Induction of long-term heart allograft survival in the rat by rabbit ATG

A rat model for induction of transplantation tolerance, by antithymocyte globulin (ATG) as sole immunosuppressive agent, was studied. Vascularized heart allografts were employed. The conditions for establishment of long-term surviving (LTS) grafts were investigated as well as some of the characteristics of the tolerant state. The tolerance-inducing effect of ATG was found to be reproducible and dose-dependent. Treatment before grafting was essential. Preimmunization of the recipient inhibited the tolerance induction, while thymectomy seemed to have the opposite effect. The differences in survival of second allografts, third party or syngeneic to the first, indicated a largely strain-specific tolerance that most probably was the result of a changed host reactivity and for its induction strictly depended on presence of the graft. There were microscopical signs of rejection in the LTS grafts, while almost no such changes could be found in second allografts from the same donor strain, transplanted to the LTS-bearing recipients.     

Familial occurrence of lumbar spondylolysis and spondylolisthesis

In a Finnish kindred consisting of 192 descendants from two marriages of a male ancestor born in 1868, the lumbar spines of 105 of the 170 living members were X-rayed. Spondylolysis was found in 22 individuals. In addition, six of them had spondylolisthesis, four had spina bifida occulta, and two had a transitional lumbar/sacral vertebra. Seven members of the kindred without spondylolysis had spina bifida occulta and 10 had transitional lumbar vertebrae.
The pedigree is consistent with autosomal dominant inheritance and incomplete (about 75 %) penetrance for spondylolysis. It raises the question of a common aetiology for several congenital disturbances in the formation of lumbar vertebrae and possibly supports the concept of a variable expressivity of a "spondylolysis gene".     

Development of host plasma cells during graft-versus-host reactions in mice

Graft-versus-host (GVH) reactions induced by thymus or spleen cells in newborn mice were found to trigger the development of plasma cells in the medullary areas of lymph nodes. No germinal centers were found. The plasma cells were found from the fourth day of the GVH reactions and increased in numbers over the next few days. On the 14th day the plasma cells were still present, although in lower numbers. Results of immunodiffusion experiments indicated that during GVH reactions induced by spleen cells, donor as well as host plasma cells develop. In contrast, induction of GVH reactions by thymus cells leads to the development of plasma cells, which probably originate exclusively from the host. Positive Coombs' reactions were detected 15–20 days after induction of GVH reactions and host immunoglobulins were found to contribute to the Coombs' positivity. The GVH reactions stimulated the formation of antibodies to sheep erythrocytes. This effect was more marked on 7 S than on 19 S antibody production.     

Mucosal FOXP3-expressing CD4+ CD25high regulatory T cells in Helicobacter pylori-infected patients

Helicobacter pylori chronically colonizes the stomach and duodenum and causes peptic ulcers or gastric adenocarcinoma in 10 to 20% of infected individuals. We hypothesize that the inability of patients to clear H. pylori infections is a consequence of active suppression of the immune response. Here we show that H. pylori-infected individuals have increased frequencies of CD4(+) CD25(high) T cells in both the stomach and duodenal mucosa compared to uninfected controls. These cells have the phenotype of regulatory T cells, as they express FOXP3, a key gene for the development and function of regulatory T cells, as well as high levels of the cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) protein. In contrast, mucosal CD4(+) CD25(low) and CD4(+) CD25(-) cells express little FOXP3 mRNA and low levels of the CTLA-4 protein. Mucosal CD4(+) CD25(high) T cells are present in individuals with asymptomatic H. pylori infections as well as in duodenal ulcer patients. The frequencies of CD4(+) CD25(high) cells are also increased in the stomachs of H. pylori-infected patients with gastric adenocarcinoma, particularly in cancer-affected tissues. These findings suggest that regulatory T cells may suppress mucosal immune responses and thereby contribute to the persistence of H. pylori infections.     

Agglutinate formation in serum samples mixed with intravenous fat emulsions

The degree of fat agglutination (the so-called "creaming phenomenon") was measured in sera from 51 critically ill patients, 200 ambulatory patients and 24 healthy volunteers. A 400-microliter serum sample was mixed with 10 microliter of a fat emulsion (Intralipid), incubated at 37 degrees C, and examined after 2, 6, and 24 h. Almost all samples from critically ill patients exhibited creaming, as did 31% of the samples from ambulatory patients. Serum samples from healthy volunteers were incubated with purified C-reactive protein (CRP). At a CRP concentration of 40 mg/L, creaming was always observed. Creaming also occurred at normal serum levels of CRP, but at increased concentrations of other serum proteins. Finally, the creaming test was performed with 12 different fat emulsions, mixed with sera from critically ill and healthy subjects. Healthy sera produced no creaming and sera from critically ill patients invariably showed creaming with every emulsion.     

Neonatal effects of adding epidural fentanyl to 0.5% bupivacaine for caesarean section

Epidural injection of opioids has been introduced to improve analgesia during labour and caesarean section. This study was designed to quantify placental transfer of fentanyl and to evaluate neonatal effects of adding fentanyl to 0.5% bupivacaine for epidural anaesthesia in women undergoing elective caesarean section at term. The parturients were randomly allocated to one of four groups of 20, who received either saline (control) or 50, 75 or 100 microg of fentanyl added to 20 ml of 0.5% bupivacaine. Apgar scores, time to sustained respiration and umbilical acid-base values did not differ among the groups. The median (interquartile range) umbilical artery to maternal vein fentanyl concentration ratio was 0.34 (0.26-0.48) when the fentanyl groups were taken together. Neurologic and adaptive capacity scores were evaluated at 2 and 24 h. Neonates whose mothers received fentanyl had lower scores with regard to supporting reaction at 2 h and active tone at 24 h, when compared to controls (P<0.05), but there were no differences among the groups with regard to the other test criteria in the neurobehavioural test. In conclusion, epidural injection of fentanyl 50-100 microg did not produce depression of the term neonate.     

p53 overexpression in normal and dysplastic tissues adjacent to p53 negative squamous cell carcinomas of the head and neck

p53 overexpression was present in the normal or dysplastic epithelium, but absent in the adjacent invasive cancers of five patients with head and neck squamous cell carcinomas (HNSCC), when p53 immunostaining (IHC) was performed. In three of the five p53 immunoreactive dysplasias and adjacent p53 negative invasive cancers single stranded conformation polymorphism (SSCP) results from exon 7 and 8 were also obtained. Bandshifts in exon 7 were detected in two dysplasias, and bandshifts in exon 8 were found in a third. Sequencing of exon 7 in the first dysplasia with bandshift indicated a deletion of codon 241-242 (loss of CT) resulting in a frame shift. In the second dysplasia with bandshift a mutation was observed in codon 244 resulting in a Gly-->Arg substitution in the protein sequence. In the adjacent IHC p53 negative invasive cancer lesions, no bandshifts could be observed by SSCP, and sequencing did not reveal any mutated p53. WAF1/p21 (IHC) expression was assayed to study p53 function. Image cytometry (ICM) DNA analysis, estimating genetic instability, showed progress in DNA aberration for invasive cancer lesions as compared with the dysplasias. Human papillomavirus (HPV DNA) was not detected by a polymerase chain reaction (PCR) in any of the five cancers thus excluding possible p53 degradation caused by HPV protein. In conclusion, the finding of p53 mutations in mild, moderate, and severe dysplasia indicates that p53 mutation, not only p53 immunoreactivity, can be an early event in HNSCC carcinogenesis. The lack of p53 immunoreactivity in the invasive cancers adjacent to p53 positive dysplasias could possibly be attributed to loss of the mutant allele, or clonal heterogeneity.