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Biomedical subjects

D C Henderson

Publications and source records attributed to D C Henderson.

At least 19 recordsLinked to original sources
PubMed1999

A placebo-controlled crossover trial of D-cycloserine added to clozapine in patients with schizophrenia.

BACKGROUND: D-Cycloserine, a partial agonist at the glycine recognition site of the NMDA receptor, has previously been shown to improve negative symptoms when added to conventional antipsychotics and, in one preliminary dose-finding study, worsened negative symptoms when added to clozapine. METHODS: Seventeen schizophrenia outpatients treated with clozapine were assigned in random order to 6-week trials of D-cycloserine 50 mg/day and placebo in a crossover design separated by a 1 week placebo washout. RESULTS: Eleven patients competed the 13-week study. D-Cycloserine significantly worsened ratings of negative symptoms compared to placebo but did not significantly affect ratings of psychotic symptoms. CONCLUSIONS: The differing effects of D-cycloserine on negative symptoms when added to clozapine compared to conventional antipsychotics suggests that activation of the glycine recognition site may play a role in clozapine's efficacy for negative symptoms.

Adult↗
PubMed1998

Relation between depression and circulating immune products in patients with advanced colorectal cancer.

We have previously suggested that colorectal liver metastases might produce 'toxins' that reduce both quality of life (QoL) and survival. In this study we assessed whether QoL in patients with such metastases was related to immune activation, as determined by increased serum levels of interleukin 6 (IL6), soluble tumour necrosis factor receptor 1 (sTNFr1), soluble interleukin 2 receptor alpha (sIL2r alpha) or the interferon-gamma marker neopterin. Serum IL6, sTNFr1, sIL2r alpha, neopterin, alkaline phosphatase and carcinoembryonic antigen levels, liver metastasis volume, and QoL (Hospital Anxiety and Depression [HAD] scale, Rotterdam Symptom Checklist [RSC], and Sickness Impact Profile [SIP]) were measured in 43 patients. There were significant positive correlations between serum sIL2r alpha and HAD depression score (r = 0.66, P = 0.0001), RSC physical symptom score (r = 0.46, P < 0.01), and SIP score (r = 0.47, P = 0.009). Multiple regression analysis suggested that serum sIL2r alpha level was a significant independent predictor of HAD depression score. Although survival was shorter (logrank test P < 0.05) where sIL2r alpha, sTNFr1 and IL6 levels were higher, the ability of sIL2r alpha to predict HAD depression score was independent of survival.

Aged↗
PubMed1998

Switching from clozapine to olanzapine in treatment-refractory schizophrenia: safety, clinical efficacy, and predictors of response.

BACKGROUND: In our experience, many of our schizophrenic patients treated with clozapine request the newer atypical antipsychotic agents in order to eliminate the weekly blood monitoring. However, there are few guidelines available to clinicians interested in switching patients successfully treated with clozapine to olanzapine. METHOD: The goal of this study was to collect preliminary data on the safety, clinical effectiveness, and predictors of response of switching clozapine patients to olanzapine. In an open trial, 19 patients receiving clozapine were switched to olanzapine. RESULTS: Eight (42%) of 19 patients were considered responders. Seven patients decompensated seriously enough to require hospitalization. All 7 of these patients were restabilized on clozapine treatment in the hospital, and olanzapine was discontinued. In an additional 4 patients, clinical status worsened, and clozapine doses were titrated upwards and olanzapine was slowly discontinued. Overall, mean total Brief Psychiatric Rating Scale (BPRS) scores increased significantly from baseline to final assessment (p = .02). Responders had been treated for a significantly shorter period of time with clozapine prior to the switch compared to nonresponders (p = .04) and were receiving a lower dose of clozapine (p = .05). The final olanzapine dose did not differ between responders and nonresponders. All responders have remained on olanzapine treatment and are stable. CONCLUSION: In this open trial, the crossover from clozapine to olanzapine was generally well tolerated and resulted in a successful transition for 8 of the 19 patients. However, mean scores on the total BPRS and negative symptom and depressive symptom subscales significantly increased. Caution must be taken in determining which patients may benefit from the switch to olanzapine because of the risk of decompensation and hospitalization. Because this was an open trial, these findings require replication in a controlled trial.

Adult↗
PubMed1997

A glycoprotein pneumococcal conjugate vaccine primes for antibody responses to a pneumococcal polysaccharide vaccine in Gambian children.

BACKGROUND: Streptococcus pneumoniae is a major cause of acute respiratory infections and acute bacterial meningitis in children. Pneumococcal polysaccharide vaccines are poorly immunogenic in this highly vulnerable group, but protein polysaccharide conjugate vaccines are likely to be more effective. OBJECTIVES: To determine whether immunization of infants with a pneumococcal conjugate vaccine induces immunologic memory. METHODS: Eighty-four Gambian children, who had been vaccinated previously with two or three doses of a pentavalent pneumococcal conjugate vaccine (CRM197) or with a Haemophilus influenzae type b (Hib) conjugate vaccine were immunized when approximately 2 years old with a 23-valent pneumococcal polysaccharide vaccine, and a blood sample was obtained 10 days later. Pneumococcal antibody titers in prevaccination and postvaccination sera were measured by enzyme-linked immunosorbent assay and by an opsonophagocytic assay. RESULTS: On revaccination with a pneumococcal polysaccharide vaccine, children who had previously received pneumococcal conjugate vaccine had higher antibody concentrations to each of the five polysaccharide components of the conjugate vaccine than did control children. For type 6B polysaccharide, which is poorly immunogenic in young children, postvaccination antibody concentrations were 0.37, 27.6 and 50.9 microg/ml in children who had received no previous pneumococcal immunization or two or three doses of conjugate vaccine, respectively. Type 14 antibodies produced after revaccination were of high avidity and had opsonic activity. CONCLUSION: Vaccination of young infants with two or three doses of a pneumococcal conjugate vaccine primes the immune system to respond strongly and rapidly on subsequent exposure to pneumococcal polysaccharide.

Antibodies, Bacterial↗
PubMed1997

Severe pneumococcal disease and temporary splenic dysfunction.

We report a patient presenting with pneumonia in whom temporary splenic dysfunction was diagnosed by counting pitted red blood cells. This under-recognised condition caused a transient immunosuppression which may have had serious implications for our patient's recovery.

Adult↗
PubMed1996

AIDS-associated vacuolar myelopathy and tumor necrosis factor-alpha (TNF alpha).

The spinal cords from 15 patients with AIDS-associated vacuolar myelopathy (VM), 4 AIDS patients without VM, and 5 HIV-seronegative controls, were studied with immunocytochemistry for TNF alpha. CSF and blood from HIV-seropositive patients with VM (n = 16), non-vacuolar myelopathies (n = 8), CNS infection but no clinical myelopathy (n = 31), no clinical or radiological evidence of CNS disease (n = 9), and from 7 HIV-seronegative controls with motor neurone disease were assayed for TNF alpha using an ELISA technique. TNF alpha was present on immunostaining in all the 15 cords with VM studied. The stained cells were macrophages, microglia and endothelial cells. The amount of immunostaining was higher in cords with VM compared with cords from HIV-seropositive patients without VM (p = 0.001). The distribution of staining corresponded to the areas of pathology but did not correlate with the severity of the VM. Immunostaining was also higher in the HIV-seropositive group compared to the HIV-seronegative controls (p = 0.001). There was no significant difference in the levels of TNF alpha in the CSF of patients with VM compared to any of the other groups studied. Blood levels of TNF alpha were lower in the HIV-seropositive controls without CNS disease and in the HIV-seronegative MND controls, than in patients with VM, non-vacuolar myelopathies, and CNS disease. CSF TNF alpha levels did not appear to be a reliable indicator of intramedullary levels. The findings support the hypothesis that TNF alpha may be relevant in the pathogenesis of vacuolar change in VM.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Defective antibody-mediated opsonisation of S. pneumoniae in high risk patients detected by flow cytometry.

Invasive pneumococcal infection continues to be a significant cause of morbidity and mortality especially in patients with antibody deficiencies and disorders affecting the reticulo-endothelial system. Current recommendations for prophylaxis in these patients include immunization with 23-valent pneumococcal polysaccharide capsular vaccines. Post-immunization responses are commonly assessed by measuring serum antibody levels. However, there is no defined protective antibody range and this approach fails to determine the functional capacity of the antibodies. A simple, reproducible flow cytometric method of assessing the antibody-mediated opsonic activity against S. pneumoniae is described. This assay detected defective opsonic function in post-immunized at-risk patients who developed invasive pneumococcal infection.

Adult↗
PubMed1996

Inflammatory and immunological markers in preterm infants: correlation with disease.

Newborn infants often suffer from bacterial and viral infections without presenting typical symptoms. Therefore, reliable methods for detecting and monitoring sepsis in the newborn would be beneficial. In older patients C-reactive protein (CRP) and neopterin have proved useful serum markers of infection and inflammation. Both of these markers are regulated by cytokines, and it has been proposed that cytokines themselves could be used to monitor immune activation and infection. This study has examined the levels of CRP, neopterin, soluble IL-2R, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in cord blood samples from both premature and term neonates. Having established reference ranges for these analytes, serial measurements were made in babies requiring intensive care support. The results suggest that in preterm infants the simultaneous measurement of CRP and neopterin, and possibly soluble IL-2R, may provide an accurate early diagnosis of sepsis and may be of use in differentiating between bacterial and viral etiologies. In addition, serial measurement of these markers may help in the early diagnosis of necrotizing enterocolitis (NEC).

Biomarkers↗
PubMed1996

Risperidone as an adjunct to clozapine therapy in chronic schizophrenics.

BACKGROUND: Some treatment-resistant schizophrenic patients improve enough to remain out of the hospital but continue to have significant positive or negative symptoms. METHOD: The goal of this study was to assess the safety and potential efficacy of risperidone as an adjunct for schizophrenic patients treated with clozapine. In an open 4-week trial involving 12 DSM-III-R-diagnosed patients, the addition of risperidone to clozapine was well tolerated and did not affect serum clozapine concentrations significantly. RESULTS: Total Brief Psychiatric Rating Scale (BPRS) scores and subscales measuring positive symptoms, negative symptoms, and depressive symptoms were significantly reduced from baseline. Ten of 12 participants had a 20% or greater reduction in the total BPRS score. CONCLUSION: In this open trial, the addition of risperidone to clozapine was well tolerated and produced significant reduction of symptoms, suggesting that this may be a useful clinical approach. Because this was an open trial, the improvement we observed must be replicated in a controlled trial.

Adult↗
PubMed1995

Bone marrow transplantation in Batten disease (neuronal ceroid-lipofuscinosis). Will it work? Preliminary studies on coculture experiments and on bone marrow transplant in late infantile Batten disease.

Lymphocytes from a patient with preclinical late infantile Batten disease were cultured alone and with lymphocytes from donors, and the fate of the curvilinear inclusions characteristic of the disease was monitored by electron microscopy. There was no evidence of transfer of deficient enzyme or factor that might have caused removal of the stored material, and the curvilinear profiles remained in the cultured cells without signs of degradation. Cells stimulated to divide with phytohaemaglutinin did not exhibit storage in culture suggesting that storage is a function of the age of the cell. The patient received a bone marrow transplant at 2 7/12 years while still clinically unaffected, and the effect on lymphocytes and cells in skin and rectal biopsies was monitored by electron microscopy over a period of 9 months until the donor marrow became displaced by the host cells. He has had one seizure and now has neurophysiological evidence of late infantile Batten's disease. Bone marrow transplant may have no effect on material already stored but might prevent further build-up and halt the onset of the clinical symptoms although very recent studies on early (fetal) transplants in sheep with a form of Batten disease have shown no benefit.

Bone Marrow Transplantation↗
PubMed1995

Stimulus-dependent production of cytokines and pterins by peripheral blood mononuclear cells.

The cytokine profiles produced by peripheral blood mononuclear cell (PBMC) cultures were dependent upon the nature of the stimulus used. Powerful lymphocyte activators such as mitogens induced rapid cell proliferation together with the production of both inflammatory (IL-1 alpha, IL-1 beta, IL-6 and TNF alpha) and immune (IFN-gamma, TNF-alpha and TNF-beta) cytokines, and immune activation markers (soluble IL-2 receptor, neopterin and xanthopterin). Bacterial endotoxin failed to induce cell proliferation but resulted in the rapid production of inflammatory cytokines together with a short burst of IFN-gamma production, without the production of the other immune cytokines or activation markers. Alloantigen stimulation gave a typical immune cytokine and marker profile, with little or no production of inflammatory cytokines. Re-call antigens (candida and PPD) induced maximal cell proliferation at days 5 to 6, but induced little or no production of inflammatory cytokines. Markedly different immune cytokine profiles were obtained with these re-call antigens. Candida induced an early burst of IFN-gamma production on day 1 followed by later production of TNF-alpha. In cultures stimulated with PPD, both IFN-gamma and TNF-alpha were detected from day 2. With both re-call antigens, the levels of production of the activation markers were equivalent to the proliferative responses obtained.

Biopterins↗
PubMed1994

Immunological parameters in peripheral blood of patients with renal cell carcinoma before and after nephrectomy.

OBJECTIVE: To determine the effects of nephrectomy on the immune response of patients with renal cell carcinoma (RCC). PATIENTS AND METHODS: Five patients with RCC were monitored before and over a period of up to 3 months after nephrectomy. The aspects measured were the phenotypic expression of markers on circulating lymphocytes, circulating concentrations of cytokines, markers of inflammatory and immune responses, and natural killer (NK) cell and lymphokine-activated killer (LAK) cell activity in peripheral blood mononuclear cells (PBMC). The suppressive activity of patients' plasma on NK activity and ability to generate interleukin-2 (IL-2) induced LAK cells in PBMC of normal volunteers was also investigated. RESULTS: The results indicated that high CD4/8 ratios were present pre-nephrectomy with evidence of inflammatory responses and immune activation in some patients, particularly those with metastatic disease. CONCLUSION: The effect of nephrectomy was to decrease the inflammatory response and increase immune activation. Various defects in NK cell activity and LAK cell generation were demonstrated pre-surgery which slowly improved once the primary tumour had been removed and it is suggested that such defects could have contributed to tumour growth and development due to an ineffective immune response.

Adult↗
PubMed1993

Inter-relationships between pterins and cytokines produced during allogeneic immune reactions and possible use as early markers of immune activation.

The pterins neopterin and xanthopterin have been measured together with the cytokines IFN-gamma, TNF-alpha and TNF-beta in the supernatants of 20 allogeneic mixed lymphocyte reactions. We have calculated rank correlation coefficients between these analytes and the immune response. Our findings confirm that neopterin is a sensitive early marker of immune activation and show that another pterin, xanthopterin could be used likewise. Cytokine production was also proportional to immune activation but none could be used consistently as early markers of immune activation.

Biomarkers↗