Benign tumors of heterotopic tissue in the thyroid gland: a report of two cases of lipomatous lesions

A report of two cases, concerning heterotopic nests of fat cells in the thyroid gland, is presented here together with a review of lipomatous lesions in the literature. Both cases involved patients who presented with goiter; one had Grave's disease and the other had adenomatous hyperplasia. The fat cells were principally located in the subcapsular areas and scattered among the follicles. The distribution of the immunohistochemical staining, and the morphologic characteristics of the adipose tissue, suggested a probable origin of the fat cells from inclusion nests during embryogenesis of the thyroid gland.     

The impact of a very high purity factor VIII concentrate on the immune system of human immunodeficiency virus-infected hemophiliacs: a randomized, prospective, two-year comparison with an intermediate purity concentrate [see comments]

Pathophysiologic considerations as well as non-comparative clinical results suggest that very high purity concentrates may slow immunologic deterioration in human immunodeficiency virus (HIV)-infected hemophiliacs. In an attempt to evaluate this hypothesis, we prospectively compared CD4 cell counts, skin testing responses, and changes of the clinical status in 20 asymptomatic HIV-positive hemophiliacs, randomly assigned to continue the treatment with an intermediate purity concentrate or to receive a very high purity product, purified by immunoaffinity chromatography with monoclonal antibodies. In the group switched to the very high purity concentrate there was no significant change of the CD4 cell counts over the 96-week follow-up period, whereas in the group continued on the intermediate purity concentrate, a highly significant decline was detected (P less than .013). Furthermore, in the very high purity group, four of six anergic patients at entry acquired reactivity to skin testing. The results of this study clearly support the use of very high purity concentrates for the replacement therapy of HIV-infected hemophiliacs.     

Spontaneous echocardiographic contrast within an unruptured sinus of Valsalva aneurysm: A potential embolic source diagnosed by transesophageal echocardiography

A 75-year-old male patient had an unexplained transient ischemic attack. Transesophageal echocardiography revealed a large, unruptured Sinus of Valsalva aneurysm which contained spontaneous echo contrast. This finding represents a potential source of embolism.     

Simultaneous measurement of gallbladder emptying with cholescintigraphy and US during infusion of physiologic doses of cholecystokinin: a comparison

Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying.     

Direct demonstration of transsynaptic degeneration in the human visual system: a comparison of retrograde and anterograde changes

Transneuronal degeneration of retinal ganglion cells was directly demonstrated in a patient who had unilateral removal of the striate cortex forty years prior to necropsy. For comparison, another case is presented showing anterograde transneuronal atrophy forty years after enucleation of one eye.     

Phylogenetic disparity influences the predominance of direct over indirect pathway of antigen presentation in islet xenotransplantation

BACKGROUND: Cellular immunity plays a major role in rejection of xenografted islets. Depending on the phylogenetical disparity, direct or indirect antigen presentation is predominant. The aim of this study was to analyze in vitro the predominance of direct or indirect presentation, and in vivo the effect of macrophage depletion on concordant and discordant islet xenograft survival. MATERIALS AND METHODS: In vitro, we performed mouse antirat and mouse antihuman mixed lymphocyte reactions (MLR) after depletion of responder or stimulator antigen-presenting cells. In vivo, streptozotocin-induced diabetic C57BL/6 mice were treated by gadolinium chloride to deplete macrophages and rat or human islets were transplanted under the kidney capsule. Islet function was followed by glycemia and xenografts were analyzed at regular intervals for histology. RESULTS: Mouse antirat MLR showed a predominant direct antigen presentation pathway, whereas in mouse antihuman MLR, direct and indirect pathways were similarly involved. Survival of rat islets was not modified by GdCl therapy. In contrast, survival of human islets was significantly prolonged in GdCl-treated mice. Macrophage infiltration was decreased in concordant and discordant GdCl-treated xenografts at day 4, compared to controls. At day 15, macrophage infiltration was similar in all groups. DISCUSSION: Our results indicate that direct antigen presentation is dominant in rejection of concordant islet xenografts and cannot be influenced by host macrophage depletion. Both direct and indirect antigen presentation are involved in rejection of discordant xenogeneic islets. Macrophage depletion or inhibition should be considered as therapeutic tool for discordant islet xenotransplantation.     

Transplantation of discordant xenogeneic islets using repeated therapy with anti-CD154

BACKGROUND: Costimulatory blockade has been shown to allow long-term survival of xenogeneic islets. The aim of the present study was to analyze the possibility of xenogeneic islet retransplantation using costimulatory blockade. METHODS: Streptozotocin-induced diabetic C57/BL6 mice were transplanted with 1000 human islet equivalents. After 14 days, mice were nephrectomized (graftectomy) and retransplanted with human leukocyte antigen (HLA)-mismatched human islets under contralateral kidney capsule. Four groups were performed: I: all transplants (Tx) without MR1; II: first Tx without MR1, second Tx with MR1; III: first Tx with MR1, second Tx without MR1; and IV: all Tx with MR1. Recipient serums were analyzed by cross-match for serum-mediated cytotoxicity against human lymphocytes and islets. RESULTS: In group I, the second graft rejection was accelerated (graft survival, 5 +/- 3 days) compared with the first graft without MR1 (13 +/- 7 days). In groups II and III, second graft survivals were 16 +/-1 3 and 62 +/- 15 days, respectively. In group IV, second graft function was maintained for >100 days. Pretransplant cross-matches were all negative. Post-second Tx cross-matches were positive in groups I and II and negative in group IV. In group III, post-second Tx cross-matches were negative only for cells with HLA molecules present in the first donor. CONCLUSIONS: MR1 was unable to induce tolerance after sensitization. MR1 given at the first Tx only allowed prolonged survival of the second Tx, but rejection still occurred with development of antibodies against molecules not present on first donor cells, indicating that costimulatory blockade does not induce linked-suppression against species-specific antigens of xenografts but can induce donor-specific unresponsiveness. MR1 given for all sequential transplantation allowed long-term regraft survival and prevented occurrence of antidonor antibodies.