A system to measure isomeric state half-lives in the 10 ns to 10 µs range.

The Isomeric State Measurement System (SISMEI) was developed to search for isomeric nuclear states produced by fusion-evaporation reactions. The SISMEI consists of 10 plastic phoswich telescopes, two lead shields, one NaI(Tl) scintillation detector, two Compton suppressed HPGe γ-ray detectors, and a cone with a recoil product catcher. The new system was tested at the 8 UD Pelletron tandem accelerator of the University of São Paulo with the measurement of two known isomeric states: (54)Fe, 10(+) state (E = 6527.1 (11) keV, T(1/2) = 364(7) ns) and the 5/2(+) state of (19)F (E = 197.143 (4) keV, T(1/2) = 89.3 (10) ns). The results indicate that the system is capable of identifying delayed transitions, of measuring isomeric state lifetimes, and of identifying the feeding transitions of the isomeric state through the delayed γ-γ coincidence method. The measured half-life for the 10(+) state was T(1/2) = 365(14) ns and for the 5/2(+) state, 100(36) ns.

Repopulation of donor heart by recipient bone marrow-derived dendritic cells prior to transplantation causes acute rejection by both the allogeneic and syngeneic recipient.

Experimental studies on allogeneic transplantation have shown that recipient dendritic cells (DC) play a role in peripheral tolerance as well as in rejection of allografts. It is not known whether DC exert their tolerogenic function in recipient lymphoid tissue, and whether they process shed alloantigen in the graft itself. To answer this question we created a chimeric heart model deprived of its own DC and repopulated by recipient DC. The rationale for this model was to observe whether recipient DC located in the graft attenuate recruitment and stimulation of recipient lymphocytes, subsequently prolonging graft survival. Vascularized bone marrow transplants (VBMTx) from the prospective recipient to the lethally irradiated heart donor, which function for a period of 14 days, were used to replace donor DC with prospective recipient DC. Hearts from chimeric LEW rats (with BN DC) were transplanted to untreated BN rats. Also, hearts from chimeric LEW rats (with BN DC) were returned to untreated LEW rats. Replacement of the donor heart with recipient DC did not prolong graft survival. Rather, it initiated a rejection reaction that was already present in the donor. Recipient DC retained their immunogenic properties also when the graft was returned back to a donor strain animal.

Donor DNA can be detected in recipient tissues during rejection of allograft.

The main source of donor DNA in recipients of allograft are "passenger" cells. It is claimed that they are responsible for the posttransplantation microchimerism and prolongation of allograft survival. We have observed that besides cellular microchimerism, donor DNA can be found in the recipient tissues at the time of rejection of the allograft. In this study, we provide evidence for the presence in the recipient of both DNA in "passenger cells" and free DNA in tissues at the terminal stage of rejection. Male BN (RT1 n) rat heart or skin was transplanted to female LEW (RT1 l) rats followed by a vascularized bone marrow in a hindlimb transplant. In another group, heart and skin were transplanted followed by immediate i.v. infusion of donor-type bone marrow cells. CsA was given in a dose of 17 mg/kg body weight for 30 days, then the rats were followed up until day 100 unless rejection occurred earlier. LEW blood, spleen, mesenteric node and bone marrow cells were stained with moAb OX27 specific for BN but not LEW. Genomic male DNA was isolated and amplified with SRY oligonucleotide. At day 30 and day 100 cellular microchimerism was detected in blood, spleen, nodes and bone marrow cells. Donor DNA was detected in recipient skin, liver and heart extracts, as well as lymphoid organs, at the time of rejection of allograft, but not when the rats were maintained on CsA. Taken together, donor DNAwas detected in recipient tissues at the time of heart or skin rejection. It appeared to be released from cells of rejecting grafts and not from "passenger" cells, representing only a minor cellular mass compared with the graft.

The madness of Nietzsche: a misdiagnosis of the millennium?

This article represents a personal discussion about Nietzsche's mental illness, which formed part of a larger paper 'The masks of Nietzsche and eternal return of the repressed'. This was presented at the 6th Annual Conference of The Friedrich Nietzsche Society, September 1996, Manchester UK, as reported by Nussbaumer-Benz (1998).

DNA from rejecting allografts can be detected in recipient nonlymphoid tissues.

The main source of donor DNA in recipients of allograft are "passenger" cells. They are claimed to be responsible for the posttransplantation microchimerism and prolongation of allograft survival. We have noticed that beside of the cellular microchimerism, donor DNA can be found in the recipient tissues at the time of rejection of allograft. In this study we provide evidence for presence in the recipient of both, DNA in "passenger cells" and free DNA in tissues at terminal stage of rejection. Male BN (RTIn) rat heart or skin were transplanted to female LEW (RTII) rats followed by a vascularized bone marrow in hind-limb transplant. CsA was given in a dose of 17mg/kg b.w. for 30 days, then rats were followed until day 100 unless rejection occurred earlier. LEW blood, spleen, mesenteric node and bone marrow cells were stained with moAb OX27 specific for BN but not LEW. Genomic male DNA was isolated and amplified with SRY oligonucleotide. At day 30 and 100 cellular microchimerism was detected in blood, spleen, nodes and bone marrow cells. Donor DNA was detected in recipient skin, liver and heart extracts, beside of lymphoid organs, at the time of rejection of allograft but not when rats were maintained on CsA. Taken together, donor DNA can be detected in recipient tissues at the time of heart or skin rejection. It seems to be released from cells of rejecting grafts and not from "passenger" cells representing only a minor cellular mass compared with the graft.

Skin allografts--lymph veiled (dendritic) cells are responsible for initiation of rejection in canine skin/SCID mouse chimera model.

Skin allografts are acutely rejected despite of intensive immunosuppressive therapy. Resistance of skin dendritic cells to immunosuppressive drugs and irradiation may be responsible for this phenomenon. Skin allograft is a site of interaction between the dendritic cells and lymphocytes of the donor and host origin and "direct" and "indirect" pathway of antigen presentation. Increasing evidence supports the significant role for the "indirect" allorecognition in graft rejection. To investigate a critical role of skin dendritic cells in the "indirect" allorecognition and graft destruction we have used a canine skin to severe-combined-immunodeficient (SCID)-mice transplantation model. At the time the skin grafts were deprived of own dendritic (Langerhans) cells, SCID mice were reconstituted with allogeneic canine whole lymph leukocytes, lymph lymphocytes, lymph veiled (dendritic) cells or peripheral blood mononuclear cells, and an early phase of skin rejection was evaluated in histopathological studies. We demonstrated that circulating canine allogeneic veiled cells facilitate recruitment of T lymphocytes into skin graft and promote an extensive graft destruction, compared to the less expressed effect of allogeneic peripheral lymph lymphocytes or blood mononuclear cells. These drug and radiation-resistant dendritic cells may be responsible for initiation of the difficult to control rejection process.

Body distribution of syngeneic and allogeneic cells from vascularized bone marrow graft.

In the previous studies we showed that vascularized bone marrow graft (VBMtx) in transplanted rat hind limb brings about complete repopulation of syngeneic recipient BM cavities and lymphoid organs within 10 days. Transplantation of an equivalent number of bone marrow cells (BMC) in suspension did not produce repopulation until day 30. In this study we present data on transplantation of allogeneic VBM and compare them with those obtained in a syngeneic combination. In the LEW or BN to LEW combination BM cells were labelled with 51Cr, injected i.v., 24 h later the hind limb was amputated and transplanted to a LEW rat. BM cells emigrated from the transplanted limb to the recipient and distributed in BM cavities and lymphoid tissues. In the LEW to LEW combination the level of radioactivity in recipient tibia was after 24 h 0.85, in spleen 2.43, in mesenteric lymph node 0.52%/g of tissue, whereas in the BN to LEW model it was 0.11, 1.83 and 0.15%, respectively. The calculated numbers of BM cells which populated recipient tissues were 8-10-times lower in the allogeneic compared with syngeneic combination. This was probably due to the nonspecific elimination of some subsets of BM cells (allogeneic BMC cytotoxicity). Administration of anti-asialo GMI antiserum to the recipient abrogated the cytotoxic effect. Taken together, major differences in kinetics of seeding and repopulation of BMC from VBMTx were found. Elimination of recipient NK cells with AAGMI antiserum attenuated the nonspecific cytotoxic effect. This protocol allows protection of the grafted BMC and increases the efficacy of the transplant.

Microchimerism following allogeneic vascularized bone marrow transplantation--its possible role in induction of posttransplantation tolerance.

We have noticed that bone marrow transplanted in a vascularized limb graft providing a continuous supply of donor BMC may prolong the survival time of skin graft from the same donor. The question arises whether the raised microchimerism plays a role in the prolonged survival of skin allograft. The aim of the study was to follow the development of microchimerism after allogeneic vascularized bone marrow transplantation (VBMTx) concomitantly with the rejection processes of transplanted skin. The BN rats served as donors and LEW rats as recipients of VBMTx and free skin flap allograft. Hind limb was transplanted followed by a full-thickness skin graft on the dorsum. Cellular microchimerism was investigated in recipients of VBMTx and skin grafts in blood, spleen, mesenteric lymph node and bone marrow with monoclonal antibody OX27 directed against MHC class I polymorthic RTI on BN cells and quantitatively analysed in FACStar. In VBMTx group free skin flap survived 70 days after weaning of CsA. Intravenous infusion of BMC in suspension equivalent to that grafted in hind limb did not prolong skin graft survival after cessation of CsA therapy. Donor-derived cells could be detected in VBMTx recipients as long 70 days after wearing of CsA but not in recipients of i.v. suspension BMC grafting.

Cyclosporin A decreases lymphocyte migration to the heart allograft through suppression of their L-selectin expression.

Cyclosporin A (CsA) changes the distribution of the circulating pool of lymphocytes and decreases their traffic to organ allograft. The mechanism of this process is complex and includes, among others, inhibition of induction of nuclear factor of activated T cells and suppression of GM CSF and E-selectin expression. We studied the expression adhesion molecules CD11a, CD18, CD44, CD54 and CD62L on the thoracic duct lymphocytes of rats treated with CsA. The 7-day administration of CsA evidently decreased the expression of CD62L but did not affect the other adhesion molecules. Lower concentration of CD62L molecules on the surface of circulating lymphocytes may influence their migration to allograft and distribution in host lymphoid tissues.

Globus hystericus or depressivus?

Globus hystericus has been often classified as a conversion disorder. More than half of the sufferers are overtly depressed and only a handful have hysterical personality. It is argued that it might be more appropriately viewed as a psychophysiological symptom of depression that responds to antidepressant treatment.

Tolerance induction following allogeneic vascularized bone marrow transplantation--the possible role of microchimerism.

We have noticed that bone marrow transplanted in a vascularized limb graft, providing a continuous supply of donor bone marrow cells (BMC), may prolong the survival time of a skin graft from the same donor. The question arises whether the microchimerism raised plays a role in the prolonged survival of skin allografts. The aim of the study was to follow the development of microchimerism after allogeneic vascularized bone marrow transplantation (VBMTx) concomitantly with the rejection process of transplanted skin. Brown Norway (BN) rats served as donors and Lewis rats as recipients of VBMTx and free skin flap allografts. A hind limb was transplanted, followed by a full-thickness skin graft on the dorsum. Cellular microchimerism was investigated in recipients of VBMTx and skin grafts in blood, spleen, mesenteric lymph node, and bone marrow with the monoclonal antibody OX27 directed against MHC class I polymorphic RT1 on BN cells and quantitatively analyzed in a FACStar. In the VBMTx group, the free skin flap survived 70 days after weaning off cyclosporine A (CsA). An intravenous infusion of BMC in suspension equivalent to that grafted in the hind limb did not prolong skin graft survival after cessation of CsA therapy. Donor-derived cells could be detected in VBMTx recipients as long 70 days after weaning off CsA but not in recipients of i.v. suspension BMC grafting.