Medication Outcome in ECT-Resistant Depression

The outcome of antidepressant treatment in 12 cases of electroconvulsive therapy (ECT)-resistant depression is presented. Eight patients had been refractory to a clinically adequate course of ECT (Hamilton Depression Scale improvement <20%) and four were partial responders (improvement 20-49%). All remitted completely on antidepressant medication within 2.2 +/- 1.1 (mean +/- SD) months of the ECT course. Remission was associated with clomipramine treatment (139 +/- 49.7 mg/day) in seven cases and maprotiline (125 mg/day) in one case. Four patients who did not respond to a tricyclic antidepressant alone remitted following supplementation (of clomipramine in 2 cases, clomipramine + haloperidol in 1 case, and imipramine in 1 case) with lithium carbonate. Although a delayed therapeutic response to ECT cannot be excluded, the results suggest that ECT may alter the sensitivity of refractory patients to antidepressant medication.     

Monoclonal anti-(T,G)-A—L antibodies: Characterization of fine specificity and idiotype expression

The technique of polyethylene glycol mediated cell fusion was used to establish 22 monoclonal cell lines secreting anti-(T,G)-A—L antibody. Cell lines were derived from C3H.SW and B10 mice and produced antibody with light chains and predominantly γ₁, heavy chains. Fine-specificity analysis demonstrated that 15 cell lines made antibodies that also recognize a determinant present on GAT, GT (9:1) and GT (1:1), whereas little, if any, serum antibody demonstrates this cross-reaction. Fourteen antibodies, derived from both B10 and C3H.SW mice, bear idiotypic determinants defined by Lewis anti-[B10 anti-(T,G)-A—L], but only two, both from C3H.SW mice, react with Lewis anti-[C3H.SW anti-(T,G)-A—L]. Adsorption studies indicate that no hybridoma tested bore the complete set of idiotypic determinants defined by either serum.     

Raised carcinoembryonic antigen level as an indicator of recurrent disease in follow up of patients with colorectal cancer.

BACKGROUND. Serum carcinoembryonic antigen level is raised in 80% of patients undergoing colonic resection for cancer. Subsequent elevation in the follow-up period may precede signs and symptoms as an indicator of recurrent disease. there is little evidence that "classical" follow up of patients in the general surgical outpatient clinic improves either survival or quality of life. Regular carcinoembryonic antigen level estimation requested by the general practitioner, allied to day-case colonoscopic surveillance may be a more rational approach. AIM. A study was undertaken to investigate the relationship between raised carcinoembryonic antigen level and the recurrence of colorectal cancer in patients following a curative primary resection. METHOD. Retrospective analysis was carried out on the notes of 125 patients who had attended a dedicated hospital colorectal follow-up clinic between 1988 and 1992. Carcinoembryonic antigen level data were obtained by subsequent examination of the University of Edinburgh Department of Clinical Chemistry (immunoassay section) carcinoembryonic antigen database. RESULTS. A single carcinoembryonic level result of more than 100 ul-1 (normal range less than 60 ul-1) was found to be a highly sensitive (87%), specific (89%), and accurate (88%) indicator of recurrent disease. Raised carcinoembryonic antigen level preceded symptoms in 72% of patients with recurrence of colorectal cancer. CONCLUSION. Sequential laboratory estimation of carcinoembryonic antigen level organized by the general practitioner may represent an accurate method of detecting recurrent colorectal disease. Hospital review could be limited to colonoscopic surveillance and restaging of patients referred with evidence of recurrent disease.     

Inhibition of platelet adherence to brain microvasculature protects against severe Plasmodium berghei malaria

Some patients with Plasmodium falciparum infections develop cerebral malaria, acute respiratory distress, and shock and ultimately die even though drug therapy has eliminated the parasite from the blood, suggesting that a systemic inflammatory response contributes to malarial pathogenesis. Plasmodium berghei-infected mice are a well-recognized model of severe malaria (experimental severe malaria [ESM]), and infected mice exhibit a systemic inflammatory response. Because platelets are proposed to contribute to ESM and other systemic inflammatory responses, we determined whether platelet adherence contributes to experimental malarial pathogenesis. Indeed, a significant (P < 0.005) increase in the number of rolling and adherent platelets was observed by intravital microscopy in brain venules of P. berghei-infected mice compared with the number in uninfected controls. P-selectin- or ICAM-1-deficient mice exhibit increased survival after P. berghei infection. We observed a significant (P < 0.0001) reduction in the morbidity of mice injected with anti-CD41 (alpha(IIb) or gpIIb) monoclonal antibody on day 1 of P. berghei infection compared with the morbidity of infected controls injected with rat immunoglobulin G. Additionally, platelet rolling and adhesion in brain venules were reduced in P. berghei mice lacking either P-selectin or ICAM-1 or when the platelets were coated with anti-CD41 monoclonal antibody. Unlike other inflammatory conditions, we did not detect platelet-leukocyte interactions during P. berghei malaria. Because (i). leukocyte adhesion is not markedly altered in the absence of P-selectin or ICAM-1 and (ii). CD41 is not an adhesion molecule for parasitized erythrocytes, these findings support the hypothesis that inhibition of platelet adhesion to the brain microvasculature protects against development of malarial pathogenesis.     

Mutations of OCTN2, an organic cation/carnitine transporter, lead to deficient cellular carnitine uptake in primary carnitine deficiency

Systemic primary carnitine deficiency (CDSP, OMIM 212140) is an autosomal recessive disease characterized by low serum and intracellular concentrations of carnitine. CDSP may present with acute metabolic derangement simulating Reye's syndrome within the first 2 years of life. After 3 years of age, patients with CDSP may present with cardiomyopathy and muscle weakness. A linkage with D5S436 in 5q was reported in a family. A recently cloned homologue of the organic cation transporter, OCTN2, which has sodium-dependent carnitine uptake properties, was also mapped to the same locus. We screened for mutation in OCTN2 in a confirmed CDSP family. One truncating mutation (Trp132Stop) and one missense mutation (Pro478Leu) of OCTN2 were identified together with two silent polymorphisms. Expression of the mutant cDNAs revealed virtually no uptake activity for both mutations. Our data indicate that mutations in OCTN2 are responsible for CDSP. Identification of the underlying gene in this disease will allow rapid detection of carriers and postnatal diagnosis of affected patients.     

Intestinal antilectin immunoglobulin A antibody response and immunity to Entamoeba dispar infection following cure of amebic liver abscess

We followed 93 subjects with amebic liver abscess (ALA) and 963 close associate controls at 3-month intervals for 36 months to characterize intestinal and humoral antibody responses to the amebic galactose-inhibitable lectin and to determine whether immunity developed to Entamoeba histolytica or Entamoeba dispar infection following cure of ALA. We found that ALA subjects had a higher prevalence and level of intestinal antilectin immunoglobulin A (IgA) and serum anti-LC3 (cysteine-rich recombinant lectin protein) IgA and IgG antibodies, P < 0.01 and P < 0.05, respectively, compared to controls. The intestinal antilectin IgA antibody response was sustained over a longer time period in ALA subjects (71.8% remained positive at 18 months and 52.6% at 36 months, P < 0.001 compared to 17.6% and 10.3% of controls, respectively). ALA subjects were highly immune to E. dispar infection throughout the study (0% infected at 6 and 36 months, compared to 6.5% and 4.9% of control subjects, respectively, P < 0.05). Upon entry into the study, 6.3% of ALA subjects were infected with E. histolytica; the incidence of new E. histolytica infections in controls (as determined by culture) was too low (1.4%) to determine whether ALA subjects exhibited immunity to new infections. We found that stool cultures every 3 months markedly underestimated the occurrence of new E. histolytica infections, as 15.3% of controls seroconverted after 12 months of follow-up. Unfortunately, under the field conditions present in Durban, South Africa, enzyme-linked immunosorbent assay for detection of lectin antigen in stool yielded unreliable results. In summary, subjects cured of ALA exhibited sustained mucosal IgA antibody responses to the amebic galactose-inhibitable lectin and a high level of immunity to E. dispar infection. Determination of immunity to E. histolytica following cure of ALA will require the use of more sensitive and reliable diagnostic methods.     

Evaluation of a dipstick ELISA and a rapid immunochromatographic test for diagnosis of Dengue virus infection

Here we report standardization of a dipstick enzyme-linked immunosorbent assay (ELISA, Dipstick ELISA) and its comparative evaluation with a commercial Rapid PanBio Immunochromatographic test (IC test) for detection of Dengue (DEN) virus-specific IgM and IgG antibodies in patient sera. Among crude and purified viral antigens prepared from mouse brains or cell cultures, a DEN virus type 2 antigen purified from cell cultures by sucrose density gradient centrifugation was found superior in terms of the signal/ noise (S/N) ratio in the assay system. The sensitivity of detection of the virus by specific IgM antibody was improved by removal of IgG from patient sera prior to testing. The evaluation of the Dipstick ELISA by use of 156 serum samples revealed an overall accordance of 96% and 93% with the IC test in detection of IgM antibodies to DEN viruses (IgM antibodies) and IgG antibodies to DEN viruses (IgG antibodies), respectively. The sensitivity of the Dipstick ELISA and the IC test with reference to the mu-capture ELISA was 83% and 87%, respectively, with a specificity of 98% in both cases. The sensitivity of the Dipstick ELISA with reference to the IC test in detecting IgM and IgG antibodies was 84% and 94%, respectively, and the specificity of the Dipstick ELISA was 98% and 92%, respectively.     

Cholinergic and serotonergic alterations in the rat hippocampus following trimethyltin exposure and fetal neural transplantation

The M2 receptor (M2-mAChR) is quantitatively the dominant muscarinic subtype in animal bladders. The alterations in its protein quantity and biosynthesis during diabetic cystopathy were investigated. Three-month-old male Wistar rats were divided into two groups: (1) 2-week-old diabetics; and (2) normoglycemic control rats. Diabetes was induced by single intravenous injection of 60 mg/kg streptozotocin. The amount of M2 receptor protein in the rat bladder body tissue was measured by Western immunoblotting using monoclonal antibodies. For determination of M2 muscarinic receptor mRNA in the bladder tissue, the method of Northern blotting was employed. The results of the Western immunoblotting showed that the amount of M2-mAChR protein in the diabetic bladder was significantly increased by 40.0 +/- 6.2% when compared with the control bladder (P < 0.05, n = 8). The Northern blotting demonstrated a 69.3 +/- 8.5% increase of the M2-mAChR mRNA in the diabetic bladder (P < 0.05, n = 8). The findings of the present study demonstrated an up-regulation of M2-mAChR biosynthesis in the diabetic urinary bladder. This phenomenon could lead to increased reactivity to acetylcholine and thus results in detrusor instability.     

Secretagogue effects on intracellular calcium in pancreatic duct cells

Regulation of intracellular free calcium ([Ca²⁺]_i) in single epithelial duct cells of isolated rat and guinea pig pancreatic interlobular ducts by secretin, carbachol and cholecystokinin was studied by microspectrofluorometry using the Ca²⁺-sensitive, fluorescent probe Fura-2. Rat and guinea pig duct cells exhibited mean resting [Ca²⁺]_i of 84 nM and 61 nM, respectively, which increased by 50%–100% in response to carbachol stimulation, thus demonstrating the presence of physiologically responsive cholinergic receptors in pancreatic ducts of both species. The carbachol-induced increase in [Ca²⁺]_i involved both mobilization of Ca²⁺ from intracellular stores and stimulation of influx of extracellular Ca²⁺. In contrast, neither cholecystokinin nor secretin showed reproducible or sizeable increses in [Ca²⁺]_i. Both rat and guinea pig duct cells showed considerable resting Ca²⁺ permeability. Lowering or raising the extracellular [Ca²⁺]_i led, respectively, to a decrease or increase in the resting [Ca²⁺]_i. Application of Mn²⁺ resulted in a quenching of the fluorescence signal indicating its entry into the cell. The resting Ca²⁺ and Mn²⁺ permeability could be blocked by La³⁺ suggesting that it is mediated by a Ca²⁺ channel.     

Macrophages but not B cells from aged mice are defective in stimulating autoreactive T cells in vitro

In the present study the effect of aging on the capacity of Ia+ cells to stimulate autoreactive T cells in the syngeneic mixed lymphocyte reaction (SMLR) was investigated. Using young CD4+ T cells as responders, it was observed that unseparated whole spleen cells from aged mice had normal stimulatory activity comparable to that of young spleen cells. Interestingly, however, when purified splenic adherent cells (SAC) enriched for macrophages or splenic B cells were used as stimulators, aged SAC but not aged B cells were found to be defective in stimulating autoreactive T cells. This defect in aged SAC was not due to decreased expression of Ia antigens since the percentage of Ia+ SAC and density of Ia antigen expression was similar in both young and old mice. Also, the B cells from aged mice expressed normal levels of Ia antigens. Aged SAC, when mixed with young SAC could also actively suppress the normal SMLR. However, this suppression was not due to increased prostaglandin production but was found to be associated with interleukin-1 (IL-1) regulation, inasmuch as addition of exogenous IL-1 could completely reconstitute the defective stimulatory activity of aged SAC and also abolished the suppressor activity of the SAC. Aged mice also demonstrated an intrinsic defect in the CD4+ T cells responding in the SMLR. Together, our studies on the SMLR demonstrate an age-related defect in responder autoreactive T cells and in stimulator splenic macrophages but not in the stimulatory activity of B cells.