions. We have also determined that human brain cDNAs represent a rich source of gene-associated polymorphic markers. Microsatellite-containing cDNAs can be physically mapped and converted to highly informative genetic markers, thus facilitating integration of the human physical, expression and genetic maps.

Base Sequence↗

PubMed1992

Molecular probe analysis of Shigella dysenteriae type 1 isolates from 1940 to 1987.

Fourteen strains of Shigella dysenteriae type 1 (Shiga bacillus) isolated from people in diverse locations from 1940 to 1987 were studied. Southern hybridization with three cloned Escherichia coli genes, Shiga-like toxin I (SLTI), frd, and ompF, was used to determine restriction fragment length polymorphism (RFLP) of the genomic DNA of these strains. Digestion with each of four restriction endonucleases generated fragments of identical size to which the frd and ompF hybridized for each of the 14 strains, indicating the conservation of these genes and their flanking sequences. In contrast, after digestion with HindIII, EcoRV, and ClaI and probing with SLTI, there were RFLP among the strains. The results showed three clones of the Shiga bacillus, and suggested that dissemination of a single clone may continue for decades within a wide geographical area.

Bacterial Toxins↗

PubMed1991

Adjunctive antimicrobials in surgery of soft tissue infections: evaluation of cephalosporins and carbapenems.

The authors report three trials of B-lactams and carbapenems for soft tissue infections treated on a surgical service: 1) cefmetazole versus cefoperazone, n = 44; 2) cefotetan versus cefoxitin, n = 24; and 3) meropenem versus imipenem, n = 44. A total of 138 hospitalized patients were enrolled with 112 meeting evaluability criteria. Four hundred twenty-three isolates were cultured (mean, three/patient) of which 67 per cent were aerobes and 33 per cent anaerobes. Cure rates for each trial were: 1) 93 per cent; 2) 92 per cent; 3) 100 per cent. Failures were caused by resistant organisms (Streptococcus group D, Bacteroides fragilis and Pseudomonas) appearing in incompletely drained infection sites. Three patients receiving meropenem had adverse effects (headache, nausea) and one receiving cefoxitin (truncal rash). Operative drainage and debridement remain the critical elements in therapy. Agents with longer half lives allowing twice daily dosing (cefmetazole and cefotetan) were as effective and less expensive than multiple doses of short-acting agents. The extended spectrum carbapenems are most useful for severe infections or resistant organisms.

Adult↗

PubMed1979

Behavior of vaccine revertants of temperature-sensitive mutants of influenza virus in ferret tracheal organ culture.

A live attenuated influenza vaccine candidate was not genetically stable when administered to some children who lacked antibody to surface proteins of the virus. To obtain additional biological information about these revertants, the vaccine strain, the wild-type parental strain, and isolates recovered from inoculated children during a vaccine trial were evaluated in ferret tracheal organ culture for effects on the ciliated epithelium and replication at both permissive and restrictive temperatures. The studies revealed that the vaccine strain destroyed cilia and replicated to high titer at its permissive temperature (33 degrees ) but caused minimal damage and replicated to very low titer at its restrictive temperature (37 degrees C). The wild-type parent destroyed cilia at both 33 and 37 degrees C. Isolates which were no longer temperature sensitive (ts(+)) destroyed cilia at both restrictive and permissive temperatures and grew to high titer. Isolates which retained the ts phenotype behaved as the vaccine strain in this system. The ts(+) virus recovered from volunteers behaved like the wild-type parent, which suggests that these viruses had not merely lost their ts phenotype, but had undergone reversion to wild type. Important information about the genetic stability of temperature-sensitive influenza vaccine strains recovered from volunteers can be obtained by evaluating them in ferret tracheal organ culture.

Animals↗

PubMed1978

Resuscitation algorithm for management of acute emergencies.

Assuming that unrecognized or inadequately corrected hypovolemia results in higher mortality and morbidity rates, we developed a systematic approach to resuscitation that would: 1) identify criteria to aid in the recognition of hypovolemia and ensure the expeditious correction of this defect without interfering with diagnostic workup and management; 2) define criteria to prevent fluid overload which may jeopardize the patient's course, and 3) express these criteria in an explicit, systematic, patient care algorithm, ie, protocol, useful to both the resident and the practicing physician. We are now conducting prospective clinical trials with one service using the algorithm and the others acting as the control group. Preliminary results comparing patient outcomes suggest that the algorithm improves patient care by shortening resuscitation time and results in fewer hospital days, intensive care unit days, febrile days, and days on mechanical ventilation as well as reduced mortality. The algorithm provides a systematic plan to organize patient care so that the most urgently needed procedures are not delayed or overlooked.

Algorithms↗

PubMedDate not supplied

Comparison of sevral wild-type influenza viruses in the ferret tracheal organ culture system.

Several strains of wild-type influenza A virus were studied in the ferret tracheal organ culture system. Ciliary activity and viral replication were measured. Ciliary activity was reduced more rapidly by A/Hong Kong/45/68 (H3N2) (A/HK) and A/Victoria/3/75 (H3N2) (A/Vic) than by A/New Jersey/8/76 (Hsw1N1) (A/NJ), A/Scotland/840/74(3HN2) (A/Scot), or A/USSR/90/77 (H1N1) (A/USSR). A/HK, A/Vic, and A/Scot produced titers of virus higher than A/USSR or A/NJ during the first three days after infection. Differences in effects of the five viruses on cilia were not related to history of egg passage. The two strains that destroyed ciliary activity rapidly had caused excess mortality in the United States, whereas the three that destroyed ciliary activity more slowly had not. A relationship may exist between the properties contributing to virulence in humans and the destruction of ciliary activity in vitro in this culture system.

Animals↗