The organization of trigeminotectal and trigeminothalamic neurons in rodents: a double-labeling study with fluorescent dyes

Retrogradely transported fluorescent dyes (fast blue and diamidino-dihydrochloride yellow) were used to compare the distributions of trigeminofugal neurons that project to the superior colliculus and/or the thalamus in three rodent species. The objective was to determine what the projection and collateralization patterns of these trigeminofugal pathways are and whether they are similar among different species. In each anesthetized animal, one dye was injected into the superior colliculus and the other into the topographically congruent area of the thalamus. Counts of the numbers of yellow, blue, and double-labeled neurons were made throughout the trigeminal complex: principalis, pars oralis, pars interpolaris, and pars caudalis. Trigeminothalamic projections were similar in each of the rodent species studied. The densest concentration of retrogradely labeled neurons was in principalis, with substantially fewer neurons in pars interpolaris, and fewer still in pars oralis and pars caudalis. These neurons were generally small and tended to have round or fusiform somata. A common pattern was also noted among the three species for trigeminotectal neurons. Most trigeminotectal projections originated from neurons in pars interpolaris, somewhat fewer from pars oralis, and the fewest from principalis and pars caudalis. These neurons tended to be the largest in each subdivision and were often multipolar. Following paired injections of the tracers, double-labeled neurons were scattered throughout the sensory trigeminal complex and had morphologies characteristic of single-labeled trigeminotectal neurons. Although comparatively few double-labeled neurons were observed in any species, most of those seen were restricted to the ventrolateral portion of pars interpolaris, a position that corresponds to the representation of the vibrissae. These data indicate that, regardless of the rodent species, the vast majority of labeled trigeminal neurons project either to the superior colliculus or the thalamus, but not to both targets. This might be expected on the basis of the very different behavioral roles these structures play. On the other hand, a subpopulation of trigeminal neurons exists (mainly in pars interpolaris) that does project to both the superior colliculus and the thalamus, perhaps because both structures require some of the same somatosensory information to perform their behavioral functions.     

Direct measurement of the conduction velocity of single motor axons in man

The conduction velocity (CV) of single motor axons was measured in the ulnar and median nerve. Stimuli of submaximal intensities were delivered at the wrist and at the elbow using surface electrodes. The responses of single motor units were recorded by tungsten or steel microelectrodes. Changes of the stimulus intensity and of the position of the stimulation electrodes and subtraction of the responses frequently allowed the potential of the same motor unit to be identified following stimulation at both sites and to calculate its axonal CV. In all individuals, axonal CV's from the low to the high velocity range (40 to 63 m/s) could be measured. The method may provide a new approach to the investigation of various disorders of the peripheral nerve.     

Impairment of polymorphonuclear leukocyte function and metabolic control of diabetes.

OBJECTIVE--In this study, ingestion of Staphylococcus aureus and "bacteria killing" (BK) were measured to evaluate polymorphonuclear leukocyte (PMN) phagocytic functions and chemiluminescence response (CL) to phorbol-myristic acetate (PMA) as respiratory burst activity with regard to metabolic control parameters in diabetic patients. RESEARCH DESIGN AND METHODS--PMN phagocytic functions were assessed in 40 diabetic patients, all receiving insulin and in poor metabolic control, with 3H-thymidine-labeled Staphylococcus aureus in a modified radiometric assay. Bacteria killing was determined by pure-plate counting of surviving bacteria (colony-forming units [cfu]) and luminol-enhanced CL in response to PMA as a measure of respiratory burst. PMN function data were correlated to HbA1 as parameter of recent metabolic control. RESULTS--PMN of diabetic patients showed a significant reduction in Staphylococcus aureus (50.7 +/- 4.1%) and BK (29.4 +/- 4.2%) compared with healthy nondiabetic control subjects (76.6 +/- 4.6% and 16.3 +/- 3.1%, respectively, P less than 0.001), and PMN CL response was markedly reduced in diabetic patients also. Linear regression analysis showed a highly significant negative correlation of HbA1 versus Staphylococcus aureus (r = -0.67, P = 0.001) and a positive correlation for BK (r = 0.73, P less than 0.001). This was also true for CL, although this did not reach statistical significance (P = 0.06). CONCLUSIONS--The data obtained demonstrate impaired PMN phagocytic functions and CL response in diabetic patients. These findings suggest inhibitory effects of elevated glucose concentrations on PMNs, a possible role of protein glycosylation for impairing PMN function, thus contributing in part to altered host defense.     

Association between childhood trauma and physical disorders among adults in the United States

BACKGROUND: The goal of this investigation was to determine the association between self-reported childhood trauma and physical disorders among adults in the United States. METHOD: Data were drawn from the National Comorbidity Survey (N=5877). Multiple logistic regression analyses were used to determine the associations between childhood physical abuse, sexual abuse, and childhood neglect and the likelihood of specific physical disorders among adults. RESULTS: Childhood physical abuse, sexual abuse and neglect were associated with a statistically significantly increased risk of a wide range of physical illnesses during adulthood. After adjusting for demographic characteristics, lifetime anxiety and depressive disorders, alcohol and substance dependence, and all types of trauma: results showed that childhood physical abuse was associated with increased risk of lung disease (OR= 1.5 (1.1, 2.2)), peptic ulcer (OR= 1.5 (1.03, 2.2)) and arthritic disorders (OR= 1.5 (1.1, 2.2)); childhood sexual abuse was associated with increased risk of cardiac disease (OR = 3.7 (1.5, 9.4)); and childhood neglect was associated with increased risk of diabetes (OR=2 2 (1.1, 4.4)) and autoimmune disorders (OR =4.4 (1.7, 11.6)). CONCLUSIONS: Consistent with previous work, these results suggest that self-reported childhood trauma is associated with increased risk of a range of physical illnesses during adulthood. Future research that includes replication of these findings using prospectively assessed physical and mental disorders with objectively measured biological data using a longitudinal design, including other known risk factors for these diseases and more detailed information on specific forms of abuse, is needed to understand the potential mechanisms of these links.     

The topologic and chronologic patterns of hematopoietic cell seeding in host femoral bone marrow after transplantation.

The early stages of homing, seeding, and engraftment of hematopoietic stem and progenitor cells are poorly characterized. We have developed an optical technique that allows in vivo tracking of transplanted, fluorescent-tagged cells in the host femurs. In this study we used fluorescence microscopy to monitor the topologic and chronologic patterns of hematopoietic cell seeding in the femoral bone marrow (BM) of mice. PKH-labeled cells homed to the femur within minutes after injection into a peripheral vein. Most cells drifted within the marrow space and gradually seeded in clusters close to the endosteal surface of the epiphyseal cortex. Three days after transplantation 85% to 94% (14%) of PKH-labeled cells in the femoral marrow were located within 100 microm of the epiphyseal bone surface (P <.001 versus the more central cells), whereas labeled cells were absent in the femoral diaphysis. Primary seeding of juxtaendosteal, epiphyseal marrow occurred independently of recipient conditioning (myeloablated and nonconditioned hosts), donor-recipient antigen disparity, or the phenotype of the injected cells (whole BM and lineage-negative cells) and was consistently observed in secondary recipients of BM-homed cells. Seeding in regions close to the epiphyseal bone was also observed in freshly excised femurs perfused ex vivo and in femurs assessed without prior placement of optical windows, indicating that the site of primary seeding was not affected by surgical placement of optical windows. Four to 5 days after transplantation, cellular clusters appeared in the more central regions of the epiphyses and in the diaphyses. Centrally located cells showed decreased PKH fluorescence, suggesting that they were progeny of the seeding cells, and brightly fluorescent cells (quiescent first-generation seeding cells) were observed close to the bone surface for as long as 24 days after transplantation. These data indicate that the periphery of the femoral marrow hosts primary seeding and that quiescent cells continue to reside in the periphery for weeks and do not divide. The site of proliferation of transplanted cells is the center of the marrow space.     

Development of methods to analyse transcranial Doppler ultrasound signals recorded in microgravity

During space flights, several clinical syndromes may be the result of changes in cerebral circulation. The purpose of the paper is to describe the development and initial evaluation of a system for recording, processing and displaying transcranial Doppler ultrasound (TCD) waveforms from the middle cerebral artery (MCA) in microgravity. Volunteers were repeatedly subjected to 15–20 s intervals of microgravity (‘near zero gravity’) during flights on the KC-135 military aircraft. Continuous TCD recordings from the MCA were stored on magnetic tape. The paper describes the system that was developed to digitise the Doppler ultrasound data and markers that corresponded to the various levels of microgravity, obtain the maximum and mean Doppler waveforms, identify the waveforms and quantify them. The results demonstrate the feasibility of making TCD recordings in a microgravity environment and illustrate excellent performance of the system and its ease of operation. Quantitative waveform analysis of the recordings from the first subject studied in the supine position showed statistically significant changes in MCA velocity waveforms during microgravity.     

Cutaneous stimulation evokes long-lasting excitation of spinal interneurons in the turtle

1. We demonstrated multisecond increases in the excitability of the rostral-scratch reflex in the turtle by electrically stimulating the shell at sites within the rostral-scratch receptive field. To examine the cellular mechanisms for these multisecond increases in scratch excitability, we recorded from single cutaneous afferents and sensory interneurons that responded to stimulation of the shell within the rostral-scratch receptive field. A single segment of the midbody spinal cord (D4, the 4th postcervical segment) was isolated in situ by transecting the spinal cord at the segment's anterior and posterior borders. The isolated segment was left attached to its peripheral nerve that innervates part of the rostral-scratch receptive field. A microsuction electrode (4-5 microns ID) was used to record extracellularly from the descending axons of cutaneous afferents and interneurons in the spinal white matter at the posterior end of the D4 segment. 2. The turtle shell is innervated by slowly and rapidly adapting cutaneous afferents. All cutaneous afferents responded to a single electrical stimulus to the shell with a single action potential. Maintained mechanical stimulation applied to the receptive field of some slowly adapting afferents produced several seconds of afterdischarge at stimulus offset. We refer to the cutaneous afferent afterdischarge caused by mechanical stimulation of the shell as "peripheral afterdischarge." 3. Within the D4 spinal segment there were some interneurons that responded to a brief mechanical stimulus within their receptive fields on the shell with short afterdischarge and others that responded with long afterdischarge. Short-afterdischarge interneurons responded to a single electrical pulse to a site in their receptive fields either with a brief train of action potentials or with a single action potential. Long-afterdischarge interneurons responded to a single electrical shell stimulus with up to 30 s of afterdischarge. Long-afterdischarge interneurons also exhibited strong temporal summation in response to a pair of electrical shell stimuli delivered up to several seconds apart. Because all cutaneous afferents responded to an electrical shell stimulus with a single action potential, we conclude that electrically evoked afterdischarge in interneurons was produced by neural mechanisms in the spinal cord; we refer to this type of afterdischarge as "central afterdischarge." 4. These results demonstrate that neural mechanisms for long-lasting excitability changes in response to cutaneous stimulation reside in a single segment of the spinal cord. Cutaneous interneurons with long afterdischarge may serve as cellular loci for multise     

Modellmyotonie nach 2,4-Dichlorphenoxyacetat (2,4-D) bei der Ratte

Zusammenfassung 1. 2,4-D in einer Dosis, die in vivo Myotonie hervorruft, steigert in vitro am Zwerchfellpräparat die Atmung und die Lactatproduktion, sowohl in einem K- wie auch in einem Nareichen Inkubationsmedium.2. In vivo wurden nach 2,4-D in myotonieerzeugender Dosis G-6-P, F-6-P, FDP, DAP, -GP, Pyruvat und Lactat vermehrt im ruhenden Skeletmuskel (Bauchmuskulatur) gefunden, woraus auf eine gesteigerte Glykolyse geschlossen wurde.3. Kreatinphosphat nahm unter den gleichen Bedingungen wie unter 2. ab. ATP und ADP blieben praktisch unverändert.4. Die unter 1., 2. und 3. erwähnten Befunde werden hypothetisch entweder mit Entkoppelung der oxydativen Phosphorylierung oder einem induzierten bzw. gesteigerten energieverbrauchenden Prozeß in Zusammenhang gebracht. Dabei wäre auch die Kombination dieser beiden energiereduzierenden Prozesse möglich.

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Summary 1. A dose of 2,4-D (which brings about myotonia in vivo), increases O₂-consumption in vitro and increases the production of lactate in potassium as well as sodium rich incubating media.2. In vivo, after a dose of 2,4-D which brought about myotonia, an increase of G-6-P, F-6-P, FDP, DAP, -GP, pyruvate, and lactate was found in the abdominal skeletal muscles at rest. This finding indicated an increase in glycolysis.3. Under the same conditions as in paragraph 2 creatine-phosphate was decreased. ATP and ADP practically unchanged.4. There is a hypothetical connection between the findings mentioned in paragraphs 1, 2 and 3 either in the view of uncoupling of the oxydative phosphorylation or in the view of a process involving an increase in energy consumption. With that, a combination of both energy reducing processes would also be possible.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Morphologic and immunologic evidence of composite B- and T-cell lymphomas. A report of three cases developing in follicular center cell lymphomas

Composite lymphoma (CL) may be defined as two lymphomas, differing as to their cell of origin, that occur simultaneously in the same tissue specimen. While CL usually is indicated histopathologically by at least two morphologically distinct lymphomatous proliferations, the proof that these proliferations are separate and distinct neoplasms requires immunologic analysis. Many so-called cases of CL actually represent the well-known phenomenon of lymphoid transformation, in which there is a small cell and a large cell component in the same specimen. Immunologic studies in these cases have shown that the cytologically distinct neoplastic cells represent different stages in the same cell line. While studying a large series of follicular center cell (FCC) lymphomas, the authors recognized three cases in which there was both morphologic and immunologic evidence of a true CL. Following an initial diagnosis of a nodular FCC lymphoma, rebiopsies from 21 to 62 months later showed the coexistence of a nodular FCC (B-cell) component and a diffuse large cell (T-cell) component.