Urine xanthine oxidase activity in urinary tract infection.

Xanthine oxidase (XO) activity was found to be negligible in sterile human urines (less than 480 units, as presently defined, per litre). Significant XO activity was found in all urines containing more than 10(5) bacteria/ml, except for urines infected with Staphylococcus aureus, in which XO activity ranged from 347 to 714 units per litre. Plasma XO is not transferred to the urine, as demonstrated by the negligible XO activity found in sterile urines from patients with raised plasma XO activity. Determination of urinary XO activity is a suitable procedure for the detection of urinary tract infection.

Use of tolonium chloride in the diagnosis of malignant gastric ulcers.

Peroral staining with tolonium chloride (toluidine blue) was performed in 45 patients with suspected gastric ulcer disease. During endoscopy, 19 of 21 malignant ulcers and one of 15 benign ulcers were stained. Following surgery, 18 of 21 malignant ulcers found in the surgical specimens were stained. Eleven patients with benign ulcers underwent surgery and none of these ulcers were found to be stained in the surgical specimens. Normal gastric mucosa and areas of gastritis appeared unchanged. The data suggest that tolonium chloride staining prior to endoscopy or surgery seems to be helful in differentiating between minute benign and malignant gastric ulcers.

Serum xanthine oxidase in jaundice.

Serum xanthine oxidase activity was measured by a radiochemical method in 137 consecutive patients with jaundice of varying etiology and in 40 non-jaundiced patients with liver or other disease. Serum xanthine oxidase was markedly increased, up to 50 times the upper normal limit (mean + 2 S.D.), in 32 out of 34 patients with infectious hepatitis. A slight elevation of serum xanthine oxidase, up to twice the upper normal limit, was found in 2 out of 49 patients with extrahepatic obstructive jaundice and in 4 out of 20 patients with chronic renal failure. In comparison to serum glutamic-oxaloacetic transaminase and lactate dehydrogenase serum xanthine oxidase appeared to be the more sensitive and specific indicator of acute hepatocellular damage.

Cyclic AMP decreases the availability of 5-phosphoribosyl-1-pyrophosphate and decelerates de novo purine synthesis in rat hepatocytes.

Cyclic adenosine monophosphate (cAMP) was found to decrease the availability of 5-phosphoribosyl-1-pyrophosphate (PRPP) and to decelerate the rate of de novo purine synthesis in suspensions of adult rat hepatocytes. Glucagon did not affect these parameters. The glucagon antagonist des-His1[Glu9]glucagon amide (DHGA), and the protein kinase C activator 1,2-dioctanoyl-sn-glycerol (DOG) were also found to lower PRPP availability. Incubation of the hepatocytes with dbcAMP or with DHGA, did not alter the activity of PRPP synthetase in the hepatocyte lysates, indicating that the above effects are not mediated through the activity of this enzyme. The possibility that the decrease in PRPP availability reflects increased consumption associated with accelerated pyrimidine synthesis is discussed. The decelerated rate of de novo purine synthesis is probably secondary to the decreased PRPP availability.

Fiberoptic-guided CO2 laser for harvesting of the internal mammary artery.

OBJECTIVE: The internal mammary artery is the preferred conduit in coronary artery bypass grafting. Although most centers use electrocautery to dissect the internal mammary artery, it has several disadvantages. The purpose of this study in a canine model was to evaluate and compare a fiberoptic CO2 laser device versus electrocautery for harvesting the internal mammary artery. MATERIAL AND METHODS: In ten mongrel dogs, both internal mammary arteries with their surrounding pedicles, were dissected from the thoracic wall, using a low-current electrocautery for one artery and a continuous wave, fiberoptic-guided CO2 laser (13 watts) for the contralateral vessel. Blood flow through the vessels was measured immediately after dissection. RESULTS: Mean flow through the laser dissected arteries was 71.3 +/- 23.7 ml/min versus 52.9 +/- 16.5 ml/min in those dissected using electrocautery. Histological examination of the chest wall specimens dissected with electrocautery showed the presence of necrosis, edema and hemorrhage surrounding the muscle, while the specimens dissected with the laser revealed only a narrow area of burn on the surgical margins of the muscle. The laser-assisted dissection was more accurate, as easy, and almost as fast as with the use of electrocautery. CONCLUSIONS: Stripping of the internal mammary artery with the fiberoptic CO2 laser offers a promising alternative to electrocautery. Owing to its greater accuracy, the laser technique may reduce the likelihood of damaging the endothelial lining of the dissected vessel. By reducing the degree of soft tissue damage, the CO2 laser may also lower the incidence of sternal wound infection and reduce postoperative chest wall pain and dysesthesia.

Increased serum angiotensin-converting enzyme activity and plasma angiotensin II levels during pregnancy and postpartum in the diabetic rat.

OBJECTIVE: The renin-angiotensin system (RAS) plays an important role in the regulation of blood pressure, electrolyte balance and renal function in normal human pregnancy. The present study was designed to assess various components of the RAS and renal function during pregnancy and immediately after pregnancy in the streptozotocin (STZ)-diabetic rat. METHODS: Pregnant Wistar rats were allocated to three groups: I-control, non-diabetic rats (n=24), II-STZ-diabetic rats (STZ 55 mg/kg body weight, i.v. on day 10 of pregnancy, n=24), III-diabetic rats, as above, treated with insulin (4 units/day, s.c. n=21). On days 17-18 of pregnancy, or within 24 hours after delivery, the rats were sacrificed and the various components of the RAS were determined. RESULTS: Urinary protein excretion (UP) and creatinine clearance(CCr) were greater in group II, four days after STZ, than in group I (UP: I-7.6+/-2.8, II-18.6+/-6.3 mg/24-hour, p<0.001, CCr: I-1.04+/-0.33, II-2.38+/-0.7 ml/minute, p<0.001). Mean (+/-SD) serum angiotensin-converting enzyme (ACE) activity and plasma angiotensin II(Ang II) levels at days 17-18 of pregnancy were greater in the untreated diabetic rats than in control pregnant rats (ACE: 163+/-18 vs. 111+/-21 nmol/ml/minute, p<0.001, Ang II: 115+/-45 vs. 43+/-10 pg/ml, p<0.005). Postpartum serum ACE activity and plasma Ang II levels were greater in group II (ACE: I-123+/-14, II-142+/-24, III-108+/-21 nmol/ml/minute, p<0.01, Ang II: I-56+/-38, II-148+/-62, III-38+/-17 pg/mI, p<0.001). ACE activity in the lung was greater, whereas the activity in the renal cortex was less, in group II than in group I. Kidney weight in untreated diabetic rats was greater than in the other two groups. CONCLUSION: Increased serum ACE activity during pregnancy and postpartum in the untreated diabetic rat is associated with enhanced serum Ang II levels, which may contribute to increased protein excretion and renal hypertrophy.

A new technique for vascular anastomoses.

Vascular anastomoses are invariably performed manually and may be difficult technically particularly in smaller calibre vessels. This may be even more pronounced when an emergency situation exists and a surgeon relatively inexperienced in vascular surgery has to deal with the problem. A technique is described allowing for rapid anastomosis of vessels ranging upwards from a diameter of 2.5 mm using incomplete adjustable metal rings. The technique is simple and can be applied by surgeons with minimal vascular training. This could be extremely useful in the emergency situation, particularly when critical ischemia exists. Also, anastomoses of small calibre vessels such as in arterio-venous fistula may be more simply performed by the aid of the described rings.

Elevated serum xanthine oxidase activity following biliary tract and gastric surgery.

The activity of serum xanthine oxidase, an enzyme mainly found in the liver, was determined in a random series of patients who underwent abdominal surgery of varying severity. Enzyme activity rose markedly on completion of operation in almost all patients undergoing biliary tract and gastric surgery, but not in those undergoing surgery of other abdominal organs, Serum glutamic oxaloacetic transaminase level rose to a smaller degree and in a smaller proportion of the patients. Elevation of the serum level of both enzymes following biliary and gastric surgery reflects hepatocellular damage caused by surgical trauma to the liver.

Major surgery in leukemic patients.

During the last ten years, 15 major operations have been performed in our ward on 14 patients with leukemia. Nine had an uncomplicated postoperative course, two succumbed to overwhelming postoperative infections, another two died from cardiovascular complications and one from carcinomatous spread. There were no wound-related complications and no granulocyte or platelet transfusions were necessary. It is concluded that major surgery should not be avoided in patients solely because of the presence of a leukemic process.

Increased leukocyte adhesiveness/aggregation and tissue leukostasis following surgical trauma.

The purpose of the present study was to document the increased leukocyte adhesiveness/aggregation (LAA) and tissue leukostasis that follow surgical trauma. We found that following major abdominal surgery, the percentage of aggregated leukocytes in the peripheral blood increased from 8.6 +/- 7 to 21.7 +/- 11.5 (p < 0.001), while the respective values for patients undergoing minor surgery were 3.7 +/- 2.4 and 19.7 +/- 7.6% (p < 0.001). The state of LAA was also determined in eight dogs after partial collectomy and four controls. A clear increment in the degree of tissue leukostasis (especially in the spleen, liver and lungs) was noted in the operated as compared to the control animals. In addition, a significant correlation was found between the state of LAA, determined in the venous (p = 0.0004) and arterial (p = 0.002) blood of these animals and the degree of tissue leukostasis. We conclude that a state of increased LAA in the peripheral blood is induced by surgical trauma and that this increased LAA correlates with tissue leukostasis.