The influence of inspired oxygen on the oxygen uptake response to ramp exercise

The relation between and work rate (WR) was examined in seven male subjects who performed ramp (1 W·3 s^–1) two-legged cycle ergometry to exhaustion while inspiring either hypoxic (12% O₂), normoxic (21% O₂), or hyperoxic (40% O₂) air. The anaerobic threshold was estimated from respiratory gas exchange data and is thus referred to as the respiratory gas exchange threshold (RGET). Prior to the RGET, the was greater under normoxic [mean (SD); 10. 19(1.04) ml O₂·min^–1·W^–1] and hyperoxic [10.44 (0.72)] conditions compared with hypoxia [9.34 (0.89)]. Above the RGET, the for hypoxia [8.91 (0.63)], normoxia [10.40 (0.77)], and hyperoxia [11.08 (0.48)] were all significantly different from each other. These data indicated that for two-legged, cycle, ramp ergometry in normoxia below the RGET, both the and response time was constant. Above the RGET, the normoxic response was the net result of a declining and a longer response time to the unsteady state character of a ramp exercise protocol.     

The use of natural interferon alpha conjugated to a monoclonal antibody anti mammary epithelial mucin (Mc5) for the treatment of human breast cancer xenografts

Summary An immunoconjugate composed of natural interferon (nIFN) bound in a noncleavable fashion to a monoclonal antibody (MoAb) recognizing a breast epithelial membrane mucin (Mc5) was used to treat xenografts of a human mammary carcinoma cell line (MCF-7) growing in nude mice. The immunoconjugate (nIFN/Mc5) was administered as 20 intralesional (i.l.) injections to 1 of 2 xenografts in each animal. It was found that nIFN/Mc5 produced a significant enhancement of the growth inhibitory actions of nIFN on the injected tumors. Further enhancement was obtained when nIFN or nIFN together with Mc5 (at a dose 10 times larger than that present in nIFN/Mc5) were added to the immunoconjugate. Biodistribution experiments showed that the uptake of¹²⁵I-nIFN/Mc5 by the tumors was greater and its elimination slower than for¹²⁵I-nIFN alone or conjugated to irrelevant mouse IgG₁. In addition, the immunoconjugate up-regulated the antigenic expression of a breast epithelial membrane mucin by the carcinoma cells, an up-regulation which was not significantly different from that produced by nIFN alone. The contralateral noninjected tumors exposed to systemic levels of the immunoconjugate showed an enhancement of antitumor effects, but to a lesser extent than the injected tumors. These findings suggest that the enhancement of the growth inhibitory action of the immunoconjugate was related to the specific binding of Mc5 which targeted the IFN to the carcinoma cells and impeded its elimination. It is likely that the targeting was favored by the IFN-mediated up-regulation of antigenic expression by the carcinoma cells, thereby producing a cascade of interrelated effects. The results of this study point out the feasibility and potential usefulness of IFN treatment by means of immunoconjugates as well as the worth of pursuing and improving this form of therapy.     

Informed consent, parental awareness, and reasons for participating in a randomised controlled study

BACKGROUND: The informed consent procedure plays a central role in randomised controlled trials but has only been explored in a few studies on children. AIM: To assess the quality of the informed consent process in a paediatric setting. METHODS: A questionnaire was sent to parents who volunteered their child (230 children) for a randomised, double blind, placebo controlled trial of ibuprofen syrup to prevent recurrent febrile seizures. RESULTS: 181 (79%) parents responded. On average, 73% of parents were aware of the major study characteristics. A few had difficulty understanding the information provided. Major factors in parents granting approval were the contribution to clinical science (51%) and benefit to the child (32%). Sociodemographic status did not influence initial participation but west European origin of the father was associated with willingness to participate in future trials. 89% of participants felt positive about the informed consent procedure; however, 25% stated that they felt obliged to participate. Although their reasons for granting approval and their evaluation of the informed consent procedure did not differ, relatively more were hesitant about participating in future. Parents appreciated the investigator being on call 24 hours a day (38%) and the extra medical care and information provided (37%) as advantages of participation. Disadvantages were mainly the time consuming aspects and the work involved (23%). CONCLUSIONS: Parents' understanding of trial characteristics might be improved by designing less difficult informed consent forms and by the investigator giving extra attention and information to non-west European parents. Adequate measures should be taken to avoid parents feeling obliged to participate, rather than giving true informed consent.     

Rearrangement of the T cell receptor gamma-chain gene in childhood acute lymphoblastic leukemia

We analyzed rearrangements of the T cell receptor gamma-chain (T gamma) gene as well as rearrangements of the T cell receptor beta-chain (T beta) gene and immunoglobulin heavy-chain (IgH) gene in 68 children with acute lymphoblastic leukemia (ALL). All 15 patients with T cell ALL showed rearrangements of both T beta and T gamma genes. Twenty-four of 53 non-T, non-B ALL patients (45%) showed T gamma gene rearrangements and only 14 of these also showed T beta gene rearrangements. Only a single patient rearranged the T beta gene in the absence of T gamma gene rearrangement. The rearrangement patterns of the T gamma gene in non-T, non-B ALL were quite different from those observed in T cell ALL, as 20 of 23 patients retained at least one germline band of the T gamma gene. In contrast, all T cell ALL patients showed no retention of germline bands. These data indicate that rearrangement of the T gamma gene is not specific for T cell ALL. Further, the results also suggest that T gamma gene rearrangement precedes T beta gene rearrangement. The combined analysis of rearrangement patterns of IgH, T beta, and T gamma genes provides new criteria for defining the cellular origin of leukemic cells and for further delineation of leukemia cell heterogeneity.     

Synthetic cannabinoid “Black Mamba” infidelity in patients presenting for emergency stabilization in Colorado: a P SCAN Cohort

Background: Use of new psychoactive substances (NPS) has increased over the last decade. During this period, variability of both clinical presentations and chemical compositions of these compounds has increased. Synthetic cannabinoids (SCs) are the most commonly used NPS and there are more than 100 documented unique molecules in this class. “Black Mamba”, often associated to ADB-FUBINACA, is the most commonly used SC in Colorado. It has been linked to kidney injury, myocardial toxicity, seizures, and death.

Objectives: We aim to identify the chemical constituents and quantification of eight cases of reported “Black Mamba” use in order to further understand the clinical variability in patients presenting for emergency stabilization.

Methods: We report data from eight cases of reported “Black Mamba” use prospectively captured through the Colorado site of the Psychoactive Surveilance Consortium and Analysis Network (P SCAN). P SCAN is a geographically representative group of academic hospitals that capture clinical presentation, outcome, and biologic samples from patients that present for emergency stabilization following NPS use. Serum and urine samples were analyzed and quantified by liquid chromatography-quadrupole time-of-flight mass spectrometry after a qualitative screen for over 600 unique NPS compounds.

Results: In the reported eight cases, the median age was 28 years old. There were four male and four females. Four patients had agitation/delirium and four patients had chest pain. Normal saline, benzodiazepines and ondansetron were the common treatment provided in the emergency department (ED). Two patients were discharged from the ED and six patients being admitted for emergency observation with a median length of stay (LOS) of six hours. No deaths were reported. Confirmatory testing revealed that only five patients (62.5%) had SCs found in blood or urine samples. Cocaine, NRG-3, 3-methoxyphencyclidine hydrochloride (MeO-PCP), and methamfetamine were identified in other presentations.

Conclusions: The wide range of clinical presentations from “Black Mamba” use may be explained by the wide variability of chemical constituents found by laboratory analysis.     

Simultaneous analysis of 29 synthetic cannabinoids and metabolites,amphetamines, and cannabinoids in human whole blood by liquid chromatography–tandem mass spectrometry – A New Zealand perspective of use in 2018

We describe the validation of a method for the simultaneous analysis of 29 synthetic cannabinoids (SCs) and metabolites, 4 amphetamines, and 2 cannabinoids in human whole blood. This method enables one analysis to cover what previously required multiple analyses for these classic and novel drugs‐of‐abuse with diverse physicochemical properties. The scope of targeted analytes was based on the most prevalent drugs‐of‐abuse and SCs encountered at the New Zealand border in 2017 and included parent compounds and metabolites belonging to the indole and indazole carboxamide, quinolinyl indole carboxylate, and naphthoylindole classifications. Samples were prepared by supported‐liquid‐extraction (SLE) followed by liquid chromatography?tandem mass spectrometry (LC?MS/MS) analysis with positive electrospray ionization (ESI). The method was validated with respect to selectivity, matrix effects, process efficiency, sensitivity, repeatability, extract stability, and carryover for qualitative confirmation. Linearity as well as accuracy and precision data at target decision concentrations were also evaluated. The limits of detection and confirmation ranged from 0.1 to 6.0 ng/mL and 1.0 to 6.0 ng/mL, respectively. The described method was successfully applied to the analysis of 564 ante‐ and post‐mortem blood samples in 2018. There were 132 cases (23%) with positive findings of at least one SC, with the five most commonly detected SCs being AMB‐FUBINACA and/or acid (61%), 5F‐ADB and/or acid (40%), ADB‐FUBINACA (11%), 5F‐MDMB‐PICA acid (6%), and MDMB‐FUBINACA acid (6%). The results also demonstrate the predominant presence of metabolites at higher levels than the unchanged parent SCs in blood, highlighting the need to maintain forensic screening methods capable of the simultaneous detection of both parent compounds and metabolites.     

The chemistry and pharmacology of putative synthetic cannabinoid receptor agonist (SCRA) new psychoactive substances (NPS) 5F‐PY‐PICA, 5F‐PY‐PINACA,and their analogs

5F‐PY‐PICA and 5F‐PY‐PINACA are pyrrolidinyl 1‐(5‐fluoropentyl)ind (az)ole‐3‐carboxamides identified in 2015 as putative synthetic cannabinoid receptor agonist (SCRA) new psychoactive substances (NPS). 5F‐PY‐PICA, 5F‐PY‐PINACA, and analogs featuring variation of the 1‐alkyl substituent or contraction, expansion, or scission of the pyrrolidine ring were synthesized and characterized by nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography–quadrupole time‐of‐flight–mass spectrometry (LC–QTOF–MS). In competitive binding experiments against HEK293 cells expressing human cannabinoid receptor type 1 (hCB₁) or type 2 (hCB₂), all analogs showed minimal affinity for CB₁ (pK_i < 5), although several demonstrated moderate CB₂ binding (pK_i 5.45–6.99). In fluorescence‐based membrane potential assays using AtT20‐hCB₁ or ‐hCB₂ cells, none of the compounds (at 10 μM) produced an effect >50% of the classical cannabinoid agonist CP55,940 (at 1 μM) at hCB₁, although several showed slightly higher relative efficacy at hCB₂. Expansion of the pyrrolidine ring of 5F‐PY‐PICA to an azepane ( 8 ) conferred the greatest hCB₂ affinity (pK_i 6.99) and activity (pEC₅₀ 7.54, E_max 72%) within the series. Unlike other SCRA NPS evaluated in vivo using radio biotelemetry, 5F‐PY‐PICA and 5F‐PY‐PINACA did not produce cannabimimetic effects (hypothermia, bradycardia) in mice at doses up to 10 mg/kg.     

The chemistry and pharmacology of synthetic cannabinoid SDB‐006 and its regioisomeric fluorinated and methoxylated analogs

Synthetic cannabinoids are the largest and most structurally diverse class of new psychoactive substances, with manufacturers often using isomerism to evade detection and circumvent legal restriction. The regioisomeric methoxy‐ and fluorine‐substituted analogs of SDB‐006 (N‐benzyl‐1‐pentyl‐1H‐indole‐3‐carboxamide) were synthesized and could not be differentiated by gas chromatography–mass spectrometry (GC–MS), but were distinguishable by liquid chromatography–quadrupole time‐of‐flight–MS (LC–QTOF–MS). In a fluorescence‐based plate reader membrane potential assay, SDB‐006 acted as a potent agonist at human cannabinoid receptors (CB₁ EC₅₀ = 19 nM). All methoxy‐ and fluorine‐substituted analogs showed reduced potency compared to SDB‐006, although the 2‐fluorinated analog (EC₅₀ = 166 nM) was comparable to known synthetic cannabinoid RCS‐4 (EC₅₀ = 146 nM). Using biotelemetry in rats, SDB‐006 and RCS‐4 evoked comparable reduction in body temperature (~0.7°C at a dose of 10 mg/kg), suggesting lower potency than the recent synthetic cannabinoid AB‐CHMINACA (>2°C, 3 mg/kg).