Probing the repulsive core of the nucleon-nucleon interaction via the (4)He(e,e'pN) triple-coincidence reaction.

We studied simultaneously the (4)He(e,e'p), (4)He(e,e'pp), and (4)He(e,e'pn) reactions at Q(2)=2(GeV/c)(2) and x(B)>1, for an (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum, in a region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive. The abundance of neutron-proton pairs is reduced as the nucleon momentum increases beyond ∼500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum. Our data are compared with calculations of two-nucleon momentum distributions in (4)He and discussed in the context of probing the elusive repulsive component of the NN force.

HLA-G-treated tolerogenic dendritic cells induce tolerogenic potential by increasing expression of B7-1 (CD80) molecules.

BACKGROUND: By consensus, HLA-G has a role in the induction of tolerance via interaction with dendritic cells and manipulation of co-stimulatory molecule expression. The purpose of this study was to demonstrate that HLA-G modified dendritic cells exhibit a decreased ability to stimulate T-cells in vitro due to increased expression of B7-1, which provides regulatory signalling to T-cells as a consequence of binding CD28 and CD152 ligands. METHODS: Bone-marrow cells were cultured from Brown Norway (BN) rat femurs and sorted with anti-rat dendritic cell Ab (OX62) microbeads. Isolated dendritic cells (DCs) were treated with HLA-G tetramer for 3 days. Initially, cells were plated with media, alloantigenic splenocytes, and T-cells and then observed in mixed lymphocyte reaction for thymidine uptake. Also, the cells were analyzed by flow cytometry using antibodies for MHC-II (IA), CD80, and CD86. RESULTS: This study displays that HLA-G-modified DCs decrease induction of an alloproliferative response. In addition, this study demonstrated that HLA-G tetramer treatment decreases CD86 and permits expression of CD80 without altering MHC-II expression. DISCUSSION: This study specifically investigated the role of B7-1 (CD80), showing that HLA-G treatment of immature DCs allows expression of B7-1 (CD80) without altering MHC-II expression and simultaneously decreases B7-2 (CD86) expression. Therefore, a low level of B7-2 (CD86) allows attenuation of T-cell response after activation, both of which are beneficial to immune tolerance. The selective expression of B7-1 (CD80) is important and may serve as a guide for future therapies aimed at transplant tolerance.

Relevance of zinc in human sperm flagella and its relation to motility.

OBJECTIVE: To measure the zinc content of human sperm flagella and to analyze its relation to sperm motility. DESIGN: Prospective study. SETTING: Center of Dermatology and Andrology. PATIENT(S): Semen samples collected from 90 andrology patients and healthy donors after 3-5 days of sexual abstinence. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Sperm morphology after Shorr staining, sperm motility, and patient age were recorded. In addition, zinc concentrations in the seminal plasma, sperm heads, and flagella were determined with the use of atomic absorption spectrometry. RESULT(S): The mean zinc concentration was 144.3 mg/L in the seminal plasma and 146.9 mg/L in the whole ejaculate and was significantly correlated with parameters of motility. The sperm heads contained only 6.7% of the zinc that was present in the whole spermatozoon. The zinc concentration in the flagella was negatively correlated with sperm motility and velocity. In addition, it was positively correlated with the percentage of abnormally blue-stained flagella and the age of the patients. CONCLUSION(S): Our results clearly demonstrate the importance of zinc elimination during epididymal sperm maturation for functional competence of the outer dense fibers and, therefore, generation of motility.

Contributions to the taxonomy and biology of Clostridium difficile.

Clostridium difficile was incriminated by Hughes and Jarvis (1987) as a cause of intestinal infections in USA in the 1980-1984 period in 45 p. 100 of cases, whereas Salmonellae only in 12 p. 100. Four strains of this organism are studied in this paper in comparison with ten strains of C. bifermentans and six of C. sordellii, because the three species share a common antigen and have other common characteristics, as well. However, spores of C. difficile swell the bacteria and those of other bacteria (C. bifermentans and C. sordellii) do not; C. difficile does not produce indole, whereas the other species produce it. We confirmed the selective capacity of the medium of George et al. (1979) using the "alcohol shock" and as selective agents cycloserine D and cefoxitin. C. difficile proved to be most susceptible to metronidazole and rifampin. Whereas the former antibiotic was considered as a cause of post-antibiotic intestinal infections by different authors, the second was not, to our knowledge. The strain 10463 has a considerable toxicity (1000 DLM/ml for the white mouse, and pathogenicity--2000--5000 DCL for the white mouse, as compared to 25 DCL of the other three strains). Using this toxin an antitoxic serum was obtained in horse, with a capacity of neutralizing the action of the toxin up to a dilution of 1 p. 1000.

Detection of Bacteroides fragilis group by immunofluorescence.

The following strains: B. fragilis subspecies thetaiotaomicron (A); B. fragilis subspecies fragilis strain E-1, E-2, M, St., Se., Ni., 8, 16; B. fragilis subspecies distasonis 145 (D) were serologically studied by immunofluorescence as compared to agglutination. Anti-B. fragilis sera titration by immunofluorescence (IF) reaction, as compared to agglutination reaction in tube, was more sensitive (2-16 times higher titers), specific and reproducible. Among the organisms from B. fragilis group, species, subspecies and even train specificity was noticed. Also, the possibility for rapid identification of anaerobic organisms, belonging to B. fragilis group, in pathologic products obtained from experimentally infected animals (mice and rats), by IF reaction, in comparison with classic methods (anaerobic cultures and biochemical determinations) was studied. Of 87 studied animals, 61 proved positive by cultures and 59 by IF; 56 animals were shown positive and 23 animals proved negative by both methods (intermethods concordance in 79 cases). Statistical analysis of IF results provided the following: method sensitivity (detection capacity of real-positive cases)-91.80%; method specificity (detection capacity of real-negative cases)-88.46%; false-positive cases-11.53%; false-negative cases-8.19%. Immunofluorescence proved specific, sensitive, practical and rapid method detection of non-sporulated anaerobic organisms species and subspecies belonging to Bacteroides fragilis group.

[A case of Caffey-Silverman syndrome in a 3.5 month old infant]. / Przypadek zespolu Caffeya-Silvermana u 3,5-miesiecznego niemowlecia.

The authors presented a case of Caffey-Silverman syndrome in 3.5 months old infant with the lesions only in mandible.

[The timely diagnosis of postoperative clostridial infection]. / Diagnosticul în timp util al infectiei clostridiene postoperatorii.

Authors report a case of clostridial myonecrosis postcholecystectomy. The causes of the occurrence of this severe, frequently lethal complication are reviewed, as well as the difficulties of an early diagnosis, the only factor able to save the patient. The curative treatment of the detected infection requires the initiation of a series of local and general measures and a permanent cooperation between the surgeon, the specialist in resuscitation and the infectionist.

[Effect of rocuronium on the diaphragm, musculus adductor pollicis and orbicularis oculi in two groups of different age]. / Neuromuskuläre Wirkzeiten von Rocuronium am Diaphragma, Musculus adductor pollicis und orbicularis oculi in zwei Altersgruppen.

OBJECTIVE: Onset time and recovery from non depolarising neuromuscular blockade depends on the tested muscle and is influenced by the age of the patient. This study compares the neuromuscular blocking effect of rocuronium on the diaphragm, adductor pollicis and orbicularis oculi muscle in young and elderly patients. METHODS: After institutional ethics committee approval and written informed consent, 20 adult patients (ASA I - II), age 18 - 59 and > 65, have been included. Neuromuscular response was measured by accelerography for the adductor pollicis and orbicularis oculi muscle. Monitoring of the diaphragm consisted of measurement of the airway pressure against an occluded tracheal tube during magnetic phrenic nerve stimulation. Onset time and recovery were measured after injection of 0.6 mg/kg Rocuronium. RESULTS: The adductor pollicis had the fastest onset time ( young 2.3 min, old 2.2 min), followed by diaphragm ( young 3.6 min, old 3.4 min) and orbicularis oculi muscle ( young 3.7 min, old 4.8 min). There was a complete blockade of the diaphragm in 50 % of all patients (Adductor pollicis 100 %, orbicularis oculi 40 %). Neuromuscular recovery, recovery index and TOF 0.8 differed significantly between young and elderly patients. Onset of recovery was earlier at the diaphragm ( young 15.9 min, old 22.0 min) compared to the peripheral muscles (adductor pollicis young 25.6 min, old 37.9 min, orbicularis oculi young 23.8 min, old 27.5 min). CONCLUSION: 2 fould ED95 of rocuronium often results in an incomplete neuromuscular blockade of the diaphragm. Therefore monitoring of the peripheral muscles in patients given a single dose of rocuronium often overestimates the degree of diaphragmatic relaxation, but is a save predictor of recovery. Especially in elderly patients were prolonged neuromuscular blockade should be expected, a neuromuscular monitoring is recommended.

[Simple method for production of conditions of general anaerobiosis]. / Metoda simpla pentru realizarea conditiilor de anaerobioza generala

The description is given of a modified method starting from the alkaline pyrogalol technique, described by Béerens and Tahon-Castel, for obtaining anaerobiosis in Petri dishes. The modification consists in: sealing the dishes with paraffin, adding of talcum in the reducing mixture instead of silica, and use of the ready prepared mixture ovar a period of at most 6 months. The method was tested against the reference method using suspensions of C. Oedematiens (species demanding strictly anaerobiosis conditions), C. histolyticum (somewhat less exigent) and C. perfringens spores (mean esigence), seeding on the surface of dishes with Willis-Hobbs medium. The comparative experiment, counting 30,941 colonies on 408 Petri dishes proved the value of the method proposed. The procedure was just as efficient in surface cultures of nonsporulate anaerobic germs.

The clinical significance, taxonomy and special methodological problems of the pathogenic clostridia.

The clinical significance of clostridia is much greater than is generally recognized. The organisms are a major cause of septic abortion, Clostridium perfringens being the most important single organism. This species is also the principle agent in food-poisoning. Clostridium botulinum is considered to be one of the main causes of the sudden death syndrome in infants. As clostridia are universally distributed in nature and the human body, the isolation of an organism of this group from the human body is significant only if it can be linked with pathological changes. In the case of histotoxic disease, a direct gramstained smear from the lesion is of paramount importance, since the pathogens are always present in large numbers. Generally, a few simple procedures and tests ensure the rapid isolation and identification of the main pathogenic clostridia. C. perfringens, by far the most important species, may be identified by its ability to produce lecithinase on egg yolk-glucose agar and stormy clot in litmus milk. However, strain identification of this microorganism is much more complicated.

[Reality in the sciences of humans]. / Zur Wirklichkeit in den Wissenschaften vom Menschen.

The claim of science, which concerns directly human living, to be "objective" and "universal" culminates in the belief, scientific methods could represent reality. Such a science puts men in a couple of scientific laws and suppresses the moment of active doing (accepting or refusing) as a sufficient preassumption of reality. In an alternative way we are looking for a science where reality means invitation to perform own doing.

[Sensitivity to combined metronidazole and penicillin in 227 strains of non-sporulated anaerobic bacteria]. / Sensibilitatea la combinatia metronidazol-penicilina a 227 de tulpini de germeni anaerobi nesporulati.

Combined metronidazol-penicillin, used in large amounts corresponding to the selective concentrations in vitro of 25 + 25 IU, may be assumed to be effective in all clinical infections in which one or several anaerobes are implicated. The experiments carried out demonstrate that this is valid for all categories of Grampositive or Gramnegative non-sporulate anaerobes. The antibiotic concentrations used are well tolerated by the human organism.

Decreased proliferation of human melanoma cell lines caused by antisense RNA against translation factor eIF-4A1.

Control of translation initiation was recognised as a critical checkpoint for cell proliferation and tumorigenesis. In human melanoma cells, we have previously reported consistent overexpression of translation initiation factor eIF-4A1. Here, we investigated by transfection of antisense constructs its significance for the control of melanoma cell growth. The tetracycline-inducible expression system was established in melanoma cells, and three fragments of the 5'-, central-, and 3'-portion of the eIF-4A1 cDNA were subcloned in antisense and in sense orientation after a tetracycline inducible promoter. Significant proliferation decrease was obtained after transient transfection and induction of antisense RNA directed against the 5'- and the central portion (up to 10%), whereas, no effects were seen after induction of the 3'-fragment and the sense controls. Cell clones stably transfected with the central antisense fragment revealed after doxycycline induction reduced expression of endogeneous eIF-4A1 mRNA correlated with decreased proliferation rates (up to 6%). These data demonstrate the applicability of antisense strategies against translation factors in melanoma cells. Translation initiation factor eIF-4A1 contributes to the control of melanoma cell proliferation and may be taken into consideration when scheduling new therapeutic approaches targeting the translational control.