Comparative study of major lipid constituents in human and monkey aorta

The contents of total lipids, phospholipids, cholesterol, triglyceride and free fatty acid in intima and media of thoracic and abdominal segments of aorta from normal human subjects and rhesus monkeys were determined. An increase in total lipids in intima as compared to that of media was noted in both species. A comparison of lipid contents of thoracic and abdominal segments from both species revealed that abdominal segment contained significantly greater lipid. Further, human thoracic and abdominal aortic intima and media had higher content of cholesterol as compared to that of monkey aorta. The differences in lipid profile in aorta of these two species have been highlighted to provide a clue with respect to the differences in the prevalence and morphology of atherosclerosis as seen in monkey and man.     

Single treatment (hormonal imprinting) of newborn rats with serotonin increases the serotonin content of cells in adults

Hormonal imprinting takes place perinatally at the first encounter between the hormone and its target receptor, causing the finishment of the maturation of receptor-signal transduction system. In the presence of an excess of the target hormone or related molecules faulty imprinting develops with life-long consequences. In earlier experiments single neonatal treatment with minute dose of IL-6 caused also prolonged stimulation of IL-6 production. In the present experiment newborn female and male rats were treated with 20 microg serotonin (hormonal imprinting) and were studied for serotonin content of different cell types in adult age. Serotonin content was measured by flow cytometry and its localization was determined by confocal microscopy. Serotonin content was detected in white blood cells (lymphocytes, monocytes and granulocytes); in lymphocytes, monocytes (macrophages), granulocytes and mast cells of peritoneal fluid and thymic lymphocytes. Serotonin was present in all cell types of control animals studied. Serotonin content extremely elevated in the white blood cells and also increased in the peritoneal cells of neonatally treated female animals. There was no elevation in thymic lymphocytes. The mean values of male animals remained at the control level. The experiments call attention to the life-long effect of the perinatal hormonal imprinting manifested presently in the elevation of serotonin content and point to the gender differences of serotonin imprinting. Considering the role of serotonin in mood and psychiatric diseases, the observations could have some clinical importance.     

Recurrent inhibition of human firing motoneurons (experimental and modeling study)

Recurrent inhibition between tonically activated single human motoneurons was studied experimentally and by means of a computer simulation. Motor unit activity was recorded during weak isometric constant-force muscle contractions of brachial biceps (BB) and soleus (SOL) muscles. Three techniques (cross correlogram, frequencygram, and interspike interval analysis) were used to gauge the relations between single motor unit potential trains. Pure inhibition was detected in 5.6% of 54 BB motoneuron pairs and in 5.2% of 43 SOL motoneuron pairs. In 27.8% (BB) and 23.7% (SOL) presumed inhibition symptoms were accompanied by a synchrony peak; 37% (BB) and 48.8% (SOL) exhibited synchrony alone. The demonstrated inhibition was very weak, at the edge of detectability. Computer simulations were based on the threshold-crossing model of a tonically firing motoneuron. The model included synaptic noise as well as threshold and postsynaptic potential (PSP) amplitude change within interspike interval. Inhibition efficiency of the model neurons increased with IPSP amplitude and duration, and with increasing source firing rate. The efficiency depended on target motoneuron interspike interval in a manner similar to standard deviation of ISI. The minimum detectable amplitude estimated in the simulations was about 50V, which, compared with the experimental results, suggests that amplitudes of detectable recurrent IPSPs in human motoneurons during weak muscle contractions do not exceed this magnitude. Since recurrent inhibition is known to be progressively depressed with an increase in the force of voluntary contraction, it is concluded that the recurrent inhibition hardly plays any important role in the isometric muscle contractions of constant force.     

Comparative and experimental embryogenesis of Plectidae (Nematoda)

Comparative analysis of early embryogenesis indicates that considerable differences exist among nematode species. To better understand to what extent the well-studied development of Caenorhabditis elegans is representative for nematodes in general, we extended our earlier studies to other families of this phylum. Here we report our findings on seven species of Plectidae. We found that Plectidae embryos share a number of developmental similarities with one branch of nematodes (Secernentea), including C. elegans, but not with the other branch (Adenophorea), and thus support conclusions concerning their phylogenetic position drawn from molecular data. However, Plectidae also show developmental differences to other Secernentea, suggesting an early separation from them. Prominent characteristics of Plectidae are (1) strict left-right divisions of somatic founder cells generating a prominent early bilateral symmetry and (2) a very early start of gastrulation with immigration of a single gut precursor cell. To determine whether gastrulation with two gut precursors is crucial for C. elegans embryos, we induced it to gastrulate with a single blastomere like in Plectidae. As this alteration is compatible with an essentially normal subsequent embryogenesis, cleavage of the gut precursor before gastrulation is obviously not required. As major differences exist among nematodes concerning the potential to compensate for eliminated early blastomeres, we tested this feature in one Plectus species. We found that Plectus does not replace a lost cell but behaves like C. elegansin this respect, in contrast to our previous findings in Acrobeloides nanus, another member of the Secernentea.     

The venous territories (venosomes) of the human body: experimental study and clinical implications

The venous architecture of the integument and the underlying deep tissues was studied in six total-body human fresh cadavers and a series of isolated regional studies of the limbs and torso. A radiopaque lead oxide mixture was injected, and the integument and deep tissues were dissected and radiographed. The sites of the venous perforators were plotted and traced to their underlying parent veins that accompany the source (segmental) arteries. A series of cross-sectional studies were made in one subject to illustrate the course of the perforators between the integument and the deep tissues. The veins were dissected under magnification to identify the site and orientation of the valves. Results revealed a large number of valveless (oscillating) veins within the integument and deep tissues that link adjacent valved venous territories and allow equilibration of flow and pressure throughout the tissue. Where choke arteries define the arterial territories, they are matched by boundaries of oscillating veins in the venous studies. The venous architecture is a continuous network of arcades that follow the connective-tissue framework of the body. The veins converge from mobile to fixed areas, and they "hitchhike" with nerves. The venous drainage mirrors the arterial supply in the deep tissues and in most areas of the integument in the head, neck, and torso. In the limbs, the stellate pattern of the venous perforators is modified by longitudinal channels in the subdermal network. However, when an island flap is raised, these longitudinal channels are disconnected, and once again the arterial and venous patterns match. Our venous studies add strength to the angiosome concept. Where source arteries supply a composite block of tissue, we have demonstrated radiologically and by microdissection that the branches of these arteries are accompanied by veins that drain in the opposite direction and return to the same locus. Hence each angiosome consists of matching arteriosomes and venosomes. The clinical implications of these results are discussed with particular reference to the design of flaps, the delay phenomenon, venous free flaps, the pathogenesis of flap necrosis, the "muscle pump," varicose veins, and venous ulceration.     

中药连翘及连翘叶中连翘苷含量的比较研究

用高效液相色谱法对不同产地的连翘叶、老翘、青翘中的连翘苷含量进行测定。结果表明：连翘叶中连翘苷含量比老翘高40倍以上,比青翘中连翘苷含量高2～4倍左右,不同产地的连翘叶、老翘及青翘中连翘苷的含量也有较明显的差别。     

The changing estrogen content of the nuclear fraction of human myometrium during labor

The cytosol and nuclear fractions were prepared from 32 pieces of myometrlum obtained from 20 elective cesarean sections (regarded as typical of quiescent pregnancy (P)) and 12 emergency cesareans (performed after labor had started and therefore taken as typical of labor (L)). The nuclear fraction was purified by standard procedures. All protein-bound estrogen was released from the nuclear fractions, and the released estrogen simultaneously solubilized by denaturation with ethanol. The estriol (E₃) and estradiol (E₂) content of the alcohol solutions were assayed by radioimmunoassay with highly specific antisera for E₃ and E₂. In the L group, average E₃ content was slightly (not significantly) lower, and average E₂ content was significantly (P < 0.005) higher, than in the P group. The E₃/E₂ ratio decreased dramatically (P < 0.001) during this change from P to L.     

Comparative experimental study of cyclacillin and ampicillin]

Cyclacillin was compared with ampicillin by its bacteriostatic efficiency in vitro, chemotherapeutic efficiency in experimental infections of mice and rats and pharmacokinetic characteristics. It was found that cyclacillin was not superior to ampicillin by its antibacterial action. By a number of characteristics it was even significantly inferior. The pharmacokinetic advantages of cyclacillin were not considered significant.     

Comparative study of catalase-peroxidases (KatGs)

Catalase-peroxidases or KatGs from seven different organisms, including Archaeoglobus fulgidus,Bacillus stearothermophilus, Burkholderia pseudomallei, Escherichia coli, Mycobacterium tuberculosis, Rhodobacter capsulatus and Synechocystis PCC 6803, have been characterized to provide a comparative picture of their respective properties. Collectively, the enzymes exhibit similar turnover rates with the catalase and peroxidase reactions varying between 4900 and 15,900 s⁻¹ and 8-25 s⁻¹, respectively. The seven enzymes also exhibited similar pH optima for the peroxidase (4.25-5.0) and catalase reactions (5.75), and high sensitivity to azide and cyanide with IC₅₀ values of 0.2-20 μM and 50-170 μM, respectively. The K_Ms of the enzymes for H₂O₂ in the catalase reaction were relatively invariant between 3 and 5 mM at pH 7.0, but increased to values ranging from 20 to 225 mM at pH 5, consistent with protonation of the distal histidine (pKa approximately 6.2) interfering with H₂O₂ binding to Cpd I. The catalatic k_cat was 2- to 3-fold higher at pH 5 compared to pH 7, consistent with the uptake of a proton being involved in the reduction of Cpd I. The turnover rates for the INH lyase and isonicotinoyl-NAD synthase reactions, responsible for the activation of isoniazid as an anti-tubercular drug, were also similar across the seven enzymes, but considerably slower, at 0.5 and 0.002 s⁻¹, respectively. Only the NADH oxidase reaction varied more widely between 10⁻⁴ and 10⁻² s⁻¹ with the fastest rate being exhibited by the enzyme from B. pseudomallei.