The onset of nephritis in the (NZB x SWR)F1 murine model for systemic lupus erythematosus correlates with an increase in the ratio of CD4 to CD8 T lymphocytes specific for the nephritogenic idiotype (IdLNF1).

An idiotypically related family of nephritogenic antibodies (IdLNF1) has been shown to be important in the pathogenesis of autoimmune glomerulonephritis in the (NZB x SWR)F1 hybrid, SNF1. Idiotype-specific T lymphocytes which modulate expression of antibody bearing that idiotype may be important in the pathogenesis of systemic lupus erythematosus (SLE). Here, IdLNF1-reactive T lymphocytes were not only found to be present in the NZB, SWR, and SNF1, but a significantly (P < or = 0.05) greater number of IdLNF1-reactive Thy 1.2+ splenic lymphocytes were observed as early as 12 weeks of age in the SNF1. Further, a significant shift in the ratio of CD4+ to CD8+ IdLNF1-reactive T lymphocytes in favor of CD4+ IdLNF1-reactive T cells was observed at 20 to 24 weeks of age only in the SNF1. This shift correlated with an increase in IdLNF1+IgG, and deposition of IdLNF1 bearing immunoglobulin in the kidney glomeruli. These observations suggest a role for idiotype-specific T lymphocytes in the induction of glomerulonephritis in this murine model of SLE.     

Lack of Effect of Olanzapine on the Pharmacokinetics of a Single Aminophylline Dose in Healthy Men

Study Objective . To test whether olanzapine, an atypical antipsychotic, is an inhibitor of cytochrome P450 (CYP) 1A2 activity, we conducted a drug interaction study with theophylline, a known CYP1A2 substrate. Design . Two-way, randomized, crossover study. Setting . Clinical research laboratory. Subjects . Nineteen healthy males (16 smokers, 3 nonsmokers). Interventions . Because the a priori expectation was no effect of olanzapine on theophylline pharmacokinetics, a parallel study using cimetidine was included as a positive control. In group 1, 12 healthy subjects received a 30-minute intravenous infusion of aminophylline 350 mg after 9 consecutive days of either olanzapine or placebo. In group 2, seven healthy subjects received a similar aminophylline infusion after 9 consecutive days of either cimetidine or placebo. Measurements and Main Results . Concentrations of theophylline and its metabolites in serum and urine were measured for 24 and 72 hours, respectively. Plasma concentrations of olanzapine and its metabolites were measured for 24 hours after the next to last dose and 168 hours after the last olanzapine dose. Olanzapine did not affect theophylline pharmacokinetics. However, cimetidine significantly decreased theophylline clearance and the corresponding formation of its metabolites. Urinary excretion of theophylline and its metabolites was unaffected by olanzapine but was reduced significantly by cimetidine. Steady-state concentrations of olanzapine (15.3 ng/ml), 10-N-glucuronide (4.9 ng/ml), and 4′-N-desmethyl olanzapine (2.5 ng/ml) were observed after olanzapine 10 mg once/day and were unaffected by coadministration of theophylline. Conclusion . As predicted by in vitro studies, steady-state concentrations of olanzapine and its metabolites did not affect theophylline pharmacokinetics and should not affect the pharmacokinetics of other agents metabolized by the CYP1A2 isozyme.     

Comparison of indium 111-labeled platelets v leukocytes in a pyogenic abscess

This study sought to determine which blood component, WBCs or platelets, is the more specific indicator of an abscess and where each localizes. An abscess was created using stool in the hind limb of dogs. After 24 hours, one group was given autologous indium 111-labeled platelets and another group was given autologous indium 111-labeled WBCs. Blood, abscess fluid, infected operative control muscle tissue, and nonoperative control muscle tissue were counted for radioactivity 24 hours after administration of the labeled cells. There was significantly (P less than .001) less WBC radioactivity in blood and more within abscess fluid compared with platelets. The highest platelet activity occurred in muscle tissue adjacent to the abscess (P less than .002) compared with platelet activity in abscess fluid or control muscle tissue. The unwanted high platelet blood background activity and the desirable high concentration of WBC radioactivity within the abscess fluid makes the latter the preferential radionuclide imaging agent.     

Immediate esthetic treatment for anterior teeth: report of cases

Prompt restoration of function and esthetic appearance of dentition can avoid psychological stress and functional problems. Surgical procedures that require long-term bone deposition and soft-tissue healing can accompany periodontal and orthodontic reinforcement, but other less invasive, immediate, intermediate, and final treatment plans can be initiated with good results.     

Preparation and evaluation of a 99mTc-SnF2 colloid kit for leukocyte labeling

Stannous fluoride colloid (SFC) kits for instant radiolabeling with 99mTc were prepared and evaluated for suitability as a leukocyte radiolabeling agent. Technetium-99m labeling for kits stored at -15 degrees C for up to 3 mo was greater than 95% as determined by instant thin layer chromatography while colloid particles of 1-3 microns were measured by electron microscope for these preparations. Canine leukocyte preparations labeled with [99mTc]SFC and characterized by triple density gradients of metrizamide in plasma demonstrated an 83% leukocyte association. Analysis of labeled cell preparation for up to 3 hr demonstrated label stability. Labeled leukocytes, when readministered in normal dogs, demonstrated bi-exponential blood clearance with uptake and subsequent clearance from lung. There was increasing uptake of labeled leukocytes by the liver until steady state was achieved. Furthermore, when whole blood samples were analyzed by the triple density gradient method, an increasing monocyte-to-granulocyte ratio was observed to occur with time. By 3 hr 95% of the whole blood activity was associated with the leukocyte fraction. Dogs in which a 24-hr sterile abscess was created demonstrated elevated blood-pool activity as compared to control with localization of the labeled cells at inflammatory sites within 3 hr following cell readministration.     

Akinetic mutism: pharmacologic probe of the dopaminergic mesencephalofrontal activating system

Four children who exhibited akinetic mutism during the course of their neurologic diseases were treated with bromocriptine. Reversal of the akinetic mute states was evident in all patients. Pathways of the dopaminergic neurons are reviewed and a clinically useful mechanism which causes akinetic mutism is postulated.     

Relationships among the histologic pattern, intensity, and phenotypes of T cells infiltrating renal allografts

The evaluation of renal allograft rejection by routine histologic evaluation of transplant biopsy is often a diagnostic problem. Advances in monoclonal antibody and immunohistochemical technology have led to their application in characterizing the phenotype of peripheral blood lymphocytes in transplant recipients, as well as the infiltrating lymphocytes in renal biopsy specimens (both tissue and aspiration cytology samples). Recent reports suggest that the relative number of infiltrating T cells and the T cell phenotypic subset ratio may have some association with graft survival. However, most allograft biopsy studies have not examined the relationship of the intensity and phenotype of T cells to the histologic pattern of infiltration, while fine-needle aspiration cytology (FNAC) and peripheral blood analysis do not allow for this assessment. To examine the association of histologic pattern with the intensity and phenotype of T cell infiltrates, immunoperoxidase labeling of cells using monoclonal antibodies was evaluated in 66 renal allograft biopsies performed because of clinical suspicion of rejection. Our findings indicate that the ratio of T helper-inducer (Leu 3) cells to T suppressor-cytotoxic (Leu 2) cells is significantly lower in the pattern of diffuse renal cortex infiltration (cortical diffuse [CD] pattern) when compared with other histologic patterns (cortical aggregate or perivascular), regardless of the overall intensity of the T cell infiltrate. A significant difference in T cell phenotypes was also found among different histologic patterns as expressed by Leu 3/Leu 2 ratios and by the number of Leu 2 cells. An increase in the overall intensity of T cell infiltrate was not associated with significant changes in T cell phenotype seen in any pattern, but an increase in the intensity of the cortical diffuse T cell infiltrate was associated with a significant decrease in the Leu 3/Leu 2 ratio (P less than 0.04), which was due to an increase in the population of Leu 2 cells (P less than 0.002). Interestingly, increases in the intensity of either cortical aggregate or perivascular T cell infiltrates were associated with significant increases in both Leu 3 and Leu 2 cells, as well as a tendency towards higher Leu 3/Leu 2 ratios. These findings indicate that evaluation of T cell infiltrates by phenotype in renal allografts is dependent upon the pattern as well as the intensity of infiltrate.     

Contraceptive and sterilization practices and extrauterine pregnancy: a realistic perspective.

Comparative data on the incidence of ectopic pregnancy among accidental pregnancies associated with failure of a contraceptive or sterilization procedure are shown in Table 16. The practical clinical significance of the data in this review is predicated upon a number of related factors. One of the most important of these is the realistic failure rate (or success rate) of each contraceptive or sterilization method. The reported efficacy of various contraceptive methods has such a wide range that we have not attempted to calculate the likelihood that a woman may experience an ectopic pregnancy within a particular time period while using a specific method. The success or failure rate of each method is influenced by such variables as (1) the conscientiousness and ability of the patient to follow instructions, (2) the true failure rate of the method itself, (3) the experience of the clinician prescribing a method or performing a surgical procedure, and (4) other factors less clearly defined. Because of these many variables, the data shown in Table 16 were calculated on the basis of the number of reported accidental pregnancies which occurred coincidentally with, or subsequent to, a specific contraceptive or sterilization modality. (formula: see text). These data do not reflect the actual rate of occurrence of ectopic pregnancy with respect to woman-months of experience. We recognize the significant influence that age, race, gravidity, and socioeconomic factors have upon the incidence of ectopic pregnancy, but were unable to control for these factors in the data presented in this review. These data reprresent only what has occurred under specific circumstances and cannot logically be extrapolated to any specific future case or study series. It is important to emphasize the necessity of constant awareness by the medical and paraprofessional personnel of the potentially increased risk to the patient of an extrauterine pregnancy should one or another of these contraceptive or sterilization procedures fail. Complacency or a false sense of security on the part of responsible medical personnel concerning women who are "protected against conception" can quickly lead to a life-threatening situation in case of an ectopic pregnancy. Prompt diagnosis and definitive treatment of the extrauterine pregnancy is vital for the successful management of this serious complication of conception.     

Artifactual focal accumulation of Tc-99m bone imaging tracer in the chest. Technical note (bone imaging artifact)

Four patients undergoing routine bone imaging with a Tc-99m bone imaging agent were observed to have multiple focal areas of increased uptake in the lungs. Delayed or repeat examination demonstrated resolution of the areas. The authors conclude that this was an isolated and bizarre case of aggregate formation.