Thymus transplantation restores the repertoires of forkhead box protein 3 (FoxP3)+ and FoxP3- T cells in complete DiGeorge anomaly.

The development of T cells with a regulatory phenotype after thymus transplantation has not been examined previously in complete DiGeorge anomaly (cDGA). Seven athymic infants with cDGA and non-maternal pretransplantation T cell clones were assessed. Pretransplantation forkhead box protein 3 (Foxp3)(+) T cells were detected in five of the subjects. Two subjects were studied in greater depth. T cell receptor variable ß chain (TCR-Vß) expression was assessed by flow cytometry. In both subjects, pretransplantation FoxP3(+) and total CD4(+) T cells showed restricted TCR-Vß expression. The development of naive T cells and diverse CD4(+) TCR-Vß repertoires following thymic transplantation indicated successful thymopoiesis from the thymic tissue grafts. Infants with atypical cDGA develop rashes and autoimmune phenomena before transplantation, requiring treatment with immunosuppression, which was discontinued successfully subsequent to the observed thymopoiesis. Post-transplantation, diverse TCR-Vß family expression was also observed in FoxP3(+) CD4(+) T cells. Interestingly, the percentages of each of the TCR-Vß families expressed on FoxP3(+) and total CD4(+) T cells differed significantly between these T lymphocyte subpopulations before transplantation. By 16 months post-transplantation, however, the percentages of expression of each TCR-Vß family became significantly similar between FoxP3(+) and total CD4(+) T cells. Sequencing of TCRBV DNA confirmed the presence of clonally amplified pretransplantation FoxP3(+) and FoxP3(-) T cells. After thymus transplantation, increased polyclonality was observed for both FoxP3(+) and FoxP3(-) cells, and pretransplantation FoxP3(+) and FoxP3(-) clonotypes essentially disappeared. Thus, post-transplantation thymic function was associated with the development of a diverse repertoire of FoxP3(+) T cells in cDGA, corresponding with immunological and clinical recovery.

Quantitative analysis of trace element concentrations in some gem-quality diamonds.

The geochemical signature of diamond-forming fluids can be used to unravel diamond-forming processes and is of potential use in the detection of so-called 'conflict' diamonds. While fluid-rich fibrous diamonds can be analyzed by a variety of techniques, very few data have been published for fluid-poor, gem-quality diamonds because of their very low impurity levels. Here we present a new ICPMS-based (ICPMS: inductively coupled plasma mass spectrometry) method for the analysis of trace element concentrations within fluid-poor, gem-quality diamonds. The method employs a closed-system laser ablation cell. Diamonds are ablated and the products trapped for later pre-concentration into solutions that are analyzed by sector-field ICPMS. We show that our limits of quantification for a wide range of elements are at the sub-pg to low pg level. The method is applied to a suite of 10 diamonds from the Cullinan Mine (previously known as Premier), South Africa, along with other diamonds from Siberia (Mir and Udachnaya) and Venezuela. The concentrations of a wide range of elements for all the samples (expressed by weight in the solid) are very low, with rare earth elements along with Y, Nb, Cs ranging from 0.01 to 2 ppb. Large ion lithophile elements (LILE) such as Rb and Ba vary from 1 to 30 ppb. Ti ranges from ppb levels up to 2 ppm. From the combined, currently small data set we observe two kinds of diamond-forming fluids within gem diamonds. One group has enrichments in LILE over Nb, whereas a second group has normalized LILE abundances more similar to those of Nb. These two groups bear some similarity to different groups of fluid-rich diamonds, providing some supporting evidence of a link between the parental fluids for both fluid-inclusion-rich and gem diamonds.

Factors affecting success of thymus transplantation for complete DiGeorge anomaly.

Thymus transplantation shows promise for the treatment of athymia in complete DiGeorge anomaly. This report reviews the effects of dose of thymus tissue, ABO compatibility, HLA matching, culture conditions, age of donor and immunosuppression of recipient on immune outcomes at 1 year after transplantation. Forty-nine athymic subjects have been treated with cultured postnatal allogeneic thymus tissue; 36 (73%) survive with only one subject on immunosuppression at 1.5 years. Of 31 surviving subjects more than 1 year after transplantation, 30 (97%) developed naive T cells, T-cell proliferative responses to mitogens and a diverse T-cell receptor beta variable (TCRBV) repertoire. The dose of thymus tissue, HLA matching and use of immunosuppression had nonsignificant effects on these outcome variables. Removal of deoxyguanosine from culture medium and length of culture did not adversely affect outcomes. Use of thymus tissue from donors over 1 month of age, versus under 1 month, resulted in higher total T-cell numbers (p = 0.03). However, this finding must be confirmed in a prospective trial. Although subtle immune effects may yet be associated with some of the factors tested, it is remarkable that consistently good immune outcomes result despite variation in dose, HLA matching and use of immunosuppression.

The effects of viral infections on renal transplants and their recipients.

A prospective study of viral infections occurring after 188 renal transplants in 167 patients showed active cytomegalovirus (CMV) infection after 52 per cent of transplantations. All 37 CMV seronegative cases who received grafts from seronegative donors remained free of infection, while 24 (70.6 per cent) of 34 seronegative recipients whose donors were seropositive developed primary CMV infection (p less than 0.001). The diagnosis of 92 per cent of these primary infections was made between one and two months after grafting. Secondary CMV infection was found in 71 (62 per cent) of 114 seropositive cases, and the frequency of infection was not affected by the CMV status of the renal donor. Neither acute rejection episodes nor total graft rejections were associated with primary or secondary infections. CMV was isolated from a colonic abscess and the relationship of the virus to the intestinal disease is discussed. Herpes simplex virus was isolated from 47 per cent of cases and 32 per cent had an increase in antibody titre. Zoster was seen in nine patients, representing an incidence of 3.4 per cent per year. Other viral or mycoplasmal infections diagnosed included 71 due to respiratory tract pathogens, and a single case of hepatitis B. None of these infections was particularly severe or frequent and no association with graft rejection was detected.

Determination of intravenous non-protein energy and nitrogen requirements in growing rats.

Two experiments were conducted to estimate total non-protein energy and nitrogen requirements in growing healthy male Wistar rats nourished by parenteral nutrition. In experiment 1, non-protein energy varying from 30 to 70 kcal/day/rat were administered to animals receiving a constant dose of 80 mg nitrogen, plus vitamins and minerals. In experiment 2, nitrogen dosages varying from 0 to 280 mg N/day/rat with a constant dose of 60 kcal non-protein energy were studied. The formulation of the amino acid solution used in both experiments was based upon recommended oral amino acid requirements for growing rats. Dextrose served as the source of non-protein energy. Weight gain and nitrogen balance during a 6-day experimental period were used to determine requirements. Plasma free amino acids were also analyzed to evaluate the amino acid solution. Results indicate that under total parenteral nutrition conditions 578 to 621 mg/kg body weight3/4 nitrogen and 171 to 182 kcal/kg body weight3/4 non-protein energy are required to achieve growth of approximately 3 g/day. Inconsistent responses of plasma amino acid concentrations to the amounts infused were observed. It is suggested that the determined requirements can be applied as guidelines to research using the rat as an animal model in total parenteral nutrition.

Immunofluorescence staining for the diagnosis of herpes encephalitis.

Direct immunofluorescence staining for herpes simplex virus was applied to cryostat sections of 43 specimens removed at brain biopsy. Herpes antigen was found in 10 specimens and virus was isolated from them. Antigen was found in one specimen from which virus was not isolated. Two specimens from which virus was isolated gave equivocal fluorescence. Thirty specimens gave no fluorescence or live virus. Immunofluorescence provided a diagnosis in three hr compared with 24-42 hr for virus isolation. Indirect immunofluorescence staining was applied to sections of brain removed at necropsy and fixed in formalin. Herpes antigen was found in sections of six of the 12 brains examined.