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Biomedical subjects

T A Butler

Publications and source records attributed to T A Butler.

At least 19 recordsLinked to original sources
PubMed2001

Single-element solution comparisons with a high-performance inductively coupled plasma optical emission spectrometric method.

A solution-based inductively coupled plasma optical emission spectrometric (ICP-OES) method is described for elemental analysis with relative expanded uncertainties on the order of 0.1% relative. The single-element determinations of 64 different elements are presented, with aggregate performance results for the method and parameters for the determination of each element. The performance observed is superior to that previously reported for ICP-OES, resulting from a suite of technical strategies that exploit the strengths of contemporary spectrometers, address measurement and sample handling noise sources, and permit rugged operation with small uncertainty. Taken together, these strategies constitute high-performance ICP-OES.

Journal Article↗
PubMed1998

Abnormalities of the ETV6 gene occur in the majority of patients with aberrations of the short arm of chromosome 12: a combined PCR and Southern blotting analysis.

Involvement of the ETV6 gene, located at 12p13, has been investigated in 20 patients with an abnormality of the short arm of chromosome 12 (abn 12p) detected cytogenetically. Patients in the study had c/pre-B acute lymphoblastic leukemia (ALL) (nine children and three adults), T-ALL (three adults), acute myeloid leukemia (AML) (two adults), biphenotypic acute leukemia (Bip-L) (one adult), myelodysplasia (MDS) (one adult) and chronic myelomonocytic leukemia (CMML) (one child). Abnormalities of 12p comprised deleted (del)(12p) alone (seven cases), add(12p) alone (seven cases), del(12p) and add(12p) (one case) and balanced translocations of 12p to 1p13, 1q31, 10q11, 14q11 and 15q15 (one case of each). A novel, exon-specific RT-PCR assay identified breakpoints in ETV6 in nine of 19 cases, and showed breakpoints in intron 5 (seven cases of children with c-ALL), in intron 4 (in one adult with Bip-L) and in intron 2 (in one adult with AML). RT-PCR for the ETV6/AMLI fusion (tested in 19 cases) was positive using standard primers in five cases (four of which had shown rearrangements in intron 5) and occurred as a variant fusion in a sixth case (also positive for a rearrangement in intron 5) using 3' RACE PCR. Southern blotting confirmed rearrangements in intron 5 in the five cases available for analysis and revealed a rearrangement in intron 5 in one of 10 cases with no evidence of intron 5 involvement by RT-PCR. Rearrangements in intron 5 of ETV6 were found in eight of nine cases of children with c-ALL of which six carried the ETV6/AMLI fusion. Heterozygosity within intron 5 (revealed by the genomic probe B1) was found in seven of 11 cases tested. Deletion of one allele was indicated in three cases with del(12p) and one case with add(12p). This study, using a combination of ETV6 exon-specific RT-PCR, RT-PCR for ETV6/AMLI and Southern blotting has shown that rearrangement and/or deletion of ETV6 may occur in up to 70% of patients with abn 12p. Furthermore, 90% of children in this study with an abn 12p and c-ALL, carried a rearrangement of ETV6 in intron 5.

Adolescent↗
PubMed1993

The angiotensin II antagonist saralasin inhibits ovulation in the perfused rat ovary.

OBJECTIVE: Our null hypothesis was that the angiotensin II antagonist saralasin does not reduce the number of ovulations in the rat ovarian perfusion model. STUDY DESIGN: Ovaries from pregnant mare's serum gonadotropin-stimulated immature rats were perfused with nutrient media to which luteinizing hormone and 3-isobutyl-1-methylxanthine had been added to induce ovulation. Test perfusions were treated with saralasin 1 mumol/L (n = 0.5) and compared with controls (n = 5) with the Student t test. Perfusions with both saralasin and angiotensin II and dose-response evaluations were performed. RESULTS: Saralasin-treated ovulations were 6.6 +/- 1.3 (mean + SEM) compared with 18.6 +/- 3.9, p < 0.02. The effects of saralasin could be reversed with the addition of an equimolar amount of angiotensin II. Dose-response evaluations showed a progressive inhibition of ovulation at 10(-8) to 10(-6) mol/L. CONCLUSION: The angiotensin II antagonist saralasin inhibits ovulation in a dose-dependent fashion; this effect is canceled by the addition of equimolar concentrations of angiotensin II.

Angiotensin II↗
PubMed1991

Inhibition of ovulation in the perfused rat ovary by the synthetic collagenase inhibitor SC 44463.

A new, powerful, synthetic inhibitor of mammalian tissue collagenases and related metalloproteinases is inhibitory to ovulation in perfused rat ovaries. Ovaries of immature rats, primed with 20 IU of eCG, were dissected and perfused with 0.1 micrograms/ml LH and 0.2 mM 3-isobutyl-1-methylxanthine (IBMX) for 20 h. Addition of SC 44463 (N4-hydroxy-N1-[1S [(4-methoxphenyl)methyl]-2-(methylamino)-2-oxoethyl]- 2R-(2-methylpropyl)butane-diamide) at a concentration of 25 nM inhibited ovulation by 55% (9.6 +/- 1.7 ovulations per ovary, mean +/- SEM, compared to a control value of 21.7 +/- 1.7); and 250 nM inhibited ovulation by 75% (5.3 +/- 1.1 ovulations per ovary). We previously showed that the related compound SC 40827 inhibited ovulation by 70% when used at a concentration of 25 microM (Brännström et al., Endocrinology 1988; 122:1715-1721). We now show that SC 44463 is 100, 500, and 75 times more powerful than SC 40827 in blocking ovulation, inhibiting action of ovarian interstitial collagenase, and inhibiting action of the small metalloproteinase of the rat uterus, respectively. SC 44463 also inhibits ovarian type IV collagen-digesting activity 50% at a concentration of 18 nM. Ovulation occurs after 9-12 h of perfusion with LH. Compound SC 44463 (25 nM) showed its full inhibitory capacity when added to the medium as late as 7 h after LH, but there was no significant inhibition when it was added at 9 h. This suggests that the major collagenolytic events occur beyond 7 h after stimulation by LH.

1-Methyl-3-isobutylxanthine↗
PubMed1988

Are routine preoperative laboratory screening tests necessary to evaluate ambulatory surgical patients?

Two hundred twelve consecutive adult patients undergoing a variety of ambulatory surgical procedures were studied prospectively to investigate whether routine preoperative urinalyses, complete blood counts (CBCs), and electrocardiograms (ECGs) were useful in determining the outcomes of their treatments. Urinalyses (U/As) were abnormal in 83 patients (39%); CBCs were abnormal in 19 patients (9%), and ECGs were abnormal in 140 patients (66%). The mean age of the patients was 64 plus or minus 12 years. The majority of patients with abnormalities determined by laboratory tests could have been predicted to have abnormalities on the basis of their histories and physical examinations. In this study, abnormalities indicated by laboratory tests did not influence preoperative cancellations, intraoperative or postoperative complications, or admissions to the hospital from the ambulatory unit after the surgical procedures. We conclude that routine preoperative screening laboratory tests have only a limited value in ambulatory surgical patients and recommend that they be either eliminated or replaced with less costly studies; for example, dipstick urinalyses for urinalyses, spun hematocrits for CBCs, and ECGs should be performed only if indicated by history and physical examination findings or if requested by an anesthesiologist.

Aged↗
PubMed1986

A new osmium-191/iridium-191m radionuclide generator system using activated carbon.

A new osmium-191/iridium-191m (191Os/191mIr) radionuclide generator system has been developed based on the absorption of K2OsCl6 (Os-IV) on 140-230 mesh heat-treated activated carbon. The generator is eluted with pH 2 saline solution containing 0.25 g/l Kl to give 191mIr in good yield. The generator eluent is neutralized to physiologic pH and isotonicity with Tris buffer immediately prior to i.v. injection. No scavenger column is required. As an example, elution of the prototype generator with a 2-ml bolus results in elution of 191mIr in approximately 18% yield with an 191Os breakthrough of only 2 X 10(-4)%/bolus. The prototype generator has consistent performance over a 2-wk period with no change in 191mIr yield or 191Os breakthrough. Loading of up to 1.5 Ci of 191Os results in no observed radiolysis. Continuous elution of this system is also possible with a mean 191mIr yield of 3.7%/ml and a mean 191Os breakthrough of 2 X 10(-5)%/ml at a flow rate of 12 ml/min. This new system represents a readily available source of 191mIr for radioangiography. Adsorbed radiation dose calculations indicate a total-body dose of only 3.9 mrad for a 100 mCi injected bolus.

Adsorption↗
PubMed1985

The development and in-vivo behavior of tin containing radiopharmaceuticals--I. Chemistry, preparation, and biodistribution in small animals.

Tin is an essential ingredient of most technetium-99m radiopharmaceutical preparations but its in-vivo distribution and long-term fate are not well understood. Tin-117m (t1/2 14d; gamma 159 keV, 86%) is an ideal tracer for studying biological behavior of tin compounds as well as for developing clinically-useful radiopharmaceuticals. This work describes the preparation and in-vivo distribution in mice of a number of tin-117m labeled compounds with commonly used ligands. High bone uptake of most compounds studied as well as the unexpectedly high bone uptake of Sn4+-DTPA indicates a high bone affinity of tin bound to chemically diverse ligands. Various compounds show subtle but significant differences in blood clearance, excretion, and soft-tissue uptake. Differences among Sn2+ and Sn4+ compounds with the same ligand are particularly noteworthy. For stannic chelates, higher bone uptake, faster blood clearance, and reduced soft-tissue concentration were observed. It appears that tin compounds bind to bone predominantly through the tin atom and that the differences in biodistribution depend on factors such as the net charge on the complex, the oxidation state of tin, and hydrolytic and kinetic stabilities of the complexes. The results indicate that the favorable half-life and decay characteristics of tin-117m in various stannic compounds, especially stannic-DTPA, make it potentially useful as an agent for skeletal scintigraphy and radiotherapy of bone tumors.

Animals↗
PubMed1983

Potential tissue-imaging agents: 23-(trimethyl [117mSn]stannyl)-24-nor-5 alpha-cholan-3 beta-ol.

Tin-117m-labeled 23-(trimethylstannyl)-24-nor-5 alpha-cholan-3 beta-ol (2) has been prepared by reaction of trimethyl [117mSn]tin lithium with 3 beta-acetoxy-23-bromo-24-nor-5 alpha-cholane (1). Tin-117m (2) shows pronounced adrenal uptake (2.5% injected dose) in female rats 1 day after injection. Furthermore, the adrenal to liver (9.1:1) and adrenal to blood (33.7:1) ratios are high after this period. The absorbed radiation dose values from [117mSn]2 to human organs have also been estimated by using rat tissue distribution and excretion data. [117mSn]2 is the first reported tissue-specific organic radiopharmaceutical labeled with this nuclide and may have potential as an adrenal imaging agent.

Adrenal Glands↗
PubMed1983

Synthesis and evaluation of 24-(isopropyl[75Se]seleno)chol-5-en-3 beta-ol.

Selenium-75-labeled 24-(isopropylseleno)chol-5-en-3 beta-ol (4) has been prepared by reaction of sodium isopropyl-[75Se]selenol [( 75Se]2) with 3 beta-acetoxy-24-bromochol-5-ene (3). This new 75Se-labeled adrenal imaging agent shows pronounced adrenal uptake in rats. The concentration of radioactivity in rat adrenals increased steadily from 1 to 24 h after injection and then decreased slowly over the 21-day period. After 3 days the adrenal/blood and adrenal/liver ratios were 85:1 and 32:1, respectively, which are sufficient for adrenal imaging by single photon techniques. After 6 h the adrenal/blood ratio was 17:1 and the adrenal/liver ratio was 7:1. We propose that these ratios are sufficiently high for positron emission tomography of the adrenals. The absorbed radiation dose values to human organs have been estimated for the 75Se- and 73Se-labeled agent.

Adrenal Glands↗
PubMed1983

Pharmacokinetics of Ip cisplatin in refractory ovarian carcinoma.

Four patients with small residual ovarian carcinoma following treatment with cisplatin, doxorubicin, and cyclophosphamide have subsequently received 57 courses of ip cisplatin. Cisplatin (120-270 mg in 2 L of Ringer's lactate) was administered via Tenckhoff catheter, with a dwell time of 15-20 mins. Courses were given weekly for 12 weeks, with response documented by laparoscopy or laparotomy prior to and following the trial. With a dwell time of 20 mins, 75% +/- 5% (mean +/- SD) of platinum was recovered. With 120 mg of cisplatin and a dwell time of 20 mins, total plasma platinum peaked at 1.23 +/- 0.42 microgram/ml and by 8 hrs decreased to 0.67 +/- 0.12 microgram/ml. Filterable (non-protein-bound) platinum peaked at 0.73 +/- 0.21 microgram/ml and by 8 hrs fell to 0.03 microgram/ml. Excretion rate paralleled the filterable plasma curve, peaking at 40 mins; 30% +/- 7% of absorbed drug was recovered in urine within 24 hrs. Renal clearance of filterable platinum was 106 +/- 20 ml/min. Creatinine clearance was 76 +/- 7 ml/min. Three responses, one complete and two partial, were noted. Zero to two episodes of vomiting occurred in each course. One patient had a creatinine clearance decrease to 40 ml/min, one had two episodes of thrombocytopenia, and one had mild abdominal pain with a cisplatin dose of greater than or equal to 210 mg. No neurotoxicity, catheter infection, or peritonitis was encountered.

Adult↗
PubMed1982

Innovations in atomic absorption spectrophotometry with electrothermal atomization for determining lead in foods.

A simple and rapid method is described for the determination of lead in foods. The samples are digested in HNO3, HF, and HClO4 and then the lead is determined by atomic absorption spectrophotometry using an electrothermal atomizer with the L'vov platform. Interferences and ways to improve the precision and accuracy of the analysis were studied. Matrix modification using 1% ammonium phosphate alleviated most interferences encountered. The precision and accuracy of the method was evaluated using NBS SRM 1570 Spinach and SRM 1566 Oyster Tissue. The values obtained are in good agreement with the certified values.

Electrochemistry↗
PubMed1979

1-aminocyclobutane[11C]carboxylic acid, a potential tumor-seeking agent.

1-Aminocyclobutane[14C]carboxylic acid [C-14) ACBC] was incorporated preferentially by several tumor types in rats and hamsters. The agent was cleared rapidly from rat blood, attaining its maximum tissue concentrations within 30 min after i.v. injection. Carrier ACBC had little effect on the tissue distribution of (C-14) ACBC. This agent showed no affinity for a Staphylococcus aureus abscess in rats. The total excretion was low, 3.6% in 2 hr. (C-11) ACBC was synthesized in amounts up to 415 mCi (55% chemical yield) using our modified Bücherer-Strecker technique. Forty minutes were required for the two-step synthesis and chromatographic purification. ACBC was found to be nontoxic in three animal species. The radiation dose from (C-11) ACBC should be minimal. (C-11) ACBC thus appears to have good potential as a tumor-seeking agent, particularly when used with a positron emission computed tomograph.

Adenocarcinoma↗
PubMed1979

DL-[Carboxyl-11C]tryptophan, a potential agent for pancreatic imaging; production and preclinical investigations.

In animal studies, DL-[carboxyl-14C]tryptophan [DL-Try(C-14)] showed a high specificity for the pancreas, which suggested the potential of DL-[carboxyl-11C]tryptophan [DL-Try(C-11)] for clinical pancreatic inaging. The blood clearance and tissue uptake of the amino acid were very rapid, and no carrier effect was observed through a dose of 5 mg/kg. None of three transplanted hamster pancreatic adenocarcinomas that we studied showed a selective uptake of DL-Try(C-14) by the tumor, and none of the three enzymatic regimens investigated gave significant enhancement of the pancreatic specificity. Commercial L-Try(C-14) gave slightly better pancreatic specificity than the analogous racemic compound but without enough improvement to warrant attempts at optical resolution. DL-Try(C-11) was synthesized in amounts up to 325 mCi using a rapid, high-temperature, high-pressure modification of the Bücherer-Strecker amino acid synthesis. Yields ranged from 30--60%, and a total of 40 min was required for synthesis and chromatographic purification. DL-Try(C-11) thus appears to have significant potential as a clinical pancreas-imaging agent, particularly when used in conjunction with positron computerized transaxial tomography.

Adenocarcinoma↗