A novel soluble complement receptor 1 fragment with enhanced therapeutic potential

Human complement receptor 1 (HuCR1) is a pivotal regulator of complement activity, acting on all three complement pathways as a membrane-bound receptor of C3b/C4b, C3/C5 convertase decay accelerator, and cofactor for factor I-mediated cleavage of C3b and C4b. In this study, we sought to identify a minimal soluble fragment of HuCR1, which retains the complement regulatory activity of the wildtype protein. To this end, we generated recombinant, soluble, and truncated versions of HuCR1 and compared their ability to inhibit complement activation in vitro using multiple assays. A soluble form of HuCR1, truncated at amino acid 1392 and designated CSL040, was found to be a more potent inhibitor than all other truncation variants tested. CSL040 retained its affinity to both C3b and C4b as well as its cleavage and decay acceleration activity and was found to be stable under a range of buffer conditions. Pharmacokinetic studies in mice demonstrated that the level of sialylation is a major determinant of CSL040 clearance in vivo. CSL040 also showed an improved pharmacokinetic profile compared with the full extracellular domain of HuCR1. The in vivo effects of CSL040 on acute complement-mediated kidney damage were tested in an attenuated passive antiglomerular basement membrane antibody-induced glomerulonephritis model. In this model, CSL040 at 20 and 60 mg/kg significantly attenuated kidney damage at 24 h, with significant reductions in cellular infiltrates and urine albumin, consistent with protection from kidney damage. CSL040 thus represents a potential therapeutic candidate for the treatment of complement-mediated disorders.

A frameshift variant in the COL5A1 gene in a cat with Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) is a group of heritable connective tissue disorders caused by defective collagen synthesis or incorrect assembly of the collagen triple helical structure. EDS is characterised by joint hypermobility, skin hyperextensibility, abnormal scarring, poor wound healing and tissue friability. Human EDS may be caused by variants in several different genes including COL5A1, which encodes the collagen type V alpha 1 chain. For the present study we investigated a 1.5-year-old, spayed female, domestic shorthair cat with EDS. The affected cat showed multiple recurrent skin tears, hyperextensibility of the skin and joint abnormalities. We obtained whole genome sequencing data from the affected cat and searched for variants in candidate genes known to cause EDS. We detected a heterozygous single base-pair deletion in exon 43 of the COL5A1 gene, namely c.3420delG. The deletion was predicted to result in a frameshift and premature stop codon: p.(Leu1141SerfsTer134). Sanger sequencing confirmed that the variant was present in the affected cat and absent from 103 unaffected cats from different breeds. The variant was also absent from a Burmese cat with EDS. Based on knowledge about the functional impact of COL5A1 variants in other species, COL5A1:c.3420delG represents a compelling candidate causative variant for the observed EDS in the affected cat.

Reconstituted High Density Lipoprotein (rHDL) Modulates Platelet Activity In Vitro and Ex Vivo

A reconstituted high density lipoprotein (rHDL) prepared for clinical use was tested for its influence on platelet activity modulated by various stimuli. In a first series of in vitro experiments, rHDL was added to blood in a concentration series, and platelet rich plasma (PRP) was isolated. Platelets were stimulated with arachidonic acid, collagen, epinephrine or ADP, and platelet aggregation was assessed. rHDL mediated a dose dependent inhibition of the platelet activity. With purified platelets rHDL inhibited the release reaction induced by collagen, but not by thrombin, as measured by CD62P (P-Selectin) expression on the plasma membrane. Ex vivo experiments were performed with PRP from volunteers, previously infused with 25 mg rHDL/kg body weight and 40 mg rHDL/kg body weight, respectively. Platelet activity in PRP was assessed before, and up to 30 h after the end of the rHDL infusion. A transient inhibition of the platelet aggregation induced by arachidonic acid and collagen was observed which was more pronounced in the group receiving 40 mg rHDL/kg body weight. In both groups of experiments, in vitro and ex vivo, the inhibition of the platelet activity was also dependent on the stimulus used.

Dimeric IVIG contains natural anti-Siglec-9 autoantibodies and their anti-idiotypes

BACKGROUND

Intravenous immunoglobulin (IVIG) preparations are increasingly used for the treatment of autoimmune and chronic inflammatory diseases. Naturally occurring autoantibodies against Siglec-9 and Fas are thought to contribute to the anti-inflammatory effects of IVIG via cell death regulation of leukocytes and tissue cells. Dimeric IVIG fractions are suspected to contain idiotypic (Id)-anti-idiotypic complexes of antibodies, which might also include anti-Siglec-9 and anti-Fas autoantibodies.

METHODS

Dimeric IVIG fractions were separated from monomeric IVIG by size-exclusion chromatography and remonomerized by low pH treatment. Binding studies of total, monomeric, and dimeric IVIG were performed using surface plasmon resonance and flow cytometry on primary human neutrophils.

RESULTS

Anti-Siglec-9 and anti-Fas autoantibodies were contained in both monomeric and dimeric IVIG fractions, but anti-Siglec-9 antibodies were highly enriched in dimeric IVIG. The propensity to engage in dimer formation was paratope dependent. IVIG binding to Siglec-9 was specific and sialylation independent. Interestingly, we detected anti-idiotypic antibodies (anti-Ids) against anti-Siglec-9 autoantibodies in dimeric, but not in monomeric fractions of IVIG.

CONCLUSIONS

Our study supports the concept that idiotype-anti-idiotype (Id-anti-Id) interactions contribute to the dimer formation in IVIG preparations. To our knowledge, this is the first description of Id-anti-Id dimers of death receptor-specific antibodies in IVIG. Such Id-anti-Id interactions might determine the activity of immunomodulatory antibodies present both in IVIG and the patient.

Product equivalence study comparing the tolerability, pharmacokinetics, and pharmacodynamics of various human immunoglobulin-G formulations

In this randomized, double-blind, parallel-group study, a commercially available human immunoglobulin-G product, IVIG, was compared with two test formulations: (1) IVIG-N, which is a nanofiltered formulation of IVIG, and (2) IVIG-L, which is a nanofiltered, liquid, ready-for-use IgG formulation containing nicotinamide, L-proline, and L-isoleucine as stabilizers. Three groups of 10 healthy subjects each received a single 0.6 g/kg dose of one of the formulations infused over 3.5 to 6.8 hours, depending on the total volume to be infused. Blood samples were obtained over a 6-week period to assess pharmacokinetics, immunogenicity, and the pharmacodynamic effects on leukocytes and TNF-alpha. A blood sample was taken at 6 months for a viral safety check. Administrations were generally well tolerated with only one reference IVIG infusion stopped prematurely due to headache. The IgG Cmax and AUC over the 6-week blood sampling period from both test formulations satisfied equivalence criteria compared with the reference formulation. In subjects receiving IVIG-L, peak concentrations of the stabilizer nicotinamide ranged from 0.34 to 0.47 mmol/L and of nicotinamide-N-oxide from 0.03 to 0.04 mmol/L, which are below those reported to cause adverse events. During the infusion of IVIG, leukocyte counts initially declined from a baseline of 5.7 +/- 1.1 x 10(9)/L to 3.7 +/- 0.8 x 10(9)/L at 2 to 4 hours and returned to baseline by 24 hours. TNF-alpha levels, reflecting activation of the monocyte-macrophage system by the infused IVIG, rose from a baseline of 13 +/- 4 pg/mL to a peak of 272 +/- 324 pg/mL at 2 to 4 hours and returned to baseline by 24 hours. These patterns were generally similar for the test formulations, with the exception that the increase in TNF-alpha levels was dampened for IVIG-N, although this was not statistically significant. There was no evidence of immunogenicity or viral transmission from any of the formulations. Hence, these three formulations were generally well tolerated, yielded similar systemic exposure to IgG over a 6-week period after administration, and did not give rise to immunogenicity or viral safety concerns.

Reduction of selenite and detoxification of elemental selenium by the phototrophic bacterium Rhodospirillum rubrum

The effect of selenite on growth kinetics, the ability of cultures to reduce selenite, and the mechanism of detoxification of selenium were investigated by using Rhodospirillum rubrum. Anoxic photosynthetic cultures were able to completely reduce as much as 1. 5 mM selenite, whereas in aerobic cultures a 0.5 mM selenite concentration was only reduced to about 0.375 mM. The presence of selenite in the culture medium strongly affected cell division. In the presence of a selenite concentration of 1.5 mM cultures reached final cell densities that were only about 15% of the control final cell density. The cell density remained nearly constant during the stationary phase for all of the selenite concentrations tested, showing that the cells were not severely damaged by the presence of selenite or elemental selenium. Particles containing elemental selenium were observed in the cytoplasm, which led to an increase in the buoyant density of the cells. Interestingly, the change in the buoyant density was reversed after selenite reduction was complete; the buoyant density of the cells returned to the buoyant density of the control cells. This demonstrated that R. rubrum expels elemental selenium across the plasma membrane and the cell wall. Accordingly, electron-dense particles were more numerous in the cells during the reduction phase than after the reduction phase.

Metaplastic lipid-rich carcinoma of the breast

A case of lipid-rich mammary carcinoma identified in a lumpectomy specimen from a 56-year-old female is presented. The tumor showed features of poorly differentiated invasive ductal carcinoma of clear-cell phenotype. Cytoplasmic lucency was mainly accounted for by the accumulation of neutral fat and, to a lesser degree, glycogen. Tinctorial properties included positivity of tumor cells with Sudan III dye and diastase-sensitive periodic acid-Schiff staining. Ultrastructural examination confirmed the presence of abundant cytoplasmic lipid droplets and some glycogen rosettes. On immunohistochemistry, most tumor cells reacted for cytokeratin, vimentin and S-100 protein, and there was focal expression of carcinoembryogenic antigen. A minority of tumor cell nuclei expressed progesterone receptors. As an additional feature, part of the lesion exhibited chondroid metaplasia. Lipid-rich carcinoma of the breast is exceedingly rare and, to our knowledge, no such example harboring metaplastic elements has been described previously.

[Unusual crystalline inclusions in plasmacytoma cells of the testis in primary medullary plasmacytoma]

At the autopsy of a 68 year old man with plasmacytoma of the lambda light chain type we found polygonal interstitial cells with unusual crystalline inclusions, which were not readily identifiable and slightly resembled Leydig cells in conventional microscopy. In electron microscopy these could be identified as plasmacytoma cells, representing a testicular involvement. Comparable cells could be shown in the bone marrow. In immunochemistry we found a polyclonal reaction for lambda light chains suggesting a similar phenomenon as the so-called Russell bodies. As far as we know the literature, this finding in a testicular metastasis has not been described.

BRCA1 mutations in a selected series of breast/ovarian cancer patients

Germline mutations in the BRCA1 gene have been associated with familial breast/ ovarian cancer in large families showing high penetrance of the disease. Little is known, however, about the contribution of BRCA1 mutations to breast/ovarian cancer in small families with few affected members or in isolated early onset cases. Therefore we examined the BRCA1 gene in 63 breast/ovarian cancer patients who either came from small families with as few as one affected first degree relative, or in patients who had no family history but had developed breast cancer under 40 years of age. Using the protein truncation test, we were able to identify three unique BRCA1 germline mutations (4.8%). Two of the probands had only one affected first degree and several second degree relatives and the third had three affected first degree relatives including two sisters who, when tested, were also found to carry the mutation. There was no family history of ovarian cancer in any of the three families.

[Multiple sclerosis: therapy with recombinant beta-1b interferon: initial results with 30 multiple sclerosis patients in northwest Switzerland]

Recombinant interferon beta-1b has been registered with the Swiss health authorities since August 1995. Due to a special arrangement with health insurances it has been possible to prescribe this medication since spring 1995. We report on our experience with the first 30 consecutively treated multiple sclerosis patients. Indication, adverse event profile and clinical response to treatment are described. The most common side effects were local injection site reactions (63%), influenza-like symptoms (50%) and fatigue (33%). As compared to the prestudy period we observed a 49% reduction in the exacerbation rate. Compliance was excellent, possibly due to strict selection and extensive information about possible effects and side effects.

Correlation between the development of extracolonic manifestations in FAP patients and mutations beyond codon 1403 in the APC gene

The APC gene was investigated in 31 unrelated polyposis coli families by SSCP analysis and the protein truncation test. Twenty-three germline mutations were identified which gave rise to a variety of different phenotypes. Some of these mutations have already been described; however we report six previously unpublished mutations. Typical disease symptoms were observed in families who harboured mutations between exon 4 (codon 169) and codon 1393 of exon 15. Mutations beyond codon 1403 were associated with more varied phenotype with respect to the development of extracolonic symptoms. In this report we provide support for the notion that there appears to be a correlation between the location of an APC mutation (beyond codon 1403) and extracolonic manifestations of familial adenomatous polyposis.

Early and severe sensory loss in three adult siblings with hexosaminidase A and B deficiency (Sandhoff disease)

Three siblings in their sixth and seventh decade with hexosaminidase A and B deficiency (adult form of GM2-gangliosidosis, variant O) developed early and severe sensory loss in addition to chronic motor neuron disease and cerebellar ataxia. Prominent mechanoallodynia was a manifesting symptom in two siblings. It is suggested that sensory deficits are due to a central-peripheral dying back axonopathy. The early and dominant sensory disturbances extend the clinical range of GM2-gangliosidosis.

Are papillary adenomas endolymphatic sac tumors?

Papillary adenomas of the temporal bone have been considered as originating from the endolymphatic sac. The radiologic, surgical, and pathologic findings in a patient suffering from von Hippel-Lindau disease with bilateral papillary adenomas of the temporal bone cast some doubt on this site of origin. Radiologically, the center of tumor growth was at the top of the jugular bulb. Intraoperatively, the tumor was found to have reached the lateral wall of the endolymphatic sac, but the lumen was tumor-free. Both ciliated and nonciliated tumor cells were found in the resected tumor, resembling the ultrastructure of normal epithelial lining in the human mastoid. A strong positive immunohistochemical reaction for keratin and negative reactions for vimentin, glial fibrillary acidic protein, and S-100 protein in the tumor tissue of this patient are typical for middle ear mucosa. Therefore, the described papillary adenoma originated from the mucosa of the pneumatic spaces surrounding the jugular bulb, and the theory that the endolymphatic sac is the origin of all papillary-cystic tumors (adenocarcinomas) should be questioned.

Novel germline APC gene mutation in a large familial adenomatous polyposis kindred displaying variable phenotypes

The APC gene is mutated in the germline of people from families where there is a predisposition to develop polyposis coli. Many mutations have been described but the relation between their site and the phenotypic expression of the disease remains unclear. The most commonly seen mutation occurs at codon 1309. Many other mutations have been described towards the 5' end of exon 15 of the APC gene but comparatively few have been seen towards the 3' end. Recent reports have indicated the possibility of a functional boundary with respect to severity and age of onset of disease, which lies towards the 5' end of the gene. This report describes a large family whose affected members present with a very variable phenotype ranging from an early onset and severe form to a comparatively mild later onset one. The mutation that predisposes to disease in this family is at a previously undescribed site that lies towards the 3' end of exon 15 of the APC gene, which results in a stop codon. Interestingly, the stop codon is 63 codons downstream of the mutation and therefore may affect the expression of the disease. The addition of this mutation to the growing list of mutations described in the APC gene may provide some insight into the genotype/phenotype relation of the disease thus contributing to the understanding and significance of mutations at specific sites in the APC gene.

Breast cancer in first degree relatives of 180 female breast cancer patients

The risk of breast cancer and of all malignancies was assessed in first degree relatives of 180 women with breast cancer using a historical cohort study approach. The standardized incidence ratio (SIR) was significantly (p < 0.05) increased for breast cancer in mothers: 1.97 (95% Confidence Interval (CI): 1.27 to 2.91) and in all female first degree relatives: 1.55 (95% CI: 1.08 to 2.15). For breast cancer in sisters it was 1.12 (95% CI: 0.56 to 2.01). For all malignancies the SIR for mothers was 1.12 (95% CI: 0.85 to 1.44), for sisters 1.09 (95% CI: 0.77 to 1.49) and for all female first degree relatives 1.08 (95% CI: 0.89 to 1.32). This study confirms previous investigations showing that breast cancer occurs more frequently in female first degree relatives of women with breast cancer than in the general population.

Comparative in vitro phagocytosis and F-actin polymerization of bovine neonatal neutrophils

Analysis of neonatal neutrophil (PMN) functions should help to reveal factors which could contribute to the impaired host defense system of neonates. We analysed functional parameters of PMN from newborn calves (N-PMN) and adult bovines (A-PMN): cellular volume and F-actin content upon stimulation with complement factors, by cytofluorometry and phagocytosis of E. coli 78:80B with a colorimetric assay. Polymerization of F-actin was rapid in both N- and A-PMN, but reached higher levels in N-PMN. N-PMN are significantly smaller than A-PMN throughout the whole activation time. Percentage of phagocytosing PMN, the rate of phagocytosis, and the rate of killing are similar between A- and N-PMN after opsonization of bacteria with adult serum (AS). Opsonization with newborn serum (NS) reduced all three examined parameters: in A-PMN more (P < 0.001) than in N-PMN (P < 0.05). However, when phagocytosis was compared following age-matched opsonization (N-PMN and NS; A-PMN and AS), N-PMN phagocytosed less (P < 0.001) bacteria per PMN than A-PMN. Additionally, steroidal (dexamethasone) and non-steroidal (phenylbutazone) anti-inflammatory drugs inhibited phagocytosis by N-PMN less than by A-PMN. Higher relative F-actin content of N-PMN can be correlated with the documented functional hyperactivity of bovine N-PMN. However, the exaggerated impairment of phagocytosis in calves observed after age-matched opsonization of bacteria could potentially indicate a specific host defence defect.

Mutational analysis of the first 14 exons of the adenomatous polyposis coli (APC) gene

In the present study, the polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) technique has been applied to the mutation analysis of the adenomatous polyposis coli (APC) gene. We examined the first 14 exons of the APC gene in 46 polyposis coli patients. Five germline mutations were observed, including a single-nucleotide substitution and small (1-4 bp) deletions leading, in 4 cases, to a stop codon. A missense mutation in exon 3 and a 1 bp deletion in exon 4 of the APC gene were observed in patients presenting with the attenuated form of FAP.

[Hereditary p53 mutation in a patient with multiple tumors: significance for genetic counseling]

We describe molecular genetic findings in a patient who initially presented with an intermediate teratoma of the testis and who many years later presented with an oligodendro-astrocytoma. In addition he developed a malignant histiocytoma over the scapula, an adenocarcinoma of the stomach and a late stage adenoma of the sigmoid colon. Due to the development of several neoplasms the possibility of either ataxia telangiectasia or Li-Fraumeni syndrome was considered in differential diagnosis. A molecular genetic investigation revealed that both he and his brother carried a germline p53 tumor suppressor gene mutation at codon 248. From this result we conclude that this family belongs to the Li-Fraumeni syndrome. Once characterized as belonging to the Li-Fraumeni syndrome, the remaining members of the family were typed to determine if they too carried the same mutation. The two children of the index patient were shown not to carry the mutation and are therefore at no increased risk of developing any of the Li-Fraumeni spectrum of malignancies. A molecular genetic investigation into similar families could help to prevent the development of additional malignancies as seen in the index patient, as radiotherapy may interfere with the normal function of the p53 protein and this may in turn help to orchestrate DNA repair after radiation.

[Efficacy of 2 different leukocyte filters for erythrocyte concentrates]

By leukocyte reduction in red blood cell concentrates to < 5 x 10(6) leukocytes per transfused unit, febrile non-hemolytic transfusion reaction as well as alloimmunization and transmission of certain viral diseases (CMV, HTLV-1) can be prevented. Using a Nageotte hemocytometer with a large-volume chamber, the residual leukocyte number after filtration of 40 buffy-coat free red blood cell units with the filters Pall RC100 and Sepacell R500 B1 was determined in a clinical routine setting. Both tested filters underscored the limit (< 5 x 10(6) leukocytes per unit) set by the American Association of Blood Banks. Hemoglobin loss accounted for 8.9 g (Pall RC100) versus 7.7 g (Sepacell R500 B1), which is about 15-18% of the hemoglobin content of a red blood cell concentrate.

Production and characterization of a mouse/human chimeric antibody directed against human neuroblastoma

Hybridoma CE7 produces a murine antibody (gamma 1/kappa) which binds to a 190-kDa cell-surface glycoprotein of human neuroblastoma. Because of its tumor specificity, it has been used routinely in clinical pathology to confirm diagnosis of neuroblastoma. We have isolated the gene segments coding for the variable regions of the immunoglobulin H and L chain of this hybridoma. These V genes were used to construct mouse/human chimeric H and L chain genes (gamma 1/kappa) which were then expressed in SP2/0 cells. A cell-binding inhibition assay showed that the specificity of the chimeric CE7 antibody (chCE7) is identical to that of the original CE7. Radioiodinated chCE7 binds to approximately 43,000 sites per neuroblastoma cell with an affinity of 10(10) M-1. In neuroblastoma-bearing nude mice, biodistribution studies with [125I]chCE7 were performed and tumor accumulations of up to 32% of injected dose/g tissue together with low blood and organ uptake were found.

[Tumor diseases in families of 600 breast cancer patients with special reference to familial adenocarcinomatosis and the Li-Fraumeni-/SBLA syndrome]

In some families breast cancer aggregates as the predominant site-specific neoplasia and in others in association with defined malignancies. In the case of familial adenocarcinomatous (Lynch II-syndrome) it occurs together mainly with colorectal and endometrial carcinoma whereas in the case of the Li-Fraumeni/SBLA-syndrome it belongs to a wider spectrum including sarcoma, brain tumors, lung and laryngeal cancer, leukaemia and adrenocortical carcinoma. The occurrence of these malignancies is reported as they were observed in the families of 600 women suffering from breast cancer.

Venous leakage--a new therapeutical concept

According to our opinion, so-called venous leakage is no venous disease but a result of impaired cavernous tissue. Since in over 90% of all patients with venous leakage also arterial disease was discovered and since ultrastructural degenerative processes in the cavernous bodies were detected, we consider traditional corrective venous surgery as unphysiological and illogical. We suggest arterial revascularization combined with a mechanical penis banding as a new therapeutical concept.

Case report 693: Schneckenbecken dysplasia

Three siblings with SBD from consangineous parents are reported. The prenatal diagnosis of a short-limbed form of dwarfism was made by ultrasonography and the final diagnosis in the index case by radiography, demonstrating a short-limbed, platyspondylic dwarf with a snail-like configuration of the ilium and vertebral bodies, flat on AP and round on lateral view. The histological examination showed a generalized, severe disturbance of cartilage formation with marked hypercellularity of proliferating and resting zones, reduction of intercellular matrix, and shortening of the irregular columns of proliferating cartilage. The ultramicroscopic findings were nonspecific. This is the first report of SBD after the original description, bringing the total to 14 cases in 5 families. The correct radiological diagnosis and the differential diagnosis, in particular thanatophoric dysplasia, are essential for genetic counselling and obstetrical guidance of families affected with this autosomal recessive dysplasia.

[Venous leakage--a new therapeutic concept]

According to our opinion, so-called venous leakage is not a venous disease but a result of impaired cavernous tissue. Since in over 90% of all patients with venous leakage arterial disease has also been discovered, and since in addition ultrastructural degenerative processes have also been detected in the cavernous bodies, we consider the traditional treatment in the form of venous surgery unphysiological and illogical. We suggests arterial revascularization combined with mechanical penis banding as a new therapeutic concept.

Low number of complement C3b/C4b receptors (CR1) on erythrocytes from patients with essential mixed cryoglobulinemia, systemic lupus erythematosus and rheumatoid arthritis: relationship with disease activity, anticardiolipin antibodies, complement activation and therapy

Our aim was to assess whether the amount of complement C3b/C4b receptors (CR1) on erythrocytes shows a correlation to disease activity in various connective tissue diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and essential mixed cryoglobulinemia (EMC). Using an anti-CR1 monoclonal antibody, 26 patients with SLE, 34 with RA and 22 patients with EMC were investigated for erythrocyte CR1 expression. The control group consisted of 30 healthy individuals. The mean number of CR1/erythrocyte in the control group was 568 +/- 197 (range 174-1060), significantly higher than studied (EMC:379 +/- 248; p = 0.0005;SLE 147 +/- 56, p less than 0.0001; RA 298 +/- 177, p less than 0.0001). In patients with RA and in SLE, but not in patients with EMC, the number of CR1 numbers and anticardiolipin antibody (aCl) titers (r2 = 0.493; p = 0.034). A statistically significant correlation between CR1 numbers and CH50 values was found in patients with SLE, while in 3 patients with RA 4 months of therapy with cyclosporine A led to a further 30% reduction in CR1 number. Our conclusions are that (a) the decreased expression of erythrocyte CR1 is apparently a common feature of patients with various connective tissue diseases; (b) several acquired factors such as disease activity, complement activation, aCl and drugs may contribute to the loss of CR1 from erythrocytes; (c) in patients with RA and SLE, but not in patients with EMC, CR1 enumeration on erythrocytes may serve as a variable for clinical monitoring.

[Electron microscopy of the exocrine pancreas in experimental acute hypercalcemia]

Hypercalcemia has been associated with acute pancreatitis clinically and in the experimental animal. We studied the pancreatic ultrastructure in acute experimental hypercalcemia. Anesthetized cats (Pentobarbital, 0.55 mg/kg) received Ca++ (Calcium-Gluconate: 0.6 mmol/kgh; n = 4), K+ (KCl: 1.1 mmol/kgh; n = 4) or NaCl (0.9%; n = 4) locally through retrograde infusion into the splenic artery. Biopsies for electron microscopy (EM) were taken at three hours. Eight cats received intravenous Ca++ (0.6 mmol/kgh, 0.3 mmol/kgh after three hours) or NaCl (0.9%) for 12 hours. Biopsies were collected in two animals in three-hour intervals, and in all animals at twelve hours. After local calcium infusion necrotizing pancreatitis was seen macroscopically in the body of the pancreas. Biopsies for EM showed acinar cell necrosis, hydrops of nuclei and mitochondria and needle-like precipitates in the cytoplasma in the center of calcium perfusion. Biopsies taken from the peripheral region of the macroscopically altered tissue revealed desorganisation of the acinar polarisation and the endoplasmic reticulum, with zymogen granules appearing in the basolateral cell-portion. After intravenous calcium administration no macroscopical changes were seen. In EM acinar cells showed dilatation and proliferation of the golgi apparatus and increased number of condensing vacuoles indicating stimulation. Again, disorganisation of acinar cell polarisation was present. Control animals treated with K+ or NaCl showed normal pancreatic ultrastructure. The morphological changes after calcium infusion indicate direct damage to the acinar cell. Our results suggest that hypercalcemia induced pancreatitis could originate in the acinar cell.

Pathogenesis of osteochondrosis juvenilis Scheuermann

In osteochondrosis juvenilis Scheuermann, foci of various sizes in the cartilaginous end plates of the vertebral bodies display a loosening or complete interruption of the collagen fibers. These findings, together with an alteration and occasional absence of the growth zone, may result in the typical deformation of the vertebral bodies. Electron micrographs of the areas with optically absent collagen fibers reveal collagen fibrils. They are arranged in an irregular pattern. We conclude that a disturbance of collagen or ground substance biosynthesis is of importance in the pathogenesis of juvenile osteochondrosis.

The alternative complement pathway control protein H binds to immune complexes and serves their detection

During solubilization of immune complexes C3b becomes fixed to the immunoglobulin part and serves as a receptor for the alternative complement pathway control protein H. The H-C3b immune complex interaction can be made detectable using 4% polyethyleneglycol to separate free from bound 125I-H. Tetanus toxoid (Te)/anti-Te complexes kept soluble with fresh serum and containing 125 IU of specific antibody bound 18% of 125I-H; when fresh serum was chelated with 10 mM EDTA, 125I-H binding was only 5%. On sucrose density gradients, the H-binding material sedimented in the range of 12 to 30 S. In 36 serum samples from rheumatoid arthritis (RA) patients and in 12 serum samples from patients with systemic lupus erythematosus (SLE), 125I-H binding was significantly elevated to 9.5 +/- 4.7% (mean +/- 1 SD) and 13.3 +/- 5.6%, respectively, while 125I-H binding by 36 normal human sera was 4 +/- 2%. RA samples (17/36, 47%) and SLE samples (9/12, 75%) had H-binding values increased by more than 2 SD above the normal mean. The serum samples were also assessed for conglutinin- and C1q-binding activities; a significant correlation between H and C1q binding was observed (P less than 0.001); there was no correlation between H and conglutinin binding. Although binding to immune complexes through its interaction with C3b, H clearly detects a population of complexes other than conglutinin, thus expanding the possibilities of further characterizing pathological complexes.

Erection and priapism: a new physiopathological concept

For normal erection two mechanisms are essential: the first provides increased arterial inflow, most probably this is obtained due to the activity of the intimal cushions within the arteriae helicinae and within the shunt vessels. The second mechanism uses increased arterial blood flow; this could be obtained due to the activity of the trabecular muscle fibers of the corpora cavernosa. In consequence, we would deal with two different types of priapism: one type--high-flow priapism--occurs at the level of the arteriae helicinae and the intimal cushions and provokes a high-flow situation, and the second type, with blood stasis in the corpora cavernosa, occurs at the level of the trabeculae due to persistent contraction of the smooth muscle fibers. The prognosis of the second type is much less favorable and should be cured by surgery within the first 48 h.

[Revitalization of bovine xenografts used for experimental arterial replacement in dogs (author's transl)]

In 16 mongrel dogs bovine xenografts of 4 to 12 cm of length were used for arterial replacement. The grafts were removed after 30 minutes and up to 13 months for electronmicroscopic examination. The graft was shown to be significantly thrombogenic during the first six weeks after implantation. After 8 to 10 weeks an increasing revitalization of the graft is found starting from the ends of the canine artery. A cover of endothelial cells is formed in the graft lumen. The graft wall is enforced by formation of collagen and elastic fibers originating from capillaries and fibroblasts. Revitalization of the graft is limited to a rim of 2 to 3,5 cm next to the anastomoses with the canine artery. The remaining graft segment shows revitalization only on the outside wall. Degenerative changes take place in the inner layer of the graft with time passing.

[Revitalization of bovine xenograft used for repair of experimental tracheal defects (author's transl)]

In 12 mongrel dogs tracheal defects of different size were covered by bovine xenografts. The grafts were subjected to electronmicroscopic examination 2 to 19 months after implantation. Following the ingrowht of fibroblasts and capillaries a basal membrane is formed on the side of the previous graft lumen. After 4 to 5 months this membrane is covered from the tracheal margins by microvillous cells. After 8 months ciliated epithelia and goblet cells are developed by cell metaplasia. Although the graft becomes revitalized and integrated into the tracheal wall, the layer of ciliated epithelia is interrupted by less differentiated cells. The possible causes for this phenomenon are discussed. Thus bovine xenograft used for the repair of tracheal defects has the following advantages: total revitalization, no shrinkage, less prone to infection and formations of ciliated epithelia.

[Dihydralazine-induced acute hepatitis with IgM deficiency]

Two patients with IgM-deficiency developed acute, recurrent HB3-Ag negative hepatitis with bridging necrosis following ingestion of low daily doses of dihydralazine. The association between the drug and the liver disease appears probable, as recurrence of hepatitis followed each exposure. One patient developed high titers of antimitochondrial antibodies and the other low titers of antibodies against smooth muscles. The relationship between IgM-deficiency and dihydralazine hepatitis is not clear. Investigation of patients with IgM-deficiency for drug hypersensitivity and liver disease may provide additional information.

Generalized gangliosidosis: acid beta-galactosidase deficiency with early onset, rapid mental deterioration and minimal bone dysplasia

This report concerns a 3-month-old girl with rapidly progressive psychomotor retardation, hepatomegaly, vacuolated lymphocytes, minimal bone dysplasia and normal excretion of acid mucopolysaccharides. A deficiency of acid beta-galactosidase was demonstrated in isolated leucocytes and in a liver biopsy. The diagnosis of generalized gangliosidosis due to deficiency of beta-galactosidase was also based on the absence of the enzyme activity from cultured fibroblasts. The diagnosis was confirmed on autopsy at 16 months by typical histology, electron microscopy and biochemistry of the organs. beta-galactosidase deficiency has been demonstrated in various clinical conditions ranging from generalized gangliosidosis with severe mental retardation to clinical pictures resembling Morquio's disease and normal intelligence. The heterogeneity of the clinical manifestations in beta-galactosidase deficiency could be explained by different residual activities of a structurally mutated enzyme towards its various substrates.

Niemann-Pick's disease. Clinical, biochemical and ultrastructural findings in a case of the infantile form

A diagnosis of Niemann-Pick disease type A was made in a 6-month-old boy on the grounds of progressive psychomotor retardation, hepatosplenomegaly, typical foam cells in the bone marrow and a deficiency of sphingomyelinase in a liver biopsy. Typical ultrastructural changes in lysosomes were found in hepatocytes and in Schwann cells. In spite of the absence of gross morphological changes in the axons and in the myelin sheath of the peripheral nerve biopsy, the nerve conduction velocity in the patient was greatly reduced. The ultrastructural aspect of the lysosomal inclusion suggested the storage of a phospholipid. Biochemical analysis of the liver biopsy demonstrated an increased content of total phospholipid of which sphingomyelin made up for more than 60%. The significance of these data are discussed.