Microbes bind complement inhibitor factor H via a common site.

To cause infections microbes need to evade host defense systems, one of these being the evolutionarily old and important arm of innate immunity, the alternative pathway of complement. It can attack all kinds of targets and is tightly controlled in plasma and on host cells by plasma complement regulator factor H (FH). FH binds simultaneously to host cell surface structures such as heparin or glycosaminoglycans via domain 20 and to the main complement opsonin C3b via domain 19. Many pathogenic microbes protect themselves from complement by recruiting host FH. We analyzed how and why different microbes bind FH via domains 19-20 (FH19-20). We used a selection of FH19-20 point mutants to reveal the binding sites of several microbial proteins and whole microbes (Haemophilus influenzae, Bordetella pertussis, Pseudomonas aeruginosa, Streptococcus pneumonia, Candida albicans, Borrelia burgdorferi, and Borrelia hermsii). We show that all studied microbes use the same binding region located on one side of domain 20. Binding of FH to the microbial proteins was inhibited with heparin showing that the common microbial binding site overlaps with the heparin site needed for efficient binding of FH to host cells. Surprisingly, the microbial proteins enhanced binding of FH19-20 to C3b and down-regulation of complement activation. We show that this is caused by formation of a tripartite complex between the microbial protein, FH, and C3b. In this study we reveal that seven microbes representing different phyla utilize a common binding site on the domain 20 of FH for complement evasion. Binding via this site not only mimics the glycosaminoglycans of the host cells, but also enhances function of FH on the microbial surfaces via the novel mechanism of tripartite complex formation. This is a unique example of convergent evolution resulting in enhanced immune evasion of important pathogens via utilization of a "superevasion site."

Renilla luciferase-based quantitation of Potato virus A infection initiated with Agrobacterium infiltration of N. benthamiana leaves.

A quantitation method based on the sensitive detection of Renilla luciferase (Rluc) activity was developed and optimized for Potato virus A (PVA; genus Potyviridae) gene expression. This system is based on infections initiated by Agrobacterium infiltration and subsequent detection of the translation of PVA::Rluc RNA, which is enhanced by viral replication, first within the cells infected initially and later by translation and replication within new cells after spread of the virus. Firefly luciferase (Fluc) was used as an internal control to normalize the Rluc activity. An approximately 10-fold difference in the Rluc/Fluc activity ratio between a movement-deficient and a replication-deficient mutant was observed starting from 48h post Agrobacterium infiltration (h.p.i.). The Rluc activity derived from wild type (wt) PVA increased significantly between 48 and 72h.p.i. and the Rluc/Fluc activity deviated clearly from that of the mutant viruses. Quantitation of the Rluc and Fluc mRNAs by semi-quantitative RT-PCR indicated that increases and decreases in the Renillareniformis luciferase (rluc) mRNA levels coincided with changes in Rluc activity. However, a subtle increase in the mRNA level led to pronounced changes in Rluc activity. PVA CP accumulation was quantitated by enzyme-linked immunosorbent assay. The increase in Rluc activity correlated closely with virus accumulation.

The effect of age and density of the breast on the sensitivity of breast cancer diagnostic by mammography and ultasonography.

PURPOSE: We studied which, age of the patient or density of the breast accounts for the sensitivity of mammography and ultrasonography (US). Furthermore we studied whether the overall impression on the density of the breast or the density in tumour area accounts for the sensitivity of mammography and ultrasonography. MATERIALS AND METHODS: The material consisted of 572 consecutive histologically and 5 cytologically verified breast cancer cases. Mammography and US examinations were performed immediately before breast cancer operations and information on the findings were received from the original patient files and classified as malignant or benign. The density of breast parenchyma to fatty, mixed or dense in total breast and separately in tumour area was defined by a radiologist group from the original mammograms by comparing to model mammograms. The sensitivity (Se) of mammography and US was compared in 3 age groups (26-49, 50-59 and 60-92) and in the different density classes. RESULTS: Sensitivity of mammography increased by age (density-adjusted OR = 0.2, 95%, CI 0.1-0.5) in age group 26-49 compared to age group 60-92) and with fattiness of the breast (age-adjusted OR= 0.4, 95%, CI 0.1-1.0 for dense breast parenchyma in tumour area compared to fatty breast). Sensitivity of US was inversely related to age (density-adjusted OR = 2.3, 95%, CI 1.0-5.2 in age group 26-49 compared to age group 60-92) and directly related with fattiness of breast (age-adjusted OR = 0.5, 95%, CI 0.2-0.9 by dense breast parenchyma in tumour area compared to fatty breast). Density in the tumour area compared to total breast density was related only mariginally better sensitivity both of mammography (0.4 vs. 0.6) and of US (0.5 vs. 0.6). CONCLUSION: Sensitivity of both mammography and sensitivity of US are independently related both to the age of the patient and to the density of the breast. The effect of age is inverse and that of density parallel between mammography and US on sensitivity. The effect of overall breast density was close to the effect of density at the site of the tumour on the sensitivity of both mammography and US.

The visibility of cancer on previous mammograms in retrospective review.

AIM: To study how many tumours were visible in restrospect on mammograms originally reported as normal or benign in patients coming to surgery with proven breast cancer. The effect of making the pre--operative mammogram available was also assessed. MATERIALS AND METHODS: Three hundred and twenty initial mammograms of consecutive new breast cancer cases were analysed by a group of radiologists in the knowledge that all patients were later diagnosed with breast cancer. The films were read twice, first without and then with the later (pre-operative) mammograms available. The parenchymal density in the location of the tumour was classified as fatty, mixed or dense, and the tumours were classified as visible or not visible. The reasons for the invisibility of the tumour in the earlier examination were analysed. RESULTS: Fourteen per cent (45) of cancers were retrospectively visible in earlier mammograms without the pre-operative mammograms having been shown, and 29% (95) when pre-operative mammograms were shown. Breast parenchymal density decreased with age and the visibility of tumours increased with age. When considered simultaneously, the effect of age (over 55 vs under 55) was greater (OR = 2.9) than the effect of density (fatty vs others) (OR = 1.5). The most common reasons for non-detection were that the lesion was overlooked (55%), diagnosed as benign (33%) or was visible only in one projection (26%). Growing density was the most common (37%) feature of those lesions originally overlooked or regarded as benign. CONCLUSIONS: Tumours are commonly visible in retrospect, but few of them exhibit specific signs of cancer, and are recognized only if they grow or otherwise change. It is not possible to differentiate most of them from normal parenchymal densities. Saarenmaa, I. (2001). Clinical Radiology56, 40-43.

Validity of radiological examinations of patients with breast cancer in different age groups in a population based study.

By studying which radiological examinations had been performed before breast cancer operations the aim was to assess, how much benefit ultrasonography (US) and fine or core needle biopsy (FNAB, CNB) gave in addition to mammography, and whether the sensitivity of these examinations varied with the age of the patient. There were 659 consecutive histologically and six cytologically verified breast cancer cases included in the study. Information on mammography, US and FNAB findings were retrieved from the original patient files and classified as malignant or benign. The sensitivity (Se) of these was compared in three age groups (26-49, 50-59 and 60-92). Seventeen (3%) tumours had operations without any radiological examination and 73 (11%) without cytological or histological verification. The sensitivity of mammography (Se=0.92) was statistically significantly higher than the sensitivity of FNAB (Se=0.85, P=0.002) or US (Se=0.86, P=0.003). The sensitivity of mammography increased with age; US sensitivity was slightly higher amongst younger than older patients; the sensitivity of FNAB did not depend on the age of the patient. The sensitivity using a cutoff level of class 5 for mammography was higher (50% typical malignant findings) than for US (45%) or FNAB (30%). Among cases with benign mammographic finding (classes 1-2), the US finding was malignant (classes 3-5) in 4% and FNAB was malignant in 7%. Mammography is a reliable method of breast examination especially for women over 50 years of age. Ultrasonography is beneficial, particularly in younger women, but it is mainly performed as a complementary examination to a mammography and therefore could not be evaluated as an independent examination. FNAB and CNB results were not related to the age of the patient.

Abdominal ultrasonography in myelofibrosis.

The findings at abdominal ultrasonography (US) in 40 patients with myelofibrosis were reviewed, 20 patients being examined at initial diagnosis and 31 at later stages. Splenomegaly was found in 80% at initial diagnosis and in 97% at later stages. The spleen of 2 patients appeared homogeneously hypoechoic and inhomogeneous in one. Focal splenic lesions were seen in 5, and calcifications in 6. Mixed splenic lesions proved to be metastases in one and hyperechoic lesions in another patient were due to extramedullary hematopoiesis. Hepatomegaly was found in 25% at primary diagnosis and in 39% at later stages. Focal hepatic lesions were seen in 7 patients, and proved to be metastases in 3. The focal lesions in 2 of these patients were extramedullary hematopoiesis, which was hypoechoic in one and hyperechoic in the other. Ascites was seen in 4 patients and lymphadenopathy in one. US could not reliably differentiate between extramedullary hematopoiesis and malignancy. Fine-needle biopsy may be performed for definitive diagnosis.

Renal angiomyolipoma. Ultrasonographic, CT, angiographic, and histologic correlation.

The findings at ultrasonography (US), CT, and angiography in 13 patients with renal angiomyolipomas were compared with histologically determined proportions of fatty, myogenic, and vascular components. The angiomyolipoma was composed mainly of fat in 4 cases, half of fat in 2, mainly of myogenic tissue in 4, and was hemorrhagic in 3. US showed high echogenicity in 10 patients, while CT demonstrated attenuation values of fat in 3 tumors with mainly fat tissue but gave non-specific findings in the other cases. The angiographic findings were considered specific for angiomyolipoma in 2 out of 11 cases (18%). Low fat content and hemorrhagic areas caused diagnostic difficulties at both US and CT. The diagnostic algorithm for renal angiomyolipoma is discussed.

The effect of drugs, position of the patient and filling of the stomach on pancreatic sonography.

Using 750 outpatients as our material, the effects of dimethicon , simethicon - pankreatin and lysin-vasopressin, of the position of the patient and of the filling of the stomach with soup on the success of pancreatic ultrasonography were studied. Dimethicon had no, simethicon - pankreatin an almost significant and lysin-vasopressin a highly significant positive effect. Lysin-vasopressin caused several mild adverse reactions. The filling of the stomach with soup combined with erect position was effective in about 3/4 of the cases. Prone position was not usefull.

Arteriographic findings of claudication patients.

The purpose of this work was to study what kind of types of arteriographic changes occur in patients with claudication, whether the patients can be divided into different groups on the basis of the morphology of the arteriographic findings, whether there are any correlations between the arteriographic findings and the patient's age, sex, occupation, bodyweight, smoking habits, diabetes, hypertonia and the arteriosclerosis of the cerebral and coronary arteries. The series consisted of 490 patients subjected to arteriography of the lower extremities because of claudication. There were 399 males and 91 females. The following changes were seen in the arteries of claudication patients: --tortuosity of the distal aorta and the iliac arteries --arteriosclerotic wall changes varying from intimal thickenings to complete occlusions --collaterals --calcific deposits on vascular walls --aneurysms of the distal aorta. The vessels located proximally to the inguinal ligament were tortuous in 63,1% of the patients and extremely tortuous in 11,2%. Single wall changes were seen rarely; 69% of the patients had more than 6 separate plaques. Smooth and flat plaques were also few. 78% of the patients had wall changes of mixed shapes, and 81% had wall changes with irregular contour. A complete occlusion of a vessel was detected in 67%. Symmetric ASO changes were seen in the extremities of 5,3% of the patients. On the basis of the location and extent of the arteriographically diagnosed wall changes, the series was divided into three main groups. The first main group was further divided into three subgroups and the latter two into two subgroups each. Slightly more than half of the patients belonged to the largest group I A, where arteriosclerotic changes were detected in all segments. Gangrenous changes were most frequent in this group. The patients in group III A, which consisted of diffuse changes of the femoro-popliteal region, had the highest (31,8%) frequency of concomitant diabetes and the second highest (30,3%) frequency of concomitant hypertonia. Hypertension was most frequent as a concomitant disease (42,9%) in group I B, which consisted of the patients with aneurysms of the distal aorta. Single arteriosclerotic changes in the femoropopliteal region were few (1,2%). Vascular tortuosity increased with age. The older age groups had more arteriosclerotic changes particularly in the distal aorta, the deep femoral artery, the superficial femoral artery and the popliteal artery.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrasonography of carcinoma of the gallbladder. The images and differential diagnostic problems.

Ultrasonography in the diagnosis of carcinoma of the gallbladder was analysed in a series of 5100 patients, who had a grey-scale sonography of the gallbladder more than 2 years before analysis. Carcinoma has been diagnosed in 12 of the patients. Sonography revealed 8 of the carcinomas. In addition one tumour was diagnosed, which was not considered to originate from the gallbladder. Two patients had carcinoma in situ. The examination of one carcinoma patient was a technical failure. There were 9 false positive findings. Of these 9 patients, one had a metastasis, 5 had a lump of sludge, 3 had a wall thickening caused by chronic cholecystitis and one had an adenomyomatosis.

Transmission media for ultrasonography.

Demonstration of organ structures by ultrasonography is sometimes limited due to the gaseous contents of the gastrointestinal tract. Fluids or semifluids which have a variable acoustic transmission may be used to allow passage of the ultrasound through the obstructing boundaries. These material should not have too low an attenuation relative to soft tissues because then the fixed swept gain curve will cause an effective amplication of the posterior echoes. The materials should also not be too attenuating, thus limiting patient penetration. Various liquid transmission media were tested in their ability to eliminate gas deposits in the gastrointestinal tract. Meat soup was found effective in the stomach and Metamucil was found effective in the colon.

Gray-scale ultrasonography and jaundice.

Forty-nine consecutive jaundiced patients were examined with ultrasonography as the initial imaging method. In 90% could surgical and medical jaundice be differentiated and in 51% the correct specific diagnosis reached.