Preliminary experience with a cuffed ePTFE graft for hemodialysis vascular access

The purpose of this study was to determine graft patency and blood flow rates in recipients of a new cuffed ePTFE graft (Venaflo graft) used for hemodialysis access. A pilot study was conducted with 12 (7 men, 5 women) consecutive patients (age range, 36-76 yr; mean, 65 yr). All patients were recipients of a new cuffed PTFE graft placed for hemodialysis access. Seven were high risk because of a prior history of clotted hemodialysis accesses (1-6; mean, 3.3). Blood flow rates were determined by ultrasound dilution technique at 3 month intervals. One year and 2 year overall graft patency rates were 90.9% and 68.2%, respectively. One graft (high risk, six prior grafts) was lost to thrombosis in the first year; two grafts (one high risk, four prior grafts) were lost to thrombosis in the second year of follow-up. No graft thrombosis resulted from stenosis at the graft-vein anastomosis. Blood flow rates ranged from 550 to 2,110 ml/min (mean, 1,086 ml/min; n = 8) when first measured 3 months after graft placement. Similar flow rates were observed at 12 months (mean, 1,043 ml/min; n = 7) and 24 months (mean, 1,014 ml/min; n = 4) in grafts available for comparison. Dialysis flow rates in excess of 350 ml/min were possible with all patent grafts. A cuffed ePTFE graft provided stable blood flow and satisfactory graft patency during 2 years of follow-up, even in high risk patients with a prior history of vascular access thrombosis.     

Lung dendritic cells are primed by inhaled particulate antigens, and retain MHC class II/antigenic peptide complexes in hilar lymph nodes for a prolonged period of time

Intratracheal (IT) administration of heat-killed Listeria monocytogenes (HKL) results in an influx of macrophage and dendritic cell (DC) precursors into the lung interstitium. Low-density, FcR+, interstitial lung cells isolated from rats instilled 24 hr before with HKL or vehicle alone, were > 90% Mar1+. After culturing with granulocyte-macrophage colony-stimulating factor (GM-CSF) for 3 days, up to 24% of the loosely adherent cells were DC that stimulated allogeneic T-cell proliferation in an mixed lymphocyte reaction (MLR) assay. After only an overnight incubation with GM-CSF, however, the capacity of interstitial Mar1+ cells to stimulate HKL immune T-cell proliferation without exogenous antigen was low. By contrast, when DC were isolated as major histocompatibility complex (MHC) class II+ cells from rat lungs at 1, 3, 7 and 14 days after HKL instillation and cultured overnight with GM-CSF, their antigen presentation capacity without added exogenous antigen was robust, but declined over the 2-week period. Interestingly, hilar lymph node DC maintained their HKL antigen-presenting capacity for up to 2 weeks after instillation of HKL. Following IT administration of PKH-26 labelled HKL, fluorescent or immunolabelled organisms were detected in OX62+ DC in airway epithelium, lung interstitium and hilar lymph nodes in situ and in MHC class II+ DC isolated from these sites. We conclude that newly immigrated Mar1+ lung DC precursors, while efficient in endocytosing particulate antigens, are incapable of eliciting a significant proliferative response from HKL-sensitized T cells. By contrast, MHC class II+ DC isolated from lungs and incubated overnight with GM-CSF induce vigorous antigen-specific T-cell proliferation. Antigen-loaded lung DC in hilar lymph nodes maintain their antigen presentation capacity for up to 2 weeks.     

Accessory cells of the lung. II. Ia+ pulmonary dendritic cells display cell surface antigen heterogeneity

In earlier studies, we had determined that class II (Ia) major histocompatibility complex (MHC) antigen expression in the normal rat lung was limited to dendritic cells and type II alveolar cells. In order to characterize the Ia+ pulmonary dendritic cells of the lung parenchyma, Lewis rat lungs were dissected free of their major airways, enzymatically digested, and serially subjected to density centrifugation on bovine serum albumin, overnight adherence, and immunopanning with a murine anti-rat monoclonal antibody (anti-OX-6) that reacts specifically with class II (Ia) MHC antigens. The purified Ia+ pulmonary cells displayed the morphologic and functional features of dendritic accessory cells, including extended cell processes, absence of nonspecific esterase staining, minimal phagocytosis of latex beads, rapid clustering with T lymphocytes, and co-stimulation of T-cell mitogen responses. Detailed immunophenotyping by cytofluorimetry and immunohistology showed that the purified dendritic cells were Ia (OX-6)+, CD45R (OX-1)+, CD45Rb (OX-22)-, ICAM-1+, and OX-43-. As many as 50% of the cells bound heat-aggregated IgG, while a smaller percentage expressed the CD43 sialophorin antigens (W3/13) expressed by a variety of blood-derived cells, and/or the OX-41 and RMA macrophage antigens. We conclude that Ia+ dendritic cells of lung are heterogeneous with respect to their expression of surface membrane differentiation antigens and may prove to be functionally distinct with respect to their accessory activities.     

Human cytomegalovirus causes productive infection and neuronal injury in differentiating fetal human central nervous system neuroepithelial precursor cells

OBJECTIVES: To study the effect of cell differentiation on the vulnerability of human neural cell types to human cytomegalovirus (HCMV) infection. STUDY DESIGN/METHODS: Primary cultures of human fetal neuroepithelial stem cells and differentiating neuroepithelial precursor cells were infected with HCMV strain AD169. Infectious virus production, apoptosis, and viral-associated cytopathic effects then were examined over a 5-day period. RESULTS: HCMV established productive infection in these cells, generating 10-fold amplification of infectious virus. There was no significant difference in the percentage of apoptotic cells in HCMV-infected versus mock-infected cultures. HCMV antigen and specific cytopathic effects were observed in differentiating astrocytes and neurons, although HCMV antigen was 2-fold more frequent among postmitotic neurons. CONCLUSIONS: Neuroepithelial precursor cells and differentiating astrocytes and neurons are permissive to cytopathic HCMV infection, suggesting that the fetal human central nervous system is vulnerable to HCMV-induced neuronal injury at its earliest stages of development.     

Intramuscular dendritic fibromyxolipoma: Myxoid variant of spindle cell lipoma?

Dendritic fibromyxolipoma (DFML) is an uncommon, recently described, benign soft tissue lesion that shares many clinical and pathological features with myxoid variants of spindle cell lipoma (SCL). As described, DFML is distinguished from SCL by the presence of dendritic cytoplasmic processes, abundant keloidal collagen and a prominent, often plexiform vascular pattern. We describe the first known reported case of an intramuscular DFML that occurred in the right shoulder region of a 73-year-old man. The tumor displayed the typical histopathological features of DFML but also included foci of chondroid metaplasia, a previously unreported finding. This report also discusses the differential diagnosis, particularly distinguishing DFML from SCL and myxoid liposarcoma. In view of the similarities in many clinical and pathological features between SCL and DFML, we speculate that DFML probably represents an unusual variant of myxoid SCL.     

Diagnosis of measles by fluorescent antibody and culture of nasopharyngeal secretions

An indirect fluorescent antibody test (IFA) was evaluated using commercial mouse anti-measles monoclonal antibody and FITC-labeled goat anti-mouse immunoglobulin. For measles isolation, specimens were inoculated into Rhesus monkey kidney (RMK) cells and, when available, CV-1 cells. 381 specimens were tested by IFA and 408 specimens were cultured from patients suspected of having measles. For the 381 specimens tested by both methods, IFA and culture were positive for 31%, culture alone for 14%, IFA alone for 15%, and both negative for 40%. This study indicates that both IFA and culture are required for maximum measles virus detection. Of the positive specimens, 48% were detected either by IFA only (24%) or culture only (24%). IFA was positive in 69% of the culture-positive specimens and therefore, provided rapid diagnosis for many patients.     

Housing type,housing location and mental health

A number of studies have suggested a connection between the type of dwellings which people occupy and their mental health. People who live in flats are usually shown to be more prone to mental illness than those who live in houses. Those who live in high-rise accommodation are shown to be particularly vulnerable. These conclusions were examined by comparing rates on an indicator of psychological distress, in different dwelling types located in good and bad council housing areas. The results suggest that psychological distress is more closely associated with the location of a dwelling than with dwelling type. High-rise flats located on inner-city problem estates are associated with high levels of psychological distress, while low levels are found in similar dwelling types located in the suburbs. These findings are consistent when the effect of age, health, sex and household class are taken into consideration.