Techniques for better suturing

Suturing techniques enhancing the accuracy of suture placement and reducing the forces on the tissue being sutured were evaluated in six surgeons, each with 6 years' surgical experience. The accuracy was assessed by the distance between the actual and designated needle exit sites. Force was expressed in terms of the torque on the needle holder using a maximum of the torques (max. F), maximum derivative (dF/dt) and integral (IF). The effects of four factors (suturing techniques) on suturing were evaluated: (1) placement of the needle holder on the needle; (2) inclining the tissue at needle entrance, as is commonly done by elevating with forceps (unnoted role of the forceps); (3) adjustment of the needle's exit during suture placement, as is unknowingly employed in practice, and (4) variation between individual surgeons. All these factors affected the accuracy and force of suturing. Gripping the needle closer to the tip strongly reduced the max. F, dF/dt, and IF per time, as did inclining the tissue. Adjustment of exit improved accuracy, but has the potential for causing avoidable tissue injuries. Differences between surgeons suggest the necessity of addressing fundamental surgical techniques and formally incorporating them into the training programme.     

Nitric oxide modulates Ca(2+) channels in dorsal root ganglion neurons innervating rat urinary bladder.

The effect of a nitric oxide (NO) donor on high-voltage-activated Ca(2+) channel currents (I(Ca)) was examined using the whole cell patch-clamp technique in L(6)-S(1) dorsal root ganglion (DRG) neurons innervating the urinary bladder. The neurons were labeled by axonal transport of a fluorescent dye, Fast Blue, injected into the bladder wall. Approximately 70% of bladder afferent neurons exhibited tetrodotoxin (TTX)-resistant action potentials (APs), and 93% of these neurons were sensitive to capsaicin, while the remaining neurons had TTX-sensitive spikes and were insensitive to capsaicin. The peak current density of nimodipine-sensitive L-type Ca(2+) channels activated by depolarizing pulses (0 mV) from a holding potential of -60 mV was greater in bladder afferent neurons with TTX-resistant APs (39.2 pA/pF) than in bladder afferent neurons with TTX-sensitive APs (28.9 pA/pF), while the current density of omega-conotoxin GVIA-sensitive N-type Ca(2+) channels was similar (43-45 pA/pF) in both types of neurons. In both types of neurons, the NO donor, S-nitroso-N-acetylpenicillamine (SNAP) (500 microM), reversibly reduced (23.4-26.6%) the amplitude of I(Ca) elicited by depolarizing pulses to 0 mV from a holding potential of -60 mV. SNAP-induced inhibition of I(Ca) was reduced by 90% in the presence of omega-conotoxin GVIA but was unaffected in the presence of nimodipine, indicating that NO-induced inhibition of I(Ca) is mainly confined to N-type Ca(2+) channels. Exposure of the neurons for 30 min to 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 microM), an inhibitor of NO-stimulated guanylyl cyclase, prevented the SNAP-induced reduction in I(Ca). Extracellular application of 8-bromo-cGMP (1 mM) mimicked the effects of NO donors by reducing the peak amplitude of I(Ca) (28.6% of reduction). Action potential configuration and firing frequency during depolarizing current pulses were not altered by the application of SNAP (500 microM) in bladder afferent neurons with TTX-resistant and -sensitive APs. These results indicate that NO acting via a cGMP signaling pathway can modulate N-type Ca(2+) channels in DRG neurons innervating the urinary bladder.     

Clinical results and in vivo valve function after implantation of a Bicer valve prosthesis in the aortic position

Between December 1981 and June 1987, 71 patients underwent aortic valve replacement with a Bicer monostrut tilting disc prosthesis. Clinical results and in vivo function of the artificial valve were assessed. The average age of the 71 patients at the time of operation was 51.3 +/- 11.5 years. The hospital mortality rate was 2.8% (two patients) and there were no further deaths during a mean (+/- SD) follow-up period of 2.4 +/- 1.6 years (range 1 month to 5.5 years) after surgery. There was also no occurrence of thromboembolism or valve dysfunction. Function of the Bicer valve prosthesis was assessed in 17 patients: 5 with a 21 mm valve, 7 with a 23 mm valve and 5 with a 25 mm valve. Examination was performed on average 10.3 +/- 8.1 months after surgery. Valve function was examined at rest and during exercise performed with a bicycle ergometer. Pressure gradients at rest were low: 21 mm valve = 8 mm Hg, 23 mm valve = 3 mm Hg and 25 mm valve = 2 mm Hg; the gradients during exercise were 11, 8 and 8 mm Hg, respectively. The valves had the following effective orifice area at rest: 21 mm valve = 1.54 cm2, 23 mm valve = 4.20 cm2 and 25 mm valve = 3.76 cm2; during exercise, the respective areas were 1.57, 3.48 and 3.01 cm2. These valves are deemed to be sufficiently wide for effective valve function. Aortographic observation indicated mild regurgitation that was within reasonable limits and posed no problem.(ABSTRACT TRUNCATED AT 250 WORDS)     

A case of aortic intimal sarcoma manifested with acutely occuring hypertension and aortic occlusion

Summary Primary tumor of the aorta is extremely rare. An instance of aortic intimal sarcoma, namely fibromyxosarcoma, which extended from the beginning of the descending aorta to 7 cm above the abdominal bifurcation, with clinical evidence of acutely occurring hypertension, arterial embolism of the lower extremities, renal infarction, and aortic occlusion in a 50-year-old male is reported. The tumor was limited to the intima and composed of spindle-shaped tumor cells with abundant myxoid extracellular matrices. The tumor cells were negative for Factor VIII, Desmin, or Myoglobin, but were positive for Vimetin or Factor XIIIa in immunoperoxidase studies. An electron microscopic examination revealed a large amount of rough endoplasmic reticulum in the cytoplasm. Parenchymal metastases were observed in both the lungs and thoracic vertebrae. A review of literature on the clinical and pathological aspects of the tumor was made.     

Metastatic gastrinoma to the liver 20 years after primary resection

Gastrinoma is a rare endocrine tumor that is frequently associated with liver metastasis. The liver metastasis is usually seen simultaneously or soon after a primary operation. A 47-year-old woman who had had a total gastrectomy 20 years earlier developed liver metastasis. An interval of this length between surgery and metastasis is extremely rare. The total gastrectomy prevented the patient from developing the usual symptoms of hypergastrinemia that would have enabled early diagnosis of the metastasis. Laboratory examinations on admission revealed a high serum gastrin concentration (1500 pg/ml). Computed tomography showed an irregularly enhanced mass lesion with an uneven, low-density central area in the right anterior inferior segment of the liver. An extended right hepatectomy was performed. Intraoperative ultrasonography showed no abnormalities in the remnant pancreas. Examination of the cut surface of the specimen revealed a yellow, firm, elastic tumor, 55 mm in diameter. The interior of the tumor appeared necrotic. Histopathologically, the tumor was composed of cells with hyperchromatic, dysplastic nuclei arranged in a trabecular pattern with nest formation. Gastrin staining was positive. A histologic diagnosis of metastatic gastrinoma was made. The patient's gastrin concentration returned to normal and she was well at 2-year follow-up. Received: August 19, 1999 / Accepted: January 28, 2000     

Pharmacological profile of a new orally active growth hormone secretagogue, SM-130686.

SM-130686, an oxindole derivative, is a novel orally active GH secretagogue (GHS) which is structurally distinct from previously reported GHSs such as MK-677, NN703 and hexarelin. SM-130686 stimulates GH release from cultured rat pituitary cells in a dose-dependent manner. Half-maximum stimulation was observed at a concentration of 6.3+/-3.4 nM. SM-130686-induced GH release was inhibited by a GHS antagonist, but not by a GH-releasing hormone antagonist. SM-130686 dose-dependently inhibited the binding of radiolabeled ligand, (35)S-MK-677, to human GHS receptor 1a (IC(50)=1.2 nM). This indicates that SM-130686 stimulates GH release through the GHS receptor. The effect of a single oral administration of SM-130686 on GH release in pentobarbital-anesthetized rats was studied. After treatment with 10 mg/kg SM-130686, plasma GH concentrations measured by radioimmunoassay significantly increased, reaching a peak at 20-45 min, and remained above baseline during the experimental period (60 min). The anabolic effect of repetitive SM-130686 administration was studied in rats. Rats received 10 mg/kg SM-130686 orally twice a day and were weighed every day for 9 days. At day 9 there was a significant increase in both the body weight and the fat free mass (19.5+/-2.1 and 18.1+/-7.5 g respectively). Serum IGF-I concentration was also significantly elevated 6 h after the last dose of SM-130686. An endogenous GHS ligand for the GHS receptor has recently been identified from stomach extract and designated as ghrelin. The GH-releasing activity in vitro relative to ghrelin (100%) was about 52% for SM-130686. It is likely that SM-130686 is a partial agonist for the GHS receptor. In summary, we describe here an orally active GHS, SM-130686, which acts through the GHS receptor. Repetitive administration of SM-130686 to rats, similar to repetitive administration of GH, significantly increased the fat free mass by an amount almost equal to the gain in body weight.     

Asymptomatic chronic intestinal ischemia caused by idiopathic phlebosclerosis of mesenteric vein

Phlebosclerosis of the mesenteric vein is a rare condition causing chronic intestinal ischemia, it has only been reported in Japan. A 56-year-old man with liver cirrhosis and hepatic tumor presented with phlebosclerosis of mesenteric vein without any abdominal symptoms. He was admitted for examination of suspected hepatic tumor. Abdominal plain x-ray films and computed tomography revealed calcification of the mesenteric vein. Barium enema revealed narrowing and thumbprinting from the cecum to transverse colon. On colonoscopic examination, blue-black vessels were visible in the terminal ileum, and hyperemic nodular mucosa with small irregular ulcers surrounded by dark purple mucosa was found from the cecum to transverse colon. The etiology of mesenteric vein phlebosclerosis is unknown, although a physical mechanism rather than inflammatory changes appear to be involved in this rare and usually progressive condition of chronic intestinal ischemia.