Immune reconstitution following rabbit antithymocyte globulin.

Depletional induction therapies are routinely used to prevent acute rejection and improve transplant outcome. The effects of depleting agents on T-cell subsets and subsequent T-cell reconstitution are incompletely defined. We used flow cytometry to examine the effects of rabbit antithymocyte globulin (rATG) on the peripheral T-cell repertoire of pediatric and adult renal transplant recipients. We found that while rATG effectively depleted CD45RA+CD27+ naïve and CD45RO+CD27+ central memory CD4+ T cells, it had little effect on CD45RO+CD27- CD4+ effector memory or CD45RA+CD31-, CD45RO+CD27+ and CD45RO+CD27- CD8+ T cell subsets. When we performed a kinetic analysis of CD31+ recent thymic emigrants and CD45RA+/RO+ T cells, we found evidence for both thymopoiesis and homeostatic proliferation contributing to immune reconstitution. We additionally examined the impact of rATG on peripheral CD4+Foxp3+ T cells. We found that in adults, administration of rATG-induced peripheral expansion and new thymic emigration of T cells with a Treg phenotype, while CD4+Foxp3+ T cells of thymic origin predominated in children, providing the first evidence that rATG induces Treg in vivo. Collectively our data indicate that rATG alters the balance of regulatory to memory effector T cells posttransplant, providing an explanation for how it positively impacts transplant outcome.

Single center observation of the role of pre-existing HLA-DP antibodies in humoral rejection following renal transplantation.

HLA antigens, including HLA-A, B, C, DR and DQ have long been known to have an effect on transplant outcome. Presence of antibodies to these antigens is detrimental to transplant outcome as it ends up to either acute or chronic humoral rejection depending on the titer of the antibodies to these antigens. However, the role of HLA-DP is not fully clear, predominantly due to lack of adequate publications and the fact that DP antigen and antibody detection became possible with the advent of new beads technology. As a results, allocation system has not yet included HA-DP antibodies in virtual crossmatching. This report presents two novel cases with strong HLA-DP antibodies which resulted in acute humoral rejection (AMR).

Expanding the Envelope: Favorable Outcomes Utilizing Kidneys From Small Pediatric Donors (≤ 15 kg).

BACKGROUND: Utilization of kidneys from small pediatric donors (SPDs ≤ 15 kg) is limited. Decisions to split and use the kidneys for 2 recipients remain controversial. METHODS: Retrospective single-center study aimed primarily at evaluating graft loss within 30 days after transplant using SPD kidneys. Recipients were divided into group A (donor weight < 10 kg, n = 24) and group B (≥ 10 kg, n = 16). RESULTS: Forty transplants were performed with 100% patient survival. Mean follow-up was 402 days, overall graft survival was 95%, with 91.7% and 100% in groups A and B, respectively (P = .24). Mean recipient-to-donor weight ratio (RTDWR) was higher in group A (10.5 vs 6.3, P < .001). Surgical complications were similar between the groups. These were more common with en bloc compared to single implantation (P = .05), and RTDWR was the main predictor (P = .005). Graft function was similar between the groups; mean 12-month creatinine was 1.2 mg % and eGFR was 58.2 mL/min/1.73 m2. Sixteen out of 38 patients developed proteinuria (42%) with no difference among subgroups, although male recipients were at a higher risk (OR = 8.4 [95% CI 1.5-46.1], P = .014); 83% responded to therapy. CONCLUSION: Utilization and early splitting of SPD kidneys yields favorable graft survival and function irrespective of donor weight and age. Early splitting should be considered.

Autoclaved cercarial vaccine against schistosomiasis: ultrastructural and biochemical studies.

Autoclaved cercarial vaccine (ACV) was found to be highly effective in eliciting protective immunity against experimental Schistosomal mansoni. So, the aim of this study was to analyse ACV biochemically and to study ultrastructural changes inflicted on the cercariae as a result of autoclaving, thus rendering it highly protective. Results of this study showed that approximately 100 microg protein and 44 microg carbohydrate were obtained from 10(3) cercariae. The predominant sugar was fucose. Galactose, glucose, manose, galactosamine and glucosamine were also detected. Threonine, glycine, serine and glutamic acid comprised approximately 53.7% of the amino acid residues of the protein. Ultrastructural study revealed preserved architecture of the cercariae. The tails were still attached to the posterior ends of the bodies. However, in others the tails were separated from the bodies and appear schistosomula like. There were also some morphological changes such as thinning of the pericortical envelop with appearance of surface pores.

Synthesis of some new benzothiazole derivatives as potential antimicrobial and antiparasitic agents.

Several thiazolidinonyl benzothiazoles 8a-b and thiazolinylbenzothiazoles 9a-j were synthesized by the reaction of 2-(N-substituted thiocarbamoyl hydrazino) benzothiazoles 7a-d with chloroacetic acid or phenacyl bromide respectively. The intermediate compounds 7a-d were prepared in a good yield by the reaction of 2-hydrazinobenzothiazole (6) with phenylisothiocyanates. Synthesis of hydrazones 10a-c were performed by the reaction of 6 with the corresponding aldehydes. Trials to cyclize the obtained hydrazones 10a-c into the corresponding triazolo derivatives 11a-c were unsuccessful. Addition of 4-morphylino carbonyl chloride to compound 6 yielded the corresponding 2-acid hydrazide derivative 12. Some of the prepared compounds were screened for their anti-parasitic activity. Most of them showed reasonable antinematodal or schistosomicidal activity. In addition, antimicrobial screening of all of the prepared new compounds was performed against Staphylococcus aeurus ATCC 6538, Escherichia coli ATCC 8735 and Candida albicans ATCC 10321 but non of them was active.

Experimental conversion of virulent RH Toxoplasma gondii tachyzoites in vitro.

We aimed to induce conversion of RH-stain tachyzoites to bradyzoites by changing the pH of the culture medium. Alkalization of the medium to pH 8 induced morphological changes in the cultured tachyzoites. The majority of the organism increased in size and changed from a regular crescent shape to a rounded or ovoid shape. Cyst-like structures were formed. Using a computerized image analyser, significant differences in the size of the whole organisms and in their nuclei were observed compared to the control group. The converted organisms also showed significant differences from the control group by quantitative DNA analysis, and did not infect mice.

Autoclaved cercarial vaccine: a new hope against schistosomiasis parasitologic, histopathologic and immunologic studies.

The efficacy of autoclaved cercarial vaccine (ACV) in eliciting protective immunity against Schistosoma mansoni infection was investigated in Swiss strain Albino mice. Two main groups of animals were used. One served as control group and the second was vaccinated with ACV mixed with Bacille Clamette-Guerin (BCG) as an adjuvant, in a single, double and triple doses 2 weeks apart. Six weeks after the first vaccination, all animals were challenged with freshly liberated cercariae of Schistosoma mansoni then sacrificed 7 weeks later. Parasitological, histopathological and immunological studies showed promising results which gave hope in evolution of anti-schistosomal vaccine.

Isolation of dust mites from houses of Egyptian allergic patients and induction of experimental sensitivity by Dermatophagoides pteronyssinus.

Six house dust mite (HDM) species were isolated from dust of floors and mattresses of allergic patients houses in Alexandria. Dermatophagoides pteronyssinus (D.p.) was the dominant species in dust of floors and mattresses with average percentages of 68.9% and 78.3% respectively. It was used to induce experimental sensitivity in Swiss albino mice by repeated weekly intranasal instillation of D.p. mites in phosphate buffer saline (PBS). Cytological examination of bronchoalveolar lavage (BAL) fluid of mice revealed prolonged eosinophilia, that peaked on day 28 of the experiment and persisted till the end of the study. Blood eosinophilic counts were progressively increased during the course of the experiment. Histopathological findings showed evident eosinophilic infiltration in nasal and lung tissues of the sensitized mice. Specific IgE response to D.p. was progressively increased, reaching 30 times higher than the control group on day 42. The detected levels of interluekin-4 (IL-4) were in accordance with immunoglobulin response. D.p. provoked severe allergic response and this may help to design an effective therapy to ameliorate such allergic diseases.

Effect of mebendazole and ivermectin in experimental hepatic capillariasis: parasitological, scanning electron microscopy and immunological studies.

In this study, mebendazole and ivermectin were tried during three different phases of C. hepatica infection. At an early phase, when immature forms were present both drugs were effective in causing destruction and degeneration of the larvae, thus preventing subsequent growth and maturation and consequently the complete absence of eggs. During the second phase, which is found to be the most critical period the two drugs used led to degeneration and resorption of most of adult worms. In the third phase both mebendazole and ivermectin were effective in decreasing the mean number of eggs. After treatment the topographic changes were in the form of disorganized cuticle of the worms and absence of surface uniformity. Such a disorganized cuticle is vulnerable to be attacked. C. hepatica eggs showed irregularities and longitudinal grooves indicated shrinkage of the shell. The effect of the two drugs indicate that both of them were effective in the treatment of hepatic capillariasis.

Experimental amoebic liver abcess produced by oral administration of Entamoeba histolytica cysts.

To determine the possibility of amoebic invasion and liver-abscess formation Swiss albino mice were infected orally with E. histolytica cysts isolated from human stools. Parasitological and histopathological changes in mice colon and liver tissues were sequentially followed. Three weeks postinfection (p.i) 5% of immunocompetent and all cortisonized immunosuppressed mice passed the parasite in their stools. Only 70% of the latter group of mice sacrificed at that time developed invasive intestinal amoebiasis. At the end of the experiment (12 weeks p.i.) 100% of the remaining immunosuppressed animals developed the same intestinal pathology. Amoebic liver abscess was detected in 62.5% of them. Oral inoculation of E. histolytica cysts constitutes an easy highly reproducible procedure for inducing liver abscess in immunosuppressed mice.

Effect of mebendazole and ivermectin in experimental hepatic capillariasis B: histopathological and ultrastructural studies.

Although, rodents are the principle hosts of C. hepatica both true and spurious human infections have been reported. Over half of the reported cases, resulted in death with hepatic capillariasis being discovered at autopsy; even in cases which the infection was detected at laparotomy or liver biopsy, the patient died due to the lack of suitable treatment. Therefore, studies on experimental C. hepatica in mice were carried out on the way of reaching a full program for treatment. The drugs used were mebendazole and ivermectin. The alterations noted in the egg shell by TEM suggest the effectiveness of the drugs used, the eggs appeared to be deformed; the outer shell was broken and distorted in several places. Many pillars were fragmented. The inner layer was also affected, where it showed destruction of its outer lamellae. Ultrastructural changes in the liver cells showed dysplastic changes. It may be a sequelae of mechanical injury or direct antigenic insult of the parasite or their toxins on the liver cells. During the course of the present work, it was noticed that most of the granulomata were in the fibrotic stage denoting acceleration in the process of healing of the lesions and no freshly deposited ova and hence no active cellular granuloma.

Experimental conversion of virulent RH Toxoplasma gondii tachyzoites in vitro

We aimed to induce conversion of RH-stain tachyzoites to bradyzoites by changing the pH of the culture medium. Alkalization of the medium to pH 8 induced morphological changes in the cultured tachyzoites. The majority of the organism increased in size and changed from a regular crescent shape to a rounded or ovoid shape. Cyst-like structures were formed. Using a computerized image analyser, significant differences in the size of the whole organisms and in their nuclei were observed compared to the control group. The converted organisms also showed significant differences from the control group by quantitative DNA analysis, and did not infect mice