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Biomedical subjects

A Beishuizen

Publications and source records attributed to A Beishuizen.

At least 19 recordsLinked to original sources

Herpes simplex virus type 1 and respiratory disease in critically-ill patients: Real pathogen or innocent bystander?

Herpes simplex virus type 1 (HSV-1) has been associated with pulmonary disease, mostly in severely immunocompromised patients. After reactivation and shedding in the oropharynx, the virus may reach the lower respiratory tract by aspiration or by contiguous spread. HSV-1 can be detected in clinical specimens by virus culture or quantitatively by nucleic acid amplification techniques. With these techniques, HSV-1 is often detected in the respiratory secretions of critically-ill patients. However, a clear diagnosis of HSV-1 pneumonia is difficult to establish because clinical criteria, radiological features and laboratory findings all lack specificity. Lower respiratory tract HSV-1 infections have not been associated with specific risk-factors. There is also an absence of consistent data concerning the effect of antiviral treatment on the outcome of critically-ill patients. Further studies are needed to better define the pathogenic role of HSV-1 in the lower respiratory tract of these patients, to improve the diagnosis, and, especially, to assess the need for antiviral treatment in the individual patient.

Antiviral Agents↗

[Adjuvant therapies for sepsis and shock: which are more effective?].

Adjuvant therapy for severe sepsis and shock can be divided into 4 groups. The first group comprises those compounds with proven efficacy in human studies (activated protein C and recombinant bacterial permeability-increasing protein). The second group includes compounds with potential efficacy (heparin), while the third group represents those with no demonstrated efficacy in randomised clinical trials (tumour necrosis factor and interleukin-1 antibodies and receptor antagonists). The fourth group includes those drugs which have been found to be potentially effective in animal studies, but which have not yet been evaluated in humans (i.e., tyrosine kinase inhibitors, selective inducible nitric oxide synthase inhibitors, polyadenosine-diphosphate-ribose-polymerase and caspase III (apoptosis) inhibitors). Formal clinical comparisons between the various treatment options are necessary to assist the clinician in selecting the appropriate form of therapy.

Animals↗

Patterns of corticosteroid-binding globulin and the free cortisol index during septic shock and multitrauma.

OBJECTIVE: To study the time course of corticosteroid binding-globulin (CBG) level and the free cortisol index (FCI) in comparison with total cortisol and ACTH concentrations during acute and prolonged critical illness. DESIGN: Prospective observational clinical study. SETTING: Twenty-bed medical/surgical intensive care unit. PATIENTS AND PARTICIPANTS: Thirty patients with septic shock, eight patients with multitrauma, and forty healthy control subjects. MEASUREMENTS AND RESULTS: During 14 days or until discharge/death, we serially measured serum concentrations of CBG, cortisol, TNF-alpha, IL-6, plasma ACTH immunoreactivity, and the FCI (=cortisol/CBG x 100). We also recorded haemodynamic parameters, APACHE II, ISS, SOFA scores, shock duration, inotrope use, and ICU mortality. In both groups we found markedly decreased CBG levels in the early phase (septic shock: 17.5+/-5.9, and trauma: 16.1+/-2.3 mg/l) in comparison with controls (37.3+/-5.3 mg/l). The FCI was high in this early phase (septic shock: 7.2+/-2.7; trauma: 6.5+/-1.3; controls: 1.25+/-0.76). During follow-up, CBG levels significantly increased, reaching normal levels from day 7 on. The FCI showed an opposite biphasic pattern, with near-normalising FCI values during the second phase. Regression analysis showed a negative correlation between CBG and IL-6 levels (rs=-0.63; P<0.05), but no relation between CBG concentrations and disease severity, shock duration or death was found. CONCLUSIONS: We found extremely low CBG levels in early stage septic shock and multitrauma. These dramatic changes are reflected in a concomitant higher FCI, indicating a higher free cortisol level. A second phase displays increasing and normalising CBG levels, independent from clinical parameters. We believe that CBG plays an active role in the glucocorticoid response to severe stress and in the regulation of cortisol availability to target tissues.

APACHE↗

The hypothalamic-pituitary-adrenal response to critical illness.

The maintenance of life depends on the capacity of the organism to sustain its equilibrium via allostasis'-the ability to achieve stability through change. Life-threatening disease induces acute adaptive responses specific to the stimulus and generalized responses when the disturbances are prolonged. These changes are associated with increased activity of the hypothalamic-pituitary-adrenal axis and may have survival value in preparing the body for fight or flight'. There is a shift towards an increase in glucocorticoid production and away from mineralocorticoid and androgen production, as well as an increase in the biological effects of glucocorticoids through an increased cortisol free fraction and an increased glucocorticoid receptor sensitivity. During the prolonged phase, there is a dissociation between high plasma cortisol and low adrenocorticotropin hormone levels, suggesting non-adrenocorticotropin hormone-mediated mechanisms for the regulation of the adrenal cortex. This hypercortisolism is in contrast to the very low dehydroepiandrosterone sulphate level, indicating an imbalance between the immunostimulatory and immunosuppressive adrenocortical hormones. The question is whether the total serum cortisol concentration represents sufficient glucocorticoid biological activity during the prolonged phase of critical illness.

Animals↗

Relative adrenal failure in intensive care: an identifiable problem requiring treatment?

Adequate adrenocortical function is essential to survive critical illness. Most critically ill patients display an elevated plasma cortisol level, reflecting activation of the pituitary-adrenal axis, which is considered to be a homeostatic adaptation. In the setting of critical illness, the failure of an appropriate neuroendocrine response can lead to the picture of vasopressor-dependent refractory hypotension. This state of relative or functional adrenal insufficiency is characterized by an inadequate production of cortisol in relation to an increased demand during periods of severe stress, particularly prolonged critical illness such as multi-organ failure. This clinical entity, however, lacks clear-cut diagnostic criteria. What are the appropriate cortisol concentrations in the critically ill? Should base-line and adrenocorticotropic hormone-stimulated cortisol concentrations be assessed? The classical adrenocorticotropic hormone stimulation test is often used, but there are problems with interpreting its results. Other diagnostic tools, such as the low-dose adrenocorticotropic hormone test and relative eosinophilia, are promising but also lack proper criteria. A prompt response to hydrocortisone treatment is a major clue to the diagnosis. Recent studies with stress doses of hydrocortisone in sepsis and septic shock have shown a marked haemodynamic improvement, but whether patients with relative adrenal dysfunction benefit most from this treatment and whether there is definitely an effect on outcome is still undecided.

Adrenal Cortex↗

Macrophage migration inhibitory factor and hypothalamo-pituitary-adrenal function during critical illness.

In patients with septic shock (n = 32), multitrauma (n = 8), and hospitalized matched controls (n = 41), we serially measured serum macrophage inhibitory factor (MIF), cortisol, plasma ACTH, tumor necrosis factor-alpha, and interleukin-6 (IL-6) immunoreactivity during 14 days or until discharge/death. MIF levels were significantly elevated on day 1 in septic shock (14.3 +/- 4.5 microg/L), as opposed to trauma (3.1 +/- 1.7 microg/L) and control patients (2.5 +/- 2.1 microg/L). The time course of MIF, parallel to cortisol, but in contrast to ACTH, showed persistently elevated levels in septic patients. On admission, nonsurvivors of septic shock (n = 11) showed significantly higher MIF levels than survivors (18.4 +/- 4.8 and 10.2 +/- 4.2 microg/L, respectively). Patients with septic adult respiratory distress syndrome (ARDS; n = 8) showed higher MIF levels than those who did not develop ARDS (19.4 +/- 4.7 vs. 9.2 +/- 4.3 microg/L, respectively). Multiple logistic regression analysis demonstrated that both MIF and ARDS were independent predictors of adverse outcome. On admission, tumor necrosis factor-alpha, IL-6, procalcitonin, and lipopolysaccharide-binding protein levels were higher in patients with septic shock than in patients with multitrauma. In septic patients, regression analysis showed significant correlations between MIF and cortisol as well as between MIF and IL-6 levels and disease severity scores. No relation was found between MIF and markers of the acute phase response (procalcitonin, C- reactive protein, and lipopolysaccharide-binding protein). In multitrauma patients, MIF levels were not elevated at any time point and were not related to other variables. Our data suggest that during immune-mediated inflammation (such as septic shock) MIF is an important neuroendocrine mediator: a contraregulator of the immunosuppressive effects of glucocorticoids.

Aged↗

The low dose (1 microg) ACTH stimulation test for assessment of the hypothalamo-pituitary-adrenal axis.

Traditional testing of the hypothalamo-pituitary-adrenal axis function has relied essentially upon the insulin tolerance test or the metyrapone challenge: both tests are not only uncomfortable, but carry also real dangers. The standard ACTH stimulation test uses an extremely hyperphysiological amount (250 microg) of ACTH to evaluate a physiologic response, which may result in false normal responses. The proposed low dose (1 microg) ACTH test is more physiological and more sensitive, especially in cases of mild adrenal insufficiency and allows also to assess pituitary-adrenal suppression after long-term treatment with glucocorticoids. According to the rules of evidence-based medicine, the low dose ACTH test should replace the conventional 250 microg test when evaluating for central adrenal insufficiency.

Adrenal Insufficiency↗

Cross-lineage T cell receptor gene rearrangements occur in more than ninety percent of childhood precursor-B acute lymphoblastic leukemias: alternative PCR targets for detection of minimal residual disease.

A large series of 202 childhood precursor-B cell acute lymphoblastic leukemia (ALL) patients was analyzed by Southern blotting (SB) for cross-lineage rearrangements and/or deletions in the T cell receptor TCRB, TCRG and TCRD loci. In 93% (187/201) of the precursor-B-ALL patients one or more genes were rearranged and/or deleted. TCRB gene rearrangements were found in 35% (69/196), TCRG gene rearrangements in 59% (113/192), TCRD gene rearrangements in 55% (112/202), and isolated monoallelic or biallelic deletions of TCRD loci in 34% (68/202) of the cases. TCRB gene rearrangements involved exclusively the Jbeta2 locus with complete V(D)Jbeta2 joinings in 53% of gene rearrangements and incomplete Dbeta-Jbeta2 gene rearrangements in 33%. TCRG gene rearrangements frequently occurred on both alleles (65% of cases) and in approximately 70% concerned rearrangements to Jgamma1 gene segments. Most rearranged TCRD alleles (80%) represented incomplete Vdelta2-Ddelta3 or Ddelta2-Ddelta3 gene rearrangements, while the remaining TCRD gene rearrangements remained unidentified. Subsequently, we evaluated, whether heteroduplex PCR analysis of rearranged TCRG and TCRD genes can be used for reliable identification of PCR targets for detection of minimal residual disease (MRD). The concordance between SB and heteroduplex PCR analysis for detection of the various types of clonal TCRG and TCRD gene rearrangements ranged between 78% and 87%. The discrepancies could be assigned to the presence of 'atypical' TCRD gene rearrangements or translocations only detectable by SB, but also to efficient PCR-based detection of rearrangements derived from small subclones, which are difficult to detect with SB. Indications for oligoclonality were observed in 38% and 30% of patients with TCRG and TCRD gene rearrangements, respectively, which is comparable to the frequency of oligoclonality in IGH locus. Based on the combined data it was possible to reduce the broad panel of six TCRD and 12 TCRG primer combinations for MRD studies to two TCRD combinations (Vdelta2-Ddelta3 and Ddelta2-Ddelta3) and six TCRG combinations (VgammaI, VgammaII, VgammaIV family-specific primers with Jgamma1.1/2.1 and Jgamma1.3/2.3 primers) resulting in the detection of 80% and 97% of all TCRD and TCRG gene rearrangements, respectively. Finally, the heteroduplex PCR data indicate that MRD monitoring with TCRG and/or TCRD targets is possible in approximately 80% of childhood precursor-B-ALL patients; approximately 55% of patients even have two TCRG and/or TCRD targets.

Adolescent↗

Heterogeneity in junctional regions of immunoglobulin kappa deleting element rearrangements in B cell leukemias: a new molecular target for detection of minimal residual disease.

Virtually all immunoglobulin kappa (IGK) gene deletions are mediated via rearrangements of the so-called kappa deleting element (Kde). Kde rearrangements occur either to Vkappa gene segments (Vkappa-Kde rearrangements) or to the heptamer recombination signal sequence in the Jkappa-Ckappa intron. Kde rearrangements were analyzed by the polymerase chain reaction (PCR) and heteroduplex analysis in 130 B-lineage leukemias: 63 precursor-B-acute lymphoblastic leukemias (ALL) and 67 chronic B cell leukemias. To obtain detailed information about Kde rearrangements, we sequenced 109 of the 189 detected junctional regions. Vkappa gene family usage in the Vkappa-Kde rearrangements in our series of B-lineage leukemias was comparable to Vkappa gene family usage in functional Vkappa-Jkappa rearrangements in normal and malignant mature B cells, except for a higher frequency of VkappaII family usage in precursor-B-ALL. Junctional region sequencing of the Kde rearrangements in precursor-B-ALL revealed a mean insertion of 4.7 nucleotides and a mean deletion of 9.5 nucleotides, resulting in an extensive junctional diversity, whereas in chronic B cell leukemias the insertion (1.9) and deletion (6.0) were significantly lower. The relatively extensive junctional diversity of the Kde rearrangements in precursor-B-ALL allowed us to design leukemia/patient-specific oligonucleotide probes, which were proven to be useful for detection of minimal residual disease (MRD) with sensitivities of 10(-4) to 10(-5). Kde rearrangements occur in approximately 50% of precursor-B-ALL cases and are likely to remain stable during the disease course, because Kde rearrangements are assumed to be 'end-stage' rearrangements, which cannot easily be replaced by continuing rearrangement processes. These findings indicate that junctional regions of Kde rearrangements in precursor-B-ALL represent new valuable patient-specific PCR targets for detection of MRD.

Gene Deletion↗

Identification of immunoglobulin lambda isotype gene rearrangements by Southern blot analysis.

The human immunoglobulin lambda (Ig(lambda)) gene locus contains seven homologous C(lambda) exons which are organized in a tandem array, each of which is preceded by a single J(lambda) gene segment. The J-C(lambda)1, J-C(lambda)2, J-C(lambda)3, and J-C(lambda)7 are functional gene regions and encode for the four Ig(lambda) isotypes, whereas J-C(lambda)4, J-C(lambda)5, and J-C(lambda)6 are non-functional (pseudo) Ig(lambda) gene regions. Recently, we demonstrated that Southern blot analysis with the IGLC3 probe in combined EcoRI/HindIII digests allows detection of approximately 95% of all clonal Ig(lambda) gene rearrangements in B cell malignancies. Although this single probe/enzyme combination is quite effective in detecting Ig(lambda) gene rearrangements, it should be noted that it results in a complex pattern of multiple germline bands of different density, which needs experience for correct interpretation. To improve further the reliable detection and identification of clonal Ig(lambda) gene rearrangements, we developed a new set of seven 'isotype-specific' DNA probes: the IGLC1D probe for the J-C(lambda)1 gene region, the IGLC2D probe for the J-C(lambda)2 gene region, the IGLJ2 probe for the highly homologous J-C(lambda)2 and J-C(lambda)3 gene regions, and the IGLC4D, IGLJ5, IGLJ6, and IGLJ7 probes for the last four J-C(lambda) gene regions, respectively. In combination with optimally chosen digests (ie HindIII, BglII, BamHI, and/or EcoRI) the seven probes indeed allow easy detection and identification of all rearrangements in the seven J-C(lambda) gene regions. The applicability of the probe/enzyme combinations was confirmed upon analysis of clonal 'Ig(lambda)-isotype' gene rearrangements in 40 B lineage malignancies.

Blotting, Southern↗

Immunologic effects of background prenatal and postnatal exposure to dioxins and polychlorinated biphenyls in Dutch infants.

Immunologic effects of pre- and postnatal polychlorinated biphenyl (PCB)/dioxin exposure in Dutch infants from birth to 18 mo of age are explored. The total study group consisted of 207 healthy mother-infant pairs, of which 105 infants were breast-fed and 102 children were bottle-fed. Prenatal PCB exposure was estimated by the PCB sum (PCB congeners 118, 138, 153, and 180) in maternal blood and the total toxic equivalent (TEQ) level in human milk (17 dioxin and 8 dioxin-like PCB congeners). Postnatal PCB/dioxin exposure was calculated as a product of the total TEQ level in human milk multiplied by the weeks of breast-feeding. The number of periods with rhinitis, bronchitis, tonsillitis, and otitis during the first 18 mo of life was used as an estimate of the health status of the infants. Humoral immunity was measured at 18 mo of age by detecting antibody levels to mumps, measles, and rubella. White blood cell counts (monocytes, granulocytes, and lymphocytes) and immunologic marker analyses CD4+ T-lymphocytes, CD8+ T-lymphocytes, activated T-lymphocytes (HLA-DR+CD3+), as well as T cell receptor (TcR) alpha beta+, TcR gamma delta+, CD4+CD45RA+ and CD4+CD45RO+ T-lymphocytes, B-lymphocytes (CD19+ and/or CD20+) and NK cells (CD16+ and/or CD56+/CD3-) in cord blood and venous blood at 3 and 18 mo of age were assessed in a subgroup of 55 infants. There was no relationship between pre- and postnatal PCB/dioxin exposure and upper or lower respiratory tract symptoms or humoral antibody production.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Dissociation of plasma adrenocorticotropin and cortisol levels in critically ill patients: possible role of endothelin and atrial natriuretic hormone.

The regulatory mechanisms of the hypothalamo-pituitary-adrenal system were studied in critically ill, intensive care unit patients. Serial measurements of immunoreactive ACTH-(1-39) (ACTHi), cortisol, endothelin-1 (ETi), and atrial natriuretic hormone (ANHi) were performed in blood samples of 18 patients with clinically defined sepsis, 12 critically ill patients after multiple trauma, and 15 hospitalized matched control subjects without acute illness for 8 consecutive days after admission. On admission, plasma levels of cortisol and ACTHi were significantly elevated in patients with sepsis (1.32 +/- 0.21 mumol/L and 130.0 +/- 38.2 pmol/L, mean +/- SD) and with multiple trauma (1.23 +/- 0.28 mumol/L and 123.7 +/- 41.3 pmol/L) compared to those in the control subjects (0.37 +/- 0.08 mumol/L and 15.6 +/- 5.8 pmol/L, respectively). The plasma cortisol levels of critically ill patients remained high (> 0.8 mumol/L) during the whole observation period. In contrast, plasma ACTHi levels decreased between days 3-5, reaching significantly lower levels on day 5 compared to those in the control group and remained below 5.0 pmol/L during the rest of the observation period. Plasma levels of ETi and ANHi were significantly elevated during the whole period in both patient groups (ETi, > 10 ng/L; ANHi, > 250 ng/L) compared to those in control subjects (< 5 and < 50 ng/L, respectively). The high plasma concentration of ETi observed in our patients may stimulate the steroid secretion of the adrenal cortex directly or potentiate the adrenal effect of ACTH. On the other hand, the increased concentration of ANHi found in critically ill patients together with the increased plasma cortisol level may explain the inhibition of ACTH secretion. Accordingly, we speculate that the high ET level exerts a positive drive on the adrenocortical level, that the high ANH level has an inhibitory effect on the hypothalamo-pituitary level, and that both mechanisms play a role in regulation of the hypothalamo-pituitary-adrenal axis during critical illness.

Adrenocorticotropic Hormone↗

Heterogeneity of proliferative responses of human B cell precursor acute lymphoblastic leukemia (BCP-ALL) cells to interleukin 7 (IL-7): no correlation with immunoglobulin gene status and expression of IL-7 receptor or IL-2/IL-4/IL-7 receptor common gamma chain genes.

Interleukin 7 (IL-7) stimulates proliferation of normal human and murine B cell precursor (BCP) cells in a distinct fashion, depending on the stage of maturation of the cells. For instance, the productive rearrangement of the immunoglobulin heavy chain gene has been demonstrated to be essential for the response of BCP cells to IL-7 as the single proliferation stimulus. IL-7 activates a receptor that consists of the IL-7R protein and the common gamma chain (gamma c). BCP acute lymphoblastic leukemia (BCP-ALL) cells variably respond to IL-7. Among 72 cases of BCP-ALL IL-7 activated DNA synthesis in 34. In four cases inhibition of DNA synthesis was seen. In the remaining 38 cases IL-7 exerted no effects. We determined whether this heterogeneity in IL-7 response could be correlated with parameters that could influence the IL-7 response. Firstly we show that, in contrast to the murine BCP cells, the IL-7 response of human BCP-ALL cells did not correlate with the status of IgH chain gene rearrangement and expression, nor with the rearrangement of IgL chain genes. Subsequently, it is demonstrated that IL-7R protein and transcripts as well as gamma c transcripts are equally present in the IL-7 responsive and nonresponsive BCP-ALL samples, indicating that the defective expression of these chains could not be held responsible for IL-7 response failures. Finally, we observed that kit ligand (KL), known to synergize with IL-7 in the most primitive stages of normal B cell development, did not enhance the IL-7 responses of BCP-ALL cells.

Animals↗