Somatostatin receptor PET/MR imaging of large vessel inflammation in active compared with inactive vasculitis and atherosclerosis

Background

Use of 18F-FDG PET in large vessel vasculitis (LVV) is limited by non-specific uptake due to arterial remodelling and/or atherosclerosis leading to diagnostic uncertainty.

Purpose

To investigate somatostatin receptor 2 (SST2) as a novel inflammation-specific PET imaging target in LVV.

Methods

In a prospective observational cohort study, we tested the ability of PET/MRI using two somatostatin receptor tracers (68Ga-DOTATATE and 18F-FET-βAG-TOCA) to differentiate active from inactive LVV, and aortic atherosclerosis in patients with recent myocardial infarction. Ex vivo mapping of the imaging target was performed using immunofluorescence microscopy, imaging mass cytometry, and bulk, single-cell and single-nuclei RNA sequencing of temporal artery biopsies from LVV patients.

Results

Sixty-one participants were included (LVV, n=27; myocardial infarction ≤2 weeks, n=25; control subjects with an oncological indication for imaging, n=9). LVV patients (mean age 58 [SD 16] years; 78% female; 63% active or grumbling disease) had giant cell arteritis (n=13), Takayasu arteritis (n=13), or unspecified LVV (n=1). Baseline index vessel SST2 PET maximum tissue-to-blood ratio (TBRmax) was 61.8% (95% CI 31.5–99.0%, p<0.0001) higher in patients with active/grumbling LVV than inactive LVV, and 34.6% (95% CI 15.1–57.6%, p=0.0002) higher than recent myocardial infarction (Fig. 1a–c; arrow: PET signal; arrowhead: aortic thickening; asterisk: aortic atherosclerosis), with good diagnostic accuracy (AUC ≥0.86, p<0.001 for both). None of the control subjects without LVV or MI had increased arterial SST2 PET signal (Fig. 1d).

Mean aortic TBRmax was strongly correlated with Indian Takayasu Clinical Activity Score (r=0.82 [95% CI 0.46–0.95], p=0.001) and maximum wall thickness on MRI (r=0.68 [95% CI 0.31–0.87], p=0.002). SST2 PET/MRI was generally consistent with 18F-FDG PET/CT in LVV patients with contemporaneous scans (Fig. 1a, b), but with very low background signal in the brain and heart allowing for unimpeded assessment of nearby coronary, myocardial, and intracranial artery involvement. On follow-up imaging after a mean 9.3 (SD 3.2) months, clinically effective treatment for LVV was associated with a 0.49 ±SEM 0.24 (p=0.04; 22.3%) reduction in SST2 PET TBRmax, with good scan-scan repeatability in inactive LVV patients with no change in treatment (ICC 0.86, 95% CI 0.04–0.99).

SST2 localised to macrophages, pericytes, and perivascular adipocytes in inflamed arterial specimens (Fig. 2; a: H&E; b: imaging mass cytometry; arrow: SST2/CD68 co-staining). SSTR2-expressing macrophages co-expressed pro-inflammatory markers (S100A8, S100A9). Specific SST2 radioligand binding was confirmed by autoradiography in LVV specimens.

Conclusion

This is the first study to examine SST2 PET/MRI in LVV and to provide histological and gene expression data for validation. Here we show this novel approach holds major promise for diagnosis and therapeutic monitoring in LVV.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Wellcome Trust; Imperial NIHR Biomedical Research Centre

Prevalence of disordered eating in adults with gastrointestinal disorders: A systematic review

BACKGROUND

Patients with gastrointestinal disorders are prone to heightened awareness of dietary intake. When diet-related thoughts or behaviors are excessive, they may lead to psychological distress, nutritional compromise, and impair medical treatment. Identification of disordered eating behavior and eating disorders is crucial for effective management, but data on their prevalence within this population remain scarce. We conducted a systematic review of the prevalence of disordered eating behavior and eating disorders in adults with gastrointestinal disorders.

METHODS

MEDLINE, PubMed, and PsycInfo databases were searched up to June 2021. Studies examining disordered eating in adult patients with a primary gastrointestinal diagnosis were included.

KEY RESULTS

A total of 17 studies met the inclusion criteria for the review. The range of gastrointestinal disorders examined included disorders of gut-brain interaction (DGBI), coeliac disease, and inflammatory bowel disease (IBD). The methods for examining disordered eating were highly variable. The prevalence of disordered eating ranged from 13-55%. The prevalence was higher in patients with disorders of gut-brain interaction (DGBI) than in those with organic gastrointestinal disorders. Factors associated with disordered eating included female sex, younger age, gastrointestinal symptom severity, anxiety and depression, and lower quality of life.

CONCLUSIONS & INFERENCES

Disordered eating is highly prevalent in adult patients with gastrointestinal illness, particularly those with DGBI. Understanding whether a patient's primary underlying diagnosis is that of an eating disorder or gastroenterological disorder remains a challenge for clinicians. There is an unmet need to identify at-risk patients so that psychological intervention can be included in the therapeutic strategy.

Reporter bacteriophage T7NLC utilizes a novel NanoLuc::CBM fusion for the ultrasensitive detection of Escherichia coli in water

Rapid detection of bacteria responsible for foodborne diseases is a growing necessity for public health. Reporter bacteriophages (phages) are robust biorecognition elements uniquely suited for the rapid and sensitive detection of bacterial species. The advantages of phages include their host specificity, ability to distinguish viable and non-viable cells, low cost, and ease of genetic engineering. Upon infection with reporter phages, target bacteria express reporter enzymes encoded within the phage genome. In this study, the T7 coliphage was genetically engineered to express the newly developed luceriferase, NanoLuc (NLuc), as an indicator of bacterial contamination. While several genetic approaches were employed to optimize reporter enzyme expression, the novel achievement of this work was the successful fusion of the NanoLuc reporter to a carbohydrate binding module (CBM) with specificity to crystalline cellulose. This novel chimeric reporter (nluc::cbm) bestows the specific and irreversible immobilization of NanoLuc onto a low-cost, widely available crystalline cellulosic substrate. We have shown the possibility of detecting the immobilized fusion protein in a filter plate which resulted from a single CFU of E. coli. We then demonstrated that microcrystalline cellulose can be used to concentrate the fusion reporter from 100 mL water samples allowing a limit of detection of <10 CFU mL-1E. coli in 3 hours. Therefore, we conclude that our phage-based detection assay displays significant aptitude as a proof-of-concept drinking water diagnostic assay for the low-cost, rapid and sensitive detection of E. coli. Additional improvements in the capture efficiency of the phage-based fusion reporter should allow a limit of detection of <10 CFU per 100 mL.

Insulin pump therapy in children and adolescents: changes in dietary habits, composition and quality of life

AIM

Continuous subcutaneous insulin infusion (CSII) can improve glycaemic control and dietary flexibility compared with conventional insulin therapies. There is little information on whether users are utilising this increased dietary flexibility, and whether dietary quality is affected.

METHODS

A pre-post observational study was undertaken in 28 children and adolescents with type 1 diabetes commencing CSII. Meal pattern and dietary composition was examined from 3-day food diaries completed before and 3-6 months after CSII commencement. Participants completed the Diabetes-Specific Quality of Life for Youth Short Form, and body mass index z-score, and glycated haemoglobin were measured. A second posttest was undertaken at 18 months with those who were still on CSII and contactable (n = 18).

RESULTS

Energy and macronutrient intake before and 18 months after CSII commencement were unchanged. Mean snacking events decreased significantly by 1.2 snacks per day (P = 0.009), as did the percentage energy derived from snacks (28.8%, 95% confidence interval (CI) 21.5-36.1 vs. 19.3%, 95% CI 13.2-25.4; P = 0.045). Diabetes-Specific Quality of Life for Youth Short Form score was not significantly affected by pump commencement (25.9 95% CI 18.2-33.6), and body mass index z-score remained similar before and after CSII. Glycated haemoglobin decreased by 0.5% in the 3-6 months following CSII commencement, but was similar to baseline at 18 months.

CONCLUSIONS

This study demonstrates that the commencement of CSII did not lead to an abandonment of healthy eating principles, and that patients utilised the increased dietary flexibility to make changes to their snacking pattern.

Tn7: smarter than we thought

A notable feature of transposable elements--segments of DNA that can move from one position to another in genomes--is that they are highly prevalent, despite the fact that their translocation can result in mutation. The bacterial transposon Tn7 uses an elaborate system of target-site selection pathways that favours the dispersal of Tn7 in diverse hosts as well as minimizing its negative effects.

Tn7 recognizes transposition target structures associated with DNA replication using the DNA-binding protein TnsE

We report that the bacterial transposon Tn7 selects targets by recognizing features associated with DNA replication using the transposon-encoded DNA-binding protein TnsE. We show that Tn7 transposition directed by TnsE occurs in one orientation with respect to chromosomal DNA replication, indicating that a structure or complex involved in DNA replication is likely to be a critical determinant of TnsE insertion. We find that mutant TnsE proteins that allow higher levels of transposition also bind DNA better than the wild-type protein. The increased binding affinity displayed by the TnsE high-activity mutants indicates that DNA binding is relevant to transposition activity and suggests that TnsE interacts directly with target DNAs. In vitro, TnsE interacts preferentially with certain DNA structures, indicating a mechanism for the TnsE-mediated orientation and insertion preference. The pattern of TnsE-mediated insertion events around the Escherichia coli chromosome provides insight into how DNA replication forks proceed in vivo.

Tn7 transposes proximal to DNA double-strand breaks and into regions where chromosomal DNA replication terminates

We report that the bacterial transposon Tn7 can preferentially transpose into regions where chromosomal DNA replication terminates. DNA double-strand breaks are associated with the termination of chromosomal replication; therefore, we directly tested the effect of DNA breaks on Tn7 transposition. When DNA double-strand breaks are induced at specific sites in the chromosome, Tn7 transposition is stimulated and insertions are directed proximal to the induced break. The targeting preference for the terminus of replication and DNA double-strand breaks is dependent on the Tn7-encoded protein TnsE. The results presented in this study could also explain the previous observation that Tn7 is attracted to events associated with conjugal DNA replication during plasmid DNA transfer.

Streptococcus pyogenes transmission among Air Force recruits: efficacy of surveillance and prophylaxis protocols

The prevalence of Streptococcus pyogenes in Air Force recruits (n = 10,634) completing basic training at Lackland Air Force Base between November 1, 1993, and March 1, 1994, was determined. Throat cultures were obtained on the second day and the last day of training, approximately 6 weeks later. Although the prevalence on the second day was nearly identical between males (1.99%) and females (1.98%), males with positive cultures increased to 4.30%, whereas females with positive cultures increased to 2.92% at the end of training. Within flights, an increase was noted in male flights when members sought care and subsequently were positive for S. pyogenes. Within these flights, S. pyogenes prevalence significantly increased from 2.79 to 7.20% (p < 0.001) despite antibiotic therapy and prophylaxis treatment measures. Within female flights, the increase was from 2.68 to 3.35%, which was not statistically significant (p < 0.19). A total of 161 trainees were treated for S. pyogenes as a result of positive cultures; remarkably, 27.3% of these were still culture-positive on the last day of training.

Annular phase-matched dual-pump coherent anti-stokes Raman spectroscopy system for the simultaneous detection of nitrogen and methane

The concentration and pressure dependence of dual-pump coherent anti-Stokes Raman spectroscopy (CARS) signals from nitrogen and methane was investigated. CARS spectra were acquired from a gas cell at pressures of 0.007 to 2.24 MPa and methane concentrations of 0.5 to 50%. The square root of the methane signal intensity divided by the nitrogen signal intensity was found to have a near-linear dependence on methane concentration at all pressures investigated. The pressure dependence of this integrated intensity ratio decreased with increasing pressure and became negligible at the highest pressures tested. The shot-to-shot variation at concentrations determined from single-laser-shot measurements was less than 7%. Single-laser-shot CARS spectra of nitrogen and methane were obtained from the cylinder of a firing direct-injection natural gas engine.

Pressure dependence of laser-induced fluorescence from acetone

The use of laser-induced fluorescence (LIF) from acetone is becoming increasingly widespread as a diagnostic of mixing processes in both reacting and nonreacting flows. One of the major reasons for its increasing use is that the acetone LIF signal is believed to be nearly independent of pressure because of fast intersystem crossing from the first excited singlet state, from which the fluorescence signal originates, to the first excited triplet state, which does not fluoresce. To evaluate the use of acetone LIF at pressures higher than atmospheric, we have performed a study of acetone LIF in a flowing gas cell at pressures up to 8 atm. We used four different buffer gases: air, nitrogen, methane, and helium. Surprisingly, we find that the acetone fluorescence quantum efficiency increases slightly (~30%-50%) as the buffer-gas pressure increases from 0.6 to 5 atm for all four buffer gases. When the buffer gas is air, we observe a decrease in the acetone fluorescence quantum efficiency as the buffer-gas pressure is increased from 5 to 8 atm; for the other three buffer gases the quantum efficiency is constant to within experimental error in this pressure regime. The observed pressure dependence of the acetone fluorescence signal is explained by use of a four-level model. The increase in the fluorescence quantum efficiency with pressure is probably the result of incomplete vibrational relaxation coupled with an increase in the intersystem crossing rate with increasing vibrational excitation in the first excited singlet manifold.

Nerve blocks for regional anesthesia of the face

Many trauma repairs and dermatologic procedures performed on the face require anesthesia of the involved area. The specific requirements for anesthesia and vasoconstriction vary, depending on the location, size and depth of the injury or lesion. Direct infiltration of anesthetic is very uncomfortable, and adequate anesthesia may require multiple injections. In addition, direct infiltration of a volume of anesthetic sufficient to produce adequate anesthesia can cause distortion of the tissue, hindering the identification of margins. Intraoral nerve blocks routinely used by dentists can achieve safe and effective regional anesthesia in the anterior portion of the face.

Simplified quantitation of urinary benzoylecgonine in cocaine addiction research and for related pharmacotherapeutic trials

In clinical trials of potential pharmacotherapies for cocaine addiction, objective determination of subject relapse relies on qualitative urine analysis for benzoylecgonine, the major metabolite of cocaine. Unlike qualitative analysis, quantitative measurement allows differentiation between continued cocaine use and a single use, as well as identification of changes in the quantity of cocaine used at different times. The only quantitative technique that has been used is expensive and not generally feasible. This study was performed to modify an existing qualitative technique for use as a new simple and readily available quantitative method for identifying cocaine use among research subjects. Benzoylecgonine levels in 24-hour urine specimens collected from 11 cocaine-addicted subjects hospitalized in a research setting were measured semi-quantitatively by fluorescence polarization immunoassay. Accurate results required thorough mixing of urine specimens prior to analysis. At admission, eight subjects had urinary benzoylecgonine levels > or = 0.30 microgram/ml, the standard positive/negative cut-off used in qualitative analysis. The mean half-life of benzoylecgonine during initial elimination was 0.46 +/- 0.08 (SEM, n = 8) days. Benzoylecgonine (BE)/creatinine (C) levels remained > or = 0.30 microgramBE/mgC for 4.8 +/- 0.5 (n = 8) days and > or = 0.03 microgramBE/mgC for 10.5 +/- 1.5 (n = 8) days. Relapses in three subjects could be identified by quantitative analysis. This study indicates that quantitation of benzoylecgonine in daily urine specimens provides a sensitive, objective index to cocaine use.

Measuring the effect of the Rorschach color cards (VIII-X) on perceptual accuracy and special scores in differentiating borderline from schizophrenic protocols

In this study, measures were developed that compared conventional Form accuracy and the ratio of Special Scores on Cards VIII-X (Color Cards) with overall Rorschach scores. Two new measures, a Color Card Perception Difference (CCPD) score and a Special Score Difference (SSD) score were used for this purpose. CCPD and SSD scores were calculated by subtracting component X + % scores and weighted Special Score ratios found on the overall Rorschach from those unique to Cards VIII-X. CCPD scores were found to be highly effective in differentiating a previously diagnosed borderline from a schizophrenic group. CCPD and SSD scores were correlated with MMPI scales for profile characteristics.

Redundant homosexual F transfer facilitates selection-induced reversion of plasmid mutations

F plasmids use surface exclusion to prevent the redundant entry of additional F plasmids during active growth of the host cells. This mechanism is relaxed during stationary phase and nonlethal selections, allowing homosexual redundant plasmid transfer. Homosexual redundant transfer occurs in stationary-phase liquid cultures, within nongrowing populations on solid media, and on media lacking a carbon source. We examined the relationship between homosexual redundant transfer, which occurs between F+ hosts, and reversion of a plasmid-encoded lac mutant allele, lacI33omegalacZ. Sodium dodecyl sulfate (SDS) and mutations that prevent normal transfer to F- cells reduced redundant transfer and selection-induced reversion of the lacI33omegalacZ allele. A recA null mutation reduced redundant transfer and selection-induced reversion of the lacI33omegalacZ mutation. Conversely, a recD null mutation increased redundant transfer and selection-induced reversion of the lacI33omegalacZ allele. These results suggest an explanation for why SDS and these mutations affect reversion of the plasmid lacI33omegalacZ allele. However, a direct causal relationship between transfer and reversion remains to be established. These results suggest that Rec proteins play an active role in redundant transfer and/or that redundant transfer is regulated with the activation of recombination. Redundant homosexual plasmid transfer during a period of stress may represent a genetic response that facilitates evolution of plasmid-encoded functions through mutation, recombination, reassortment, and dissemination of genetic elements present in the populations.

Availability of reliable serum methadone determination for management of symptomatic patients

Methadone, when used in the appropriate dose, prevents opioid withdrawal during the 24-hour period following medication. However, the appropriate dose for a given patient may be difficult to determine due to variations in methadone metabolism which is affected by many factors. Early opioid withdrawal, requiring a higher dose of methadone, is often difficult to diagnose because many of the symptoms are also symptoms of other syndromes common in the methadone maintenance population. In this study, ten patients in stable methadone maintenance treatment reporting > or = 4 Himmelsbach signs of abstinence were compared with ten patients reporting fewer symptoms. Until recently, accurate, precise, and affordable determination of serum methadone level has not been readily available from commercial laboratories. This study has found that such measures are now available. Serum specimens from each subject were sent to three commercial laboratories for determination of serum methadone level. Results from the three laboratories were highly correlated. No statistical correlation was found between serum methadone level and number of Himmelsbach signs. Of the subjects reporting four or more symptoms, 40% had low serum methadone levels ( < 150 ng/ml); 60% did not. Of the subjects reporting fewer than four symptoms, 90% had serum methadone levels > or = 150 ng/ml. Subjects with > or = 4 Himmelsbach signs had lower dose-adjusted serum methadone levels, the amount of methadone circulating per mg dose, (t = 1.54, p < .0702). Thus, for patients who report symptoms which could be attributable to opioid withdrawal, measurement of serum methadone level may help to differentiate complaints due to early abstinence from those due to other medical conditions.

Characterization of a new rho mutation that relieves polarity of Mu insertions

We report the identification and characterization of a new rho mutation, rho614, that relieves polarity of Mu insertions in Escherichia coli. The mutation was identified by its ability to suppress the polarity of the Mu-mediated phi(lamB'-'lacZ)hyb61-4 fusion that is located at codon four of the lamB signal sequence. The rho614 mutation alters residue 80 in the proposed RNA-binding domain of Rho and is recessive to wild-type rho. We suggest that in the presence of the rho614 allele transcripts initiated at the Mu promoter PcM fail to terminate at presumptive Rho-dependent termination sites, namely rut1 and rut2, and continue into the 3' 'lamB gene allowing a LamB+ phenotype. This contention is supported by deletion analysis of the region and the observation that insertional inactivation of genes that reduce transcription from PcM, clpP (ATP protease), himA (IHF-alpha), and himD (IHF-beta), block the LamB+ phenotype. rho614, rho4 and rho201 alleles suppress the polarity of a malK::Mu insertion on the downstream lamB gene. However, the polarity of the phi(lamB'-'lacZ)hyb61-4 insertion is only suppressed by the rho614 mutation. We propose that the rho614 mutation allows suppression of transcriptional polarity without interfering with translation initiation signals of the truncated 'lamB gene. In addition to identifying a new rho mutation and Rho-dependent terminator sequence, this system provides a means of studying Rho protein/terminator relationships through the identification of new classes of rho mutations.

Redundant transfer of F' plasmids occurs between Escherichia coli cells during nonlethal selections

Surface exclusion is the mechanism by which F plasmids prevent the redundant entry of additional F plasmids into the host cell during exponential growth. This mechanism is relaxed in cells that are in stationary phase. Using genetically marked F' plasmids and host strains, we extend this finding to Escherichia coli populations during extended nonlethal selection in bacterial lawns. We show that a high level of redundant transfer occurs between these nongrowing cells during the selection. This result has implications for the mechanism of adaptive mutagenesis.

Developmental patterns of laryngeal and respiratory function for speech production

Estimates of subglottal air pressure, laryngeal airflow, and laryngeal airway resistance from syllable repetitions of children and adults were used in describing developmental changes in these variables and in hypothesizing corresponding changes in respiratory function. A trend was found for pressure and resistance to decrease with increases in flow from preschool age through adulthood. These patterns could be explained by the smaller size of laryngeal airway structures and increased expiratory muscle forces during speech in the younger subjects. When the subglottal air pressures were combined with published data on air volume expired during speech and recoil pressures of the respiratory system, hypothetical functions were derived for respiratory muscle forces and the work of speech breathing. These functions predict (a) a developmental shift from the use of net expiratory muscle force in the speech of preschool children to the adult patterns of combined inspiratory and expiratory muscle forces, and (b) the expiratory work of speech breathing is greater in preschool children than in older children and adults.

Real-time molecular epidemiologic analysis of an outbreak of Streptococcus pyogenes invasive disease in US Air Force trainees

OBJECTIVE

To determine if molecular epidemiologic techniques, including comparative automated DNA sequencing of polymorphic virulence genes, could be used in the course of a bacterial disease outbreak to unambiguously determine clonal relationships among implicated strains.

DESIGN

Strains recovered from all patients with invasive infections and a sample of carriers were analyzed by multilocus enzyme electrophoresis and automated DNA sequencing of a gene encoding an extracellular protease and a highly polymorphic part of the streptokinase gene.

SETTING

A US Air Force training facility in San Antonio, Tex.

PATIENTS

A squadron with about 800 Air Force trainees, including three recruits with invasive Streptococcus pyogenes infections.

RESULTS

Multilocus enzyme electrophoresis and automated DNA sequencing of polymorphic virulence genes unambiguously defined person-to-person spread of an otherwise rare S pyogenes clone in the course of the disease outbreak and clarified strain relationships in real time.

CONCLUSIONS

Molecular strain characterization techniques can be employed rapidly in a disease outbreak to definitively resolve complex relationships among pathogenic bacteria, infer patterns of clone spread, and help formulate rational public health control measures. The approach has broad applicability to other infectious agents.

Further studies on Pseudomonas aeruginosa LasA: analysis of specificity

Full elastolytic activity in Pseudomonas aeruginosa is a result of the combined activities of elastase, alkaline proteinase, and the lasA gene product, LasA. The results of this study demonstrate that an active fragment of the LasA protein which is isolated from the culture supernatant fraction is capable of degrading elastin in the absence of elastase, thus showing that LasA is a second elastase produced by this organism. In addition, it is shown that LasA-mediated enhancement of elastolysis results from the separate activities of LasA and elastase upon elastin. The LasA protein does not affect the secretion or activation of a proelastase as previously proposed in other studies. Furthermore, LasA has specific proteolytic capability, as demonstrated by its ability to cleave beta-casein. Preliminary analysis of beta-casein cleavage in the presence of various protease inhibitors suggests that LasA may be classified as a modified serine protease.

Correlates of vestibular evaluation results during the first year of life

Prenatal and perinatal correlates of abnormal auditory brainstem responses in neonates have been studied extensively. In contrast, vestibular function during the first year of life has received sparse attention. Using a specially modified vestibular test battery, 65 infants (17 low-risk, 48 high-risk) were initially evaluated during their first 6 months of life. Results revealed normal vestibular function in 46 infants (13 low-risk, 33 high-risk) and abnormal findings at either 3 or 6 months in 19 infants (4 low-risk, 15 high-risk). Correlations between vestibular results and variables such as auditory brainstem response results, birth history, and postnatal course in the neonatal intensive care unit were analyzed statistically. While some differences were mildly significant, none were highly significant. The lack of significant correlation between abnormal auditory brainstem response and vestibular results is of particular interest.

Purification and characterization of an active fragment of the LasA protein from Pseudomonas aeruginosa: enhancement of elastase activity

A 22-kilodalton protein purified from the culture supernatant fraction of Pseudomonas aeruginosa (strains PA220 and PAO1) was found to enhance the elastolytic activity of purified P. aeruginosa elastase. N-terminal sequence analysis identified the protein as a fragment of the lasA gene product (P.A. Schad and B.H. Iglewski, J. Bacteriol. 170:2784-2789, 1988). However, comparative analysis with the reported LasA sequence indicated that the purified LasA fragment is longer than the deduced sequence reported. The purified LasA fragment had minimal elastolytic and proteolytic activity and did not enhance the proteolytic activity of purified elastase, yet enhanced the elastolytic activity more than 25-fold. The LasA fragment was found to also enhance the elastolytic activities of thermolysin, human neutrophil elastase, and proteinase K. The results presented here suggest that the LasA protein interacts with the elastin substrate rather than modifying elastase.

Optical constants of liquid isooctane at 3.39 microm

An experimental measurement of the complex refractive index of liquid isooctane at 3.39 microm was made using a two angle reflectance technique. A fused quartz prism was used to suppress liquid evaporation and to prevent index gradients above the liquid surface so that a liquid temperature range from 23 to 80 degrees C could be studied. Results indicate that the real part of the refractive index remains relatively constant over the temperature range decreasing from 1.440 to 1.406. The extinction coefficient, however, increased from 0.0654 to 0.0808 over this temperature range due to the redistribution of molecular states. The errors on the real and imaginary parts of the refractive index are estimated to be 0.05% and 3.0%, respectively.

Development of polyclonal and monoclonal antibodies to iodinated contrast media

Two independent systems were developed to produce antibodies to diatrizoate. In the rabbit model polyclonal antibodies were produced that showed cross-reactivity to certain other contrast agents, analogues and serum proteins. In the mouse model monoclonal antibodies were produced that reacted only with diatrizoate, metrizamide, and ovalbumin. These studies demonstrated the potential antigenicity of contrast medium.

Expandable intraluminal vascular graft: a feasibility study

An expandable intraluminal graft mounted coaxially over an angioplasty balloon catheter was used in dog arteries. The graft, a wire mesh tube that has the ability to retain its expanded shape, opposes elastic recoil of the arterial wall after maximum balloon inflation. Eighteen grafts were placed in the abdominal aorta and iliac femoral, renal, superior mesenteric, and carotid arteries of eight dogs through femoral or carotid arteriotomies. Two grafts were placed in areas of artificially induced stenosis, completely restoring the lumen. Overall patency rate at 35 weeks was 77%. Histopathologic examination of patent grafts showed complete endothelialization at 3 weeks. The smaller caliber grafts and those that had outflow obstruction showed significant degrees of intimal hyperplasia.

Intellectual, behavioral, and linguistic characteristics of three children with 18p- syndrome

Developmental characteristics of three girls with 18p- syndrome are described, with detailed history and results of psychological and speech/language evaluations completed at various ages. Results suggest that some children with 18p- syndrome have average abilities in selected areas, despite previous reports that these children have mild to severe mental retardation. Two of the three girls had more severe deficits in linguistic, as opposed to nonlinguistic, abilities. All had similar difficulties with speech articulation. It is suggested that children with speech/language delays who have physical features associated with this syndrome have chromosome analysis performed. It is also recommended that children identified as having 18p- syndrome be referred for comprehensive developmental assessments and remedial special education programming before a specific prognosis is determined.

The normal mucosal surface pattern of the duodenal bulb: radiologic-histologic correlation

Similar to the stomach and colon, the duodenum also demonstrates a fine mucosal relief pattern on double-contrast radiographic examination. Two patterns may be identified--fine reticular and "small dot." In order to investigate the origin of these patterns, duodenal bulb specimens were obtained at autopsy, and macroscopic and microscopic features were correlated with radiographic patterns. Findings indicate that the surface patterns identified radiographically on cadaveric specimens and in live patient subjects are due to villi and the collections of barium within the intervening sulci. Knowledge of this normal pattern will prevent misdiagnoses, especially when inflammatory disease of the duodenum is being considered.

Pulmonary uptake of mannitol as an index of changes in lung epithelial permeability

To develop a simple, inexpensive, and nontoxic test for changes in bronchial permeability we have employed a specific gas chromatographic assay to measure the uptake of mannitol from the lung after administration of an intratracheal aqueous bolus (8 ml of 5% solution). We have tested the ability of our method to detect the known increase in lung epithelial permeability elicited by challenge of previously sensitized animals with aerosols of Ascaris suum antigen. In Ascaris-sensitive Basenji-Greyhound dogs, antigen challenge significantly increased the rate of appearance and peak plasma level of mannitol after administration of the intratracheal bolus. Peak plasma mannitol levels averaged 25 +/- 3 (SE) micrograms/ml in dogs challenged with Ascaris antigen aerosols, and 14 +/- 2 micrograms/ml in the same animals in separate control experiments employing saline aerosols. The method presented could be readily applied to animal and human studies as a simple, inexpensive, and nontoxic indicator of lung epithelial permeability.

Pruritic dermatitis in asthmatic basenji-greyhound dogs: a model for human atopic dermatitis

A recurrent, nonseasonal pruritic dermatitis manifested as lichenified plaques and as inflammatory nodules and papules in each of fourteen basenji-greyhound (B-G) crossbreed dogs, all of which demonstrated both nonspecific and Ascaris-specific airway hyperreactivity, with changes in pulmonary mechanics of the same order as those seen in symptomatic human asthma. Other features analogous to human atopic disease included blunted cyclic adenosine monophosphate (cAMP) responsiveness to beta adrenergic agents and in vivo release of histamine and slow-reacting substance of anaphylaxis in response to antigen aerosol challenge. The dermatitis appears to be a manifestation of the atopic state in these dogs and may provide an animal model for the study of human atopic dermatitis.

The Basenji-Greyhound dog model of asthma: leukocyte histamine release, serum IgE, and airway response to inhaled antigen

To understand the immunologic mechanisms underlying the variation in airway response to inhaled Ascaris antigen (AA) in Basenji-Greyhound (BG) dogs having hyperreactive airways, we examined the relationship between leukocyte histamine release, Ascaris-specific serum IgE, changes in pulmonary resistance (RL), and decreases in dynamic compliance (Cdyn). All Ascaris-sensitive BG dogs showing airway responses to AA aerosol challenge exhibited an antigen dose-dependent release of leukocyte histamine, with total leukocyte histamine ranging from 68 to 123 ng/10(7) cells. Airway response to inhaled antigen more closely correlated with antigen dose releasing 50% total leukocyte histamine (RL, r = 0.94); Cdyn, r = 0.82), than with circulating levels of antigen-specific IgE (RL, r = 0.68; Cdyn, r = 0.69). We conclude that the airway response of sensitized BG dogs to AA inhalations is more dependent on factors affecting mediator release from pulmonary sources than circulating specific reaginic antibody.

The Basenji-Greyhound dog model of asthma: leukocyte histamine release, serum IgE, and airway response to inhaled antigen

To understand the immunologic mechanisms underlying the variation in airway response to inhaled Ascaris antigen (AA) in Basenji-Greyhound (BG) dogs having hyperreactive airways, we examined the relationship between leukocyte histamine release, Ascaris-specific serum IgE, changes in pulmonary resistance (RL), and decreases in dynamic compliance (Cdyn). All Ascaris-sensitive BG dogs showing airway responses to AA aerosol challenge exhibited an antigen dose-dependent release of leukocyte histamine, with total leukocyte histamine ranging from 68 to 123 ng/10(7) cells. Airway response to inhaled antigen more closely correlated with antigen dose releasing 50% total leukocyte histamine (RL, r = 0.94); Cdyn, r = 0.82), than with circulating levels of antigen-specific IgE (RL, r = 0.68; Cdyn, r = 0.69). We conclude that the airway response of sensitized BG dogs to AA inhalations is more dependent on factors affecting mediator release from pulmonary sources than circulating specific reaginic antibody.

Differential effect of chronic ethanol administration on rates of protein synthesis on free and membrane-bound polysomes in vivo in rat liver during dependence development

Administration of ethanol thrice daily to rats in amounts sufficient to induce a high degree of physical dependence resulted in a 20% decrease in the rate of protein synthesis on liver membrane-bound polysomes in vivo after 3 days of treatment without affecting the rate on free polysomes. The inhibition was attributable to a decrease in the rate of polypeptide elongation as evidence by comparable decreases in nascent chain synthesis and completed protein release without any change in leucine uptake by liver. Chronic ethanol treatment did not affect the quantity or distribution of free and membrane-bound polysomes, the DNA concentration, or the weight of liver. The inhibition of protein synthesis on membrane-bound polysomes cannot, therefore, be readily ascribed to ethanol-induced nutritional deficiencies or to some nonspecific toxic effect of ethanol.

Changes in in vivo rates of protein synthesis on free and membrane-bound polysomes in rat brain during the development of physical dependence on ethanol and after the withdrawal of ethanol

Administration of ethanol and nutrients to rats thrice daily by gavage for 3 days produced a linear increase in physical dependence during the first 3 days and a 2% increase in body weight. Rates of protein synthesis on free and membrane-bound polysomes in whole brain and in 7 brain regions, comprising the entire brain, were measured in vivo under pool expansion conditions with [3H]leucine at intervals during the development and decay of ethanol dependence. During dependence development there was a progressive decrease in the rate of protein synthesis on free polysomes, but this change was not significant (P less than 0.05) until the third day, and a decrease in the rate on membrane-bound polysomes after 3 days. The inhibition of protein synthesis is attributable to a decreased rate of polypeptide elongation. There was no change in brain weight, DNA content, ribosome content, ribosome distribution of mRNA pool size. There was, however, a decrease in leucine uptake after 3 days. In an attempt to distinguish between the acute effects of ethanol on regional rates of protein synthesis and those changes associated with dependence development, rates were measured 1.5 h after administering a 5 g/kg dose of ethanol to both control and dependent rats. Rates on free polysomes in the hippocampus-amygdala and thalamus-hypothalamus and on membrane-bound polysomes in the cerebellum and hippocampus-amygdala of dependent rats were reduced; however, there was a general reduction in the rates in control rats that may have obscured reductions in other regions from dependent rats. During early withdrawal, 12 h after the last dose of ethanol, there was an increase in the rate of free polysomes in the pons-medulla and striatum-septum and on membrane-bound polysomes in the hippocampus-amygdala, and a decrease in the rate on free polysomes in the cortex and thalamus-hypothalamus and on membrane-bound polysomes in the cortex. After 24 h, there was an increase in the rate on free polysomes in all regions (cerebellum, cortex, mesencephalon, striatum-septum and thalamus-hypothalamus) except the hippocampus-amygdala and pons-medulla and an increase in the rate on membrane-bound polysomes in all regions (cortex, hippocampus-amygdala, mesencephalon, pons-medulla and striatum-septum) except the cerebellum and thalamus-hypothalamus. The possible relationship of these changes to the homeostat hypothesis of ethanol dependence is discussed.

Basenji-greyhound dog model of asthma: pulmonary responses after beta-adrenergic blockade

To understand the mechanism underlying bronchial hyperreactivity in the Basenji-Greyhound (BG) dog, the effects of propranolol (2 mg/kg) and hexamethonium (5 mg/kg) on base-line pulmonary mechanics and on the bronchial response to aerosol challenges of citric acid and methacholine were studied in five BG dogs. Both propranolol and hexamethonium increased base-line pulmonary resistance (RL) from 0.69 +/- 0.05 (means +/- SE) cmH2O.l-1.s to 1.67 +/- 0.10 (P less than 0.05) and 2.22 +/- 0.45 cmH2O.1-1.s (P less than 0.05) and decreased dynamic compliance (Cdyn) from 190 +/- 10 ml/cmH2O to 154 +/- 9 (P less than 0.05) and 140 +/- 9 (P less than 0.05) ml/cmH2O, respectively. Both propranolol and hexamethonium potentiated the pulmonary response to 10% citric acid given for 5 min (P less than 0.05). RL postchallenge was 4.4 +/- 0.23, 8.1 +/- 0.81, and 7.8 +/- 0.31 cmH2O.l-1.s, and Cdyn was 78 +/- 5, 58 +/- 6, and 51 +/- 3 ml/cmH2O in untreated, propranolol-pretreated, and hexamethonium-pretreated animals. In untreated BG dogs, methacholine (0.075 mg/ml) increased RL from 0.94 +/- 0.25 to 2.2 +/- 0.21 cmH2O.l-1.s (234%) and decreased Cdyn from 223 +/- 39 to 141 +/- 14 ml/cmH2O (63%). In the same animals pretreated with propranolol, methacholine (0.075 mg/ml) increased RL from 1.9 +/- 0.66 to 4.8 +/- 1.37 cmH2O.l-1.s (253%) and decreased Cdyn from 144 +/- 35 to 81 +/- 15 ml/cmH2O (56%). We conclude that propranolol produces airway constriction in BG dogs, as in asthmatic humans and that the effects of propranolol on airways in BG dogs are not due to parasympathetic or alpha-adrenergic predominance.

Immunochemical characterization of Lymantri dispar NPV hemagglutinin: protein-carbohydrate interaction

The agglutination of chicken erythrocytes by Lymantria dispar nuclear polyhedrosis virus polyhedrin has been shown to provide specific virus identification. Selected mono- and oligosaccharides, present in blood group substances, were assayed by the Land-steiner hapten inhibition technique for specific inhibition of polyhedrin hemagglutination. N-acetylgalactosamine and N-acetylglucosamine inhibit to the greatest extent; galactosamine, glucosamine and fucose to a lesser extent. The hapten inhibition data suggest that a monosaccharide possessing an equatorial 2-acetamido group interacts most avidly with the polyhedrin-combining site. Bergold demonstrated that the polyhedrin dissociates into six subunits at a pH greater than 10.0. Diafiltration equilibrium and Scatchard analysis indicate that N-acetylgalactosamine binds most avidly to the polyhedrin (Kd = 1.7 X 10(-6)) which contains six available sites, suggesting that one hemagglutination site resides on each subunit. Since virions derived in vivo and polyhedrin are serologically cross-reactive, this protein-carbohydrate interaction may play a role in host infectivity by providing a receptor site for virus attachment to target cells.

[Laboratory diagnosis of liver and biliary tract disease]

Of a greater number of biochemical tests in hepatobiliary diseases by means of methematico-statistical methods (calculation of specificity and sensitiveness, variance analysis, discrimination analysis with following discrimination experiments) the parameters should be established which in a step programme with multivariate observation and non-discriminated approach give the best possible information. The recognition of patients with liver diseases (preliminary diagnostics) is at nearly 94% possible with a scale comprising GOT, AAP, some relevant clinical data (touch findings, jaundice, hepatic skin signs) and the hepatitis B-antigen. In non-discriminated approach according to our findings the following scale should not be trangressed: GPT, GOT (compare preliminary diagnostics), LAP, AP, AAP (compare preliminary diagnostics), cholesterol, TTT, bilirubin, beta-GC. As to aimed questionings the bromsulphalein test belongs to the enlarged basic scale.

[Aminopeptidases in the serum and urine of patients with hyperthyroidism]

In patients with hyperthyroidism the serum activities of the leucine aminopeptidase (LAP) and the alanine aminopeptidase (AAP) as well as the alanine aminopeptidase excretion in the urine were determined. A significantly increased activity of the leucine aminopeptidase in the serum and an increased excretion of alanine aminopeptidase in the urine were found. The AAP in the serum did not show a significant increase of activity. On account of the changes in the serum and in the urine before and during therapy a low-grade participation of the hepatobiliary and renal systems which are clinically not uppermost is to be assumed. Increased excretion of AAP and hyperthyroidism coincide nearly without exception in out patients. Correlation-statistical investigations make it probable to regard the increased excretion of AAP in the urine as an indirect parameter of the peripheral metabolism in hyperthyroidism.

[Studies on the specificity of alanine aminopeptidase and its variants in the serum in hepatobiliary diseases]

After examinations on a mixed number of patients (236 patients) the increases of the activities of the alanine aminopeptidase in the serum with relatively high certainty may be traced back to diseases of the liver and of the bile ducts. The hepatobiliary specifity is disturbed only by generalised dermatological diseases, especially eczemas. Changes in the electrophoretic pattern of the serum alanine aminopeptidase are also relatively specific for diseases or lesions of the hepatobiliary system. In 11 of the 12 anomalous zymograms of the alanine aminopeptidase observed among 236 patients the aimed search resulted in an alteration of the hepatobiliary system.

[The effect of therapeutic gentamycin doses on the enzyme secretion in urine]

8 patients with chronic pyelonephritis were given gentamycin intramuscularly injected in individual dosage during 8-10 days. Here the behaviour of the excretion of protein, alanine aminopeptidase alkaline phosphatase, alpha-glucosidase, gamma-glutamyl transpeptidase and lysozyme with the urine was tested. With the exception of the lysozymuria, which increased only in patients with chronic renal insufficiency, regularly a hyperenzymuria developed. Most distinctly the excretion of the alanine aminopeptidase increased. After initial decrease the excretion of total protein transiently increased after completion of the gentamycin therapy. All the deviations were reversible. From the increased excretion of enzymes may not be concluded to a nephrotoxicity of gentamycin.

[Aminopeptidases in the serum following myocardial infarct]

In 19 patients wiht myocardial infarction during 7 weeks after the onset of the infarction the serum activities of the leucine aminopeptidase (LAP) and of the alanine aminopeptidase (AAP) were determined. Here an increase of the LAP-values with a maximum in the 1st week was found. Apparantly a hypoxic lesion of the hepatocytes is to be regarded as cause for this. In patients with shock symptomatology as well as with heart decompensation the AAP-activities were on the average higher than in the cases with myocardial infarction without these alterations during the whole period of observation. In all myocardial infarctions the AAP-zymograms showed an additional anodic AAP-fraction as it was observed in previous investigations in cholestasis.

[Enzymes in urine following administration of hypertonic solutions]

3 patients with chronic nephropathies were given 20 ml of a diatrizoate-X-ray contrast medium, 500 ml of a 10% mannitol solution and 500 ml of a 10% dextran solution intravenously, and the behaviour of the excretion of protein, alanine aminopeptidase, beta-glucuronidase, aryl sulphatase A and lysozyme with the urine was tested. After application of these substances a transient increase of the excretion of alanine aminopeptidase, aryl sulphatase A and protein takes place. Conspicuous is the temporary decrease of the beta-glucuronidase activity in the urine after application of these hypertonic solutions. As a common cause of these changes alterations of the tubular cell in the sense of an osmotic nephropathy are to be assumed.