CHANGES IN THE VISION OF ADULT AMBLYOPIC PATIENTS FOLLOWING CLEAR LENS EXTRACTION.

AIMS: The aim of the study was to retrospectively evaluate changes in vision after the implantation of trifocal (tIOL) or rotationally asymmetric multifocal artificial intraocular lenses (mIOL) in patients undergoing clear lens extraction. The main goal was to determine whether changes to central visual acuity occur after the implantation of an IOL at a follow-up examination after one year. Other objectives were to determine the difference between the groups with implanted diffractive and rotationally asymmetric artificial intraocular lenses, as well as to evaluate the risk of accurate correction in patients who had lived most of their lives "undercorrected". MATERIAL AND METHODS: In our study, we present a retrospective longitudinal evaluation of results in patients after the implantation of an artificial intraocular lens. In the period from 2013 to 2020, we evaluated changes in the vision of 22 patients aged 39-59 years, of whom 18 were women and 5 were men. The average preoperative refraction of myopic eyes was +5.7 ±2.13 Dsf and +1.24 ±0.86 Dcyl. In amblyopic eyes, 7 diffractive lenses and 15 rotationally asymmetric lenses were used. RESULTS: Uncorrected distance visual acuity before surgery and one year (1Y) after was 0.13 ±0.09 vs. 0.57 ±0.28 (p < 0.001); the best corrected distance visual acuity before and 1Y after was 0.53 ±0.22 vs. 0.62 ±0.29 (p = 0.024); uncorrected near visual acuity before and 1Y after was 0.06 ±0.06 vs. 0.48 ±0.32 (p < 0.001); the best corrected near visual acuity before and afér the surgical procedure was 0.45 ±0.27vs. 0.55 ±0.35 (p = 0.014). CONCLUSION: Implantation of tIOL and mIOL lenses was effective in our group of patients with amblyopia, thus improving uncorrected distance and near visual acuity and without serious adverse effects. At the same time, we evaluate that the change in refraction and the removal of anisometropia lead to a significant change in the best corrected visual acuity for distance or near vision at the one-year follow-up examination.

Desarrollo y validación de una escala de actitudes hacia la discapacidad en personal militar / Development and validation of an attitudes scale towards disability in military personnel

Antecedentes y objetivo: La concepción actual de la discapacidad, donde las características físicas de una persona son contempladas en su interacción con el entorno, requiere de estudios actitudinales de la población que faciliten la identificación de las barreras que limitan el ejercicio de los derechos en igualdad de oportunidades para las personas con discapacidad en contextos profesionales. El objetivo principal del estudio ha sido el diseño, construcción y validación de un instrumento de evaluación de las actitudes hacia la discapacidad en personal militar.Método:En el estudio han participado 204 militares de diferentes empleos y escalas, donde un 11,76 % fueron mujeres y un 88,24 % hombres. El desarrollo del trabajo estuvo dividido en dos fases. En la primera fase, se construye la escala y se somete a juicio de expertos analizando la concordancia entre los mismos con el fin de valorar la validez de contenido del cuestionario. En la segunda fase, se valoran las cualidades psicométricas de fiabilidad y validez (constructo y concurrente) de la escala.Resultados:Los resultados obtenidos reflejan propiedades psicométricas adecuadas y ajustadas del instrumento. En el análisis de la fiabilidad se observa que, tanto la escala en su conjunto (.87), como las dos subescalas que la conforman (.88 y .89), presentan una adecuada consistencia interna. En los análisis exploratorio y confirmatorio realizados, se obtiene un modelo con una solución de dos factores cuyos datos de bondad de ajuste (NFI = 0.94, GFI = 0.94, CFI = .97, RMSEA = .06 (IC 90 % = .048 - .070), RMR estandarizado = .091) garantizan una adecuada validez de constructo. Asimismo, se observa una adecuada validez concurrente (.76; p< .01).Conclusiones:Se concluye el uso justificado y óptimo del instrumento para la evaluación de las actitudes hacia la discapacidad en personal militar. (AU)

Background and objective: Currently, the conception of disability considers the physical characteristics of the person in their interaction with the environment. This understanding makes it necessary for the development of attitudinal studies of the population that facilitate the identification of barriers that limit the exercise of people with disabilities’ rights in equal opportunities in the professional field. The main objective of the study was the design, construction, and validation of an instrument to assess attitudes towards disability in the Armed Forces.Method:204 soldiers of different positions and scales participated in the study, where 11.76 % were women and 88.24 % were men. The study was divided into two phases. In the first phase, the scale was constructed and evaluated by a group of experts. The concordance between them was also analyzed in order to evaluate the validity of the content of the questionnaire. In a second phase, the psychometric qualities of reliability and validity (construct and concurrent) of the scale were evaluated.Results:The results obtained reflect appropriate psychometric properties adjusted to the instrument. The reliability analysis, shows that both, the scale as a whole (.87), and the two subscales that make it up(.88 and .89), present adequate internal consistency. In the exploratory and confirmatory analyses performed, it is obtained a model with a two-factor solution. Its goodness-of-fit data (NFI = 0.94, GFI = 0.94, CFI = .97, RMSEA = .06 (90 % CI = .048 - .070), standardized RMR = .091) guarantee adequate construct validity. Likewise, an appropriate concurrent validity is observed (.76; p<.01).Conclusions:In conclusion, the use of the instrument for the evaluation of attitudes towards disability in the Armed Forces is justified and optimal. (AU)

USE OF A FEMTOSECOND LASER IN CATARACT SURGERY.

AIMS: Cataracts continue to be the leading cause of blindness worldwide. Phacoemulsification is the gold standard in the treatment of cataracts. The aim of the study was to compare the postoperative results of the phacoemulsification technique in comparison with femtosecond laser-assisted cataract surgery (FLACS). MATERIAL AND METHODS: Our work retrospectively evaluates the results of patients after implantation of an artificial intraocular lens for cataract from May 2017 to March 2019. The study evaluated a total of 80 implanted lenses in 47 patients operated on by two surgeons. Of the 47 patients, 28 were women. The mean age in the group at the time of surgery was 63.7 years, ranging from 34-79 years. Patients could choose FLACS (n = 45) surgery or standard phacoemulsification procedure (n = 35). RESULTS: Upon a comparison of the group regarding uncorrected distal visual acuity (UCDVA) up to 12 months after surgery, the group FAKO CATARACTS recorded 0.85 ±0.18 vs. 0.93 ±0.12 in the FEMTO CATARACTS group (p = 0.021), comparably uncorrected near visual acuity (UCNVA) was 0.77 ±0.18 vs. 0.84 ±0.17 (p = 0.034) respectively. A difference in the use of phacoemulsification energy (OZIL) was measured in patients with phacoemulsification 3.5 ±3.1 and in the use of femtosecond laser 2.2 ±3.1, (p = 0.005). In all cases, an AT LISA 839 trifocal lens (Carl Zeiss Meditec, Germany) was implanted. CONCLUSION: The femtosecond platform assists the surgeon in cataract surgery with capsulorhexis and pre-fragmentation of the lens nucleus, which can be advantageous especially for complicated cataracts. We recorded significantly higher uncorrected distance and near visual acuity in the FLACS group, and also a significantly lower value of the phacoemulsification energy used.

Higher Prevalence of Babesia microti than Borrelia burgdorferi in Small Mammal Species in Central Pennsylvania, United States.

Babesia microti can lead to severe babesiosis in immunosuppressed populations, but due to high numbers of asymptomatic cases, clinical reporting is unable to define its geographic distribution. Although Lyme disease caused by Borrelia burgdorferi is endemic throughout Pennsylvania (PA), human babesiosis is under recognized, despite sharing the same vector and primary reservoir host. Ixodes ticks are known to carry B. microti throughout PA, but information about pathogen prevalence in small mammal reservoirs remains limited. Characterizing B. microti prevalence in these small mammals can elucidate mechanisms of pathogen spread and define geographic areas where humans are at risk of infection. We tested 692 small mammals across eight contiguous counties in central PA for molecular evidence of B. microti and B. burgdorferi. In total, six different small mammal species were collected. The overall prevalence of B. microti was 32% with similar rates observed across all counties. Surprisingly, this was higher than the prevalence of B. burgdorferi at 21%. In fact, high rates of B. microti were found in all six species, and both pathogens were identified in 11% of mammals tested. The prevalence of B. microti was highest in Myodes gapperi (southern red-backed vole) at 39% despite Peromyscus leucopus (white-footed mouse) being considered the primary reservoir host for B. microti. In conclusion, B. microti has a high prevalence across multiple small mammal species throughout central PA. This prevalence is greater than B. burgdorferi despite a much higher incidence of Lyme disease compared to babesiosis in PA. Although it remains unknown how the prevalence of B. microti in small mammal hosts corresponds to human infection rates, the high pathogen prevalence of B. microti suggests that it is an emerging pathogen in this area. Currently, babesiosis is not a reportable disease in PA, and additional studies are warranted to evaluate its clinical significance in this geographic region.

Evaluating the effectiveness of real-time feedback on the bedside hand hygiene behaviors of nursing students.

BACKGROUND: Traditional hand hygiene teaching methods lack long-term effectiveness. METHOD: A longitudinal, within-subject design explored the influence of real-time hand microbe feedback and a critical-thinking decision exercise on nursing student hand hygiene behaviors. In three community hospitals, the students' (n = 68) hand swabs were tested for normal flora, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus at three time points. Students completed the Partnering to Heal (PTH) online exercise on hospital-acquired infection prevention decisions. RESULTS: Normal flora colony counts decreased across the semester and MRSA-positive cultures increased in frequency and colony counts. MRSA-positive cultures were not associated with caring for patients in isolation precautions. Significantly higher colony counts were noted in the students who completed the PTH than those who did not complete the PTH. CONCLUSION: This study explores innovative pedagogy bringing the nonvisible microbial risk to the consciousness of nursing students in an attempt to change hand hygiene behaviors.

Pathogenic nontuberculous mycobacteria resist and inactivate cathelicidin: implication of a novel role for polar mycobacterial lipids.

Nontuberculous mycobacteria (NTM) are a large group of environmental organisms with worldwide distribution, but only a relatively few are known to be pathogenic. Chronic, debilitating lung disease is the most common manifestation of NTM infection, which is often refractory to treatment. The incidence and prevalence of NTM lung disease are increasing in the United States and in many parts of the world. Hence, a more complete understanding of NTM pathogenesis will provide the foundation to develop innovative approaches to treat this recalcitrant disease. Herein, we demonstrate that several species of NTM show broad resistance to the antimicrobial peptide, cathelicidin (LL-37). Resistance to LL-37 was not significantly different between M. avium that contain serovar-specific glycopeptidolipid (GPL, M. aviumssGPL) and M. avium that do not (M. aviumΔssGPL). Similarly, M. abscessus containing non-specific GPL (M. abscessusnsGPL(+)) or lacking nsGPL (M. abscessusnsGPL(-)) remained equally resistant to LL-37. These findings would support the notion that GPL are not the components responsible for NTM resistance to LL-37. Unexpectedly, the growth of M. abscessusnsGPL(-) increased with LL-37 or scrambled LL-37 peptide in a dose-dependent fashion. We also discovered that LL-37 exposed to NTM had reduced antimicrobial activity, and initial work indicates that this is likely due to inactivation of LL-37 by lipid component(s) of the NTM cell envelope. We conclude that pathogenic NTM resist and inactivate LL-37. The mechanism by which NTM circumvent the antimicrobial activity of LL-37 remains to be determined.

[Retinal tamponade with silicone oil - long term results]. / Tamponáda sietnice silikónovým olejom - dlhodobé výsledky.

AIM: The aim of this study is to evaluate the frequency and efficacy of silicone oil (SO) retinal tamponade in various retinal diseases. The incidence of silicone oil tamponade according to individual indications, incidence of complications and duration of tamponade were evaluated in the study. MATERIAL AND METHODS: A retrospective study included 510 eyes that were operated on pars plana vitrectomy (PPV) from January 2010 to December 2012. In our group we evaluated 241 men and 189 women, age 4-84 years, mean 62 years . Follow-up period was 12 to 48 months, an average of 27.5 months . We evaluated 253 eyes with diabetic retinopathy, 201 eyes with regmatogenous retinal detachment, 34 eyes with endophthalmitis and 22 eyes after the injury. RESULTS: In 253 diabetic retinopathy eyes (DR) silicone oil tamponade was indicated in 56 eyes (22.1 %). Silicone oil removal was done on 22 eyes (39.3 %), the average length of SO tamponade was 9.7 months. After SO removal BCVA (best corrected visual acuity) 0,1 and worse had 12 eyes (54,6 %), 0,2 - 0,4 had 5 eyes (22,7 %) and 0,5 or better had 5 eyes (22,7 %). Permanent SO tamponade was left in 34 diabetic retinopathy eyes (60.7 %). Secondary glaucoma (SG) was present in 40 eyes (71.5 %). In 201 retinal detachment (RD) eyes silicone oil tamponade was used in 76 eyes (37.8 %). Secondary glaucoma was present in 31 eyes (40.8 %). Silicone oil was successfully removed in 40 eyes (52.6 %), the average length of tamponade was 9.2 months. In this group BCVA 0,1 and worse had 22 eyes (55,0 %), 0,2 - 0,4 had 15 eyes (37,5 %) and 0,5 or better had 3 eyes (7,5 %). 36 eyes (47,4 %) RD eyes had permanent silicone oil tamponade. In a group of 34 eyes with endophthalmitis SO tamponade was used in 16 eyes (47 %). Secondary glaucoma was present in 3 eyes (18.8 %). Silicone oil removal we did in 11 eyes (68.8 %), the average length of SO tamponade was 5.5 months. After SO removal BCVA 0,1 and worse had 3 eyes (27,2 %), 0,2 - 0,4 had 4 eyes (36,4 %) and 0,5 or better had 4 eyes (36,4 %). 5 eyes (31.2 %) with endophthalmitis had permanent SO tamponade. Out of 22 eyes with eye injuries SO tamponade was used in 14 eyes (63.6 %). 5 eyes (35.7 %) had secondary glaucoma. In 9 eyes (64.3 %) silicone oil was removed, the average length of tamponade was 9.1 months. In this group BCVA 0,1 and worse had 6 eyes (66,7 %), 0,2-0,4 had 1 eye (11,1 %) and 0,5 or better had 2 eyes (22,2 %). Permanent silicone oil tamponade had 5 eyes (35,7 %). In group of 56 phakic eyes (100 %) with silicone oil tamponade we followed cataract progression. 26 eyes (40 %) had cataract surgery in 6 month follow up, 47 eyes (72.3 %) in 1 year follow up and 57 eyes (87.7 %) had cataract surgery in 3 years follow up. CONCLUSION: Silicone oil tamponade is the method of choice for long-term and stable retinal tamponade, which is important for good functional outcomes of the surgical intervention. The silicone oil tamponade of the retina is nowadays irreplaceable, despite of its potential risks and complications.

[Surgical treatment of the idiopatic macular hole - our experience]. / Chirurgická liecba idiopatickej diery makuly nase skúsenosti.

AIM: To evaluate the results of the idiopathic macular hole (IDM) surgical treatment. Surgery included pars plana vitrectomy (PPV) with the removal (peeling) of internal limiting membrane (ILM) and intraocular tamponade with a diluted expanding gas. MATERIAL AND METHODS: A retrospective study included 100 eyes of 96 patients (10 men and 86 women) with IDM, that were operated at II. Eye Clinic SZU in Banska Bystrica from August 2008 to August 2012. Patients age ranged from 48 to 86 years, average 69.3 years. Mean follow-up time was 39.2 months. All patients underwent PPV with the ILM peeling. Intraocular air tamponade was used in 1-case, 16 % SF6 84-times and 12 % C3F8 15 times. RESULTS: Anatomical success of the operation was evaluated with OCT examination. After primary operation there were 92 (92 %) closed macular holes in our study. In 6 patients (6 %), we decided to reoperate with gas tamponade (SF6 2-times, C3F8 4 times). After the reoperations final anatomical success in our study was 97 eyes (97 %). Functional results we examined with Snellen. Improved best corrected visual acuity (BCVA) was observed in 85 eyes (85 %), no changes in 11 eyes (11 %), and deterioration in 4 eyes (4 %). Improvement in vision was following: 1 line - 18 eyes, 2 lines - 20 eyes, 3 lines - 18 eyes, 4 lines - 11 eyes, 5 or more lines in 18 eyes. CONCLUSION: Pars plana vitrectomy with ILM peeling and gas tamponade is highly effective and safe treatment of idiopathic macular hole.Key words: idiopathic macular hole, pars plana vitrectomy, expanding gas.

[Gases in vitreoretinal surgery]. / Plyny vo vitreoretinálnej chirurgii.

AIM: To evaluate the importance and benefits of using gases in vitreoretinal surgery. MATERIAL AND METHODS: The gases represent a wide group of substances used in eye surgery for more than 100 years. The role of intraocular gases in vitreoretinal surgery is irreplaceable. Their use is still considered to be the "gold standard". An important step in eye surgery was the introduction of expanding gases--sulfur hexafluoride and perfluorocarbons into routine clinical practice. The most common indications for the use of intraocular gases are: retinal detachment, idiopathic macular hole, complications of vitreoretinal surgery and others. RESULTS AND CONCLUSIONS: The introduction of intraocular gases into routine clinical practice, along with other modern surgical techniques resulted in significant improvement of postoperative outcomes in a wide range of eye diseases. Understanding the principles of intraocular gases use brings the benefits to the patient and physician as well. Due to their physical and chemical properties they pose far the best and most appropriate variant of intraocular tamponade. Gases also bring some disadvantages, such as difficulties in detailed fundus examination, visual acuity testing, ultrasonographic examination, difficulties in application of intravitreal drugs or reduced possibility of retina laser treatment. The gases significantly change optical system properties of the eye. The use of gases in vitreoretinal surgery has significantly increased success rate of retinal detachment surgery, complicated posterior segment cases, trauma, surgery of the macula and other diseases.

[Lucentis in treatment of the wet-form of age-related macular degeneration--two years experience]. / Lucentis v liecbe vlhkej formy vekom podmienenej degenerácie makuly--dvojrocné skúsenosti.

In a study group of 114 patients (39 males, 75 females) with mean age of 72, 5 years (from 52 to 89 years) with mean follow-up of 8 month we retrospectively studied the effectivity and safety of intravitreal aplication of ranibizumab = Lucentis in the case of wet form of age-related macular degeneration (AMD). All patients met the inclusion criteria. The treatmet was realized on outpatient basis under strict application protocol. In the follow-up period the visual acuity improved in 66 patients (57%), stabilization was achieved in 17 patients (24.9%). In a group of 31 patients (27.2%) the central acuity deteriorated. There were no peroperative complications. In the postoperative period we observed in 22 patients temporary rise of intraocular pressure, in 21 patients suffusion, and in 3 patients there were subretinal haemorrhages found, in 1 case rupture of RPE and in 1 case anterior ischemic opticopathy was observed. Results observed in this study are in full compliance with PRONTO and PIER studies.

Induction of murine macrophage TNF-alpha synthesis by Mycobacterium avium is modulated through complement-dependent interaction via complement receptors 3 and 4 in relation to M. avium glycopeptidolipid.

We studied whether complement receptor (CR) mediated Mycobacterium avium interaction modulated macrophage TNF-alpha expression. Compared to control conditions, infections performed with C3-depletion yielded significantly higher TNF-alpha levels. Blockage of the CR4 iC3b site yielded increases in TNF-alpha for all morphotypic variants of a virulent serovar-8 strain (smooth transparent (SmT), smooth opaque (SmO), serovar-specific glycopeptidolipid (ssGPL) deficient knockout mutant) whereas CR3 blockage increased TNF-alpha only for SmT and ssGPL-deficient strains. Thus, complement-mediated binding of M. avium to CR3 and CR4 was shown to modulate TNF-alpha expression. The differential activation of morphotypic and isogenic variants of a single strain provides an excellent model system to delineate signaling pathways.

Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant.

BACKGROUND: Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL) of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. METHODS: To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA) gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt) rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. RESULTS: In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. CONCLUSION: We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH) resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis, biosynthesis, or drug resistance can be studied in a consistent manner.

Biosynthetic specificity of the rhamnosyltransferase gene of Mycobacterium avium serovar 2 as determined by allelic exchange mutagenesis.

In prior studies, through recombinant expression in Mycobacterium smegmatis, the rtfA gene of Mycobacterium avium was shown to encode a rhamnosyltransferase that catalyses the addition of rhamnose (Rha) to the 6-deoxytalose of serovar 2-specific glycopeptidolipid (GPL). Whether RtfA also catalyses the transfer of Rha to the alaninol of the lipopeptide core is unknown. An isogenic rtfA mutant of M. avium serovar 2 strain TMC724 was derived using a novel allelic exchange mutagenesis system utilizing a multicopy plasmid that contained the katG gene of Mycobacterium bovis and the gene encoding green fluorescent protein (gfp). Overexpression of KatG in M. avium resulted in increased susceptibility to isoniazid, thus providing counter-selection by enriching for clones that had lost plasmid DNA. Plasmid loss was confirmed by screening for gfp-negative clones to select putative allelic exchange mutants. Two exchange mutants were created, confirmed by Southern hybridization, and demonstrated loss of serovar 2-specific GPL by thin-layer chromatography (TLC). Gas chromatography of alditol acetate derivatives revealed the loss of Rha and the terminal 2,3-O-Me-fucose and preservation of 3-O-Me-Rha and 3,4-O-Me-Rha substituents at the terminal alaninol of the lipopeptide core. Complementation of rtfA in trans through an integrative plasmid restored serovar 2-specific GPL expression identical to wild-type TMC724. This result shows that rtfA encodes an enzyme responsible only for the transfer of Rha to the serovar 2-specific oligosaccharide and provides a system of allelic exchange for M. avium as a tool for future genetic studies involving this species.

Differential posttranslational processing of proenkephalin in rat bone marrow and spleen mononuclear cells: evidence for synenkephalin cleavage.

Proenkephalin (PENK) messenger RNA was reported to be present in bone marrow mononuclear cells (BMMC) and spleen mononuclear cells (SMC). Nevertheless, the pattern of PENK products in normal cells of the rat immune system, which is important for defining the physiological role of PENK gene expression, has not been well established. In this work we have characterized the processing of the opioid portion (met-enkephalin-containing peptides) and nonopioid portion (synenkephalin-derived peptides) of PENK in rat BMMC and SMC. Met-enkephalin-containing peptides were detected in mononuclear cells of both hematopoietic tissues. In BMMC, free immunoreactive (IR)-met-enkephalin corresponded only to the 15% of total met-enkephalin-IR, whereas in SMC it represented the 66.5%. Gel filtration chromatography showed that BMMC contained partially processed PENK-derived peptides of high and intermediate molecular weight, whereas SMC displayed fully processed products containing met-enkephalin and/or the carboxyterminal portion of synenkephalin. HPLC purification of low molecular weight products showed that free IR-met-enkephalin in SMC mainly corresponded to met-enkephalin and oxidized met-enkephalin. In addition we have characterized in SMC three peptides lower than 3.0 kilodalton containing the C-terminal sequence of synenkephalin. These peptides were purified by gel filtration, affinity chromatography, ion exchange chromatography, and HPLC. These results show that PENK was processed in mononuclear cells of the primary (bone marrow) and secondary (spleen) organs of the rat hematopoietic system, as occurs in neural and endocrine tissues. Nevertheless, the precursor was cleaved only in the latter tissue to low molecular weight peptides. Furthermore we demonstrated that synenkephalin (proenkephalin 1-70) in SMC was processed to low molecular weight peptides containing the C-terminus free. This last result suggests that a dibasic Lys-Lys and monobasic (Lys) sites were cleaved.

Association of endogenous synenkephalin containing peptides with intracellular membranes of bovine adrenal medulla.

The association of endogenous synenkephalin and met-enkephalin containing peptides with the membrane of bovine chromaffin granules and physicochemical characteristics of this association were studied. The associated materials were only released at a non physiological pH range and this effect was enhanced with growing salt concentrations (0.5, 1.0 and 2.0 M KSCN). A higher peptide dissociation occurred with membrane solubilizing agents (SDS greater than Triton X-100 greater than digitonin). In microsomes the materials dissociated with 2 M KSCN (pH 7.4) corresponded to peptides larger than 12.0 kDa, while in granules corresponded to molecules smaller than 8.5 kDa, displaying synenkephalin and met-enkephalin immunoreactivities. These data suggest that some sequence of the C-terminal portion of synenkephalin may be responsible for the association of proenkephalin derived peptides with microsome and granule membranes.

Regulation of human T lymphocyte mitogenesis by antibodies to CD3.

The inhibitory and mitogenic effects of anti-CD3 antibodies (anti-CD3) were examined in cultures of human peripheral blood T cells. Resting T cells required the presence of accessory cells (AC) or phorbol myristate acetate (PMA) to be stimulated by soluble anti-CD3 (OKT3 and 64.1). Anti-CD3 was unable to induce activation of AC-depleted T cells as determined by IL 2 receptor expression, IL 2 production, cell cycle analysis, or detectable DNA synthesis. Although T cell responses to PHA also required AC, far fewer were necessary to generate responses. Anti-CD3 inhibited PHA-stimulated T cell IL 2 production, IL 2 receptor expression and proliferation in partially AC-depleted cultures. Moreover, anti-CD3 was able to inhibit PHA responses when added to culture as late as 24 to 42 hr after the initiation of a 96-hr incubation. Increasing concentrations of PHA reduced the inhibitory effect of anti-CD3 on PHA-stimulated T cell proliferation, whereas IL 2 production remained suppressed. Anti-CD3 linked to Sepharose beads effectively inhibited PHA-stimulated T cell DNA synthesis, indicating that internalization of the CD3 molecule was not required for inhibition of PHA responses. Although inhibition of IL 2 production was a major effect of anti-CD3 in PHA-stimulated cultures, it was not the only apparent inhibitory effect because the addition of exogenous IL 2 could not prevent inhibition completely. Intact AC but not IL 1 also reduced anti-CD3-mediated inhibition of PHA responsiveness, whereas the addition of both IL 2 and AC largely prevented inhibition. Thus, anti-CD3 in the absence of adequate AC signals exerted a number of distinct inhibitory effects on mitogen-induced T cell activation. These results suggest that the CD3 molecular complex may play a role in regulating T cell responsiveness after engagement of the T cell receptor by a number of mechanisms, some of which involve inhibition of IL 2 production.