The influence of molar furcation involvement and mobility on future clinical periodontal attachment loss

The purpose of this study was to determine the influence of furcation involvement (FI) and mobility (MO) on change in probing periodontal attachment level (AL) on molar teeth. Twenty-four patients were selected from The University of Michigan longitudinal periodontal clinical trial. The patients who met the entry criteria received a baseline examination and were treated by periodontal scaling and root planing followed by different periodontal surgical approaches in a split-mouth design. Patients were placed on a 3-month interval for maintenance prophylaxis and had yearly periodontal scorings for a period of 8 years. The scorings included determination of AL, FI, MO, and tooth loss (TL). Data for molar teeth from three different time periods (at entry (A) and at 1 (B) and 8 (C) years) were analyzed. The results demonstrated that teeth with FI were 2.54 times more likely to be lost when compared to teeth without FI during the maintenance period. By using paired t test approach to the probing attachment level data, molars with FI had significantly more loss between times B and C but not between A and B or A and C. Teeth with increased MO demonstrated significantly more AL between times A and C and B and C. When the interaction between MO and FI was analyzed, teeth with both FI and MO had significantly more attachment loss during the maintenance period (B to C). No statistically significant difference was found among the three different therapeutic approaches (pocket elimination, curettage, and modified Widman flap) during any of the time periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of root conditioning on periodontal wound healing with and without guided tissue regeneration: a pilot study. 1. Histologic evaluation

Closed fenestration wounds in four mongrel dogs were used to study the source of fibroblast proliferation and extracellular matrix production during healing; the arrangement and attachment of newly formed collagenous fibers; and the cementogenesis and osteogenesis at healing sites. Fenestration wounds were made through the alveolar bone, periodontal ligament, cementum, and dentin, and citric acid, tetracycline, or sterile water was applied to the dentinal walls for 3 minutes. Nonresorbable membranes were randomly placed over half of the defects. Animals were killed at 1, 3, 7, or 21 days and routine histologic examinations with hematoxylin and eosin staining followed. Results of this pilot study suggest that the periodontal ligament and/or alveolar bone are the main source of fibroblast proliferation and migration as well as extracellular matrix formation at the initial stages of healing, and that at 21 days, citric acid stimulated more cementogenesis than tetracycline or sterile water. Also, while the tetracycline influenced the maximal deposition of alveolar bone, no differences in healing were found between the citric acid, tetracycline, and sterile water with and without the use of membrane barriers.

Evaluation of ferric oxalate as an agent for use during surgery to prevent post-operative root hypersensitivity

The aim of this study was to evaluate the effectiveness of a 6% ferric oxalate solution applied during periodontal surgery to prevent post-operative tooth hypersensitivity. Twenty-five adult patients with similar bilateral periodontal defects participated in this study. Data were collected at baseline (1 week prior to surgery) and 1, 2, 4, and 6 weeks following surgery. Sensitivity level was determined using the visual analog scale (VAS) with the following stimuli: 1) mechanical stimulation with a No. 23 dental explorer; 2) water at 50 degrees C; 3) ice; and 4) electric pulp tester (EPT). Teeth were randomly assigned to either test (6% ferric oxalate in 0.9% saline) or control (0.9% saline) groups. Solutions were applied to the exposed root surfaces for 1 minute during surgery. Data were analyzed by repeated measures ANOVA, paired t-test, and Pearson's correlation test. Results from this study demonstrated statistically significant reduction in the responses to thermal stimuli, especially cold, between groups treated with ferric oxalate as compared to those treated with saline. For the cold test the difference increased with time from baseline to 6 weeks. Statistically significant (P < 0.05) differences in sensitivity to heat between groups were also observed, but only at 2 and 4 weeks following surgery. There were no differences at any time period between the test and control groups when tactile or EPT techniques were used. In addition, there was no correlation between sensitivity and other clinical parameters. It was concluded from this study that 6% ferric oxalate was effective in reducing post-surgical cold sensitivity when applied during periodontal surgical procedures.

[Prethrombotic state in burn patients]

78 burned patients (53 males and 25 females) were classified into 4 groups (mild: 14 cases, moderate: 13 cases, severe: 17 cases and extra--severe: 34 cases) in accordance with criteria established by the Chinese Society for Burns. 22 parameters related to platelet, coagulant and anticoagulant factors, fibrinolysis system and hemorheology were determined in the first 24 hours, and on the third and fifth post burn days. The results were as follows: Fibrinogen antigen, von Willebrand factor antigen, plasminogen activator inhibitor activity, thromboxane B2 and hematocrit and whole blood viscosity significantly increased, while antithrombin III, protein C antigen, free protein S and 6-Keto-prostaglandin F1 alpha markedly decreased as compared with normal control in the first 24 hours postburn. In addition, fibrinogen antigen, von Willebrand factor antigen, plasminogen inhibitor activity, thromboxane B2 and whole blood viscosity were persistently elevated, while antithrombin III, protein C, free protein S and 6-Keto-prostaglandin F1 alpha declined on the third and fifth postburn days. These changes resulted in a prethrombotic state, which might be an important factor in the pathogenesis of microthrombosis in burn sites, resulting in deepening of burn wound on the third and fifth days in burn patients.

Potency of 5-hydroxytryptamine1a agonists to inhibit adenylyl cyclase activity is a function of affinity for the "low-affinity" state of [3H]8-hydroxy-N,N-dipropylaminotetralin ([3H]8-OH-DPAT) binding

In this study, the radiolabeled 5-hydroxytryptamine1A agonist, [3H]8-hydroxy-N,N-dipropylamino tetralin ([3H]8-OH-DPAT), was shown to have both a high (Kd, 0.7 +/- 0.2 nM) and a low (Kd, 17 +/- 4 nM) affinity binding component in rat hippocampal homogenate preparations in the absence of guanine nucleotides. The high-affinity binding component was markedly reduced by the elimination of Mg++ from the incubation medium and the addition of both the nonhydrolyzable guanine nucleotide guanylylimidodiphosphate (Gpp(NH)p) (100 microM) and 1.0 mM EDTA to the incubation medium. Under these latter conditions, a single binding affinity component was observed with a Kd of 11 +/- 1 nM, a value in good agreement with the value for the low-affinity component measured in the absence of Gpp(NH)p. Further, the Bmax value for the single low-affinity binding component measured in the presence of Gpp(NH)p was essentially equivalent to the total of the two Bmax values found in the absence of Gpp(NH)p. A binding assay was developed using 15 nM [3H]8-OH-DPAT to determine the affinities of serotonergic drugs for the low-affinity component of [3H]8-OH-DPAT binding and these values were compared with their affinities for the high-affinity binding component as well as their potencies in a hippocampal adenylyl cyclase assay. For agonists, the Ki value for the high-affinity binding component was always less than the low-affinity Ki value, whereas the antagonist spiperone had similar values for both the high-affinity and low-affinity binding components.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular epidemiology of a variant of coxsackievirus A24 in Taiwan: two epidemics caused by phylogenetically distinct viruses from 1985 to 1989

In order to know the phylogenetic relationship and the route of transmission of a variant of coxsackievirus A24 (CA24v), an agent that caused four sequential outbreaks of acute hemorrhagic conjunctivitis from 1985 to 1989 in Taiwan, the nucleotide sequence variations in the virus-encoded proteinase 3C region (549 nucleotides) were studied with 19 isolates. The prototype strain (EH24/70), four isolates from Japan, and two isolates from Hong Kong were used for comparison. The nucleotide sequences of the Taiwan strains from the 1985-1986 and 1988-1989 epidemics were closely related within each epidemic, while they were more distantly related between strains from two epidemics. Phylogenetic analysis by the unweighted pairwise grouping method of the arithmetic average revealed that the 19 Taiwan isolates had diverged into two groups, 1985-1986 and 1988-1989 groups. The time at which these two groups diverged was estimated to be around May 1982, more than 3 years prior to the first appearance of the CA24v epidemic in Taiwan. On each occasion, the viruses caused a 2-year epidemic and then disappeared. The Taiwan isolates from 1985 to 1986 were closely related to the Japan isolates from 1985 to 1986 and the Taiwan isolates from 1988 to 1989 were phylogenetically close to the 1989 Japan isolates, indicating that Taiwan and Japan had two common-source outbreaks. However, none of the 1988 Taiwan isolates were phylogenetically close to the 1988 Japan or Hong Kong isolates. The evidence revealed that Taiwan has had two repeated but discontinuous introductions of CA24v since its first appearance in Taiwan in 1985. None of the other CA24v strains have been detected so far.

The relationship between restoration and furcation involvement on molar teeth

The purpose of this cross-sectional study was to examine the correlation between the presence of a crown (CR) or a proximal restoration (RE) and furcation involvement (FI) on molar teeth. Data were collected from 134 periodontal maintenance patients who had restored and non-restored molars present both with and without FI. A majority of the restorations that were present in these patients had been in place for at least 5 years prior to the study. First and second molars were examined clinically using the following criteria: CR, RE, FI, mobility (MO), and probing periodontal attachment level (AL). Data were analyzed with a statistical program utilizing Pearson chi-square and the pair-difference t test. The results indicated that molars with CR or RE had a significantly (P < 0.01) higher percentage of FI but no greater mobility when compared to molars without restorations. Mean probing periodontal attachment loss was greater for restored than non-restored molars but only with marginal significance (P = 0.051). There was a greater difference in mean AL between restored versus non-restored maxillary molars than for mandibular molars. This cross-sectional study provides evidence that molars with crowns or restorations involving the proximal tooth surfaces had a higher prevalence of FI and greater AL than molars without restorations.

Intact lung cytochrome P-450 is not required for hypoxic pulmonary vasoconstriction

Lung cytochrome P-450 has been suggested to play a role in hypoxic pulmonary vasoconstriction. We reexamined this hypothesis using specific suicide substrate inhibitors of cytochrome P-450, 1-aminobenzotriazole (1-ABT), and chloramphenicol. In isolated, blood-perfused rat lungs, 1-ABT (0.5 mg/ml) and chloramphenicol (1 mg/ml) inhibited lung microsomal cytochrome P-450 (ethoxycoumarin O-deethylase) activity to 24 and 44% of control, respectively, and blunted hypoxia and angiotensin II-induced vasoconstriction. The depression of vascular contraction by 1-ABT was not due to an effect on calcium channels, since similar concentrations of 1-ABT had no inhibitory activity on electrical field-stimulated contractile response in rabbit papillary muscle strips. However, when 1-ABT was washed out of the lung after preincubation, the vascular reactivity to hypoxia and angiotensin II was restored despite persistent depression of lung cytochrome P-450 activity to 26% of control values. In isolated rat aortic and pulmonary arterial rings, addition of 1-ABT or metyrapone to the organ bath acutely reversed norepinephrine-induced contraction but preincubation with 1-ABT, metyrapone, or chloramphenicol had no effect on subsequent norepinephrine contractions. We conclude that 1-ABT inhibited lung vascular reactivity by a mechanism independent of cytochrome P-450 inhibition or calcium channel blockade and that an intact lung cytochrome P-450 system is not required for hypoxic pulmonary vasoconstriction in rat lungs.

[Multiple leiomyosarcomas of extremities]

Leiomyosarcoma is an uncommon tumor that rarely occurred in extremity. Multiple leiomyosarcomas in different extremities is even rarer. We report a 90 year-old male veteran who was found to have four leiomyosarcomas, one in right arm and the other three in right thigh. The patient sustained gunshot injuries over right thigh and right arm about 60 years ago in a war with severe wound sepsis due to open communited fracture of the femur. These tumors happened to distribute in the vicinity of the old scars. It was speculated that these multicentric tumors were due to decreased immune surveillance caused by aging and induced by the previous trauma. The literatures were reviewed and the diagnostic methods, surgical treatment and the adjuvant therapy were discussed.

Expression of olfactory receptors in Xenopus oocytes

The rat olfactory epithelium and the amino acid-sensitive catfish olfactory system have been used as models to study the molecular mechanisms of olfactory transduction. Here we report the functional expression of rat and catfish olfactory receptors in Xenopus oocytes injected with mRNA isolated from the respective tissues. Application of odor ligands to injected oocytes, monitored by two-electrode voltage clamp, activates stimulus-dependent transmembrane currents that reverse direction at about the chloride equilibrium potential. The currents show characteristic secondary oscillations that are presumed to reflect underlying Ca2+ oscillations. Similar ligand-activated membrane currents induced in oocytes after injection of other mRNAs have been shown to be due to activation of endogenous Ca(2+)-activated chloride channels. In summary, our results demonstrate the usefulness of the Xenopus oocyte expression system for cloning and characterization of olfactory receptors in both fish and mammalian species.

[A clinicopathological study of leukemic kidney]

A clinicopathological study of leukemic kidney was carried out by observing the changes of the kidney in 104 autopsied cases of leukemia. The main changes of the leukemic kidney were increase of renal weight, calcinosis of renal tubules, interstitial leukemic cell infiltration, intravascular stasis and renal bleeding. Calcinosis intravascular stasis, renal bleeding as well as hyperuricemia may lead to abnormal urinary findings. The presence and severity of interstitial infiltration have no obvious relation with the level of blood urea nitrogen, creatinine and muric acid as well as the abnormal change of the urine. However, the presence of intravascular stasis by leukemic cells are correlated with the disturbance of renal function.

Periodontal connective tissue

Connective tissues of the periodontium are composed of cells and their related extracellular matrix components. For these tissues to respond appropriately during development and regeneration as well as in health, a precise regulation of cell-cell interactions and cell-substrata interactions must occur. Thus, in order to achieve more predictable clinical results, it is critical that the mechanisms and proteins and factors guiding tissue development, maintenance, and regeneration be understood at the cellular and molecular level. This has resulted in an increased emphasis on identifying components of the periodontium and subsequently determining how these proteins and factors regulate cell behavior. This review summarizes our current knowledge of the proteins and factors considered important to development, maintenance, and regeneration of periodontal tissues.

Systemic and mesenteric O2 metabolism in endotoxic pigs: effect of graded hemorrhage

Normally, supply-dependency of oxygen uptake (VO2) is not demonstrable unless oxygen delivery (DO2) is less than a critical value (DO2crit) below which VO2 is linearly dependent upon DO2. Because recent evidence suggests that VO2 is pathologically supply-dependent in endotoxic or septic animals and humans, we sought to determine whether 1) pathological systemic and/or mesenteric oxygen extraction (O2EXT) defects occur in a porcine model of endotoxicosis and 2) arterial lactate and ileal intramucosal pH (pHI) serve as useful markers of supply-dependency of VO2 in endotoxic animals. Normal (group I, n = 11) and endotoxic (group II, n = 8) anesthetized pigs were subjected to graded hemorrhage. Endotoxicosis was induced by infusing Escherichia coli lipopolysaccharide (150 micrograms/kg bolus at t = 0 min and 20 micrograms/kg-hr at t = 60 min). From t = 0-60 min, pigs in group II were resuscitated with hetastarch and blood (12 ml/kg each). Hemorrhage was initiated at t = 0 min or t = 70 min in groups I and II, respectively. DO2crit was determined by a modified "dual-line" regression method. Systemic DO2crit was 12.9 +/- 0.9 ml/kg-min in group I and 16.9 +/- 1.3 ml/kg-min in group II (P less than .05). Systemic O2EXT at DO2crit was similar in both groups. Arterial lactate concentration at DO2crit was significantly higher in endotoxic pigs (group I, 2.64 +/- 0.29 mM; vs. group II, 3.88 +/- 0.45 mM; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Experience with bromocriptine for the treatment of female infertility due to hyperprolactinemia

From July 1981 to September 1988, 106 infertile patients with hyperprolactinemia treated with bromocriptine were reviewed retrospectively with special attention to the dosage of bromocriptine and the evaluation of infertility before treatment. 84 patients (79.2%) became pregnant. The 106 patients were divided into 3 groups according to the following doses: 7.5, 5.0, and less than 5.0 mg/day. The pregnancy rate was 90.7%, 84.6%, and 66.7% respectively with the highest at 7.5 mg/day, which was significantly higher than that at less than 5.0 mg/day (P less than 0.02). The average duration from treatment to pregnancy was 3.6, 3.4 and 7.4 months respectively. The longest duration in the less than 5 mg/day group was twice that in the other two groups. 85% of the pregnancies occurred within 6 months of treatment. Pretreatment of organic lesions and additional therapy for induction of ovulation were given to 29.8% of the pregnancies. The causes of infertility other than hyperprolactinemia were evaluated systemically before the use of bromocriptine. The optimal dose was 5-7.5 mg/day. Macroprolactinomas can be treated with bromocriptine, but should be followed up closely for the development of symptoms of intracranial pressure during pregnancy.

Subtypes of brain somatostatin receptors couple to multiple cellular effector systems

To investigate whether somatostatin (SRIF) receptor subpopulations mediate different physiological actions of SRIF, we tested the effects of SRIF and the SRIF agonists MK 678 and CGP 23996 on different biological responses in rat neocortical neurons in culture. Neocortical cells in culture express SRIF receptors that can be labeled with 125I-MK 678 and 125I-CGP 23996. Pharmacological analysis of the binding sites indicates that the radioligands label SRIF receptor subtypes with distinct pharmacological characteristics. These receptor subpopulations are similar to those expressed in adult rat brain. SRIF, MK 678, and CGP 23996 are able to inhibit forskolin-stimulated adenylate cyclase activity in rat neocortical membranes by 25-30%. Furthermore, they inhibit a high voltage-activated Ca2+ current in rat neocortical neurons in culture by 25-35%. Both SRIF and MK 678 potentiate a delayed rectifier K+ current in rat neocortical neurons in culture by 25-30%. In contrast, high concentrations of CGP 23996 do not alter the K+ current. In cells that do not respond to CGP 23996, MK 678 increases the delayed rectifier K+ current. The findings of these studies indicate that rat neocortical neurons in culture express functionally distinct SRIF receptor subtypes that can be differentially activated by SRIF agonists.

Maintenance of superior mesenteric arterial perfusion prevents increased intestinal mucosal permeability in endotoxic pigs

Lipopolysaccharide increases intestinal mucosal permeability to hydrophilic compounds such as chromium 51-labeled edetate (51Cr-EDTA). We sought to determine whether this phenomenon is partly mediated by lipopolysaccharide-induced mesenteric hypoperfusion. We assessed permeability in an isolated segment of ileum by measuring plasma-to-lumen clearances (C) for two probes, 51Cr-EDTA and urea, and expressing the results as a ratio (CEDTA/CUREA). In control pigs (n = 6) resuscitated with Ringer's lactate (RL), mucosal permeability was unchanged during the 210-minute period of observation. In pigs (n = 7) infused with lipopolysaccharide (50 micrograms/kg) and similarly resuscitated with RL, mesenteric perfusion (Qsma) decreased significantly and permeability increased progressively and significantly. When endotoxic pigs (n = 6) were resuscitated with a regimen (RL plus hetastarch plus dobutamine) that preserved normal Qsma, lipopolysaccharide-induced mucosal hyperpermeability was prevented. Resuscitation of endotoxic pigs (n = 6) with RL plus hetastarch provided intermediate protection against both mesenteric hypoperfusion and increased permeability. These data suggest that diminished Qsma contributes to impaired ileal mucosal barrier function in experimental endotoxicosis.

Delayed treatment with an LTD4/E4 antagonist limits pulmonary edema in endotoxic pigs

We used a selective leukotriene (LT) D4/E4 receptor antagonist (LY 203647) to investigate the role of cysteinyl LTs as mediators of several important pathophysiological events in a porcine model of endotoxic shock. Pentobarbital-anesthetized pigs (11.8-17.5 kg) were mechanically ventilated with 100% O2. Pigs in groups I (n = 10), IIA (n = 10), and IIB (n = 5) were infused with Escherichia coli lipopolysaccharide (LPS; 250 micrograms/kg) from time (t) = 0-20 min. Pigs in group III (n = 3) were normal controls. All pigs were resuscitated from t = 0-240 min with Ringer lactate (0.8 ml.kg-1.min-1). Pigs in group I received no further treatment. At t = 30 min, groups IIA and IIB were injected with LY 203647 (30 mg/kg) and were started on an infusion of the compound at 10 (group IIA) or 30 mg.kg-1.h-1 (group IIB). Delayed treatment with LY 203647 significantly (P less than 0.05) and persistently ameliorated LPS-induced pulmonary hypertension. The compound also abrogated LPS-induced pulmonary edema, as assessed by gravimetrically determined lung extravascular wet-to-dry weight ratios. Despite its beneficial effect on pulmonary edema, delayed treatment with LY 203647 did not improve arterial oxygenation. Delayed treatment with LY 203647 transiently improved mesenteric perfusion. These data suggest that cysteinyl LTs are important mediators in porcine endotoxicosis.

Insulin-induced mitogenesis associated with transformation by the SV40 large T antigen

Simian virus 40 (SV40) large T antigen-transformed cells typically show a markedly reduced serum requirement for growth and the inability to growth arrest and differentiate. An SV40 large T antigen-transformed 3T3 T cell line, CSV3-1, that can growth arrest and differentiate into adipocytes with high efficiency has, however, recently been described (Scott et al: Proc. Natl. Acad. Sci. U.S.A. 86:1652-1656, 1989; Estervig et al: J. Virol. 63:2718-2725, 1989; J. Cell. Physiol. 142:552-558, 1990). The results of the current studies using these cells show that whereas quiescent 3T3 T cells show no mitogenic response to insulin, quiescent CSV3-1 cells show a highly significant insulin-induced mitogenic responsiveness in the absence of other added growth factors. Maximum mitogenesis was observed at an insulin concentration of 1 microgram/ml, which induced 40-70% of the cells to undergo DNA synthesis within 48 hours. The half maximum response was achieved with 1-10 ng/ml of insulin. Insulin's mitogenic effect on CSV3-1 cells was evident under several different culture conditions that induce quiescence and was not mediated by any detectable autocrine growth factors that might make CSV3-1 cells competent to respond to insulin. In CSV3-1 cells insulin appears to act on its own receptor rather than on the IGF-1 receptor, because at comparable dosages IGF-1 is 10- to 100-fold less effective than insulin. Insulin also is shown to be a mitogen for another SV40-transformed cell line, CSV3-35, which can be growth arrested; in contrast insulin has no mitogenic effect on two control cell lines that are stably transfected with pSV2neo, a plasmid containing SV40 early promoter/enhancer but lacking large T antigen gene: These results suggest a significant relationship between SV40 T antigen-associated transformation and the expression of mitogenic responsiveness to insulin.

Leukotriene C4 induces mesenteric hypoperfusion and intestinal intramural acidosis in pigs

We examined the effect of intravenous infusion of graded doses of authentic leukotriene (LT) C4 on several physiological variables in pentobarbital-anesthetized immature swine. Mesenteric blood flow (Qsma) was measured using an ultrasonic flow probe and ileal intramucosal hydrogen ion concentration ([H+]I) was estimated tonometrically. Three groups were studied. Pigs in Group I (n = 6) were infused beginning at t = 0 min with increasing doses (0.03-1.0 microgram/kg-min) of LTC4, each dose being administered for 10 min. Pigs in Group II (n = 6) were infused with LTC4 as above, but were pre- and post-treated with a specific sulfidopeptide LT receptor antagonist, LY203647 (30 mg/kg bolus and then 10 mg/kg-hr) beginning at t = -20 min. Pigs in Group III (n = 4) received only normal saline (5 ml/kg-h). Infusing LTC4 significantly decreased Qsma and mesenteric oxygen uptake and significantly increased ileal [H+]I. These changes were prevented by LY203647. These data support the idea that sulfido-peptide LT are capable of causing mesenteric ischemia and that this phenomenon can be blocked by LY203647.

Increased intestinal permeability in endotoxic pigs. Mesenteric hypoperfusion as an etiologic factor

Infusing pigs with lipopolysaccharide (LPS) decreases superior mesenteric artery blood flow (Qsma), suggesting that mesenteric hypoperfusion may be responsible for LPS-induced alterations in gut mucosal permeability. To test this hypothesis, we studied four groups of anesthetized swine. Group 1 animals (N = 6) were infused with LPS (250 micrograms/kg over 1 hour beginning at 60 minutes) and continuously resuscitated with Ringer's lactate (48 mL/kg per hour). In group 2 (N = 5), Qsma was decreased by 50% by means of a mechanical occluder to mimic the LPS-induced alterations in Qsma observed in group I. Group 3 (N = 5) was included to document our ability to detect ischemia/reperfusion-induced alterations in mucosal permeability; in these pigs, Qsma was decreased in steps to zero flow (at 150 to 210 minutes) and then perfusion was restored (at 210 to 270 minutes). Pigs in group 4 (N = 6) served as normal controls; these animals were resuscitated with Ringer's lactate at the same rate as in group 1 but were not infused with LPS. To assess mucosal permeability, we measured plasma-to-lumen clearances for two markers, chromium 51-labeled edetic acid monohydrate (EDTA) and urea. Loading and maintenance infusions of the markers were given intravenously, and a 20-cm isolated segment of small intestine was continuously perfused at 2 mL/min with Ringer's lactate at 37 degrees C. Results were expressed as the ratio of the clearances for the two probes (CEDTA/CUREA). In group 3, CEDTA/CUREA was 999% +/- 355% of baseline at 270 minutes. In group 1, CEDTA/CUREA was 572% +/- 235% of baseline at 270 minutes. In groups 2 and 4, however, CEDTA/CUREA did not change significantly from the baseline value over the duration of the study. These data suggest that increased mucosal permeability after LPS is due to factors other than (or in addition to) mesenteric hypoperfusion.

Beneficial effects of LY203647, a novel leukotriene C4/D4 antagonist, on pulmonary function and mesenteric perfusion in a porcine model of endotoxic shock and ARDS

The sulfidopeptide leukotrienes (LT) have been implicated as important pathophysiological mediators in septic shock. To further define the role of these compounds, we utilized a porcine endotoxicosis model to study the effects of pre- and concurrent treatment with LY203647, a novel LT receptor antagonist. Pentobarbital-anesthetized pigs (13-20 kg) were mechanically ventilated with 100% O2. Superior mesenteric arterial flow (Qsma) was measured using an ultrasonic flow probe. Ileal intramucosal hydrogen ion concentration, [H+]1, was estimated tonometrically. Pigs in groups I and II were infused with endotoxin (250 micrograms/kg) and resuscitated with saline (1.2 ml/kg min). Group I (n = 8) were controls; Group II (n = 8) were pretreated with LY203647 (30 mg/kg bolus, then 10 mg/kg h). Treatment with LY203647 persistently and significantly (P less than .05) improved post-LPS pO2 and transiently improved Qsma. Treatment with LY203647 did not affect [H+]1. Lung extravascular wet-to-dry weight ratios were 7.13 +/- .33 and 5.43 +/- .09 in groups I and II, respectively (P less than .001). These data suggest that sulfidopeptide LT are important mediators of key pathophysiologic events in this porcine model of endotoxic shock and the adult respiratory distress syndrome (ARDS).

Validation of tonometric measurement of gut intramural pH during endotoxemia and mesenteric occlusion in pigs

Tonometry is a minimally invasive method for estimating gastrointestinal intramural pH (pHi). Tissue pH is calculated by using the Henderson-Hasselbalch equation and measurements of arterial [HCO-3] and CO2 tension (PCO3) of saline contained in a Silastic balloon within the lumen of the gut. The validity of the method rests on two key assumptions: 1) PCO2 in saline in the tonometer balloon is similar to tissue PCO2 and 2) tissue and arterial [HCO-3] are similar. To validate this method, ileal pHi measured directly with a microelectrode was compared with pHi estimated tonometrically in four groups of anesthetized pigs. Group I (n = 4) were controls. In group II (n = 4), intestinal tissue acidosis was induced by total occlusion of the superior mesenteric artery (SMA). In group III (n = 5), acidosis was induced by partial occlusion of the SMA. In group IV (n = 4), tissue acidosis was induced by endotoxemia. Agreement was excellent between direct and tonometric measurements in groups I and IV and less good in groups II and III. Weighted mean correlation coefficients (rw) for the two measurement methods were 0.743 and 0.9447 in groups II and IV, respectively. Correlation coefficients for the individual animals in group III were more variable than the other groups and ranged from 0.547 to 0.990. The tonometric method for measuring GI pHi is invalid under conditions of zero flow and leads to error under conditions of low flow. However, the method is reliable in the setting of tissue acidosis induced by endotoxemia.

Electrophysiological effects of somatostatin-14 and somatostatin-28 on mammalian central nervous system neurons

Somatostatin (SOM) exists in at least two active forms in the central nervous system (CNS): SOM-14 and SOM-28. These peptides have multiple actions on neurons in the CNS and these actions appear to be mediated by different receptors. Thus, SOM-14 can enhance voltage-dependent K currents, whereas SOM-28 inhibits these same currents, sometimes even in the same neurons. These effects are not mediated via cAMP, but do seem mediated by GTP-binding proteins. On the other hand, both forms of SOM inhibit a voltage-dependent Ca current, again via a GTP-binding protein. SOM can also interact with the GABA(A) receptor to modulate responses to this inhibitory transmitter. The physiological effects of SOM in an integrated circuit within the CNS will depend on the form of SOM released, the kinds and numbers of receptors present on the postsynaptic neurons, and the presence of other neurotransmitters.

Lack of cross-desensitization of somatostatin-14 and somatostatin-28 receptors coupled to potassium channels in rat neocortical neurons

The effects of somatostatin-14 (SOM-14) and somatostatin-28 (SOM-28) on the delayed rectifier K+ current (IK) in rat neocortical neurons in culture were measured by using whole-cell patch clamp techniques. SOM-14 stimulated IK in a reversible manner. Continuous application of SOM-14 to the neocortical neurons led to a gradual desensitization of the SOM-14 response. Many cells became completely densensitized to SOM-14. SOM-28 also modulated IK in neocortical cells. However, SOM-28 reduced IK. This response was also reversible. Continuous application of SOM-28 to neocortical neurons led to a desensitization of the SOM-28 inhibition of IK. Many of the neurons that responded to SOM-28 became completely refractory to the peptide following prolonged SOM-28 pretreatment. While most neocortical neurons responded either to SOM-14 or to SOM-28, a population of neurons responded to both peptides. Chronic application of SOM-14 to these neurons completely desensitized the SOM-14 stimulation of IK but did not affect SOM-28 inhibition of this potassium current. Similarly, complete desensitization of SOM-28 responses in these cells was not associated with a modification of SOM-14 stimulation of IK. The lack of cross-desensitization between SOM-14 and SOM-28 induced responses suggests that these peptides act through different receptors to regulate IK.

The effect of low-dose estrogen and progestogen on menopausal symptoms and urinary excretion of calcium

The effects of low-dose estrogen and progestogen on menopausal symptoms were studied with Kuppermen score and urinary excretion of calcium as fasting morning urine Ca/Cr ratio in 69 perimenopausal women. The subjects were divided into 3 groups: amenorrhea less than 1 year (14 women); post menopause 1-3 years (19); and post menopause more than 3 years (36). Fasting urine Ca/Cr ratio in the post menopause 1-3 years group was 0.19 +/- 0.01, significantly higher than that (0.14-0.01) in the amenorrhea less than 1 year group and (0.11 +/- 0.006) the post menopause more than 3 years group. 18 women had 4 patterns of low-dose oral estrogen and progestogen: MPA 2 mg QOD, EE 5 micrograms QD, EE 5 micrograms QOD, and EE 5 micrograms and MPA 2 mg QOD. Each pattern was used in turn for 3 weeks, and discontinued for 2 weeks, then the next pattern started and so on. EE 5 micrograms and MPA 2 mg QOD alternately gave the best results both in improving symptoms and lowering urine Ca/Cr ratio. Seven women given intermittent large dose, namely, EE 50 micrograms every 10 days or premarin 2.5 mg every 7 days had symptoms relieved but inconsistent decrease of urine Ca/Cr ratio.

[Clinical research of hypercoagulation in patients with diabetes mellitus, glomerular diseases and pregnancy induced hypertension]

The hypercoagulable state in patients with diabetes mellitus, glomerular diseases and pregnancy induced hypertension was studied by using new methods. The research items included platelet function, coagulation, anti-coagulation system, fibrinolysis and TEG examination. The results showed that there was a hypercoagulable state in patients with diabetes mellitus, pregnancy induced hypertension and glomerular diseases, especially in those with uremia and nephrotic syndrome.

Crevicular fluid iron changes in treated and untreated periodontally diseased sites

Previous investigations have shown that crevicular fluid iron concentration (CFIC) is higher in periodontally diseased sites. The present study was conducted to determine whether periodontal treatment changes the CFIC to levels found in healthy sites in the same persons. To test the significance of iron content in gingival fluid as an indicator of periodontal disease severity or activity, CFIC was determined for healthy sites and diseased sites treated with scaling and root planing alone or in conjunction with surgery both before and after treatment. CFIC was increased in diseased sites, but the iron concentration in crevicular fluid was not a good indicator of changes in disease severity resulting from periodontal treatment. Treatments produced an increase in the CFIC that may be more related to the status of the microcirculation than to the disease process itself.

Somatostatin-14 and somatostatin-28 inhibit calcium currents in rat neocortical neurons

The prosomatostatin-derived peptides, somatostatin-14 and somatostatin-28, are believed to function as neurotransmitters or neuromodulators in the cerebral cortex. To investigate the molecular mechanisms by which these peptides induce their physiological effects in the cerebral cortex, we have examined the effects of somatostatin-14 and somatostatin-28 on voltage-dependent Ca2+ currents in rat neocortical neurons in culture. Ca2+ currents were recorded using whole-cell patch-clamp techniques under conditions in which K+ and Na+ currents were blocked. Ca2+ currents were induced by depolarization from the holding potential of -80 mV. Somatostatin-14 (100 nM) and somatostatin-28 (100 nM) did not significantly affect low-voltage activated Ca2+ currents, but blocked high-voltage activated Ca2+ currents and slowed the activation of this current. The effects of both peptides were concentration-dependent and reversible. Furthermore, the effects of somatostatin-14 and somatostatin-28 on the high-voltage activated Ca2+ currents were not additive, suggesting that both peptides regulate this ionic current through similar cellular mechanisms. When patch pipettes used to record the Ca2+ currents contained 100 microM cAMP and 0.5 mM isobutylmethylxanthine, a phosphodiesterase inhibitor, somatostatin-14 and somatostatin-28 still inhibited Ca2+ currents, indicating that the effects of these peptides on the Ca2+ currents were cAMP-independent. Inclusion of the non-hydrolysable guanine triphosphate analogue, guanine triphos-somatostatin-14 or somatostatin-28, suggesting the involvement of guanine nucleotide binding proteins in the actions of the peptides on the Ca2+ currents.(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic and mesenteric O2 metabolism in endotoxic pigs: effect of ibuprofen and meclofenamate

The effect of two chemically dissimilar cyclooxygenase inhibitors was studied in pentobarbital-anesthetized endotoxic pigs. Animals in groups II-IV were infused with Escherichia coli lipopolysaccharide (LPS, 150 micrograms/kg) and resuscitated with normal saline (1.2 ml.kg-1.min-1). Animals in group I (n = 4) were resuscitated as above but were not infused with LPS. Animals in group II (n = 7) served as endotoxic controls. Pigs in groups III (n = 6) and IV (n = 5) were pre- and posttreated with ibuprofen (10 mg/kg bolus then 10 mg.kg-1.h-1 and meclofenamate (5 mg/kg then 5 mg.kg-1.h-1, respectively. Ileal intramucosal hydrogen ion concentration [( H+]) was estimated tonometrically. In group I, cardiac index (CI), mean arterial pressure (MAP), superior mesenteric arterial perfusion (QSMA), and mesenteric O2 delivery (DO2) increased significantly, but other variables were unchanged. After infusion of LPS in group II, MAP and systemic vascular resistance index were markedly diminished but CI was well preserved. In this group, QSMA, systemic DO2, and mesenteric DO2 decreased, whereas systemic O2 uptake (VO2) and gut [H+] increased; mesenteric VO2 was unchanged. Compared with pigs in group II, pigs treated with ibuprofen or meclofenamate manifested improved systemic and mesenteric DO2. In groups III and IV, QSMA remained normal, increased systemic VO2 was not observed, and gut intramucosal acidosis was ameliorated. Increased intramucosal [H+] in group II suggests that QSMA was inadequate. The salutary effects of ibuprofen and meclofenamate suggest that inadequate mesenteric perfusion was mediated, at least in part, by cyclooxygenase-derived metabolites or arachidonic acid.

[Preliminary investigation of neurasthenic syndrome induced by occupational hazards]

In this article, an investigation on prevalence of neurasthenic syndrome applying the Clinical Operational Diagnostic Criteria formulated by the Editorial Committee of Chinese Journal of Neurology and Psychiatry (1985), in 166 workers exposed to three kinds of occupational hazard including industrial noise, high frequency magnetic field, and benzene compounds, and matching with 166 workers selected from other workshop in same factory as the controls, was carried out in a diesel engine factory at suburban area, Changzhou City. It was found that the prevalence of neurasthenic syndrome in former group were 26.6%, 35.4%, and 33.3%, respectively. In corresponding control group were 1.06%, 4.2%, and zero percent, respectively. The results revealed no statistic difference among three subgroups of the former, but there were significantly higher then that of the control group with P value in 0.01 level. Base on above data, the authors considered that along the development of industrial modernization, the occupational hazardous factors will be seriously affected the workers health from various aspect. Therefore, these occupational health problems, should be concerned as a top priority in industrial hygiene. We also stressed that the personal protective measure must be set up and put into practice immediately, as it may be play an important role to decrease the prevalence of neurasthenic syndrome. Finally, the possible mechanism of occupational hazards damaging the function of C.N.S. and some related questions were briefly discussed.

Vasopressin-induced pulmonary vasodilation in rats

Experiments were performed to determine the pulmonary vascular responses to exogenous or endogenous arginine vasopressin (AVP) in rats. Both in vitro and in vivo approaches were used to examine the direct pulmonary vasoactive properties of AVP and how those properties affect pulmonary hemodynamics in the intact animal. In conscious, unrestrained rats, constant infusion of AVP (4.0 mU.kg-1.min-1 iv) resulted in a fall in mean pulmonary artery pressure (PAP), although systemic pressure was increased. Coincident with the fall in PAP were similar reductions in cardiac output and heart rate. Similarly, bolus administration of AVP reduced PAP, and this effect was augmented during hypoxia. Another series of experiments examined the effect of endogenous AVP released by arterial hypoxemia on pulmonary hemodynamics in conscious rats. Administration of a specific V1-vasopressinergic antagonist had no effect on the PAP response to hypoxia; however, systemic resistance tended to fall following V1-antagonism. To determine the vasoactive properties of AVP independent of these changes in blood flow, a series of experiments were performed on isolated, perfused rat lungs. Injection of 25, 200, or 2,000 mU of AVP into the circulation of the isolated lung was without effect under normoxic conditions. In contrast, 25 mU AVP elicited reproducible pulmonary vasodilation when injected during ongoing hypoxic pulmonary vasoconstriction. This vasodilatory response was unaffected by meclofenamate or by the platelet-activating factor receptor antagonist SRI 63-441, but was blocked by a specific V1-vasopressinergic antagonist. We conclude that although AVP exerts profound systemic vasoconstriction, the pulmonary circulation appears relatively unaffected by exogenous or endogenous AVP in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Norepinephrine induces lung vascular prostacyclin synthesis via alpha 1-adrenergic receptors

Sympathetic nerve stimulation can cause pulmonary vasoconstriction related to norepinephrine (NE) release. Because of recent reports that NE caused prostacyclin (PGI2) release from systemic arteries, we wondered whether NE caused pulmonary vascular PGI2 release and whether a feedback mechanism existed whereby PGI2 modulated NE-induced vasoconstriction. NE-induced PGI2 synthesis in rat main pulmonary artery rings was larger than that induced by KCl, passive stretch, or a thromboxane analogue, was alpha-adrenergic receptor dependent, and was enhanced by endothelium removal. The NE-induced PGI2 synthesis was not tightly coupled to the magnitude of the pulmonary artery ring contractile response, and inhibition of NE-induced PGI2 production by cyclooxygenase blockade in either the pulmonary artery ring preparation or in isolated rat lungs perfused with a physiological solution did not augment the magnitude of the contractile response. We concluded that NE is a potent stimulus for PGI2 synthesis in the rat main pulmonary artery ring and in the rat lung, yet PGI2 is not important as a modulator of NE-induced vasoconstriction in the rat lung.

The three-dimensional anatomy of the proximal femur in Perthes' disease

A new method of recording the three-dimensional anatomy of the proximal femur from a single anteroposterior radiograph is described. This technique shows that in Perthes' disease the femoral head and neck are in significant anteversion and true varus. This anatomical configuration may be important in the pathogenesis and treatment of this disorder.

Neurological and electroneuromyographic assessment of the adverse effects of acrylamide on occupationally exposed workers

Seventy-one acrylamide workers and fifty-one unexposed referents were studied. Weak legs and numb hands and feet, preceded by skin peeling from the hands, were the early symptoms of the acrylamide workers; their early signs were impairment of vibration sensation in their toes and loss of ankle reflexes. Three cases had cerebellar involvement followed by polyneuropathy due to heavy exposure. Electroneuromyographic changes, including a decrease in the sensory action potential amplitude, neurogenic abnormalities in electromyography, and prolongation of the ankle tendon reflex latency, are of greater importance in the early detection of acrylamide neurotoxicity since they can precede the neuropathic symptoms and signs. The diagnostic criteria for occupational acrylamide intoxication of this study revealed three severe poisonings, six moderate poisonings, and 43 mild poisonings. The total prevalence of acrylamide poisoning was 73.2%. The prevention of dermal exposure to acrylamide should be emphasized.

Biochemical properties of brain somatostatin receptors

The physical properties of brain and pituitary somatostatin receptors were characterized using photocrosslinking techniques. Somatostatin receptors in rat corpus striatum and anterior pituitary membranes were covalently bound to the non-reducible somatostatin analog, [125I]CGP 23996, using the crosslinking agent n-hydroxysuccinimidyl-4-azidobenzoate and ultraviolet light. In striatal membranes, a protein of 60,000 mol. wt was labeled by [125I]CGP 23996. The binding was potently inhibited by somatostatin analogs but not by other biologically active peptides. The labeling of the 60,000 mol. wt protein by [125I]CGP 23996 was diminished by guanine triphosphate gamma thiol, which is consistent with the labeling of a somatostatin receptor coupled to guanine triphosphate binding proteins. The migration of the [125I]CGP 23996 labeled 60,000 mol. wt protein in native sodium dodecyl sulfate-gels was not affected by the reducing agent dithiothreitol, indicating that there is a general lack of disulfide bridges in the striatal somatostatin receptor. The striatal somatostatin receptor was solubilized with the detergent 3-[(3-cholamidopropyl)-dimethylaminoio]-1-propanesulfonate and specifically bound to the lectin wheat germ agglutinin, suggesting that the striatal somatostatin receptor is a glycoprotein. [125I]CGP 23996 also labeled a 60,000 mol. wt protein in anterior pituitary membranes. The characteristics of [125I]CGP 23996 binding to anterior pituitary membranes were consistent with the labeling of a somatostatin receptor. Interestingly, a comparison of the [125I]CGP 23996 labeled material from striatal and anterior pituitary membranes by two-dimensional polyacrylamide gel electrophoresis revealed the presence of several striatal somatostatin receptors of varying charge (pI values between 6 and 6.5) but only a single pituitary receptor. These findings indicate that physical differences may exist between subtypes of somatostatin receptors.

Somatostatin inhibits cAMP-dependent and cAMP-independent calcium influx in the clonal pituitary tumor cell line AtT-20 through the same receptor population

The characteristics of somatostatin (SRIF) inhibition of calcium influx stimulated by corticotropin releasing factor (CRF), an activator of adenylate cyclase, and K+, a membrane depolarizing agent, in AtT-20 cells were assessed. Changes in cytosolic calcium levels were measured using the fluorescence probe Quin 2. Both CRF and K+ raise cytosolic calcium levels by stimulating calcium influx. SRIF induced an immediate inhibition of CRF and K+-stimulated calcium influx. This effect was concentration-dependent with IC50 values for SRIF's blockade of CRF and K+ stimulation of 64 +/- 13 pM and 100 +/- 15 pM, respectively. The SRIF analogs, SRIF 28, Trp8-SRIF and Tyr11-SRIF had the same rank order of potency to block CRF and K+-induced calcium influx. The inhibitory effects of SRIF on AtT-20 cells were abolished by pertussis toxin pretreatment. SRIF inhibition of both CRF and K+-induced calcium influx desensitized. The desensitization was rapid (T1/2 approximately 2.5 min), dependent on the concentration of SRIF and not due to the degradation of the peptide. The ability of SRIF to block CRF (cyclic AMP-dependent) and K+ (cyclic AMP-independent)-stimulated calcium influx into AtT-20 cells cannot be separated.

A spin labeling study of calf thymus DNA

2,2,6,6-Tetramethyl-4-(bis-ethyleneimino) triazinamino-piperidine-1-oxyl was used as the spin label. In ESR spectra of the product obtained (SL-DNA), the strongly immobilized peak greatly prevailed over the weakly immobilized component and a significant difference existed between their microwave saturation characteristics. The spin labeling reaction was investigated in some details. With the aid of heat denaturation (100 degrees C, 15 min) of SL-DNA in conjunction with acid degradation (pH 1.5, 37 degrees C, 23 h), the quantity of labels bound to DNA was determined. Namely, the number of labels bound to 1000 nucleotides was found to be 4.0-12.6. The structural transition temperature of SL-DNA attained from variable temperature measurements was about 63 degrees C and a rise in this temperature was observed with increasing salt concentration.