Long-term Transplants Research Articles

Clinical Studies with the Nova Ise for IMg2+

The Nova ISE for IMg2+ was utilized to examine IMg2+ in plasma and serum of patients with a variety of pathophysiologic and disease syndromes (e.g., long-term renal transplants [LTRT], during and before cardiac surgery, migraine headaches, head trauma, pregnancy, chronic fatigue syndrome [CFS], non-insulin dependent diabetes mellitus [NIDDM], asthma and after excessive dietary intake of Mg). The results indicate that LTRT treated with cyclosporin A, migraine, head trauma, pregnancy, NIDDM, diseased pregnant, and asthmatic patients all on the average, exhibit significant depression in IMg2+ but not total Mg (TMg). Patients with CFS failed to exhibit changes in serum IMg2+ or TMg levels. Increased dietary load of Mg, for only 6 days, resulted in significant elevations of serum IMg2+ but not TMg. Correlations between the clinical course of several of these syndromes and the fall in IMg2+ were found. The Ca2+/Mg2+ ratio appears to be an important guide for signs of peripheral vasoconstriction and or spasm and possibly enhanced atherogenesis. Overall, the data point to important uses for ISE's for IMg2+ in the diagnosis and treatment of disease states.

Cellular and molecular composition of human skin in long-term xenografts on SCID mice.

We report on the immunophenotypical characterization of adult human skin transplanted onto severe combined immunodeficient (SCID) mice. Thirty animals were followed for up to 12 months after receiving split-thickness xenografts, of which 28 were tolerated for the whole test period. Antigen mapping revealed an almost complete preservation of human cellular and extracellular tissue components in long-term transplants including skin immune cells (Langerhans-cells, macrophages, lymphocytes) and also parts of the engrafted endothelium. Hence, xenografts on SCID mice offer a versatile experimental tool for the in vivo study of both human skin immune cell function and endothelial cell-mediated interactions in an environment completely devoid of interferences by adoptive host immune response.

Long-term transplants of mouse trisomy 16 hippocampal neurons, a model for down's syndrome, do not develop Alzheimer's disease neuropathology

Hippocampal tissue from embryonic day 15–17 fetal mice, euploid or trisomic for chromosome 16, was transplanted into the striatum or the lateral ventricle of 6–8 week old female C57B1/6 mice. After 6–14 months of survival, host brains were sectioned and the grafts were examined by histochemical techniques and by immunocytochemistry for antigens present in pathological brain structures of Alzheimer's disease (AD) patients. Nissl-stained grafts contained aggregations of neurons similar tothe pyramidal or the granule cell layers of the normal adult mouse hippocampus. No obvious morphological difference was detected between trisomic and control transplants. The monoclonal antibody Alz-50, which recognizes the paired helical filaments characteristics of AD, or an antibody raised to β-amyloid peptide, did not reveal neurodegeneration in these grafts. Antibodies against ubiquitin, 200 kDa subunit of neurofilament, α 1-antichymotrypsin and tau also did not demonstrate AD-type immunoreactivity in the trisomic or control grafts. Thioflavin S- or silver stained-sections were also negative. We conclude that transplanted hippocampal tissue from the trisomy 16 mouse does not represent an animal model for AD-type neurodegeneration. These results differ from those of Richards et al., EMBO J. (10) (1991) 297–303, who reported AD-type degeneration in trisomy 16 hippocampal transplants.

Differential effects of long-term transplantation on the growth of cortical neurons containing parvalbumin or calbindin.

Numerical density and morphology of the two main GABAergic neuronal classes, the parvalbumin (PV) and calbindin- (CaBP)-containing nerve cells were investigated in long-term neocortical transplants in rats. It was observed that 4 months after the transplantation both CaBP- and PV-immunoreactive neurons survive and grow in neocortical grafts. However, the numerical density of PV cells decreased to about half of the control value (host cortex), while the density of CaBP-positive cells was 25-60% of that seen in the host cortex, depending on the degree of integration of the graft. The mean diameter of PV neurons rose to double of the control value, while the size of CaBP-positive perikarya did not change. This indicates that GABAergic neurons with hypertrophic perikarya (Bragin et al. 1991a) are identical to PV neurons. On the basis of these qualitative and quantitative morphological data it is concluded that PV- and CaBP-containing GABA cells in the transplant exhibit different sensitivities to transplantation-related structural and functional alterations.

Host dopaminergic afferents affect the development of DARPP-32 immunoreactivity in transplanted embryonic striatal neurons

Homotopic transplantation provides an interesting way to observe the relationships between developing cells and ingrowing host afferents. We have performed a complete and selective elimination of the mesostriatal dopaminergic system in adult rats to observe the influence of its absence on the development and chemical differentiation of embryonic striatal cells. Cell suspensions from striatal primordia of 14–15-day-old embryos were transplanted into host striata that were (i) neuron-depleted by kainic acid (control group) or (ii) deprived of dopamine by 6-hydroxy-dopamine prior to the neuronal depletion by kainic acid (experimental group). The expression of dopamine- and adenosine 3′,5′-monophosphate-regulated phosphoprotein (DARPP-32) by transplanted cells was observed in correlation with their innervation by host dopaminergic afferents which in turn were identified by tyrosine hydroxylase immunohistochemistry. Observations were made between four days and three months after transplantation. Four days after transplantation, no immunoreactivity for DARPP-32 was observed in transplants of control animals despite the presence of tyrosine hydroxylase-immunopositive fibers growing from the host to discrete cell clusters in the transplant. DARPP-32-labeled cells appeared soon afterwards. Six days after transplantation they displayed varying intensities of immunoreaction, ranging from just detectable to normal levels and were specifically targeted by developing tyrosine hydroxylase-immunopositive fibers. The number of DARPP-32-labeled cells increased rapidly and they formed increasingly compact clusters. Fourteen days after transplantation and afterwards, all the DARPP-32-labeled cells displayed an intensity of immunoreaction and a distribution comparable to that observed in long-term transplants. Transplants in the experimental hosts displayed the same organization and developmental features as the control transplants with the exception of DARPP-32 labeling which was not detected before eight days after transplantation. Ten days after transplantation, the distribution and intensity of DARPP-32 labeling was similar to that observed at six days in the control group. The evolution of DARPP-32 labeling after 10 days in the experimental group paralleled that observed six days post-transplantation and beyond in the control group. Dopaminergic mesostriatal host afferents are able to provide developing cells in grafted striatal tissues with normal innervation very rapidly. Despite this rapidity, the innervation does not seem to have any trophic influence on the general development of the transplant but does affect the onset time of the expression of neurochemical markers that are directly related to its synaptic function. The expression of DARPP-32 after one week in the absence of dopaminergic afferents suggests that the influence of extracellular dopamine supplied by other brain structures or extracellular mechanisms unrelated to dopaminergic systems or a genetic program are able to compensate for the lack of an adequate presynaptic element.

Reappearance of a normal circadian rhythm of blood pressure after cardiac transplantation

Twenty-four-hour blood pressure (BP) and heart rate profiles were recorded in 19 patients 1 and 7 months after cardiac transplantation using noninvasive ambulatory monitors and were analyzed using the periodogram method. These recordings were compared with those of control subjects matched for age, sex and daytime ambulatory BP. One month after transplantation, the nighttime decrease in systolic and diastolic BPs were attenuated in the patients as compared to the control subjects (p < 0.001). The daily oral dose of prednisolone was inversely correlated with the magnitude of the nighttime decreases in systolic and diastolic BPs (r = −0.47 and −0.53, p < 0.05). In contrast, 7 months after transplantation, the nighttime decrease in systolic and diastolic BPs reappeared in the patients and was of similar magnitude as that in the control subjects. When the immunosuppressive regimens during the 2 periods of recordings were compared, the reduction in the daily oral dose of prednisolone administered to the patients 7 months after transplantation was correlated with the observed increase in the day-night systolic and diastolic BP difference (r = 0.61, p < 0.01 and r = 0.51, p < 0.05). Thus, data show the reappearance of normal circadian BP profiles in patients with long-term heart transplants, and suggest that glucocorticoid administration may contribute to the abnormal nocturnal BP profiles observed 1 month after transplantation.

Electron microscopy of human first trimester and rat mid-term retinal cell transplants with long development time

The ultrastructure of rat to rat and human to rat long-term transplants of retinal cell transplants has been investigated. The human transplants were examined at 30 to 41 weeks of total age after conception. Rat homotransplants were nine to ten weeks of age after conception in four cases and 20 weeks in one case. Xenotransplanted rats were immunosuppressed with Cyclosporin A.Both xeno-and homotransplants can develop in the epiretinal or the subretinal space. The development is often heterogeneous. Photoreceptor cells can form both inner and outer segments as well as synaptic terminals. In regions corresponding to the inner plexiform layer, the adult complement of synapses has been seen, including advanced features like serial synapses as well as reciprocal synapses at bipolar cell dyads. Incompletely differentiated synapses of both amacrine and bipolar cell types have been observed, especially in rat epiretinal transplants. Ganglion cell processes have not been identified with certainty. Transplants from ...

Abnormal perikaryal immunoreactivity to the phosphorylated heavy neurofilament unit in intracerebral basal forebrain transplants

Grafts of Embryonic Day 14–15 basal forebrain tissue (medial septal/diagonal band nuclei) were transplanted into an aspirative fimbria-fornix cavity or the hippocampus of young adult rats. After extended periods of survival (1 and 2 years) the grafts were examined with immunocytochemical probes to identify specific types of neurons and assess the (spatial) distribution of the phosphorylated heavy neurofilament protein. Subpopulations of the long-term transplanted neurons expressed immunoreactivity to choline acetyltransferase (CAT) and the low-affinity nerve growth factor receptor (192-IgG). Axons from the grafted neurons, visualized with the monoclonal antibody RT97 to the M r 200,000 phosphorylated neurofilament unit, were observed to extend over the surfaces of the brain and connect with the host hippocampus. In subgroups of neurons without apparent axonal connections to the hippocampus, a change from axonal to cell body RT97 immunoreactivity was evident. A population of these neurons with abnormal neurofilament immunostaining in the soma was simultaneously identified as cholinergic with the CAT antibody. These studies indicate that abnormal changes can develop in the cytoskeleton of neurons in long-term intracerebral septal transplants. Although the reasons for this type of neurofilament modification in the grafted neurons are unknown, inappropriate terminal connections may be an important factor in the expression of this cytoskeletal change.

Magnetic Resonance Imaging of the Transplanted Kidney

Interstitial fibrosis is a frequent finding in biopsies from long-term renal allografts, and may be due to chronic cyclosporine nephrotoxicity or chronic rejection. In this study, long-term renal transplants were investigated with magnetic resonance (MR) imaging, and the results were correlated to histopathology and graft function. Seventeen patients were investigated with MR one to 10 years after transplantation and with simultaneous ultrasonographically guided cortical needle biopsy and function tests. Histopathology included semiquantitative grading of degree of fibrosis and quantitation of ratios of tubular structures to interstitial tissue. The correlation between the histopathological assessment of interstitial fibrosis and graft function was good. Poor differentiation between the renal cortex and the renal medulla at MR imaging was correlated to high degree of interstitial fibrosis in the kidney transplants as well as to reduced graft function. MR examination may thus be of value in the evaluation of long-term renal transplants with chronic functional changes.

Morphological Findings in Long-Term Pancreatic Tissue Transplants in the Anterior Eye Chamber of Rats

Morphological changes in 21-day-old embryonic and 2-day-old postnatal rat pancreatic tissue fragments transplanted into the anterior eye chamber of homologous animals for 74, 77, 180, and 534 days were investigated using light and electron microscopic, acetylcholinesterase enzyme, and immunohistochemical methods. The pancreatic acinar cells degenerated and were not observed at this stage of transplantation. The ductal system proliferated and partly differentiated into endocrine cells that subsequently formed many new islets of Langerhans as well. The structures of beta-, alpha-, delta-, and pancreatic polypeptide cells were found to be intact even 1.5 years after transplantation. In addition to this, the organization of these cells inside the islets is similar to that of normal pancreatic tissue. The transplanted tissue fragments were well vascularized with blood vessels and innervated also by serotonergic cells and acetylcholinesterase-positive neurons. It is concluded that pancreatic tissue fragments, with the exception of the acinar component, can grow and survive with intact structure in the anterior eye chamber of homologous rats for up to 1.5 years.

Magnetic Resonance Imaging of the Transplanted Kidney

Interstitial fibrosis is a frequent finding in biopsies from long-term renal allografts, and may be due to chronic cyclosporine nephrotoxicity or chronic rejection. In this study, long-term renal transplants were investigated with magnetic resonance (MR) imaging, and the results were correlated to histopathology and graft function. Seventeen patients were investigated with MR one to 10 years after transplantation and with simultaneous ultrasonographically guided cortical needle biopsy and function tests. Histopathology included semiquantitative grading of degree of fibrosis and quantitation of ratios of tubular structures to interstitial tissue. The correlation between the histopathological assessment of interstitial fibrosis and graft function was good. Poor differentiation between the renal cortex and the renal medulla at MR imaging was correlated to high degree of interstitial fibrosis in the kidney transplants as well as to reduced graft function. MR examination may thus be of value in the evaluation of long-term renal transplants with chronic functional changes.

The future of Medicare policy reform

The Medicare program, the largest health insurance program in the United States, is clearly at a crossroads as it enters its third decade. Historical increases in health care expenditures, plus a changing political and economic landscape, have set the groundwork for policy reform. Two basic reform strategies—reimbursement arrangements and program funding mechanisms—are discussed. In 1983, Congress enacted to Medicare the Prospective Payment System (PPS) which initiated a fundamental change in the way hospitals are paid for care delivered to Medicare beneficiaries. But the PPS is only a stepping-stone to broader reforms such as capitation. In addition, new methods of program funding may be necessary, especially in light of policymakers' considerations of coverage of serices such as long-term care and organ transplants.

THE EFFECTS OF CHEMICALLY AND PHYSICALLY DISPERSED OIL ON THE BRAIN CORAL DIPLOMA STRIGOSA (DANA)—A SUMMARY REVIEW

ABSTRACT The Coroil project in Bermuda has been an intensive, multidisciplinary study of the effects of physically and chemically dispersed Arabian light crude oil on the main reef-building coral in Bermuda, Diploria strigosa. This paper reviews the results of this three year study. Corals were exposed to dispersed oil in a flow system, using spectrofluorimetry and gas chromatography to characterize and quantify the dose. Appropriate controls were included in all experiments. The studies included effects of dispersed oil on survival and behavior, the uptake and depuration of petroleum hydrocarbons, photosynthesis by symbiotic zoo-xanthellae, and skeletal growth. In behavioral and growth studies, corals were dosed in the laboratory or in the field. Laboratory-dosed colonies were returned to the field to determine long-term effects. Exposure to 20 ppm of chemically dispersed oil for 24 hours induced various behavioral reactions, including tentacle retraction, tissue contraction and mesenterial filament extrusion. However, effects were typically sublethal, and recovery was usually evident within four days. These symptoms were not significant in long-term transplants. Using the alizarin red staining technique, no long-term effects on skeletal growth could be detected following any of our treatments. Depuration studies using (9-I4C) -phenanthrene and gas chromatographic analysis showed that the uptake of petroleum hydrocarbons by the tissue of Diploria was rapid, but 75 percent of the hydrocarbon dose was eliminated within 14 days. Photosynthesis studies showed a short-term inhibition of photosynthesis only by chemically dispersed oil, with lipid synthesis being most severely affected. Total recovery occurred within 24 hours of exposure.

Percutaneous insertion of a permanent hyperalimentation catheter.

• Patients with granulomatous enteritis or short-gut syndrome and those having long-term intravenous chemotherapy or bone marrow transplants may require hyperalimentation at home. A technique for percutaneous insertion of a permanent hyperalimentation catheter has provided satisfactory results and has reduced patient discomfort. Operator time is reduced and complications have been few to date. ( Arch Surg 1982;117:976-977)

Long-term transplants of infantile rat pituitaries cultivated in vitro and grafted into the anterior eye chamber of young cats.

DURING the past few years, we have made a number of attempts to obtain successful grafts between widely unrelated species of mammals. In most of these experiments the rat was used as the donor of the graft and the cat, an animal known for its refractoriness to foreign proteins, as receptor. The anterior eye chamber was chosen as the site of transplantation. In every experiment the anterior pituitary of 17-day old rats served as the graft, and kittens of between 21 and 60 days as graft receptors. In all, six cats with eighteen grafts were used as controls, and seventeen cats with eighty-three grafts as experimental animals. Early in the investigation it became evident that normal infantile rat pituitaries transplanted into the eye of the cat failed to survive for long periods. With one exception, where the grafted pituitary tissue was still present after thirty-five days, in twenty-four days the grafts were completely resorbed, although in every case vascular connexion with the host tissue was established.

Long-term transplants of infantile rat pituitaries cultivated in vitro and grafted in the anterior eye chamber of young cats.

Long-term transplants of infantile rat pituitaries cultivated in vitro and grafted in the anterior eye chamber of young cats.