POS0490 SERUM MATRIX METALOPROTINASE 3 AS A MARKER TO DISCRIMINATE SUBCLINICAL DISEASE ACTIVITY FROM ULTRASOUND DEFINED REMISSION IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Rheumatoid arthritis (RA) is a systemic disease which results in chronic inflammation that primarily involves synovial joints resulting in progressive joint destruction [1]. Detection of subclinical disease activity is important as radiographic progression was observed during remission course in some cases [2]. Ultrasound can detect subclinical activity and synovial inflammation, which predict relapse and radiographic progression [3].

Matrix Metaloprotinase 3 (MMP-3) is an enzyme, which is involved in joint destruction in RA patients. MMP-3 was found to correlate with disease activity, joint erosions, radiographic progression, drug responsiveness and disease outcome in patients with active RA [4]. However no data about its role in detection of subclinical activity in patients with clinical remission.

Objectives:

To assess the role of MMP-3 as a marker to discriminate subclinical activity from ultrasound remission in rheumatoid arthritis patients with remission.

Methods:

This study was conducted on 45 RA patients fulfilling remission or low disease activity criteria according to DAS 28 AND 45 healthy controls. Ultrasound evaluation was done for all patients using modified German US7 score. According to US7 score patients were classified into two groups: group with sonographic remission in which GS is 0±1 and the other group with subclinical disease activity with higher GS. Both groups underwent clinical and laboratory evaluation including MMP-3.

Results:

Sonographic remission was achieved in 44% of patients (20 patients). There was no statistically significant difference as regard age, gender, smoking, disease duration, morning stiffness duration, CDAI, treatment and laboratory data apart from hemoglobin level between patients with subclinical disease activity and patients with remission. However, there is statistically significant difference between the two groups as regard joint deformity, extra articular manifestations, DAS 28, SDAI and hemoglobin level.

There was statistically significant difference in serum MMP-3 between RA patients and healthy control group. Serum MMP-3 was higher in RA patients with subclinical activity than patients with sonographic remission but the difference was not statistically significant (figure 1). Serum MMP-3 was positively correlated with ESR and synovitis score.

Figure 1.

Conclusion:

Serum MMP-3 has correlation with US synovitis score. However, serum MMP-3 was not able to differentiate patients with sonographic remission from patients with subclinical disease activity. Ultrasound is still the gold standard for detection of subclinical disease activity.

References:

[1]Ergin, S. (2000). “Romatoid Artrit ve Sjögren Sendromu.” Fiziksel Tip ve Rehabilitasyon, Güneş Kitapevi: 1549-1576.

[2]Ogishima, H., H. Tsuboi, N. Umeda, M. Horikoshi, Y. Kondo, M. Sugihara, T. Suzuki, I. Matsumoto and T. Sumida (2014). “Analysis of subclinical synovitis detected by ultrasonography and low-field magnetic resonance imaging in patients with rheumatoid arthritis.” Modern rheumatology24(1): 60-68.

[3]Filippucci, E., E. Cipolletta, R. M. Mirza, M. Carotti, A. Giovagnoni, F. Salaffi, M. Tardella, A. Di Matteo and M. Di Carlo (2019). “Ultrasound imaging in rheumatoid arthritis.” La radiologia medica124(11): 1087-1100.

[4]Lerner, A., S. Neidhöfer, S. Reuter and T. Matthias (2018). “MMP3 is a reliable marker for disease activity, radiological monitoring, disease outcome predictability, and therapeutic response in rheumatoid arthritis.” Best Practice & Research Clinical Rheumatology32(4): 550-562.

Disclosure of Interests:

None declared

Extraction, characterization and application of malva nut gum in water treatment

In view of green developments in water treatment, plant-based flocculants have become the focus due to their safety, degradation and renewable properties. In addition, cost and energy-saving processes are preferable. In this study, malva nut gum (MNG), a new plant-based flocculant, and its composite with Fe in water treatment using single mode mixing are demonstrated. The result presents a simplified extraction of the MNG process. MNG has a high molecular weight of 2.3 × 10⁵ kDa and a high negative charge of -58.7 mV. From the results, it is a strong anionic flocculant. Moreover, it is observed to have a branch-like surface structure. Therefore, it conforms to the surface of particles well and exhibits good performance in water treatment. In water treatment, the Fe-MNG composite treats water at pH 3.01 and requires a low concentration of Fe and MNG of 0.08 and 0.06 mg/L, respectively, when added to the system. It is concluded that for a single-stage flocculation process, physico-chemical properties such as molecular weight, charge of polymer, surface morphology, pH, concentration of cation and concentration of biopolymeric flocculant affect the flocculating performance.

Common Bile Duct Schwannoma Associated with a Choledochal Cyst

Myelin sheath tumors are neurogenic tumors which include schwannoma, neurofibroma, neurofibromatosis and neurogenic sarcoma. They are most commonly present during middle age and 90% are benign. It has been reported that, they are twice as common in women as in men, but there are few reports of neurogenic tumors in the biliary tract and fewer than 10 cases of schwannoma of the extrabiliary tract.

Characterization of biopolymeric flocculant (pectin) and organic synthetic flocculant (PAM): a comparative study on treatment and optimization in kaolin suspension

Polyacrylamide (PAM), a commonly used organic synthetic flocculant, is known to have high reduction in turbidity treatment. However, PAM is not readily degradable. In this paper, pectin as a biopolymeric flocculant is used. The objectives are (i) to determine the characteristics of both flocculants (ii) to optimize the treatment processes of both flocculants in synthetic turbid waste water. The results obtained indicated that pectin has a lower average molecular weight at 1.63 x 10(5) and PAM at 6.00 x 10(7). However, the thermal degradation results showed that the onset temperature for pectin is at 165.58 degrees C, while the highest onset temperature obtained for PAM is at 235.39 degrees C. The optimum treatment conditions for the biopolymeric flocculant for flocculating activity was at pH 3, cation concentration at 0.55 mM, and pectin concentration at 3 mg/L. In contrast, PAM was at pH 4, cation concentration >0.05 mM and PAM concentration between 13 and 30 mg/L.

Analysis and optimization of flocculation activity and turbidity reduction in kaolin suspension using pectin as a biopolymer flocculant

The performance of pectin in turbidity reduction and the optimum condition were determined using Response Surface Methodology (RSM). The effect of pH, cation's concentration, and pectin's dosage on flocculating activity and turbidity reduction was investigated at three levels and optimized by using Box-Behnken Design (BBD). Coagulation and flocculation process were assessed with a standard jar test procedure with rapid and slow mixing of a kaolin suspension (aluminium silicate), at 150 rpm and 30 rpm, respectively, in which a cation e.g. Al(3+), acts as coagulant, and pectin acts as the flocculant. In this research, all factors exhibited significant effect on flocculating activity and turbidity reduction. The experimental data and model predictions well agreed. From the 3D response surface graph, maximum flocculating activity and turbidity reduction are in the region of pH greater than 3, cation concentration greater than 0.5 mM, and pectin dosage greater than 20 mg/L, using synthetic turbid wastewater within the range. The flocculating activity for pectin and turbidity reduction in wastewater is at 99%.

Unusual Presentation of Peripheral T-Cell Lymphoma

Mature or peripheral T cell lymphomas (PTCL) are uncommon in most parts of the world and account for only 10-15% of all non-Hodgkin's lymphomas (NHLs). They usually occur in middle-aged to elderly patients, 68% presenting with features characterized by a disseminated disease, with systemic symptoms in nearly half of them (45%), bone marrow (BM) involvement in a quarter (25.8%), and extranodal disease in a third (37%). We report for the first time a patient with a lesion on the glans penis, an unusual site.

Treatment of hepatitis C virus genotype 4 with peginterferon alfa-2a: Impact of bilharziasis and fibrosis stage

AIM: To evaluate pegylated interferon alpha2a (PegIFN-α2a) in Egyptian patients with HCV genotype 4, and the impact of pretreatment viral load, co-existent bilharziasis and histological liver changes on response rate.

METHODS: A total of 73 naïve patients (61 with history of bilharziasis) with compensated chronic HCV genotype 4 were enrolled into: group A (38 patients) who received 180 mg PegIFN-alpha2a subcutaneously once weekly for a year and group B (35 patients) received IFN alpha-2a 3 MU 3 times weekly. Ribavirin was added to each regimen at a dose of 1200 mg. Patients were followed for 72 wk and sustained response was assessed.

RESULTS: Significant improvement in both end of treatment response (ETR) (P < 0.002) and sustained response (SR) (P < 0.05) was noted with pegylated interferon, where ETR was achieved in 29 (76.3%) and 14 patients (40%) in both groups respectively, and 25 patients in group A (65.8%) and 9 (25.7%) in group B could retain negative viraemia by the end of follow up period. Sustained virological response (SVR) showed a significant negative correlation with age and positive correlation with pretreatment inflammation in patients receiving PegIFN. Viral clearance after 3 mo of therapy was associated with high incidence of ETR and SR (P < 0.001), but without significant difference between both forms of interferon. Significant improvement in response was achieved in patients with high grade fibrosis (grade 3 and 4) with PegIFN-α2a, where SR was seen in 5 out of 13 patients in group A, but none in group B. There was no significant difference in response between bilharzial and non-bilharzial patients in both groups. In terms of safety and tolerability, neutropenia was the predominant side effect; both drugs were comparable.

CONCLUSION: PegIFN-α2a combined with ribavirin results in improvement in sustained response in HCV genotype 4, irrespective of history of bilharzial infestation.

Lessons to be learned: a case study approach. Paraganglioma of the urinary bladder

Primary paraganglioma arises infrequently in the urinary bladder. We present here the clinicopathological, immunohistochemical and ultrastructural findings in a 23-year-old Saudi female. She was hospitalised because of gross haematuria over the previous seven days. The intravenous urogram revealed a filling defect in the urinary bladder. Cystoscopy disclosed a non-papillary tumour arising from the roof of the bladder neck. Transurethral resection was, accordingly, performed--but marked fluctuation in blood pressure was observed during the procedure. The histopathological findings of trabeculae and small nests of plump oval to spindle cells with a clear to acidophilic cytoplasm, forming an organoid pattern and demonstrating inconspicuous mitotic activity, were diagnostic of paraganglioma of the urinary bladder, the diagnosis was confirmed by means of immunohistochemical and ultrastructural studies. The endocrine markers chromogranin A and neuron-specific enolase were positive in chief cells; sustentacular cells at the periphery of neoplastic cell clusters were positive for S-100 protein. Neurosecretory granules were identified by electron microscopic examination. It is emphasised that, currently, there are no anatomico-pathological criteria to distinguish benign and malignant forms of the disease. Post-surgical recovery was uneventful in this case. Recurrence and metastases, though infrequent, have been reported in the literature; therefore, radiation therapy may be an important adjunct--and long-term follow-up is mandatory.

Primary locally infiltrative gastrointestinal aspergilloma in a non-neutropaenic child

A 21-month-old male child presented with malnutrition and painless abdominal masses. The masses were provisionally diagnosed as being abdominal lymphoma. Pre-operative investigations did not establish any other cause. The diagnosis of primary gastrointestinal aspergilloma was obtained only post-operatively by histopathology and tissue culture. Following surgery, the tumour grew rapidly and massively despite intravenous amphotericin-B, in the recommended doses. The tumour caused recurrent intestinal obstruction which necessitated multiple extensive surgical excisions. The patient finally died due to sepsis and gastrointestinal bleeding. We believe this to be the first description of a primary gastrointestinal aspergilloma with aggressive local infiltration in a non-neutropenic child.

[Acipimox (Olbetam) as a secondary hypolipemic agent in combined hypertriglyceridemia and hyperlipidemia]

32 patients with hypertriglyceridemia, excessive hypertriglyceridemia, and combined hyperlipidemia, were treated with the nicotinic acid derivative acipimox (Olbetam). First line treatment with bezafibrate, or statins in some with combined hyperlipidemia, had failed. In 10 acipimox was discontinued due to side effects or absence of clinical response. The other 22 completed 6 months of treatment with no side effects. Acipimox caused a significant 54% decrease in triglyceride levels, a 23% decrease in total cholesterol, and a 12% increase in HDL-cholesterol. LDL-cholesterol was difficult to calculate because of the high triglyceride levels, so no results are presented. Although acipimox was much better tolerated than nicotinic acid, it also had side effects, but fewer. Acipimox can therefore be used as a second-line drug, mainly in those with combined hyperlipidemia and hypertriglyceridemia.

Helicobacter pylori and intestinal metaplasia with its subtypes in the gastric antrum in a Saudi population

BACKGROUND

There is a close association between intestinal metaplasia (IM) and the development of gastric cancer as well as a relationship between Helicobacter pylori, IM, and gastric cancer. Our aim was to study the frequency and subtypes of IM in a Saudi population with dyspepsia, a population with a low prevalence of gastric cancer.

METHODS

Endoscopic antral biopsy specimens were histologically studied for the presence of IM and H. pylori in consecutive patients who underwent upper gastrointestinal endoscopy for evaluation of dyspepsia. Hematoxylin and eosin and Giemsa stain were used to study IM, inflammation, and H. pylori, whereas Alcian blue, pH 2.5/periodic acid-Schiff and high iron diamine/Alcian blue, pH 2.5, were used to study IM subtypes.

RESULTS

Seven hundred and seventy-eight consecutive patients were recruited in this study, 415 men and 363 women, with a mean age of 43 +/- 17.6 years. Of the 778 patients, IM was identified in 118 (15.2%). The mean ages of patients with IM (48.8 +/- 18.7) and without IM (41.9 +/- 17.4) were statistically significant (P < 0.0001), whereas the patients' sex did not influence the presence of IM. Most had type-I IM (59.3%), whereas 26.3% and 14.4% had types II and III, respectively. The overall rate of infection with H. pylori was 75.4%. There was no difference in the frequency of IM in patients with or without H. pylori (15.5% versus 14.1%; P = 0.65). Of the 118 patients with IM, the 91 patients (77.1%) who also had H. pylori were older (55 +/- 23 years) than those without H. pylori (47 +/- 17 years, P = 0.05).

CONCLUSION

This study has documented mainly that the prevalence of IM and IM subtype III is low in our population. Furthermore, we found no significant relationship between a high rate of H. pylori infection with either IM in general or with IM subtype III in particular, possibly accounting for a low incidence of gastric cancer in the Saudi population.

A logistic regression model to predict nodal malignancy among cases with lymphadenopahty

BACKGROUND

Peripheral lymphadenopathy can be caused by benign and malignant diseases. In this logistic regression model, we attempted to identify the clinical findings predicting high probability of nodal malignancy.

MATERIALS AND METHODS

Two hundred and twenty cases diagnosed by peripheral lymph node biopsy were studied. Of these, 164 had benign lymph node pathology, while the other 56 were malignant. The patientsâ medical charts were reviewed and a logistic regression model used to identify physical signs and simple investigations that will predict nodal malignancy.

RESULTS

Hard lymph node consistency, negative Mantoux test and positive abdominal ultrasound (showing hepatosplenomegaly with or without lymphadenopathy) were found to correlate with a higher probability of nodal malignancy.

CONCLUSION

A logistic regression model is proposed to calculate the probability of lymph node malignancy at different ages and both sexes in relation to lymph node consistency, Mantoux test and abdominal ultrasound results.

Olive oil aspiration pneumonia (lipoid) in children

In the Asir region of south-western Saudi Arabia, nasal instillation of olive oil to infants and children in the recumbent position is practised to relieve nasal congestion. Aspiration of olive oil results in lipoid pneumonia resistant to antimicrobial treatment. A series of 5 children, aged 4-72 months, with olive oil-induced lipoid pneumonia is presented. Clinical presentation included persistent coughing, tachypnoea, recurrent febrile illness and chest infections. The pulmonary radiological picture was mainly right middle lobar and perihilar infiltrates. Bronchial lavage and microscopic examination of the aspirate confirmed the presence of fat globules. The pneumonia resolved on treatment with steroids and physiotherapy in the form of clapping and vibrations. For infants and children in this area who present with persistent pulmonary infiltrates which are not responsive to antimicrobials, the differential diagnosis of not only animal fat (ghee, clarified butter) but also of olive oil lipoid pneumonia must be considered.

Does hypercapillarization influence the branching pattern of terminal villi in the human placenta at high altitude?

This study tests the hypothesis that exposure of the placenta to hypobaric hypoxia at altitude results in an altered branching pattern of the villous tree. Histological material from 20 term placentae delivered at altitudes over 3000 m was compared with matched controls from 500 m. Estimates of the mean star volume of intermediate and terminal villous domains were 1.40 x 10(6) microns3 (s.d. 0.63) in the high altitude group and 1.90 x 10(6) microns3 (s.d. 0.34) in the controls (F = 9.07, P < 0.005). The volume fraction of the villous tree occupied by trophoblastic bridges and syncytial knots was 8.1 per cent (s.d. 3.5) in the high altitude group and 3.2 per cent (s.d. 1.6) in the controls (F = 29.45, P < 0.0001). Previous studies have shown that the majority (80 per cent) of bridges are artefacts caused by the plane of section passing tangentially through the trophoblast layer at points of villous bending or branching. The results are, therefore, consistent with the hypothesis that peripheral villi are shorter, knob-like protrusions at high altitude, clustered more closely together. This modified branching pattern was confirmed by scanning electron microscopy. The change in architecture may be due to enhanced angiogenesis stimulated by the lower partial pressure of oxygen prevailing at high altitude.

Actinomycosis of the vallecula: report of a case and review of the literature

A rare case of actinomycosis presenting primarily as a mass in the vallecula is described. The patient was a healthy, 65-year-old Saudi, lady who was not immunocompromised and had no other primary pathology in the oral cavity. The clinical presentation and management of the case are discussed and the relevant literature reviewed.

Helicobacter pylori infection in gastric cancer: A study of 84 cases from Asir Region

Gastric cancer can be divided into three histologic types: intestinal and diffuse adenocarcinoma, and malignant lymphoma. To determine whether Helicobacter pylori was associated with either cancer type, we reviewed histologic sections from stomachs of 84 patients with the diagnosis of gastric. Of 63 patients with histologic evidence of intestinal adenocarcinoma, 53 (84%) contained H. pylori n noncancerous tissue compared with six (66.7%) of nine patients with diffuse adenocarcinoma (odds ratio = 2.65; Z=1.048; P>0.05) and with eight (66.7%) of 12 patients with non-Hodgkin malignant lymphoma of the stomach (odds ratio = 2.65; Z=0.826; P>0.05). Our findings are compared with reported data from other countries and we are not aware of similar reports from the Kingdom of Saudi Arabia.

Visceral leishmaniasis: II. Histiocyte ultrastructure in bone marrow associated with low level of parasitaemia and mimicking malignant histiocytosis

The ultrastructural features of histiocytes in the bone marrow (BM) were studied in a febrile, splenomegalic and pancytopenic Sudanese patient who was diagnosed by one of us as visceral leishmaniasis (VL) associated with low level of parasitaemia and mimicking malignant histiocytosis (MH). Serial thick (STS) and ultrathin (SUT) sections showed that the BM was hypercellular and markedly infiltrated by large histiocytes with prominent phagocytosis. A thorough examination of various ST and UT section revealed only a single, typical Leishman-Donovan body. At transmission electron microscopy (TEM) level, two principal types of histiocytic cells were identified: Type I, subdivided into two subtypes, were actively phagocytic histiocytes (PH) with large digestive vacuoles and primary lysosomes; type II were nonphagocytic histiocytes (nPH) with primary lysosomes only. The rate of PH to nPH ws 7:2 in plastic STS. The interaction between the PH and ingested cells is described. Both types of cell were morphologically similar to previously described malignant histiocytic cells. However, this study showed a better characterization of PH during VL.

Pattern of primary gastrointestinal tract cancer in the southern province

Two hundred thirty-four cases of primary gastrointestinal tract malignancy were diagnosed at the histopathology laboratory of Asir Central Hospital over a four-year period, from 1987 to 1990. The current study is a retrospective analysis of these cases regarding rank orders, distribution according to nationality, age and sex, primary sites affected and the histopathologic pattern. Eighty-eight percent of our cases were Saudi and 12% were non-Saudi nationals. The mean age of patients was 60 +/- 16 years with a male:female ratio of 2:1. Primary liver cancer was the most common malignancy (29%), followed by gastric cancer (27%), colorectal cancer (21%) and esophageal cancer (13%). Comparison of our findings to those from other provinces of the Kingdom are also included.

Impact of schistosomiasis on urinary bladder cancer in the southern province of Saudi Arabia: review of 60 cases

The histopathologic findings reported in 254 consecutive urinary bladder biopsies were reviewed. Evidence of urinary schistosomiasis was identified in 88 biopsies (35%) and malignant neoplasms were diagnosed in 60 cases (24%). Nine out of 60 (15%) cases of bladder cancer had urinary bladder schistosomiasis and the remaining 51 cases (85%) had no clinical evidence of schistosomiasis. Transitional cell carcinoma was the commonest type of urinary bladder cancer (70%) followed by squamous cell carcinoma (20%) adenocarcinoma (8%) and rhabdomyosarcoma (2%). The mean age of the patients included was 60 +/- 15 years and the male:female ratio was 9:1. Comparison of our findings to those reported from other provinces of Saudi Arabia and from other countries, including those with known high incidence of schistosomiasis, is included.

Peripheral lymphadenopathy as a primary presenting sign: A study of 324 cases from Asir region

Superficial lymph node biopsies received over a four year-period, 1987 to 1990, at the histopathology laboratory of Asir Central Hospital wre reviewed. Total number of patients was 324, all presented with peripheral lymphadenopathy as the primary sign. Two hundred sixty-six patients (82%) were Saudi nationals and 58 patients (18%) were non-Saudi nationals living in Asir region. Granulomatous lymphadenitis was the most common pattern (43%) followed by: nonspecific lymphoid hyperplasia (33%), malignant lymphoma (13%), metastatic nonlymphoid malignant neoplasm (6.6%), and miscellaneous specific lymphadenopathies (4.4%). The distribution patterns of various histopathologic findings according to age, sex, nationality and lymph node location are included.

Idiopathic retroperitoneal and mediastinal fibrosis mimicking connective tissue disease

Combined retroperitoneal and mediastinal fibrosis is a rare manifestation of an idiopathic systemic sclerosing disease. This report describes a multisystem illness that clinically could best be described as polyserositis and progressive renal failure. Pathologically, it was characterized by diffuse infiltration of retroperitoneal and mediastinal tissues with plaquelike fibrofatty connective tissue encasing the kidneys, ureters, adrenal glands, and parietal pericardium. These features are diagnostic of a systemic sclerosing disease. It is important to recognize this unusual disorder to avoid confusion with other systemic connective tissue diseases such as systemic lupus erythematosus.

Binding sites and endocytosis of heparin and polylysine are changed when the two molecules are given as a complex to Chinese hamster ovary cells

This paper characterizes the complex formed in vitro between polylysine and heparin in the presence of heparin excess, and investigates the interaction of this complex with the surface of Chinese hamster ovary cells. It examines the kinetics of surface binding and cellular uptake of the complex and shows that both processes can be distinguished from those of free heparin and free polylysine. The view that these three ligands bind to different surface sites is further supported by the fact that their interaction with cells is influenced differently by cell detachment with trypsin, detachment with EGTA or exposure to acid pH. Membrane transport of the complex is a saturable process suggestive of receptor-mediated endocytosis. It is, however, less effective than would be expected on the basis of the binding kinetics. Only 40% of the complex bound at 0 degrees C is internalized during a 2 h reincubation period at 37 degrees C, suggesting some degree of uncoupling between binding and endocytosis. These data confirm prior results obtained with methotrexate-polylysine conjugates. We had shown that the addition of heparin to a medium containing a methotrexate-polylysine conjugate leads unexpectedly to a marked cellular uptake of drug conjugate, which is capable of killing cells that are otherwise resistant to free methotrexate (Shen, W.-C. and Ryser, H.J.-P. (1981) Proc. Natl. Acad. Sci. USA 78, 7589-7593). The polylysine X heparin complex is therefore of interest as a potential carrier for intracellular drug delivery through endocytosis.

Heparin interaction with cultured cells: possible role of fibronectin in uncoupling surface binding and endocytosis

Cellular uptake of 3H-heparin by cultured Chinese hamster ovary cells does not follow the pattern that would be expected on the basis of binding kinetics. It is essentially non-saturable and its low pinocytotic index is consistent with fluid-phase endocytosis, while surface binding is saturable and suggests the presence of specific receptors. Most of the surface-bound heparin is released into the medium and only minimal amounts are internalized when temperature is shifted from 0 degree to 37 degrees C. This uncoupling of surface binding and endocytosis may be due to the binding of heparin to an external surface macromolecule that is only loosely attached to the plasma membrane, and may therefore escape endocytosis. Fibronectin is a likely candidate to provide that type of binding site. Heparin has been found to bind specifically to a number of mammalian cells (Kjellen et al., 1977; Glimelius et al., 1978; Shanberge et al., 1976; Fabian et al., 1978), but no attempt was made in those studies to distinguish between surface binding and cellular uptake. Heparin is transported into cells when complexed to other macromolecules (Fabian et al., 1978; Shen and Ryser, 1981; Morad et al., 1982) and does then exert some cellular effects (Shen and Ryser, 1981). Despite the wide clinical use of heparin, little is known about its membrane transport and intracellular effects, although endocytosis of other polyanions has been shown to inhibit phago-lysosomal fusion in macrophages (Geisow et al., 1980).(ABSTRACT TRUNCATED AT 250 WORDS)