Spontaneous osteonecrosis about the knee typically is a disease of the elderly characterized by an acute onset of pain. The exact cause of this condition has long been debated, although a causative ...relationship between meniscal tears and spontaneous osteonecrosis about the knee has been postulated. Seven patients with knee pain, meniscal tears, and chondromalacia without initial evidence of osteonecrosis at magnetic resonance (MR) imaging underwent arthroscopic surgery with meniscal recontouring or repair and cartilage shaving. These patients returned within 2-14 months with recurrent pain in the treated knee. MR imaging then demonstrated abnormalities consistent with osteonecrosis. Osteonecrosis of the femoral condyle or tibial plateau may be a late sequela of meniscal injury in association with chondromalacia and arthroscopic surgery. This diagnosis should be suspected in patients with recurrent knee pain after arthroscopic repair of meniscal tears. The precise relationship of this pattern of osteonecrosis to that previously described as spontaneous requires further investigation.
The ADV-G isolate of Aleutian mink disease parvovirus (ADV) replicates permissively in Crandell feline kidney (CRFK) cells but is nonpathogenic for mink, whereas the highly pathogenic ADV-Utah ...isolate is nonviable in CRFK cells. To assign control of host range in CRFK cells and pathogenicity to specific regions of the ADV genome, we constructed a full-length molecular clone chimeric between ADV-G and ADV-Utah. If either the map unit (MU) 54-65 (clone G/U-5) or MU 65-88 (clone G/U-7) sections were ADV-Utah, viability in CRFK cells was abolished, thus indicating that in vitro host range was controlled by two independent determinants: A in the MU 54-65 segment and B in the MU 65-88 segment. Determinant B could be divided into two subregions, B1 (MU 65-69) and B2 (MU 73-88), neither of which alone could inhibit replication in CRFK cells, an observation suggesting that expression of the B determinant required interaction between noncontiguous sequences. Adult mink of Aleutian genotype inoculated with G/U-8 or G/U-10 developed viremia, antiviral antibody, and histopathological changes characteristic of progressive Aleutian disease. The capsid sequences of G/U-8 and G/U-10 differed from ADV-G at five and four amino acid residues, respectively. Our results suggested that the host range and pathogenicity of ADV are regulated by sequences in the capsid protein gene.
To investigate the dynamic interplay between human immunodeficiency virus type 1 (HIV-l) replication and the extent of immune destruction in HIV-1-infected children, virus burden in lymphoid tissues ...(LN) and peripheral blood was compared with changes in LN architecture and cytokine levels constitutively expressed in LN. In agreement with results of a preliminary study, the plasma HIV-l RNA level correlated with the amount of provirus in LN. However, the level was also associated with a degree of destruction of lymphoid follicular architecture and an alteration of immune cytokine expression. Expression of interleukin (IL)-4 was higher in LN with higher virus replication. Reduction of plasma viremia was associated with an increase in IL-2 mRNA levels in LN. These findings suggest that measurable virus burden in the peripheral blood is not a simple reflection of viral replication in LN but is also influenced by the extent of progressive immune destruction.
CLN6, the gene for a variant late infantile neuronal ceroid lipofuscinosis, has been mapped to chromosome 15q21-23 by homozygosity mapping. At present the family resource consists of 31 families. By ...the analysis of additional polymorphic markers in this resource the critical region has been narrowed down from 12 cM to less than 4 cM. A physical map is being constructed using YAC and PAC clones as a prerequisite to transcript mapping.
Immunoreactive (IR) prolactin was localized immunocytochemically in cell bodies in the mediobasal hypothalamus and in fibers in many regions of the rat brain. The cell bodies were found in the ...arcuate nuclei and the adjacent areas ventral to the ventromedial nuclei. Fiber projections extended rostrally to and/or through the anterior hypothalamus, preoptic area, nucleus accumbens, septum, diagonal bands of Broca, caudate-putamen, frontal cortex and accessory olfactory bulb; laterally to the amygdala, especially the central nucleus and some parts of the medial nucleus; caudally to and/or through the midbrain central gray, reticular formation, parabrachial region, and several portions of the lower brain stem and spinal cord extending to sacral levels. The system appears to be essentially identical to that containing proopiomelanocortin (POMC) and its processed peptides, as shown by double immunocytochemistry. Preabsorption of the antiprolactin antiserum with either prolactin or the 16,000-dalton N-terminus of POMC eliminated immunoreactivity in the brain. Preabsorption with other POMC-derived peptides, including beta-lipotropic hormone, beta-endorphin, met-enkephalin, adrenocorticotrophic hormone (1-24), corticotropin-like intermediate lobe peptide, alpha- and gamma-melanocyte-stimulating hormones and an octapeptide region of the N-terminus of POMC bearing some homology with prolactin, did not eliminate immunoreactivity in the brain. Similarly, preabsorption with growth hormone, luteinizing hormone, follicle-stimulating hormone, motilin or fetuin did not eliminate immunoreactivity in the brain. The antiprolactin antiserum also recognized all cells in the intermediate lobe and a subset of cells in the anterior lobe of the Snell dwarf mouse pituitary. This immunoreactivity was eliminated by preabsorption of the antiserum with prolactin or with the 16,000-dalton N-terminus of POMC. These results suggest that IR prolactin in the brain may be related to the N-terminus of POMC. Additional results based on one- and two-dimensional gel electrophoresis and immunoblotting indicate that the antiprolactin antiserum used in the majority of the immunocytochemical studies recognized a number of proteins.
The skyrocketing cost of medical care in the United States has resulted in multiple efforts in cost containment. The present work offers a rational computer-based cost accounting approach to ...determine the actual use of resources in providing a specific service in a radiation oncology center.
A procedure-level cost accounting system was developed by using recorded information on actual time and effort spent by individual staff members performing various radiation oncology procedures, and analyzing direct and indirect costs related to staffing (labor), facilities and equipment, supplies, etc. Expenditures were classified as direct or indirect and fixed or variable. A relative value unit was generated to allocate specific cost factors to each procedure.
Different costs per procedure were identified according to complexity. Whereas there was no significant difference in the treatment time between low-energy (4 and 6 MV) or high-energy (18 MV) accelerators, there were significantly higher costs identified in the operation of a high-energy linear accelerator, a reflection of initial equipment investment, quality assurance and calibration procedures, maintenance costs, service contract, and replacement parts. Utilization of resources was related to the complexity of the procedures performed and whether the treatments were delivered to inpatients or outpatients. In analyzing time motion for physicians and other staff, it was apparent that a greater effort must be made to train the staff to accurately record all times involved in a given procedure, and it is strongly recommended that each institution perform its own time motion studies to more accurately determine operating costs. Sixty-six percent of our facility's global costs were for labor, 20% for other operating expenses, 10% for space, and 4% for equipment. Significant differences were noted in the cost allocation for professional or technical functions, as labor, space, and equipment costs are higher in the latter. External beam treatment-related procedures accounted for more than 50% of all technical and professional revenues, simulation for 8% to 10%, and other physics/dosimetry procedures for 11% to 14% of revenues. Some discrepancies were identified between the actual cost and level of reimbursement of various procedures. Details are described in the manuscript.
It is imperative to develop an equitable reimbursement system for radiation oncology services, based on cost accounting and other measures that may enhance productivity and reduce the cost per procedure unit, while at the same time preserving the highest quality of service provided to patients.
Recent data have suggested that there may be a relationship between osteoporosis and oral bone loss. Both diseases are major public health problems of enormous magnitude, but their relationship is ...poorly understood. This is due to their complex pathogenesis and the fact that coexisting periodontal disease, loss of the dentition, site-specific variability in anatomy and bone density, as well as aging and many other factors complicate the development and progression of bone loss relative to each. The focus of this article is to review the characteristics of animals that are suited for studies of the relationship of osteoporosis and oral bone loss to better understand their relationship.
The distribution of nerves containing galanin-immunoreactive (GAL-IR) material was compared to the distribution of neurons containing vasoactive intestinal polypeptide (VIP) immunoreactivity in the ...canine gastrointestinal tract. The actions of intra-arterially administered galanin and VIP on motility in the gastric antrum and corpus and the intestines were also studied. All sphincter muscles contained galanin- and VIP-immunoreactive nerve profiles. VIP-immunoreactive nerve profiles were present in all layers of the stomach, small intestine, and colon. GAL-IR nerve somata were common in the submucous plexus of ileum and colon and in the myenteric plexus of the terminal antrum, as were nerve processes in various layers. In the small intestine, galanin inhibited contractile responses to field stimulation of intrinsic nerves and also reduced the contractions after nerve blockade with tetrodotoxin (TTX). VIP often enhanced field-stimulated contractions at low doses but inhibited these and the contractions after TTX at higher doses. In the stomach and colon, both peptides inhibited responses to field stimulation; whether these effects were due to actions on smooth muscle was not tested. The distribution and actions of galanin in gut are consistent with the hypothesis that it acts at smooth muscle sites and possibly at prejunctional sites.
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