Tumor Pigmentation Does Not Affect Light-Activated Belzupacap Sarotalocan Treatment but Influences Macrophage Polarization in a Murine Melanoma Model

Purpose

Pigmentation in uveal melanoma is associated with increased malignancy and is known as a barrier for photodynamic therapy. We investigated the role of pigmentation in tumor behavior and the response to light-activated Belzupacap sarotalocan (Bel-sar) treatment in a pigmented (wild type) and nonpigmented (tyrosinase knock-out [TYR knock-out]) cell line in vitro and in a murine model.

Methods

The B16F10 (TYR knock-out) was developed using CRISPR/Cas9. After the treatment with light-activated Bel-sar, cytotoxicity and exposure of damage-associated molecular patterns (DAMPs) were measured by flow cytometry. Treated tumor cells were co-cultured with bone marrow-derived macrophages (BMDMs) and dendritic cells (DCs) to assess phagocytosis and activation. Both cell lines were injected subcutaneously in syngeneic C57BL/6 mice.

Results

Knock-out of the tyrosinase gene in B16F10 led to loss of pigmentation and immature melanosomes. Pigmented tumors contained more M1 and fewer M2 macrophages compared with amelanotic tumors. Bel-sar treatment induced near complete cell death, accompanied with enhanced exposure of DAMPs in both cell lines, resulting in enhanced phagocytosis of BMDMs and maturation of DCs. Bel-sar treatment induced a shift to M1 macrophages and delayed tumor growth in both in vivo tumor models. Following treatment, especially the pigmented tumors and their draining lymph nodes contained IFN-gamma positive CD8+T cells.

Conclusions

Pigmentation influenced the type of infiltrating macrophages in the tumor, with more M1 macrophages in pigmented tumors. Belzupacap sarotalocan treatment induced immunogenic cell death and tumor growth delay in pigmented as well as in nonpigmented models and stimulated M1 macrophage influx in both models.

In Vitro Testing of the Virus-Like Drug Conjugate Belzupacap Sarotalocan (AU-011) on Uveal Melanoma Suggests BAP1-Related Immunostimulatory Capacity

Purpose

The virus-like drug conjugate belzupacap sarotalocan (AU-011), currently under clinical investigation for first-line treatment of primary uveal melanoma (UM), shows enhanced tumor specificity by targeting heparan sulfate proteoglycans (HSPG). Such a treatment may potentially lead to systemic immune responses. We studied the potential of AU-011 treatment to induce immunogenic cell death as the first step to induce systemic immunity.

Methods

We determined binding and uptake of AU-011 in ten primary and metastatic UM cell lines. The subcellular location of AU-011 was assessed by fluorescence microscopy. Following light activation (wavelength 690 nm) of AU-011, the half-maximal effective concentration (EC50) of AU-011 treatment and exposure of damage-associated molecular patterns (DAMPs) were assessed using flow cytometry. DAMPs were measured by RNAseq.

Results

Fluorescence microscopy revealed most of the AU-011 was present in the cytoplasm. AU-011 binding and uptake by UM cells increased over time, with a lower uptake in BAP1-negative than in BAP1-positive cell lines. AU-011 activation induced cell death across all UM cell lines with EC50 values at picomolar concentrations. The AU-011 concentration and total light dose (J/cm2) were the most important parameters for the observed cytotoxicity. Finally, light-activated AU-011 induced exposure of DAMPs calreticulin (CRT) and HSP90. CRT exposure by light-activated AU-011 as well as CRT RNA exposure were lower in BAP1-negative compared to BAP1-positive UM cell lines.

Conclusions

AU-011 treatment at low picomolar range induces immunogenic cell death in all 10 UM cell lines. The in vitro cytotoxicity was accompanied by exposure of DAMPs (HSP90 and CRT), suggesting AU-011 may contribute to the development of systemic immunity and be a suitable candidate for combination with immunotherapy in vivo. AU-011 treatment was more effective against BAP1-positive cell lines, with a lower EC50 and higher CRT exposure.

Immune checkpoint inhibition combined with targeted therapy using a novel virus-like drug conjugate induces complete responses in a murine model of local and distant tumors

Metastases remain the leading cause of cancer-related death worldwide. Therefore, improving the treatment efficacy against such tumors is essential to enhance patient survival. AU-011 (belzupacap sarotalocan) is a new virus-like drug conjugate which is currently in clinical development for the treatment of small choroidal melanoma and high-risk indeterminate lesions in the eye. Upon light activation, AU-011 induces rapid necrotic cell death which is pro-inflammatory and pro-immunogenic, resulting in an anti-tumor immune response. As AU-011 is known to induce systemic anti-tumor immune responses, we investigated whether this combination therapy would also be effective against distant, untreated tumors, as a model for treating local and distant tumors by abscopal immune effects. We compared the efficacy of combining AU-011 with several different checkpoint blockade antibodies to identify optimal treatment regimens in an in vivo tumor model. We show that AU-011 induces immunogenic cell death through the release and exposure of damage-associated molecular patterns (DAMPs), resulting in the maturation of dendritic cells in vitro. Furthermore, we show that AU-011 accumulates in MC38 tumors over time and that ICI enhances the efficacy of AU-011 against established tumors in mice, resulting in complete responses for specific combinations in all treated animals bearing a single MC38 tumor. Finally, we show that AU-011 and anti-PD-L1/anti-LAG-3 antibody treatment was an optimal combination in an abscopal model, inducing complete responses in approximately 75% of animals. Our data show the feasibility of combining AU-011 with PD-L1 and LAG-3 antibodies for the treatment of primary and distant tumors.

Phase transitions in a programmable quantum spin glass simulator

Understanding magnetic phases in quantum mechanical systems is one of the essential goals in condensed matter physics, and the advent of prototype quantum simulation hardware has provided new tools for experimentally probing such systems. We report on the experimental realization of a quantum simulation of interacting Ising spins on three-dimensional cubic lattices up to dimensions 8 × 8 × 8 on a D-Wave processor (D-Wave Systems, Burnaby, Canada). The ability to control and read out the state of individual spins provides direct access to several order parameters, which we used to determine the lattice's magnetic phases as well as critical disorder and one of its universal exponents. By tuning the degree of disorder and effective transverse magnetic field, we observed phase transitions between a paramagnetic, an antiferromagnetic, and a spin-glass phase.

Evidence for articular cartilage regeneration in MRL/MpJ mice

OBJECTIVE

A major clinical problem in Orthopaedics is the repair of traumatic articular cartilage lesions. The MRL/MpJ strain of mice has the remarkable ability to regenerate ear hole punch wounds seamlessly including the scarless replacement of multiple tissues. The objective of this study was to assess whether articular cartilage defects repair or regenerate in the MRL/MpJ 'healer' strain of mice.

METHOD

Full thickness and partial thickness lesions were introduced into trochlear groove articular cartilage of MRL/MpJ and C57Bl/6 mice, a control strain that does not undergo ear hole regeneration. The wound sites were assessed 6 weeks and 12 weeks post-surgery using a histological scoring scheme and immunohistochemistry for markers of articular cartilage including proteoglycan, collagen II and collagen VI.

RESULTS

The partial thickness lesions did not repair in either strain. However, at both 6 weeks and 12 weeks timepoints the MRL/MpJ mice had a superior healing response of full thickness lesions with abundant chondrocytes and an extracellular matrix rich in proteoglycan, collagen II and collagen VI at the wound site. At the 12 week timepoint the enhanced cartilage healing was restricted to male MRL/MpJ mice. In contrast, the C57Bl/6 control strain produced an extracellular matrix at the wound site that, overall, had significantly less matrix proteoglycan and collagen II.

CONCLUSIONS

Male MRL/MpJ mice appear to possess an intrinsic ability to 'regenerate' articular cartilage. Understanding the biochemical and genetic basis for articular cartilage regeneration may open up new treatment options for traumatic articular cartilage defects.

Factors associated with antimicrobial resistance among clinical isolates of Klebsiella pneumoniae: 1-year survey in a French university hospital

Klebsiella pneumoniae is an opportunistic pathogen responsible for nosocomial infections. Both resistance to multiple antibiotics and the expression of virulence factors are likely to be involved in the physiopathological process. In this study, 227 isolates of K. pneumoniae collected over a 1-year period in a teaching hospital in Clermont-Ferrand, France, were investigated for their antibiotic resistance pattern and the presence of several potential virulence traits. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) indicated that most of the isolates were phylogenetically unrelated. When tested in an in vitro adhesion assay with Int-407 intestinal cells, the median adhesion index was 5.5x10(4) bacteria/cm(2) (range, 2.0x10(2)-3.4x10(5)). Isolates resistant to cefoxitin, chloramphenicol, and quinolones showed significantly lower adhesion indexes. The frequency of mutagenesis conferring resistance to rifampicin was low for most of the isolates. The median mutagenesis frequency was 1.0x10(-8) (range, 2.5x10(-9)-3.2x10(-6)) at 24 h and 1.1x10(-8) (range, 1.8x10(-9)-1.2x10(-5)) at 7 days. In contrast, isolates resistant to cefoxitin, chloramphenicol, and tetracycline showed a significantly greater ability to mutate. These results suggest a link between adhesion capabilities and resistance to certain antibiotics. They furthermore indicate that strains with a high mutagenesis capacity are more likely to acquire antibiotic resistance genes. The high pathogenicity island of Yersinia was detected in 16.3% of the strains and was more often associated with isolates resistant to nalidixic acid and augmentin.

Submaximal motor unit firing rates after 8 wk of isometric resistance training

PURPOSE

The purpose of this study was to test the hypothesis that average motor unit firing rates change in parallel with the contractile properties of vastus lateralis following 8 wk of isometric resistance training.

METHODS

The firing rates from more than 400 motor units of vastus lateralis were obtained during voluntary isometric contractions of 50% MVC, before and again after training in male subjects (N = 10) and their untrained controls (N = 10). Single motor unit spike trains were recorded with tungsten microelectrodes.

RESULTS

Training resulted in a 36% (P < 0.05) increase in MVC. We also found significant increases (P < 0.05) in maximal twitch amplitude (+17%), time to peak tension (+9%) and the maximal instantaneous rate of contraction (+20%) in the trained leg of the experimental group. Neither the maximal integrated EMG nor the rate of increase of integrated EMG was different after training. There were no significant changes in any of these measures from the untrained leg or the control group. Average firing rates were not different after training despite the increase in twitch contractile speed.

CONCLUSION

These findings suggest that the control properties of the nervous system are not altered despite sizable changes in the contractile properties of muscle following 8 wk of resistance training.

Characterization of enteroaggregative Escherichia coli isolates

Forty enteraggregative Escherichia coli (EAggEC) previously characterized by their ability to adhere to HEp-2 cells or/and their hybridization with the 1-kb EAggEC DNA probe were investigated for the presence of adherence factors and heat-stable enterotoxin (EAST1)-encoding genes. Only 45% of the isolates harbored the EAST1-encoding genes as detected by polymerase chain reaction. None of them hybridized with an AAF/II-encoding gene specific DNA probe and 35% (14/40) were positive in a PCR assay using primers specific for aggC, an accessory gene of the AAF/I-encoding operon. Cloning and sequence analysis of the aggA variant from one isolate, EAggEC 457, revealed 68.9% identity between its deduced amino acid sequence and those of the aggA product from the AAF/I-producing reference strain, E. coli 17.2. No major protein subunit was detected at the surface of EAggEC 457 compared to the bacterial surface extract of E. coli 17.2.

Non-O157:H7 Stx2-producing Escherichia coli strains associated with sporadic cases of hemolytic-uremic syndrome in adults

From August 1996 to May 1997, six verotoxin-producing Escherichia coli (VTEC) strains were isolated from stool specimens of adults suffering from hemolytic-uremic syndrome (HUS). All the isolates were stx2 positive and belonged to different serotypes: O6:H4, O91:H10, O91:H21, O rough:H16, OX3:H-, and O nontypeable: H-. The enterohemolysin (Ehly)-encoding genes were detected in two isolates, and none of the isolates harbors the intimin (Eae)-encoding gene. These findings suggest that stx2-positive non-O157:H7 VTEC is a major cause of HUS in adults and that several sources of pathogens are responsible for local endemic infections.

Probabilities associated with counting average motor unit firing rates in active human muscle

Motor unit firing rates in human muscle can be determined from recordings made with small-diameter microelectrodes inserted directly into the muscle during voluntary contraction. Frequently, these counts are pooled to give an average motor unit firing rate under a given set of conditions. Since the fibers of one motor unit are dispersed among the cells of several others, it is conceivable that discharge rates can be measured in more than one cell from the same unit. If this occurred frequently, the distribution of firing rates could be influenced by those from units counted more than once. Based on literature values, we made the following assumptions: vastus lateralis contains approximately 300 motor units, with an average innervation ratio of 1500. Muscle cell diameter is about 50 to 100 microns and cells are randomly distributed over a motor unit territory of 10 microns diameter. The recording range of a microelectrode is about 600 microns. Given the distribution of cells normally found in whole human muscle, the probability of recording from two or more cells of the same motor unit at 50% MVC follows a Poisson distribution with a mean of 0.44. This model suggests that although there is a low probability of some duplication in this technique, the extent to which it influences the distribution of average motor unit firing rates is minimal over the entire range of forces produced by vastus lateralis.

Relationship between adhesion to intestinal Caco-2 cells and multidrug resistance in Klebsiella pneumoniae clinical isolates

Klebsiella pneumoniae is an opportunistic gram-negative pathogen involved in outbreaks of nosocomial infections in intensive care units. Strains are resistant to multiple antibiotics, and 15 to 30% of them are also resistant to the broad-spectrum cephalosporins by the production of R plasmid-encoded extended-spectrum beta-lactamases. Because the gastrointestinal tracts of patients have been shown to be the reservoir for nosocomial strains of K. pneumoniae, we looked for a correlation between antibiotic resistance and adhesion of K. pneumoniae strains to intestinal cells. We investigated adhesion to the human intestinal epithelial Caco-2 cell line of 61 clinical K. pneumoniae strains isolated in hospitals in Clermont-Ferrand, France. None of the strains tested expressed the previously described adhesive factors CF29K and KPF-28. Adhesive properties were found for 42.6% of the strains tested (26 strains). Just 7.7% (2 strains) of the 26 strains producing only the chromosomally encoded SHV-1 beta-lactamase adhered to the Caco-2 cell line, whereas 68.5% (24 strains) of the 35 strains producing a plasmid-encoded beta-lactamase were adherent. All the adherent strains, and even the two strains producing only the SHV-1 enzyme, harbored at least one self-transmissible R plasmid. At variance for CAZ-1/TEM-5 or CAZ-5/SHV-4 beta-lactamase-producing K. pneumoniae strains, curing and mating experiments demonstrated that the self-transmissible R plasmids encoding the TEM-1, CTX-1/TEM-3, CAZ-2/TEM-8, CAZ-6/TEM-24, or CAZ-7/TEM-16 beta-lactamase were not involved in the adhesion of K. pneumoniae strains to intestinal epithelial cells. Nevertheless, there was an association of multiple antibiotic resistance, including resistance to extended-spectrum cephalosporins, and adhesive properties in K. pneumoniae clinical isolates.

Enteroadherent Escherichia coli and diarrhea in children: a prospective case-control study

The relative contribution of diarrheagenic Escherichia coli was examined during a 1-year prospective study of hospitalized children in Clermont-Ferrand, France, including 220 case patients (with diarrhea) and 211 matched controls. Fecal isolates were characterized by means of their pattern of adherence to HEp-2 cells and by colony hybridization with DNA probes specific for the six categories of diarrheagenic E. coli. No enteroinvasive or enterotoxigenic E. coli isolates were isolated. Twenty-eight (6.5%) eae-positive isolates and 39 (9%) enteroaggregative E. coli isolates characterized with the aggregative adherence probe and/or by their adherence pattern were detected; they were equally distributed among the patients and the controls. Diffusely adhering E. coli was the predominant pathotype: 30.7% were detected by their adherence pattern and 13.7% were detected with the daaC probe. They were isolated with similar frequencies from the patients and the controls, thereby showing no association with diarrhea. However, daaC-positive strains were significantly associated with a past record of urinary tract infections. These results suggest that the diffusely adhering E. coli organisms isolated in the present study are not true intestinal pathogens but may be regarded as resident colonic strains.

Observer sensitivity to retinal vessel diameter and tortuosity in retinopathy of prematurity: a model system

BACKGROUND

Abnormally increased diameter and tortuosity of retinal blood vessels in the posterior pole, or "plus disease," is recognized as a powerful predictor of poor outcome in eyes with retinopathy of prematurity (ROP). Although the diagnosis of plus disease depends upon the examiner's ability to examine retinal blood vessels, the ability of the human observer to identify changes in retinal blood vessel diameter and tortuosity accurately has not been studied.

METHODS

Using computer-aided analysis of fundus photographs from eyes with a wide range of ROP severity, we generated tracings of posterior pole blood vessels which varied by quintiles of mean vessel diameter and tortuosity. Subjects (23 naive and 12 expert observers) ranked groups of tracings in order of increasing mean vessel diameter and tortuosity. These ranking tests were performed on tracings derived from the same fundus and tracings derived from distinct fundi. In a similar fashion, subjects also compared one designated standard fundus tracing with 25 distinct fundus tracings.

RESULTS

Vessel diameter was assessed correctly more often than vessel tortuosity, both among similar (> 99% vs 92% of the time, respectively, P < 0.001), or among distinct (88% vs 78% of the time, respectively, P < 0.001) fundus images. The mean vessel diameter and tortuosity of 25 distinct fundus images were correctly ranked versus a standard image in 89% of attempts. Assessments of increments in vessel diameter and tortuosity were independent. Naive and expert subjects performed indistinguishably on all tests.

CONCLUSIONS

Intelligent human observers have considerable ability to discern clinically relevant increments in blood vessel diameter and tortuosity. This ability may facilitate standardization in the diagnosis of plus disease in ROP.

Temporary vessel occlusion for aneurysm surgery: risk factors for stroke in patients protected by induced hypothermia and hypertension and intravenous mannitol administration

Temporary vessel occlusion is an effective technique used by microvascular surgeons to facilitate dissection and permanent clipping of cerebral aneurysms; however, several questions remain regarding the overall safety of this technique. To identify technical and patient-specific risk factors for perioperative stroke, the authors examined a series of patients in whom induced hypertension and mild hypothermia and intravenous mannitol administration were used as protection during temporary vessel occlusion for aneurysm clipping. The study comprises a nonconcurrent prospective analysis of 132 consecutive aneurysm clippings performed with the aid of temporary vascular occlusion and a specific antiischemic anesthetic protocol at the Massachusetts General Hospital from 1991 to 1993. Factors studied included duration of the temporary clip application, number of occlusive episodes, patient age and neurological status, presence of preoperative subarachnoid hemorrhage (SAH), and intraoperative aneurysm rupture ("forced" temporary clipping), as well as whether proximal vessel occlusion or complete aneurysm trapping was used. In a univariate analysis, patient age, intraoperative aneurysm rupture, temporary clipping lasting more than 20 minutes, clipping between the 4th and 10th day after SAH, and multiple clipping episodes were all significantly associated with stroke outcome. Multivariate logistic regression revealed that intraoperative aneurysm rupture (relative risk 5.6, p = 0.02) and a duration of temporary clip application that lasted more than 20 minutes (relative risk 9.4, p = 0.04) were independently associated with stroke outcome. Overall, 5.2% of the patients had postoperative clinical strokes. Based on their findings the authors conclude that temporary clipping is a safe adjunct to aneurysm surgery, particularly when the duration of clipping is short.

Experimental evaluation of a hydroxylapatite reservoir tube shunt in rabbits

BACKGROUND AND OBJECTIVES

Anterior chamber tube shunts of various design are of increasing importance in the surgical management of refractory glaucoma. However, the reservoirs that are commonly used today are made of a silicone or an acrylic material that may become enveloped by a fibrous capsule, which in turn may impede aqueous resorption. In this study, the authors investigated the properties of hydroxylapatite (HA) as a reservoir in gonioimplants, using three different types of HA reservoir designs. It has been demonstrated that HA orbital implants become vascularized, and the authors hypothesized that this feature of HA might modify the development of the fibrous capsule, enhancing the efficacy and decreasing the size of the implants.

MATERIALS AND METHODS

HA reservoirs with Silastic tube shunts were implanted in the right eyes of six Dutch-belted rabbits. Clinical examinations were performed and intraocular pressure was measured periodically for 16 weeks postoperatively. Prior to euthanasia, fluorescein-labeled latex microspheres were injected into the anterior chamber to demonstrate implant patency. Light microscopy was used to study the tissue response to the implants and the pathways of aqueous flow.

RESULTS

In general, the authors found a granulomatous inflammatory response to the HA accompanied by neovascularization into the implant and minimal fibrous encapsulation of the reservoir.

CONCLUSIONS

The use of HA as a suprascleral reservoir has several advantages, the major one being a theoretical increase in the functional lifetime of the implant.

Retrospective case-control study of diffusely adhering Escherichia coli and clinical features in children with diarrhea

A retrospective case-control study with a small population group revealed that, among clinical signs, vomiting but not diarrhea was significantly associated with the presence of diffusely adhering Escherichia coli (DAEC) in children suffering from gastroenteritidis (P < 0.05). Of the children carrying DAEC strains, those who were F1845 DNA probe positive had a significantly longer hospital stay than those who were F1845 DNA probe negative. We believe that the heterogeneity of DAEC strains is responsible for the discrepant results concerning their involvement in disease and that only some of these strains are really pathogenic for children.

Survey of clinical isolates of diarrhoeogenic Escherichia coli: diffusely adhering E. coli strains with multiple adhesive factors

A total of 335 Escherichia coli strains were isolated from sporadic cases of aqueous diarrhoea in patients hospitalized in Clermont-Ferrand, France, during 1991 and 1992. Many of these strains belonged to the diffusely adhering E. coli (DAEC) group, since 51 of them (15.2%) hybridized with the daaC probe corresponding to the accessory gene of the F1845 adhesin and 13 (3.9%) with the AIDA-I (adhesin involved in diffuse adhesion-I) structural gene. The other pathogenic E. coli groups were weakly represented: 0.6% (2 strains) of enterotoxigenic E. coli (ETEC), 0.6% (2 strains) of enterohaemorrhagic E. coli (EHEC) and 3.9% (13 strains) of enteroaggregative E. coli (EAggEC). Neither enteropathogenic E. coli (EPEC) nor enteroinvasive E. coli (EIEC) were isolated in our study period. Among the DAEC strains studied, we described two major surface proteins of 16 and 29 kDa. We showed that the 16-kDa protein (CF16K) was involved in adhesion in vitro to Caco-2 and HEp-2 cells. Pretreatment of bacteria with anti-CF16K serum or of Caco-2 cells with purified CF16K greatly decreased the adhesion of the E. coli CF1085 strain producing the CF16K protein to both cell types. The CF16K adhesive factor was found in 9.5% (33 strains) of the 335 E. coli strains studied by colony immunoblot assays with anti-CF16K serum. Twelve strains producing CF16K hybridized with the daaC probe, indicating that the CF16K is not related to the Dr family adhesins which recognized the Dr blood group antigen as receptor. The 29-kDa protein, isolated from 9 strains out of the 335 studied (5.1%), was identified as the CS31A antigen by Western blot assay using anti-CS31A serum and by hybridization experiments with a CS31A DNA probe. This antigen is routinely observed in septicaemic or enterotoxigenic bovine E. coli strains. We showed that a single diarrhoeogenic E. coli strain could harbour at least two adhesive factors, since 36% of CF16K E. coli strain producers and 68.4% of CS31A E. coli strain producers hybridized with the daaC DNA probe.

Six-month stability of psychiatric diagnoses in first-admission patients with psychosis

OBJECTIVE

The short-term diagnostic stability of schizophrenic and other psychotic disorders was examined in first-admission patients, with attention to the principal reasons for diagnostic change.

METHOD

Hospitalized first-admission patients (N = 278) participating in an epidemiologic study were interviewed at baseline and after 6 months with the Structured Clinical Interview for DSM-III-R. A best estimate diagnosis was made at both time points with the use of all available sources of information. Reasons for changes in diagnosis were determined by two psychiatrists.

RESULTS

Affective psychosis and schizophrenic disorders were relatively stable broad diagnostic categories over the 6-month period, with 86.5%-88.9% of the patients remaining in the same category, although findings for specific diagnoses within these categories ranged from 61.5% to 85.7%. The groups with unknown and nonspecific diagnoses showed less stability; the diagnoses of more than one-third of these patients remained unknown or nonspecific at the 6-month evaluation. If the 6-month diagnoses are used as the research standard, somewhat lower percentages of patients received the same diagnoses at baseline. Forty-three percent of the changes in diagnosis were attributed to the clinical course of illness; the rest were attributed to the diagnostic process itself.

CONCLUSIONS

A longitudinal diagnostic assessment based on multiple sources of information is crucial for categorizing first-admission psychotic patients, particularly those who do not initially fit into a DSM-III-R category. The short-term stability of a diagnosis is a function of multiple factors, including the changing clinical picture, additional sources of information, and new interpretations of original data.

Self-transmissible R plasmids encoding CS31A among human Escherichia coli strains isolated from diarrheal stools

The CS31A antigen was first described for septicemic and enterotoxigenic bovine E. coli strains. In our study, of 597 human Escherichia coli strains isolated from diarrheagenic stools of hospitalized patients, 30 (5%) hybridized with the CS31A DNA probe. These CS31A-positive E. coli strains diffusely adhered to Caco-2 and/or HEp-2 cells and produced a major surface protein of either 30 or 30.5 kDa according to the strain. These proteins were antigenically related to the two forms of the CS31A antigen, namely, CS31A-L and CS31A-H. Genes encoding CS31A were located on 140-kb conjugative R plasmids. E. coli transconjugants expressed major surface proteins similar to those of the wild-type strains and adhered to Caco-2 and/or HEp-2 cells. An association of CS31A and another adhesive factor of the Dr family was found in 70% of wild-type strains, since 21 strains hybridized with the diffuse adhesion DNA probe corresponding to the accessory gene (daaC) of the F1845 adhesin. Comparison of the restriction patterns of the 140-kb R plasmids of the CS31A-positive E. coli strains showed these plasmids to be similar. Hybridization experiments indicated that the genes encoding CS31A and resistance to penicillin were located together on either of two 20- or 27-kb EcoRI restriction fragments in four E. coli strains. We reported a similar linkage between these genes in Klebsiella pneumoniae strains which produced CF29K, a CS31A-like antigen. These results suggest a horizontal transfer between E. coli and K. pneumoniae strains.

Deferred compensation for tax-exempt entities

Many executives in tax-exempt organizations, including healthcare executives, find their tax-advantaged savings opportunities dramatically reduced today compared to previous years. The benefit of employer-sponsored, "qualified" retirement and savings programs has been severely limited by ever-increasing tax restrictions on such plans when they are offered by tax-exempt organizations. And the opportunity for tax-sheltered personal investments has virtually disappeared. One of the last remaining opportunities for tax-advantaged savings in tax-exempt organizations is an employer-sponsored, non-qualified, deferred compensation plan, an option that appears increasingly attractive in light of the recently enacted increased personal tax rates.

Escherichia coli strains involved in diarrhea in France: high prevalence and heterogeneity of diffusely adhering strains

Two hundred sixty-two strains of Escherichia coli isolated from diarrheal stool specimens from infants, children, and adults hospitalized in Clermont-Ferrand, France, were studied to classify them in the previously described pathogenic groups of E. coli involved in diarrheal diseases. A total of 1.5% of them belonged to the enterotoxigenic E. coli pathotype, but none belonged to the enteroinvasive E. coli, enterohemorrhagic E. coli, or enteropathogenic E. coli pathotypes. Seventeen strains (6.5%) exhibited an aggregative pattern of adhesion to HEp-2 cells (EAggEC pathotype), but of these, three (17.6%) did not hybridize with the EAggEC DNA probe. Most of the strains involved in diarrhea belonged to the diffusely adhering E. coli group; 100 strains (38.2%) exhibited a diffuse adhesion (DA) to HEp-2 cells. Only eight strains (8.9%) from controls diffusely adhered to HEp-2 cells. The highly significant difference (P < 0.0001) between DA strains from patients and from controls suggests that the diffusely adhering E. coli strains should be considered pathogens. Only 33 of them (33%) hybridized with the previously described DA DNA probe, and only 2 (2%) hybridized with the AIDA DNA probe. Four different major proteins were observed in the bacterial surface extracts of the 33 strains positive with the DA DNA probe. In addition, 16 strains that diffusely adhered to HEp-2 cells induced a cytotoxic effect on HEp-2 cells that was characterized by pyknosis and lysis of the cytoplasmic membrane. This cytotoxic effect was correlated with the synthesis of a hemolysin. The genes involved in diffuse adhesion to HEp-2 cells were located on conjugative R plasmids in strains that did not hybridize with the DA or AIDA DNA probes.

An unusual cause of cerebral venous thrombosis in a four-year-old child

BACKGROUND AND PURPOSE

Inherited protein S deficiency has been associated with an increased risk of thromboembolic disease. It is possible that such a coagulopathy could predispose children to the development of strokes by permitting clot formation in response to stimuli that ordinarily would be insufficient to cause thrombus formation.

CASE DESCRIPTION

We evaluated a previously well 4-year-old boy who developed cerebral venous thrombosis after suffering minor head trauma. Crossed-immunoelectrophoresis of his plasma showed a marked decrease of the free, active form of protein S. Family studies revealed that the patient's father and other paternal relatives had a similar abnormality of protein S.

CONCLUSIONS

We suggest that the cerebral venous thrombosis in this child was initially precipitated by minor head trauma and pathological thrombus formation was then potentiated by inherited protein S deficiency. This case extends the clinical spectrum for protein S deficiency and emphasizes the importance of evaluating family members to establish a specific diagnosis and therapeutic intervention.

R-plasmid-encoded adhesive factor in Klebsiella pneumoniae strains responsible for human nosocomial infections

Klebsiella pneumoniae strains involved in hospital outbreaks of nosocomial infections, such as suppurative lesions, bacteremia, and septicemia, were resistant to multiple antibiotics including broad-spectrum cephalosporins. Epidemiologic investigations revealed that the reservoir for these K. pneumoniae strains was the gastrointestinal tracts of the patients. The study of the adherence ability of the strains reported here showed that these bacteria adhered to the microvilli of the Caco-2 cell line. This adhesion was mediated by a nonfimbrial protein with a molecular mass of 29,000 Da designated CF29K. Pretreatment of bacteria with antibodies raised against CF29K or Caco-2 cells with purified CF29K prevented the adhesion of K. pneumoniae strains to Caco-2 cells. CF29K immunologically cross-reacted with the CS31A surface protein of Escherichia coli strains involved in septicemia in calves. Genes encoding CF29K were located on a high-molecular-weight conjugative R plasmid, which transferred to E. coli K-12. Transconjugants expressed a large amount of CF29K protein and adhered to the brush border of Caco-2 cells. These findings show that K. pneumoniae strains were able to colonize the human intestinal tract through a plasmid-encoded 29,000-Da surface protein. Hybridization experiments indicated that the gene encoding resistance to broad-spectrum cephalosporins by the production of CAZ-1 enzyme and the gene encoding the adhesive property to intestinal cells were both located on a 20- to 22-kb EcoRI restriction DNA fragment. Genes encoding aerobactin and the ferric aerobactin receptor were also found on this R plasmid.

[Factors intervening in the variations of in vitro adhesion power of enterotoxinogenic colibacillus (ETEC) to human enterocytes]

Human enterotoxigenic Escherichia coli adhere to the brush border of human enterocytes. The mean number of bacteria adhering to one enterocyte (adhesion index) varied from 0.5 to 3.1 when the strains produce adhesins. Different factors related to enterocytes and to bacteria are involved in this variability. The number of bacteria which adhered to enterocytes issued from the same donor varied from from 0 to 12. Moreover the proportion of enterocytes on which several bacteria sticked did not exceed 20%. This variability might be due to the disparity in the maturation of the enterocytes. On the other hand, whatever the adhesion factors considered, the adhesion index varied according to the donors. ETEC strains did not express adhesion when bacteria were grown in a liquid medium but this capacity could be restored after transfer on solid medium. This phenomenon seemed like a phase-variation and appeared to be linked to a 4 to 6 kilobases (kb) plasmid. On the other hand, when the bacteria were grown on agar medium (CFA-agar or Mueller-Hinton agar) two phenotypes of colonies could be observed: large colonies (LC) which were composed of non-adhesive bacteria and small colonies (SC) which were composed of a majority of adhesive bacteria; when the number of subcultures was not too great, a majority of colonies presented the small colonies phenotype. The plasmid content analysis showed the segregation of a high molecular weight plasmid DNA (approximately 100 kb) for the bacteria issued from large colonies phenotype.

Peri-operative colonoscopy detects synchronous tumours in patients with colorectal cancers

The aim of this study was to assess the value of colonoscopy as a peri-operative investigation in patients treated for colorectal cancer by surgical excision. Patients (134 male, 83 female) undergoing curative resection for colorectal carcinoma between August 1984 and January 1989 had colonoscopy within 3 months of surgery. Eleven patients (5%) had a synchronous cancer, which was diagnosed by colonoscopy in eight. In six of these eight, the diagnosis was made after surgery and 3 patients needed a second colectomy. However, in 3 patients the synchronous cancer was removed endoscopically without the need for further surgical resection. Most synchronous cancers had an earlier pathological stage than the index tumour. The rate of synchronous cancers was higher in patients with synchronous benign polyps (16%) than in those without polyps (3%). Colonoscopy is clearly justified as a peri-operative investigation in all patients undergoing potentially curative resection of colorectal cancer. If possible, the examination should be carried out prior to surgery, to guide the extent of resection.

Adhesion of enterotoxigenic Escherichia coli to the human colon carcinoma cell line Caco-2 in culture

Enterotoxigenic Escherichia coli (ETEC) strains possessing colonization factor antigen I (CFA/I), CFA/II, CFA/III, and antigen 2230 were tested for their ability to adhere to the following cell lines: HeLa, HEp-2, HRT 18, Hutu 80, MDBK, MDCK, Vero, and Caco-2. ETEC strains adhered only to the Caco-2 cell line. Irrespective of the known adhesive factors, the ETEC strains that adhered to the brush border of human enterocytes also adhered to the Caco-2 cell line. The negative variants, which were cured of the plasmid encoding the adhesive factor, did not adhere. Adhesion of ETEC strains no longer occurred when the Caco-2 cells were pretreated with the homologous colonization factor antigen or when the bacterial cells were pretreated with homologous antibodies raised against the adhesive factors. This indicates that this adhesion is specific and that a different receptor exists for each type of adhesion factor. Electron micrographs of cross sections of the monolayer showed that the adhesion of ETEC strains to the brush border microvilli does not induce any lesion. Therefore, the Caco-2 cell line behaves in the same way as human enterocytes do.

[Inhibition by nifurzide of the adhesion capacity of enteropathogenic colibacillus to HEP-2 cells]

Enteropathogenic Escherichia coli (EPEC) adhere in vivo to enterocytes. This adhesion capacity can be obtained in vitro with Hep-2 cells on which a characteristic localized adherence (LA) is observed. We studied the effect of subinhibitory concentrations (SIC) of nifurzide, a nitrofurane derivative, on this bacterial adherence phenomenon. Three EPEC strains are used: 11201 (026 serogroup), 7958 (0128) and 7836 (0142). Various SIC (MIC/2; MIC/4;...; MIC/32) were added either to the culture medium of bacteria or to the Eagle medium in which bacteria and Hep-2 cells were mixed during the adhesion experiments. In each case an adhesion index is determined. Nifurzide strongly inhibits the adherence capacity of the three strains when concentrations ranging from MIC/2 to MIC/16 where added in both culture media. On the other hand three other nitrofurane derivatives which have no antibacterial effect did not inhibit adherence. The mechanism of the adherence inhibition by nifurzide is discussed.

Adhesive properties of enteropathogenic Escherichia coli isolated from infants with acute diarrhea in Africa

The adhesive properties of 69 enteropathogenic Escherichia coli (EPEC) strains were studied. The strains were isolated from diarrheal stools of infants in Burundi, Africa, and identified by serotyping with 12 classical EPEC O serogroup antisera. A test for adhesion to HEp-2 cells revealed that 52% of the strains showed localized adherence and 13% diffuse adherence. Localized adherence phenotype was found in previously described serogroups O86, O111, O125, O127, O128 and O142; strains belonging to another serogroup, O126, also exhibited localized adherence. Use of an EPEC adherence factor DNA probe in colony hybridization and in Southern blot techniques revealed that all strains exhibiting localized adherence and no strain exhibiting diffuse adherence produced a positive reaction; the genes were localized on high molecular weight plasmids (50-70 megadaltons). In vitro adhesion tests with human enterocytes performed concurrently with all 69 strains showed that only six of them adhered. These strains belonged to the O26, O117, O125, O128 and O142 serogroups. The adhesin CFA/I was detected only in the O128 Escherichia coli. The strain of serogroup O142 exhibited both adhesion to human enterocytes and localized adherence to HEp-2 cells, which suggests that the adhesive systems of enterotoxigenic and enteropathogenic Escherichia coli may coexist.

Characterization of Haemophilus influenzae isolated from patients with otitis media

Two hundred and twenty-three Haemophilus influenzae strains isolated from patients with otitis media throughout France were characterized by biotype, serotype, antibiotic susceptibility, type of beta-lactamase production and human erythrocyte agglutination properties. All strains fell in one of two groups. One group consisted of encapsulated type b strains, 50% of which were biotype I, often resistant to ampicillin (38.5% of beta-lactamase producing strains) and seldom positive for haemagglutination (3.8%). The second group was composed of non-encapsulated strains, 42% of which were of biotype II, 10.6% beta-lactamase producers and 10.5% positive for haemagglutination.

Gestational diabetes mellitus is associated with HLA-DQ beta-chain DNA endonuclease fragments

DNA from Caucasian normal healthy control subjects, non-gravid patients with insulin-dependent diabetes mellitus (IDDM) and gravida with gestational diabetes mellitus (GDM) were analyzed with DNA probes for HLA markers associated with HLA-DR and HLA-DQ to compare the hybridization patterns of their DNA after digestion with restriction endonucleases. We report HLA-DQ beta restriction endonuclease fragments to be presented with increased frequency in Caucasian gravida with GDM as well as in subjects with IDDM. These findings provide further evidence for genetic heterogeneity in GDM and are compatible with the presence of slowly evolving IDDM in some women with "carbohydrate intolerance of variable severity with onset or first recognition during pregnancy".

Tibial plateau fractures

Certain factors in tibial plateau fractures that lead to increased disability may be avoided by following the objectives of articular surface restoration, good internal fixation, early knee motion, strengthening exercises, and soft-tissue repair. In some types of fractures, traumatic arthritis may be unavoidable.

Molecular biology of the HLA system in insulin-dependent diabetes mellitus

Genetic studies indicate that the IDDM susceptibility genes in the HLA region are closely linked to the DR3 and DR4 specificities; however, these specificities do not define the actual susceptibility genes. Molecular studies confirm this hypothesis by demonstrating restriction fragment length polymorphism between DNA's of identical DR specificities and thereby separating the DR haplotypes into those strongly or weakly associated with IDDM. Further studies at the nucleotide sequence level demonstrate further heterogeneity, with DR4 being associated with at least three different DQ beta genes and five different genes of the DR beta-1 locus. However, the majority of these subtypes are now recognized either serologically or by T-cell responses in mixed lymphocyte cultures. Furthermore, the sequences associated with IDDM are those most commonly found in DR4 individuals, ie, Dw4 and DQw3.2. Clearly, these and other class II genes must be studied for additional DNA polymorphism and their relevance for IDDM. For example, the DX alpha, 2.1-kb Taql polymorphism shows a stronger correlation with IDDM than DR3. However, it is not even known if the DX alpha genes are expressed. In addition, little is known of the DQ beta and DR beta genes associated with different DR3-associated haplotypes. Furthermore, an IDDM susceptibility gene may contain important differences in flanking or intron sequences controlling expression of these genes. The methods of recombinant DNA technology are enabling these unanswered questions to be addressed.

Multiplicity of serogroups and adhesins in enteropathogenic and enterotoxigenic Escherichia coli isolated from acute diarrhea in Senegal

Escherichia coli strains were isolated from 228 children with diarrhea in Senegal from 1982 to 1984. Among these E. coli involved in cases of diarrhea, we found that 20.3% were enteropathogenic E. coli. Only 3.9% of the strains adhered to the brush borders of human intestinal enterocytes, and they belonged to different serotypes. All these adhesion-positive strains possessed genes encoding for the heat-stable enterotoxin, but their adhesive factors were different regarding serology with anti-colonization factor sera, hemagglutination patterns, electron microscopy structures, or major surface protein subunits.

Zone approach to knee arthroscopy

The zone approach to knee arthroscopy divides the knee into ten anatomic zones. This article presents the zone classifications and describes the combination of portals for the arthroscope, the probe, and the operating instruments. The particular leg position which is thought to allow the best visualization of each zone is also described. Alternate portals are necessary in certain situations, as in knees with tight ligamentous structures. This list of standard and alternate portals is not meant to be all-inclusive, but we do urge that all ten zones are examined during arthroscopy. The objectives of this article are to describe a method of arthroscopic examination that is both systematic and comprehensive, and to develop an arthroscopic nomenclature that allows easy localization and reporting of pathology in the knee joint.

Characterization of three HLA-DR beta genes isolated from an HLA-DR 3/4 insulin-dependent diabetic patient

Three HLA-DR beta genes were isolated from a Swedish HLA-DR3/4 insulin-dependent diabetes mellitus (IDDM) patient and characterized by restriction endonuclease mapping and nucleotide sequence analysis. Two out of the three DNA sequences differed from those of published DR beta-chain sequences. A DR beta-gene probe prepared from exon 4 and flanking sequences was used in a Southern blot analysis of blood donors' DNA and DNA from HLA-DR3/4 IDDM patients and HLA-DR-matched healthy control subjects. This probe differentiated HLA-DR3/4 IDDM patients and HLA-DR-matched controls in the Scandinavian population but not in the North American Caucasoid population.

Cerebellar syndrome following neuroleptic induced heat stroke

We report a patient in whom extreme hyperthermia, rhabdomyolysis, acute renal failure and a residual pancerebellar syndrome occurred while taking a combination of perphenazine and amitriptyline. We postulate that impaired thermoregulation due to psychotropic drugs was responsible for the development of heat stroke and that the cerebellar syndrome resulted directly from the elevated temperature.