Association between anatomopathologic graft disorders during reperfusion and vena cava sIL-2r in orthotopic liver transplantation

Graft ischemia-reperfusion injury during orthotopic liver transplantation (OLT) is associated with anatomic and pathologic disorders in the graft, which may cause initial dysfunction. The object of this paper was to evaluate sIL-2r as an indicator of liver damage during graft reperfusion.

MATERIAL AND METHODS

Blood samples were drawn from 20 consecutive patients who required OLT secondary to chronic end-stage insufficiency various sites (portal vein, vena cava, pulmonary artery) and during different surgical phases. Following centrifugation and storage at -70 degrees C, sIL-2r was quantitated by chemiluminescence (Immulite, EURO/DPC). In addition biopsies were graded from 0 to III according to the anatomic and pathologic findings. Base excess and ammonia were measured to evaluate the function of the new liver.

STATISTICAL ANALYSES

Parameter associations were explored using Spearman's Rho and Kendall's Tau-b methods.

RESULTS

There was a correlation between the degree of graft preservation and sIL-2R both during vena cava reperfusion (r=.0591, P=.05) and for the initial 2 hours after reperfusion (r=0.61, P=.062).

CONCLUSION

sIL-2r levels drawn from the vena cava after graft reperfusion are associated with its degree of injury.

Classifying psychotic disorders: issues regarding categorial vs. dimensional approaches and time frame to assess symptoms

The study's aims were to empirically derive classes of disorders and dimensional syndromes within psychotic disorders on the basis of the three time frames of symptom assessment and to comparatively examine their external validity. The level of concordance among classes and among dimensions across the time frames was generally low. The external correlates of psychopathological syndromes differed as a function of both type of assessment and the dimensional or categorical approach used. The dimensional approach was more effective than the categorical approach in predicting a set of clinical variables, irrespective of the time frame used to assess the symptoms. It is concluded that classification of psychotic disorders is highly dependent upon the time frame considered to assess symptoms and that dimensional classifications do have higher predictive power than categorical ones.

Allozyme diversity in endemic flowering plant species of the Juan Fernandez Archipelago, Chile: ecological and historical factors with implications for conservation

The level and apportionment of allozyme diversity were determined for 29 endemic (and 1 native) species from the Juan Fernández Islands, Chile. Mean diversities at the species level (H(es) = 0.065) are low but comparable to those measured for other insular endemics in the Pacific. A high mean proportion (0.338) of species-level diversity resides among populations. Diversity statistics were compared for species in different ecological-life history trait categories and abundance classes. Species occurring in large populations and those present in scattered small populations have higher diversities than species occurring in one or two populations. Although not significant with the conservative statistical test employed, lower diversity was found in highly selfing species as compared to animal- or wind-pollinated species. The apportionment of genetic diversity within and among populations (G(ST) values) is not significantly different for any of the species categories. Of particular interest is the lack of difference between animal- and wind-pollinated species because previous analyses of large data sets showed higher differentiation between populations of animal- than wind-pollinated species. Historical factors, both ecological and phylogenetic in nature, can influence the level and apportionment of diversity within insular endemics, and thus ecological correlates of diversity seen in many continental species may not apply to endemics. The results have several conservation implications. The preservation of large populations or several small populations is important for conserving diversity within species because when species are reduced to one or two populations, allozyme diversity is sharply reduced. High mean G(ST) values for the species examined illustrate the need for conserving as many populations as possible, either in the wild or in the garden, to preserve maximal diversity within species. Effective conservation strategies require empirical knowledge of each species.

Teleophthalmology link between a primary health care centre and a reference hospital

We have evaluated a teleophthalmology service linking a primary health care centre and an eye clinic at a reference hospital. General practitioners at the primary care centre serving a population of 15,000 and ophthalmologists at the reference hospital participated in this study. Eye fundus digital images were taken from 278 eye fundi of 139 consecutive patients with clinical conditions that could potentially produce fundus alterations. Fundus images were obtained with a non-mydriatic fundus camera (Canon CR6-45M) and were electronically sent reference hospital where ophthalmologist inspected the images and returned the diagnosis. In 18 patients (13%) the images did not have good enough quality to exclude eye fundus lesions. In 24 patients (17%) clear eye fundus alterations were found in at least one eye. In 14 patients (10%) there were image features suggesting retinal alterations that could not be confirmed by image inspection. Media opacity (13 eyes, 5%, seven patients, 5%) was the most common cause of poor image quality. The most difficult assessment was the evaluation of optic nerve head cupping. Retinal oedema was not observable in the digital images. In our experience teleopthalmology services seem to be an effective alternative for eye fundus diagnosis and patient follow-up.

Selective chemical inactivation of AAA proteins reveals distinct functions of proteasomal ATPases

BACKGROUND

The 26S proteasome contains six highly related ATPases of the AAA family. We have developed a strategy that allows selective inhibition of individual proteasomal ATPases in the intact proteasome. Mutation of a threonine in the active site of Sug1/Rpt6 or Sug2/Rpt4 to a cysteine sensitizes these proteins to inactivation through alkylation by the sulfhydryl modifying agent NEM. Using this technique the individual contributions of Sug1 and Sug2 to proteasome function can be assessed.

RESULTS

We show that both Sug1 and Sug2 can be selectively alkylated by NEM in the context of the intact 26S complex and as predicted by structural modeling, this inactivates the ATPase function. Using this technique we demonstrate that both Sug 1 and 2 are required for full peptidase activity of the proteasome and that their functions are not redundant. Kinetic analysis suggests that Sug2 may have an important role in maintaining the interaction between the 19S regulatory complex and the 20S proteasome. In contrast, inhibition of Sug1 apparently decreases peptidase activity of the 26S proteasome by another mechanism.

CONCLUSIONS

These results describe a useful technique for the selective inactivation of AAA proteins. In addition, they also demonstrate that the functions of two related proteasomal AAA proteins are not redundant, suggesting differential roles of proteasomal AAA proteins in protein degradation.

Large scale transgenic and cluster deletion analysis of the HoxD complex separate an ancestral regulatory module from evolutionary innovations

The ancestral role of the Hox gene family is specifying morphogenetic differences along the main body axis. In vertebrates, HoxD genes were also co-opted along with the emergence of novel structures such as limbs and genitalia. We propose that these functional recruitments relied on the appearance, or implementation, of regulatory sequences outside of the complex. Whereas transgenic human and murine HOXD clusters could function during axial patterning, in mice they were not expressed outside the trunk. Accordingly, deletion of the entire cluster abolished axial expression, whereas recently acquired regulatory controls were preserved.

Comparative analysis of outcome and clinical features in children with pleural empyema caused by penicillin-nonsusceptible and penicillin-susceptible Streptococcus pneumoniae

OBJECTIVE

To describe the clinical characteristics of pleural empyema in children caused by Streptococcus pneumoniae nonsusceptible to penicillin and compare their clinical outcome with pleural empyemas caused by penicillin-susceptible organisms.

METHODS

Records of 109 children with complicated pleural effusions between January 1996 and December 1998 were retrospectively reviewed.

RESULTS

Pathogens were recovered in 45 of these cases. Streptococcus pneumoniae represented 71% of the isolates, with 20 (62%) and 12 (38%) of the strains proving susceptible and nonsusceptible to penicillin, respectively. The average age for children with penicillin-nonsusceptible infections was 18.3 months compared with an average age of 40.9 months for those with penicillin-susceptible infections (P = 0.03). Previous antibiotic treatment was more frequent in children with penicillin-nonsusceptible organisms (P = 0.05). No significant differences were found between the two groups for gender, underlying diseases, duration of fever and tachypnea, need of surgical treatment, bacteremia incidence, mean duration of therapy, or length of hospital stay.

CONCLUSIONS

Pleural empyemas caused by penicillin-nonsusceptible S. pneumoniae appear to be associated with younger age and previous antibiotic treatment. By contrast, the outcome was not influenced by the penicillin susceptibility of the pneumococcus strains.

The Gal4 activation domain binds Sug2 protein, a proteasome component, in vivo and in vitro

An in vivo protein interaction assay was used to search a yeast cDNA library for proteins that bind to the acidic activation domain (AD) of the yeast Gal4 protein. Sug2 protein, a component of the 19 S regulatory particle of the 26 S proteasome, was one of seven proteins identified in this screen. In vitro binding assays confirm a direct interaction between these proteins. SUG2 and SUG1, another 19 S component, were originally discovered as a mutation able to suppress the phenotype of a Gal4 truncation mutant (Gal4(D)p) lacking much of its AD. Sug1p has previously been shown to bind the Gal4 AD in vitro. Taken together, these genetic and biochemical data suggest a biologically significant interaction between the Gal4 protein and the 19 S regulatory particle of the proteasome. Indeed, it is demonstrated here that the Gal4 AD interacts specifically with immunopurified 19 S complex. The proteasome regulatory particle has been shown recently to play a direct role in RNA polymerase II transcription and the activator-19 S interaction could be important in recruiting this large complex to transcriptionally active GAL genes.

Receptive field organization of disparity-sensitive cells in Macaque medial superior temporal cortex

Binocular disparities are crucial for building an accurate three-dimensional representation of the peripersonal environment in a viewer-centred frame of reference. Previous studies have shown that visual cells of the medial superior temporal cortex (MST) have large receptive fields and that they are sensitive to disparities present in large surfaces. By using a reverse cross-correlation technique in this study we tested 175 disparity-sensitive units recorded from MST in the awake Macaca mulatta monkey to determine if these large receptive fields are homogeneous in terms of disparity sensitivity. We found that the receptive fields of 50 cells (50 out of 175, 29%) showed subregions with specific disparity sensitivity. These subregions presented eccentricities from 0.8 to 22.3 degrees and their sizes varied from 1.6 to 15.3 degrees 2. This particular receptive field organization represents a suitable mechanism for encoding the location of small objects within our peripersonal space.

The 19S regulatory particle of the proteasome is required for efficient transcription elongation by RNA polymerase II

It is generally thought that the primary or even sole activity of the 19S regulatory particle of the 26S proteasome is to facilitate the degradation of polyubiquitinated proteins by the 20S-core subunit. However, we present evidence that the 19S complex is required for efficient elongation of RNA polymerase II (RNAP II) in vitro and in vivo. First, yeast strains carrying alleles of SUG1 and SUG2, encoding 19S components, exhibit phenotypes indicative of elongation defects. Second, in vitro transcription is inhibited by antibodies raised against Sug1, or by heat-inactivating temperature-sensitive Sug1 mutants with restoration of elongation by addition of immunopurified 19S complex. Finally, Cdc68, a known elongation factor, coimmunoprecipitates with the 19S complex, indicating a physical interaction. Inhibition of the 20S proteolytic core of the proteasome has no effect on elongation. This work defines a nonproteolytic role for the 19S complex in RNAP II transcription.

Black widow bites in children

While seldom lethal, the bite of the black widow spider causes serious systemic symptoms that appear suddenly and progress rapidly. Children are more vulnerable to these complications; therefore, early hospitalization and aggressive therapy must be considered. General information about the widow spider genus is presented, and an illustrative case and treatment options are discussed.

Binocular interaction and sensitivity to horizontal disparity in visual cortex in the awake monkey

We evaluated the binocular interaction and horizontal disparity sensitivity in neurons recorded from macaque visual cortex. Neurons from V1 of three awake Macaca mulatta monkeys were isolated by means of extracellular recording and tested for disparity sensitivity with dynamic random dot stereograms. Neurons sensitive to horizontal disparities were stimulated both monocularly and binocularly with flashing bars and their responses quantified. ANOVA and regression tests were used for data analysis. Sixty-six cells out of 185 (66/185, 36%) showed sensitivity to horizontal disparity. Disparity sensitive cells were grouped into near (25/66, 38%), tuned inhibitory (16/66, 24%), far (13/66, 20%) and tuned excitatory (12/66, 18%). Receptive fields of tuned cells were located more centrally in the visual field than those of near and far cells. The binocular interaction in tuned inhibitory cells increased linearly along with ocular unbalance. Most of tuned excitatory cells (10/12, 83%) showed facilitatory binocular interaction, characterized by a stronger response to binocular stimulation than to the stimulation of the dominant eye. On the contrary, most of tuned inhibitory cells (14/16, 88%) showed suppressory binocular interaction, characterized by a weaker response to binocular stimulation than to the stimulation of the dominant eye. Near and far cells showed both types of interaction in similar percentages. The binocular response showed a linear relationship with the sum of both monocular responses in tuned excitatory, tuned inhibitory and near cells, but not in far cells. Sensitivity to horizontal disparity may be a result of facilitatory and suppressive interactions between left and right inputs.

Response latencies to visual stimulation and disparity sensitivity in single cells of the awake Macaca mulatta visual cortex

The onset response latencies to dynamic random dot figures (solid figures) and dynamic random dot stereograms were measured in single units recorded from areas V1 and V2 of two awake Macaca mulatta monkeys. We studied 56 cells, 39 from V1 and 17 from V2. In 14 disparity sensitive and 13 disparity unsensitive cells from V1 the median latencies to solid figures were 59.8 and 73.6 ms, respectively, which were statistically different. In 26 disparity sensitive cells from V1 and 17 from V2 the median latencies to stereofigures were 85.6 and 97.9 ms, respectively, which were statistically different. These results indicate that V1 disparity sensitive cells may have shorter integration time than disparity unsensitive cells and that there is a transferring delay for disparity information between areas V1 and V2.

Diode laser photocoagulation of choroidal neovascularization associated with retinal pigment epithelial detachment

AIMS/BACKGROUND

Association of choroidal neovascularization with pigment epithelial detachment is not an uncommon feature. Since this condition usually has a poor visual outcome, new treatments should be developed.

METHODS

We studied the anatomical and visual results of 11 eyes with this association as a manifestation of an Exudative Age Related Macular Degeneration which were treated with diode laser photocoagulation guided by indocyanine green angiography. The average follow up time was 25.5 months (from 12 to 48 months).

RESULTS

Complete closure with complete resolution of the exudates and flattening of the detachment was observed in five eyes (45%). Visual acuity in the final examination improved or remained stable in 6 cases (55%).

CONCLUSION

These results indicate that diode laser photocoagulation guided by indocyanine green angiography is at least as effective as conventional lasers with shorter wavelengths for treatment of vascularized pigment epithelial detachments in Age Related Macular Degeneration.

Catecholamine levels in practitioners of the transcendental meditation technique

With the aim of evaluating the sympathetic-adrenal medulla system in subjects practicing transcendental meditation (TM), their plasma catecholamine levels were determined at two different times of day. The study group consisted of 19 subjects who regularly practice either TM or Sidhi-TM technique, with a control group made up of 16 healthy subjects who had not previously used any relaxation technique. Catecholamine plasma levels were determined by high performance liquid chromatography, at 0900 and 2000 h. Morning and evening norepinephrine (NE) levels and morning epinephrine (E) levels were significantly lower in the TM group than in the control subjects (morning NE levels, pg/ml, mean+/-S.E.: TM group 136.6+/-13.0, control 236.8+/-21.0, P=.0001; evening NE levels: TM group 119.7+/-10.8, control 175.6+/-17.4, P=.009; morning E levels, pg/ml: TM group 140.2+/-10.6, control 196.7+/-23.8, P=.019). No differences were recorded for evening E levels and dopamine (DA) levels. No significant differences were found for catecholamine levels measured at different times of day in the TM group, demonstrating a lack of daily hormonal rhythm. Anxiety levels were similar in both groups. Based on the results obtained, it can be considered that the regular practice of TM has a significant effect on the sympathetic-adrenal medulla system. A low hormonal response to daily stress caused by sympathetic tone regulation through regular TM could explain our results, as well as the physiological and other effects related to the field of health described in those who practice meditation.

Monocular Visual Loss in a Patient Undergoing Cisplatin Chemotherapy

Chemotherapeutic agents used against tumours have a variety of toxic effects. We describe a case of acute blindness in the left eye of a patient after treatment with cisplatin for lung cancer. Both the clinical findings and the absence of either ocular or retrobulbar metastasis suggested that the condition was related to chemotoxicity.

Differences that matter: major cytotoxic T cell-stimulating minor histocompatibility antigens

Despite thousands of genetic polymorphisms among MHC matched mouse strains, a few unknown histocompatibility antigens are targeted by the cytotoxic T cells specific for tissue grafts. We isolated the cDNA of a novel BALB.B antigen gene that defines the polymorphic H28 locus on chromosome 3 and yields the naturally processed ILENFPRL (IFL8) peptide for presentation by Kb MHC to C57BI/6 CTL. The CTL specific for the IFL8/Kb and our previously identified H60/Kb complexes represent a major fraction of the B6 anti-BALB.B immune response. The immunodominance of these antigens can be explained by their differential transcription in the donor versus the host strains and their expression in professional donor antigen-presenting cells.