Fatality due to paraquat intoxication: confirmation by postmortem tissue analysis

A brief case report is presented describing a patient who unknowingly ingested a fatal amount of paraquat, presumably mixed in some illicit moonshine alcohol. Despite an initial clinical presentation typical of paraquat intoxication, the herbicide was absent upon analysis of multiple urine and blood specimens, and the diagnosis was confirmed only postmortem after determination of high paraquat tissue concentrations in all the major organs. Autopsy results are presented along with a discussion of the histopathologic changes observed in the lungs, liver, and kidneys. Because the combination of toxicologic sequelae attributable to acute paraquat poisoning is fairly unique to this agent, the diagnosis must be suspected highly early in the clinical course of such cases and appropriate therapy initiated, despite the inability to isolate paraquat on preliminary laboratory screening.     

The MMPI as a predictor of response to conservative treatment for low back pain.

Studies that used the MMPI to predict the response of chronic low back pain patients to standard medical treatment have not produced definitive results. Patients seen in a university hospital orthopedic back pain clinic were given the MMPI before treatment, and 6 to 12 months later 76 patients completed follow-up forms that indicated their level of intensity during the previous week and their ratings of the success of treatment in relieving their pain as well as in enabling them to return to normal activities. Predictions of poor response were made in terms of either single MMPI scales or code types. Patients with poor outcome on two of the three criteria (level of pain intensity and ability to return to normal activities) had significantly higher scores on the Hs scale. The predicted high risk code types very accurately identified patients with poor response on the same two criteria; however, the code-type procedure overpredicted poor response in the good outcome group.     

Development and Evaluation of a Tetraplex Flow Cytometric Assay for Quantitation of Serum Antibodies to Neisseria meningitidis Serogroups A, C, Y, and W-135

A rapid and simple method for the simultaneous quantitation of serum immunoglobulin G (IgG) antibodies specific for Neisseria meningitidis serogroups A, C, Y, and W-135 was developed and evaluated. Four bead sets were generated, each conjugated with one of the meningococcal capsular polysaccharides (A, C, Y, or W-135) and serologically assessed by the use of antimeningococcal international reference sera. Cross-reactivity studies demonstrated no inhibition between monoplex and multiplex assays, and the assay was linear over a 24-fold serum dilution range. Inhibition studies demonstrated that the assay is specific, with <25% heterologous inhibition occurring. The assay was also found to have low intra- and interassay variations and limits of detection ≤650 pg/ml. A comparison of the meningococcal bead assay with the standardized meningococcal enzyme-linked immunosorbent assay showed a good correlation between the IgG concentrations obtained by each assay. The tetraplex assay has the potential to be an important addition to the serologic evaluation of meningococcal capsular polysaccharide conjugate vaccines.     

Distribution of actin and myosin in a rat neuronal cell line infected with herpes simplex virus

Summary The indirect immunofluorescence technique was used to study alterations in the distribution of actin and myosin filaments in a rat B 103 neuronal cell line infected with herpes simplex virus type 1 (HSV-1). In uninfected cells, actin filaments were arranged in parallel and ran lengthwise from one end of the cell to the other; although myosin filaments were closely associated with actin filaments, additional myosin formed a netlike distribution which did not stain for actin. In infected cells, actin filaments became more randomly aligned and were concentrated along with myosin in close association with rosette-like formations of nuclei in syncytial cells; structural organization of actin and myosin within these intensely staining areas was no longer evident. The possible role of contractile proteins (actin and myosin) in viral infections of neural tissue is raised.With 3 Figures     

Identification of coagulase-negative staphylococci with the API staph system.

A kit for the identification of staphylococci based on the biochemical criteria proposed by Kloos and Schleifer (W.E. Kloos and K.H. Schleifer, J. Clin. Microbiol., 1:82-88, 1975) is now available commercially. The system was used to identify 100 strains of coagulase-negative staphylococci isolated from various body sites as the primary etiological agent of clinical infection. The increasing importance of staphylococci and their resistance to antibiotics provided the rationale for such an investigation. Over 90% of the Staphylococcus isolates were easily identified as to their species on the basis of their reaction profile to 19 biochemical tests included in the kit. The remainder, which showed minor variations, could also be assigned to the various species. Identification of the isolates was as follows: S. epidermidis, 54; S. haemolyticus, 5; S. simulans, 2; S. hominis, 1; S. capitis, 4; S. cohnii, 2; S. warneri, 2; S. xylosus, 8; and S. saprophyticus, 22. Antibiotic sensitivity patterns were determined for each of the isolates. Novobiocin resistance was detected in strains of S. saprophyticus and S. xylosus, a property hitherto recognized in Micrococcus sp. type 3 causing bacteriuria in young women. Resistance to penicillin was widespread among strains of several species, whereas resistance to tetracycline was mainly confined to strains of S. epidermidis. General resistance to sulfamethoxazole and nalidixic acid was found among all strains, with almost uniform sensitivity to the other drugs tested.     

An evaluation of commercial radioisotope methods for the determination of folate and vitamin B12.

Five commercial kits for the determination of folate and six kits for the determination of vitamin B12 were investigated. Their performance has been compared with microbiological methods for the two vitamins and with a non-commercial radioisotopic method for B12. The results show the importance of the determination of the reference range for an individual laboratory for each method. The precision of the kits varied appreciably, as did their performance using specimens from patients with different haematological disorders. In particular, certain kits failed to detect all patients with pernicious anaemia. The relative accuracy of the kits was assessed. Various factors which should be taken into account in the final selection of a satisfactory kit are discussed.     

Differential infiltration by CD45RO and CD45RA subsets of T cells associated with human heart allograft rejection.

Subsets of T cells express different isoforms of the leukocyte common antigen CD45; those expressing the glycoprotein 220 isoform (CD45RA) have been characterized as naive in their response to antigens, and those expressing the glycoprotein 180 isoform (CD45RO) as memory T cells. The association between the rejection status of human cardiac allograft recipients and the relative infiltration of the CD45 subsets of both CD8+ and CD4+ T cells was examined using two-color immunohistological labeling techniques on 33 heart transplant biopsies, categorized by routine histological and clinical criteria as mild (requiring no treatment) or moderate (requiring antirejection therapy) rejection. Double-labeling was performed using pairs of monoclonal antibodies to define the following populations: CD4+ CD45RA+, CD4+ CD45RO+, CD8+ CD45RA+, and CD8+-CD45RO+. The number of cells per high-power field (HPF) for each of these cell subsets was counted in every biopsy. In cases with mild rejection, infiltration was predominant for CD4+ CD45RA+ cells (median = 5.0 cells/HPF) relative to CD4+ CD45RO+ (3.12 cells/HPF), CD8+ CD45RA+ (2.14 cells/HPF), and especially CD8+ CD45RO+ (1.22 cells/HPF) populations. In cases with moderate rejection, all four subpopulations increased but were essentially equivalent in intensity, such that in comparison to cases with mild rejection, the smallest increase was seen for CD4+ CD45RA+ cells (6.67 cells/HPF, P < 0.09) and the greatest for CD8+ CD45RO+ cells (7.00 cells/HPF, P < 0.002). A majority of CD8 cells expressed CD45RA in 14 of 16 (88%) cases of mild rejection compared to only 2 of 17 cases of moderate rejection. Moreover, the ratio of CD45RO+ to CD45RA+ cells in each biopsy was higher in moderate versus mild rejection for both CD4 (median ratios = 1.13 versus 0.68, respectively; P < 0.008) and CD8 (1.43 versus 0.58, respectively; P < 0.005) subsets. A majority of T cells expressed CD45RO in cases of moderate rejection (11 of 14 or 79%), compared to only 1 of 13 (8%) cases of mild rejection. These findings indicate that during generally self-limited mild acute cardiac allograft rejection there is a predominance of naive CD45RA+ T cells, especially of the CD4 phenotype, whereas during moderate rejection there is a significant shift toward activated CD45RO+ T cells, especially in the CD8 population.     

Oestrogen receptors in colorectal carcinoma.

The oestrogen receptor content of colorectal adenocarcinoma was investigated using an established ligand binding biochemical assay and two more recently introduced techniques using specific monoclonal antibodies (Abbott ER-EIA and ER-ICA assay kits). Twenty nine tumours were investigated by the ligand binding assay. Only one (3.4%) tumour gave a weakly positive result (11 fmol/mg cytosol protein); the rest were all negative. Where sufficient tissue was available, the receptors were also determined by a quantitative immunoassay in 18 patients and an immunohistochemical method in 13 patients. The results were similarly all negative. It is concluded that most colorectal carcinomas, irrespective of sex, are oestrogen receptor negative, and it is thus unlikely that hormonal manipulation would have an influence on the course of the disease.     

Intrinsic factor antibody tests.

The sensitivity of methods to detect antibodies to intrinsic factor was assessed. Five sera of known antibody content were tested in 31 laboratories and 30 sera from patients with pernicious anaemia were tested in one laboratory. Five non-commercial methods and two kits for type I antibodies and one non-commercial method for types I and II antibodies are in current use. Differences in sensitivity of the non-commercial methods for type I antibodies related more to the antigen: antibody ratio in the test system than to the method itself. A radioimmune assay for types I and II antibodies showed the best sensitivity but that of an enzyme linked immunosorbent assay (ELISA) method was poor.