Extracorporeal Blood Treatment Using Functional Magnetic Nanoclusters Mitigates Organ Dysfunction of Sepsis in Swine

Mitigating sepsis-induced severe organ dysfunction with magnetic nanoparticles has shown remarkable advances in extracorporeal blood treatment. Nevertheless, treating large septic animals remains challenging due to insufficient magnetic separation at rapid blood flow rates (>6 L h-1 ) and limited incubation time in an extracorporeal circuit. Herein, superparamagnetic nanoclusters (SPNCs) coated with red blood cell (RBC) membranes are developed, which promptly capture and magnetically separate a wide range of pathogens at high blood flow rates in a swine sepsis model. The SPNCs exhibited an ultranarrow size distribution of clustered iron oxide nanocrystals and exceptionally high saturation magnetization (≈ 90 emu g-1 ) close to that of bulk magnetite. It is also revealed that CD47 on the RBCs allows the RBC-SPNCs to remain at a consistent concentration in the blood by evading innate immunity. The uniform size distribution of the RBC-SPNCs greatly enhances their effectiveness in eradicating various pathogenic materials in extracorporeal blood. The use of RBC-SPNCs for extracorporeal treatment of swine infected with multidrug-resistant E. coli is validated and found that severe bacteremic sepsis-induced organ dysfunction is significantly mitigated after 12 h. The findings highlight the potential application of RBC-SPNCs for extracorporeal therapy of severe sepsis in large animal models and potentially humans.

Improve the clinical effective decision of the oral feeding readiness in preterm infants: Revise and validate the TC-POFRAS

BACKGROUND

Currently there is limited information to guide health professionals regarding the optimal time frame to initiate safe and effective oral feedings to preterm infants. The study aims to revise and validate a streamlined version of the Traditional Chinese-Preterm Oral Feeding Readiness Assessment Scale, the TC-POFRAS®, and evaluate its construct validity in the clinical decisions regarding feeding readiness of preterm infants.

METHODS

Eighty-one clinically stable preterm infants were assessed using the TC-POFRAS for oral feeding readiness. Item-total correlation analysis was used to check if any item was inconsistent with the averaged TC-POFRAS scores. Cronbach's α coefficient was used to evaluate the inter-item consistency. Exploratory factor analysis was used to determine the coherence of variables to reorganize assessment domains. The revised version of TC-POFRAS (TC-POFRAS®) was developed and a new cut-off score based on discriminant accuracy was established.

RESULTS

Based on the results from statistical analysis, five items ("lips posture," "tongue posture," "biting reflex," "gag reflex," and "tongue cupping") were deleted from the original TC-POFRAS to form the TC-POFRAS®. The TC-POFRAS®'s global accuracy was 92.1%. The cut-off value of 19 was the one that presented the most optimization of sensitivity based on specificity. The TC-POFRAS® was reconstructed into corrected gestational age and five behavioral domains.

CONCLUSIONS

The TC-POFRAS® is considered a valid, safe, and accurate objective instrument to assist health professionals to initiate oral feeding of preterm infants.

PD-L1 expression, tumor mutational burden, and response to immunotherapy in patients with MET exon 14 altered lung cancers

Background

MET exon 14 alterations are actionable oncogenic drivers. Durable responses to MET inhibitors are observed in patients with advanced MET exon 14-altered lung cancers in prospective trials. In contrast, the activity of immunotherapy, PD-L1 expression and tumor mutational burden (TMB) of these tumors and are not well characterized.

Patients and methods

Patients with MET exon 14-altered lung cancers of any stage treated at two academic institutions were identified. A review of clinicopathologic and molecular features, and an analysis of response to single-agent or combination immune checkpoint inhibition were conducted. PD-L1 immunohistochemistry was carried out and TMB was calculated by estimation from targeted next-generation sequencing panels.

Results

We identified 147 patients with MET exon 14-altered lung cancers. PD-L1 expression of 0%, 1%-49%, and ≥50% were 37%, 22%, and 41%, respectively, in 111 evaluable tumor samples. The median TMB of MET exon 14-altered lung cancers was lower than that of unselected non-small-cell lung cancers (NSCLCs) in both independently evaluated cohorts: 3.8 versus 5.7 mutations/megabase (P < 0.001, n = 78 versus 1769, cohort A), and 7.3 versus 11.8 mutations/megabase (P < 0.001, n = 62 versus 1100, cohort B). There was no association between PD-L1 expression and TMB (Spearman's rho=0.18, P = 0.069). In response-evaluable patients (n = 24), the objective response rate was 17% (95% CI 6% to 36%) and the median progression-free survival was 1.9 months (95% CI 1.7-2.7). Responses were not enriched in tumors with PD-L1 expression ≥50% nor high TMB.

Conclusion

A substantial proportion of MET exon 14-altered lung cancers express PD-L1, but the median TMB is lower compared with unselected NSCLCs. Occasional responses to PD-1 blockade can be achieved, but overall clinical efficacy is modest.

The associations between anthropometric measurements and left ventricular structure and function: the Echo-SOL Study

OBJECTIVE

The objective of this study is to determine associations between anthropometry and echocardiographic measures of cardiac structure and function in Hispanic/Latinos.

METHODS

A total of 1,824 participants from ECHO-SOL were included. We evaluated associations between echocardiographic measures of left ventricular structure and function and anthropometric measures using multivariable-adjusted linear and logistic regression models adjusting for traditional cardiovascular risk factors.

RESULTS

The mean age was 56 ± 0.17 years, 57% were women. The mean body mass index (BMI) was 30 ± 9.4 kg m-2, waist circumference (WC) was 100 ± 18 cm, and waist-to-hip ratio (WHR) was 0.93 ± 0.15. Adjusted analysis showed that 5-unit increment in BMI and 5-cm increase in WC was associated with 3.4 ± 0.6 and 1.05 ± 0.05 g m-2.7 (p < 0.05 for both) higher left ventricular (LV) mass index, respectively. Similarly, 0.1-unit increment in WHR was associated with 2.0 ± 0.16 g m-2.7 higher LV mass index (p < 0.01). WHR was associated with 0.22 ± 0.08% decrease in ejection fraction (p < 0.05). Concomitantly, 5-unit increment in BMI and WC was associated with increased odds of abnormal LV geometry (odds ratio 1.40 and 1.16, p = 0.03 and <0.01, respectively); 0.1-unit increment in WHR was associated with increased odds of abnormal LV geometry (odds ratio 1.51, p < 0.01).

CONCLUSIONS

Among Hispanic/Latinos, higher anthropometric measures were associated with adverse cardiac structure and function.

Genome-wide detection of CNVs associated with beak deformity in chickens using high-density 600K SNP arrays

Beak deformity (crossed beaks) is found in several indigenous chicken breeds including Beijing-You studied here. Birds with deformed beaks have reduced feed intake and poor production performance. Recently, copy number variation (CNV) has been examined in many species and is recognized as a source of genetic variation, especially for disease phenotypes. In this study, to unravel the genetic mechanisms underlying beak deformity, we performed genome-wide CNV detection using Affymetrix chicken high-density 600K data on 48 deformed-beak and 48 normal birds using penncnv. As a result, two and eight CNV regions (CNVRs) covering 0.32 and 2.45 Mb respectively on autosomes were identified in deformed-beak and normal birds respectively. Further RT-qPCR studies validated nine of the 10 CNVRs. The ratios of six CNVRs were significantly different between deformed-beak and normal birds (P < 0.01). Within these six regions, three and 21 known genes were identified in deformed-beak and normal birds respectively. Bioinformatics analysis showed that these genes were enriched in six GO terms and one KEGG pathway. Five candidate genes in the CNVRs were further validated using RT-qPCR. The expression of LRIG2 (leucine rich repeats and immunoglobulin like domains 2) was lower in birds with deformed beaks (P < 0.01). Therefore, the LRIG2 gene could be considered a key factor in view of its known functions and its potential roles in beak deformity. Overall, our results will be helpful for future investigations of the genomic structural variations underlying beak deformity in chickens.

Antibody-mediated thyroid dysfunction during T-cell checkpoint blockade in patients with non-small-cell lung cancer

Background

Programmed cell death protein-1 (PD-1) blockade therapies have demonstrated durable responses and prolonged survival in a variety of malignancies. Treatment is generally well tolerated although immune-related adverse events (irAEs) can occur. Autoimmune thyroid dysfunction is among the most common irAE, but an assessment of the clinical, mechanistic, and immunologic features has not been previously described.

Patient and methods

Patients with advanced non-small-cell lung cancer (NSCLC) treated with pembrolizumab at Memorial Sloan Kettering Cancer Center (n = 51) as part of KEYNOTE-001 (NCT01295827) were included. Thyroid function test and anti-thyroid antibodies were assessed prospectively at each study visit, beginning before the first treatment. Frequency of development of thyroid dysfunction, association with anti-thyroid antibodies, clinical course, and relationship with progression-free survival and overall survival to treatment with pembrolizumab was evaluated.

Results

Of 51 patients treated, 3 were hypothyroid and 48 were not at baseline. Ten of 48 [21%, 95% confidence interval (CI) 10% to 35%] patients developed thyroid dysfunction requiring thyroid replacement. Anti-thyroid antibodies were present in 8 of 10 patients who developed thyroid dysfunction, compared with 3 of 38 who did not (80% versus 8%, P < 0.0001). Thyroid dysfunction occurred early (median, 42 days) in the pembrolizumab course, and a majority (6 of 10 patients) experienced brief, transient hyperthyroidism preceding the onset of hypothyroidism; no persistent hyperthyroidism occurred. Both hyperthyroidism and hypothyroidism were largely asymptomatic. Overall survival with pembrolizumab was significantly longer in subjects who developed thyroid dysfunction (hazard ratio, 0.29; 95% CI 0.09-0.94; P = 0.04).

Conclusions

Thyroid dysfunction during pembrolizumab treatment of NSCLC is common and is characterized by early-onset, frequently preceded by transient hyperthyroidism, closely associated with anti-thyroid antibodies, and may be associated with improved outcomes. The presence of antibody-mediated toxicity in T-cell-directed therapy suggests an under-recognized impact of PD-1 biology in modulating humoral immunity.

A phase II study of axitinib (AG-013736) in patients with incurable adenoid cystic carcinoma

BACKGROUND

Recurrent/metastatic adenoid cystic carcinoma (ACC) is an incurable disease with no standard treatments. The majority of ACCs express the oncogenic transcription factor MYB (also c-myb), often in the context of a MYB gene rearrangement. This phase II trial of the tyrosine kinase inhibitor (TKI) axitinib (Pfizer) tested the hypothesis that targeting pathways activated by MYB can be therapeutically effective for ACC.

PATIENTS AND METHODS

This is a minimax two-stage, phase II trial that enrolled patients with incurable ACC of any primary site. Progressive or symptomatic disease was required. Patients were treated with axitinib 5 mg oral twice daily; dose escalation was allowed. The primary end point was best overall response (BOR). An exploratory analysis correlating biomarkers to drug benefit was conducted, including next-generation sequencing (NGS) in 11 patients.

RESULTS

Thirty-three patients were registered and evaluable for response. Fifteen patients had the axitinib dose increased. Tumor shrinkage was achieved in 22 (66.7%); 3 (9.1%) had confirmed partial responses. Twenty-five (75.8%) patients had stable disease, 10 of whom had disease stability for >6 months. The median progression-free survival (PFS) was 5.7 months (range 0.92-21.8 months). Grade 3 axitinib-related toxicities included hypertension, oral pain and fatigue. A trend toward superior PFS was noted with the MYB/NFIB rearrangement, although this was not statistically significant. NGS revealed three tumors with 4q12 amplification, producing increased copies of axitinib-targeted genes PDGFR/KDR/KIT. Two 4q12 amplified patients achieved stable disease for >6 months, including one with significant tumor reduction and the longest PFS on study (21.8 months).

CONCLUSIONS

Although the primary end point was not met, axitinib exhibited clinical activity with tumor shrinkage achieved in the majority of patients with progressive disease before trial enrollment. Analysis of MYB biomarkers and genomic profiling suggests the hypothesis that 4q12 amplified ACCs are a disease subset that benefit from TKI therapy.

Measurement of the neutron F2 structure function via spectator tagging with CLAS

We report on the first measurement of the F(2) structure function of the neutron from the semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to ≲100 MeV/c and their angles to ≳100° relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F(2)(n) data collected cover the nucleon-resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65<Q(2)<4.52 GeV(2), with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F(2)(n)/F(2)(p) at 0.2≲x≲0.8 with little uncertainty due to nuclear effects.

Skeletal findings in children recently initiating glucocorticoids for the treatment of nephrotic syndrome

SUMMARY

Eighty children with nephrotic syndrome underwent lumbar spine densitometry and vertebral morphometry soon after glucocorticoid initiation. We found an inverse relationship between glucocorticoid exposure and spine areal bone mineral density (BMD) Z-score and a low rate of vertebral deformities (8%).

INTRODUCTION

Vertebral fractures are an under-recognized complication of childhood glucocorticoid-treated illnesses. Our goal was to study the relationships among glucocorticoid exposure, lumbar spine areal BMD (LS BMD), and vertebral shape in glucocorticoid-treated children with new-onset nephrotic syndrome.

METHODS

Lateral thoracolumbar spine radiography and LS BMD were performed in 80 children with nephrotic syndrome (median age 4.4 years; 46 boys) within the first 37 days of glucocorticoid therapy. Genant semiquantitative grading was used as the primary method for vertebral morphometry; the algorithm-based qualitative (ABQ) method was used for secondary vertebral deformity analysis.

RESULTS

Six of the 78 children with usable radiographs (8%; 95% confidence interval 4 to 16%) manifested a single Genant grade 1 deformity each. All deformities were mild anterior wedging (two at each of T6, T7, and T8). Four of the 78 children (5%; 95% confidence interval 2 to 13%) showed one ABQ sign of fracture each (loss of endplate parallelism; two children at T6 and two at T8). Two of the children with ABQ signs also had a Genant grade 1 deformity in the same vertebral body. None of the children with a Genant or ABQ deformity reported back pain. An inverse relationship was identified between LS BMD Z-score and glucocorticoid exposure.

CONCLUSIONS

Although we identified an inverse relationship between steroid exposure and LS BMD soon after glucocorticoid initiation for childhood nephrotic syndrome, there was only a low rate of vertebral deformities. The clinical significance of these findings requires further study.

Absorption of the ω and ϕ mesons in nuclei

Because of their long lifetimes, the ω and ϕ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from 2H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e+e- channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that reported by the CBELSA-TAPS experiment and cannot be explained by recent theoretical models.

Prevalent vertebral fractures among children initiating glucocorticoid therapy for the treatment of rheumatic disorders

OBJECTIVE

Vertebral fractures are an under-recognized problem in children with inflammatory disorders. We studied spine health among 134 children (87 girls) with rheumatic conditions (median age 10 years) within 30 days of initiating glucocorticoid therapy.

METHODS

Children were categorized as follows: juvenile dermatomyositis (n = 30), juvenile idiopathic arthritis (n = 28), systemic lupus erythematosus and related conditions (n = 26), systemic arthritis (n = 22), systemic vasculitis (n = 16), and other conditions (n = 12). Thoracolumbar spine radiograph and dual x-ray absorptiometry for lumbar spine (L-spine) areal bone mineral density (BMD) were performed within 30 days of glucocorticoid initiation. Genant semiquantitative grading was used for vertebral morphometry. Second metacarpal morphometry was carried out on a hand radiograph. Clinical factors including disease and physical activity, calcium and vitamin D intake, cumulative glucocorticoid dose, underlying diagnosis, L-spine BMD Z score, and back pain were analyzed for association with vertebral fracture.

RESULTS

Thirteen vertebral fractures were noted in 9 children (7%). Of these, 6 patients had a single vertebral fracture and 3 had 2-3 fractures. Fractures were clustered in the mid-thoracic region (69%). Three vertebral fractures (23%) were moderate (grade 2); the others were mild (grade 1). For the entire cohort, mean +/- SD L-spine BMD Z score was significantly different from zero (-0.55 +/- 1.2, P < 0.001) despite a mean height Z score that was similar to the healthy average (0.02 +/- 1.0, P = 0.825). Back pain was highly associated with increased odds for fracture (odds ratio 10.6 [95% confidence interval 2.1-53.8], P = 0.004).

CONCLUSION

In pediatric rheumatic conditions, vertebral fractures can be present prior to prolonged glucocorticoid exposure.

Heat recovery ventilators prevent respiratory disorders in Inuit children

Inuit infants have high rates of reported hospitalization for respiratory infection, associated with overcrowding and reduced ventilation. We performed a randomized, double-blind, placebo controlled trial to determine whether home heat recovery ventilators (HRV) would improve ventilation and reduce the risk of respiratory illnesses in young Inuit children. Inuit children under 6 years of age living in several communities in Nunavut, Canada were randomized to receive an active or placebo HRV. We monitored respiratory symptoms, health center encounters, and indoor air quality for 6 months. HRVs were placed in 68 homes, and 51 houses could be analyzed. Subjects had a mean age of 26.8 months. Active HRVs brought indoor carbon dioxide concentrations to within recommended concentrations. Relative humidity was also reduced. Use of HRV, compared with placebo, was associated with a progressive fall in the odds ratio for reported wheeze of 12.3% per week (95%CI 1.9-21.6%, P = 0.022). Rates of reported rhinitis were significantly lower in the HRV group than the placebo group in month 1 (odds ratio 0.20, 95%CI 0.058-0.69, P = 0.011) and in month 4 (odds ratio 0.24, 95%CI 0.054-0.90, P = 0.035). There were no significant reductions in the number of health center encounters, and there were no hospitalizations. Use of HRVs was associated with in improvement in air quality and reductions in reported respiratory symptoms in Inuit children.

PRACTICAL IMPLICATIONS

Reduced ventilation is common in the houses of Inuit children in arctic Canada, and is associated with an increased risk of respiratory infection. Installation of HRV brings indoor carbon dioxide concentration, as a marker of adequate ventilation, to within recommended concentrations, although relative humidity is also reduced. Installation of HRV is associated with improvements in indoor air quality, and a reduced risk of wheezing and rhinitis not associated with cold air exposure in young Inuit children. Further research is required to explore traditional Inuit cultural attitudes about air movement in dwellings.

Prophylaxis of deep-vein thrombosis in fractures below the knee: a prospective randomised controlled trial

The incidence of deep-vein thrombosis and the need for thromboprophylaxis following isolated trauma below the knee is uncertain. We have investigated this with a prospective randomised double-blind controlled trial using low molecular weight heparin with saline injection as placebo in patients aged between 18 and 75 years who had sustained an isolated fracture below the knee which required operative fixation. All patients had surgery within 48 hours of injury and were randomised to receive either the placebo or low molecular weight heparin for 14 days, after which they underwent bilateral lower limb venography, interpreted by three independent radiologists. Further follow-up was undertaken at two, six, eight and 12 weeks. A total of 238 patients fulfilled all the inclusion criteria, with 127 in the low molecular weight heparin group and 111 in the placebo group, all of whom underwent bilateral venography. There was no statistically significant difference in the incidence of deep-vein thrombosis between those patients treated with low molecular weight heparin or the placebo (p = 0.22). The number of deep-vein thromboses in the two groups was 11 (8.7%) and 14 (12.6%), respectively. Age and the type of fracture were significantly associated with the rate of deep-vein thrombosis (p = 0.001 and p = 0.009, respectively) but gender, comorbidities and the body mass index were not. The overall incidence of deep-vein thrombosis in this series was 11%. There was no clinical or statistical significant reduction in the incidence of deep-vein thrombosis with the use of thromboprophylaxis. However, we accept that owing to a cessation of funding, recruitment to this trial had to be ended prior to establishing the necessary sample size. Our results cannot, therefore, categorically exclude the possibility that low molecular weight heparin treatment could be beneficial. We recommend a further multicentre trial be undertaken to resolve this matter.

Molecular cloning and expression of rat bradykinin B1 receptor

The gene encoding rat bradykinin B1 receptor has been cloned by using a partial rat B1 cDNA probe. The rat B1 receptor gene contains two exons and the entire coding region is within the second exon. The 5'-flanking region of the rat B1 receptor gene contains several putative transcriptional regulatory sites including TATA box, cAMP response element, NF-kappaB and AP-1. It showed promoter activity inducible by lipopolysaccharide in vascular smooth muscle cells. Rat B1 receptor mRNA was found to be alternatively spliced and induced by lipopolysaccharide treatment in a wide range of tissues, such as the salivary gland, testis, kidney, lung, heart, prostate and aorta. The deduced rat B1 receptor amino acid sequence is 71% homologous to human and rabbit counterparts, and 89% homologous to the mouse counterpart. The expressed B1 receptor in HEK293 cells displayed a rank order of affinity for the kinin peptides: des-Arg9-BK>Lys-des-Arg9-BK approximately des-Arg9, Leu8-BK>Sar-Tyr-epsilonAhx-Lys-[D-betaNal7, Ile8]-des-Arg9-BK>Sar-Tyr-epsilonAhx-Lys-des-Arg9-BK>>BK>> Hoe140. These results indicate that the cloned gene encodes a functional rat B1 receptor.

Transcription factor nuclear factor kappaB regulates the inducible expression of the human B1 receptor gene in inflammation

Expression of the bradykinin B1 receptor gene is up-regulated in vascular smooth muscle cells (VSMCs) in response to a variety of inflammatory stimuli. We isolated the 5'-flanking region of the human bradykinin B1 receptor gene and examined its promoter activity by transient transfection analysis. This region (-2582 to +34) showed promoter activity inducible by lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), and interleukin-1beta (IL-1beta) in VSMCs. Further deletion analysis revealed that constructs containing 111 base pairs of 5'-flanking sequence were sufficient for transcriptional induction. Mutagenesis of a nuclear factor kappaB (NF-kappaB)-like site at -64 to -55 abolished most of the LPS, TNF-alpha, and IL-1beta inducibility, whereas a mutation of a cyclic AMP response element at -50 to -43 markedly reduced the basal promoter activity, and a mutation of the activator protein 1 (AP-1) site at -78 to -72 had minimal effects. Nuclear extracts from LPS, TNF-alpha, and IL-1beta-treated VSMCs, IL-1beta-treated human hepatoma HepG2, and human lung fibroblast IMR-90 cells showed strong inducible binding activity to the NF-kappaB-like site by gel shift assays. These results demonstrated that NF-kappaB-like nuclear factor was involved in the inducible expression of the human bradykinin B1 receptor gene during inflammatory processes.

Molecular cloning and expression of rat kallistatin gene

We have previously purified and cloned human kallistatin and rat kallikrein-binding protein (RKBP), which are tissue kallikrein inhibitors belonging to the serine proteinase inhibitor superfamily. In this study, we have cloned and sequenced the gene encoding rat kallistatin with Phe-Phe-Ser-Ala-Gln at positions P2-P3', which is identical to the reactive center of human kallistatin. Rat kallistatin is highly similar to human kallistatin, sharing 68% and 57% sequence identity at the cDNA and the amino acid levels. The rat kallistatin gene exists in a single copy and is located on chromosome 6. An SphI RFLP is found between SHR and WKY rats at or near the rat kallistatin gene locus. Two amino acid polymorphisms of the rat kallistatin gene between these two strains were found by sequence analysis. A candidate promoter in the 5'-flanking region (109 bp) of the rat kallistatin gene has been identified by reporter assays. The expression of rat kallistatin in the liver is growth-dependent and down-regulated during acute phase inflammation. Recombinant rat kallistatin produced in E. coli is able to bind to tissue kallikrein, and the interaction is inhibited by heparin. These characteristics define rat kallistatin as the counterpart of human kallistatin.

Genomic DNA sequence, expression, and chromosomal localization of the human B1 bradykinin receptor gene BDKRB1

We have cloned and sequenced the human B1 bradykinin receptor gene (BDKRB1), which contains an uninterrupted coding exon. A putative promoter was identified by linking various lengths of the 5'-flanking region of the B1 receptor gene coding sequence to a CAT reporter and assaying for CAT activity. Deletion analysis showed that a 300-bp fragment in the promoter region is sufficient to direct the synthesis of the reporter and that an enhancer-like element is present between -1842 and -812. A genomic Southern blot using the B1 cDNA revealed that the receptor is encoded by a single-copy gene. The gene is located on chromosome 14q32.1-q32.2, in close proximity to the B2 receptor gene. Northern blot analysis identified a 1.7- to 1.8-kb mature mRNA transcript of the B1 receptor gene in the kidney and pancreas. A widespread tissue distribution of the B1 gene expression was identified by RT-PCR-Southern blot analysis using specific oligonucleotide probes.

[Species-specific monoclonal antibodies against the major outer membrane protein (MOMP) of Chlamydia trachomatis]

The synthesized one quarter N-terminal MOMP of C. trachomatis was used for primary immunization of three male BALB/c mice (8 weeks of age), and the boost with C. trachomatis L1/440/Bu elementary bodies (EBs) was followed on day 14. Spleen cells from one mouse with good response of immunization were fused with murine myeloma NS-1 cells on day 24. The hybrid cell suspension was seeded into the wells of 96-well microtest plates which contained macrophage feeder layers. Anti-chlamydial antibodies in culture fluids were screened by ELISA with 1/4 MOMP & L1 EBs coated 96-well trays. Positive wells were cloned by limiting dilution. Four clones which secreted immunoglobulin G1 & G2a class were obtained after elimination of those clones that produced antibodies to C. psittaci strain EAE, C. pneumoniae strain ATCC VR1310 and uninfected BGMK cells. In micro-IF test, we found that the all four clones of MAbs reacted with our laboratory prepared L1, L2, A, B, C, E EBs, L2 tissue culture inclusions, as well as the EBs of all 15 standard serovars of C. trachomatis. The titers of their ascites were more than 1:12,800 in micro-IF test. It was shown that the four clones of MAbs reacted predominantly with 40,000 MOMP of C. trachomatis L1 in Western blot.

[Chlamydia pneumoniae infection in patients with pneumonia, bronchitis and acute upper respiratory tract infection in Beijing]

A prospective study for C. pneumoniae infection was conducted in 134 patients with acute respiratory disease and 134 matched patients with other medical reasons from January to May 1994 in Beijing. The positive rate of micro-IF (MIF) IgG antibodies was 93% (125/134) and 89% (119/134) respectively (0.1 < P < 0.25) and the geometric mean titers (GMT) were not found to be significant (55.9 +/- 4.2 vs 41.7 +/- 2.8, 0.1 < P < 0.20). Ten patients, four (4/30) with pneumonia and six (6/81) with bronchitis were serologically diagnosed as having recent C. pneumoniae infection. Chronic bronchitis was statistically more frequent in patients with C. pneumoniae infection than those without (0.025 < P < 0.05). Patients with chronic bronchitis (GMT, 87.1 +/- 3.9; n = 36) tended to have higher IgG titers than those without (GMT, 47.6 +/- 4.1; n = 98, 0.02 < P < 0.05). Culture of retro-pharyngeal swab specimens for C. pneumoniae was negative in the all 134 studied patients.

Interaction of calmodulin with synthetic deletion peptides of melittin

The 26-residue peptide melittin present in bee venom has been shown to bind calmodulin tightly. In this study we synthesized the following series of deletion peptides of melittin by the solid-phase method: Mel12, Mel13, Mel14, Mel15, Mel15F. The results of this study show that the deletion peptides Mel14 and Mel15 have almost the same binding activity as the intact native peptide. Each deletion peptide forms a 1:1 complex with calmodulin according to electrophoresis analysis. When the tryptophanyl residue of Mel15 was replaced by the phenylalaninyl residue, the dissociation constant of the peptide-calmodulin complex increased. This shows the importance of the tryptophanyl residue for binding to calmodulin.