Cloning of a human cDNA encoding a novel enzyme involved in the elongation of long-chain polyunsaturated fatty acids

The Saccharomyces cerevisiae protein ELO2p is involved in the elongation of saturated and monounsaturated fatty acids. Among several sequences with limited identity with the S. cerevisiae ELO2 gene, a consensus cDNA sequence was identified from the LifeSeq(R) database of Incyte Pharmaceuticals, Inc. Human liver cDNA was amplified by PCR using oligonucleotides complementary to the 5' and 3' ends of the putative human cDNA sequence. The resulting full-length sequence, termed HELO1, consisted of 897 bp, which encoded 299 amino acids. However, in contrast with the ELO2 gene, expression of this open reading frame in S. cerevisiae demonstrated that the encoded protein was involved in the elongation of long-chain polyunsaturated fatty acids, as determined by the conversion of gamma-linolenic acid (C(18:3, n-6)) into dihomo-gamma-linolenic acid (C(20:3, n-6)), arachidonic acid (C(20:4, n-6)) into adrenic acid (C(22:4, n-6)), stearidonic acid (C(18:4, n-3)) into eicosatetraenoic acid (C(20:4, n-3)), eicosapentaenoic acid (C(20:5, n-3)) into omega3-docosapentaenoic acid (C(22:5, n-3)) and alpha-linolenic acid (C(18:3, n-3)) into omega3-eicosatrienoic acid (C(20:3, n-3)). The predicted amino acid sequence of the open reading frame had only 29% identity with the yeast ELO2 sequence, contained a single histidine-rich domain and had six transmembrane-spanning regions, as suggested by hydropathy analysis. The tissue expression profile revealed that the HELO1 gene is highly expressed in the adrenal gland and testis. Furthermore, the HELO1 gene is located on chromosome 6, best known for encoding the major histocompatibility complex, which is essential to the human immune response.

Identification and characterization of an enzyme involved in the elongation of n-6 and n-3 polyunsaturated fatty acids

The enzymes that are involved in the elongation of fatty acids differ in terms of the substrates on which they act. To date, the enzymes specifically involved in the biosynthesis of polyunsaturated fatty acids have not yet been identified. In an attempt to identify a gene(s) encoding an enzyme(s) specific for the elongation of gamma-linolenic acid (GLA) (18:3n-6), a cDNA expression library was made from the fungus Mortierella alpina. The cDNA library constructed in a yeast expression vector was screened by measuring the expressed elongase activity [conversion of GLA to dihomo-GLA (20:3n-6)] from an individual yeast clone. In this report, we demonstrate the isolation of a cDNA (GLELO) whose encoded protein (GLELOp) was involved in the conversion of GLA to dihomo-GLA in an efficient manner (60% conversion). This cDNA contains a 957-nucleotide ORF that encodes a protein of 318 amino acids. Substrate specificity analysis revealed that this fungal enzyme acted also on stearidonic acid (18:4n-3). This report identifies and characterizes an elongase subunit that acts specifically on the two Delta6-desaturation products, 18:3n-6 and 18:4n-3. When this GLELO cDNA was coexpressed with M. alpina Delta5-desaturase cDNA in yeast, it resulted in the conversion of GLA to arachidonic acid (20:4n-6) as well as the conversion of stearidonic acid to eicosopentaenoic acid (20:5n-3). Thus, this GLELO gene may play an critical role in the bio-production of both n-6 and n-3 polyunsaturated fatty acids.

An unusual case of double outlet right ventricle

A 17-year-old unmarried girl was admitted with the complaints of breathlessness on exertion, swelling of upper and lower limbs and intermittent fever for last 21 days. Past history revealed bluish discolouration of nails and tongue since birth along with recurrent dyspnoea. After thorough general and cardiovascular examination, a provisional diagnosis of tetralogy of Fallot was made. Chest x-ray revealed cardiomegaly and absent main pulmonary artery segment. ECG revealed gross right axis deviation and right ventricular hypertrophy. Echocardiogram showed features of double outlet right ventricle.

Case-control and qualitative study of attrition in a community epilepsy programme in rural India

Dropout from epilepsy programmes is a serious problem in developing countries and has not been systematically studied before. We set up a community-based programme for children with epilepsy in rural India. The aim of this study was to assess reasons for dropout. We assessed medical and sociodemographic variables for their effect on dropout at 12 months using an unmatched case-control design on 32 cases and 62 controls. We also interviewed the parents of 32 children who dropped out of treatment, using a topic schedule. Two-thirds of the dropouts occurred within the first 6 months of treatment. Severely impaired children were more likely to drop out (odds ratio 4.60, 95% CI: 1.0-21.0) and families who had tried AEDs before were less likely to do so (odds ratio 0.12, 95% CI: 0.015-0.88). Denial of diagnosis, access problems and symptom resolution were the other main reasons underlying attrition. Active ascertainment methods should be reconsidered in community programmes. Very poor families without a male head or with long journey times are at high risk of dropout. People with severe impairments need appropriate integrated rehabilitation.

Kinetics of SO4(-2) reduction under different growth media by sulfate reducing bacteria

Sulfate Reducing Bacteria (SRB) were used to reduce the SO4(-2) concentration in waste water. The growth pattern of SRB was found by varying the concentration of nutrients and the biomass. The specific reaction constant was evaluated in each case.

Protein A-activated rat splenic lymphocyte proliferation involves tyrosine kinase-phospholipase C-protein kinase C pathway

Protein A (PA) of Staphylococcus aureus was long been known for its affinity towards the Fc domain of immunoglobulin G. It is now well established that PA is a potent biological response modifier showing simultaneously antitumor, antitoxic, and anticarcinogenic properties. This bacterial protein was also observed to stimulate production of cytokines. But the molecular mechanism(s) of immunocyte activation by PA still remained essentially unknown. In this report, we demonstrate a hitherto undescribed role of PA as a signal inducer in rat splenic lymphocytes. Our studies describe that PA induces transition of G0/G1 to S and G2/M phases of cell cycle, thus ultimately stimulating splenic lymphocyte proliferation. It has also been revealed that PA binds to rat splenic lymphocytes in a dose dependent manner and stimulates proliferation via tyrosine kinase-phospholipase C (PLC)-Ca2+-dependent protein kinase C (PKC) pathway. These observations will be of valid help in correlating the immunostimulatory activities of PA with the molecular mechanism(s) of its action.

[(186/188)Re] rhenium-ethylene dicysteine (Re-Ec): preparation and evaluation for possible use in endovascular brachytherapy

188ReO(4)(-), (188)Re-MAG(3), and (188)Re-DTPA are currently under investigation as radiation sources in liquid-filled balloons for prevention of restenosis following coronary angioplasty. Because (99m)Tc-labeled ethylene dicysteine (EC) is a well-established agent for renal tubular function imaging, the use of [(188)Re] rhenium-labeled EC as a potential agent for prevention of restenosis after angioplasty is worth evaluation. In this article, the preparation and pharmacological behavior of [(188/186)Re]Re complex of EC are reported. The yield of the Re complex was optimized by varying the parameters of complexation. The complex prepared under the optimized conditions was found to be stable over a period of 7 days when stored at pH 2 and at 4 degrees C. The pharmacological behavior of [(188/186)Re]Re-EC confirms its similarity to (188)Re-MAG(3) and its superiority over (188)ReO(4)(-) for use in endovascular brachytherapy.

Validation of a Bengali adaptation of the Conners' Parent Rating Scale (CPRS-48)

BACKGROUND

The Conners' Parent Rating Scales (CPRS) have been used to measure behavioural problems in drug trials in children for many years. This study in rural India aimed to validate a translated version of the CPRS-48 for use in a study of anti-epileptic drug side-effects.

METHOD

The Scale was translated into local dialect, back-translated, and piloted among healthy families. The revised version was then administered to mothers of 60 healthy children and 63 children with epilepsy. Tests of internal reliability, test-retest reliability and factor analysis were performed.

RESULTS

Cronbach's alpha ranged from 0.60 to 0.75 for the subscales, and correlation coefficients after retesting from 0.84 to 0.99. The overall factor structure was very similar to that reported in the original USA sample.

CONCLUSION

The Bengali version of the CPRS-48 and its Hyperactivity Index have validity for rural Bengali children, and the process demonstrates that such instruments can be usefully adapted for local purposes.

Protection by protein A of apoptotic cell death caused by anti-AIDS drug zidovudine

Zidovudine, the anti-AIDS drug, caused inhibition of mitogen-induced proliferation and perturbation of cell-cycle progression of cultured bone marrow cells of mice. There was significant hypoploidy observed in flow cytometric analysis of AZT-treated bone marrow cells. In apo-direct analysis, cells showed apoptosis in G0/G1 phase. In DNA gel analysis, characteristic laddering of apoptosis was observed in AZT-treated bone marrow cells. We demonstrated that, when the animals were pretreated with protein A (PA) of Staphylococcus aureus, the apoptotic changes could be prevented in bone marrow cells of AZT-treated animals. There is a significant (p < 0.05) increase in proliferation of bone marrow cells subjected to mitogen treatment in PA+AZT-treated animals, compared to only AZT-treated animals. However, cell-cycle phase distribution was not hampered and no laddering in DNA gel analysis was also observed in this group. In apo-direct analysis, PA treatment showed significant (p < 0.001) inhibition of AZT-induced apoptosis. These observations indicate that by using a suitable agent such as protein A the toxic side effects of AZT could be minimized.

Genetic disorders of vision revealed by a behavioral screen of 400 essential loci in zebrafish

We examined optokinetic and optomotor responses of 450 zebrafish mutants, which were isolated previously based on defects in organ formation, tissue patterning, pigmentation, axon guidance, or other visible phenotypes. These strains carry single point mutations in >400 essential loci. We asked which fraction of the mutants develop blindness or other types of impairments specific to the visual system. Twelve mutants failed to respond in either one or both of our assays. Subsequent histological and electroretinographic analysis revealed unique deficits at various stages of the visual pathway, including lens degeneration (bumper), melanin deficiency (sandy), lack of ganglion cells (lakritz), ipsilateral misrouting of axons (belladonna), optic-nerve disorganization (grumpy and sleepy), inner nuclear layer or outer plexiform layer malfunction (noir, dropje, and possibly steifftier), and disruption of retinotectal impulse activity (macho and blumenkohl). Surprisingly, mutants with abnormally large or small eyes or severe wiring defects frequently exhibit no discernible behavioral deficits. In addition, we identified 13 blind mutants that display outer-retina dystrophy, making this syndrome the single-most common cause of inherited blindness in zebrafish. Our screen showed that a significant fraction (approximately 5%) of the essential loci also participate in visual functions but did not reveal any systematic genetic linkage to particular morphological traits. The mutations uncovered by our behavioral assays provide distinct entry points for the study of visual pathways and set the stage for a genetic dissection of vertebrate vision.

Mechanisms of protein A superantigen-induced signal transduction for proliferation of mouse B cell

Apart from many of the biological properties of protein A (PA) of Staphylococcus aureus, it has been recognized recently as a B-cell superantigen. Therefore, we investigated the molecular mechanisms of PA superantigen-induced mice splenic B-cell proliferation. Treatment of resting B cells with PA-evoked cell proliferation. Binding of PA to B cells led to a cascade of signal transduction mechanisms involving tyrosine kinase that activated phospholipase C, which in turn activated protein kinase C (PKC), and translocated it from cytosol to membrane. Mitogen-activated protein (MAP) kinase has been found to be activated down-stream of PKC in this signal pathway, which ultimately caused an activation of serum-responsive factor (SRF). Inhibition at any step of this signaling cascade could block B-cell proliferation. PA could also stimulate the Bcl-2 gene expression at protein level thereby supporting the pro-proliferative effect of PA. Thus, the molecular mechanisms related to PA-induced B cell proliferation has been delineated in this report as tyrosine kinase > PLC > PKC > MAP kinase > SRF > Bcl-2. Knowledge gathered from these observations might be of immense help to study the immune cell proliferation as a part of immunoactivation process. Also, the development of suitable inhibitors of the signaling pathway outlined here might provide clues as to how to abrogate pathologic antibody production in many disease processes.

Role of intravitreal dexamethasone in exogenous fungal endophthalmitis

PURPOSE

To determine the effects of intravitreal dexamethasone in patients with exogenous fungal endophthalmitis.

METHODS

Twenty cases of culture-proven exogenous fungal endophthalmitis following cataract surgery (11/20) and trauma (9/20) were retrospectively analysed for pre- and postoperative visual acuity, anterior chamber and vitreous inflammation and media clarity. All patients were managed with pars plana vitrectomy with intravitreal amphotericin B and oral ketoconazole with (steroid plus group) or without (steroid minus group) intravitreal dexamethasone. Results were analysed by Fisher's exact test.

RESULTS

Following vitrectomy 9 of 20 patients (45%) achieved a visual acuity better than counting fingers at 3 m. No statistically significant difference was observed in anatomical and visual outcome between the steroid plus and steroid minus groups, though the number of patients with favourable visual outcome was greater in the steroid plus group. Rate of clearance of inflammation was better in the steroid plus group (40 +/- 15.5 vs 55 +/- 8.6 days). All patients (6/20) with pre-operative vision better than counting fingers showed good anatomical and visual outcome in both groups.

CONCLUSIONS

The results of our retrospective study suggest that steroids may be beneficial in promoting faster clearance of inflammation in fungal endophthalmitis. Sensitivity of the fungi to antifungals, dose and timing of steroid and institution of effective antifungal medication prior to the use of steroids are the essential factors which need to be examined further in a prospective manner.

Intravitreal dexamethasone in exogenous bacterial endophthalmitis: results of a prospective randomised study

AIM

To evaluate the efficacy of intravitreal dexamethasone co-administered with intravitreal antibiotics along with vitrectomy in the management of exogenous bacterial endophthalmitis.

METHODS

In a prospective randomised clinical trial, 63 patients (63 eyes) with suspected bacterial endophthalmitis (postoperative and post-traumatic) were treated with vitrectomy and intravitreal antibiotics and randomised to intravitreal dexamethasone (IOAB with = 29 eyes) and no dexamethasone (IOAB without = 34 eyes). Inflammation score (IS) and visual acuity were measured by two masked observers before surgery, and at 1, 4, and 12 weeks after surgery in both the groups.

RESULTS

There was significant reduction (p <0.0001) in IS at 1, 4, and 12 weeks after the surgery in the "IOAB with" group; there was temporary but significant increase (p <0.01) in IS at 1 week in the "IOAB without" group, before decline (p <0.001) of IS at 4 and 12 weeks. The magnitude and relative percentage change in IS between the two groups were found to be significant at 1 (p <0.0001), and 4 (p <0.01) weeks, and not at 12 weeks. The visual acuity at 12 weeks was comparable in both the IOAB with and IOAB without groups.

CONCLUSION

Intravitreal dexamethasone helps in early reduction of inflammation in exogenous bacterial endophthalmitis, but has no independent influence on the visual outcome. In selected patients with endophthalmitis where oral corticosteroids cannot be given for medical reasons intravitreal corticosteroids could be beneficial; in other situations they could be complementary to oral corticosteroid therapy.

Microbiologic spectrum and susceptibility of isolates: part I. Postoperative endophthalmitis. Endophthalmitis Research Group

PURPOSE

To present the microbial spectrum and susceptibilities of isolates in postoperative endophthalmitis.

METHOD

Isolates from 206 eyes of 206 patients who underwent vitrectomy for postoperative endophthalmitis were examined.

RESULTS

One-hundred twelve (54.4%) of 206 vitreous samples were culture positive and 14 (12.5%) of 112 culture-positive cases were polymicrobial, yielding a total of 126 isolates. Isolates included 59 (46.8%) gram-positive cocci, eight (6.3%) gram-positive bacilli, 33 (26.2%) gram-negative organisms, five (4.0%) Actino-mycetes-related organisms, and 21 (16.7%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported.

CONCLUSIONS

This is the largest, single-center, prospective series on microbial susceptibilities in postoperative endophthalmitis. We report a high prevalence of gram-negative species and fungi, suggesting that empiric therapy should include coverage for gram-negative pathogens and for fungal pathogens in appropriate settings.

Basic fibroblast growth factor stimulates cytosolic phospholipase A2, phospholipase C-gamma1 and phospholipase D through distinguishable signaling mechanisms

Fibroblast growth factors (FGFs) stimulate proliferation, differentiation and motility of different cell types. The cellular effects of FGF are transduced by its interaction with any one of four members of a family of high affinity, cell surface FGF receptors (FGFRs) that have autophosphorylating tyrosine kinase activity. Activation of FGFR causes release of various low molecular weight signaling molecules which are required for the pleotropic effects of FGFs. We report here that basic FGF plays critical role in membrane phospholipid hydrolysis in NIH 3T3 cells that are stably transfected with FGFR1. Upon binding to FGFR1, basic FGF stimulates cytosolic form of phospholipase A2 (cPLA2), phospholipase C-gamma1 (PLC-gamma1) and phospholipase D (PLD), the key enzymes for the production of various lipid second messengers, in a tyrosine kinase-dependent manner. In addition to tyrosine phosphorylation, cPLA2 catalytic activation requires serine phosphorylation by p42 mitogen-activated protein (MAP) kinase and possibly pertussis toxin-sensitive G-protein coupling. On the other hand, phosphatidyl inositol 4,5 bisphosphate (PIP2) hydrolysis requires direct phosphorylation at tyrosine residue of the PLC-gamma1 isozyme. The activation of PLD needs direct or indirect receptor tyrosine kinase and protein kinase C (PKC) activities. Additionally, it also requires botulinum toxin C-sensitive Rho-like G-protein activation. All these results suggest that the pleotropic effects of FGF are exerted through its tyrosine kinase receptors and individual effectors are activated via distinguishable signaling mechanisms according to the cell's need.

Microbiologic spectrum and susceptibility of isolates: part II. Posttraumatic endophthalmitis. Endophthalmitis Research Group

PURPOSE

To present the microbial spectrum and susceptibilities of isolates in posttraumatic endophthalmitis.

METHOD

Isolates from 182 eyes of 182 patients who underwent vitrectomy for posttraumatic endophthalmitis were examined.

RESULTS

One hundred thirteen (62.1%) of 182 vitreous samples were culture-positive, and 23 (20.4%) of 113 culture-positive cases were polymicrobial, including three (2.7%) trimicrobial cases, yielding a total of 139 isolates. Isolates included 63 (45.3%) gram-positive cocci, 24 (17.3%) gram-positive bacilli, 25 (18.0%) gram-negative organisms, seven (5.0%) Actinomycetes-related organisms, and 20 (14.4%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported.

CONCLUSIONS

This study represents a large series on microbial spectrum and susceptibilities in posttraumatic endophthalmitis. We report a high prevalence of gram-positive bacilli species and polymicrobial infections containing gram-negative species, underscoring the importance of broad-spectrum, combination antibiotics in the empiric treatment of posttraumatic endophthalmitis.

Optimal replication activity of vesicular stomatitis virus RNA polymerase requires phosphorylation of a residue(s) at carboxy-terminal domain II of its accessory subunit, phosphoprotein P

The phosphoprotein, P, of vesicular stomatitis virus (VSV) is a key subunit of the viral RNA-dependent RNA polymerase complex. The protein is phosphorylated at multiple sites in two different domains. We recently showed that specific serine and threonine residues within the amino-terminal acidic domain I of P protein must be phosphorylated for in vivo transcription activity, but not for replication activity, of the polymerase complex. To examine the role of phosphorylation of the carboxy-terminal domain II residues of the P protein in transcription and replication, we have used a panel of mutant P proteins in which the phosphate acceptor sites (Ser-226, Ser-227, and Ser-233) were altered to alanines either individually or in various combinations. Analyses of the mutant proteins for their ability to support replication of a VSV minigenomic RNA suggest that phosphorylation of either Ser-226 or Ser-227 is necessary for optimal replication activity of the protein. The mutant protein (P226/227) in which both of these residues were altered to alanines was only about 8% active in replication compared to the wild-type (wt) protein. Substitution of alanine for Ser-233 did not have any adverse effect on replication activity of the protein. In contrast, all the mutant proteins showed activities similar to that of the wt protein in transcription. These results indicate that phosphorylation of the carboxy-terminal domain II residues of P protein are required for optimal replication activity but not for transcription activity. Furthermore, substitution of glutamic acid residues for Ser-226 and Ser-227 resulted in a protein that was only 14% active in replication but almost fully active in transcription. Taken together, these results, along with our earlier studies, suggest that phosphorylation of residues at two different domains in the P protein regulates its activity in transcription and replication of the VSV genome.

Induction of cell proliferation and apoptosis: dependence on the dose of the inducer

Protein A (PA) of Staphylococcus aureus is known as an immunomodulator. In a search of the molecular mechanism(s) of PA-induced immunocyte potentiation, we found dose-dependent binding of PA (0.01 to 100 microg/ml PA) to the mice splenic lymphocytes. Interestingly, treatment of 1 microg PA/20 g mice increased the splenic lymphocyte number approximately 5-fold over control but at a 10-microg dose the cell number was decreased compared with a 1-microg dose. Flow cytometric analysis of cell-cycle phase distribution of nuclear DNA in splenic lymphocytes showed that at a 1-microg dose, PA shifted the cell-cycle phases from G0/G1 to S and G2/M supporting the pro-proliferative role of PA. In contrast, the same inducer increased the sub-G1 cell population at a 10-microg dose indicating the breakdown of cellular DNA. These findings were supported by DNA ladder formation and nuclear breakdown at this higher dose. Further studies revealed that at a 1-microg dose, the level of the pro-proliferative/anti-apoptotic protein bcl-2 was increased in splenic lymphocytes whereas at a 10-microg dose it showed a decreasing trend. In contrast, concentrations of proapoptotic proteins, p53 and bax, were increased at a 10-microg dose. A search of the mechanism(s) of such differential action of PA at these two doses revealed that the lower dose of PA upregulated the production of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) to the extent which has already been reported by our laboratory to be beneficial to the host. However, at a larger dose, much higher release of TNF-alpha and interleukin-2 (IL-2) may account for the apoptosis of splenic cells. All these findings indicated that the cross-talk between all these pro- and anti-apoptotic factors may contribute to maintain a balance between growth and death of cells and may be one of the important factors deciding whether a cell would follow a proliferative pathway or an apoptotic pathway.

Hypodermic needles: a new source of penetrating ocular trauma in Indian children

PURPOSE

To study the clinico-microbiologic profile and visual prognosis of ocular injuries caused by disposable hypodermic needles used by children to squirt water.

METHODS

We analyzed 19 consecutive cases of hypodermic needle injury seen at our institute.

RESULTS

The average age of the patients was 10.3 years (range, 4-20 years). A small self-sealed corneal or scleral laceration was seen in 11 eyes; in 8 eyes, the site of injury was occult. Initial visual acuity was no light perception (3 eyes) or hand motion or light perception (16 eyes). Surgery in 18/19 eyes included vitrectomy with intraocular antibiotic injections for endophthalmitis (14 eyes), evisceration for panophthalmitis (2 eyes), and cataract extraction for traumatic cataract (2 eyes). Final visual acuity was no light perception or light perception only in 10 eyes, 20/400-20/60 in three eyes, and 20/40 or better in six eyes.

CONCLUSIONS

Severe ocular morbidity may result from improper disposal of hypodermic needles.

Carboxy-terminal five amino acids of the nucleocapsid protein of vesicular stomatitis virus are required for encapsidation and replication of genome RNA

The encapsidation of vesicular stomatitis virus (VSV) genome RNA, a prerequisite step to the replication process by the nucleocapsid protein (N) was studied by its ability to package VSV leader RNA in vitro in a RNase-resistant form. The VSV leader RNA was derived from the SP6 transcription vector while the N protein was made in rabbit reticulocyte lysate. The in vitro encapsidation was carried out by translating N mRNA in the presence of 32P-labeled presynthesized leader RNA. The RNA encapsidation property of the N protein was completely abrogated when the C-terminal five amino acids (VEFDK-COOH) were deleted. Systematic mutational analyses within the C-terminal five amino acid regions reveal that the RNA encapsidation activity was lost in all mutants except K --> A and K --> R, indicating that C-terminal five amino acids, in particular the lysine residue play critical role in genome RNA encapsidation. To correlate the in vitro encapsidation abilities of these mutant N proteins with genome RNA replication, we have used a full-length cDNA clone of VSV genome RNA to rescue infectious virions from cells expressing L, P, and wt or mutant N proteins and measured the recovery of plaque forming units. The results indicate that the N mutants that are defective in in vitro encapsidation of leader RNA do not support replication, establishing the requirement of C-terminal five amino acids of the N protein in viral replication.

The transplantation of human fetal neuroretinal cells in advanced retinitis pigmentosa patients: results of a long-term safety study

The purpose of this study was to determine the long-term safety of transplanting human fetal neuroretinal cells (14 to 18 week gestational age) into a series of patients with advanced retinitis pigmentosa (RP). After obtaining informed consent, both hosts and mothers of donors were screened for transmissible diseases. Pre- and postoperative clinical exams, visual acuity, electroretinograms, and fluorescein angiograms were performed and visual field testing was attempted in each case. Surgically, an anterior approach through pars plana ciliaris was used. A retinotomy was performed in the paramacular area and a two-function cannula was introduced into the subretinal space to deliver a suspension of donor cells. The cell suspension carried approximately 4000 cells/microl; the volume injected did not exceed 150 microl. The patients were examined for periods ranging from 12 to 40 months posttransplantation. To date, no evidence of inflammation, infection, or overt rejection of the graft was noted in the host eye, neither was any change observed in the contralateral, unoperated eye. In conclusion, neuroretinal cells were injected into the subretinal space of 14 patients with advanced RP with no clinical appearance of detrimental effects at the time of surgery or up to 40 months postinjection except in 1 patient who developed retinal detachment. This sets the stage for a phase II clinical trial to determine the possible beneficial effects of this procedure in patients blinded by degenerative retinal disease.

Protein A of Staphylococcus aureus evokes Th1 type response in mice

Protein A (PA) of Staphylococcus aureus is known to elicit several cytokines such as IFN gamma, TNF alpha and IL1. However, it has not been delineated yet as to which differentiation pathway lymphocytes follow after stimulation by PA. In this report, we attempted to collect such evidences. Cytokines, such as IFN gamma, IL2, IL4, IL6, IL10, TNF alpha, IL1alpha and IL1beta were measured in serum by ELISA. Our results show that 1 microg dose of PA stimulates the production of IFN gamma (115 +/- 5 pg/ml), TNF alpha (250 +/- 8 pg/ml) and IL1alpha (100 +/- 5 pg/ml) as compared to control levels of, 22 +/- 2, 20 +/- 2 and 35 +/- 3 pg/ml respectively whereas IL2 and IL1beta secretion were less (beyond the lower detection limit of the kit and 25 +/- 1 pg/ml, respectively) as compared to control (28 +/- 2 and 52 +/- 4 pg/ml, respectively). Larger dose of PA (10 microg) increases the expression of IL2 (75 +/- 3 pg/ml), TNF alpha (1380 +/- 120 pg/ml), IL1alpha (495 +/- 10 pg/ml) and IL1beta (110 +/- 7 pg/ml) as compared to controls described above. We also observed that 1 microg dose of PA decreases IL4, IL6 and IL10 secretion to 9 +/- 1, 10 +/- 1 and 10 +/- 2 pg/ml, respectively, whereas 10 microg dose also decreased them to 11 +/- 1, 12 +/- 2 and 30 +/- 4 pg/ml, respectively as compared to the background controls, i.e. 50 +/- 5, 50 +/- 2 and 215 +/- 9 pg/ml respectively. The ratio of IFN gamma to IL4 increased and the peak value at 4 h, came to 13 +/- 1 and 9.6 +/- 0.5 with 1 microg and 10 microg PA, respectively, which is an established parameter indicating a Th1 type response. Flow cytometry analysis of CD4+/CD8+ cells, and c-myc protein expression by splenocytes indicate that 1 microg dose of PA causes 2-fold increase of CD4+ cells with no change in CD8+ cells, and 10-fold increase in c-myc protein, whereas 10 microg dose increases CD4+ cells 4-fold, CD8+ cells 3-fold and c-myc protein 100-fold. The cell cycle data shows an induction of apoptosis in thymocytes and splenocytes with the large dose (10 microg), whereas the 1 microg dose does not show any apoptosis. This report indicates that a Th1 response is induced in mice, after PA inoculation at a dose of 1 microg animal. Thus, cytokine mediated therapeutic strategies should consider the fact that an induction of large concentration of some cytokines might become detrimental to the host.

S. aureus superantigen protein A expands CD4(+)/CD8(+)/CD19(+)/CD34(+) cells in mice: a potential immunorestorer

Protein A (PA) of Staphylococcus aureus is known for its immunostimulatory, anti-cancer, and anti-toxic properties. The present study revealed that PA stimulates specific immunocytes to act as a potential immunorestorer. It has also been shown that the percentage of various cell types bearing different clusters of differentiation markers, e.g., CD4(+), CD8(+), CD19(+), increases considerably after inoculation with PA. It has also been observed that CD34(+) progenitor cells of bone marrow also increased significantly (P < 0.05) upon PA treatment. PA significantly elevated Th-1 cytokines, e.g., IFN-gamma, TNF-alpha, and IL-1alpha. The increased percentages of CD4(+), CD8(+), CD19(+), CD34(+) cells and elevated cytokine levels in PA treated animals may contribute to the reported anti-tumor, anti-fungal, anti-parasitic, and anti-toxic properties of PA. Since in various diseased conditions and during toxic drug therapy lymphocytes bearing such differentiation markers get suppressed, this type of approach could help in immunorestoration of the host. These findings might help in designing therapeutic approaches toward various diseases which cause immunosuppression.

Endoscopic variceal ligation for primary prophylaxis of oesophageal variceal bleed: preliminary report of a randomized controlled trial

BACKGROUND

Prevention of variceal bleeding, a major cause of morbidity and mortality, is an important goal in the management of patients with portal hypertension (PHT). Although propranolol has been found useful in preventing the first episode of variceal bleeding (primary prophylaxis) in cirrhotic PHT, it has limitations which include side effects, contraindications, non-compliance and failure in some patients. Endoscopic variceal ligation (EVL) has not been used for primary prophylaxis.

METHODS

Thirty cirrhotic patients with PHT, grade III to IV oesophageal varices, hepatic venous pressure gradient > or = 12 mmHg and no prior history of upper gastrointestinal bleeding were randomized to receive propranolol (to reduce their pulse rate by 25% from baseline, n = 15) and EVL (weekly to fortnightly until variceal eradication, n = 15). The two groups were comparable. All the patients in EVL group had variceal eradication during 3.8 +/- 2.2 sessions.

RESULTS

There was no major complication or interval bleeding. During a follow-up period of 17.6 +/- 4.7 months, varices recurred in three, two of which bled (successfully treated by EVL). In contrast, during this period of follow up one patient in the propranolol group had variceal bleeding (P=NS). Side effects of propranolol included symptomatic bradycardia requiring reduction of dose in one of 15 patients.

CONCLUSIONS

Although sample size in this study is small, it seems that EVL may be a good option for primary prophylaxis for variceal bleeding in patients with cirrhotic PHT; further studies on a larger number of patients and longer follow up are required.