Biomedical subjects

A Griffen

Publications and source records attributed to A Griffen.

4 recordsLinked to original sources

PubMed2001

Combined use of growth rate correlated and growth rate independent promoters for recombinant glucoamylase production in Fusarium venenatum.

Fusarium venenatum JeRS 325, a strain which produces recombinant glucoamylase under control of a growth rate independent promoter was transformed with a plasmid carrying the Aspergillus niger glucoamylase gene under control of its own growth rate correlated promoter. Some disruption of the original recombinant genes occurred and at pH 5.8 the double transformant did not produce as much glucoamylase as JeRS 325 in batch culture. However, the double transformant still produced as much glucoamylase as JeRS 325 in fed-batch cultures, illustrating the potential for the combined use of growth rate independent and dependent promoters to improve production of recombinant proteins in fed-batch culture systems.

Aspergillus niger↗

PubMed1999

High throughput detection of retrovirus-associated reverse transcriptase using an improved fluorescent product enhanced reverse transcriptase assay and its comparison to conventional detection methods.

The development and application of a novel, sensitive TaqMan fluorescent probe-based product enhanced RT test (F-PERT) for the detection of retrovirus are described. The assay allows discrimination between the amplification signals generated by genuine positive signals that result from retroviral RT activity and the RT-like activity from DNA polymerases. The RT-like activity from DNA polymerases was suppressed by the addition of activated calf-thymus DNA with no reduction in the RT activity. A linear relationship between threshold cycle (C(T)) and the number of virus particles was demonstrated, allowing quantification of retroviruses in unknown samples. The F-PERT assay was able to detect a wide range of retroviral RT activities, including that from porcine endogenous retrovirus (PoERV), murine leukaemia virus (MLV), simian foamy virus (SFV), simian immunodeficiency virus (SIVmac) and squirrel monkey retrovirus (SMRV). The detection limit of SMRV, MLV and PoERV was approximately 100 virion particles and the test was able to detect at least 10(2) molecules of purified RT enzyme. RT activity was not detected in cellular lysates and supernatants from MRC-5, BT, VERO, or Raji cells, whereas RT activity was detected in C1271, Mus dunni, K-Balb, BHK-21, CHO-K1, SP2/0-Ag14 and NSO cell supernatants. RT activity was also detected in the Spodoptera cell line Sf9.

Animals↗

PubMed1981

Glucagon structure-function relationships using isolated rat hepatocytes.

The ability of glucagon and several of its semi-synthetic analogues to stimulate glucose production in isolated rat hepatocytes was measured and compared for relative potencies. The order of decreasing biological activities of glucagon in this assay was as follows: glucagon greater than [HArg12]-glucagon greater than [des-Asn28, Thr29][homoserinehydrazide27]-glucagon approx. equal to [des-His1]-glucagon greater than [des-Asn28, Thr29][homoserinelactone27]-glucagon greater than [des-Asn28, Thr29]-[n-butylhomoserineamide27]-glucagon greater than glucagon1-21. Qualitatively, these results are similar to those obtained previously in the hepatic plasma membrane adenylate cyclase assay. Minor exceptions were noted for the hydrazide derivative and the partial agonist [des-His1]-glucagon, both of which were slightly more potent relative to glucagon in the glycogenolytic assay than in the adenylate cyclase assay. The assay provides important insight into glucagon structure-function relationships.

Amino Acid Sequence↗

PubMedDate not supplied

Conscious sedation experiences in graduate pediatric dentistry programs.

PURPOSE: Conscious sedation is a behavior modification adjunct taught in all postgraduate pediatric dental residency programs. It has been a decade since the last survey was done specifically related to didactic and clinical aspects of conscious sedation in postgraduate pediatric dental programs. The aim of the study was to determine the clinical and didactic experiences associated with conscious sedation in these programs and to compare some of the findings to those collected a decade ago. METHODS: A 31-item survey similar to that of a decade ago was constructed and sent to all pediatric dentistry program directors of accredited postgraduate and residency programs in the United States. The items covered several didactics including didactic topics, sedative agents, monitoring, and emergency policy among others. A follow-up mailing was done involving those who had not responded 6 weeks following the initial mailing. RESULTS: Fifty-four of 58 (93%) program directors returned the 31-item survey. The following are highlighted findings. Conscious sedation among residency programs was achieved most commonly with a combination of sedative agents used with N2O. Midazolam was more popular than chloral hydrate. The oral route was the predominant route of administration. More lecture hours were spent on conscious sedation than 10 years ago. The pre-cordial stethoscope, pulse oximeter, and blood pressure cuff were the most commonly used monitors. Sedative agent and anticipated depth of sedation were the factors most often considered in choosing monitors used during the sedation of a patient. The capnograph was being used more frequently than it was 10 years ago. Programs did not report an increase in sedation emergencies but practiced emergency drills more often and had increased numbers of individuals certified in Advanced Cardiac Life Support (ACLS) or Pediatric Advanced Life Support (PALS). The percent of the total patient population which required sedation is about 1-20%, with most directors reporting an increase in the numbers of sedations done in the past few years. CONCLUSIONS: While many factors remained unchanged or slightly modified when compared to the survey done a decade ago, the results of this study suggest that there has been significant changes in several key factors including the most frequently used sedative (i.e., midazolam) and increased preparation in the area of emergency preparedness.

Administration, Oral↗