Characterization of the pecT control region from Erwinia chrysanthemi 3937

Erwinia chrysanthemi synthesizes and secretes pectate lyases that attack components of the plant cell wall and, therefore, play a major role in the pathogenesis of soft rot disease. We isolated a new mutant (designated pec-1), by Tn5 mutagenesis, that displays weak pectate lyase production and decreased motility and mucoidicity. Maceration and pathogenicity tests done on different plant organs showed that the pec-1 strain displays a reduced virulence compared to that of the parental strain. The Tn5 insertion was localized between the pelL and the out loci and defines a new regulatory region. Sequencing of the pec-1::Tn5 insertion revealed that pec-1 is tightly linked to the pecT regulatory gene that also controls pectate lyase synthesis. Moreover, the pecT mutation is dominant over the pec-1 mutation, suggesting that these two loci are involved in the same regulatory network. We demonstrated, by Northern blot analysis, that the pec-1::Tn5 insertion provokes derepression of pecT transcription and defines a cis-acting element. Introduction of the pecT gene in trans of a pecT::uidA fusion induced a decrease of pecT::uidA transcription, indicating a negative autoregulation. Band shift experiments confirmed that the PecT repressor specifically interacts with the pecT regulatory region. We also demonstrated that the PecT protein interacts with the regulatory region of the pelD gene encoding a pectate lyase. Therefore, the abolition of the pecT autoregulation in the pec-1 mutant provokes an overproduction of the PecT repressor that is responsible for the decrease of pectate lyase synthesis. Mutagenesis of the pecT regulatory region revealed the presence of two sites in which insertions reproduced the pec-1 phenotype. This result suggests that pecT autoregulation requires the presence of two functional operator sites. From this study, we propose that the PecT repressor binds to these two sites, generating a loop that blocks pecT transcription.

Deposits of topical norfloxacin in the treatment of bacterial keratitis

PURPOSE

Fluoroquinolone solutions are widely used in therapy of bacterial keratitis. These drugs are safe, and their ocular side effects are mild and not serious in nature. The most frequent untoward effect associated with ciprofloxacin therapy has been a white crystalline deposit. This deposit has not been reported after using the other commercially available quinolones, ofloxacin and norfloxacin.

METHODS

We present three cases of norfloxacin deposits after treatment of bacterial keratitis.

RESULTS

In the three cases, the norfloxacin was substituted for another antibiotic effective against the bacteria, and the precipitate spontaneously resolved in all cases within a few days with no untoward ocular effect.

CONCLUSION

Crystalline corneal deposits can develop during topical norfloxacin therapy. The exact factors contributing to the formation are unknown, although the differences in the tear pH/solubility could be involved. Clinicians should be aware of this ocular side effect.

[Post-infectious demyelinating diseases]

Post-infectious demyelinating disorders are uncommon. In the Hospital Pediatrico de la Misericordia de Santafé de Bogotá there were 14 cases in three years. The commonest age group was the new born, as is found in the literature. The infections involved in these neurological changes are probably viral, since at the time the patient is seen most symptoms have cleared up spontaneously. According to several authors, the viruses are most often found to be those of measles or mumps. Between the infection and the development of neurological symptoms there is an interval of approximately two weeks. The main clinical findings are motor changes such as hemiparesis, involvement of cranial nerves and alterations of consciousness. The aetiology is not completely clear. Firm diagnosis is made on histopathological studies which are seldom available. Usually neuroimaging techniques and cerebrospinal fluid analysis are the basis of the diagnosis. Computerized axial tomography and magnetic resonance are the most useful noninvasive techniques for assessing the involvement of the white matter, the extent and sites of the lesions. It is useful to know the classification of the demyelinating disorders so as to prescribe, the most suitable treatment and give the prognosis in each case. There is still no specific treatment for these disorders. Supportive measures, the control of epileptic crises and the prevention of complications are the main aims. This paper reviews the definition, classification, diagnosis and management of these disorders.

Early versus late necrosectomy in severe necrotizing pancreatitis

BACKGROUND

Debate as to whether surgery in severe necrotizing pancreatitis (SNP) should be done early or late has been present ever since the disease was described. There are no prospective, randomized studies addressing this specific issue.

METHODS

Patients with SNP, documented clinically, with Ranson's criteria, and dynamic pancreatography (DP) findings were randomly allocated in two groups for treatment. Group A included early necrosectomy (within 48 to 72 hours of onset) and group B, late necrosectomy (at least 12 days after onset). Both groups continued with open packing and staged necrosectomies. Cultures were obtained at each laparotomy and necrosis was verified histologically in all instances.

RESULTS

During a 36-month study period, 150 patients with unequivocal acute pancreatitis were admitted for treatment. Forty-one with SNP initially entered the study; there were 5 drop outs. Patients in group A (25) and group B (11) had no difference in distribution by gender or mean age, etiology, mean Ranson's signs (4 versus 3.8), DP findings, rate of infected necrosis, or necrosectomies required per patient. Although the mortality rate (58% versus 27%) did not reach statistical significance, the odds ratio for mortality was 3.4 times higher in group A, which made us finish the study.

CONCLUSION

This prospective, randomized study from a single institution clearly demonstrates that early intensive conservative treatment with late necrosectomy for selected cases is the current rationale approach for SNP.

Urodynamically based modification of Mitrofanoff procedure

This paper reviews our experience with the Mitrofanoff principle as applied in eight patients. Of four patients with post-traumatic urethral stricture, three required the appendix as continent catheterizable conduit, with a modified appendicovesical anastomosis technique-that is, without a submucosal tunnel- and in one patient, the remnant ureter of a previous simple nephrectomy was used. Of the four remaining patients, one with a hypotonic bladder and three with urethral stricture, a complete laparoscopic approach was used to perform the same modified Mitrofanoff procedure with the appendix. With a mean follow-up of 19.5 months, all patients were completely dry. Only three patients had persistently positive urine cultures, but without evidence of renal function impairment. The modified direct appendicovesical anastomosis technique reduces the operative time, has a lower complication rate, and allows us to use a laparoscopic approach with the resulting benefits of a minimally invasive surgical procedure. As shown in urodynamic tests, urinary continence is preserved.

Management and Treatment of Central Steep Islands after Excimer Laser Photorefractive Keratectomy

BACKGROUND

Permanent central steep islands are an undesirable phenomenon that cause distorted images and a significant reduction in visual acuity. We describe treatment of central steep islands with repeat excimer laser photoablation in the central cornea.

METHODS

Three patients with preoperative refractions of -7.50 -2.50 x 170 degrees D (right eye), -8.00 -2.25 x 10 degrees D (right eye) and -6.00 -1.50 x 90 degrees (right eye) developed central steep islands which persisted more than 12 months. All patients lost more than two lines of spectacle-corrected visual acuity and complained of visual disturbances. We retreated the central steep islands with a VISX 20/20 excimer laser PRK ablation that matched the size of the central island measured on videokeratography.

RESULTS

Symptomatic glare and distortion were significantly reduced and the central steep islands were resolved. Several weeks after reablation, spectacle-corrected visual acuity improved to the preoperative level.

CONCLUSION

Central steep island, an infrequent complication of excimer laser photorefractive keratectomy, can be safely removed with a repeat laser ablation that matches the central circular steep area.

Tissue distribution and structure of barrier cells in the hematopoietic and lymphoid organs of salmonids

BACKGROUND

Barrier cells have been recognized as a discrete group of fibroblastic- or myofibroblastic-like cells located in the lymphoid and hematopoietic organs of mammals. This paper reports the results of a morphological study of the main lymphoid organs of three salmonid species, in which cells structurally similar to the mammalian barrier cells were observed in healthy animals.

METHODS

The spleen, kidney, and thymus of fingerlings of rainbow trout, Oncorhynchus mykiss, and Coho salmon, Oncorhynchus kisutch, and of adult brown trout, Salmo trutta fario, were processed for electron microscopy study using various fixation methods. Semithin sections were used for the Periodic Acid-Schiff (PAS) staining technique, and for the demonstration of the endogenous peroxidase activity.

RESULTS

The kidney and spleen of all the species contained a variable, but usually low, number of electron-dense, elongated, and branched cells, ultrastructurally similar to the mammalian barrier cells. They also occurred in the thymus of some brown trout and Coho salmon, but not of rainbow trout. The electron density of this cell type was present after the various types of fixation procedures. They show numerous ribosomes, well-developed secretory organelles, electron-clear vesicles, large granules, and microfilaments. In all the salmonid species, barriers cells were positive for PAS staining and for endogenous peroxidase activity. A small number of barrier cells were in mitosis. In the different organs barrier cells appeared as isolated cells, or forming syncytial networks. They were found lining the blood sinusoids of the splenic red pulp and of the renal hematopoietic tissue, in the periellipsoidal sheaths, and closely associated with erythropoietic and plasmacytopoietic foci.

CONCLUSIONS

Our results demonstrate the presence of cells closely resembling mammalian barrier cells in the hematopoietic and lymphoid organs of salmonids. The structure and tissue distribution of the salmonid barrier cells are discussed in relation to the functional roles described for this cell type in mammals.

HLA-B27--associated uveitis presenting with diffuse vitritis

A 26-year-old man complained of a sudden decrease in vision in the left eye. He had a past medical history of pauciarticular juvenile rheumatoid arthritis with a positive HLA-B27 haplotype and negative antinuclear antibodies and later development of ankylosing spondylitis. His ocular history was unremarkable. An ophthalmic examination revealed a predominant diffuse vitritis (3+) in the left eye. The uveitis improved after treatment with topical and systemic steroids. Following an extensive clinical and laboratory evaluation, a final diagnosis of HLA-B27-associated uveitis was made. Although uncommon, diffuse vitritis can occur in the setting of this uveitis and may be a predominant symptom.

Analysis of the blood-retinal barrier: its relation to clinical and metabolic factors and progression to retinopathy in juvenile diabetics. A 4-year follow-up study

BACKGROUND

The study was carried out to evaluate the correlation between blood-retinal barrier (BRB) permeability and the development of diabetic retinopathy (DR) and to assess the metabolic and clinical factors related to DR over a 4-year period by means of vitreous fluorophotometry (VF).

METHODS

Thirty-five type I diabetics with no retinopathy, age 7-21 years (mean 14.32 +/- 2.1 years) were enrolled in this longitudinal study. Two visits included standard ophthalmological examination, fluorescein angiography and VF were performed, on entry into the study and 4 years later. The following risk factors in DR were analyzed: age, duration of diabetes, blood pressure, cholesterol, triglycerides, fasting blood glucose levels, glycosylated hemoglobin (HbA1c), insulin dose/kg body weight (IDBW), fructosamine and albuminuria. To estimate the BRB permeability we adopted the vitreous penetration ratio transmittance (VPRt) value.

RESULTS

At 4-year follow-up the mean VPRt had significantly increased. During that time 13 patients developed DR and their final mean VPRt was significantly higher than that in non-DR patients. Additionally, the initial mean VPRt was higher but not significantly so, in patients that later developed DR than in non-DR subjects. A constant linear correlation was found between VPRt and duration of diabetes, HbA1c and microalbuminuria.

CONCLUSION

VF is a quantitative method that could measure and predict the breakdown of the BRB before angiographic retinopathy in type I diabetics. The major clinical and metabolic factors related to alterations in the BRB are duration of diabetes, HbA1c and microalbuminuria.

Initial pH as a determining factor of glucose consumption and lactic and acetic acid production in oral streptococci

Lactic and acetic acid production was evaluated from six strains of oral streptococci, viz Streptococcus gordonii, Streptococcus mutans, Streptococcus oralis, Streptococcus salivarius, Streptococcus sanguis and Streptococcus sobrinus cultured in the presence of 1, 5, 10 mM glucose and without glucose, at initial pH values of 5, 5.5, 6 and 7. S. sobrinus and S. salivarius caused the greatest decreases in pH. At pH values of 5 and 5.5, lactic acid and acetic acid production in the species tested was discordant with residual glucose levels. Acid production from protein was especially great in S. mutans and S. salivarius.

Evaluation of the automicrobic system for the identification of Streptococcus mutans

The performance of the Automicrobic System with the Vitek gram-positive identification card (bioMérieux, France) in identifying strains of Streptococcus mutans was studied. Of 160 strains assayed, 72.5% were confirmed to be Streptococcus mutans; the remainder were identified as other species of streptocci (Streptococcus bovis, Streptococcus uberis, Streptococcus anginosus, Streptococcus sanguis I and II, Streptococcus intermedius, and Streptococcus constellatus).

Expansion of the seizure monitoring program. A collaborative approach

This article discusses an interdisciplinary total quality management (TQM) project that planned for the expansion of the seizure monitoring program on a neuroscience unit. The processes of education, bed management, and patient care were evaluated by a TQM group of staff nurses, unit leader, attending physicians, clinical nurse specialist, and technicians. Each participant identified actual and potential problems and their effects on the participant's area of care.

Influence of topical cyclosporine A and dissolvent on corneal epithelium permeability of fluorescein

The corneal stroma is the major barrier to penetration for the lipophilic Cyclosporine A (CsA) molecule and prevents the use of the common ophthalmic solvents. At present, corn oil, castor oil and olive oil are the three most commonly used vehicles. The aim of this study was to determine the effect that topically applied CsA dissolved in different oils has on corneal epithelial permeability measured by fluorophotometry. Forty healthy volunteers, with absence of ocular or systemic disease and not receiving topical or systemic drugs were enrolled. Measurements were taken before and 45 min after the instillation of 40 microliters of a 2% aqueous solution of sodium fluorescein without preservatives. Basal corneal permeability and the permeability 24 h after the instillation of 2% CsA-olive oil, olive oil alone, 2% CsA-castor oil, castor oil alone, 2% CsA-corn oil and corn oil alone, were calculated. To prepare the topical 2% CsA, a Sandimmun oral solution (Sandoz, Basel, Switzerland) was employed under sterile conditions. We found that epithelial permeability 24 h after the instillation of any CsA formulations or solvents increased more than 6.62 times (p <0.001). No differences in corneal permeability values were found between any of the CsA formulations and the vehicles. We conclude that oils used to dissolve CsA are mainly responsible for the increased corneal epithelial permeability. No differences were found in the effects of the tested solvents on corneal epithelial permeability.

Two different subpopulations of Ig-bearing cells in lymphoid organs of rainbow trout

In a previous report we described the existence of two structural and antigenic variants of light chains in serum trout Igs, defined by mAbs 2H9 and 2A1. In this report, we analyse the cell distribution, the "in vitro" kinetics of production, and the ontogenic appearance of these two variants. Both variants were already present at day 8 before hatching and their kinetics of appearance correlated with that of total Ig, showing a peak around hatching. These mAbs stained two distinct lymphoid cell populations in the pronephros, mesonephros, spleen, and peripheral blood. Both mAbs reacted with approximately 1% of thymocytes. The ratio between these two cell populations (2A1+/2H9+) was about 2/1 in the lymphoid organs analysed. No differences were found between the profiles of the "in vitro" production of these variants in pronephric cell cultures stimulated with LPS. In these cultures, the 2A1 and 2H9 Igs together accounted for 10-70% of the total trout Ig produced, suggesting the existence of at least one additional L chain variant.

Effects of subconjunctival methylprednisolone on the blood aqueous barrier following cataract surgery

The aim of this double-blind randomized study was to assess the effect of subconjunctival methylprednisolone hemisuccinate (MH) on the recovery of the blood aqueous barrier (BAB) following uncomplicated cataract surgery performed by the same surgeon in normal eyes. Fifty eyes of fifty patients (28 female, 22 male, mean age 72.3 +/- 11.2 years) were randomized into two groups: group 1 received a subconjunctival injection of MH (40 mg in 0.5 cc) at the end of the surgery and group 2 did not. All patients were free of other ocular or systemic diseases known to alter the BAB and were not taking any anti-inflammatory medications. Postoperative treatments were similar in both groups. The patients were submitted to laser flare photometry 30 minutes to one hour after mydriasis with a drop of tropicamide preoperatively and on the first, second and seventh day and then one month and six months following surgery. No difference in aqueous flare was seen between the two groups on any of postoperative visits. These data suggest that subconjunctival MH has no beneficial effect in postoperative BAB permeability following uncomplicated cataract surgery in normal eyes.

Effect of bendazac lysine on lens and retina in diabetics

The possible beneficial effects on the lens and retina which Bendazac Lysine may have in the treatment of adult diabetic patients were investigated. Twenty patients, ranging in age from 54.80 +/- 5.86 years old, were studied. The average duration of the diabetes was 11.32 +/- 4.10 years. Thirteen patients had background retinopathy. The metabolic controls carried out during the study were satisfactory (HbA1 < 11%). Bendazac Lysine (500 mg three times a day) was administered for 6 months. Blood-retinal barrier permeability (VPR and VPRt) and lens transmittance (t) were evaluated prior to and 6 months after treatment by fluorophotometry. No statistically significant differences between the pre- and post-treatment values of the retina permeability were observed, however, there was a statistically significant improvement (p < 0.05) (initial value: t = 0.813 +/- 0.040 and final value: t = 0.823 +/- 0.037) in the lens transmittance. The authors conclude that Bendazac Lysine has a beneficial effect on the lens in the diabetic adult although no improvement in the permeability of the blood-retinal barrier has been observed.

Physiopathology of primary periodontitis associated with plaque. Microbial and host factors. A review. Part 2

To a considerable extent, host factors condition the initiation and progression of periodontitis. The integrity of the periodontal structures and the immune elements in the gingival fluid may act as a defensive barrier against microorganisms. However, immune over-response may lead to tissue damage and bone resorption from anaphylactic reactions, immunocomplex reactions, type IV hypersensitivity, complement hyperactivation via the alternative pathway, or direct action of leukocytes and macrophages. Moreover, insufficient host response allows bacteria to escape control, allowing more rapid progression of the disease.

Presence of double-stranded RNA and virus-like particles in Phaffia rhodozyma

Four double-stranded RNA (dsRNA) molecules were isolated from Phaffia rhodozyma UCD 67-385. Their molecular sizes were approximately 4.3, 3.1, 0.9 and 0.75 kilobase pairs (kbp) as determined by agarose-gel electrophoresis and they were designated as L, M, S1 and S2, respectively. By differential centrifugation in sucrose gradients, these dsRNAs copurified with isometric virus-like particles 36 nm in diameter. A cured strain, UV-S2, lacking the S2-dsRNA was obtained from P. rhodozyma UCD 67-385 by ultraviolet (UV) light treatment. UV-S2 strain contains identical virus-like particles to those from the wild-type strain, as determined by electron microscopy, suggesting that the S2-dsRNA was not essential for the expression of mycovirus structural polypeptides. On the other hand, both the UCD 67-385 and UV-S2 strains were able to kill P. rhodozyma UCD 67-383, a strain without dsRNAs. These results suggest that the dsRNA molecules also encode a killer system. Finally, the UV-S2 strain maintains killer ability, which suggests that S2-dsRNA is not involved in the killer phenotype expression.

Action of sodium fluoride on phagocytosis by systemic polymorphonuclear leucocytes

Alterations in phagocytosis appear to be important in the onset and development of periodontitis. We investigated new substances that may be of use in the treatment of periodontitis. In a preliminary study, we tested the effect of sodium fluoride on phagocytosis by circulating polymorphonuclear leucocytes (PMNs) in 10 replicate assays using blood from six healthy subjects. Sodium fluoride was tested at concentrations of 1.0 micron to 4.0 microns against Streptococcus oralis, Streptococcus mutans, Streptococcus sobrinus and Streptococcus sanguis. The phagocytic index against all microorganisms increased significantly at all concentrations of sodium fluoride assayed; this effect was dose dependent. Sodium fluoride appeared to stimulate phagocytosis via two mechanisms: an apparent increase in bacterial susceptibility to phagocytosis, and direct stimulation of phagocytosis by PMNs.

Respiratory arrest after 0.75% bupivacaine retrobulbar block

Respiratory arrest is an uncommon complication of retrobulbar anesthesia. We present a case in which it occurred following a 0.75% bupivacaine and 2% lidocaine retrobulbar block and analyze the possible causes. We conclude that the most important of these were the relatively high concentration and volume of the anesthetic and a faulty technique.

Physiopathology of primary periodontitis associated with plaque. Microbial and host factors. A review. Part 1

Microbial factors involved in the genesis of periodontitis include colonization, bacterial penetration of the epithelium, multiplication and invasive-destructive capacity. Colonization of the gingival sulcus is related, to a certain extent, to supragingival plaque. Bacterial multiplication is induced by nutrients in the gingival fluid, and nutrients produced by degradative and excretory microbial activity. Invasion and destruction are mediated by exotoxins, structural elements of the bacteria, enzymes, metabolites, polyclonal lymphocyte activity, fibroblastic cytotoxicity, and leukocyte chemotactic inhibition.

Persistent choroidopathy in systemic lupus erythematosus

We report a case of a rare entity, choroidopathy in association with systemic lupus erythematosus (SLE), previously described in only twelve patients to our knowledge. It manifested by multiple focal serous elevations of the sensory retina and/or serous detachments of the retinal pigment epithelium bilaterally. No retinal vascular changes were observed. The probable pathogenesis is related to choroidal vascular disease due to systemic hypertension secondary to lupus nephritis, vasculitis, or a combination of these.

Bacteriological indicators of faecal contamination: result of a loading experiment with untreated urban wastewater

Some observations were made on the behaviour of total coliforms, faecal coliforms, enterococci, numbers of aerobic bacteria, salmonellas and sulphur-reducing clostridia as bacterial indicators of faecal contamination of groundwater. A controlled irrigation experiment was carried out with untreated residual water in the alluvial aquifer of the Vega of Granada (Spain). The results obtained confirm the value of these parameters are useful indicators of very recent faecal contamination; and changes were detected as the level of the freatic layer increased and the chemical composition of the groundwater changed. These groups of micro-organisms persisted for about 200 h, with the exception of the aerobes which survived for much longer. Salmonellas were present at levels too low to calculate the extent of faecal contamination and sulphur-reducing clostridia were not detected. The results obtained show that irrigation with untreated wastewater offers a lower risk of microbiological contamination of groundwater compared with the direct addition of waters decanted and/or previously filtered.

A study on the antigenic nature of circulating immune complexes in hemolytic uremic syndrome: no evidence of platelet membrane glycoprotein antigens

Circulating immune complexes (CIC) have been described in the hemolytic uremic syndrome (HUS) in children. They may represent an epiphenomenon or could be related to the platelet activation and endothelial damage observed in this disease. In an attempt to define this relationship, we investigated the CIC isolated in 17 patients with the classic form of HUS, by means of monoclonal antibodies against platelet surface glycoprotein Ib and IIb-IIIa complex. The negative results obtained do not support the possibility of platelet antigens being constituents of CIC and make an antibody-induced platelet activation in HUS very unlikely.

The area under the function: an index for selecting desirable genotypes

The linear regression approach has been widely used for selecting high-yielding and stable genotypes targeted to several environments. The genotype mean yield and the regression coefficient of a genotype's performance on an index of environmental productivity are the two main stability parameters. Using both can often complicate the breeder's decision when comparing high-yielding, less-stable genotypes with low-yielding, stable genotypes. This study proposes to combine the mean yield and regression coefficient into a unified desirability index (D i). Thus, D i is defined as the area under the linear regression function divided by the difference between the two extreme environmental indexes. D i is equal to the mean of the i (th) genotype across all environments plus its slope multiplied by the mean of the environmental indexes of the two extreme environments (symmetry). Desirable genotypes are those with a large D i. For symmetric trials the desirability index depends largely on the mean yield of the genotype and for asymmetric trials the slope has an important influence on the desirability index. The use of D i was illustrated by a 20-environments maize yield trial and a 25-environments wheat yield trial. Three maize genotypes out of nine showed values of D i 's that were significantly larger than a hypothetical, stable genotype. These were considered desirable, even though two of them had slopes significantly greater than 1.0. The results obtained from ranking wheat genotypes on mean yield differ from a ranking based on D i .

[Use of a double-lumen tube with intermittent positive ventilation in a case of distal tracheal laceration]

We discuss the management of anesthesia in a patient brought to hospital following a traffic accident in which she suffered distal laceration of the trachea and unstable vertebral fracture that met surgical criteria. Our main objectives were to avoid placing positive pressure on the damaged trachea and to extubate immediately after surgery. Using a left double-lumen endotracheal tube guided by flexible bronchoscope, we administered general anesthesia with mechanical ventilation and positive pressure, with no air leakage through the damaged area. Anesthesia was maintained by continuous perfusion of propofol, allowing good hemodynamic stability and rapid extubation. We conclude that this will be a useful procedure in similar cases when no other form of mechanical ventilation is available.

An 18-month vitreous fluorophotometric follow-up study in juvenile diabetics

The authors assessed a fluorophotometry follow-up study of 18 months in 24 juvenile insulin-dependent diabetic patients with no retinopathy. The initial duration of diabetes was 5.96 +/- 3.44 years and the glycosylated hemoglobin (HbA1c) was 10.12 +/- 2.27%. The baseline Vitreous Penetration Ratio transmittance value (VPRt) was 4.13 +/- 1.31 x 10-6 min-1 and after 18 months was 5.36 +/- 1.85 x 10-6 min-1, yielding a statistically significant difference (p < 0.01). The average HbA1c during the follow-up term was 9.80 +/- 1.72%. VPRt values were significantly correlated with the duration of diabetes and HbA1c. During the follow-up 3 patients developed foveal background diabetic retinopathy with respect to a high initial VPRt value (6.22 +/- 0.27 x 10-6 min-1), nevertheless, the other 7 patients with high baseline VPRt did not do so. We suggest that vitreous fluorophotometry could be a beneficial procedure in the management of insulin-dependent diabetic patients; however, there is not a cut-off value for VPRt values to help distinguish patients prone to develop retinopathy.

Ontogeny of IgM and IgM-bearing cells in rainbow trout

We have studied the ontogenic development of immunoglobulin M (IgM) and of IgM-bearing cells in the rainbow trout, Oncorhynchus mykiss. Lymphocytes showing cytoplasmic IgM were first observed in embryos at 12 days before hatch (14 degrees C). At this stage, no cells positive for surface IgM were present. Lymphocytes bearing surface IgM were observed at 8 days before hatch (14 degrees C). Unfertilized trout eggs contained detectable amounts of IgM (11.2 +/- 2.6 micrograms/g of egg weight), indicating that transfer of IgM from mother to embryo can occur in salmonids. The levels of IgM from whole fish increase slowly after the appearance of intraembryonic cells that express surface IgM. The amount of IgM/g of tissue peaks around hatch, but this parameter shows lower values up to 2 months after hatch.

[Rapidly progressive glomerulonephritis without immune deposits: detection of neutrophil anticytoplasmic antibodies]

Antineutrophil cytoplasmic autoantibodies (ANCA), are serologic markers of disease in rapidly progressive glomerulonephritis without immune deposits (pauci-immune) and vasculitis, and could play a pathogenic role in these diseases. We communicate 5 patients with pauci-immune rapidly progressive glomerulonephritis; four of them in the evolution of necrotizing systemic vasculitis (Wegener's granulomatosis and microscopic polyarteritis) and one case with lesions limited to the kidney. All of them were associated with the presence of ANCA. The immunofluorescence pattern (cytoplasmic and perinuclear) and the antigenic specificity of ELISA assay, [antiproteinase-3 (PR-3) and antimyeloperoxidase (MOP)], are useful laboratory tools for the diagnosis and clinical management of these patients.

Clinical and metabolic factors associated with the blood retinal barrier permeability in insulin dependent diabetes mellitus without retinopathy

The authors assessed a study pointing out the relationship between the permeability of Blood Retinal Barrier (BRB), using vitreous fluorophotometry, and several risk clinical and laboratory data in Insulin Dependent Diabetes Mellitus (IDDM). Eighty eyes of 40 IDDM patients were evaluated. Their mean age was 14.8 +/- 3.2 years. Twenty healthy volunteers served as control group (mean age 15.3 +/- 3.2 years). Preexisting diabetic retinopathy was dismissed after funduscopy and fluorescein angiography. The studied risk factors were: age, duration of diabetes, HLA antigens, blood pressure, cholesterol and triglycerides levels, glycosylated hemoglobin, insulin dose/kg body weight and fructosamine. Vitreous and lens fluorophotometry was performed in both groups (VPRt). The mean VPRt in IDDM patients was 3.56 +/- 1.47 x 10(-6) min-1. In healthy subjects it was 2.53 +/- 0.55 x 10(-6) min-1, establishing a significant difference (p < 0.01). We found a statistically significant correlation between VPRt and duration of diabetes, insulin dose/kg body weight and HbAlc. No correlation was found between VPRt and the rest of parameters. We conclude that vitreous fluorophotometry is a valid method to measure BRB; and the three factors mentioned above are related to the BRB permeability.

[The use of ELISA and indirect immunofluorescence technics for the rapid detection of eastern equine encephalomyelitis]

We present the results attained in the identification of Eastern equine encephalomyelitis virus isolations in Vero and XL-2 cell systems, using a double-antibody ELISA technique and the indirect immunofluorescence method. The results attained through these two techniques coincided by 100% with identification through neutralization. With the former, the virus was detected within 6-8 hours after inoculation. Better results were attained with XL-2 cells.

Antineutrophil-cytoplasmic-autoantibodies in poststreptococcal nephritis

Sera from 210 patients with APSGN, were tested for the presence of ANCA (IgG-isotype). Indirect immunofluorescence (IF) on ethanol fixed human PMNs was used, and for those positive sera, ELISA kits for PR3 (Proteinase 3) and MPO (Myeloperoxidase) was performed. ANCA were detected in 9% (18 out of 210 cases) in a predominantly diffuse cytoplasmic staining pattern in 14 cases (77%), and in a perinuclear pattern in the remaining 4 cases (22%). Anti-MPO was found in 4 cases (C-ANCA 3; P-ANCA 1) and anti-PR3 was always negative. The presence of ANCA was significantly associated with a more severe glomerular disease as assessed by the serum creatinine value and the crescents formation. Longitudinal studies performed in 11 cases have shown that raised levels of these autoantibodies may persist for at least six months, without relationship with disease activity. Further studies are required to dilucidate the specificity of these autoantibodies, and if its presence is either an epiphenomenon of the heterogeneous humoral immune response in streptococcal infection, or they play some pathogenic role in APSGN.

In vitro immune modulation of polymorphonuclear leukocyte adhesiveness by sodium fluoride

We investigated the influence of sodium fluoride on polymorphonuclear leukocyte (PMN) adhesiveness in a healthy subject with low serum levels of fluoride. The PMN were separated from venous blood, and the percentages of adhered and unadhered cells were determined in vitro in plastic culture plates. The cells were cultured with five different fluoride concentrations ranging from 6.25 10(-2) microM to 4.0 microM in the presence and absence of autologous serum. PMN adhesiveness in both the presence and in the absence of autologous serum was 98.5%; the addition of fluoride had no effect on the results in the absence of serum. However, in the presence of autologous serum, PMN adhesiveness decreased significantly with the addition of fluoride (P < 0.05) from 0.5 microM. The decrease was smaller (1.1%) at a concentration of 0.125 microM, and larger at 12 times this concentration of fluoride (52.7%). We conclude that sodium fluoride reduces PMN adhesiveness in a dose-dependent manner. The effect is not direct, but should be modulated by a seric factor.

[Acute epiglottitis in adults]

The author presents the clinical history of 14 patients, from 21 to 48 years of age, 10 men and 4 women, with a final diagnosis of acute epiglottitis who were hospitalized at Gorgas Army Hospital or at the San Fernando Clinic. All the patients had pharyngitis and dysphagia, a few with nasal voice, stridor and difficulty breathing, as the chief complaint. All the patients were initially intubated orally for diagnostic purposes and immediately after nasotracheal intubation was done until the patient improved in 2 or 3 days (one patient remained intubated for 5 days). All patients were kept in the Intensive Care Unit and were treated with Ampicillin and Chloramphenicol IV and lately with a second generation cephalosporin (Cefamandole). The patients allergic to Penicillin were treated with Clindamycin and Chloramphenicol. Corticosteroids were not used in any of the patients. There were no sequelae and none of the patients expired.

Antimicrobial susceptibility of 1042 strains of Streptococcus mutans and Streptococcus sobrinus: comparison from 1985 to 1989

A total of 1042 strains of Streptococcus mutans and Streptococcus sobrinus isolated between 1985 and 1989 were tested to study the evolution of their sensitivity to penicillin, amoxycillin, amoxycillin/clavulanic acid, cefuroxime, tetracycline, erythromycin, spiramycin, acetyl spiramycin, lincomycin and clindamycin. The strains were taken from stock cultures and isolated from human saliva and dental plaque. The minimal inhibitory concentration (MIC) was determined by an agar dilution method. Except for spiramycin and acetyl spiramycin, all the antibiotics inhibited 100% of the strains with concentrations less than or equal to 2 micrograms/ml. Microorganisms from both species underwent a slow progressive loss of sensitivity to all the antibiotics over a 5-year period of study, showing statistically significant results in most cases.

[Pulmonary endometriosis. Clinical case]

Pulmonary endometriosis is a rare entity and there is little information regarding its treatment. We report a young female who developed hemoptysis in coincidence with menstruation. Pelvic endometriosis was confirmed histologically and pulmonary endometriosis was inferred. Treatment with Danazol led to suppression of both menstruation and hemoptysis, thus confirming the clinical diagnosis.

[Bacteremic meningoencephalitis due to Listeria monocytogenes in an immunocompetent adult]

A 34 year old non pregnant, immunocompetent female developed severe meningoencephalitis. Bacteriologic studies established listeria monocytogenes as the causative organisms. This agent, previously limited to affect immunocompromised hosts, has recently been shown to be transmitted by the oral route to immunocompetent persons. This is the first report of such case in Chile.

Post-hatching development of the thymic epithelial cells in the rainbow trout Salmo gairdneri: an ultrastructural study

This study reports the ultrastructure of subpopulations of epithelial cells of the thymic parenchyma during the post-hatching development of the rainbow trout, Salmo gairdner, kept at 14 degrees C. At hatching, the thymus contained a small number of medium and large thymocytes interspersed among three different types of epithelial cells: (1) epithelial cells adjacent to the connective tissue capsule; (2) ramified dark epithelial cells with electron-dense cytoplasm; and (3) pale electron-lucent epithelial cells displaying secretory-like features. All these cells types were anchored to one another by desmosomes and had apparently differentiated from the pharyngeal epithelium. At 4 days after hatching, the thymus enlarged, and numerous gaps occurred between the cell processes of contiguous epithelial cells adjacent to the capsular connective tissue. In 21-day-old trout, thymic trabeculae developed carrying blood vessels, and a subcapsular zone became evident containing lymphoblasts and large subcapsular epithelial cells. In 30-day-old trout, an outer thymic zone developed consisting of spindle-shaped epithelial cells which formed a dense network. At this stage, scattered cystic cells, which apparently differentiated from the pale epithelial cells, were present.

[Polymyalgia rheumatica as a form of presentation of systemic lupus erythematosus]

Three cases of systemic lupus erythematosus (SLE) with clinical presentation similar to a rheumatic polymyalgia (RP) are described. There was no evidence of underlying myopathy in any of the cases thus suggesting that the synovitis is the pathogenic mechanism. The late onset and the poor serologic expression are the relevant clinical signs which could delay or hinder the diagnosis.

[Chylous ascites secondary to a carcinoid tumor]

A 68-year-old male with abdominal swelling and wasting of one month's evolution had chylous ascites. The clinical study of the patient showed a retroperitoneal tumor and a distal jejunum and mesenterium affliction. There were metastatic nodules in peritoneum, epiploic appendix and malignant pleural effusion. The histological study showed a carcinoid tumor. Chylous ascites is an exceptional complication, and a bad prognosis factor of carcinoid tumor.