Ancillary tests for assessment of the nervous system

This article addresses the minimum data base needed to assist the clinician's diagnostic approach to neurologic diseases. The collection, storage, and processing of cerebrospinal fluid samples are discussed. Additional diagnostic tests are described under selected specific etiologies.

Protective effects of swainsonine on murine survival and bone marrow proliferation during cytotoxic chemotherapy

We have investigated the ability of swainsonine, an indolizidine alkaloid with pleiotropic in vivo effects, to confer protection against the cytotoxic effects of both cell cycle-specific and cell cycle-nonspecific cytotoxic anticancer agents. The intraperitoneal administration of swainsonine decreased the lethality of methotrexate (MTX), fluorouracil (5-FU), cyclophosphamide (CPM), and doxorubicin (DOX) in non-tumor-bearing C57BL/6 mice. The increased survival rate was found to correlate with stimulation of bone marrow cell proliferation, as measured by increases in 1) bone marrow cellularity, 2) in vivo and in vitro colony-forming activity, and 3) engraftment efficiency. These responses were critically dependent on the dose, sequence, and timing of swainsonine administration. If these results are confirmed in humans, swainsonine may offer promise in future intensive chemotherapy programs, allowing increased dosage and/or frequency of administration of cytotoxic agents without increasing toxic effects in bone marrow.

Swainsonine stimulation of the proliferation and colony forming activity of murine bone marrow

Swainsonine, an indolizidine alkaloid, was recently reported to exhibit both antineoplastic and immunomodulatory activities (Humphries, M.J.; Olden, K. Asparagine-linked oligosaccharides and tumor metastasis. Pharmacol. Ther. 44:85-105; 1989). In this study, we show that systemically administered swainsonine promoted the proliferation of murine bone marrow (BM) cells. Animals that received swainsonine intravenously exhibited a significant increase (approximately 5-10 fold) in BM cellularity, engraftment efficiency, and colony forming unit activity using in vitro or in vivo assays. BM cells derived from swainsonine-treated animals or treated with swainsonine in vitro also exhibited a 4-5 fold increase in [3H]-thymidine incorporation, suggesting that a larger fraction of the cells was in the S-phase of the cell cycle. This provides the first evidence that swainsonine, which stimulates the production of cytokines by cells of the immune system, promoted the proliferation of BM progenitor cells. These results suggest that swainsonine could prove valuable in patients undergoing intensive chemoradiotherapy or autologous BM transplantation by decreasing or possibly eliminating leukopenia or myelosuppression often associated with these procedures; it may also be a useful probe to investigate the mechanism of normal hematopoieses.

Vancomycin-induced release of histamine from rat peritoneal mast cells and a rat basophil cell line (RBL-1)

Rapid intravenous administration of the glycopeptide antibiotic, vancomycin, may cause a hypotensive reaction which can usually be prevented by infusing vancomycin in dilute solutions. The release of histamine from circulating cells such as basophils and tissue mast cells has been implicated in hypotensive reactions since the effects can be prevented by antihistamine pretreatment. The direct effects of vancomycin on histamine release were therefore investigated in rat peritoneal mast cells and rat leukemic basophils (RBL-1 cells). Suspension cultures of mast cells or RBL-1 cells were exposed to vancomycin for 30-60 minutes at concentrations comparable to those infused clinically (2.28 or 4.56 mg/ml). Vancomycin induced a time- and dose-dependent release of histamine into the culture media from both cell types. The reference degranulating agent, Compound 48/80 (CP 48/80), was also shown to induce histamine release from mast cells and RBL-1 cells. Mast cells were significantly more sensitive to vancomycin and CP 48/80 than RBL-1 cells and, unlike RBL-1 cells, were responsive to the inhibitory effects of cromolyn sodium on histamine release. Cromolyn sodium did not inhibit vancomycin-induced histamine release in RBL-1 or mast cells. Morphologically, mast cells exposed to either vancomycin or CP 48/80 exhibited dose-related degranulation. On the other hand, treatment-related degranulation effects of either vancomycin or CP 48/80 on RBL-1 cells could not be reliably distinguished from controls by qualitative evaluation. Based upon these findings it is concluded that mast cells may represent a more useful model to evaluate the potential of investigational agents to release histamine and to study mechanisms of histamine release than RBL-1 cells.

Minerals in hair, serum, and urine of healthy and anemic black children

Hair mineral analysis can be used as a reliable screening test for heavy metals, but it is not an established method for defining nutritional and disease states. Wide variation in test results is a major problem in utilizing the technique for clinical purposes. Better reference values are needed, especially for children, as well as information about how hair mineral values correlate with body fluid values. A total of 48 black children were studied. Of these, 20 were normal children, ages 1 to 17; 12 were normal infants, ages 5 weeks to 12 months; 3 were children with iron overload; 7 had iron deficiency anemia; and 6 had thalassemia trait. There were in all 17 boys and 31 girls. The distribution of 15 minerals in hair, serum, and urine samples was determined by energy dispersive X-ray fluorescence. Mineral concentrations from the normal children were compared with concentrations obtained from the children with iron overload, iron deficiency anemia, and thalassemia trait. Statistical analysis revealed no significant differences among any of the groups. Mineral concentrations from the normal infants and children may be useful as reference values. The analysis of hair iron as a valid screening test for body iron status in children is not supported by our data.

The potential importance of swainsonine in therapy for cancers and immunology

Swainsonine, an indolizidine alkaloid, was initially used in biomedical research as a tool to investigate the biosynthesis and function of asparagine-linked 'complex' type oligosaccharide moieties of glycoproteins. Recently, swainsonine has generated interest in its potential use as an anticancer agent with reports that it (i) inhibits tumor growth and metastasis, (ii) augments natural killer (NK) and macrophage-mediated tumor cell killing, and (iii) stimulates bone marrow cell proliferation. The antineoplastic activity of swainsonine can be explained at least in part by augmentation of immune effector mechanisms. The potential application of swainsonine as an anticancer agent is discussed.

Swainsonine modulation of protein kinase C activity in murine peritoneal macrophages

The level of Ca2+, phospholipid-dependent, protein kinase C (PKC) activity in murine peritoneal macrophages treated with swainsonine, an indolizidine alkaloid, has been investigated. The present studies are based on our recent report that murine peritoneal macrophages are activated by swainsonine (Grzegorzewski, K.; Newton, S.A.; Akiyama, S.K.; Sharrow, S.; Olden, K.; White, S.L., Cancer Commun. 1:373-379, 1989). Presently, we have demonstrated that macrophages treated with swainsonine exhibited a substantial increase in PKC activity. The activity was enhanced as much as 4- to 5-fold over that obtained in untreated macrophages and was inhibited by H-7 (1-[5-isoquinoline sulphonyl]-2-methylpiperazine), D-sphingosine, or a monoclonal antibody specific for the active site of PKC. This represents the first report to demonstrate an effect of swainsonine on a second messenger system known to be involved in tumor promotion and macrophage activation. Elevation of PKC activity occurred much more slowly in swainsonine-treated cells than in cells treated with agents known to activate PKC directly, e.g., PMA (4-beta-phorbol-12-beta-myristate-13-gamma-acetate) or gamma-interferon (IFN-gamma). Furthermore the increase in PKC activity was inhibited by alpha-amanitine and cycloheximide, inhibitors of RNA and protein synthesis, respectively. These results suggest that swainsonine enhancement of PKC activity occurred by an indirect and possibly protein-synthesis-dependent mechanism. Whatever its precise mechanism of action, swainsonine provides a potentially important new probe to evaluate PKC mediated events. Selective enhancement of PKC activity may be important not only in elucidating the role of PKC in tumor promotion or macrophage activation but, also, in contributing to development of therapeutic regimens.

Effect of ciprofibrate, bezafibrate, and LY171883 on peroxisomal beta-oxidation in cultured rat, dog, and rhesus monkey hepatocytes

Cultured rat hepatocytes have been used extensively to study the mechanisms of chemically induced peroxisome proliferation. Hepatocytes from nonrodent species have been used on a limited scale to study interspecies differences in the response. Because of their importance in pharmaceutical safety assessment, we have developed a model to study the response of beagle dog and rhesus monkey hepatocytes to peroxisome proliferators. Treatment of the hepatocytes with peroxisome proliferators was begun after 20 hr in culture and continued for 72 hr. Untreated rat, dog, and monkey hepatocytes retained 62, 42, and 43% of their initial (20 hr) peroxisomal beta-oxidation activity throughout 92 hr of culture. Ciprofibrate, bezafibrate, and LY171883 caused a dose-related increase in beta-oxidation in rat hepatocytes to a maximum of 10-, 8-, and 5-fold, respectively. In dog and monkey hepatocytes the increases in beta-oxidation were less than 2-fold. Peroxisome morphology in dog and monkey hepatocytes appeared to be unchanged by the drugs. Morphometric analysis in monkey hepatocytes showed no increase in peroxisome volume fraction in response to the chemicals. Treatment of dog and monkey hepatocytes with dexamethasone and glucagon during the final 24 hr in culture caused a 4- to 6-fold increase in tyrosine aminotransferase activity. This induction is characteristic of the in vivo response. The small increase in beta-oxidation reflects the relative insensitivity of the dog and monkey liver to peroxisome proliferators in vivo rather than a loss of sensitivity during culture. Cultured hepatocytes from beagle dog and rhesus monkey may provide a model for studying the mechanisms underlying the interspecies differences. Such information would help clarify the relevance of rodent data in human risk assessment.

Comparison of in vitro and in vivo models to assess venous irritation of parenteral antibiotics

The venous irritation potential of four parenteral antibiotics, tetracycline hydrochloride (TET), erythromycin lactobionate (ERY), amphotericin B (AMP), and cephaloridine (CEP), was evaluated in an in vivo model using the rabbit ear vein. Lateral ear veins of New Zealand White rabbits were infused for 1 hr with test solutions containing TET (0.25,2.5, or 10 mg/ml), ERY (2.5, 5, or 25 mg/ml), AMP (0.05, 0.1, or 0.5 mg/ml), or CEP (4 or 20 mg/ml). Control rabbits received comparable volumes of 0.9% NaCl or 5% dextrose. Approximately 24 hr postinfusion, the rabbits were evaluated for visually evident changes in the treated ears. Pathologic evaluation of the veins was performed using histologic sections and scanning electron microscopy. TET, ERY, and AMP caused concentration-dependent changes in veins characterized primarily by loss of endothelium with associated inflammation and thrombus formation, consistent with the known clinical irritancy of these antibiotics. CEP, on the other hand, was well tolerated in the rabbit ear vein, paralleling its low irritancy potential in man. Test solutions identical to those used in vivo in rabbits were also evaluated in established in vitro assays for hemolytic potential when mixed with whole blood from monkeys and for damage to L6 muscle cells as determined by loss of creatine phosphokinase. Results of the in vitro test systems paralleled those of the rabbit ear model, with TET, ERY, and AMP exhibiting dose-dependent hemolysis and muscle cell toxicity, while CEP was comparatively nontoxic. Of the three models, the rabbit ear vein had the greatest sensitivity when histopathologic evaluation was employed.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro correlation of ultrastructural morphology and creatine phosphokinase release in L6 skeletal muscle cells after exposure to parenteral antibiotics

Morphologic changes in a rat skeletal muscle cell line (L6) exposed for 1 h to the parenteral antibiotics amphotericin B (AMP), tetracycline-HCl (TET), erythromycin lactobionate (ERY), and cephaloridine (CEP) were characterized by transmission and scanning electron microscopy and compared to cellular release of creatine phosphokinase (CPK). AMP (0.05, 0.1, 0.5 mg/ml) caused a concentration-related swelling of nuclei, endoplasmic reticulum, and mitochondria. Loss of membrane integrity associated with AMP exposure was evident at the middle concentration and extensive at the high concentration, which correlated well with the 43 and 90% depletion of CPK from the muscle cells, respectively. TET (0.25, 1.0, 2.5 mg/ml) caused dilation of endoplasmic reticulum and cytoplasmic blebbing at the low concentration but had no effect on the cytoplasmic membrane or CPK. Cells exposed to the high concentration of TET had extensive damage to the cytoplasmic membrane, and CPK was completely depleted. ERY (2.5, 5.0, 25 mg/ml) caused a pattern of morphologic changes and CPK depletion similar to TET. CEP (4.0, 20, 50 mg/ml) had no effect on membrane integrity or CPK; however, membranous whorls were prominent in the cytoplasm. A good correlation between CPK release and cytoplasmic membrane integrity was evident and the ability of these agents to release CPK from muscle cells in culture correlated with the known irritancy potential of these parenteral antibiotics. Furthermore, CPK depletion seems to be a reliable indicator of muscle cell damage after cytoplasmic membrane perturbation and is therefore an appropriate index of toxicity in this in vitro muscle irritation model.

An assessment of the effects of swainsonine on survival of mice injected with B16-F10 melanoma cells

Systemic administration of swainsonine, an indolizidine alkaloid, inhibits the experimental metastasis of B16-F10 murine melanoma cells. This activity can be attributed primarily to swainsonine-mediated enhancement of host natural killer cell activity. As one next step towards investigating the potential therapeutic utility of this drug, its efficacy in enhancing host survival in the same B16-F10 model system has been assessed. In studies employing intravenously injected tumor cells, pretreatment of mice with swainsonine-containing drinking water provided a reproducible protective effect for the host. This prolongation of survival was substantially enhanced when swainsonine was administered in combination with either of two other immunomodulators, polyinosinic: cytidylic acid (poly-IC) or interleukin-2. In studies in which combinations of these agents were administered after intravenous injection of tumor cells, or after subcutaneous implantation, a greatly reduced effect on host survival was observed. However, when used in combination with cyclophosphamide (to block the effects of suppressor T cells), swainsonine did increase mean survival time. The implications of these results for the use of swainsonine in treatment of metastatic or localized disease, together with its potential mechanism(s) of action, are discussed.

Promoting healthy diets and active lives to hard-to-reach groups: market research study

Continued progress over the next decade in reducing premature morbidity and mortality from chronic disease will require that health communication efforts target a significant proportion of the American public that has not been influenced by the health promotion efforts of the 1980s. Focus groups conducted with members of the hard-to-reach American public showed that while being healthy seemed to be important to participants, and they were generally aware of what to do to stay healthy, they had a different operational definition of health than that used in health promotion programs. Participants seemed to believe that better health behaviors would build their resistance to acute illnesses, that is, keep them healthy, but that chronic diseases, such as cancer and diabetes, were due to fate and heredity and beyond their individual control. The focus group results show that participants had not made the link between chronic disease prevention and the importance of diet, exercise, and weight control. Although most of them seemed to express a genuine interest in "doing better," they were not able to supply more than superficial examples of how such changes might be made. Surprisingly, there were more similarities than differences in participants' attitudes and beliefs, with the similarities cutting across boundaries of race-ethnicity, age, and sex. Interest in changing behaviors was only slightly more pronounced among female rather than male, and older rather than younger, participants. However, there was not much evidence from the participants that they were actively seeking health information or trying to reconcile conflicting knowledge and beliefs.

Experimental approaches for the prevention of hematogenous metastasis

With improvements in surgical procedures and cure rates, the probable course of cancer for the majority of patients is now largely determined by metastasis rather than growth of the primary tumor itself. Thus, metastasis has received increasing attention over the past decade. These studies have led to the identification of several of the molecular events crucial for metastatic dissemination, information which is now being used to design therapeutic strategies to inhibit metastasis formation. Even though the molecular events involved in the dissemination of malignant disease are only partially known, several promising agents are now being tested for their capacity to limit the spread of cancer. A few clinical trials have shown benefit in prolonging survival and disease-free state, particularly when such therapy is employed on an adjuvant basis.

Pulmonary lesions in disseminated visceral coccidiosis of sandhill and whooping cranes

Fifty cranes, consisting of 46 sandhill (Grus canadensis) and four whooping cranes (Grus americana), were studied. Eighteen sandhill cranes and the four whooping cranes were naturally infected with disseminated visceral coccidiosis (DVC). The remaining sandhill cranes were chicks experimentally infected with oocysts of Eimeria reichenowi and/or E. gruis; five chicks served as controls. There were no clinical signs attributed to respiratory infection. Necropsy of naturally infected adult birds revealed nodules in many organs, including the lung, air sacs, trachea and nares. Artificially infected sandhill cranes and the whooping crane chicks that died from DVC had congestion and consolidated areas in the lung with frothy fluid in the airways. Grossly visible nodules were observed from 10 days postinoculation. Granulomatous pneumonia and tracheitis were observed with light microscopy. Lesions were associated with merogonic and gametogonic stages of eimerian coccidia. Granulomas and granulomatous foci contained parasitized large mononuclear cells. Merogonic stages were seen in lymphoid cells by ultrastructural examination. Oocysts were observed in the trachea and bronchial mucosa and admixed with exudate in the airways, indicating that crane eimerians can complete their life cycle at these sites. Of the few eimeriid coccidia that have extraintestinal stages of development in birds and mammals, only the species in cranes complete their life cycle in both the digestive and respiratory tracts.

Swainsonine: a new antineoplastic immunomodulator

Swainsonine, an indolizidine alkaloid with immunomodulatory activity, has been found to be effective in inhibiting metastatic dissemination and growth of primary tumors of both murine and human origins. The unique ability of swainsonine to exhibit antimetastatic, anti-proliferative, and immunomodulatory activity imparts this drug a promising future in cancer therapy.

Swainsonine inhibition of spontaneous metastasis

We have previously shown that swainsonine, administered systemically to C57BL/6 mice, inhibited the pulmonary metastasis of iv injected B16-F10 melanoma cells by a mechanism involving interleukin-2 production and augmentation of natural killer cell activity. From this finding, which uses an "experimental metastasis" model system, we considered: (a) whether swainsonine would be effective in the inhibition of authentic or spontaneous metastasis; (b) whether the drug would also inhibit metastasis formation in organs other than the lungs; and (c) whether the drug would block the metastasis of tumor cells of different histological type or origin. Our data indicated that swainsonine effectively inhibited the spontaneous metastasis of B16-BL6 melanoma (by 88%) and M5076 reticulum sarcoma (by 95%) murine tumor cells to the lung and liver, respectively. In both cases, the antimetastatic activity of the drug increased as a function of the concentration in drinking water up to 3 micrograms/mL. These findings indicate that the antimetastatic activity of swainsonine is not limited to artificial or experimentally induced metastasis nor to a single tumor type or specific organ. The inhibition of metastasis is likely due to a combination of events, which are currently under investigation.

Osteoarthrosis in guinea pigs: histopathologic and scanning electron microscopic features

Spontaneous cartilage degeneration of the femorotibial joint of male Hartley guinea pigs, 61 to 365 days old, was studied by light microscopy (LM) and scanning electron microscopy (SEM) to determine the incidence, age at onset, and to characterize the early changes. Knee joints of 61 day old animals were histologically and ultrastructurally normal. Focal minimal degeneration characterized by cell and proteoglycan loss with surface fibrillation was first observed by LM on the medial tibial plateau (MTP) in two of five 89 day old animals. Mild lesions characterized by focal surface disruption, primarily in the area of medial tibial plateau not covered by the meniscus, were observed in three of five 89 day old animals by SEM. Light microscopic alterations in knee joints of 4, 5, and 6 month old animals consisted of varying degrees of focal chondrocyte death, decreased toluidine blue matrix staining, and surface fibrillation. Small chondrocytic clones were first observed in medial tibial cartilage of 6 month old animals with moderate focal degeneration. Ultrastructurally, 4, 5, and 6 month old animals generally had moderate to severe fibrillation involving primarily the area of the medial tibial plateau not covered by the meniscus. Tibial osteophyte formation, mild synovial hyperplasia, medial femoral and meniscal cartilage degeneration, were first seen by LM in 9 month old animals. Lesions in 1 year old animals were similar, but more severe and included subchondral sclerosis of medial tibial and femoral bone. Bilateral fibrillation of greater than 50% of the medial tibial articular surface was observed in all 1 year old animals by SEM.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of macrophage tumoricidal activity, major histocompatibility complex class II antigen (Iak) expression, and interleukin-1 production by swainsonine

Previous studies in our laboratory have shown that the reported antitumor activity of systemically administered swainsonine, an indolizidine alkaloid, is due at least in part to immune modulation involving effector cells (Humphries, M.J.; Matsumoto, K; White, S.L.; Olden, K. Cancer Res. 48:1410-1415; 1988 and White, S. L.; Schweitzer, K.; Humphries, M.J.; Olden, K. Biochem. Biophys. Res. Commun. 150:615-625; 1988). In this report, studies are presented to show that swainsonine was effective in activating peritoneal macrophages to cytotoxicity against tumor cells. Stimulation of tumoricidal activity of macrophages was associated with increased secretion of interleukin-1 (IL-1) and expression of the Iak major histocompatibility complex (MHC) antigen on the cell surface. The 3-fold stimulation of cytotoxicity observed in these in vivo studies was comparable to that obtained with Corynebacterium parvum, a commonly used in vivo activating agent. The in vitro incubation of thioglycollate-elicited peritoneal macrophages with swainsonine consistently resulted in levels of activation (6- to 8-fold) comparable to that obtained by treatment with known in vitro macrophage activating agents such as lipopolysaccharide (LPS) or recombinant gamma-interferon (rIFN-gamma). The stimulation observed by using swainsonine in combination with LPS was additive, suggesting different mechanisms of action. These studies have important implications not only for treatment of cancer, infectious diseases, and immune suppressive disorders, but also for elucidation of the mechanism of macrophage activation.

Augmentation of murine natural killer cell activity by swainsonine, a new antimetastatic immunomodulator

Swainsonine, an indolizidine alkaloid, has been found to inhibit the experimental metastasis of B16-F10 melanoma cells when administered systemically to syngeneic C57BL/6 mice. The inhibition was both potent and dose dependent with greater than or equal to 80% reduction in pulmonary colonization being observed after only 24-h exposure to 3 micrograms/ml of swainsonine in drinking water. In contrast, the inhibitory activity of swainsonine was completely abrogated when assays were performed in mice depleted of their natural killer (NK) cell activity either experimentally (anti-asialo-GM1 antibody- or cyclophosphamide-treated C57BL/6 mice) or as a result of genetic mutation (homozygous C57BL/6bg/bg beige mice). Swainsonine elicited a 32.0% increase in spleen cell number 2 days after administration and induced a concomitant 2- to 3-fold increase in splenic NK cell activity. These results indicate (a) an absolute requirement for a functional NK cell population in order for swainsonine to exert its inhibitory effects on experimental metastasis, and (b) that the antimetastatic activity of swainsonine is mediated primarily through the ability of the drug to augment NK cell reactivity. On the basis of these findings, swainsonine can be classified as a new immunomodulator that has the ability, at least in a prophylactic setting, to block tumor metastasis.

Measuring hospital competition

This paper appraises the use of the Herfindahl market share index as an exogenous competition variable in empirical studies of the hospital sector. An analysis of cross-sectional Florida data shows that this index itself is significantly influenced by the demand and supply factors commonly included in econometric models of hospital performance. The analysis then illustrates that biased inferences about the effects of market competition on the costs of hospital care may result unless the values of the Herfindahl Index are treated endogenously in hospital cost models.

Stimulation of DNA synthesis in murine lymphocytes by the drug swainsonine: immunomodulatory properties

Swainsonine, an inhibitor of Golgi alpha-mannosidase II, has recently been shown to have potent antimetastatic activity in experimental metastasis assays. In the case of systemic administration, the possible mechanism of action is unknown; the results reported here indicate that it can be explained at least in part by swainsonine stimulation of lymphocyte proliferation. In the present experiments, the standard in vitro mitogenic stimulation assay was used to test the effect of swainsonine on spleen cells. Treatment of spleen cell cultures with the optimum concentrations of the drug enhanced proliferation by 80-146%, as measured by (3H) thymidine incorporation, relative to untreated cultures. Similarly, when spleen cell cultures were prepared from mice maintained on swainsonine-supplemented drinking water, proliferation was stimulated at least 3-fold relative to cultures derived from animals maintained on regular water. The enhanced mitogenesis is apparently not directly related to increased expression of Concanavalin A (Con A) binding sites, since swainsonine induced mitogenesis is not inhibited by alpha-methyl-mannoside in contrast to Con A induced mitogenesis which is completely inhibited. These results suggest that the antimetastatic effect of systemically administered swainsonine is at least in part related to its ability to enhance proliferation of those specific cell populations involved in immune surveillance. This represents the first demonstration of a mechanism of action of swainsonine on the immune system.

Early histopathologic and ultrastructural alterations in femorotibial joints of partial medial meniscectomized guinea pigs

The articular cartilage from femorotibial joints of partial medial meniscectomized male guinea pigs was evaluated at 24, 48, 72, and 96 hours post-surgery to determine the sequential histopathologic and ultrastructural alterations. At 24 hours post-surgery, histopathologic alterations were in the superficial and middle layers and consisted of degeneration and necrosis of chondrocytes and minimal decreased intensity of toluidine blue matrix staining. Changes in chondrocytes and matrix became progressively more extensive 48 hours after surgery. Ultrastructurally, the changes in the superficial matrix appeared to be the result of loss of the fine granular material interspersed between collagen fibers. At 72 and 96 hours post-surgery, chondrocyte loss was extensive and surface fibrillation was seen. These findings suggested that chondrocyte death was the initial important event which led to progressive severe cartilage degeneration in this model.

Investigation of the antimetastatic effects of agents that inhibit cell adhesion or protein glycosylation

In this overview the authors describe their recent attempts to specifically interfere with the metastatic spread of B16-F10 melanoma cells. Using the experimental metastasis model system, inhibitory effects of (1) coinjection of cells with synthetic peptides derived from the glycoprotein fibronectin, which possess the ability to disrupt cell adhesion, and (2) treatment of cells with inhibitors of protein glycosylation and oligosaccharide processing have been examined.

A redescription of the life cycle of Eimeria mitis Tyzzer, 1929

Ten-day-old broiler chickens were inoculated with oocysts of a characterized strain of Eimeria mitis, and tissues were fixed at 4, 8, or 24-h intervals after inoculation for histopathological examination. Tissue collections were initiated at the time of inoculation and extended up to 168 h postinoculation. The preferred site of development of E. mitis was found to be the ileum although more limited development of the parasite also took in the jejunum, cecal pouches, cloaca, and bursa of Fabricius. No distinctive and consistent intestinal lesions were macroscopically evident even in heavily parasitized chickens. The prepatent period was approximately 92 h postinoculation. The histopathological features of the E. mitis infections were characterized using conventional bright-field microscopy as well as both scanning and transmission electron microscopy. No extra-intestinal development of the parasite was observed.

Competition in health care markets and the development of alternative forms of service delivery

This paper examines whether alternative forms of health care delivery locate in highly competitive health service markets. The analysis uses cross-sectional Florida data on the penetration of HMOs, ambulatory surgery centers, urgent care centers, hospices and home health programs in local markets characterized by varying levels of competitiveness among hospitals and among physicians. The results show generally that the development of these newer forms of service delivery are not systematically linked to inter-hospital competition but are influenced by physician supply and insurance demand. The potential contribution of such development to cost-containment efforts is thus questioned.

Inhibition of experimental metastasis by castanospermine in mice: blockage of two distinct stages of tumor colonization by oligosaccharide processing inhibitors

The extent of maturation of the oligosaccharide subunits of tumor cell glycoproteins appears to correlate with malignant potential, suggesting that modification of oligosaccharide structures may alter metastatic capacity. Castanospermine, a recently discovered inhibitor of glucosidase I, was tested for its effect on experimental metastasis of B16-F10 murine melanoma cells and was compared to treatment with swainsonine and tunicamycin. All three drugs block different steps in the pathway of glycoprotein processing yet each was a potent inhibitor of pulmonary colonization after i.v. injection of treated cells into C57BL/6 mice (greater than or equal to 80% inhibition). This result indicates a generality of inhibition of experimental metastasis by blockage of protein glycosylation or oligosaccharide processing and strongly implicates carbohydrate residues in at least one critical step of the metastatic cascade. Cytotoxic side effects could not account for the inhibitory activity. In order to identify a possible mechanism of inhibition of colonization, the adhesive behavior and pulmonary retention properties of B16-F10 cells treated with the above inhibitors were examined. Tunicamycin-treated B16-F10 cells exhibited poor adhesion to substrate-adsorbed fibronectin and laminin, whereas both castanospermine- and swainsonine-treated cells possessed near normal adhesive capacity; furthermore, the initial rate of loss of tunicamycin-treated cells from the lungs of mice was substantially greater than either control, castanospermine- or swainsonine-treated cells. These data suggest that these processing inhibitors can block experimental metastasis by at least two different mechanisms. The antimetastatic effect of tunicamycin may be related to interference in tumor cell-extracellular matrix interactions, whereas treatment with castanospermine or swainsonine appears to block at a stage distal to initial tumor cell arrest.

Hepatic peroxisomal changes induced by a tetrazole-substituted alkoxyacetophenone in rats and comparison with other species

Previous work in this laboratory indicated that compound LY171883, a tetrazole-substituted alkoxyacetophenone with leukotriene D4 antagonist activity, caused dose-related hepatomegaly in rodents without other histological evidence of liver toxicity. In the present studies, administration of LY171883 at dietary concentrations of 0.25 or 0.50% to rats for 2 weeks increased peroxisomal beta-oxidation, catalase activity, and peroxisome volume fraction in the liver. The effects were dose-related and corresponded with increases in liver weight. Dietary concentrations of 0.05 and 0.1% LY171883 did not significantly alter peroxisome morphology, enzyme activity, or liver weight. Serum triglycerides were lowered equivalently by all four dietary concentrations of LY171883, indicating that the hypotriglyceridemia was dissociated from induction of peroxisomal beta-oxidation. The hepatic effects in rats reversed within 16 days after discontinuing treatment with LY171883. Liver weight and peroxisomal enzyme activities were increased in mice by LY171883 in a manner comparable to that observed in rats, whereas hamsters were less responsive. In guinea pigs there was a minor increase in beta-oxidation at a toxic dose of LY171883, but no change in catalase or liver weight. Neither hepatomegaly nor induction of peroxisomal enzymes occurred in beagle dogs or rhesus monkeys given LY171883. Since the hepatic effects of LY171883 in rats are not observed in higher species at a significant multiple of the anticipated clinical dose, it is unlikely that such effects will occur in humans.

Oligosaccharide modification by swainsonine treatment inhibits pulmonary colonization by B16-F10 murine melanoma cells

Oligosaccharide moieties of cell-surface glycoconjugates are thought to be involved in recognition events associated with tumor metastasis and invasion. Using swainsonine (SW), an inhibitor of Golgi alpha-mannosidase II that results in the formation of hybrid-type oligosaccharides on N-linked glycoproteins, we have tested the hypothesis that specific glycan structures are required for pulmonary colonization by tumor cells. B16-F10 murine melanoma cells were treated with SW in growth medium and then injected intravenously into syngeneic C57BL/6 mice. This treatment resulted in dramatic inhibition of colonization, but it had no effect on B16-F10 viability or on cellular tumorigenicity after subcutaneous implantation. SW-treated radiolabeled B16-F10 cells were cleared from the lungs at a greater rate than control cells, suggesting that one effect of treatment is to alter tumor cell retention in the target organ. Our results implicate specific glycan structures in pulmonary colonization and offer a potential approach for identification of specific macromolecules involved in tumor cell-organ recognition during metastasis.

Canine atrioventricular node: scanning electron microscopy and enzyme histochemistry

Morphologic features of the canine atrioventricular (AV) node were evaluated, using histochemical cholinesterase reactions and scanning electron microscopy. Three distinct regions of the AV node were observed: the transitional zone, superficial AV node, and deep AV node. The transitional zone lacked distinct cellular arrangement, and the cells were large and round with extensive branching on the ends. Superficial AV nodal cells were elongated, tightly packed, and smaller than were transitional cells. The superficial AV node was the densest zone of the AV node. Cell-to-cell contact was end-to-end. Deep AV nodal cells were long, formed laminated fascicles, were larger than the superficial AV nodal cells, and were continuous with the AV bundle.

Travel distance as time price and the demand for mental health services

The ways in which health and mental health services are rationed is an area of growing concern among policy makers and administrators. More attention is being focused on how publicly supported mental health services are utilized and on how health care services in general are used depending upon how they are organized and reimbursed. Price is the marketplace's principal rationing device; the price and the consumption of a good are inversely related. Mental health services, however, tend to have a low money such that money price may not act as a rationing device for those services. This investigation examines the effect of travel distance, a surrogate for time price, from one's home to a community mental health center on the utilization of the center's services. A random sample of 224 clients was studied to determine the effect of their individual travel distances, ages, fees at the center, incomes, employment, gender, and the presence of substitutes on the length and intensity of utilization. Six log-linear regression models were specified and Ordinary Least Squares was used to determine the effect of each independent variable on the utilization of services. In each model travel distance as a measure of time price was found to be a significant factor in utilization. Time price elasticities of demand from this study are compared with elasticities reported in earlier time price studies in health care. The administrative and policy implications of the findings are discussed.

A preliminary study of Cu-, Cd- and Zn-binding components in the hepatopancreas of Palaemon elegans (Crustacea: Decapoda)

Three low molecular weight, metal-binding components have been isolated from the hepatopancreas of the shrimp Palaemon elegans. The two larger components P-I (11-15,000) and P-II (4-6000) were associated with large amounts of copper in field-collected and copper-exposed shrimps and with cadmium in shrimps exposed to elevated Cd concentrations. A smaller component, P-III was associated with zinc. The recovery of these components was dependent upon the use of a protease inhibitor and the reducing agent mercaptoethanol (2-M) during the separation procedure. Copper, zinc and cadmium are not evenly distributed between individual tissues of P. elegans, the highest concentrations occurring in the hepatopancreas, gills and eyes.

Scanning electron microscopy of the canine atrioventricular bundle and moderator band

The atrioventricular (AV) bundle and the moderator band in the canine heart were examined by scanning electron microscopy. The AV bundle and the moderator band both were comprised of large, cylindrically shaped cells. These cells were highly organized into bundles, with minimal lateral communication between bundles. There was extensive cell-to-cell communication between cells within a bundle. The end branching of individual cells was prominent, with some interbundle communication. These results are discussed in relationship to the electrophysiologic properties of the AV bundle and the conduction velocity.

Middle management and the clinician

It is my position that good clinicians are potentially the best managers for mental health programs. Nonetheless, clinicians who aspire to be managers must prepare themselves for the unsettling changes in self-image and ine one's interpersonal relationships. Also, one must assume a new place in an often chaotic maze that is supposed to be a rational hierarchy. Most important, clinical managers must seriously tackle a new set of theories and techniques to prepare themselves for middle and top level management responsibilities. The 1980s and 1990s are likely to offer great challenges and, one hopes, great rewards to those clinicians who are willing to dedicate their talents, skills, sensitivity, and courage to management.

Radiographic, macroscopic, and microscopic changes in growth plates of calves raised on hard flooring

The effect of flooring on the development of physeal and metaphyseal lesions of the limbs was studied in 1- to 5-month-old dairy calves. Calves were allotted to 2 groups. Group I was housed on a clay floor throughout the study and group II was housed on metal slats until weaned and then on concrete. Radiographs of the right thoracic limb of the animals were made 7 times during the experimental period and of the right thoracic and pelvic limbs at necropsy. Selected sections of the physeal regions of the distal part of the radius, metacarpus, metatarsus, and rib were examined microscopically. The physes of the limbs in the 2 groups had eosinophilic streaks and patches which originated in the germinal zone and were associated with blood vessels. These foci varied from small streaks parallel to the chondrocyte columns to multiple horizontal branching patches in which cleft formation and necrosis interrupted the physis, resulting in osseous bridging. Remnants of necrotic cartilage or cartilage containing hypertrophied chondrocytes were located in the metaphysis adjacent to the areas of physeal disruption. Multiple undulations of the physes with variations in thickness and orientation of the chondrocyte columns occurred in the physes of all limbs examined. These areas did not interrupt the physis and were not associated with metaphyseal lesions. The ribs in both groups had focal areas of failure of endochondral ossification characterized by elongation of the hypertrophied zone, accumulation of fibrin and hemorrhage in the zone of provisional calcification, and retention of cartilage within the metaphysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Sperm specific antigen(s) in detergent extract of rhesus monkey spermatozoa

Sperm surface antigens were prepared by detergent extraction (Hyamine-Triton, Rohm and Haas Co., Philadelphia, PA) of spermatozoa from rhesus monkeys. Heterologous antisera against the extracts were produced in female New Zealand White (NZW) rabbits by hyperimmunization. The antiserum was absorbed initially with sperm-free monkey seminal plasma and then with lyophilized tissue homogenates of liver, kidney, spleen, and pancreas from male rhesus monkeys. The unabsorbed antiserum produced at least three precipitin lines against detergent extract in double immunodiffusion tests and possessed sperm immobilization and sperm agglutination antibody activity. The absorbed antiserum showed one precipitin line against the detergent extract and retained sperm agglutination antibody activity only. The sperm agglutination antibody in the absorbed antiserum was completely removed by either epididymal or washed ejaculated rhesus monkey spermatozoa. The same results were obtained with ammonium-sulfate-precipitated immunoglobulin preparations. Immunoelectrophoresis revealed only one precipitation line with the absorbed immunoglobulin preparation. It is concluded that Hyamine-Triton extract of rhesus monkey spermatozoa contains a component which can be characterized as sperm-specific by immunoabsorption techniques and is apparently associated with sperm agglutination but not with immobilization.

Effect of ionophores on survival, penetration, and development of Eimeria tenella sporozoites in vitro

Free Eimeria tenella sporozoites were exposed to the anticoccidial ionophores monensin, lasalocid, narasin, or salinomycin for 4 hr at 40 C, whereupon the drugs were removed by dilution centrifugation and the parasites inoculated into cultures of chick kidney cells. Cultures were fixed and stained at 4 and 96 hr postinoculation to determine the effect of ionophore uptake by the extracellular sporozoites on invasion and development. Pretreatment with each of these antibiotics significantly reduced the number of intracellular sporozoites and dramatically inhibited asexual development. These effects were dose-dependent. Exposure of free (extracellular) sporozoites to monensin at 40 C caused a significant decline in the number of surviving organisms over time as compared to nontreated sporozoites. This response also appeared to be dose-dependent. Scanning and transmission electron microscopy revealed that the surface of the treated sporozoites was very irregular and the organisms often exhibited a gross swelling. These results indicated that free Eimeria tenella sporozoites may incorporate a potentially lethal concentration of the polyether ionophorous antibiotics and that a coccidiocidal activity may be expressed whether or not penetration of host's cells occurs.

The impact of mental health services on medical care utilization: economic and organizational implications

A wealth of studies support the assertion that patients seen by medical doctors for physical complaints can often be helped by psychotherapeutic intervention. Many physical ailments have been linked to emotional problems, and practitioners are beginning to understand that emotional and physical health are highly interrelated. Even very brief mental health intervention can reduce the number of visits for medical care, the studies show. Despite some obvious methodological shortcomings, past studies and literature reviews strongly endorse the development of a closer working relationship between mental health and physical health professionals. The need for extensive additional research with sound methodological design is discussed. The economic and organizational implications of this relationship are also explored from the perspectives of physical and mental health practitioners, patients, group health plans, and third-party payers.

Electron microscopy of fibers and discs of hemoglobin S having sixfold symmetry

Aggregated forms of deoxyhemoglobin S were examined with a field emission transmission electron microscope. Images of isolated helical fibers were obtained from sickled cell lysates stained directly on the electron microscope grid. Optical and digital analyses of the electron micrographs showed that the fibers are similar to those characterized by J. T. Finch, M. F. Perutz, J. F. Bertles, and J. Döbler [(1973) Proc. Natl. Acad. Sci. USA 70, 718-722] in that they consist of stacked discs each composed of six hemoglobin molecules. The fibers exhibit an outer diameter of 160-170 A and an inner diameter of about 60 A with an axial spacing of 58 A per disc. The fiber can be described as a helix consisting of 56 discs per helical turn. We observed discs of six hemoglobin molecules, which may be stable substructural components of the fibers. They were observed in preparations of hemoglobin fibers and exhibited 6-fold symmetry by power spectrum analysis. A reconstructed image of a disc digitally filtered for 6-fold symmetry has a maximum external diameter of approximately 170 A and a central hole of 60 A diameter and is similar to the axial projection of a single disc from a low-resolution, three-dimensional reconstructed model of a fiber.

A comparison of the prophylactic and therapeutic effects of poly I:C and endotoxin in mice infected with Mengo virus

We have compared the protective effect in AKR mice of poly I:C and bacterial endotoxins against lethal doses of Mengo virus. Administered intravenously or intraperitoneally, both interferon inducers protected mice to about the same extent from virus challenges of 2-3 LD50's. Endotoxin, however, was unable to protect the mice effectively against higher challenge doses of virus. Evidence is presented that the level of protection afforded by both inducers is related to the level of circulating interferon produced. We have also shown that a single intravenous dose of poly I:C results in the appearance of two distinct bursts of interferon activity, with maxima at about 2 h and 9 h post injection. Endotoxin, on the other hand, produced only one peak of activity, at 2 h post injection.