Alternative wavelengths for sutureless laser microvascular anastomosis: a preliminary study on acute samples

Attempts to improve the speed and patency of microvascular anastomosis with laser-assisted techniques have provided a modest reduction in operative time and comparable success rates. Using sutureless microvascular anastomoses, 30 end-to-end anastomoses were created in the rat carotid artery using the gallium-aluminum-arsenide diode laser (808 nm). Indocyanine green and fibrinogen were applied to enhance tissue absorption of the laser energy and strengthen the bond created. These were compared with previously reported welds using the THC:YAG laser (2150 nm). Mean welding times were 140 and 288 s, and mean bursting pressures immediately after welding were 515 and 400 mmHg for the diode and THC:YAG laser groups, respectively. Histologically, both lateral and vertical spread of thermal damage was limited. Since both lasers create welds of adequate initial strength without stay sutures and are faster and easier to use than existing systems, evaluation of long-term patency would be worthwhile.     

Sound-generating (sonic) motor system in a teleost fish (Porichthys notatus): sexual polymorphisms and general synaptology of sonic motor nucleus

The sonic motor nucleus of the plainfin midshipman, Porichthys notatus, is a midline nucleus located at the junction of the caudal medulla and rostral spinal cord. Its motoneurons innervate sonic "drumming" muscles that are attached to the lateral walls of the swimbladder. There are two classes of sexually mature males referred to as Type I and Type II. The Type I males are larger and generate sounds during the breeding season. The Type II males are smaller and, like adult females, have not yet been shown to generate sounds. This study examined possible sex differences in the size of sonic motoneurons, and the type and distribution of their afferent terminal boutons. The average soma diameter of motoneurons of Type I males is about 50% larger than that of Type II males and females. There is also a small but significant difference in soma diameter between Type II males and females; they are smaller in the former class. There were no sex differences in the presence or distribution of different classes of axosomatic and axodendritic terminal boutons, which included: (1) active zones with either clear, round, or pleomorphic vesicles, (2) active zones with both clear, round vesicles, and larger dense core vesicles, (3) "mixed synapses" with gap junctions and active zones usually associated with pleomorphic vesicles. The results are discussed within the context of sexual differentiation of vertebrate motor systems and the functional organization of the sonic motor system in fishes. Sex differences in soma diameter correlate with a number of sex differences in the gross and ultrastructural features that distinguish the sonic muscles of Type I males from those of Type II males and females, which are similar to each other. The absence of qualitative sex differences in synaptic morphology suggest that the central neuronal circuitry of the sonic motor system is similar among all three adult morphs.     

Stereological study of the developing distal femoral growth plate

The distal femoral growth plate has a uniquely convoluted structure comprised of four mammillate processes. Factors contributing to the development of these processes and overall plate geometry were explored using three-dimensional image analysis of the canine distal femoral epiphysis. The growth plate at birth remains relatively flat until ossification of the epiphysis begins at 1 week of age. Epiphyseal ossification proceeds eccentrically, projecting in the medial-lateral and anterior-posterior directions. Growth plate activity indexed by [3H]thymidine labeling and plate thickness revealed regional differences in cell proliferation. This was measured as a decreased labeling index and thinning of the growth plate in areas capped by the ossifying epiphysis. The eccentric ossification pattern and associated variations in growth plate activity result in definition of an "intraphyseal" groove and medial-lateral oriented sulcus. The groove and sulcus bisect the plate into four quadrants, giving rise to a convoluted structure composed of four areas of plate elevations termed mammillary processes (MP). By 5 weeks, the pattern of ossification results in greater development of the MP in the anterior-medial quadrant and in decreasing order, in the posterior-medial, anterior, and posterior-lateral quadrants. By 10 weeks, a uniform rate of cell proliferation was observed coincident with completion of ossification of the epiphysis. The data suggest that localized variations in growth plate proliferation are associated with ossification of the epiphysis.(ABSTRACT TRUNCATED AT 250 WORDS)     

The biology and tumour-related properties of monocyte tissue factor

Tissue factor (TF, coagulation factor III, CD142) is not only the main physiological initiator of normal blood coagulation, but is also important in the natural history of solid malignancies in that it potentiates metastasis and angiogenesis and mediates outside-in signalling. TF is expressed constitutively by many tissues which are not in contact with blood and by other cells upon injury or activation; the latter include endothelial cells, tissue macrophages, and peripheral blood monocytes. It can exist encrypted and unavailable functionally in the plasma membrane and the appearance of functional TF may be due to synthesis and/or de-encryption. Inflammatory cells often express TF and act to induce its production or de-encryption by other cells locally and, apparently, at remote sites. Inappropriate expression of TF by endothelial cells, macrophages or monocytes is thought to be an important trigger of coagulation in various pathological conditions. Several studies have shown that measurements of monocyte TF (mTF) may provide clinically significant information, particularly in patients with malignant and inflammatory diseases.     

Zur Eliminationskinetik des Digoxin vor und während Spironolactonbehandlung

Zusammenfassung Im Tierversuch konnte unter hohen Spironolactondosen eine Beschleunigung der Digoxinelimination nachgewiesen werden, die auf eine vermehrte Metabolisierung des Digoxins nach Induktion mikrosomaler Leberenzyme zurückgeführt wurde. Deshalb wurde bei 8 Patienten die Eliminationskinetik des Digoxins vor Spironolactonbehandlung untersucht, wobei morgens nüchtern 0,1 mg³H-Digoxin intravenös als einmalige Dosis verabreicht wurde. Zur Messung der Digoxinkonzentration wurden venöse Blutproben zu bestimmten Zitpunkten bis zu 120 h entnommen, der Urin fraktioniert 5 Tage lang gesammelt. Zusätzlich wurde während der gesamten Versuchsperiode die im Stuhl ausgeschiedene Digoxinmenge bestimmt. Während der Messung der Digoxinelimination wurden gleichzeitig nicht-invasive Parameter des mikrosomalen Leberenzymsystems wie Antipyrinhalbwertszeit, Antipyrinclearance, Gamma-Glutamyl-transpeptidase im Blut und d-Glucarsäureausscheidung im 24 h-Urin gemessen. Danach wurde jedem Patienten 15 Tage lang eine therapeutische Erhaltungsdosis von 150 mg Spironolacton täglich verabreicht. 10 Tage nach Beginn der Spironolactonbehandlung wurde die oben beschriebene Untersuchung der Digoxinelimination zusammen mit den Parametern des mikrosomalen Leberenzymsystems wiederholt.Aufgrund der errechneten pharmakokinetischen Parameter ließen sich unter Spironolactonbehandlung keine Änderungen der globalen Eliminationskonstante respektive der Halbwertszeit des Digoxins nachweisen. Ebenso blieb das Verteilungsvolumen, die renale und metabolische Clearance unbeeinflußt, die Digoxinausscheidung im Faeces war während beiden Versuchsperioden nicht signifikant verschieden und betrug für die gemessene Zeitperiode etwa 15% der verabreichten Dosis. Außerdem zeigten die Parameter des mikrosomalen Enzymsystems der Leber keinerlei Änderungen vor und unter Spironolactonbehandlung. Aufgrund dieser Ergebnisse konnte unter den klinisch üblichen Spironolactondosen keine Veränderung der Digoxinelimination nachgewiesen und eine Enzyminduktion sicher ausgeschlossen werden. Deshalb sind die in der Literatur berichteten Änderungen der Digoxinausscheidung auf eine zu hohe Dosierung im Tierversuch zurückzuführen und haben für den Menschen keine therapeutische Bedeutung.Herrn Prof. Dr. E. Bauereisen zum 65. Geburtstag in Dankbarkeit gewidmet     

Neutrophil responses to platelet-activating factor

1-O-Alkyl-2-O-acetyl-sn-glyceryl-3-phosphorylcholine (i.e., platelet-activating factor) was prepared and confirmed to possess potent platelet aggregating activity. It was also potent in aggregating and degranulating rabbit and human neutrophils. When injected into rabbits, the lipid induced profound neutropenia, thrombocytopenia, and anaphylactic symptoms. The lyso derivative of this lipid, 1-O-alkyl-sn-glyceryl-3-phosphorylcholine, was inactive or several orders of magnitude weaker in inducing these responses. The acetylated lipid appears to be a potent stimulator of both platelets and neutrophils. Its anaphylactic-like toxicity may be related, at least in part, to its ability to aggregate or otherwise stimulate these cells.This work was supported by NIH grants AI09169, AI10732, AI14929, HL16769, HL14164, and AMI1799.     

Relation of impaired lymphocyte proliferative function to other major human immunodeficiency virus type 1-induced immunological changes.

Human immunodeficiency virus (HIV) type 1 (HIV-1) induces impairment of immune function reflected in reduced lymphocyte proliferative responses. Many other immune changes are induced by HIV-1, but their relationship to lymphocyte functional defects is not known. The present study was designed to correlate functional defects with other HIV disease parameters. Cryopreserved samples from 118 HIV-1-positive subjects and 40 seronegative individuals were examined. The main findings were that impaired proliferative responses to mitogens correlated with (i) decreased cell surface expression of the interleukin-2 receptor (CD25), (ii) increased expression of HLA-DR antigens on CD4 cells, (iii) reduced CD4 and increased CD8 cell numbers, and (iv) increased levels of serum immune complex dissociated p24 antigen. However, impaired function was not associated with increased serum neopterin, beta2-microglobulin, or soluble interleukin-2 receptor or with CD38 antigen expression on lymphocytes. In summary, proliferative functional impairment correlated with some, but not all, immunological changes associated with HIV-1 infection. Most of the phenotypic markers that correlated with altered function are cell surface molecules with significant roles in lymphocyte proliferation and were associated primarily with CD4 cells, compatible with the view that dysregulation of CD4 cells is responsible for impaired function.     

M. Quadriceps femoris of Man,a muscle with an unusual enzyme activity pattern of energy supplying metabolism in mammals

1. The following enzyme activities were estimated in needle-biopsy samples of the lateral part of the human quadriceps femoris muscle: triosephosphate dehydrogenase (TPDH), lactate dehydrogenase (LDH), NAD : glycerol-3-phosphate dehydrogenase (GPDH), hexokinase (HK), NAD: malate dehydrogenase (MDH), citrate synthase (CS) and hydroxyacyl-CoA dehydrogenase. 2. Although the enzyme activities in muscles of women were lesser than in those of men, no difference was found in the calculated enzyme activity ratios. There is thus no sex-dependent metabolic type-differentiation in this muscle. 3. The human quadriceps femoris is a low-activity muscle, in comparison with muscles of homoiotherm laboratory animals. The enzyme activity ratio of TPDH to CS, characterizing the glycolytic pyruvate formation to aerobic oxidative capacities, shows this muscle to be of an intermediate type in this respect, similarly as the extensor digitorum longus of the rat. The relatively very high capacity of glucose phosphorylation (HK), the high aerobic regeneration of cytoplasmic dehydrogenated NAD (GPDH) and the very low anaerobic regeneration (LDH), show the unusually high proportion of carbohydrates (glucose) which can be broken down aerobically.     

Somatization among older primary care attenders

BACKGROUND: The importance of somatization among older primary care attenders is unclear. We aimed to establish the prevalence, persistence and associations of somatization among older primary care attenders, and the associations of frequent attendance. METHOD: One hundred and forty primary care attenders over 65 years were rated twice, 10 months apart, on measures of somatization, psychiatric status, physical health and attendance. RESULTS: The syndrome of GMS hypochondriacal neurosis had a prevalence of 5% but was transient. Somatized symptoms and attributions were persistent and associated with depression, physical illness and perceived poor social support. Frequent attenders (top third) had higher rates of depression, physical illness and somatic symptoms, and lower perceived support. CONCLUSION: Somatization is common among older primary care attenders and has similar correlates to younger primary care somatizers. Psychological distress among older primary care attenders is associated with frequent attendance. Improved recognition should result in benefits to patients and services.