Self-reported beta-lactam allergy in government and private hospitals in Cape Town, South Africa.

BACKGROUND: Up to a quarter of inpatients in high-income countries (HICs) self-report beta-lactam allergy (BLA), which if incorrect,increases the use of alternative antibiotics, worsening individual health outcomes and driving bacterial resistance. In HICs, up to 95% ofself-reported BLAs are incorrect. The epidemiology of BLA in low- and middle-income African countries is unknown. OBJECTIVES: To describe the epidemiology and de-labelling outcomes of self-reported BLA in hospitalised South African (SA) patients. METHODS: Point-prevalence surveys were conducted at seven hospitals (adult, paediatric, government and privately funded, district andtertiary level) in Cape Town, SA, between April 2019 and June 2021. Ward prescription records and in-person interviews were conductedto identify and risk-stratify BLA patients using the validated PEN-FAST tool. De-labelling was attempted at the tertiary allergy clinic atGroote Schuur Hospital. RESULTS: A total of 1 486 hospital inpatients were surveyed (1 166 adults and 320 children). Only 48 patients (3.2%) self-reported a BLA,with a higher rate in private than in government-funded hospitals (6.3% v. 2.8%; p=0.014). Using the PEN-FAST tool, only 10.4% (n=5/48)of self-reported BLA patients were classified as high risk for true penicillin hypersensitivity. Antibiotics were prescribed to 70.8% (n=34/48)of self-reported BLA patients, with 64.7% (n=22/34) receiving a beta-lactam. Despite three attempts to contact patients for de-labelling atthe allergy clinic, only 3/36 underwent in vivo testing, with no positive results, and 1 patient proceeded to a negative oral challenge. CONCLUSION: Unlike HICs, self-reported BLA is low among inpatients in SA. The majority of those who self-reported BLA were low risk fortype 1 hypersensitivity, but outpatient de-labelling efforts were largely unsuccessful.

Seahorse brood pouch morphology and control of male parturition in Hippocampus abdominalis.

INTRODUCTION: Syngnathids (seahorses, pipefishes and seadragons) are among the few vertebrates that display male pregnancy. During seahorse pregnancy, males incubate developing embryos embedded in a placenta within a fleshy brood pouch, before expelling fully developed neonates at parturition. The mechanisms underpinning seahorse parturition are poorly understood. METHODS: We examined the morphology of the brood pouch using microcomputed tomography and histological techniques, in combination with physiological assays, to examine how male pot-bellied seahorses (Hippocampus abdominalis) control labour. In female-pregnant vertebrates, nonapeptide hormones (such as vasopressin- and oxytocin-like hormones) produce contractions of gestational smooth muscle to produce labour. RESULTS: Histological analysis of the seahorse brood pouch reveals only scattered small smooth muscle bundles in the brood pouch, and in-vitro application of isotocin (a teleost nonapeptide hormone) to the brood pouch do not produce measurable muscle contractions. Micro-computed tomography shows differences in size and orientation of the anal fin assembly between male and female pot-bellied seahorses, and histological analysis reveals large skeletal muscle bundles attached to the anal fin bones at the male brood pouch opening. DISCUSSION: We conclude that seahorse parturition may be facilitated by contraction of these muscles, which, in combination with body movements, serves to gape open the pouch and expel the neonates. Future biomechanical studies are needed to test this hypothesis.

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.

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.

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.

[1-11C] DL-valine, a potential pancreas-imaging agent.

There is a great need for a better pancreas-imaging agent. Studies with [1-14C] DL-valine have shown this amino acid to have a high pancreatic specificity in the four animal species examined. The tissue distribution was almost optimal by 30 min after injection, and no carrier effect was observed through a dose of 5 mg/kg. [1-11C] DL-Valine was synthesized in amounts up to 363 mCi using a rapid (T1/2 = 20.4 min for C-11), high-temperature, high-pressure modification of the Bücherer-Strecker amino acid synthesis. Purification was by anion-exchange followed by cation-exchange chromatography. [1-11C] DL-Valine was obtained in a 70% chemical yield with a total synthesis and purification time of 45 min. Studies in animals have demonstrated that it is a potentially useful new agent for clinical pancreatic imaging.

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.

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.

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.

Tumor location with 1-aminocyclopentane [11C] carboxylic acid: preliminary clinical trials with single-photon detection.

High specific activity [11C] Carboxyl-labeled 1-aminocyclopentane-carboxylic acid ([11C] ACPC) was tested as a tumor-scanning agent in thirty-eight patients. This artificial amino acid clears the blood to a level of less than 12% within 45 min; thus, imaging is possible within the useful life of C-11. [11C] ACPC can be produced in amounts adequate for clinical scanning. Doses between 12 and 45 mCi were given by i.v. injection, and scans obtained only in the single-photon mode gave clinical information on the sites of tumors. There was no evidence of any toxic effects from [11C] ACPC, and the radiation doses as extrapolated from animal data are approximately 0.01 rad per mCi for the whole body and less than 0.06 rad per mCi for the pancreas. In all but five of the 38 patients [11C] ACPC scans were compared with those obtained with Ga-67 citrate. There were 19 positive [11C] ACPC scans and 24 positive Ga-67 scans. The results indicate that [11C] ACPC is likely to be of diagnostic value for cancer patients if used in conjunction with positron tomography instrumentation.

Carboxyl-labeled 11C-1-aminocyclopentanecarboxylic acid, a potential agent for cancer detection.

Carboxyl-labeled 11C-1-aminocyclopentanecarboxylic acid (11C-ACPC) has been prepared in multimillicurie amounts. The conversion of H11CN to 11C-ACPC (t1/2 = 20.4 min) was accomplished by a rapid (20-min) two-step high-temperature modification of the Bücherer-Strecker amino acid synthesis technique, which should be applicable at other accelerator installations. Purification was by ion exchange techniques. Animal studies have indicated that 11C-ACPC is a potential tumor-localizing agent for detecting cancer in humans by nuclear medicine scanning techniques.

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.

Compost age and sample storage effects on maturity indicators of biosolids compost.

Compost product safety and quality assurance are required to meet the needs of the horticultural, agricultural, and silvicultural user markets. At present, there exist no industry-wide sampling and testing protocols for compost products, thus limiting the production sector. The objective of this research was to test three methods for determining compost maturity. The study followed the composting process of a locally successful commercial composting operation that had been producing lime-stabilized biosolids compost in the Washington, DC metro region for 12 yr. Change over time in the dependent variables--Dewar flask self-heating capacity, oxygen uptake rate, and cation exchange capacity (CEC)-during a 57-d composting of lime-stabilized biosolids was studied. Because cold storage at 4 degrees C is recommended when compost samples cannot be tested for maturity immediately, cold storage of up to 11 wk was included as a variable. Mathematical models were developed that predict change in the Dewar flask self-heating capacity, oxygen uptake rate, and CEC with composting time and storage at 4 degrees C. The Dewar flask self-heating test was the most useful indicator of compost maturity. This test showed change throughout the 57-d biosolids composting period while oxygen respirometry did not change after 29 d. The CEC was found to increase with age and storage. Storage effects varied for the different tests. Except for Days 1 and 57, composts continued to stabilize during storage. Testing stored composts may produce erroneous results that suggest the compost is mature.

Effect of 5-hydroxytryptamine antibodies on pigment migration in the erythrophores of the fiddler crab, Uca pugilator: further evidence for 5-hydroxytryptamine as a neurotransmitter that stimulates release of red pigment-dispersing hormone.

5-Hydroxytryptamine (5-HT) antibodies inhibit red pigment dispersion in the fiddler crab, Uca pugilator. This observation supports the hypothesis that 5-HT stimulates release of red pigment-dispersing hormone.

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.

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.

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.