An αIIb ß3 antagonist prevents thrombosis without causing Fc receptor γ-chain IIa-mediated thrombocytopenia.

Essentials FcγRIIa-mediated thrombocytopenia is associated with drug-dependent antibodies (DDAbs). We investigated the correlation between αIIb ß3 binding epitopes and induction of DDAbs. An FcγRIIa-transgenic mouse model was used to evaluate thrombocytopenia among anti-thrombotics. An antithrombotic with binding motif toward αIIb ß-propeller domain has less bleeding tendency. SUMMARY: Background Thrombocytopenia, a common side effect of Arg-Gly-Asp-mimetic antiplatelet drugs, is associated with drug-dependent antibodies (DDAbs) that recognize conformation-altered integrin αIIb ß3 . Objective To explore the correlation between αIIb ß3 binding epitopes and induction of DDAb binding to conformation-altered αIIb ß3 , we examined whether two purified disintegrins, TMV-2 and TMV-7, with distinct binding motifs have different effects on induction of αIIb ß3 conformational change and platelet aggregation in the presence of AP2, an IgG1 inhibitory mAb raised against αIIb ß3 . Methods We investigated the possible mechanisms of intrinsic platelet activation of TMV-2 and TMV-7 in the presence of AP2 by examining the signal cascade, tail bleeding time and immune thrombocytopenia in Fc receptor γ-chain IIa (FcγRIIa) transgenic mice. Results TMV-7 has a binding motif that recognizes the αIIb ß-propeller domain of αIIb ß3 , unlike that of TMV-2. TMV-7 neither primed the platelets to bind ligand, nor caused a conformational change of αIIb ß3 as identified with the ligand-induced binding site mAb AP5. In contrast to eptifibatide and TMV-2, cotreatment of TMV-7 with AP2 did not induce FcγRIIa-mediated platelet aggregation and the downstream activation cascade. Both TMV-2 and TMV-7 efficaciously prevented occlusive thrombosis in vivo. Notably, both eptifibatide and TMV-2 caused severe thrombocytopenia mediated by FcγRIIa, prolonged tail bleeding time in vivo, and repressed human whole blood coagulation indexes, whereas TMV-7 did not impair hemostatic capacity. Conclusions TMV-7 shows antiplatelet and antithrombotic activities resulting from a mechanism different from that of all other tested αIIb ß3 antagonists, and may offer advantages as a therapeutic agent with a better safety profile.

Immunostaining of glutamine synthetase is a sensitive and specific marker for diagnosing focal nodular hyperplasia in needle biopsy.

AIMS: Focal nodular hyperplasia (FNH) has characteristic histological features which may not be seen in needle biopsy specimens. We investigate the diagnostic role of glutamine synthetase (GS) in needle biopsy specimens. METHODS: Sixty-one hepatic tumours were categorised into 20 'definite' FNHs, 13 'probable' FNHs, and 28 cases without specific diagnosis. Needle biopsy specimens of 92 non-tumourous lesions, 25 well-differentiated hepatocellular carcinomas (WDHCCs), and 4 high-grade dysplastic nodules (HGDNs) and resection specimens of 10 macroregenerative nodules were also selected for immunohistochemical stain of GS for comparison. RESULTS: All 20 'definite' FNHs, nine 'probable' FNHs, and five cases without specific diagnosis expressed typical map-like staining pattern of GS. The demographic data of these five cases were similar to those of FNH. All cases of chronic hepatitis B and C, cirrhosis, macroregenerative nodule and peritumourous liver tissue showed normal pericentral/periseptal pattern. Fifteen of 25 WDHCCs and one HGDN showed diffuse pattern. Ten WDHCCs and two HGDNs showed negative staining. One HGDN showed mosaic pattern. CONCLUSIONS: Immunohistochemical staining of GS increases the diagnostic sensitivity of FNH in needle biopsy, especially in those without typical morphology. It also helps in differentiating FNH from other tumourous and non-tumourous lesions.

Is the sympathoexcitatory effect of yohimbine determined by brain yohimbine concentration?

Plasma noradrenaline and adrenaline concentrations, plasma renin concentration (PRC), and serum and brain yohimbine concentrations were measured in conscious Sprague-Dawley rats after the s.c. and i.v. injection of yohimbine. The s.c. and i.v. administration of 1 and 3 mg/kg of yohimbine (30 min post-injection) elicited equivalent and dose-related increases in plasma noradrenaline concentration. At 30 min post-injection, the 1 mg/kg dose given s.c. or i.v. did not increase plasma adrenaline concentration or PRC, whereas the 3 mg/kg dose caused comparable increases in plasma adrenaline concentration and PRC when given s.c. or i.v. Brain yohimbine concentration increased in a dose-related manner whereas serum yohimbine concentration was not significantly different 30 min after treatment with the 1 1 and 3 mg/kg doses regardless of the route of injection. Despite the fact that serum yohimbine concentration was 5-fold greater after i.v. injection as compared to s.c. administration (1 and 3 mg/kg doses), brain yohimbine concentrations were comparable after s.c. and i.v. injection and thus not dependent on either the route of administration or serum yohimbine concentration. The fact that the s.c. and i.v. injection of yohimbine lead to comparable dose-related increases in both brain yohimbine concentrations and neuroendocrine responses suggests that increased sympathetic outflow resulted primarily from an action of yohimbine at central, rather than peripheral, alpha 2-adrenoceptors. However, the data also are consistent with a purely peripheral prejunctional action of the 1 mg/kg dose and a combined central and peripheral action of the 3 mg/kg dose.

Captopril increases norepinephrine spillover rate in conscious spontaneously hypertensive rats.

These experiments were designed to test the hypothesis that the antihypertensive action of the converting enzyme inhibitor captopril in conscious spontaneously hypertensive rats is associated with an inhibition of norepinephrine release from peripheral sympathetic neurons. Radiotracer techniques were used to measure norepinephrine clearance and spillover rate into plasma. A single 30 mg/kg (s.c.) dose of captopril elevated norepinephrine spillover rate by 20 to 25 and 45 to 60% at 0.5- and 2-hr postinjection, respectively. At 2-hr postinjection, captopril (10 and 30 mg/kg s.c.) produced a dose-related fall in mean arterial pressure (MAP) and dose-related increase in norepinephrine spillover rate. The 30-mg/kg dose was more effective in decreasing MAP when given s.c. as compared to i.v. dosing. When equivasodepressor doses of captopril, hydralazine and prazosin were compared at 2-hr postinjection, the increases in norepinephrine spillover rate produced by captopril (44%) and hydralazine (68%) were not different. However, prazosin elevated norepinephrine spillover rate by 137%. Norepinephrine clearance was not altered by captopril. When MAP was lowered to the same extent (-17 to -23%) by 5 days of continuous treatment with captopril, enalaprilat and minoxidil, the increases in norepinephrine spillover rate (50-65%) were not different in the three treatment groups. In conclusion, these data do not support the hypothesis that captopril lowers blood pressure by inhibiting the neuronal release of norepinephrine.

[Clinical experience of nerve-sparing radical prostatectomy].

A total of 18 patients underwent nerve-sparing radical prostatectomy for clinical stage B1 or B2 prostatic cancer. An operation was performed according to the modified technique originally described by Walsh and associates. The operative technique involved three steps: 1) accurate ligation of dorsal vein complex, which makes a relatively bloodless field and makes it possible to dissect the lateral pelvic fascia from the prostate; 2) the incision in the lateral pelvic fascia is made anterior to the neurovascular bundle; 3) the lateral pedicle is divided close to the prostate. There were no major intraoperative complications such as rectal perforation or ureteral injury. The mean blood loss was 802 g (340-1600 g) and the average duration of surgery was 173 minutes. Eleven patients had no blood transfusions. Postoperatively, there was a wound infection in one case. Mild bladder neck contracture in one case responded to single dilatation. Sexual function was evaluated in 16 of the patients who have been followed for more than three months and who had not received hormone therapy postoperatively. Of 16 patients 6 (37%) had return of erectile function. Return of erections required 3-15 months (average 9 months). Patients under 70 years old had a higher incidence (80%) of return of erections than those over 70 years old. Four of the 6 patients had tumor involvement confined to the prostate. Initially most patients had significant amounts of stress incontinence. This resolved within the first or second postoperative month. Finally 4 had slight stress urinary incontinence but no patients had total incontinence. The results suggest that nerve-sparing radical prostatectomy is an anatomically safe approach. It can contribute to the quality of life in men at a stage when it is still curable.

[Clinical experience with the Kock continent ileal urinary reservoir].

From May 1985 through July 1987, 22 patients underwent Kock continent ileal reservoir for urinary diversion. There were 19 males and 3 females, between 38 and 82 years old (mean age 63.1 years). A one-stage radical cystectomy and Kock pouch construction were performed in 21 patients. One patients was converted from standard ileal conduit to this new reservoir. The keys to success of the Kock pouch are creation and maintenance of the nipple valve to prevent reflux and to ensure continence. Mesenteric fat is removed with CUSA for 8 cm along the afferent-efferent limbs of the pouch and exclusion of mesentery is limited for only 3-4 cm. This important modification will ensure adequate ileal intussusception and vascular supply to the valves. To prevent eversion and prolapse, the nipple valve is anchored to the wall of reservoir. A strip of sauvage filamentous Dacron serves as a collar to fix the afferent-efferent limbs to the pouch. There were 2 postoperative deaths and two major early complication: 1 acute renal failure and 1 intestinal fistula, both of which were treated conservatively. Late complications occurred in 6 patients. Of these 6 patients, 1 required reoperation and revision of the continence valve mechanism and 1 required hospitalization for entero-pouch fistula. Serum electrolytes and vitamin B12 remained normal in all patients. Patients perform self-catheterization every 4-6 hours during the day and once at night for volumes ranging up to 1,000 ml. The end result in 19 of 20 patients was excellent.(ABSTRACT TRUNCATED AT 250 WORDS)

[Transurethral ureterolithotripsy using a rigid ureteroscope].

Eighty patients with ureteral stones underwent transurethral ureterolithotripsy using a rigid ureteroscope. In 68 of the patients (85%), the stones were removed successfully. Most of the 12 failures were removed by a percutaneous approach. The main complications of transurethral ureterolithotripsy were high fever (35%), ureteral injury (10%) and ureteral stricture (1.6%). Ureteroscopic procedures are thought to be useful in stone removal and diagnostic evaluation of abnormality of upper urinary tract.

[Penile implantation surgery for organic impotence due to radical cystectomy or prostatectomy].

Implantation surgery was performed twelve times in eleven patients with organic impotence, mainly due to radical cystectomy and prostatectomy against malignancy, between March, 1982 and April, 1987. A self-contained type prosthesis (AMS Hydroflex(TM] was used in 7 cases, reservoir type inflatable prosthesis (AMS 700TM) in 2, malleable semirigid type (ESKA-Jonas Silicon Silver(TM) Trimming Tip Version) in 2, and nonmalleable semirigid type (Fuji system Finney type) in 1 case. In the last case, the prosthesis was replaced by AMS Hydroflex 4.5 years later at patient's wish. Excellent results and good patients' acceptance were gained with inflatable-type prosthesis (AMS 700 and Hydroflex) in 7 out of 8 cases (88%), whereas concealment problems were produced by semirigid type prosthesis (Finney and Jonas). Experience with AMS Hydroflex penile implantation is reported for the first time in the Japanese literature. Intraoperatively, it was sometimes difficult to implant a pair of Hydroflex rods into both of the corpus cavernosum. Postoperative perineal pain was almost constantly seen and in one patient, penile edema continued for three weeks and subsided spontaneously in two months. In another patient, the length of the prosthesis (15 cm) was short, and exchange to the longer one (17 cm) was necessary. In this patient, the longer Hydroflex caused erosion of the glans to necessitate its removal on one side. From our experience, the diameter (11 mm) of the Hydroflex seems to be too big for the average Japanese patient. The operative procedures and results of each kind of the prostheses are briefly discussed.

Nonprotein sulfhydryl compounds in canine gastric mucosa: effects of PGE2 and ethanol.

By use of an in vivo canine chambered stomach preparation in which the gastric mucosa was partitioned into two equal halves, the effect of topical 16,16-dimethyl PGE2 (DMPGE2) (1 microgram/ml of perfusate) and 8% and 40% ethanol on tissue levels of nonprotein sulfhydryl compounds was assessed. Both DMPGE2 and 8% ethanol significantly increased (P less than 0.005) mucosal levels of nonprotein sulfhydryls when compared with corresponding mucosa bathed with saline alone. In contrast, mucosa bathed with 40% ethanol showed significantly decreased levels. If mucosa was bathed with DMPGE2 or 8% ethanol prior to exposing the stomach to 40% ethanol, this depletion in sulfhydryl compounds was not observed. Since other experimental observations have shown that exogenously administered prostaglandins and mild irritants (such as low-dose alcohol) can prevent gastric mucosal damage by necrotizing agents (such as high-dose alcohol), our findings are consistent with the hypothesis that nonprotein sulfhydryls may play a role in mediating gastric mucosal protection.

[Experimental and clinical studies on calcium urolithiasis: (I) Animal model for calcium oxalate urolithiasis using ethylene glycol and 1-alpha (OH) D3].

As calcium oxalate stones are the most important component in urolithiasis, an experimental model has to be designed to clarify the pathogenesis and aid in their prevention. Hyperoxaluria as well as hypercalciuria were produced in rats by administering ethylene glycol (0.5%, in drinking water administered ad libitum) and 1-alpha (OH) D3 (0.5 micrograms/rat given every other day), respectively, for three to four weeks. Neither drug alone produced stones efficiently as did the combination regimen of these two compounds. The occurrence of stones was 77.3%, and with only a moderate degree of renal functional impairment. Biochemical and histological data were obtained using this model.

Failure of 16,16-dimethyl PGE2 to prevent inhibitory effect of ethanol on sodium transport in canine gastric mucosa.

By use of an in vitro canine gastric mucosal preparation, we evaluated the effects of ethanol (2, 4, 6, and 8%, vol/vol) and indomethacin (2.2 X 10(-4)M), with and without 16,16-dimethyl PGE2 pretreatment, on net sodium transport (JNanet) (mucosal to serosal) across gastric epithelium. Although administration of 2 or 4% ethanol to the mucosal bathing solution had no appreciable inhibitory effects on sodium transport, 6 and 8% ethanol and indomethacin significantly inhibited JNanet when compared with untreated control mucosa. This effect was accompanied by inhibition of transmucosal potential difference (PD) and short-circuit current (Isc). In other mucosae exposed to dimethyl PGE2 (8 X 10(-6) M) in the serosal bathing solution, significant increases in JNanet, PD, and Isc were noted when compared with control mucosa. Addition of 6 or 8% ethanol to the mucosal solution of dimethyl PGE2-pretreated tissue resulted in significant decreases in PD, Isc, and JNanet below control values that were not significantly different from mucosa exposed to 6 and 8% ethanol without PG pretreatment. When indomethacin was added to the mucosal solution following dimethyl PGE2 pretreatment, only slight decreases in PD and Isc below control levels were observed, and the inhibitory effects on JNanet induced by indomethacin without such treatment were abolished. These findings suggest that stimulation of JNanet by prostaglandin may play a role in its ability to prevent indomethacin damage to gastric epithelium but does not appear to be of importance in mediating protection against ethanol damage.

[Ultrasound-guided renal cyst puncture and 95% ethanol instillation. Part 2: Morphological and functional alterations].

Ultrasound-guided renal cyst puncture was performed on 22 cysts which were then 95% ethanol instilled to prevent recurrence of cystic fluid. Cystic lesions disappeared on the ultrasonogram in the follow-up period of 3 to 28 months. On CT, cystic lesions became smaller size but did not disappear. Average CT numbers of the cyst were 8.75 +/- 3.83 before and 12.96 +/- 3.27 after ethanol instillation. The cystic wall became thicker. Caliceal distortion and/or pelvis compression by cystic lesions improved on IVP 2 to 3 days after ethanol instillation. The renal image on Tc-99m-DMSA scintigram showed morphological improvement and DMSA renal uptake rate increased slightly but significantly 2 to 4 weeks after ethanol instillation. There were no major complications with this procedure except for one case in which the tip of the catheter became stuck in the cyst and broke off when the catheter was removed. A slight local irritable pain was noticed in all cases. Half of the patients had hot flushes and/or somewhat drunken sense but these symptoms were only temporary. Antabuse phenomenon appeared in one case with concomitant use of a cephem antibiotics after ethanol instillation. This method of therapy is a safe non-surgical approach to treat renal cysts. 95% ethanol instillation in the cyst seems to prevent recurrence of cystic fluid.

Sodium transport in Rana pipiens gastric mucosa.

The transport properties of frog gastric mucosa in vitro have been reexamined in conditions analogous to those used in studies on mammalian systems in which net movements of sodium were observed. Net transport of sodium across frog gastric mucosa was not observed to occur when the mucosal surface was bathed with a well-buffered solution of near neutral pH, indicating that failure to demonstrate sodium transport across frog stomach in previous work could not be ascribed to the low pH value of the solution usually used as the mucosal fluid. Addition of 5 X 10(-4) M amphotericin B to the mucosal solution elicited net transport of sodium and an increase in short-circuit current. These findings indicate that sodium transport may contribute to the electrolyte physiology of frog gastric mucosa in some experimental conditions, and may limit the utility of the three-variable model proposed by Hogben.

Prevention of the inhibitory effects of aspirin on sodium transport in canine gastric mucosa by prostaglandin. Correlation with mucosal morphology.

Using an in vitro canine gastric mucosal preparation, this study evaluated the effects of 1 mM aspirin in a buffered Ringer solution (pH = 7.4), with and without concomitant prostaglandin (PG) treatment, on net sodium transport (mucosa to serosa) across gastric epithelium. Administration of aspirin to the mucosal bathing solution for 2 hr significantly decreased the potential difference (PD), short circuit current (Isc), and net sodium transport (net J-Na+) when compared with untreated control mucosa. In mucosa treated with 16,16-dimethyl PGE2 (8 X 10(-6) M) in the serosal bathing solution 40 min after aspirin exposure and for 80 min thereafter, the initial inhibitory effects on PD, Isc, and net J-Na+ induced by aspirin were completely reversed within 40 min of PG treatment, having returned to control values. Histologically, mucosa exposed to aspirin alone showed evidence of diffuse cellular injury involving 50-60% of the surface epithelium. In contrast, mucosa treated with prostaglandin in conjunction with aspirin exposure demonstrated damage involving only 20-30% of the epithelium. These findings suggest that stimulation of sodium transport by PG may play a role in mediating the cytoprotective effects of PGs against aspirin-induced gastric mucosal injury.

Effects of 16,16-dimethyl prostaglandin E2 on alkaline secretion in isolated canine gastric mucosa.

An isolated fundic mucosal preparation of dog stomach which is capable of exhibiting an alkaline secretion is described. A stable secretion was established 40 min to 1 hr after the mucosa was pretreated with the H2-antagonist cimetidine to block spontaneous acid output. Alkaline secretion decreased when Ca2+ was removed from the nutrient solution. This secretion was stimulated by dibutyryl cyclic GMP, but was not altered by acetylcholine, carbachol, or 16,16-dimethyl PGE2. Alkaline secretion from a similar antral mucosal preparation was stimulated by 16,16-dimethyl PGE2. We conclude that the 16,16-dimethyl PGE2-stimulated bicarbonate secretion previously demonstrated in in vivo canine fundic mucosa is not the result of a direct effect of PG on gastric mucosal cells and that an intact blood circulation or cholinergic innervation is required for this action to occur.

Parathyroid cysts with primary hyperparathyroidism: report of a case.

Cysts of the parathyroid glands are uncommon, and, moreover functioning parathyroid cysts that cause primary hyperparathyroidism are rare. Herein is reported a 53-year-old female with primary hyperparathyroidism accompanied by 2 parathyroid cysts, in one of which adenoma was noticed. Forty-two cases of parathyroid cysts were found in the Japanese literature. Twelve of them were in the hyperparathyroid state, but infarction of the adenoma lead to cystic degeneration in most of such cases and so the cyst wall were lined with adenoma cells. In only 2 cases including our case were the cyst walls lined with cuboid cells and the adenoma evident in the wall. The pathogenesis of our case seems to be a common embryonic defect or dilatation of vestigial remnants rather than a degenerative change of the adenoma.

Route of ethanol administration and gastric acid output during chronic conditions.

The effect of intravenous or intragastric ethanol on gastric secretion was determined in chronic ethanol-fed and matched control rats. In vivo, basal and histamine-stimulated acid outputs were inhibited by acute intragastric ethanol to a greater extent in chronic control rats than in ethanol-fed rats. In contrast, intravenous ethanol stimulated basal and potentiated histamine (H)-stimulated acid output (blocked by cimetidine but not atropine) in ethanol-fed rats but not in chronic control rats. Serum gastrin levels were not significantly altered by ethanol. In vitro, mucosal ethanol inhibited basal and H-stimulated acid secretion by mucosae from chronic control and ethanol-fed rats, but serosal ethanol did not significantly alter acid secretion. In conclusion, chronic ethanol intake results in higher acid outputs following acute exposure to intravenous or intragastric ethanol or in vitro exposure to mucosal ethanol as compared to studies using matched control rats.

Inhibition of active sodium transport by cytochalasin B in rat jejunum in vitro.

The effects of cytochalasin B on electrophysiological properties and sodium transport in rat jejunum in vitro are described. Stripped paired rat jejunal segments were maintained in Ussing chambers with Leibovitz's (L-15) tissue culture medium bubbled with 100% oxygen. L-15 medium contains galactose as the only sugar, and an assortment of amino acids and cofactors to nourish the tissue. Electrophysiological parameters of short-circuit current (Isc) and transepithelial potential difference could be maintained for up to 4 h in control tissues. Upon application of cytochalasin B (20 micrograms/ml), on the mucosal side, Isc and potential difference fell within 1 h from 1.93 +/- 0.12 to 1.09 +/- 0.14 (mean +/- S.E.) muequiv./cm2 per h and from 5 to 2.5 mV. Tissue resistance remained unchanged at approx. 110 omega X cm2 for up to 4 h. 22Na net flux was 4.1 +/- 0.9 muequiv./cm2 per h during the last control period and fell to zero within 1 h after cytochalasin B treatment. Transmission electron micrographs revealed no gross morphological changes at this dose. Absorptive junctional morphology was apparently not altered by cytochalasin B treatment, a finding which was consistent with the stable transepithelial electrical resistance observed during exposure to this drug. Active sodium transport processes coupled to hexose, amino acid, and chloride movements are all possible in L-15 medium. However, following exposure to 20 micrograms/ml cytochalasin B, all net sodium transport is completely inhibited. The data are consistent with the hypothesis of a common regulator for active sodium transport processes which is modulated through structural changes in cytoskeletal organization.

Acute effect of ethanol on metabolite concentrations of dog pancreas in vivo.

Sections of dog pancreas were freeze-clamped before and 1 hr after oral administration of 1 g/kg of ethanol in anesthetized, respirated, 24-hr-fasted animals, and multiple metabolites were determined in the perchloric acid extract of the frozen tissue. In spite of the fact that the pancreas contained little or no alcohol dehydrogenase activity (less than 0.01 IU/g of tissue), significant metabolite changes did occur. Although arterial oxygenation was constant and adequate (pO2 = 100 +/- 7 mM Hg) there was a significant 1.7-fold rise in L-lactate and fall in the cytoplasmic free [NAD+]/[NADH] ratio from 719 +/- 87 to 453 +/- 88 after ethanol. Except for a tendency for L-malate and L-alpha-glycerolphosphate to parallel the rise in L-lactate, there was little consistent disturbance in the remainder of the glycolytic metabolites (glucose, glucose 6-phosphate, pyruvate, 2-ketoglutarate, citrate, 3-phosphoglycerate, etc.) or in high energy intermediates and related compounds (ATP, creatine phosphate, ADP, Pi, creatine). There was, however, an unexpected and significant fall in the levels of the major transaminating amino acids, L-glutamate, L-aspartate, and L-alanine. The results can be only partially explained by an influence of blood-borne metabolites and imply significant effects of ethanol on the metabolism of the pancreas in vivo not directly mediated through alcohol dehydrogenase. Evidence is presented suggesting that both L-alanine and L-aspartate aminotransferases are functioning near equilibrium in the pancreas in vivo.