Deterministic chaos in the hemodynamics of an artificial heart

To analyze the hemodynamic parameters during prosthetic circulation as an entity, non linear mathematical techniques were used. To compare natural and prosthetic circulation, two pneumatically actuated ventricular assist devices were implanted as biventricular bypasses in chronic animal experiments using adult goats to consitute the biventricular bypass complete prosthetic circulation model with ventricular fibrillation. After implantation, these goats were placed in a cage and extubated after waking. All hemodynamic parameters with the natural circulation without biventricular bypass pumping, and the artificial circulation with biventricular bypass pumping under ventricular fibrillation were recorded under awake conditions. By the use of a non linear mathematical technique, the arterial blood pressure waveform was embedded into a four dimensional phase space and projected into three dimensional phase space. The Lyapunov numeric method is used as an adjunct to the graphic analysis of the state space. A phase portrait of the attractor showed a high dimension complex structure, with three dimensional solid torus suggesting deterministic chaos during natural circulation. However, a simple attractor, such as a limit cycle attractor, was observed during artificial circulation. Positive Lyapunov exponents during artificial circulation suggest the lower dimensional chaotic system. Thus, hemodynamic parameters during prosthetic circulation must be carefully controlled when unexpected stimuli are fed from outside.

Evaluation of serum tumor markers in patients with advanced or recurrent breast cancer

Serum CA15-3, CEA, and BCA225 concentrations were determined in 98 patients with advanced or recurrent breast cancer in an attempt to correlate elevation with clinical status. The rate of serum positivity was 68.4% (67/98), 55.1% (54/98), and 43.9% (43/98) for CA15-3, CEA, and BCA225, respectively. After a 4 weeks-interval, a 20% change of tumor marker concentration from the preceding assay correlated significantly with clinical findings. Significant elevation was predictive of new recurrence or tumor regrowth after complete remission, especially in patients with bone metastasis. The 20% change in concentration at 4 weeks was also useful in patients with tumor marker concentrations persistently beneath the cut-off level for positive. Serological evaluation of tumor markers in patients with advanced or recurrent breast cancer should seek to document 20% changes over a 4 week interval.

Chaotic behavior of hemodynamics with ventricular assist system

In order to analyze hemodynamic parameters during left ventricular assistance as an entity and not as decomposed parts, non-linear mathematical techniques were utilized. Pneumatically actuated ventricular assist systems (VAS) were implanted as left heart bypasses in acute animal experiments, using healthy adult mongrel dogs. By the use of the non-linear mathematical technique, the arterial blood pressure waveform (AP) was embedded into the four-dimensional phase space and projected into the three-dimensional phase space. The Lyapunov numerical method was used as an adjunct to the graphical analysis of the state space. The phase portrait of the attractor showed a complex structure; a three dimensional solid torus with a screw type structure as a part, suggesting deterministic chaos in the AP without left ventricular assistance. Positive lyapunov exponents confirmed the existence of chaos. During counterpulsation mode left ventricular assistance, the phase portrait of the attractor showed a more complex structure, and positive Lyapunov exponents suggested a greater dimensional deterministic chaos. However, non-structured patterns were seen in the phase space during internal mode VAS driving, suggesting the possibility of dissipative dynamics in the four dimensional phase space. These results suggest that the cardiovascular system with counterpulsation mode VAS driving is in a homeochaotic state, which is thought to be a flexible and intelligent control system. And there is greater dimensional complex dynamics in the circulatory regulatory system with VAD during internal mode assistance.

Cytology and immunohistochemistry of anaplastic meningiomas in squash preparations. A report of two cases

Cytodiagnosis is a useful adjunct to frozen section diagnosis of brain tumors during surgery and has been applied in many pathology laboratories. Although anaplastic (malignant) meningiomas are not extremely rare tumors, their cytologic features have not been well described. Cytologic details of anaplastic meningioma, papillary meningioma with a fibroblastic component and anaplastic angiomatous meningioma are presented. Papillary meningioma showed atypical cell clusters having a close relation to mature endothelial cells and that corresponded to papillary proliferation. Other cell clusters of this tumor showed an ordinary fibroblastic pattern with coarse cytoplasmic filaments and necrotic changes in the cytoplasm. Anaplastic angiomatous meningioma exhibited loose cell clusters. Some of them had coarse cytoplasmic filaments, and others were similar to epithelial cells in origin. Specific features commonly found in anaplastic meningioma were hyperchromatic and pleomorphic nuclei and cytoplasmic filaments more obscure than those of the benign counterpart. Immunocytochemically the tumor cells in the papillary area of papillary meningioma had a positive reaction to antiserum of vimentin, cytokeratin and S-100 protein. The tumor cells of anaplastic plastic angiomatous meningioma showed intracytoplasmic positivity to antivimentin and anti-epithelial membrane antigen serum.

bcr-abl hybrid messenger RNA in a patient with Philadelphia-negative essential thrombocythemia

We describe a case of Philadelphia-negative essential thrombocythemia in whom bcr-abl hybrid messenger RNA was detected. The patient suffered from frequent splenic infarctions and myelofibrosis. Interestingly, a transformation to acute leukemia which was commonly seen in patients with bcr-abl-positive chronic myelogenous leukemia did not occur until he died from heart failure due to severe anemia 8 years after the diagnosis. The heterogeneity of bcr-abl-positive thrombocythemia is emphasized.

A free smooth muscle graft for a continent urinary conduit in dogs

We constructed a continent, catheterizable urinary conduit using a smooth muscle graft in dogs. One end of an isolated vascularized ileal segment was anastomosed to the bladder dome, and the other end was opened in the abdominal wall. The ileal conduit was tightly encircled with a free seromuscular flap of the ileum in 6 dogs and with a similar flap of colon in 6 other dogs. All smooth muscle grafts were alive 6 months after the operation. Pressure study showed that all but one ileal conduit had a pressure of more than 30 cm of water. Two dogs with a free ileal graft leaked urine when the bladder pressure increased, whereas all dogs with a colonic graft never leaked urine from the stoma. This smooth muscle graft will be available to reinforce the continent action of a plicated or narrowed intestinal tube for a urinary reservoir.

Size-reduced cryopreserved pulmonary valve allograft for an RV-PA conduit: technical modification and functional evaluation

Cryopreserved pulmonary allografts harvested from adults at the time of kidney donation were size reduced and used in two children with pulmonary atresia and ventricular septal defect. A technical modification for the creation of size-reduced pulmonary allograft conduits is described. Postoperative ultrasonic and cineangiographic assessments revealed excellent function of the pulmonary bicuspid valved conduit with a minimal pressure gradient and essentially no regurgitation. Although the long-term fate of cryopreserved bicuspid pulmonary valve and conduit is unknown, this conduit provides excellent handling characteristics that render allograft conduits preferable to synthetic conduits. In addition, the remodeled bicuspid pulmonary allograft conduits have exhibited excellent hemodynamic characteristics and are a reasonable alternative to other types of conduits when an appropriate size allograft is not available.

Endemic occurrence of glomerulonephritis associated with streptococcal impetigo

We report here a case of type 1 mesangiocapillary glomerulonephritis as well as a case of mesangial proliferative glomerulonephritis associated with streptococcal skin infection superimposed on atopic dermatitis. Both were endemic occurrences of postinfectious glomerulonephritis developed after repeated dirty-skin treatments for atopic dermatitis performed by unauthorized individuals under unsanitary conditions. Of 20 patients who were similarly treated and subsequently admitted to our hospital because of skin infection and fever, 8 (40%) showed urinary abnormalities. Four patients had renal dysfunction with acute nephritic onset. Almost all showed a decrease in CH50 values and an increase in levels of antistreptolysin O and IgE. In the 2 cases presented here, the disease eventually regressed in association with improvement of the skin infection. Although the occurrence of postinfectious glomerulonephritis has recently become uncommon, we must take care to note urinary abnormalities as early as possible in order to prevent the progression of glomerulonephritis.

Bisalbumin (fast and slow type) induced by human pancreatic juice

To clarify the relationship of pancreatic juice to bisalbumin, we examined the effects of human pancreatic juice and pancreatic proteolytic enzymes on human serum albumin. Electrophoresis showed that a fast-moving band and an increased component of alpha 1-globulin appeared after incubation of serum with pancreatic juice. These components were shown to be albumins by immunofixation and immunoelectrophoresis. The alpha 1-component increased after incubation of serum with trypsin, and was confirmed as a slow-type albumin by immunoelectrophoresis. Fast-type albumin was observed after incubation of serum with chymotrypsin, and carboxypeptidases A and B. In all patients with pancreatic ascites, the fast- and slow-type albumins were seen in serum and ascitic fluid. Bisalbumins appeared in ascites at higher concentrations than in serum, and disappeared after surgical or conservative treatment. The results demonstrate that human pancreatic juice can produce fast- and slow-type albumins by proteolytic enzymes, and they are seen in patients with pancreatic ascites.

Cytosolic calcium concentration-force relation during contractions in the rabbit femoral artery: time-dependency and stimulus specificity

1. By use of front-surface fluorometry with fura-2-loaded rabbit femoral arterial strips, both the cytosolic Ca2+ concentration ([Ca2+]i) and force were simultaneously monitored. By utilizing the [Ca2+]i-force curves, we were thus able to examine the temporal changes in the relationships between [Ca2+]i and force ([Ca2+]i-force relationship) during contractions induced by a high external K+ solution, noradrenaline (NA) and 5-hydroxytryptamine (5-HT). 2. The 'basic' [Ca2+]i-force relationship of the Ca(2+)-induced contractions was obtained by the cumulative applications of extracellular Ca2+ (0-10 mM) during 118 mM K(+)-depolarization (Ca(2+)-contractions). 3. When each vascular strip was exposed to high external K+ (30 mM K(+)-118 mM K+) solutions, the [Ca2+]i abruptly increased until it reached a peak, and then slightly decreased and eventually reached a steady-state level. The force also rapidly rose to reach a maximum plateau level. The changes in [Ca2+]i were more rapid than those in the force. Thus, the [Ca2+]i-force curves observed during the contractions induced by high+ (30 mM-118 mM) solutions showed a counter-clockwise rotation, over time. The entire curve shifted to the right, in a concentration-dependent manner, as compared with the line of the 'basic' [Ca2+]i-force relationship of the Ca(2+)-contraction. However, the [Ca2+]i-force relationship of the steady-state of contractions induced by the single dose applications of high K+ (30 mM-118 mM) overlapped with the line of the 'basic' [Ca2+]i-force relationship of Ca(2+)-contractions. 4. As references, the levels of [Ca2+]i and the force at rest (without stimulation) and at the steady-state of the contractions induced by a single dose application of 118 mM K+ solution were designated as 0% and 100%, respectively. When the vascular strips were exposed to NA (10(-5) M) and to 5-HT (10(-4) M), the [Ca2+]i abruptly rose, and reached a peak (107.1 +/- 5.8%) and 101.3 +/- 2.8%, respectively) after 1 min and 2 min, respectively (the [Ca2+]i-rising phase), and thereafter declined with a similar time course (the [Ca2+]i-declining phase) until reaching a low steady level (the steady-state phase). The force induced by 10(-5) M NA and 10(-4) M 5-HT reached a peak at 4 min (129%) and at 2 min (115%), respectively, and thereafter gradually declined. In contrast to the similarity in the [Ca2+]i transient between NA and 5-HT, the force induced by NA declined more slowly and reached higher steady levels than that seen with 5-HT. The level of force 20 min after the application of NA and 5-HT was 112% and 72%, respectively.5. In the entire time course of the 5-HT-induced contraction, i.e., in [Ca2+]i-rising, [Ca2+]i-declining and the steady-state phases, the [Ca2+]i-force relation was almost the same as that of the Ca2+-contractions.In the [Ca2+]i-rising phase of NA-induced contraction, the [Ca2+]i-force relation was similar to that of the Ca2+-contractions. However, in the [Ca2+] -declining and the steady-state phases, NA produced a greater force than that expected from a given change in the [Ca2+]i of the Ca2+-contractions, which resulted in a leftward shift of the [Ca2+]i-force relation. The extent of the leftward shift depended on the concentration of NA.6. These results suggest that (1) changes in [Ca2+]i precede changes in the force during the high K+-induced contraction, (2) in the initial [Ca2+]i-rising phase of the contractions induced by NA or by 5-HT, the [Ca2+]i-force relation is similar to that of Ca2+-contractions, and (3) in the subsequent[Ca2+]i-declining and the steady-state phases of the contractions, 5-HT demonstrated little enhancement in force for the given levels of [Ca2+]i, while NA induced a greater force for the given levels of [Ca2+],, in the rabbit femoral artery. Based on the above findings we suggest the presence of a time-dependent and stimulus-specific modulation of the Ca2+ sensitivity in the contractile apparatus of arterial smooth muscles.

Endothelin-1 and endothelin-3 regulate differently vasoconstrictor responses of smooth muscle of the porcine coronary artery

1. Using front-surface fluorometry of fura-2 and medial strips of the porcine coronary artery, we investigated mechanisms by which endothelin-1 (ET-1) and ET-3 function as vasoconstrictors. 2. In the presence of extracellular Ca2+(1.25 mM), ET-1 (10(-10)-10(-7) M) increased cytosolic Ca2+ concentrations ([Ca2+]i) and tension, in a concentration-dependent manner. ET-1, at concentrations greater than 10(-8) M, induced an abrupt elevation of [Ca2+]i which reached a transient peak (the first component, [Ca2+]i-rising phase) and subsequently declined ([Ca2+]i-declining phase) to reach a lower sustained phase (the second component, steady-state phase), while the tension rose monotonically to reach a peak and then slightly and gradually declined. ET-1, at concentrations lower than 10(-8) M, induced slowly developing and sustained increases in [Ca2+]i and tension ([Ca2+]i-rising phase followed by steady-state phase). All concentrations of ET-1 increased tension more slowly than [Ca2+]i. 3. In the presence of extracellular Ca2+, ET-3 (10(-8)-10(-5) M) induced concentration-dependent increases in [Ca2+]i and tension. However, the maximal elevations of [Ca2+]i and tension induced by ET-3 were substantially smaller than those induced by ET-1, indicating the involvement of an ETA receptor subtype. ET-3, at concentrations greater than 6 x 10(-7) M, caused biphasic slowly developing increases in [Ca2+]i and tension. At concentrations lower than 10(-6) M, ET-3 caused monophasic increases in [Ca2+]i and tension. At all concentrations of ET-3, the time courses of increases in [Ca2+]i and tension were similar. 4. The biphasic increases in [Ca2+]i and tension induced by 10-5 M ET-3 and by 1O-7M ET-1 were significantly inhibited by pretreatment with 10-5 M of the Ca2+ entry blocker, diltiazem, although the inhibition of the first component of ET-l-induced [Ca2+]i increase was partial.5. In the absence of extracellular Ca2+, ET-1 induced a concentration-dependent transient increase in[Ca2+]i, possibly due to release of Ca2+ from intracellular stores, and a sustained contraction. In contrast, ET-3 ( 10-6 M) caused little, if any, transient increase in [Ca2+]i and a small sustained contraction.6. Temporal changes in the relationships between [Ca2+]i and tension ([Ca2+]1-tension relationship)during contractions induced by ET-1 and ET-3 were compared with the [Ca2+]i-tension relationship of Ca2+-induced contractions (Ca2+-contractions) obtained by cumulative applications of extracellular Ca2+(0-7.5 mM) to tissues depolarized in the presence of 118 mMK+. In the [Ca2+]i-rising phase, ET-1 increased tension more slowly than [Ca2+]i, thereby shifting the [Ca2+]i-tension relation to the right from that for Ca2+-contractions. In the [Ca2+I-declining and the steady-state phases, ET-1, at concentrations higher than 10-9 M, produced greater tension development than that expected from a given change in[Ca2+ji, resulting in a leftward shift of the [Ca2+]i-tension relation. During ET-3-induced contractions,([Ca2+]i-rising, [Ca2+]i-declining and steady-state phases), the [Ca2+]i-tension relation was similar to that of Ca2+-contractions.7. BQ-123, a selective ETA receptor antagonist, completely inhibited the increases in [Ca2+1]i and tension induced by ET-1 and ET-3.8. These results suggest: (1) That ET-1 elicits vasoconstriction by increasing [Ca2+]i through the activation of Ca2+ influx from the extracellular space and Ca2+ release from intracellular storage sites,and by increasing the Ca2+ sensitivity of the contractile apparatus, whereas ET-3 induces vasoconstriction by increasing [Ca2+1] mainly through Ca2+ influx from the extracellular space. (2) Distinct mechanisms of time-dependent modulation of the Ca2+ sensitivity function in the vasoconstrictor responses to ET-1 and ET-3. (3) That both ET-1- and ET-3-induced contractions seem to be mediated via ETA-receptors in porcine coronary artery, and that the ETA-receptor-mediated effects of ET-1 and ET-3 can be dissociated at the sub-receptor levels of the signal transduction pathway.

Analysis of biological function of poly(ADP-ribosyl)ation in Drosophila melanogaster

To understand the biological function of poly(ADP-ribosyl)ation of proteins, we have isolated and characterized the gene for poly(ADP-ribose) polymerase from Drosophila melanogaster. Two approaches were taken to analyze the function of the poly(ADP-ribosyl)ation reaction. The first is analysis of the homology of the amino acid sequences of poly(ADP-ribose) polymerase from phylogenetically different eukaryotes, namely human, mouse, bovine, chicken, Xenopus laevis and Drosophila melanogaster and elucidation of the conserved amino acid sequences that appear to be important for the function of poly(ADP-ribose) polymerase. Analysis of the recombinant poly(ADP-ribose) polymerase which had truncated or mutated motifs expressed in E coli would confirm the importance of the conserved amino acid sequence. The interaction of poly(ADP-ribose) polymerase with other proteins involved in DNA repair, replication, recombination and transcription will clarify the function of poly(ADP-ribosyl)ation. The second approach is to get the mutants which have disruption in the poly(ADP-ribose) polymerase gene and to analyse the phenotypes of these mutants. The characterization of these mutants will be discussed.

[CT anatomy of the caudate lobe of the liver]

The anatomy of the portal vein branches in the caudate lobe of the liver was studied in 20 patients by double-phase CT arterial portography (DP-CTAP). DP-CTAP provided excellent images of the portal venous system in the first phase and the perfusion defects of intrahepatic tumors in the second phase. From DP-CTAP images of the first phase, a sufficient number of interpolated images were created for a smooth paging display. The ramifying structures of the portal system were traced on the monitor using the tracking ball. This method was found to be very effective and reliable for the anatomical assessment of the caudate lobe. The number and origins of the caudal portal branches were investigated in each case, and the caudate lobe of the liver could be divided into right and left segments.

Hypersensitivity pneumonitis in a pearl nucleus worker

A 37-year-old woman had worked for 4 years in a shell-processing factory where considerable airborne dust was produced cutting and polishing fresh water shells into pearl nuclei. She had a dry cough and dyspnea. Transbronchial lung biopsy showed noncaseating granulomas and cellular intraalveolar infiltrates. High-resolution lung computed tomography (HRCT) showed diffuse small nodules and ground-glass opacities. Hypersensitivity pneumonitis caused by shell dust should be considered in the appropriate clinical setting in a patient with the appropriate radiographic abnormalities.

[An epidemiological study of stroke in a geriatric community--with special reference meteorological factors]

The incidence of cerebrovascular event during a period of 3 years in the geriatric society in Japan was examined along with the alternating pattern of cerebrovascular accidents in relation to aging and seasonal factors. The population of Tsuwano town was approximately 7000. The percentage of aged people over 65-year-old reached 23.1% in the 1990 national census. All cerebrovascular accident patients in our hospital and two outpatients clinic in this city were registered during the period from April, 1990 to March, 1993. The number of patients in the period was 95 cases, of which 19 were classified as transient ischemic attack (TIA), 30 as cerebral thrombosis, 16 as cerebral embolism, 10 as cerebral hemorrhage, 7 as subarachnoid hemorrhage, and 13 as unclassified cerebral infarction. The frequency of each type except TIA was 39.5% cerebral thrombosis, 21.1% cerebral embolism, 13.2% cerebral hemorrhage, and 9.2% subarachnoid hemorrhage. In all cases, hypertension was observed in 62.1%, and past history of cerebrovascular accident was observed in 29.5%. The cerebral embolism group was older than the other groups and one-half of this group had atrial fibrillation. Peak incidence differed by type of illness, TIA and cerebral embolism occurred uniformly throughout the year, but subarachnoid hemorrhage and cerebral thrombosis in the spring. The relationship of cerebrovascular accident to crisis, especially potentiation by cerebral thrombosis was evaluated in light of climatic factors.

Elevated anti-neutrophil cytoplasmic antibody titer in a patient with atypical orbital pseudotumor

We recently examined a patient with ophthalmic manifestations of Wegener's granulomatosis in whom antineutrophil cytoplasmic antibody (cANCA) titers provided helpful diagnostic information. A 40-year-old man who had suffered from bilateral exophthalmos for 9 months was diagnosed initially as having idiopathic inflammatory pseudotumor. The patient exhibited purulent nasal discharge and microhematuria. A histopathologic study revealed vasculitis. His ANCA titer for cANCA was found to be evaluated, and our patient was subsequently diagnosed as having Wegener's granulomatosis. His ocular symptoms resolved and did not recur after treatment with corticosteroid in combination with cyclophosphamide. We believe that cANCA levels should be investigated in patients with orbital pseudotumor as a possible sign of Wegener's granulomatosis.

Free sensory and nonsensory plantar flap transfers in the treatment of ischial decubitus ulcers

For the treatment of ischial decubitus ulcers, a sensory plantar flap is ideal, because the sensory stimulation of the flap appears to contribute greatly to long-term flap viability. When a sensory flap is not possible, a nonsensory plantar flap offers most of the same advantages.

[Effect of blood conservation in open-heart surgery: a comparison of 3 different methods]

Conventional blood conservation techniques have been insufficient to decrease blood transfusion requirement in open-heart surgery. Blood conservation and erythropoietin administration were performed to avoid homologous blood transfusion. Intraoperative autotransfusion has been routinely used in cardiac operations with cardiopulmonary bypass in our hospital. To evaluate the effect of conservation techniques, 286 patients were divided into four groups. In group I (23 patients), autologous whole blood was drawn and saved one to two weeks before operation. In group II (50 patients), erythropoietin preparation was given subcutaneously once a week and autologous blood conservation was also performed in the same manner as group I. In group III (48 patients), intra-operative hemodilutional autologous blood transfusion was performed. In group IV, as a control group (165 patients), only intra-operative autotransfusion was used. Homologous blood transfusion was avoided in 83% of group I patients, in 90% of group II, in 82% of group III, and 29% of group IV. In addition, in group II the hemoglobin value at the time of discharge was significantly higher than those of other groups (p < 0.05-0.01). Thus, conventional blood conservation techniques plus subcutaneous administration of erythropoietin was very effective to increase the rate of "non-blood" open-heart surgery.

In vivo effect of a selective endothelin receptor antagonist, BQ-123, on renal function in cyclosporin A-treated rats

To investigate the possible involvement of endogenous endothelin (ET) in cyclosporin A (CsA) nephrotoxicity, we examined the renal effects of the selective [125I]ET-1 binding to porcine aortic membrane (ETA) receptor antagonist, BQ-123 (BQ), on CsA-treated rats. An osmotic minipump filled with BQ or its vehicle (saline), was subcutaneously implanted and animals were treated with CsA (50 mg/kg/d, i.p.) for 4 d. In both BQ- and its vehicle-treated rats, the 24-hour urine volume, urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion, urinary Ca/creatinine (Cr) and urinary NAG/Cr ratios were significantly increased compared with those before administration of CsA. In contrast, after administration of CsA, urinary Cr excretion was significantly decreased in both rat groups. Although urinary NAG excretion and the NAG/Cr ratio in the rats treated with BQ were significantly increased compared with those treated with saline, the serum Cr levels in BQ-treated rats were significantly lower than those in saline-treated rats. Urinary immunoreactive ET-1 (irET-1) excretion in all animals was significantly increased after administration of CsA. There were no significant differences in urinary irET-1 excretion in both BQ-treated and saline-treated rats with and without CsA. Expression of irET-1 was seen in the cytoplasm of renal tubules, but the degree of expression was similar in the BQ-treated and saline-treated rats on CsA. In the BQ-treated rats, small round areas with high grain densities over the glomeruli in the cortex and vesa recta bundles in the outer medulla were masked by the antagonist action of BQ.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonlinear pharmacokinetics of a recombinant human granulocyte colony-stimulating factor derivative (nartograstim): species differences among rats, monkeys and humans

NTG is a human G-CSF derivative produced by Escherichia coli using gene-engineering techniques. The dose dependency of NTG pharmacokinetics in rats and monkeys was examined and compared with that previously reported for humans. In all species, the total clearance decreased and the mean residence time was prolonged as the intravenously administered dose of NTG was increased. At higher doses, the clearance in each species approached a constant value. This suggests that both saturable and nonsaturable processes are involved in NTG elimination. At the lowest dose, the saturable process accounted for 57% to 76% of total clearance. The plasma concentration-time profiles of NTG in rats and monkeys were analyzed by nonlinear pharmacokinetic models which contained both linear and Michaelis-Menten type elimination from the central compartment. The Km and Vmax values in rat, about 240 pM and 40 pmol/hr/kg, respectively, were comparable to those in the monkey. On the other hand, the values in humans were smaller, about 17% and 7%, respectively, than those in experimental animals. Therefore, the intrinsic clearance of saturable process (Vmax/Km) in humans was about one-half that in monkeys. To clarify the mechanism of the saturable clearance of NTG, the in vitro metabolic activities in rat bone marrow, spleen cells and peripheral leukocytes, which possess the G-CSF receptor, were determined. The metabolic activity of bone marrow cells was five-fold greater than that of the other cells. The in vitro metabolic and binding studies with bone marrow cells, demonstrated that the Im in NTG metabolism and Kd for NTG binding were 94 and 142 pM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Possible involvement of androgen in increased norepinephrine synthesis in blood vessels of spontaneously hypertensive rats

We investigated the effects of castration and testosterone propionate on sympathetic nervous systems in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Four-week-old male rats were castrated. For replacement of androgen, testosterone propionate (500 micrograms/rat) was administered subcutaneously 2 times a week to castrated rats after their 14th week. The systolic blood pressure of the castrated SHR (44 weeks) was significantly lower than those of intact SHR and testosterone-replaced SHR. The norepinephrine (NE) levels and the tyrosine hydroxylase (TH) activities in the abdominal aorta and mesenteric artery of castrated SHR (45-50 weeks) were significantly lower than those of intact SHR. The NE levels and the TH activities in these blood vessels of testosterone-replaced SHR recovered to the levels obtained in those of intact SHR. As well as the systolic blood pressure, the NE levels and TH activities in blood vessels of WKY were significantly lower than those of intact SHR and showed no significant difference among the three groups. These results suggest that androgen may contribute to the development of hypertension in SHR via sustained enhancement of TH activity in blood vessels leading to increased NE level.

The localization of basic fibroblast growth factor (FGF-2) in rat submandibular glands

The immunohistochemical localization of basic fibroblast growth factor (FGF-2) in the submandibular glands of the rat was investigated by use of an antiserum to FGF-2. Nerve fiber bundles with FGF-2-immunoreactivity were found in association with interlobular ducts and blood vessels; they dissociated into single immunoreactive nerve fibers perhaps to terminate in proximity to acinar cells, or to form a reticular fiber network within the tunica adventitia of blood vessels. The FGF-2-immunoreactive neurons were located in the submandibular ganglia, but not in the superior cervical ganglia; hence, at least some of these immunoreactive nerve fibers probably come from the submandibular ganglia and are of parasympathetic origin. Most of the epithelial cells of the intercalated and collecting ducts showed notable FGF-2 immunoreactivity. The characteristic distribution of FGF-2 immunoreactivity in both the neuronal and epithelial tissues of the salivary glands suggests a role of this growth factor in complex physiological processes within the salivary glands.

Three cases of extrapulmonary small cell carcinoma occurring in the prostate, stomach, and pancreas

Small cell carcinomas are fairly common neoplasms in the lung, but tumors featuring similar histological profiles may occur in extrapulmonary organs. Three cases of small cell carcinomas occurring in the prostate (case 1), stomach (case 2), and pancreas (case 3) are presented. Production of hormones was demonstrated immunohistochemically in all cases. In case 2 alpha-fetoprotein (AFP) was elevated in the serum and observed immunohistochemically in tumor cells. Production of AFP is a distinctive feature, which has not been reported in the pulmonary and extrapulmonary cases of small cell carcinoma. Amplification and/or expression of myc gene family have been suggested to be related to the prognosis of pulmonary small cell carcinoma. Amplification of myc genes was not detected in any of our cases, but c-myc protein was demonstrated immunohistochemically in tumor cells of case 1.

A molecular dynamics study of branched alpha-cyclodextrin

A branched alpha-cyclodextrin is a derivative of an alpha-cyclodextrin with a branch consisting of an extra glucose unit. Its water solubility is considerably higher than that of the unbranched one. We have studied the high solubility of the molecule in aqueous solution by molecular dynamics simulations. Trajectories of the molecule at 293 K were calculated using GROMOS programs in three different environments, i.e., in vacuo, in the crystalline state, and in aqueous solution. A simulation in vacuo was carried out to explore stable conformations of the molecule in the isolated system. The quality of the simulations were examined by comparing the X-ray and the simulated crystal structures. The results of the simulations show three remarkable structural features of the molecule: self-inclusion with its branched portion, twist-boat conformation of a glucose ring, and wobbling of its macrocycle. Among these, the last feature is closely related to the water solubility of the molecule. The solubility of cyclodextrin appears to be mainly governed by its intramolecular interglucose hydrogen bonds, which inhibit hydration by solvent water molecules. The results of our simulations indicate that the capability to form hydrogen bonds in branched alpha-cyclodextrin decreased as the macrocycle of the molecule lost its regular circular shape. Such wobbling of the macrocycle was observed on a relatively short time scale (several picoseconds). An extra glucose unit introduced to alpha-cyclodextrin may cause the improved water solubility of the molecule through the greater wobbling motion of its macrocycle.