Support of cultured hepatocytes by a laminin-rich gel. Evidence for a functionally significant subendothelial matrix in normal rat liver.

The subendothelial space of normal rat liver contains the constituent proteins of a basal lamina, as judged by immunohistochemical study of tissue sections. However, it is unknown whether these proteins constitute a complex with effects on hepatocellular function. We have examined this question, using normal rat hepatocytes cultured on substrata of matrix proteins as a model of the interaction between cells and basal lamina in vivo. In cultures on a type I collagen substratum, albumin secretion decreased progressively after 2 d. By contrast, when cells were cultured on a laminin-rich gel matrix, albumin secretion was stable for at least 3 wk; other functions and ultrastructural morphology were similarly maintained. None of the individual matrix proteins effectively substituted for the gel matrix, suggesting that full support of hepatocellular function requires a complex of matrix proteins. We speculate that a cause of hepatocellular dysfunction in acute inflammation is disruption of this matrix and alteration of its interaction with the hepatocyte plasma membrane.

Sclerosing mesenteritis seen clinically as pancreatic pseudotumor: two cases and a review.

Sclerosing mesenteritis is an uncommon nonneoplastic inflammatory process in the mesentery that is seen as a pseudotumor, usually involving the small bowel mesentery, the mesenteric fat, and less commonly, the mesentery of the large bowel. We report two cases of sclerosing mesenteritis and review the literature on this rare disease. Both patients had pain, profound weight loss, and a mass on computed tomography (CT) scan of the abdomen. The provisional diagnosis was pancreatic neoplasm on the basis of clinical presentation and imaging studies. The diagnosis of sclerosing mesenteritis was established by histologic findings in biopsy material obtained at laparotomy in both cases. Interval histologic studies in one patient who had a high CA 19-9 level, progressive biliary ductal and partial duodenal compression, revealed a transitional histologic pattern from predominant inflammation and fat necrosis to predominant fibrosis. This may explain the varied descriptive terms used in the literature to describe this entity.

Structural and functional reconstruction after resection of aneurysmal bone cyst of the fifth metatarsal: a case study.

We report a case of a primary benign bone tumor (aneurysmal bone cyst [ABC]) involving the distal portion of the fifth metatarsal, identified in an adolescent. The tumor, histologically identified as an ABC with reparative giant cell reaction, became symptomatic. Treatment included resection, followed by reconstruction of the fifth metatarsal using grafts of autologous bone with preservation of function in the metatarsophalangeal joint. The basis for selecting this form of treatment is discussed, as well as the natural history of ABC and giant cell reparative granuloma. Restoration of form and function is illustrated by this case study with a 23-month follow-up.

The angled great toe implant (Swanson design/Weil modification) in the surgical reconstruction of the first metatarsophalangeal joint.

This article deals with implant arthroplasty using the angled great toe implant. Specific terminology is defined. Emphasis is on implant design, criteria for patient selection, and the operative procedure. Postoperative care and complications are briefly touched on.

Plantar fibromatosis: surgical considerations with case histories.

Plantar fibromatosis characteristically is found in the central and medial bands of plantar fascia, although it has been reported in other areas of the foot and, through continued growth and extension, has become adherent to tendons and overlying structures. Clinically, the lesion is somewhat uncommon, usually accompanied with minimal pain and benign in nature. However, it must be distinguished from other possibly malignant lesions that may also localize in the foot. The treatment of choice is surgical extirpation of the mass. Unfortunately, the outer limits of the lesion are difficult to define, and incomplete excision often results in return of the lesion postoperatively. Therefore, a complete fasciectomy of the involved fascia is the procedure of choice in order to reduce markedly the possibility of recurrence of the fibromatosis lesion.

Ankle joint evaluation--an overview of arthroscopic technique.

Arthroscopy is useful in diagnosing and treating ankle pathology. It is comparatively atraumatic, which makes early postoperative ambulation possible and eliminates the problems resulting from casting and immobility. Familiarity with arthroscopic instruments and technique is essential and close attention to details is mandatory to avoid damage to the joint and other complications.

A clinical evaluation of the total first metatarsophalangeal joint prosthesis: the use of footprints in assessing foot contact.

The use of footprints in evaluating surgical results is most significant to the physician. This clinical investigation consisted of patients whose surgical correction of severe hallux valgus included the use of the Swanson-total great toe hinged prosthesis. The resulting failure of weightbearing by the great toe pulp postoperatively were found to be associated with excessive weightbearing by the lesser metatarsal heads, evidenced by discrete keratomas, a relative lesser metatarsalgia, and footprinting analysis. In conclusion, we believe that there is a definite relationship between the lack of weightbearing under the first ray and the instability of the first metatarsophalangeal musculoligamentous structures. This was found to be influenced by metatarsal protusion and first metatarsophalangeal joint range of motion. The possibility also exists that the intrinsic property of silicone played a role in failure of great toe weight-bearing. It is our belief that the Swanson-total is truly and mainly a joint spacer that relieves pain associated with first metatarsophalangeal joint arthrosis. The possibility exists that when using the Swanson-total with a short first metatarsal protrusion it may be necessary to perform shortening osteotomies on the appropriate lesser metatarsals. This redesigning of the metatarsal parabola could restore a normal forefoot weight-bearing pattern and minimize postoperative complications. Further research on this matter is in the planning stages.

Diagnosing osteomyelitis: evaluation and significance of multiple tracer bone imaging.

The use of various radioactive compounds in the diagnosis of osteomyelitis has been the topic of discussion by numerous authors. A great number of bone imaging agents have been experimented with and clinically applied with varying results. It is the intention of this article to detail and compare the use of two such agents: technetium-99m phosphonate, a phosphorus compound radioactively labeled with an isotope of technetium, and gallium citrate 67, a radioactive isotope of gallium. Both of these materials have specific indications and limitations. However, used in the proper setting, either singularly or in conjunction, they give the clinician precise information about pathologic processes. It is the clinician's careful interpretation of both positive and negative test results that enables him to make proper diagnosis and thus institute appropriate therapy.

The use of the Papineau bone-grafting technique in salvage of the infected total joint implant.

The development of osteomyelitis after first metatarsophalangeal total implant-arthroplasty can be a complication encountered by any foot surgeon. The postoperative course is often long with a guarded to poor prognosis. The authors present a salvage procedure for this surgical complication utilizing aggressive surgical debridement followed by an autogenous bone graft. The technique, as described by Papineau, was developed to shorten hospitalization time and reduce deformity. A case presentation is given to illustrate the successful use of this procedure in the treatment of postoperative osteomyelitis of the foot without systemic antibiotics.

Formation of extracellular matrix in normal rat liver: lipocytes as a major source of proteoglycan.

Proteoglycans are a major component of the normal hepatic extracellular matrix and undergo quantitative and qualitative changes in hepatic fibrosis. The cellular sources of proteoglycans are as yet incompletely defined. We examined this question using primary cultures of hepatocytes and lipocytes isolated from normal rat liver. Proteoglycan synthesis was assessed by measuring production of sulfated glycosaminoglycan, the polysaccharide moiety of proteoglycans. The findings indicate that lipocytes produce sixfold more glycosaminoglycan, per cell, than do hepatocytes. Two-thirds of the newly synthesized material is cell- or matrix-associated. Of the individual glycosaminoglycan species produced by lipocytes, dermatan sulfate represents 60% of the total; heparan sulfate and chondroitin sulfate are measurable but relatively minor. In hepatocyte cultures, heparan sulfate accounted for essentially all of the glycosaminoglycan detected. We conclude that lipocytes are an important source of proteoglycan in normal liver and may be the principal source of dermatan sulfate associated with hepatic fibrosis.

Maintenance of differentiated phenotype of cultured rat hepatic lipocytes by basement membrane matrix.

This study examined the role of extracellular matrix in regulating matrix phenotype of hepatic lipocytes, the major source of matrix in liver. Lipocytes (Ito, stellate, or fat-storing cells) were purified from normal rat liver and established in primary culture on either uncoated plastic, plastic coated with individual matrix proteins, or a "complete" gel matrix, a basement membrane-like matrix derived from the Engelbreth-Holm-Swarm (EHS) murine tumor. The ultrastructure of lipocytes cultured on the gel matrix resembled that of cells in normal liver, whereas lipocytes on plastic had dispersed nuclear chromatin and expanded rough endoplasmic reticulum, consistent with active proliferation and secretion. Lipocytes on the gel matrix exhibited no proliferative activity; cells maintained on plastic proliferated and produced type I collagen predominantly. Total collagen secretion by lipocytes on the gel matrix was 29% of that of cells on plastic, and consisted of type III collagen only. This difference extended to proteoglycan production, which was less than 5% of the amount produced by cells in conventional culture on plastic. The effects of the EHS gel were not reproduced by the individual components of the gel (laminin, type IV collagen, and heparan sulfate proteoglycan) or by a type I collagen gel. They were also reversible upon transfer of the cells to conventional culture. In contrast to lipocytes, collagen synthesis by hepatocytes was similar whether cultured on EHS gel or on plastic. These results show that the extracellular matrix can modulate matrix protein production by lipocytes and imply that, in early hepatic inflammation, changes in the hepatic subendothelial matrix may underlie stimulation of lipocyte matrix production and progression of the fibrotic process.

Hepatic disease in patients with the acquired immune deficiency syndrome (AIDS).

The spectrum of liver disease in patients with acquired immune deficiency syndrome (AIDS) and the clinical impact of diagnostic percutaneous liver biopsy in this population were evaluated by a retrospective review of hepatic histology, clinical features and laboratory data in 85 patients (26 biopsies, 59 autopsies). Only 1 (3.8%) biopsy and 9 (15%) postmortem livers were histologically normal. Macrosteatosis and nonspecific portal inflammation were the most common histologic abnormalities. Intrahepatic AIDS-specific opportunistic infections or malignancies were detected in 42% of both biopsy and autopsy groups, with Mycobacterium avium-intracellulare the most frequent pathogen seen. Kaposi's sarcoma, although not detected on biopsy, was the most common postmortem AIDS-related hepatic finding. Intrahepatic lymphoma, cytomegalovirus hepatitis and hepatic mycoses were less frequently observed. In general, hepatic involvement represented part of a previously diagnosed, widely disseminated disease process, and liver biopsy led to new AIDS-specific diagnoses in only two patients. We conclude that while liver biopsy is a useful diagnostic tool in selected patients with AIDS, the information provided by biopsy rarely influences therapy or leads to improved survival.

Early confirmation of stress fractures in joggers.

Four joggers had early confirmation of clinically suspected stress fractures by radionuclide bone scans. The radioactive bone scan was abnormal as early as six weeks prior to the appearance of conventional roentgenographic changes. The stress fractures involved the bones of the lower extremities and included the femur, tibia, and calcaneus. Radioactive bone scanning also correctly identified stress fractures with bilateral involvement and referred pain. In joggers, when a stress fracture is clinically suspected and the conventional radiographs are negative, a radioactive bone scan is indicated for early confirmation and institution of appropriate treatment.