The categorical and dimensional models of endogenous depression

We calculated a Research Diagnostic Criteria (RDC) endogenous score for 257 depressed inpatients based on the number of endogenous criteria present. The distribution of RDC endogenous scores was unimodal. There was no association between endogenous scores and results of the Dexamethasone Suppression Test, or morbid risk for depression in the patients' first-degree relatives. The morbid risk for a family history of alcoholism tended to decrease with increasing endogenous scores, although a consistent steady decline was not observed. The results suggest that the RDC criteria do not fit either the categorical or dimensional model of endogenous classification. Potential sources of difficulty with the RDC endogenous criteria are discussed.     

Comorbid psychiatric disorders in depressed outpatients: demographic and clinical features

BACKGROUND: This study evaluated the clinical and sociodemographic features associated with various degrees of concurrent comorbidity in adult outpatients with nonpsychotic major depressive disorder (MDD). METHODS: Outpatients enrolled in the STAR*D trial completed the Psychiatric Diagnostic Screening Questionnaire (PDSQ). An a priori 90% specificity threshold was set for PDSQ responses to ascertain the presence of 11 different concurrent DSM-IV Axis I disorders. RESULTS: Of 1376 outpatients, 38.2% had no concurrent comorbidities, while 25.6% suffered one, 16.1% suffered two, and 20.2% suffered three or more comorbid conditions. Altogether, 29.3% met threshold for social anxiety disorder, 20.8% for generalized anxiety disorder, 18.8% for posttraumatic stress disorder, 12.4% for bulimia, 11.9% for alcohol abuse/dependence, 13.4% for obsessive-compulsive disorder, 11.1% for panic disorder, 9.4% for agoraphobia, 7.3% for drug abuse/dependence, 3.7% for hypochondriasis, and 2.2% for somatoform disorder. Those with more concurrent Axis I conditions had earlier ages at first onset of MDD, longer histories of MDD, greater depressive symptom severity, more general medical comorbidity (even though they were younger than those with fewer comorbid conditions), poorer physical and mental function, health perceptions, and life satisfaction; and were more likely to be seen in primary care settings. LIMITATIONS: Participants had to meet entry criteria for STAR*D. Ascertainment of comorbid conditions was not based on a structured interview. CONCLUSIONS: Concurrent Axis I conditions (most often anxiety disorders) are very common with MDD. Greater numbers of concurrent comorbid conditions were associated with increased severity, morbidity, and chronicity of their MDD.     

Primitive Neuroectodermal Tumors of the Central Nervous System

Controversial issues relating to the pathobiology and classification of central nervous system primitive neuroectodermal tumors (PNETs) have plagued neuropathologists for more than 70 years. Hypotheses advanced in the mid-1920's have remained as fixed concepts in contemporary literature, largely consequent to repetitious support by a small number of neuropathologists despite a growing body of information discrediting these ideas from neuroembryologists, oncologists, neuroscien-tists and pathologists.
Attention has largely focused upon PNETs arising in the cerebellum (commonly known as medul-loblastomas [MBs]), because about 80% of central nervous system (CNS) PNETs originate in this site. It has been asserted that the 20% which do not are biologically different, although most individuals agree that the histological features of PNETs that occur in different sites throughout the CNS are indistinguishable from those growing in the cerebellum.
The historical aspects of this controversy are examined in the face of evidence that there is, in fact, a unique class of CNS tumors which should appropriately be regarded as primitive neuroectodermal in nature. Specifically, a number of different approaches to the problem have yielded data supporting this hypothesis. These approaches include the identification of patterns of expression among a variety of cellular antigens (demonstrated by the use of immunopathological techniques), molecular analyses of cell lines derived from these tumors, experimental production of PNETs and molecular genetic analyses.
Differences of opinion among surgeons, oncologists and radiotherapists are typically resolved by conducting cooperative studies of patients with these tumors who are diagnosed and treated at multiple centers.     

Interaction of toxic venoms with the complement system

Thirty-nine venoms from various vertebrate and invertebrate species were tested for their ability to consume haemolytic complement (C) activity upon incubation in fresh guinea-pig serum. Nineteen had `anti-complementary' activity, and these were provisionally sorted into the following groups: Pattern I—exemplified by the Naja haje (Egyptian cobra) and six other Elapidae species (all cobras), which induced selective consumption of C3—C9, and led to formation of a stable C3—C9-consuming intermediate; Pattern II—exemplified by the Agkistrodon rhodostoma (Malayan pit viper), Bitis arietans (puff adder), Bothrops jararaca (South American pit viper), Bothrops atrox (Fer de Lance) and three other species, which induced marked consumption of C4 and C2, as well as C3—C9, but did not form a stable C3—C9-consuming intermediate; and individual animals, e.g. the Lachesis muta (bushmaster), which induced other patterns (III—VI) of complement component consumption. Active fractions of representative venoms were partially purified by ion exchange and gel filtration chromatography and their interactions with the complement system characterized further. It is anticipated that these enzymes, with a capacity to activate the complement system in unique ways, will prove to be of further experimental usefulness.     

Striking a balance: inter-kingdom cell-to-cell signaling,friendship or war?

There is a growing body of evidence suggesting that bacterial signaling molecules are involved in cross-kingdom communication with eukaryotic cells. Bacterial signaling molecules can enter eukaryotic cells and appear to modulate immune responses to bacterial pathogens. Recently, an enticing study demonstrated that mammalian airway epithelial cells have the ability to inactivate these bacterial signaling molecules, suggesting that this activity might have a role in the host innate response against bacterial infections.