RESUMO
The article reviews the changes in the structure of classification, diagnostic criteria for myeloid and histiocytic neoplasms in the 5th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (2022). Information is presented regarding new nosological forms, renaming and abolition of some previously existing ones. The importance of molecular genetic studies in the isolation of myeloid and histiocytic neoplasms and the need to apply these studies in clinical practice are emphasized. Myeloid and histiocytic precancerous and proliferative processes, genetic tumor syndromes, introduced into the classification for the first time, are considered.
Assuntos
Neoplasias Hematológicas , Neoplasias , Humanos , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/genética , Tecido Linfoide , Organização Mundial da SaúdeRESUMO
BACKGROUND: Metagenomic studies in recent years have demonstrated that all tissues of the human body studied by genomic and transcriptomic sequencing methods, both in pathological processes and in normality, contain fragments of DNA and RNA from a variety of microorganisms. The composition of tissue microbiota and its relationship with development of pathological changes are still poorly understood, despite increasing number of studies in this area every year. In this study, gene expression of the lymph node microbiome in reactive follicular hyperplasia and follicular lymphoma was investigated. OBJECTIVE: To study expression of lymph node microbiome genes in reactive follicular hyperplasia and follicular lymphoma. MATERIAL AND METHODS: The work included 38 biopsy samples of lymph nodes with follicular lymphoma of different cytological subtypes and 10 biopsy samples of lymph nodes with reactive follicular hyperplasia. Verification of diagnosis was carried out using standard histological, histochemical and immunohistochemical methods. Using sequencing method, the transcriptome was examined. Statistical analysis and data visualization were performed using the R programming language (version 4.2.1). RESULTS: Tumor lymph nodes are characterized by large Simpson and Shannon alpha diversity values (p-value = 0.026465 and p-value = 0.007122, respectively). Two clusters were discovered, characterized by different levels of relative abundance of microorganisms. CONCLUSION: It has been proven that diversity of microorganisms present in tumor tissue and their number are statistically significantly higher than corresponding indicators in the lymph nodes with follicular hyperplasia.
Assuntos
Linfoma Folicular , Microbiota , Humanos , Linfoma Folicular/diagnóstico , Linfoma Folicular/patologia , Hiperplasia/patologia , Linfonodos/patologia , Perfilação da Expressão Gênica , Microbiota/genéticaRESUMO
The paper discusses changes in the structure of the classification, criteria for the diagnosis of lymphoid neoplasms in the 5th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (2022). Changes are presented regarding new nosological units, renaming and abolition of some previously existing ones. The importance of molecular genetic studies in the isolation of many lymphomas and the need to apply these studies in everyday clinical practice are emphasized. Lymphoid precancerous processes and lymphoid proliferations introduced into the Classification for the first time are considered.
Assuntos
Linfoma , Neoplasias , Humanos , Organização Mundial da Saúde , Linfoma/diagnóstico , Linfoma/genética , Linfoma/patologia , Tecido Linfoide/patologiaRESUMO
Synaptotagmins (Syts) I and II are believed to act as Ca2+ sensors in the control of neurotransmission. Here we demonstrate that mast cells express Syt II in their lysosomal fraction. We further show that activation of mast cells by either aggregation of FcepsilonRI or by Ca2+ ionophores results in exocytosis of lysosomes, in addition to the well documented exocytosis of their secretory granules. Syt II directly regulates lysosomal exocytosis, whereby overexpression of Syt II inhibited Ca2+-triggered release of the lysosomal processed form of cathepsin D, whereas suppression of Syt II expression markedly potentiated this release. These findings provide evidence for a novel function of Syt II in negatively regulating Ca2+-triggered exocytosis of lysosomes, and suggest that Syt II-regulated secretion from lysosomes may play an important role in mast cell biology.
Assuntos
Cálcio/metabolismo , Lisossomos/metabolismo , Mastócitos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Calcimicina , Catepsina D/metabolismo , Grânulos Citoplasmáticos/imunologia , Exocitose/imunologia , Regulação da Expressão Gênica , Lisossomos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas do Tecido Nervoso/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores de IgE/metabolismo , Serotonina/metabolismo , Sinaptotagmina II , Acetato de Tetradecanoilforbol , Transfecção , beta-N-Acetil-Hexosaminidases/metabolismoRESUMO
Sirolimus (rapamycin, rapamune) is an effective immunosuppressant that has been widely used in solid organ transplantation. Recently, two disconcerting side effects, namely pulmonary toxicity, usually in the form of interstitial pneumonitis, and the onset of nephrotic range proteinuria, have been recognized. We report the case of a renal transplant recipient who had been on chronic anticoagulation therapy for a mechanical aortic valve, and who developed pulmonary distress necessitating emergent intubation 18 days after starting sirolimus therapy. Open lung biopsy showed diffuse alveolar hemorrhage with fibrin deposits in the alveolar spaces and small bronchi. Urine protein/creatinine ratio at that time was 16.7. Upon discontinuation of sirolimus, alveolar hemorrhage and nephrotic range proteinuria resolved. We suggest that extra vigilance be paid in individuals who are on chronic anticoagulation and who are started on sirolimus.
Assuntos
Anticoagulantes/efeitos adversos , Hemorragia/induzido quimicamente , Imunossupressores/efeitos adversos , Transplante de Rim , Pneumopatias/induzido quimicamente , Alvéolos Pulmonares , Sirolimo/efeitos adversos , Adulto , Anticoagulantes/uso terapêutico , Feminino , Próteses Valvulares Cardíacas , Hemorragia/diagnóstico , Humanos , Pneumopatias/diagnóstico , Alvéolos Pulmonares/patologiaRESUMO
The pentapeptide leucine enkephalin induced down-regulation of enkephalin receptors in neuroblastoma-glioma NG108-15 hybrid cells in a reversible fashion, whereas the stable enkephalin analogue D-Ala2-Met-enkephalinamide (AMEA), and the potent opiate alkaloid, etorphine, had a prolonged effect. The opiate alkaloid, morphine, which has low affinity to delta-type enkephalin receptors of these cells did not induce down-regulation, whereas AMEA decreased the binding of both opiate agonists and antagonists but had no effect on the binding of the alpha 2-adrenergic ligand, [3H]yohimbine. From several experiments that were designed to remove the tightly bound AMEA, and from experiments with solubilized receptor we ruled out the possibility that the decreased binding capacity of enkephalin-treated cells reflects only receptor masking. The study suggests that down-regulation of enkephalin receptors that may also occur in vivo can account for some of the abnormal physiological responses of subjects treated chromically with opiates. However, since opiates from the morphine type can induce opiate tolerance in vivo, but not down-regulation of enkephalin receptors in the cultured cells, we suggest that down-regulation of delta-type opiate receptors may not be prerequisite for the development of the physiological tolerance/dependence on these alkaloids.
Assuntos
Alcaloides/farmacologia , Encefalinas/farmacologia , Receptores Opioides/efeitos dos fármacos , Animais , Tolerância a Medicamentos , Encefalina Leucina/farmacologia , Encefalina Metionina/análogos & derivados , Encefalina Metionina/farmacologia , Etorfina/farmacologia , Glioma/metabolismo , Células Híbridas/metabolismo , Técnicas In Vitro , Morfina/farmacologia , Neuroblastoma/metabolismo , Ratos , SolubilidadeRESUMO
Mast cells, which are capable of releasing a multitude of preformed and newly generated biological mediators and cytokines, are involved in various inflammatory processes. We studied whether histamine, a mast cell degranulation product, influences the adhesive interactions of T cells with extracellular matrix (ECM) glycoproteins, an event that occurs at sites of inflammation and is mediated primarily by virtue of cell-surface receptors of the beta 1-integrin subfamily. A prerequisite of lymphocyte-ECM interactions is activation of the cells, which modulates the affinity of the otherwise inactive integrins. Isolated rat CD4+ T cells were preincubated with histamine and activated with phorbol myristate acetate (PMA), and their ability to adhere to immobilized ECM components (fibronectin and laminin) was determined. Preincubation with histamine resulted in a 40-50% decrease in the adhesion of the CD4+ cells to both fibronectin or laminin. The notion that inhibition of T cell adhesion to ECM proteins by histamine-induced increase of the cells' intracellular levels of cAMP, thus interfering with calcium influx-associated events that occur during T cell activation, is supported by the finding that T cell adhesion was also abrogated by pharmacological inducers of cAMP. When the T cells were preincubated with supernatants of immunologically activated mast cells and then activated with PMA, a 40-50% inhibition of their adhesion to fibronectin or laminin was also observed. The inhibitory moiety present in the mast cell degranulation supernatants was resistant to heat (80 degrees C). Histamine exerted its suppressive effect on adhesion of T cells via their H2 receptors, as pretreatment with H2 antagonists abrogated the inhibitory effect. Thus, both purified histamine and mast cell-secreted histamine appear to be capable of affecting T cell interactions with ECM.
Assuntos
Linfócitos T CD4-Positivos/citologia , Adesão Celular/efeitos dos fármacos , Histamina/farmacologia , Mastócitos/fisiologia , Animais , Bucladesina/farmacologia , Linfócitos T CD4-Positivos/metabolismo , Cálcio/metabolismo , Moléculas de Adesão Celular/metabolismo , Degranulação Celular , Colforsina/farmacologia , Regulação para Baixo , Proteínas da Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Humanos , Integrinas/metabolismo , Laminina/metabolismo , Ratos , Ratos Endogâmicos Lew , Receptores Histamínicos H2/fisiologia , Sistemas do Segundo MensageiroRESUMO
PIP: From June 1970 through January 1971, a psychological comparison between 99 single white pregnant women seeking abortion and a control group of 79 single nonpregnant women of similar background showed that, as a group, the women seeking abortion were no more neurotic than nonpregnant women of the same ages. Both groups (comprised mainly of college students) were equally informed about contraceptives. 77% of the abortion group used no contraceptives prior to the pregnancy. 82% of the sexually active members of the control group consistently used contraceptives. Conscious motivational factors, such as guilt over use of contraception, reactions to loss, or severe acting-out character disorders, may have influenced the occurrence of the pregnancy in 40% of the abortion group. Psychological testing showed that the pregnant group stated themselves as more impulsive and as tending to externalize aggression.^ieng
Assuntos
Aborto Terapêutico , Motivação , Adolescente , Ansiedade , Atitude , Anticoncepção , Depressão , Feminino , Humanos , Entrevista Psicológica , Menarca , Distúrbios Menstruais/epidemiologia , Transtornos Neuróticos , Personalidade , Inventário de Personalidade , Gravidez , Autoimagem , Educação Sexual , Comportamento Sexual , Pessoa Solteira , Estudantes , UniversidadesRESUMO
Free cytosolic calcium content [Ca2+]i was determined in peripheral blood mononuclear cells (PBMC) from healthy volunteers, Alzheimer's disease and multi-infarct dementia patients. Measurement of [Ca2+]i by the fluorescent dye quin-2, before and at several time intervals during incubation with phytohemagglutinin (PHA), showed a higher resting [Ca2+]i in PBMC of Alzheimer's disease patients as compared to controls and multi-infarct dementia patients. However, the addition of supra-optimal PHA doses (100 micrograms/ml) induced strikingly higher [Ca2+]i levels in Alzheimer's disease patients (1647 +/- 200 nM versus 398 +/- 27 nM in controls, and 346 +/- 40 nM in multi-infarct dementia patients). The increased [Ca2+]i concentration was also found after a specific stimulation with a monoclonal anti-CD3 antibody. The results may have important implications in understanding the pathophysiology of Alzheimer's disease and suggest that [Ca2+]i may prove diagnostically valuable.
Assuntos
Doença de Alzheimer/sangue , Cálcio/metabolismo , Citosol/metabolismo , Linfócitos/metabolismo , Idoso , Aminoquinolinas , Anticorpos Monoclonais/farmacologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Complexo CD3 , Demência por Múltiplos Infartos/sangue , Feminino , Corantes Fluorescentes , Humanos , Cinética , Linfócitos/ultraestrutura , Masculino , Fito-Hemaglutininas/farmacologia , Receptores de Antígenos de Linfócitos T/imunologiaRESUMO
Chronic graft versus host disease (cGVHD) across minor histocompatibility barriers is associated with the development of cutaneous fibrosis, disappearance of mast cells and immunosuppression. The idea, which has been the basis of our previous and present studies, is that fibroblasts are not only a target for modulation in cGVHD, but also have effector roles in this condition. In the present study we investigated the production of prostaglandin E2 (PGE2) and of collagen by cultured dermal fibroblasts obtained from cGVHD and control mice. Early in the development of the disease (Day 8) cGVHD fibroblasts generated constitutively more PGE2 (3-fold) than did control fibroblasts. Thereafter, PGE2 production declined to near normal levels by Day 20 post cGVHD induction. On the other hand, at this time point cGVHD fibroblasts displayed an enhanced synthesis of collagen as compared to the control fibroblasts and to earlier time points. Therefore, PGE2 synthesis appears to inversely correlate with collagen synthesis by cGVHD fibroblasts. We propose that fibroblasts may contribute to the development of immunosuppression, which characterizes the early phase of cGVHD.
Assuntos
Dinoprostona/biossíntese , Fibroblastos/metabolismo , Doença Enxerto-Hospedeiro/imunologia , Pele/imunologia , Animais , Células Cultivadas , Colágeno/biossíntese , Feminino , Fibroblastos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Pele/citologia , Fatores de TempoRESUMO
The mast cell lines rat basophilic leukemia (RBL) and mouse C57 cells respond to IgE/antigen complexes by degranulation. Treatment of these cells with 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), (10-100 nM) for 24-48 h enhanced IgE/antigen-induced exocytosis as monitored by release of hexosaminidase. A short term incubation with the hormone did not affect exocytosis, ruling out a rapid non genomic mechanism. The presence of vitamin D receptors, demonstrated by immunoblotting and the lack of effect of 24,25(OH)2D3 suggest a role for these receptors in the enhancing effect. 1,25(OH)2D3 also enhanced exocytosis induced by the calcium ionophore A23187 in the presence or absence of phorbol ester indicating modulation of events distal to signal transduction. 1,25(OH)2D3 enhanced exocytosis in the presence of cytochalasin D, indicating that the action of the hormone is not due to effects on microfilament structure. The results of this study suggest that 1,25(OH)2D3 may affect the allergic or pro-inflammatory potential of mast cells.
Assuntos
Calcitriol/farmacologia , Degranulação Celular/efeitos dos fármacos , Mastócitos/fisiologia , Animais , Antígenos/farmacologia , Calcimicina/farmacologia , Citocalasina D/farmacologia , Dinitrofenóis/imunologia , Exocitose/efeitos dos fármacos , Imunoglobulina E/imunologia , Imunoglobulina E/farmacologia , Leucemia Basofílica Aguda , Mastócitos/efeitos dos fármacos , Camundongos , Inibidores da Síntese de Ácido Nucleico/farmacologia , Ratos , Receptores de Calcitriol/análise , Receptores de Calcitriol/fisiologia , Células Tumorais Cultivadas , beta-N-Acetil-Hexosaminidases/metabolismoRESUMO
A preliminary trial of oral delta-9-tetrahydrocannabinol (THC) demonstrated an analgesic effect of the drug in patients experiencing cancer pain. Placebo and 5, 10, 15, and 20 mg THC were administered double blind to ten patients. Pain relief significantly superior to placebo was demonstrated at high dose levels (15 and 20 mg). At these levels, substantial sedation and mental clouding were reported.
Assuntos
Analgésicos/uso terapêutico , Cannabis/uso terapêutico , Dronabinol/uso terapêutico , Fitoterapia , Administração Oral , Pressão Sanguínea/efeitos dos fármacos , Ensaios Clínicos como Assunto , Relação Dose-Resposta a Droga , Dronabinol/administração & dosagem , Dronabinol/efeitos adversos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Neoplasias/complicações , Dor/tratamento farmacológico , Dor/etiologia , Placebos , Fatores de TempoRESUMO
OBJECTIVE: To report an unusual presentation of a patient with unicornuate uterus and a noncommunicating functional rudimentary horn and discuss related patient management issues. SETTING: University hospital. PATIENT: A 27-year-old woman who presented with cyclic abdominal pain after a postpartum tubal ligation. INTERVENTION: Diagnostic studies followed by a laparotomy and resection of the rudimentary horn. RESULTS: Resolution of patient's symptoms. CONCLUSIONS: Patients with a unicornuate uterus and a rudimentary horn recognized for the first time during a tubal ligation require individualized management depending in part on the precise nature of the horn.
Assuntos
Ductos Paramesonéfricos/anormalidades , Útero/anormalidades , Adulto , Feminino , Humanos , Dor/etiologia , Esterilização Tubária/efeitos adversosRESUMO
Chronic Graft-versus-Host disease (GVHD) is characterized by overt immunosuppression. In addition, the skin is a major anatomical site affected in chronic GVHD for reasons not yet known. Increased collagen deposition, a mononuclear cell infiltrate in the dermis as well as loss of fat and appendages, are observed in the skin. The inflammatory cytokine IL-1 was shown to affect fibroblast proliferation and secretory activities. In the present study, IL-1 generation by dermal fibroblasts, of chronic GVHD or control mice, was assessed. It was shown that two sequential signals are needed for IL-1 generation by dermal fibroblasts; priming by lymphokines/cytokines followed by a challenge with LPS. A variety of recombinant lymphokines and cytokines (G/M-CSF, IL-2, TNF, IL-1 beta and IFNs alpha, beta and gamma) were shown to be efficient in priming dermal fibroblasts for IL-1 generation. IL-1 activity in dermal fibroblasts, most probably of the IL-1 alpha species, was located in frozen-thawed cell lysates or associated to the cell membrane, though not secreted into the culture fluids. Dermal fibroblasts from chronic GVHD mice manifested a pronounced depression in IL-1 generation upon stimulation with exogenous lymphokines/cytokines and LPS. This was observed over a wide range of concentrations of lymphokines/cytokines and LPS. The depressed ability of chronic GVHD fibroblasts to generate IL-1 was pronounced even after few passages of the cells in vitro, and upon stimulation in culture outside the suppressive milieu of the animal.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Fibroblastos/metabolismo , Doença Enxerto-Hospedeiro/imunologia , Interleucina-1/biossíntese , Pele/patologia , Animais , Citocinas/farmacologia , Doença Enxerto-Hospedeiro/metabolismo , Doença Enxerto-Hospedeiro/patologia , Linfocinas/farmacologia , Camundongos , Camundongos Endogâmicos AKR , Camundongos Endogâmicos BALB C/imunologia , Camundongos Endogâmicos C57BL/imunologia , Proteínas Recombinantes/farmacologia , Pele/metabolismoRESUMO
Several clones of neuroblastoma-glioma NG108-15 hybrid cells were used to reveal whether the regulation of opiate receptor density interacts with the regulation of alpha-adrenergic or acetyl-choline receptors. Low density of alpha-adrenergic receptors in 3 selected clones was accompanied with similar reduction in the density of enkephalin receptors but not in muscarinic acetyl-choline receptors. Yet opiate antagonists that increased the number of opiate receptors in the parent NG108-15 cells in a stereospecific manner had no similar effect on the number of alpha-adrenergic receptors. Moreover, the stable enkephalin analogue D-ala-2-methionine enkephalinamide, but not the opiate alkaloid morphine, decreased the binding of 3H-DAMEA to the membranes and induced down-regulation of enkephalin receptors. Yet DAMEA had no effect on the binding of the alpha-adrenergic antagonist 3H-yohimbine. The study suggests that alpha-adrenergic and enkephalin receptors may share some common regulatory pathways but opiate peptides and antagonists selectively decrease or increase the density of enkephalin receptors, respectively, with no effect on alpha-adrenergic receptor density.
Assuntos
Receptores Adrenérgicos alfa/fisiologia , Receptores Adrenérgicos/fisiologia , Receptores Opioides/fisiologia , Animais , Endorfinas/farmacologia , Células Híbridas , Técnicas In Vitro , Entorpecentes/farmacologia , Receptores Colinérgicos/fisiologia , Receptores Muscarínicos/fisiologiaRESUMO
Self-reported postoperative pain was reduced significantly (P less than .05) for up to six hours in a group of ambulatory surgical patients with the application of 5 mL of 1% etidocaine to the banded portion of each fallopian tube after laparoscopic tubal ligation with Falope Rings in comparison to a control group receiving normal saline. The etidocaine group had less nausea and vomiting and smaller antiemetic and analgesic requirements than did the control group, though those results were not statistically significant.
PIP: The results of a randomized, double-blind, clinical trial suggest that topical etidocaine can significantly reduce postoperative pain when applied to the fallopian tubes after tubal banding. The 97 study subjects were woman admitted to a New York clinic in 1985-87 for same- day laparoscopic tubal ligation with Falope rings. All patients received general anesthesia and underwent the standard 2-puncture laparoscopic technique. In the 46 cases, 5 mL of 1% etidocaine was applied to the banded portion of each fallopian tube after ligation. In the 41 controls, normal saline was administered to the tubes. Patients were asked to rate their postoperative pain on a scale from 0 (no pain)- 10 (worse pain ever experienced) at 3 intervals: 2 hours after return from the recovery room, at the time of hospital discharge, and 24 hours after discharge. Mean analog pain scores were significantly lower in the etidocaine group than the placebo group after return from the recovery room and the time of discharge (p0.05); there was no significant differences between the 2 groups 24 hours after discharge in terms of pain level. Women who received etidocaine also required less medication for postoperative nausea and vomiting (24%) than controls (37%), but this difference was not significant. Finally, a smaller percentage of women from the etidocaine group required parenteral or oral analgesics postoperatively (74% compared with 95% of the controls). Application of etidocaine to the banded tubes took only 2-3 minutes and was easily learned by the operating gynecologists.
Assuntos
Acetanilidas/administração & dosagem , Etidocaína/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Esterilização Tubária , Administração Tópica , Adulto , Procedimentos Cirúrgicos Ambulatórios , Tubas Uterinas , Feminino , Humanos , Período Intraoperatório , Laparoscopia , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Intramural hematoma of the aorta is a fatal disorder that remains poorly characterized. Recently, it has been accepted as a variant form of aortic dissection, where blood accumulates within the aortic media without the presence of an intimal tear. Clinically, it may present somewhat similar to dissection, and although optimal therapy remains controversial, current opinion supports surgery as the preferred method of treatment for intramural hematomas that involve the ascending aorta and aortic arch.
Assuntos
Doenças da Aorta/diagnóstico , Tamponamento Cardíaco/etiologia , Hematoma/diagnóstico , Idoso , Doenças da Aorta/complicações , Doenças da Aorta/patologia , Doenças da Aorta/fisiopatologia , Doenças da Aorta/cirurgia , Aortografia/métodos , Pressão Sanguínea , Implante de Prótese Vascular , Cateterismo Cardíaco , Tamponamento Cardíaco/patologia , Tamponamento Cardíaco/fisiopatologia , Tamponamento Cardíaco/cirurgia , Pressão Venosa Central , Ecocardiografia Transesofagiana , Hematoma/complicações , Hematoma/patologia , Hematoma/fisiopatologia , Hematoma/cirurgia , Humanos , Masculino , Pericardiectomia , Artéria Pulmonar/fisiopatologia , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Hypnosis has many applications in the field of reproductive health care. This paper describes its use in the treatment of sexual dysfunction, urinary incontinence, chronic pelvic pain, hyperemesis gravidarum, and pain relief in labor and delivery. Four case reports are used for illustration. Misconceptions about the risks and benefits of hypnosis are discussed. Information about training for clinicians in hypnosis is described.
Assuntos
Ginecologia , Hipnose/métodos , Obstetrícia , Técnicas Reprodutivas , Adolescente , Adulto , Feminino , Humanos , MasculinoRESUMO
Normal human skin fibroblasts secrete most of their hexosaminidase (Hex) into the medium upon incubation with 10(-4) imipramine, while preincubation with 2.5 X 10(-9) M dexamethasone prevents this effect. These results support the hypotheses that 1) treatment of psychotic Hex A deficient patients with amphiphilic antidepressants (such as imipramine) aggravates the patients' disease through depletion of their residual cellular Hex A, and 2) concomitant medication with dexamethasone may mitigate this drug-induced deleterious effect.