Functional domains on von Willebrand factor. Recognition of discrete tryptic fragments by monoclonal antibodies that inhibit interaction of von Willebrand factor with platelets and with collagen.

We have identified two functional domains on the von Willebrand factor (VWF) moiety of the Factor VIII-von Willebrand factor complex (FVIII-VWF), one interacting with blood platelets, and one interacting with vessel wall collagens, by means of two monoclonal antibodies directed against the VWF molecule, CLB-RAg 35 and CLB-RAg 201. The monoclonal antibody CLB-RAg 35 inhibited virtually all platelet adherence to artery subendothelium and to purified vessel wall collagen type III, at relatively high wall shear rates. CLB-RAg 35 also inhibited the ristocetin-induced platelet aggregation and the binding of FVIII-VWF to the platelet in the presence of ristocetin but did not affect the binding of FVIII-VWF to collagen. The monoclonal antibody CLB-RAg 201 inhibited the binding of FVIII-VWF to purified vessel wall collagen type I and III and all platelet adherence to collagen type III and the platelet adherence to subendothelium that was mediated by FVIII-VWF in plasma. The two functional domains on FVIII-VWF that were recognized by CLB-RAg 35 and CLB-RAg 201 were identified by means of immunoprecipitation studies of trypsin-digested FVIII-VWF. The domains resided on different polypeptide fragments, with a Mr of 48,000 for the collagen binding domain and a Mr of 116,000 for the platelet binding domain. The 116,000-mol wt fragment consisted of subunits of 52,000/56,000 mol wt and 14,000 mol wt after reduction. The 52,000/56,000-mol wt subunits possessed the epitope for CLB-RAg 35.

Actinomycosis of the abdominal wall after cholecystectomy: transferral theory.

Abdominal actinomycosis is a rare disease caused by Gram-positive anaerobic Actinomyces bacteria. Here, we present a patient with an intrauterine contraceptive device who developed a long lasting and unexplained recurrent, painful abdominal swelling a few months after a laparoscopic cholecystectomy.

The effect of calcium on the secretion of factor VIII-related antigen by cultured human endothelial cells.

Cultured human endothelial cells derived from the umbilical cord vein are able to release factor VIII-related antigen into the culture medium. The experiments described in this paper show the presence of two pathways for the secretion of factor VIII-related antigen from endothelial cells. There is a basal release of this antigen, independent of the presence of extracellular calcium ions. This release can be inhibited by cycloheximide and is therefore directly related to de novo protein synthesis. Besides this basal release, there is an extra release of factor VIII-related antigen that can be stimulated by thrombin, the Ca2+-ionophore A23187 or phorbol myristate acetate. As demonstrated by immunofluorescence, the stimulus-inducible release originates from storage granules in the cells. This stimulus-inducible release is dependent on extracellular Ca2+ but independent of intracellular cAMP.

Respiratory epithelial adenomatoid hamartoma in the nasopharynx.

We present a case report of a female patient with complaints of single-sided nasal obstruction. A polypoid structure was seen in the nasopharynx. Histologic examination showed a respiratory epithelial adenomatoid hamartoma -- a rare, benign lesion. Therapy consisted of complete excision. In line with previous reports, the lesion did not recur during 13 months of follow up. The clinical and pathological features of this abnormality are discussed.

A rapid one-step immunoradiometric assay for factor VIII-procoagulant antigen utilizing monoclonal antibodies.

A two-site immunoradiometric assay for factor VIII-procoagulant antigen (VIIICAg) that relies completely on monoclonal antibodies has been developed. By selecting an appropriate combination of these antibodies, it was possible to develop an assay in which the radiolabelled monoclonal antibody did not inhibit the binding of antigen to the solid-phase monoclonal antibodies. Thus, the entire test could be carried out as a one-step procedure. With this one-step assay, an amount of 0.0025 U VIIICAg/ml plasma could be detected after 4 hr of incubation, whereas 18 hr of incubation resulted in a lower limit of sensitivity of 0.0005 U VIIICAg/ml. The use of a one-step assay provides a significant advantage over the conventional two-step assay by simplifying, shortening and rendering the performance of the assay more convenient.

Phenotypic and genotypic analysis of large-cell lymphomas, formerly classified as true histiocytic lymphoma: identification of an unusual group of tumors.

A group of 12 large-cell lymphomas, seen in the period January 1983 to January 1985 and then tentatively classified as histiocytic sarcomas/true histiocytic lymphomas (i.e. non B-, non T-cell lymphomas, with expression of some histiocytic markers) were restudied phenotypically with a much more extensive range of monoclonal and polyclonal antibodies. They were also genotypically analyzed with respect to rearrangements of genes coding for the immunoglobulin (Ig) heavy and light chains and the gamma and beta chains of the T-cell receptor (TCR). The combined results suggest that these "histiocytic sarcomas" represent a heterogeneous group of large cell lymphomas often with unexpected rearrangements (or lack of rearrangements) of either Ig and TCR genes and phenotypically with coexpression of "histiocytic" and B- or T-cell markers. Such coexpression may be regarded as a warning signal to expect unusual genotype. True histiocytic tumours apparently do exist, but are rare (one case in this study), and their diagnosis is very difficult.

Lack of lymphangiogenesis during breast carcinogenesis.

BACKGROUND: Recent evidence suggests that functional intratumorous lymph vessels may be absent from some human cancers. This could result from either the failure of tumours to induce lymphangiogenesis, or the collapse of lymph vessels, caused by high interstitial tumour pressure. METHODS: To differentiate between these two hypotheses, paraffin wax embedded clinical specimens from normal breast (n = 13), usual ductal hyperplasia (n = 11), ductal carcinoma in situ (n = 21), and invasive breast cancer (n = 40) were compared for lymphatic and blood vessel density by immunohistochemistry with antibodies to the lymphatic endothelial hyaluronan receptor (LYVE-1) and CD31, respectively. RESULTS: Lymph vessel density was lower than blood vessel density in normal breast tissue. Within breast lobuli, lymph vessels were absent. In premalignant lesions blood microvessel density increased, whereas no increase in lymph vessels could be seen intralesionally. In invasive cancers, lymph vessels were absent in all but a few cases, where probably some pre-existing lymph vessels remained, although blood microvessel density was once again increased. CONCLUSION: Unlike angiogenesis, lymphangiogenesis is absent during breast carcinogenesis. This, and not rising interstitial pressure caused by an increase in the size of lesions, explains the absence of intratumorous lymph vessels in invasive breast cancer.

Human papillomavirus in false negative archival cervical smears: implications for screening for cervical cancer.

AIM: To assess the value of detecting human papillomavirus (HPV) DNA in false negative archival cervical smears in population based screening programmes for cervical cancer. METHODS: Cytomorphologically classified false negative archival Pap smears (n = 27) taken from 18 women up to six years before cervical cancer was diagnosed were blindly mixed with 89 smears from hospital patients with a variety of gynaecological complaints and tested for HPV by the polymerase chain reaction (PCR). Corresponding cervical cancer biopsy specimens were also available for HPV analysis. Neither the examining cytopathologist nor the molecular biologist was aware of the study design. RESULTS: HPV DNA was detected in the smears of 16 patients with cervical cancer missed previously by cytology. HPV 16 and 18 were found predominantly in those smears taken up to six years before the diagnosis of cervical cancer. The smears of the two remaining patients were reclassified as inadequate for cytology or contained no suitable DNA for PCR. In 15 patients the same HPV type could be found in the smears and the cervical cancer biopsy specimens. CONCLUSIONS: The results indicate that high risk HPV types can be detected in archival smears classified as false negative on cytology and that cytological screening errors may be reduced if combined with PCR testing for HPV.

Lymph node staging in patients with clinically negative neck examinations by ultrasound and ultrasound-guided aspiration cytology.

To assess the usefulness of ultrasound and ultrasound-guided fine-needle aspiration cytology in detecting occult cervical lymph node metastases, 107 patients with squamous cell carcinoma of the head and neck, who underwent 132 elective neck dissections, had preoperative ultrasound examination. During the assessment of the last 54 patients, who underwent 70 elective neck dissections, ultrasound-guided aspiration cytology was available. Although ultrasound was able to detect lymph node metastases in the majority of patients, the accuracy of this technique never exceeded 70% (93 of 132 procedures). With ultrasound-guided aspiration cytology, accuracy was 89% (62 of 70 procedures). This latter technique seems to be the modality of choice for the assessment of the clinically negative neck. Its use obviates the need for elective neck dissection, done because of the high risk of occult metastasis.

Magnetic resonance imaging vs palpation of cervical lymph node metastasis.

In a series of 100 patients with head and neck carcinoma, the preoperative histopathologic findings of palpation and magnetic resonance imaging were compared with regard to both laterality and lymph node level (I through V). The overall error for palpation in detecting affected sides was 32%. Gadolinium-enhanced magnetic resonance images reliably upgraded 60% of the clinically negative necks, the overall error of magnetic resonance imaging being 16%. However, for both modalities, the sensitivity per level was too low to allow for selective neck dissections in case of only one positive level. These findings show that apart from primary tumor grading, magnetic resonance imaging can improve the preoperative grading of cervical lymph nodes. In selected cases, this may change the treatment plan to a "wait-and-see" policy or a more conservative type of neck dissection.

Therapy-relevant discrepancies between diagnoses of institutional pathologists and experienced hematopathologists in the diagnosis of malignant lymphoma.

We have studied therapy-relevant discrepancies in the diagnoses of institutional pathologists and a panel of 4 experienced hematopathologists in 375 cases from patients with malignant lymphoma. Two hundred and fifty four cases (68%) were contributed by non-panel pathologists and 121 (32%) by individual panel pathologists. Overall, in 24% (91/375) of the cases, therapy-relevant discrepancies were present between institutional pathologists and panel diagnoses. Thirty-four percent (87/254) therapy-relevant discrepancies were present in cases contributed by non-panel pathologists, whereas in only 3% (4/121) discrepancies were found in cases forwarded by individual panel pathologists. The percentages erroneously diagnosed Hodgkin's disease by non-panel pathologists and individual panel pathologists were 8 and 0% respectively and faulty diagnosed Non-Hodgkin lymphomas 5 and 0%, whereas the number of consultation cases, in which the referring pathologist was not certain of his diagnosis, appeared to be 24 and 3% for non-panel and panel pathologists respectively. In addition, in 14% of panel confirmed NHL contributed by non-panel pathologists, therapy-relevant discrepancies in the degree of malignancy grading according to the Working Formulation were present, whereas no discrepancies in malignancy grading were noted between individual panel members and panel diagnoses. Apart from extensive hematopathological experience, a reason for the higher diagnostic accuracy of the panel pathologists could well be the frequency in which the diagnoses were supplemented by immunophenotyping: in 22% of the cases from non-panel pathologists and 63% of the cases from panel pathologists immunophenotyping on frozen sections was carried out.(ABSTRACT TRUNCATED AT 250 WORDS)

Light chain deposition disease without detectable light chains in serum or urine. Report of a case and review of the literature.

A patient presenting with a nephrotic syndrome and chronic renal failure caused by light chain deposition disease (LCDD) without detectable light chains in serum and urine is presented. Only a few patients with LCDD but without detectable light chains in serum and urine have hitherto been reported. The diagnosis was made by light-microscopic and immunofluorescent examination of a percutaneous renal biopsy. The histological differential diagnosis of LCDD includes diabetic glomerulosclerosis, renal amyloidosis and membranoproliferative glomerulonephritis. For the histological diagnosis of LCDD, immunofluorescence using anti-kappa and anti-lambda antisera is essential. Although renal involvement is a constant feature in LCDD, other sites of deposition of light chains have been reported. The absence of detectable light chains in serum or urine is discussed.

Metastatic calciumphosphate deposition in the membranous nasal septum in end-stage renal disease.

Metastatic calciumphosphate depositions are a well known complication of end-stage renal disease. Numerous localisations for metastatic calcification have been described. A patient with a sub-acute swelling of the membranous nasal septum, caused by calciumphosphate depositions is presented. This is the first report of this particular localisation of metastatic calcification in end-stage renal disease.

Atypical leiomyoma of the choana.

Leiomyomas of the nose, nasopharynx and paranasal sinuses are rare. So far only two atypical leiomyomas at these sites have been reported in the English literature. A new case is presented and the literature on the subject is reviewed.

Neonatal Borrelia infections (relapsing fever): report of 5 cases and review of the literature.

Tick borne relapsing fever is an endemic disease in Sengerema district, Mwanza region, Tanzania, East Africa. Five cases of neonatal relapsing fever occurring in this endemic area are described. Two neonates showed signs of septicaemia, clumping of spirochetes (Borrelia index is uncountable) in the thick blood smear and they died the day of admission. Two neonates showed severe spirochetaemia (Borrelia index: 3). The neonate treated with low dose penicillin died, the other neonate, treated with erythromycin, survived. One neonate had only a mild spirochetaemia (Borrelia index is 0.5) and responded well to penicillin treatment. Jaundice was seen in four of the five cases, three of them died. Only twenty cases of neonatal relapsing fever were previously reported. Findings are discussed in comparison with those of former reports on relapsing fever in the literature. Based on the fact that in a relatively short time (1 year), 5 cases of neonatal relapsing fever were diagnosed in an endemic area in East Africa, we conclude that neonatal relapsing fever is probably underdiagnosed.

Detection of factor VIII/coagulant antigen in human liver tissue.

Factor VIII, a high molecular weight glycoprotein complex which has an important role in haemostasis, consists of two immunologically as well as functionally discernible moieties that can be isolated separately. These are factor VIII/von Willebrand factor (FVIII/vWF) which is associated with the factor VIII-related antigen (FVIIIRAg), and the factor VIII/procoagulant activity (FVIII/C) which is associated with the factor VIII/procoagulant antigen (FVIII/CAg). The FVIII/C activity is decreased or absent in patients with haemophilia A (for a review of the structure and function of the factor VIII complex, see refs 1 and 2). Immunological techniques, combined with cell culture, have demonstrated that FVIIIRAg is present in and synthesized by endothelial cells and megakaryocytes. However, the organ and/or cell type responsible for the production of FVIII/C has not been established. Indirect evidence derived from organ transplantation in experimental animals suggests that the liver is the most likely organ for FVIII/C production. Here we have used a monoclonal antibody against FVIII/CAg in combination with a sensitive immunostaining technique to demonstrate the presence of FVIII/CAg in hepatic sinusoidal endothelial cells.

Immunohistological localization of factor VIII in placental endothelial cells.

DNA-recombinant studies have established that factor VIII-mRNA is present in liver and placental tissue. In a previous immunohistological study using monoclonal antibodies we have localized factor VIII in liver sinusoidal endothelial cells. In this paper we demonstrate that also the endothelial cells lining the fetal vessels in human placenta contain factor VIII. Based on the combined results of the present study and a previous study we favour the concept that factor VIII is synthesized in placental endothelial cells.