Changes in the prevalence of asthma and related risk factors in adolescents: Three surveys between 1994 and 2015.

METHODS: This study assesses the temporal trend of current asthma symptoms prevalence and associated factors in Chilean adolescents from South-Santiago, considering surveys performed in 1994, 2002 and 2015. RESULTS: The prevalence of current asthma symptoms showed a trend to increase from 11.1% in 1994 to 13.4% in 2015 (p<0.001); physician-diagnosed asthma increased from 11.5% to 13.8%, (p<0.001) whereas severe asthma and asthma with exercise decreased (p<0.001). Female adolescents had a higher prevalence of current asthma in the three surveys (p<0.001), and was a risk factor for asthma in the three surveys. In 2002, frequent consumption of meat and potatoes were associated with current asthma while frequent vigorous exercise was protective. Frequent exercise and parental tobacco smoking were risk for asthma in 2015 (p<0.001). Current active tobacco smoking showed a trend to increase reaching a prevalence of 28.9% in 2015 (p<0.001). There was a consistently low proportion of adolescents with current wheezing and asthma diagnosis (32.1% in 2015) and 37.6% of them had no asthma treatment. CONCLUSION: The prevalence of current asthma in adolescents from the studied area would be still increasing. As in other studies, female adolescents had a higher prevalence of current asthma. Current active tobacco smoking has strikingly increased in the studied children while indoor passive tobacco exposure remains inadmissibly high. Our findings suggest that asthma in children is underdiagnosed and undertreated. More attention should be given to female gender, tobacco exposure, air pollution and local diagnostic preferences when studying and interpreting trends of asthma prevalence in adolescents from developing localities.

High-throughput, non-invasive prenatal testing for fetal Rhesus D genotype to guide antenatal prophylaxis with anti-D immunoglobulin: a cost-effectiveness analysis.

OBJECTIVE: To evaluate the cost-effectiveness of high-throughput, non-invasive prenatal testing (HT-NIPT) for fetal Rhesus D (RhD) genotype to guide antenatal prophylaxis with anti-D immunoglobulin compared with routine antenatal anti-D immunoglobulin prophylaxis (RAADP). DESIGN: Cost-effectiveness decision-analytic modelling. SETTING: Primary care. PARTICIPANTS: A simulated population of 100 000 RhD-negative women not known to be sensitised to the RhD antigen. METHODS: A decision tree model was used to characterise the antenatal care pathway in England and the long-term consequences of sensitisation events. The diagnostic accuracy of HT-NIPT was derived from a systematic review and bivariate meta-analysis; estimates of other inputs were derived from relevant literature sources and databases. Women in whom the HT-NIPT was positive or inconclusive continued to receive RAADP, whereas women with a negative result received none. Five alternative strategies in which the use of HT-NIPT may affect the existing postpartum care pathway were considered. MAIN OUTCOME MEASURES: Costs expressed in 2015GBP and impact on health outcomes expressed in terms of quality-adjusted life-years over a lifetime. RESULTS: The results suggested that HT-NIPT appears cost saving but also less effective than current practice, irrespective of the postpartum strategy evaluated. A postpartum strategy in which inconclusive test results are distinguished from positive results performed best. HT-NIPT is only cost-effective when the overall test cost is £26.60 or less. CONCLUSIONS: HT-NIPT would reduce unnecessary treatment with routine anti-D immunoglobulin and is cost saving when compared with current practice. The extent of any savings and cost-effectiveness is sensitive to the overall test cost. TWEETABLE ABSTRACT: HT-NIPT is cost saving compared with providing anti-D to all RhD-negative pregnant women.

Genetic variation in caveolin-1 correlates with long-term pancreas transplant function.

Pancreas transplantation is a successful treatment for a selected group of people with type 1 diabetes. Continued insulin production can decrease over time and identifying predictors of long-term graft function is key to improving survival. The aim of this study was to screen subjects for variation in the Caveolin-1 gene (Cav1), previously shown to correlate with long-term kidney transplant function. We genotyped 435 pancreas transplant donors and 431 recipients who had undergone pancreas transplantation at the Oxford Transplant Centre, UK, for all known common variation in Cav1. Death-censored cumulative events were analyzed using Kaplan-Meier and Cox regression. Unlike kidney transplantation, the rs4730751 variant in our pancreas donors or transplant recipients did not correlate with long-term graft function (p = 0.331-0.905). Presence of rs3801995 TT genotype (p = 0.009) and rs9920 CC/CT genotype (p = 0.010) in our donors did however correlate with reduced long-term graft survival. Multivariate Cox regression (adjusted for donor and recipient transplant factors) confirmed the association of rs3801995 (p = 0.009, HR = 1.83;[95% CI = 1.16-2.89]) and rs9920 (p = 0.037, HR = 1.63; [95% CI = 1.03-2.73]) with long-term graft function. This is the first study to provide evidence that donor Cav1 genotype correlates with long-term pancreas graft function. Screening Cav1 in other datasets is required to confirm these pilot results.

The genome of the simian and human malaria parasite Plasmodium knowlesi.

Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome and other sequenced Plasmodium genomes. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.

Differential pulse oximetry readings between ethnic groups and delayed transfer to intensive care units.

BACKGROUND: Pulse oximeters are widely used to monitor blood oxygen saturations, although concerns exist that they are less accurate in individuals with pigmented skin. AIMS: This study aimed to determine if patients with pigmented skin were more severely unwell at the period of transfer to intensive care units (ICUs) than individuals with White skin. METHODS: Using data from a large teaching hospital, measures of clinical severity at the time of transfer of patients with COVID-19 infection to ICUs were assessed, and how this varied by ethnic group. RESULTS: Data were available on 748 adults. Median pulse oximetry demonstrated similar oxygen saturations at the time of transfer to ICUs (Kruskal-Wallis test, P = 0.51), although median oxygen saturation measurements from arterial blood gases at this time demonstrated lower oxygen saturations in patients classified as Indian/Pakistani ethnicity (91.6%) and Black/Mixed ethnicity (93.0%), compared to those classified as a White ethnicity (94.4%, Kruskal-Wallis test, P = 0.005). There were significant differences in mean respiratory rates in these patients (P < 0.0001), ranging from 26 breaths/min in individuals with White ethnicity to 30 breaths/min for those classified as Indian/Pakistani ethnicity and 31 for those who were classified as Black/Mixed ethnicity. CONCLUSIONS: These data are consistent with the hypothesis that differential measurement error for pulse oximeter readings negatively impact on the escalation of clinical care in individuals from other than White ethnic groups. This has implications for healthcare in Africa and South-East Asia and may contribute to differences in health outcomes across ethnic groups globally.

Synthesis of CDE molecular fragments related to sendanin mediated by titanocene(III).

A practical, brief, and diastereoselective synthesis of limonoid CDE fragments from a readily available starting material is described. The key step was the titanocene(III)-promoted cyclization of unsaturated epoxylactones, readily prepared from α-cyclocitral. In this way, we confirm the viability of our procedure for the synthesis of a limonoid model with different functionalization patterns. We also report the antifeedant activity of epoxylactones 18 and 19, which show significant antifeedant activity against Spodoptera littoralis and Spodoptera frugiperda, two insect species with different feeding ecologies.

Antibacterial compounds from the mushroom Ganoderma colossum from Nigeria.

Three colossolactones (colossolactone E, colossolactone B and 23-hydroxycolossolactone E) were isolated and characterized from an n-hexane:dichloromethane (2:7) extract of Ganoderma colossum using chromatographic techniques. The antimicrobial activity of the three compounds was then tested against Gram-positive and Gram-negative bacteria. The activity was evaluated by the thin-layer chromatography agar overlay method. The results showed that colossolactone E and 23-hydroxycolossolactone E were active against Bacillus subtilis and Pseudomonas syringae. Colossolactone B was not active against the bacteria. Their structures were elucidated by spectroscopic methods. Potency of the compounds against bacteria tested supports the use of this mushroom in therapeutic medicine.

Patient need at the heart of workforce planning: the use of supply and demand analysis in a large teaching hospital's acute medical unit.

Timely medical assessment is integral to the safety and quality of healthcare delivery in acute medicine. Medical staff are an expensive resource. This study aimed to develop a modelling system that facilitated efficient workforce planning according to patient need on the acute medical unit. A realistic 24-hour 'supply' of junior doctors was calculated by adjusting the theoretical numbers on the rota for leave allowances, natural breaks and other ward duties by a combination of direct observation of working practice and junior doctor interviews. 'Demand' was analysed using detailed admission data. Supply and demand were then integrated with data from a survey of the time spent on the process of clerking and assessment of medical admissions. A robust modelling system that predicted the number of unclerked patients was developed. The utility of the model was assessed by demonstrating the impact of a regulation-compliant redesign of the rota using existing staff and by predicting the most efficient use of an additional shift. This simple modelling system has the potential to enhance quality of care and efficiency by linking workforce planning to patient need.

Inspired by vitamin A for anti-ageing: Searching for plant-derived functional retinoid analogues.

Background: Cosmetic treatments that inspire one's appearance to resemble their younger portrait often utilize ingredients that confer acute effects, particularly hydration by creating hydrophobic barriers or transient elevation of barrier water content. But superior therapies successfully promote morphogenesis of the dermal-epidermal junction, inspiring extracellular matrix (ECM) formation. This can be achieved by agonism of the very well-known retinoid nuclear receptors using the endogenous ligand all-trans retinoic acid (tRA), tRA precursors or plant-based functional analogues, with reduced side effects. Aims Materials and Methods: While there are already many promising cosmetic ingredients available from the world's flora, higher potency is favoured, so increasing known candidates is a worth undertaking. Functional analogues of retinoic acid can be identified by culturing fibroblasts with lipophilic candidates from the plant kingdom and assessing gene-arrays. Modern approaches to validating these findings include the coculturing of fibroblasts with keratinocytes as a measure to predict the potential effects of crosstalk. Results and Discussion: In this regard, the most promising plant-derived candidates are of terpene or meroterpene origin, including derivatives of squalene and phytol. Surprisingly pimaric or abietic acids and labdane diterpenes are also noteworthy agonists of the retinoic acid receptor, stimulating collagen expression in dermal fibroblasts. Conclusion: There are numerous derivatives of these terpenes available from the world's flora and research conducted thus far encourages further screening of these chemical candidates.

The open window of susceptibility to infection after acute exercise in healthy young male elite athletes.

The 'open window' theory is characterised by short term suppression of the immune system following an acute bout of endurance exercise. This window of opportunity may allow for an increase in susceptibility to upper respiratory illness (URI). Many studies have indicated a decrease in immune function in response to exercise. However many studies do not indicate changes in immune function past 2 hours after the completion of exercise, consequently failing to determine whether these immune cells numbers, or importantly their function, return to resting levels before the start of another bout of exercise. Ten male 'A' grade cyclists (age 24.2 +/- 5.3 years; body mass 73.8 +/- 6.5 kg; VO2peak 65.9 +/- 7.1 mL x kg(-1) x min(-1)) exercised for two hours at 90% of their second ventilatory threshold. Blood samples were collected pre-, immediately post-, 2 hours, 4 hours, 6 hours, 8 hours, and 24 hours post-exercise. Immune variables examined included total leukocyte counts, neutrophil function (oxidative burst and phagocytic function), lymphocyte subset counts (CD4+, CD8+, and CD16+/56+), natural killer cell activity (NKCA), and NK phenotypes (CD56dimCD16+, and CD56(bright)CD16-). There was a significant increase in total lymphocyte numbers from pre-, to immediately post-exercise (p < 0.01), followed by a significant decrease at 2 hours post-exercise (p < 0.001). CD4+ T-cell counts significantly increased from pre-exercise, to 4 hours post- (p < 0.05), and 6 hours post-exercise (p < 0.01). However NK (CD16+/56+) cell numbers decreased significantly from pre-exercise to 4 h post-exercise (p < 0.05), to 6 h post-exercise (p < 0.05), and to 8 h post-exercise (p < 0.01O). In contrast, CD56(bright)CD16- NK cell counts significantly increased from pre-exercise to immediately post-exercise (p < 0.01). Neutrophil oxidative burst activity did not significantly change in response to exercise, while neutrophil cell counts significantly increased from pre-exercise, to immediately postexercise (p < 0.05), and 2 hours post-exercise (p < 0.01), and remained significantly above pre-exercise levels to 8 hours post-exercise (p < 0.01). Neutrophil phagocytic function significantly decreased from 2 hours post-exercise, to 6 hours post- (p < 0.05), and 24 hours post-exercise (p < 0.05). Finally, eosinophil cell counts significantly increased from 2 hours post to 6 hours post- (p < 0.05), and 8 hours post-exercise (p < 0.05). This is the first study to show changes in immunological variables up to 8 hours post-exercise, including significant NK cell suppression, NK cell phenotype changes, a significant increase in total lymphocyte counts, and a significant increase in eosinophil cell counts all at 8 hours post-exercise. Suppression of total lymphocyte counts, NK cell counts and neutrophil phagocytic function following exercise may be important in the increased rate of URI in response to regular intense endurance training.

Teaching airway management to novices: a simulator manikin study comparing the 'sniffing position' and 'win with the chin' analogies.

BACKGROUND: The 'sniffing position' is widely promoted for teaching airway positioning before intubation, but whether this analogy results in novices placing the head and neck appropriately has not been evaluated. We compared performance following the sniffing position instructions with an alternate analogy, 'win with the chin'. We also compared performance following simple anatomic instructions and no instructions. METHODS: A randomized controlled study of medical students and PGY1 registrars in Surgery and Internal Medicine was performed. Subjects independently positioned a simulator manikin head and neck based upon their understanding of four written instructions in random order: (i) the 'sniffing position'; (ii) the 'win with the chin' analogy, (iii) anatomic instructions; and (iv) no instructions (control). Digital photographs following each instruction were analysed by two airway experts for (i) adequacy of overall positioning and (ii) the three components of airway positioning. RESULTS: Eighty-one volunteers participated. The positioning was adequate most often (43.2%) following the 'win with the chin' analogy when compared with the other instructions (37.0% anatomic instructions; 19.8% control; 14.8% 'sniffing position' analogy). Positioning following the 'sniffing position' instructions was not different from no instruction (P=0.53). The 'win with the chin' and anatomic instructions were significantly better than no instructions (P=0.002 and 0.023, respectively). CONCLUSIONS: The 'win with the chin' analogy resulted in adequate airway positioning significantly more often than the 'sniffing position' or control. It also maintained atlanto-occipital extension compared with anatomic instructions. Overall, 'win with the chin' was a superior teaching analogy and could replace the 'sniffing position' analogy.

CD226 Gly307Ser association with multiple autoimmune diseases.

Genome-wide association studies provide insight into multigenic diseases through the identification of susceptibility genes and etiological pathways. In addition, the identification of shared variants among autoimmune disorders provides insight into common disease pathways. We previously reported an association of a nonsynonymous single nucleotide polymorphism (SNP) rs763361/Gly307Ser in the immune response gene CD226 on chromosome 18q22 with type 1 diabetes (T1D) susceptibility. Here, we report efforts toward identifying the causal variant by exonic resequencing and tag SNP mapping of the 18q22 region in both T1D and multiple sclerosis (MS). In addition to the analysis of newly available samples in T1D (2088 cases and 3289 controls) and autoimmune thyroid disease (AITD) (821 cases and 1920 controls), resulting in strong support for the Ser(307) association with T1D (P=3.46 x 10(-9)) and continued potential evidence for AITD (P=0.0345), we provide evidence for association of Gly307Ser with MS (P=4.20 x 10(-4)) and rheumatoid arthritis (RA) (P=0.017). The Ser(307) allele of rs763361 in exon 7 of CD226 predisposes to T1D, MS, and possibly AITD and RA, and based on the tag SNP analysis, could be the causal variant.

Thermoregulation: effects of environmental temperature on turnover of hypothalamic norepinephrine.

The hypothesis that norepinephrine is a transmitter in the temperature regulating center of the hypothalamus is based on observations of changes in the rectal temperatures of animals after injections of norepinephrine into the hypothalamus. By introducing tritiated norepinephrine as a label into the endogenous norepinephrine stores in the brain and then measuring the disappearance of tritiated norepinephrine from discrete areas, one can monitor the activity of norepinephrine-containing neurons in those areas. In the rat exposed to heat, the turnover of endogenous norepinephrine appears to be increased selectively in the hypothalamus, whereas exposure to cold has no effect.

Time-resolved laser-induced desorption spectroscopy (LIDS) for quantified in-situ hydrogen isotope retention measurement and removal from plasma facing materials.

A laboratory scale laser induced thermal desorption spectroscopy system is developed and tested on tungsten-deuterium and titanium-deuterium codeposits, and its feasibility as a hydrogenic inventory measurement diagnostic is demonstrated over a range of retention values from 5 × 1019 m-2 to 7 × 1023 m-2 for absorbed laser power densities as low as 8 MW m-2. Codeposit layer samples are grown by magnetron sputtering and immersed in a weak argon rf plasma. A 1 kW fiber laser (λ = 1100 nm) heats the samples up to a peak surface temperature ranging from 900 to 1500 K using pulse widths of 0.5 and 1 s. Spectral line emission from Balmer series Dα and Hα from thermally desorbed deuterium and hydrogen, as well as line emission from argon, are monitored as a function of time using an optical spectrometer with maximum temporal resolution of 1 ms. To correct for wall recycling and pumping speed, and to accurately measure the time evolution of the laser-induced thermal desorption, the raw Dα signal is deconvolved with the system response function, which is obtained by injecting a short burst of D2 to approximate an impulse. Calibration is done with a standard D2 leak, and laser induced desorption spectroscopy deuterium retention values are found to be in good agreement with companion measurements made using conventional temperature programmed desorption on samples from the same codeposit batch.

Analysis of HLA class II genes in Hashimoto's thyroiditis reveals differences compared to Graves' disease.

Graves' disease (GD) and Hashimoto's thyroiditis (HT) represent the commonest forms of autoimmune thyroid disease (AITD) each presenting with distinct clinical features. Progress has been made in determining association of HLA class II DRB1, DQB1 and DQA1 loci with GD demonstrating a predisposing effect for DR3 (DRB1(*)03-DQB1(*)02-DQA1(*)05) and a protective effect for DR7 (DRB1(*)07-DQB1(*)02-DQA1(*)02). Small data sets have hindered progress in determining HLA class II associations with HT. The aim of this study was to investigate DRB1-DQB1-DQA1 in the largest UK Caucasian HT case control cohort to date comprising 640 HT patients and 621 controls. A strong association between HT and DR4 (DRB1(*)04-DQB1(*)03-DQA1(*)03) was detected (P=6.79 x 10(-7), OR=1.98 (95% CI=1.51-2.59)); however, only borderline association of DR3 was found (P=0.050). Protective effects were also detected for DR13 (DRB1(*)13-DQB1(*)06-DQA1(*)01) (P=0.001, OR=0.61 (95% CI=0.45-0.83)) and DR7 (P=0.013, OR=0.70 (95% CI=0.53-0.93)). Analysis of our unique cohort of subjects with well characterized AITD has demonstrated clear differences in association within the HLA class II region between HT and GD. Although HT and GD share a number of common genetic markers this study supports the suggestion that differences in HLA class II genotype may, in part, contribute to the different immunopathological processes and clinical presentation of these related diseases.

Therapeutic uses of Aloe L. (Asphodelaceae) in southern Africa.

ETHNOPHARMACOLOGICAL RELEVANCE: The African-Arabian succulent genus Aloe L. (Aloaceae/Asphodelaceae) is represented by approximately 120 infrageneric taxa in southern Africa, including A. ferox Mill., a species long used in commercial natural products. AIMS OF THE STUDY: To assess the documented ethnobotanical knowledge and biocultural value of utility in the genus in southern Africa. MATERIALS AND METHODS: A survey of over 350 multidisciplinary publications was undertaken. RESULTS: Local uses for medicine and wellbeing were identified for over half the species of Aloe occurring in the Flora of Southern Africa region. The most frequently cited medicinal uses were the treatment of infections and internal parasites, digestive ailments and injuries. Numerous species were recorded for their social uses, notably as ingredients in tobacco snuff. CONCLUSION: The exceptional infrageneric diversity of Aloe, and extensive therapeutic uses in southern Africa, indicate its cultural importance in the subcontinent. These factors highlight the need for the conservation of the species as well as their potential as a source of natural products.

Depression augments activity-related pain in women but not in men with chronic musculoskeletal conditions.

OBJECTIVES: The primary objective of the present study was to examine the role of sex as a moderator of the relation between depression and activity-related pain. METHODS: The study sample consisted of 83 participants (42 women, 41 men) with musculoskeletal conditions. Participants were asked to lift a series of 18 canisters that varied in weight (2.9 kg, 3.4 kg and 3.9 kg) and distance from the body. Participants were asked to rate their pain while they lifted each canister and estimate the weight of the canisters. RESULTS: Consistent with previous research, the relations among depression, pain intensity and disability were stronger for women than for men. ANOVA revealed that depression was associated with more intense activity-related pain in women only. For both women and men, the intensity of pain increased with each trial, although the weight of the objects lifted remained constant. Neither sex nor depression had an effect on participants' weight estimates. CONCLUSIONS: The present discussion addresses the mechanisms through which depression may differentially affect pain in women and men. It also addresses the potential clinical implications of pain-augmenting effects of depression in women.

ACTIVE - a randomised feasibility trial study protocol of a behavioural intervention to reduce fatigue in women undergoing radiotherapy for early breast cancer: study protocol.

BACKGROUND: Fatigue is rated as the most distressing side effect of radiotherapy treatment for curable breast cancer. About four in ten women treated experience fatigue, which can last for years after treatment. The impact of this debilitating tiredness is loss of independence and impaired physical and mental function. Our study will take a behavioural intervention with demonstrated effect in treating fatigue in a mixed group of chemotherapy patients and adapt it for women undergoing radiotherapy for early breast cancer. The purpose of this trial is to evaluate the feasibility of delivering the intervention in the radiotherapy pathway for patients at a high risk of fatigue and to explore participants' experiences of the trial and intervention. METHODS: A pragmatic single-site non-blinded feasibility trial of a behavioural intervention. Main inclusion criteria are prescription of the UK standard 40 Gy in 15 fractions over 3 weeks of radiotherapy (± tumour bed boost) for early (stage 0-IIIa) breast cancer. The total projected sample size after attrition is 70. A previously developed fatigue risk score tool will be used to predict individual's likelihood of experiencing fatigue. Thirty women predicted to be at a high risk of experiencing significant fatigue will be allocated in the ratio 2:1 to the behavioural intervention or education trial arms, respectively. These feasibility trial participants will be assessed at baseline, after 10 and 15 fractions of radiotherapy and 10 days, 3 weeks and 6 months after radiotherapy. A further 40 women predicted to be at a lower risk of fatigue will join a risk score validation group.Measures to assess feasibility include recruitment, retention and completion rates and variation in implementation of the intervention. Process evaluation with intervention providers and users includes fidelity and adherence checks and qualitative interviews to understand how changes in behaviour are initiated and sustained. DISCUSSION: This feasibility study collates data to both inform the progression to and design of a future definitive trial and to refine the intervention. TRIAL REGISTRATION: ISRCTN 10303368. Registered August 2017 (retrospectively registered); Health and Care Research Wales Clinical Research Portfolio (CRP) registration 31419.

Chronic lymphocytic leukemia cells lack the 185,000-dalton macromolecular insoluble cold globulin present on normal B lymphocytes.

We have recently characterized two lymphocyte-associated membrane proteins which have been termed 225,000-dalton and 185,000-dalton macromolecular insoluble cold globulin (225-MICG and 185-MICG, respectively) to distinguish their major physicochemical properties. These proteins differ antigenically, structurally, and in their cellular distribution. T cells can be distinguished by the synthesis and presence in the plasma membrane of 225-MICG, Null cells by the appearance of 185-MICG, and B cells by the appearance of both 225- and 185-MICG. The characterization of these two proteins in the monoclonal B lymphocytes of chronic lymphocytic leukemia forms the basis of this report. Using immunofluorescent microscopy, we found only 225-MICG on the surface of chronic lymphocytic leukemia (CLL) cells in 15 patients, whereas control B cells from 20 individuals displayed both 225- and 185-MICG. When MICG proteins were isolated and compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, normal B cells showed two stained bands, corresponding to 225- and 185-MICG, whereas the CLL cells demonstrated only the 225-MICG band. Using labeled amino acid incorporation into cellular protein, normal B cells were shown to synthesize 225- and 185-MICG, whereas CLL cells synthesized only 225-MICG, as determined by immune or cold precipitation of labeled cell lysates. When labeled secretions from B cells and CLL cells were analyzed by immune precipitation, 225- and 185-MICG were secreted by B cells, whereas neither protein was secreted by CLL cells. When normal B cells and CLL cells were mixed, incubated, and lysed together, both 225- and 185-MICG were present, thus excluding proteolysis as a cause of the absence of 185-MICG in CLL. The lack of 185-MICG in CLL distinguishes leukemic cells from normal B lymphocytes. Furthermore, the absence of this normal cell surface protein in these leukemic cells suggests a role for 185-MICG in the malignant transformation of lymphocytes.