[Central retinal vein occlusion and opto-ciliary shunts. An angiographic diagnosis]

Opto-ciliary shunts are compensatory bypass channels from the retinal venous system to the choroidal veins in case of long standing central retinal vein occlusion. Indocyanine green angiography with the Scanning Laser Ophtalmoscope may be helpful to differentiate acquired optociliary shunts from retinal or choroidal arteriovenous malformations.

[A new mode of recording retinal activity: multifocal ERG]

Global ERG recordings are only modified in conditions with diffuse or extensive retinal involvement. The use, over the last 6 months, of a new functional testing device: VERIS (visual evoked response imaging system) allows accurate detection and quantification of localized retinal function defects. Our preliminary experience shows that a careful preparation of subjects, standardized testing protocols and a good understanding of the device technology, especially software parameters are mandatory. We report our results on a series of 28 normal volunteers, grouped by age and describe the various graphic presentation of data collected. This technology should allow accurate detection and quantification of retinal functional defects in patients with age related macular degeneration as well as evaluation of visual function in retinitis pigmentosa patients before and after photoreceptor transplantation.

Impact of various red cell concentrate preparation methods on the efficiency of prestorage white cell filtration and on red cells during storage for 42 days

BACKGROUND

White cell (WBC) reduction prior to storage of red cell (RBC) concentrates may reduce the incidence of HLA alloimmunization and may improve the quality of stored RBCs.

STUDY DESIGN AND METHODS

An integrated WBC-reduction filter system was tested after various RBC preparation procedures (from whole blood), and the influence of filtration on RBCs during storage for 42 days was investigated. Four additive system RBC preparation protocols were used. Units prepared from conventional triple blood bags were held for 4 to 6 hours at 22 degrees C, and then the RBCs were separated via a hard spin and filtration, performed immediately (Group 1) or after 18 hours' storage at 4 degrees C (Group 2). Units prepared from a top-and-bottom collection system were held at 22 degrees C for 4 to 6 or 22 to 24 hours; the centrifuged RBCs were filtered immediately after preparation (Groups 3 and 4, respectively, by holding time). WBC reduction and filtration time were analyzed. The impact of WBC filtration on pH, hemolysis rate, hemoglobin content, ATP, potassium glucose, and lactate was investigated weekly during storage for 42 days.

RESULTS

Filtration reduced the mean WBC count by 3 to 4 log10, to 0.19 +/- 0.25 x 10(6), regardless of the RBC preparation method. Mean filtration times differed significantly between the groups and were longest for Group 1. Besides hemolysis and pH values, which were greater in all filtered units, no major differences were found in filtered and unfiltered RBCs during the storage interval.

CONCLUSION

The efficiency of prestorage WBC filtration of RBCs was unaffected by the preparation procedure. However, the filtration time for RBCs freshly prepared in the conventional triple blood bag system without buffy-coat depletion was unacceptable. No major metabolic differences between filtered and unfiltered RBCs during 42 days of storage were found.

Different expression of adhesion molecules on myeloid and B-lymphoid CD34+ progenitors in normal bone marrow

The expression of adhesion molecules was studied on B lymphoid and myeloid CD34+ precursors in normal bone marrow. Bone marrow aspirates were labelled in a double fluorescence procedure with the CD34 monoclonal antibody 43A1 and with antibodies directed against maturation and differentiation antigens and adhesion molecules. Three clusters of CD34+ cells could be distinguished by their light scatter characteristics in flow cytometry. The population with the lowest forward scatter contained B-lymphoid precursors while the two others showed phenotypic characteristics of, respectively, early and late myeloid precursors. Nearly all CD34+ cells in the 3 subpopulations expressed VLA-4, VLA-5, LFA-3 and H-CAM. B-lymphoid progenitors showed a higher density of VLA-4 and VLA-5 than the myeloid progenitors. Myeloid precursors, and particularly the late subset, expressed more HCAM than the B-lymphoid progenitors. The majority of the CD34+ cells also expressed LFA-1 and L-selectin. Higher numbers of positive cells were found in the myeloid subset. The early myeloid subset showed the highest positivity for L-selectin. We conclude that B lymphoid and early and late myeloid CD34+ precursors in normal bone marrow show a different profile of adhesion molecules. These profiles could reflect a higher tendency of the myeloid CD34+ precursors to circulate.

A system for the supply of platelets suspended in a storage medium including buffy-coat-derived platelet concentrates in combination with "split" apheresis platelets

Our objective was to create a system for the supply of platelet concentrates (PCs) based on leukocyte-filtered PCs suspended in a storage medium (PAS-II) including: (1) pooled buffy-coat-derived (BC) PCs and (2) "split" apheresis PCs. The same standards were intended for the two preparations with regard to composition and blood cell counts. In preliminary studies, similar in vitro data were found for leukocyte-filtered and non-filtered reference BC PCs. Slightly inferior in vitro results than for BC PCs restricted the shelf-life of apheresis PCs to 5 days compared to 7 days for BC PCs. With the present platelet supply system in use as a routine service for one year, the experience was very satisfactory, meeting the demands for PCs very efficiently and resulting in a low out-dating rate (5%).

Prestorage leukocyte reduction with in-line filtration of whole blood: evaluation of red cells and plasma storage

OBJECTIVES

Prestorage filtration of blood components appears to be an effective method to reduce leukocyte-induced adverse reactions and other complications. To determine whether it is better to filter whole blood before component separation, we compared the efficiency of in-line filtration of whole blood with that of postseparation filtration.

METHODS

Blood was collected from normal, healthy donors into either regular triple-bag containers or into whole-blood integral-filter container systems. We then compared the in vitro storage values of leukocyte-depleted red blood cell concentrates (RBCC) kept at 4 degrees C, and plasma frozen for 1 year with nonfiltered blood components as control.

RESULTS

All counts of white blood cells after filtration were < 1 x 10(6) per unit. For almost all storage parameters no significant differences were found between leukocyte-reduced RBCC and control units. The plasma fibrinopeptide A values below 30 ng/ml prior to freezing indicate that filtration does not activate the coagulation factors. Furthermore, the filtration did not influence either the biological values or the coagulation factors of plasma units.

CONCLUSIONS

Whole blood filtration prior to component preparation seems to offer a useful alternative technique for obtaining leukocyte-reduced RBCC and plasma.

The absolute number of circulating CD34+ cells predicts the number of hematopoietic stem cells that can be collected by apheresis

We report our single institution's effort to standardize the method of collecting peripheral blood progenitor cells (PBPC) used for autologous transplantation. PBPC were mobilized by different types of chemotherapy followed by G-CSF (24 patients) or G-CSF alone (six patients) in 30 patients with various underlying neoplastic diseases. A median of three aphereses (range: 2-7), using the CS3000 cell separator was performed and a blood volume of 101 was processed. We studied the relationship between the absolute numbers of circulating leukocytes, mononuclear cells and CD34+ cells and the amount of PBPC collected during a single apheresis procedure. CD34+ cells were quantified by leukocyte subset analysis based on flow cytometry. Both CFU-GM and CD34+ cell contents of the apheresis products (69 procedures analyzed) correlated strongly: rho = 0.936, P = 0.0001). Regression analysis showed that the total number of CD34+ cells or CFU-GM content of the apheresis products could be predicted (r = 0.915, P = 0.0001) from the absolute number of CD34+ cells in the blood. A number of 10 circulating CD34+ cells per mm3 blood ensured a minimum of 0.5 x 10(6) CD34+ cells per kg, collected on the same day. Of the 30 patients, 17 received an autologous graft that contained only PBPC in 13. Long-term and complete hematological reconstitution was observed in all patients who had a minimum of 2 x 10(6) CD34+ cells per kg reinfused.

Association of intermediate uveitis with HLA-A28: definition of a new systemic syndrome?

BACKGROUND

Endogenous posterior uveitis (PU) can be associated with systemic diseases, and certain forms have strong association with HLA antigens. Much less is known regarding intermediate uveitis (IU). The purpose of this study was to determine whether IU is associated with the HLA system and whether it can be associated with systemic symptoms.

METHODS

In 179 consecutive patients consulting for uveitis, a detailed history was obtained and a physical examination performed. HLA typing for 71 HLA-A, B, DR and DQ antigens, laboratory tests, and radiography of the chest, sinuses, and sacroiliac joints were systematically performed.

RESULTS

Thirty-two patients (18%) had IU; 51 (28.5%) had PU and constituted our internal control group. Nine of the patients with IU (28%) had the HLA-A28 antigen, compared with 8.1% of a healthy control population and 8.6% of the patients with PU (P < 0.001). An associated disease was found in four patients with IU (12.5%) (none was HLA-A28) and in 45% of the patients with PU (P < 0.01). Some 67% of HLA-A28 patients with IU had arthralgias affecting the knee(s), compared with 17% of non-HLA-A28 patients and 18% of patients with PU (P < 0.05 and P < 0.01 respectively); 55% had gonalgias and hypocomplementemia compared with 9% and 2% respectively (P < 0.01 and P < 0.001).

CONCLUSIONS

IU is significantly associated with HLA-A28; patients having this antigen may represent a subset of the disease characterized by an increased prevalence of arthralgias and hypocomplementemia.

DRB1*0403 protects against IDDM in Caucasians with the high-risk heterozygous DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201 genotype. Belgian Diabetes Registry

The human leukocyte antigen (HLA) class II genotype DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201 has been identified as a marker strongly predisposing to insulin-dependent diabetes mellitus (IDDM) in Caucasian populations. Its frequency in control populations (1-3%) is still, however, 1 order of magnitude higher than the prevalence of IDDM, suggesting that its penetrance can be modified by protective factors. In this study we searched for such a factor in the DRB1 locus by studying DRB1*04 polymorphism in 174 European Caucasian IDDM patients and 73 nondiabetic control subjects, all sharing the HLA-DR3/DR4 phenotype. Significant protection was encoded by the DRB1*0403 allele, which was observed in 5 of 49 control subjects (10%) and none of 171 IDDM patients (0%) with the DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201 genotype (RR = 0.02 [0.01-0.18], P < 0.0005). These data support the concept that protective HLA class II genes can overrule the risk caused by HLA-DQ susceptibility dimers. They also contribute to a possible strategy to screen for nondiabetic individuals with increased genetic risk of developing IDDM.

The SANGUIS Study in Belgium: an overview of methods and results. Safe and good use of blood in surgery

SANGUIS was multicentric European study involving more than 7,000 patients in 43 teaching hospitals during a one year period. The goal of the study was to describe current transfusion practice for elective surgery in adult. The present paper summarizes the data collected on the 1,193 patients enrolled in Belgium. It also introduces the final report of the SANGUIS study in Belgium, which will be published as a special issue of the Acta Chirurgica Belgica.

Bedside transfusion errors. A prospective survey by the Belgium SAnGUIS Group

The true incidence of bedside transfusion errors, i.e. those happening when blood products have left the blood bank, is underestimated because published figures rely on reporting of clinically relevant events or on indirect methods. The SAnGUIS project assessing blood practice in a prospective and randomized fashion for 6 elective surgical procedures gave the opportunity to trace all transfused units and to identify steps at risk during blood delivery in surgery. We considered transfusion of a wrong unit as a major error and poor execution or documentation as a recording error. Over 15 months, 808 patients out of 1,448 were transfused with 3,485 units. A total of 165 errors were found after blood products had left the blood banks. Seven were misidentifications (0.74% of patients, 0.2% of units). Eight other major errors occurred in 4 (0.5%) patients. Major errors occurred during nonemergency situations, in wards or intensive care units. The remaining ('recording') 150 errors consisted of misrecordings (61), mislabellings (6), or failures to document transfusions in the medical records (83). All errors were uneventful except one misidentification which induced a transient, yet unreported, reaction. The 'descending' inquiry method used for this study showed that most errors pass unnoticed and are therefore not reported. Measurement of error rates may constitute an important quality indicator. Retrospective information of this survey to the concerned staff people provided an impetus to take adequate measures to reduce these bedside errors.

5' insulin gene polymorphism confers risk to IDDM independently of HLA class II susceptibility

The polymorphic variable number of tandem repeats in the 5' upstream region of the human insulin gene is a well-known non-human leukocyte antigen locus contributing to genetic susceptibility to IDDM. Controversy exists about the question as to whether INS susceptibility haplotypes are or are not preferentially inherited together with HLA-DR4 haplotypes. We investigated whether genetic interaction between INS and the HLA complex can be better defined using DQ genotypic and phenotypic markers in addition to DR serology. The 5' INS 1/1 genotype was positively associated with IDDM both in non-DR4 subjects (relative risk = 4.3; 95% confidence interval, 1.6-11.5) and DR4 subjects (relative risk = 4.2; 95% confidence interval, 1.9-9.0). Further subdivision of IDDM patients and matched control subjects according to HLA-DQA1 and HLA-DQB1 genotype or phenotype also failed to show any association between 5' INS and HLA class II genes in diabetic patients. The 5' INS and HLA class II polymorphisms therefore provide independent risk markers, which may both contribute to the genetic screening of a high-risk population among nondiabetic individuals.

Chagas' disease: decreased resistance to Trypanosoma cruzi acquired infection in offspring of infected mice

The course of Trypanosoma cruzi infection was studied in an experimental model, using the offspring of mice that were chronically infected with T. cruzi. When infected two months after birth, a higher mortality rate in heavily parasitized mice occurred in these offspring than in controls born to uninfected mothers. The harmful maternal influence reached a maximum when offspring were exposed both to prenatal (placental) and postnatal (lactating) influences. It was a reversible phenomenon that led to a T. cruzi-specific failure of the offspring to control the acute phase of the infection. Such features are suggestive of a maternally-induced impairment of the immune response of the offspring.

Multiple-dose efficacy comparison of the two topical carbonic anhydrase inhibitors sezolamide and MK-927

The multiple-dose twice-daily efficacy of the topical carbonic anhydrase inhibitor MK-927, a racemic compound, was compared with that of its pharmacologically more active S-enantiomer in a four-center, double-masked, randomized, placebo-controlled, parallel study of 1.8% sezolamide hydrochloride (MK-417), 2% MK-927, and placebo, given twice daily to 48 patients with bilateral primary open angle glaucoma or ocular hypertension and morning intraocular pressure greater than 24 mm Hg in both eyes following washout of ocular hypotensive medications. Parallel 10-hour modified diurnal curves were performed before the study and on day 14, with 4-hour curves on days 1 and 4. Both compounds demonstrated significant lowering of intraocular pressure at 8 AM, 12 hours following the evening dose, and through 10 and 6 hours following the 8 AM dose for sezolamide and MK-927, respectively. Morning trough (evening) activity as measured by mean percent change in intraocular pressure from prestudy was -9.2% for sezolamide and -11.1% for MK-927 (-13.5% and -9.6%); peak effect occurred 2 hours after dose administration and was -19.4% and -19.2% for sezolamide and MK-927, respectively. From 2 hours after dose administration, sezolamide consistently demonstrated a slightly greater decrease in intraocular pressure than MK-927; however, these differences were not statistically significant.

[Poisoning of retinal pigment epithelium by deferoxamine. A case report]

A patient undergoing hemodialysis was treated intravenously with desferrioxamine (3 g) for an aluminum encephalopathy. He presented a sudden xanthopsia with visual loss. Fundus examination showed diffuse macular irregular pigmentary disturbances. We discuss current knowledge and possible pathogenesis of these observations published since 1983. Awareness of the side effects of desferrioxamine implies an ophthalmologic follow up similar as chloroquine.

[Candida albicans uveopapillitis. Diagnostic and therapeutic discussion apropos of a case]

Due to the difficulties encountered in the etiologie diagnosis of papillo uveitis along with the increasing occurrence of fungal infections (in paralleled with the number of AIDS affected patients), we found of interest to report a case of exsudative macular chorioretinitis with poor evolution under steroid therapy. In this patient infection by Candida Albicans was suspected and confirmed only after isolation and culture of the fungal from a vitrectomy specimen. A therapeutic apponch using Fluconazole (Triflucan allowed a dramatic improvement of visual acuity within a few months. Thus, vitrectomy appears as a decisive step in the diagnosis of endogenous ocular candidiasis. This diagnosis is even more difficult to suspect in patient without immun deficiency more any extraocular focal infestation.

[Pseudo-exfoliative fibrillopathy in eastern Algeria. Epidemiologic and statistical study]

The systematic examination of 1440 patients of more than 40 years old divided into two groups of 607 hospitalised patients and 833 consultants has revealed the exceptionally high frequency of the pseudo-exfoliative disease in the East of Algeria. In fact this syndrome is find in 25% of the cases. The analysis relates the different epidemiology criteria: age, topography, geographic factors and biomicroscopic characters. The association to the glaucoma of this syndrome forms the subjects of a study which details particularly its frequency, its different clinical forms, the factors of the intraocular pressure and the evolution under treatment. The authors have compared this study to those wHich have been described in literature.

[Clinical applications and critical evaluation of helium-neon laser interferometry]

Exploration of macular function in patients opaque media has been performed routinely with Helium-Neon Laser interferometry for more than 5 years. Our results in patients with cataract, macular diseases, retinal detachment and functional amblyopia are reported. Accurate correlations, overestimations and underestimations are differentiated with special emphasis on overestimations.