Missense mutation in exon 7 of the common gamma chain gene causes a moderate form of X-linked combined immunodeficiency.

Clinical and immunologic features of a recently recognized X-linked combined immunodeficiency disease (XCID) suggested that XCID and X-linked severe combined immunodeficiency (XSCID) might arise from different genetic defects. The recent discovery of mutations in the common gamma chain (gamma c) gene, a constituent of several cytokine receptors, in XSCID provided an opportunity to test directly whether a previously unrecognized mutation in this same gene was responsible for XCID. The status of X chromosome inactivation in blood leukocytes from obligate carriers of XCID was determined from the polymorphic, short tandem repeats (CAG), in the androgen receptor gene, which also contains a methylation-sensitive HpaII site. As in XSCID, X-chromosome inactivation in obligate carriers of XCID was nonrandom in T and B lymphocytes. In addition, X chromosome inactivation in PMNs was variable. Findings from this analysis prompted sequencing of the gamma c gene in this pedigree. A missense mutation in the region coding for the cytoplasmic portion of the gamma c gene was found in three affected males but not in a normal brother. Therefore, this point mutation in the gamma c gene leads to a less severe degree of deficiency in cellular and humoral immunity than that seen in XSCID.     

Frequent ongoing T-cell receptor rearrangements in childhood B- precursor acute lymphoblastic leukemia: implications for monitoring minimal residual disease

Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.     

Whole-body and segmental bioelectrical-impedance analysis in patients with cirrhosis of the liver: changes after treatment of ascites.

Bioelectrical impedance analysis (BIA) is a simple technique for determining body water and calculating body composition. It has been validated in healthy control subjects but not in patients with liver disease. We examined the ability of BIA to detect changes in total body water (TBW) due to removal of ascites. In 12 cirrhotic patients, BIA of the whole body and of body segments was performed before and after treatment of ascites with paracentesis (n = 12) and diuretics (n = 2). TBW changes predicted by BIA, by using two prediction equations, were significantly less than body weight changes (51% and 45% of the weight loss). BIA of body segments showed highly significant changes in both the trunk and the leg and small changes in the arm. These data indicate that BIA of the whole body is not a suitable technique for monitoring fluid changes in cirrhotic patients with ascites. Changes in BIA of body segments may be due to mobilization of edema after the removal of ascites.     

The Parallel Process in Clinical Supervision With a Schizophrenic Client

The authors analyze a male nurse's account of how he experienced his interaction with a female schizophrenic client during sessions of systematic clinical supervision. Notes taken during 15 sessions were analyzed by means of open coding. The analysis revealed the importance of being aware of the parallel process that occurs among the client, the primary nurse, and the unit staff.     

Relation of 5'-nucleotidase and phosphatase activities with immunophenotype, drug resistance and clinical prognosis in childhood leukemia.

Ecto-5'-nucleotidase (ecto-5'NT) catalyzes the extracellular dephosphorylation of nucleotides like IMP. Cytoplasmic 5'NT (cyto-5'NT) and non-specific (e.g. acid- and alkaline) phosphatases (AP) regulate the intracellular degradation of nucleotides. High NT and AP activities might cause a resistance to the thiopurines 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG). We studied the relation between these enzymes and immunophenotype, drug resistance and prognosis in 77 children with acute lymphoblastic leukemia (ALL). Enzyme activities were assessed radiochemically; in vitro drug resistance was measured with the MTT assay. AP activities were higher in T-ALL and B-ALL than in precursor B-ALL. Cyto-5'NT activity was very low in all phenotypes and accounted for a significant proportion of total IMPase activity only in the very immature CD10- c mu- precursor B-ALL. CD10+ ALL cases with high ecto-5'NT activities showed a trend (p = 0.065) for a lower probability of continuous complete remission than those with a low activity. Ecto-5'NT activity was not related to in vitro drug resistance to 6-TG. A weak correlation was found between in vitro 6-TG resistance and cyto-5'NT and AP activities. We conclude that high ecto-5'NT activities do not cause a resistance to 6-thiopurines in childhood ALL. Some patients have high cyto-5'NT and AP activities associated with 6-thiopurine resistance.     

The accumulation of copper by microvillar vesicles isolated from human placenta.

Copper uptake from copper-dihistidine complexes by microvillar vesicles from human placenta was studied. Uptake occurred in two phases: a rapid initial binding followed by approximately linear uptake to equilibrium at approximately 5 min. The uptake showed temperature dependence, was saturable (apparent Vmax 10.5 +/- 1.6 nmol/(mg protein.4 min), apparent Km of 0.6 +/- 0.12 mumol/L) and decreased with increasing osmotic pressure, showing that the Cu uptake arose from accumulation within the vesicles and not from extravesicular binding or isotope exchange. Ceruloplasmin blocked uptake of 64Cu from 64Cu-dihistidine by the vesicles, with 50% inhibition achieved at a protein concentration of 5-10 mumol/L and a 64Cu-dihistidine concentration of 1.5 mumol/L. The effect was specific, because glucose oxidase, a noncopper protein, increased apparent uptake by binding copper and in turn being bound to the nitrocellulose membranes used to separate vesicles from incubation medium. Adding increasing concentrations of histidine also decreased uptake. The data presented indicate that the placenta can accumulate copper from copper-dihistidine, that ceruloplasmin can interfere with uptake and that this system will be very valuable in elucidating the first stage in transfer of copper across the placenta.     

MANAGEMENT OF SEMINOMA OF THE TESTIS: RECOMMENDATIONS BASED ON TREATMENT RESULTS

Background : The results of management of seminoma of the testis at the Department of Radiation Oncology St Vincent's Hospital, Sydney were evaluated retrospectively to: (i) establish that outcomes were in keeping with published results from centres in Australia and overseas; (ii) assess the impact of chemotherapy on management; and (iii) to determine ‘best practice’ management protocols based on our results and a review of the relevant literature. Methods : (i) Assessment of treatment results for stage I and II seminoma of the testis treated by post-orchidectomy radiotherapy and/or chemotherapy at St Vincent's Hospital between 1979 and 1993; (ii) literature review of published data from Australian and overseas centres on the management of seminoma of the testis, and in particular the use of surveillance or chemotherapy either alone, at time of relapse or combined with radiotherapy; and (iii) development of recommendations for use as management protocols in our department. Results : Our data and a review of the literature suggest that post-orchidectomy radiotherapy with chemotherapy for relapse in stage I and IIA disease results in long-term cure rates approaching 100%. Treatment with chemotherapy either routinely or selectively or using a surveillance policy is unlikely to show any improvement in outcome and may be less cost-effective and/or produce increased morbidity and the risk of secondary leukaemia. For stage IIB disease (5–10 cm) the use of initial combination chemotherapy with or without subsequent radiotherapy did not appear to give better outcomes than initial radical radiotherapy alone, reserving chemotherapy or further radiotherapy for relapse. For bulkier stage IIB disease (> 10cm). the use of initial chemotherapy plus consolidation radiotherapy appeared to be an appropriate treatment. Conclusions : Management protocols for seminoma of the testis at St Vincent's Hospital, Sydney Department of Radiation Oncology currently are (i) stage I, IA and IIB (5–10 cm): post-orchidectomy radiotherapy alone with chemotherapy or further radiotherapy for relapse; and (ii) stage IIB (> 10 cm) disease: initial chemotherapy post-orchidectomy followed by radiotherapy to sites of initial disease involvement.     

Anti-mitochondrial antibodies in patients with dilated cardiomyopathy (anti-M7) are directed against flavoenzymes with covalently bound FAD

Anti-mitochondrial antibodies (anti-M7) in sera from patients with dilated cardiomyopathy and myocarditis recognize, besides mitochondrial antigens, bacterial sarcosine dehydrogenase. The common target antigen was identified as the covalently bound FAD of mitochondrial and bacterial flavoenzymes. Thus, anti-M7-positive serum reacted on Western blots exclusively with covalently flavinylated enzymes. The antigenic specificity of anti-M7 sera was reproduced by an antiserum raised in rabbits with 6-hydroxy- D -nicotine oxidase. The heart mitochondrial membrane antigen recognized by anti-M7 serum was identified as the flavoprotein subunit of succinate dehydrogenase, the antigens in rat liver mitochondrial matrix as the flavoenzymes dimethylglycine dehydrogenase and sarcosine dehydrogenase. Anti-M7 serum contained a specific anti-flavoenzyme antibody fraction. Nanomolar concentrations of FAD and riboflavin inhibited the immune reaction on Western blots and in ELISA, and incubation with FAD-agarose depleted the anti-M7 activity of the serum. N-terminally deleted dimethylglycine dehydrogenase proteins were only immunoprecipitated by anti-M7 sera when the FAD was covalently incorporated. An affinity constant (K_D) of 10^?8 M was established for the anti-flavoenzyme antibodies by competitive ELISA. Of patients with cardiomyopathy and myocarditis, 36% and 25%, respectively, were anti-flavoenzyme-positive by Western blot and ELISA, but only two of 15 patients with other heart diseases and none of 50 healthy controls.     

Practices of reading and writing: the constitutive role of the patient record in medical work

This paper contributes to a reappraisal of the sociological significance of the medical record. Building upon re-evaluations of the notion of ‘representation’ in ethnomethodological and science and technology studies, it attempts to portray the medical record as an artefact which mediates the social relations that act and work through it. Through practices of reading and writing, it is argued, the medical record figures as a fundamental, constitutive element of medical practice. To address some of the dimensions that are involved, three case fragments are discussed. The way the medical record enters into the process of ‘medical decision making’ in the doctor-patient interaction, and into that interaction itself, is discussed first. Subsequently, some aspects of how the record mediates medical work as it is performed in the wards of a hospital are outlined. A third instance of its prominent role demonstrates how practices of reading and writing tend to produce particular renderings of patients’ histories - including notions of how medical work is structured.     

Molecular biological and immunohistochemical analysis of tp53 in human ameloblastomas]

AIM: Ameloblastoma is the most frequent epithelial tumor of the jaws. The spread is locally invasive and it tends to recur. Malignant transformation and occurrence of metastases has been described. Immunohistochemical analysis shows an enhanced expression of P53 protein in ameloblastomas. Mutation of the tp53 tumor suppressor gene was verified in several human tumors. In this study histological sections were analyzed for the expression of P53 protein and the tp53 gene was examined for mutations. MATERIAL AND METHODS: Tumor DNA from 29 patients with an ameloblastoma was examined for mutations in exons 5 to 8 of the tp53 tumor suppressor gene using PCR, SSCP,- and sequential analysis. Histological sections of the tumors were analyzed immunohistochemically for an overexpression of P53 protein. RESULTS: Two tp53 mutations (6.9%) in ameloblastomas were verified for the first time. In all 58.6% of the tumors showed an immunoreactivity for P53 protein. There was a statistically significant positive correlation (Fisher's exact test p<0.0148) between an increased number of P53-positive tumor cells and the appearance of recurrence. DISCUSSION: In the face of the uncertain postoperative behavior of ameloblastomas, the immunohistochemical verification of more than 10% P53-positive tumor cells may give a prognostic indication for a tendency to recurrence.