The in vitro transformation of thymocytes and lymphocytes from humans, rabbits and guinea-pigs and from thymomas

The response of human, rabbit and guinea-pig thymocytes in culture to blastogenic stimulants such as phytohaemagglutinin (PHA) and staphylococcal filtrate (SF) was usually considerably less than that seen with equivalent numbers of peripheral blood and lymph node lymphocytes.     

Hydrophobic IgG-containing immune complexes in the plasma of autoimmune MRL/lpr mice, lactate dehydrogenase-elevating virus-infected mice, and pigs: association with transforming growth factor-beta and pH-dependent amplification

Persistent infection of mice with lactate dehydrogenase-elevating virus (LDV) is associated with polyclonal B cell activation, autoimmunity, and circulating hydrophobic IgG-containing immune complexes (ICs), which bind to the surfaces of uncoated ELISA plates in the presence of 0.05% Tween 20. We demonstrate here that hydrophobic IgG-containing ICs also appear naturally in the plasma of autoimmune MRL/lpr mice. These and the similar hydrophobic ICs of LDV-infected mice as well as pigs coincide on ELISA plate surfaces with TGF-beta, apparently in the form of an IgG-TGF-beta complex. Circulating hydrophobic IgG-containing ICs are also susceptible to considerable amplification in vitro by exposure to alkaline conditions. By this latter method, the fraction of in vivo hydrophobic IgG, relative to the maximum in vitro chemically inducible IgG, was found to be about 20% in the plasma of LDV-infected mice, 5% in normal mouse plasma, and less than about 2% in pig plasma. These results indicate the potential for both chemically induced and protein-binding contributions to the generation of hydrophobic IgG-containing molecules, and have implications for immunopathological mechanisms in autoimmunity and persistent virus infections.     

Pharyngeal size in snorers, nonsnorers, and patients with obstructive sleep apnea

We measured pharyngeal cross-sectional area and its change with alterations in lung volume in 10 subjects who snored and had obstructive sleep apnea, 6 subjects who snored and did not have obstructive sleep apnea, and 9 subjects who did not snore. Pharyngeal area was measured with use of an acoustic-reflection technique. We found that snorers with and without sleep apnea had a significantly smaller mean (+/- SE) pharyngeal cross-sectional area (4.1 +/- 0.2 and 3.7 +/- 0.9 cm2, respectively) at functional residual capacity than nonsnorers (5.4 +/- 0.5 cm2, P less than 0.025). When lung volume decreased from functional residual capacity to residual volume, both nonsnorers and snorers with sleep apnea had a decrease in pharyngeal area (from 5.4 +/- 0.5 to 4.5 +/- 0.4 cm2 and 4.1 +/- 0.2 to 3.4 +/- 0.2 cm2, respectively), whereas snorers without sleep apnea had no such decrease, suggesting that their pharynxes were less collapsible at low lung volumes. We conclude that snorers with and without sleep apnea have smaller pharyngeal cross-sectional areas than nonsnorers and that snorers with sleep apnea have a further decrease as lung volume falls.     

SKALP/elafin gene polymorphisms are not associated with pustular forms of psoriasis

Psoriasis is a multifactorial skin disease characterised by epidermal abnormalities and infiltration by lymphocytes and polymorphonuclear leukocytes (PMN). Skin-derived antileukoproteinase (SKALP), also known as elafin, is a potent inhibitor of human leukocyte elastase and proteinase 3, two PMN-derived proteinases implicated in tissue destruction and leukocyte migration. We have shown that, at least at the protein level, SKALP is significantly decreased in lesional skin of patients with pustular psoriasis compared with plaque-type psoriasis. This finding raised the possibility that SKALP could be one of the candidate genes for pustular forms of psoriasis. We therefore performed single strand conformation polymorphism (SSCP) analysis on the SKALP gene to screen for mutations/polymorphisms in the exons of 30 patients with plaque-type psoriasis, 15 patients with pustular psoriasis and 48 healthy controls. In exon 1 a polymorphism was detected at position + 43 relative to the translation start site, resulting in a substitution of threonine for alanine in the signal peptide. In the promoter region a dinucleotide repeat polymorphism was identified. Both polymorphisms were not associated with pustular psoriasis, or psoriasis in general. Our data indicate that the decrease in SKALP activity in pustular psoriasis is not caused by mutations in the coding region of the gene, and that there is no allelic association between pustular psoriasis and SKALP gene polymorphisms.     

Semiautomated Quantitation of Carotid Artery Stenosis in Gadolinium-Bolus Magnetic Resonance Angiography

Magnetic resonance angiography (MRA) has become the standard method for evaluation of carotid occlusive disease. Fast imaging methods combined with bolus intravenous injection of gadolinium contrast have improved the quality of these images. Nevertheless, the gold standard for evaluation was based on projection arterial angiography. The properties of these images are rather different. Whereas most previous evaluations of MRA have used visual assessment of images, we evaluate an algorithm in which a computer algorithm plays the primary role in defining arterial lumen margins, hence, disease. The accuracy of this semiautomated algorithm is shown to compare favorably with gold-standard arteriography in a series of 50 patients.     

Functional Analysis of B-L (Ia-Like) Antigen-Bearing Chicken Peripheral Blood Cells

The functional of B-L (Ia-equivalent)-positive (B-L+) adn -negative (B-L-) chicken peripheral blood lymphocytes (PBL) was studied in vitro and in vivo. The PBL were first stained in direct immunofluorescence tests with a fluorescein isothiocyanate-labelled anti-B-L alloantiserum and then separated by means of a fluorescence-activated cell sorter. In agreement with our previous findings, B-L- cells showed functional properties of T lymphocytes, responding to concanavalin A and phytohaemagglutinin-P in vitro and inducing a graft-versus-host (GVH) reaction when injected into allogeneic embryos. Sorted B-L+ gave no responses in any of these assays. Neither B-L+ nor B-L- cells, when tested alone, responded significantly to pokeweed mitogen, but mixtures of the two restored the responsiveness to that of the original unsorted suspension. Of the B-L+ PBL, 10% were T cells, which may account for the low GVH reactivity given by this population.     

Modification of resistance of mice to Naegleria fowleri infections.

Naegleria fowleri, which produces a fatal meningoencephalitis in humans, is also able to produce a progressive and fatal disease in mice. The course of the disease in DUB/ICR mice is dependent upon the infecting dose of organisms, whether administered intraperitoneally (i.p.) or intravenously (i.v.). All of the mice receiving 10(7) trophozoites/mouse i.v. or 4.85 X 10(7) trophozoites/mouse i.p. were killed within 10 days. Escherichia coli O26:B6 lipopolysaccharide, administered at a dose of 1 mg/kg 24 h prior to N. fowleri, afforded some protection for several days after challenge, but by day 8 there was no difference in survival of untreated and endotoxin-treated mice. No significant protection was afforded by a complex of lipid A with concanavalin A (ConA) or bovine serum albumin (BSA) or by dimethylmyristamide-BSA, dimethylmyristamide, BSA, beta-hydroxymyristic acid-ConA, beta-hydroxymyristic acid, ConA, myristic acid-BSA, or myristic acid. Mice surviving primary i.v. or i.p. challenge doses of N. fowleri, 5 X 10(6) and 10(7) trophozoites/mouse, respectively, were highly resistant to rechallenge with an i.v. dose of organisms (5 X 10(6) Naegleria/mouse) that produced uniformly fatal disease in untreated control mice.     

Continuous Glucose Monitoring Use in Clinical Trials for On-Market Diabetes Drugs

To the best of our knowledge, there are no published data on the historical and recent use of CGM in clinical trials of pharmacological agents used in the treatment of diabetes. We analyzed 2,032 clinical trials of 40 antihyperglycemic therapies currently on the market with a study start date between 1 January 2000 and 31 December 2019. According to ClinicalTrials.gov, 119 (5.9%) of these trials used CGM. CGM usage in clinical trials has increased over time, rising from <5% before 2005 to 12.5% in 2019. However, it is still low given its inclusion in the American Diabetes Association’s latest guidelines and known limitations of A1C for assessing ongoing diabetes care.

The availability of reliable continuous glucose monitoring (CGM) systems has proven to be a major innovation in diabetes management and research. Most current CGM systems are approved for 7- to 14-day use and use a wire-tipped glucose oxidase sensor inserted in subcutaneous tissue to monitor glucose concentrations in interstitial fluid. One implanted CGM system is approved for longer-term use (90–180 days); it operates with fluorescence-based technology. CGM sensors record a glucose data point every 1–15 minutes (depending on the system), collecting far more granular data and information on glycemic patterns than self-monitoring of blood glucose (SMBG) alone. Real-time CGM or intermittently scanned CGM systems send data continuously or intermittently to dedicated receivers or smartphones, whereas professional CGM systems provide retrospective data, either blinded or unblinded, for analysis and can be used to identify patterns of hypo- and hyperglycemia. Professional CGM can be helpful to evaluate patients when other CGM systems are not available to the patient or the patient prefers a blinded analysis or a shorter experience with unblinded data.In the 20 years since CGM systems first became available to people with diabetes, technological improvements, particularly pertaining to accuracy and form factor, have made CGM increasingly viable for both patient use and clinical investigation (1,2). Average sensor MARD (mean absolute relative difference; a summary accuracy statistic) has decreased from >20 to <10% (3–10), including two systems that do not require fingerstick calibrations and three that are approved to be used for insulin dosing (11). Concurrently, size, weight, and cost of CGM systems have all decreased, while user-friendliness and convenience have increased (12).To encourage use of CGM-derived data, researchers and clinicians have worked to develop a standard set of glycemic metrics beyond A1C. In 2017, two international groups of leading diabetes clinical and research organizations published consensus definitions for key metrics, including clinically relevant glycemic cut points for hypoglycemia (<70 and <54 mg/dL), hyperglycemia (>180 and >250 mg/dL), and time in range (TIR; 70–180 mg/dL) (13,14).CGM-derived metrics provide far greater precision and granularity than is possible with SMBG or A1C data alone (Table 1), enabling clinicians and investigators to better represent inter- and intraday glycemic differences with metrics such as TIR, glycemic variability, and time in hypoglycemia and hyperglycemia (15). Crucially, CGM also allows for the accurate measurement and detection of nocturnal glycemia (16). The use of these metrics enables a more comprehensive understanding of glycemic management that can facilitate individualized treatment for people with diabetes or prediabetes. Although A1C is a useful estimate of mean glucose over the previous 2–3 months, especially when evaluating population health, it is important to include other glycemic outcomes in clinical trials. Furthermore, there is emerging evidence suggesting that TIR predicts the development of microvascular complications at least as well as A1C (17,18).TABLE 1Benefits of CGM Compared With A1C Alone in Assessing Glycemia

Validation of a brief screening instrument for substance abuse and mental illness in HIV-positive patients

BACKGROUND: Substance abuse (SA) and mental illness (MI) commonly co-occur with HIV infection in the United States and have important implications for clinical management of HIV/AIDS. Yet SA/MI often go untreated due in part to a lack of practical, validated screening tools. SETTING: HIV clinic in academic medical center. METHODS: The 16-item SA/MI Symptoms Screener (SAMISS) targets SA/MI in HIV-positive patients. Consecutive consenting HIV-positive patients completed the SAMISS and then a reference standard diagnostic tool, SCID, the Structured Clinical Interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition). RESULTS: Twenty percent of participants (29/148) had an SA diagnosis and 41% (59/143) had an MI diagnosis in the past year on the SCID; 48% (68/143) had 1 or both. Thirty-seven percent (55/148) screened positive for SA and 69% (99/143) screened positive for MI on the SAMISS. The SAMISS had 86% (95% CI: 68%-96%) sensitivity and 75% (66%-82%) specificity for SA and 95% (86%-99%) sensitivity and 49% (38%-60%) specificity for MI. Patients with SA were likely to show up as false positives for MI and vice versa. CONCLUSION: The SAMISS functioned well as a first-line screening tool for SA/MI in this HIV clinic population. It missed few cases and was easily incorporated into a busy clinical setting. Persons screening positive require a more rigorous confirmatory psychiatric evaluation.