Gain- and loss-of-function Lyn mutant mice define a critical inhibitory role for Lyn in the myeloid lineage.

To investigate the role of the Lyn kinase in establishing signaling thresholds in hematopoietic cells, a gain-of-function mutation analogous to the Src Y527F-activating mutation was introduced into the Lyn gene. Intriguingly, although Lyn is widely expressed within the hematopoietic system, these mice displayed no propensity toward hematological malignancy. By contrast, analysis of aging cohorts of both loss- and gain-of-function Lyn mutant mice revealed that Lyn(-/-) mice develop splenomegaly, increased numbers of myeloid progenitors, and monocyte/macrophage (M phi) tumors. Biochemical analysis of cells from these mutants revealed that Lyn is essential in establishing ITIM-dependent inhibitory signaling and for activation of specific protein tyrosine phosphatases within myeloid cells. Loss of such inhibitory signaling may predispose mice lacking this putative protooncogene to tumorigenesis.

"Emergency" granulopoiesis in G-CSF-deficient mice in response to Candida albicans infection.

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein believed to play an important role in regulating granulopoiesis both at steady state and during an "emergency" situation. Generation of G-CSF and G-CSF receptor-deficient mice by gene targeting has demonstrated unequivocally the importance of G-CSF in the regulation of baseline granulopoiesis. This study attempted to define the physiologic role of G-CSF during an emergency situation by challenging a cohort of wild-type and G-CSF-deficient mice with Candida albicans. Interestingly, after infection, G-CSF-deficient mice developed an absolute neutrophilia that was observed both in blood and bone marrow. In addition, 3 days after Candida infection increased numbers of granulocyte-macrophage (GM) and macrophage (M) progenitors were observed in the bone marrow of G-CSF-deficient mice. Of the cytokines surveyed, interleukin (IL)-6 levels in serum were elevated; interestingly, levels of IL-6 were higher and more sustained in G-CSF-deficient mice infected with C albicans than similarly infected wild-type mice. Despite the higher levels of serum IL-6, this cytokine is dispensable for the observed neutrophilia because candida-infected IL-6-deficient mice, or mice simultaneously deficient in G-CSF and IL-6, developed neutrophilia. Similarly, mice lacking both G-CSF and GM-CSF developed absolute neutrophilia and had elevated numbers of GM and M progenitors in the bone marrow; thus, G-CSF and GM-CSF are dispensable for promoting the emergency response to candidal infection. (Blood. 2000;95:3725-3733)

Polarity of the first episode, clinical characteristics, and course of manic depressive illness: a systematic retrospective investigation of 320 bipolar I patients.

In 320 patients with established bipolar I disorder, we examined the past course on the basis of polarity at onset (depressive, mixed, and manic). Despite the obvious limitations of retrospective methodology, information on course parameters in a large sample of affective disorders is most practically obtained by such methodology. We believe that our systematic interview of patients and their relatives--as well as the systematic study of their records--minimized potential biases. Depressive onsets were the most common, accounting for 50%, followed by mixed and manic onsets in about equal proportion. In general, the polarity of episodes over time reflected polarity at onset. Those with depressive onset had significantly higher levels of rapid cycling, as well as suicide attempts, but were significantly less likely to develop psychotic symptoms. Mixed onsets, too, had high rates of suicide attempts, but differed from depressive onsets in having significantly more chronicity yet negligible rates of rapid cycling at follow-up evaluation. Because cases with depressive onset had received significantly higher rates of psychopharmacologic treatment, our data are compatible with the hypothesis that antidepressants may play a role in the induction of rapid cycling. Overall, our data support the existence of distinct longitudinal patterns within bipolar I disorder, which in turn appear correlated with the polarity at onset. In particular, rapid cycling and mixed states emerge as distinct psychopathologic processes.

Chronic mania. Family history, prior course, clinical picture and social consequences.

BACKGROUND: Mania with chronic course has been overlooked in the recent literature. Our aim was clinically to characterise and validate this form of mania. METHOD: We evaluated 155 people with DSM-III-R mania and assessed their family history, temperament, symptomatology and course. We used a semi-structured interview for mood disorders, as well as the Comprehensive Psychopathological Rating Scale and the Scale for the Assessment of Positive Symptoms. RESULTS: Twenty (13%) had a chronic course arising from a background of hyperthymic temperament and recurrent mania, with a deteriorative pattern. Clinically, they were characterised by a significantly high rate of almost constant euphoria, grandiose delusions and related delusions, but had relatively low rates of sleep disturbance, psychomotor agitation and hypersexuality. CONCLUSION: Even with current therapies a significant number of people with bipolar disorders have a deteriorative outcome associated with the gradual disappearance of acute mania with an increase in megalomanic delusions, alienation from loved ones and decreased likelihood of medical and psychiatric care.

Mice lacking both granulocyte colony-stimulating factor (CSF) and granulocyte-macrophage CSF have impaired reproductive capacity, perturbed neonatal granulopoiesis, lung disease, amyloidosis, and reduced long-term survival.

Mice lacking granulocyte colony-stimulating factor (G-CSF) are neutropenic with reduced hematopoietic progenitors in the bone marrow and spleen, whereas those lacking granulocyte-macrophage colony-stimulating factor (GM-CSF) have impaired pulmonary homeostasis and increased splenic hematopoietic progenitors, but unimpaired steady-state hematopoiesis. These contrasting phenotypes establish unique roles for these factors in vivo, but do not exclude the existence of additional redundant functions. To investigate this issue, we generated animals lacking both G-CSF and GM-CSF. In the process of characterizing the phenotype of these animals, we further analyzed G-CSF- and GM-CSF-deficient mice, expanding the recognized spectrum of defects in both. G-CSF-deficient animals have a marked predisposition to spontaneous infections, a reduced long-term survival, and a high incidence of reactive type AA amyloidosis. GM-CSF-deficient mice have a modest impairment of reproductive capacity, a propensity to develop lung and soft-tissue infections, and a similarly reduced survival as in G-CSF-deficient animals. The phenotype of mice lacking both G-CSF and GM-CSF was additive to the features of the constituent genotypes, with three novel additional features: a greater degree of neutropenia among newborn mice than in those lacking G-CSF alone, an increased neonatal mortality rate, and a dominant influence of the lack of G-CSF on splenic hematopoiesis resulting in significantly reduced numbers of splenic progenitors. In contrast to newborn animals, adult mice lacking both G-CSF and GM-CSF exhibited similar neutrophil levels as G-CSF-deficient animals. These findings demonstrate that the additional lack of GM-CSF in G-CSF-deficient animals further impairs steady-state granulopoiesis in vivo selectively during the early postnatal period, expand the recognized roles of both G-CSF and GM-CSF in vivo, and emphasize the utility of studying multiply deficient mouse strains in the investigation of functional redundancy.

Clinical subtypes of bipolar mixed states: validating a broader European definition in 143 cases.

OBJECTIVE: To validate and clinically characterize mixed bipolar states derived from the concepts of Kraepelin and the Vienna School and defined as sustained instability of affective manifestations of opposite polarity--that usually fluctuate independently of one another--in the setting of marked emotional perplexity. METHOD: Our criteria for mixed states represent a modified "user-friendly" operationalization of these classical concepts. We compared 143 mixed state patients, so defined, with 118 DSM III-R manic patients, systematically evaluated with the Semistructured Interview for Depression (SID) in our in-patient and day-hospital facilities. RESULTS: The two groups were comparable from demographic and familial standpoints (including family history for bipolar disorder). Mixed states were predominant in the past history of index mixed patients who were more likely to have experienced stressors and to have attempted suicide; manic and hypomanic episodes were more common in the past history of the index manic patients who, in addition, had more episodes and hospitalizations. Although rates of chronicity and rapid cycling were not significantly different in the two groups, the modal episodes in the mixed states were 3-6 months, and in mania they were less than 3 months. Two thirds of both groups arose from a dysregulated baseline temperamental dysregulation, which in manics, was largely hyperthymic, and in mixed patients, was both hyperthymic and depressive. Of our 143 mixed states, only 54% met the DSM III-R criteria for mixed states (which conformed to "dysphoric mixed mania"); of the remaining, 17.5% could be described as "mixed agitated psychotic depressive states" with irritable mood and flight of ideas, and 26% as "unproductive-inhibited manic" with fatigue and indecisiveness. The family history and course of these "non-DSM III-R" mixed states were essentially similar to DSM III-R mixed states. LIMITATION: Family history could not be obtained blind to clinical status in patients with severe psychotic mood states. CLINICAL RELEVANCE: These data favor the classical European approach to mixed states over the grossly under-inclusive current official diagnostic systems. CONCLUSION: The phenomenology of mixed states is more than the mere superposition of opposite affective symptoms and, in many instances, it represents an expansive-excited phase intruding into a depressive temperament, and a melancholic episode intruding into a hyperthymic temperament.