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Biomedical subjects

M Prieto

Publications and source records attributed to M Prieto.

At least 145 records · Page 8Linked to original sources
PubMed1990

Purification and characterization of a calicivirus as the causative agent of a lethal hemorrhagic disease in rabbits.

The causative viral agent of a lethal rabbit hemorrhagic disease has been purified and characterized. In negative-stained preparations, the virions were icosahedral, measured 27 to 35 nm in diameter, were without an envelope, and showed 10 peripheral cup-shaped depressions. The major structural protein was 60 kilodaltons, which constitutes a unique characteristic of the Caliciviridae.

Animals↗
PubMed1990

Biovars of coagulase-positive staphylococci isolated from bovine mastitic milk.

Fifty strains of coagulase-positive staphylococci associated with bovine mastitis were biotyped. Of them, 20 were identified as biovar C (cattle & sheep), 17 as biovar B (poultry & swine), 2 as biovar D (hares) and 1 as biovar F (pigeon & fox). Of the remaining strains, 2 were closely related to human biovar A, 2 failed one property to be classified as biovar B, 3 shared properties of biovars B and D and 3 could not be identified. Bovine strains belonging to biovar C formed an heterogeneous group showing differences in crystal violet growth type and production of alpha haemolysin. Only strains associated with biovar A were Tween 80 positive. The highest incidence of lytic reactions amongst all biovars was with phages 42 E (III) and 102 (IV). Antibiotic resistance was most frequently found in biovar C (65%). The 2 strains in biovar D, one classed as biovar C and one as intermediate, were enterotoxigenic (C or D toxins).

Animals↗
PubMed1989

Prospective assessment of donor blood screening for antibody to hepatitis B core antigen as a means of preventing posttransfusion non-A, non-B, hepatitis.

The relationship between donor status for antibody to hepatitis B core antigen and the occurrence of non-A, non-B posttransfusion hepatitis in the recipient was prospectively studied in 112 patients undergoing open-heart surgery who were followed for 6.5 months after surgery. Non-A, non-B posttransfusion hepatitis occurred in five (7.93%) of 63 patients who had received at least one anti-HBc-positive blood unit compared to seven (14.28%) of 49 patients who received anti-HBc-negative blood only. Statistical analysis revealed that the incidence of non-A, non-B posttransfusion hepatitis was independent of the use of blood positive for anti-HBc. Based upon these results and the high prevalence (17.3%) of anti-HBc among our blood donor population, the exclusion of anti-HBc-positive blood does not seem appropriate to achieve a reduction in the incidence of non-A, non-B posttransfusion hepatitis.

Blood↗
PubMed1989

Characteristics and regulation of a high conductance anion channel in GBK kidney epithelial cells.

Single anion selective channels have been studied in membrane patches of GBK cultured epithelial cells from bovine kidney. High conductance anion channels are exclusively observed in excised patches after holding them at membrane potentials larger than +/- 30 mV for seconds or minutes. Once activated, the channels show a steep voltage dependence, complex gating properties and multiple conductance levels. The major unit conductance is 300 pS (+/- 28; n = 12) in symmetrical chloride. The discrimination among different anions and between anions and cations is poor. The activity of the channels remains unchanged after addition of 10 mM EGTA to the cytoplasmic face of the membrane, but it is irreversibly inhibited by application of 1 mM 4-acetamido-4'-isothiocyano-2,2'-disulphonic acid stilbene (SITS). Neither permeabilization of the cell membrane to Ca2+ using the Ca2+ ionophore A23187, treatments which increase the cyclic AMP content of the cells, nor hypoosmotic shocks, activate high conductance anion channels in cell-attached patches in which the activity of the channels is subsequently demonstrated upon patch excision. These results indicate that high conductance anion channels with the same characteristics as those reported in different cell types are present in GBK cells and suggest that the physiological role for these molecular entities may be different from those previously postulated.

Animals↗
PubMed1989

Method for home monitoring of urinary amylase after pancreas transplantation.

Urinary amylase activity (UAA) is used for diagnosis of rejection in bladder-drained pancreas grafts. Unfortunately, most rejection episodes occur after the patient has been discharged. In those cases, an early diagnosis is often difficult, and a method for home UAA monitoring is needed. We have developed a method that can be used for this purpose. The method, based on Kodak dry-film technology, is shown to have good response to the wide range of UAA seen in these patients compared with responses to standard laboratory kinetic methods. The analysis (performed by the patient) involves 1) collecting urine for 24 h in a 4-L container, 2) diluting the urine with tap water to a total urine of 4 L, and 3) placing a drop of this dilution onto a slide. The slide is read by a handheld spectrophotometer that displays the UAA in secreted units per hour. The reliability of this system has been tested for wide changes of urine pH, volume of the drop applied to the slide, and tap water from different sources. Temperature coefficients have been determined to correct changes in ambient temperatures. The final handheld prototype is being developed based on these preliminary studies. This device could be of benefit for the early diagnosis of rejection episodes in recipients of bladder-drained pancreas grafts after hospital discharge.

Amylases↗
PubMed1988

Diagnosis of malignant ascites. Comparison of ascitic fibronectin, cholesterol, and serum-ascites albumin difference.

The ascitic fluid concentrations of cholesterol and fibronectin and the serum-ascites albumin difference were compared with two conventional tests of ascitic fluid, total protein and LDH, in their diagnostic ability for detection of malignancy in ascitic samples from 69 patients with ascites: 54 with ascites due to liver disease and 15 whose ascites was caused by peritoneal metastases. Sixteen cirrhotic patients with superimposed hepatocellular carcinoma in whom ascites was of uncertain etiology were considered separately. The mean ascitic fluid total protein, LDH, cholesterol, and fibronectin values in the peritoneal metastases group were 3.70 +/- 1.20 g/dl, 247.26 +/- 148.14 units/liter, 109.06 +/- 29.85 mg/dl, and 91.57 +/- 41.52 micrograms/ml, respectively, and all were significantly higher than the corresponding values in the liver disease group (P less than 0.001), which were 1.37 +/- 0.59 g/dl, 75.40 +/- 110.70 units/liter, 23.75 +/- 11.22 mg/dl, and 31.86 +/- 10.51 micrograms/ml, respectively. Mean serum-ascites albumin difference in the peritoneal metastases group was 0.62 +/- 0.38 g/dl, which was significantly different from the corresponding value in the liver disease group (1.92 +/- 0.41 g/dl, P less than 0.001). Both ascitic cholesterol above 46 mg/dl and an ascitic fibronectin concentration greater than 50 micrograms/ml had high diagnostic accuracy (97%) for malignancy, being higher than that achieved using a serum-ascites albumin difference under 1.1 g/dl and an ascitic total protein above 2.5 g/dl, which had accuracies of 94% and 93%, respectively. Ascitic fluid LDH was the least reliable test. No differences in the ascitic fluid analysis were found between cirrhotic patients with and without hepatocellular carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascites↗
PubMed1988

Behaviour of Staphylococcus aureus strains, producers of enterotoxins C1 or C2, during the manufacture and storage of Burgos cheese.

Burgos cheese was manufactured from pasteurized ewes' milk inoculated with Staphylococcus aureus strains FRI 137 and FRI 361, at levels of ca 10(3) and 10(5) cfu/ml and stored at 4 degrees, 10 degrees and 15 degrees C and at room temperature (10 degrees-15 degrees C). Populations of Staph. aureus and mesophilic aerobes, pH, and production of thermonuclease and enterotoxins C1 and C2 were investigated. Aerobic counts increased during cheese-making and storage. With both test strains, important growth was observed only during the storage period, the larger levels corresponding to the higher temperatures. Although Staph. aureus strains attained populations of over 10(8) cfu/g, no enterotoxin was detected. Strain FRI 361 reached 10(7) cfu/g without production of a detectable amount of thermonuclease. With strain FRI 137, the minimal population associated with enzyme activity was influenced by the inoculum size. Staphylococcus aureus counts are better indicators of staphylococcal growth in Burgos cheese than the thermonuclease test.

Aerobiosis↗
PubMed1987

Experimental and clinical experience with urine amylase monitoring for early diagnosis of rejection in pancreas transplantation.

Pancreas allograft rejection in dogs with pancreaticocystostomy can be predicted in advance of hyperglycemia by monitoring the urinary amylase (UA) concentration (U/L): In initial experiments, UA values declined to less than 1000 1.3 +/- 0.2 days before hyperglycemia in nonimmunosuppressed dogs, 3.3 +/- 1.0 days in dogs treated with cyclosporine (CsA), and 9.3 +/- 0.7 days in dogs treated with CsA, azathioprine (Aza), and prednisone (triple therapy). Autotransplanted control dogs maintained high urine amylase concentrations indefinitely (mean 125,544 +/- 36,931). In a subsequent experiment, in 19 dogs with bladder-drained pancreas allografts on CsA only for prophylactic immunosuppression, a five-day course of antirejection treatment with Aza (5.0 mg/kg) and antilymphocyte globulin ALG (1 mg/kg) was started in group A (n = 10) when a raise in serum glucose was detected, and in group B (n = 9) when a drop of UA below 1000 was observed. The functional allograft survival rate was 9.2 +/- 0.5 days in group A (treatment started after hyperglycemia) and 29.0 +/- 5.7 days in group B (treatment started after drop in UA) (P = .002). The UA dropped in all dogs before hyperglycemia, at a mean of 2.7 days in group A and 20.8 days in group B. Clinically, 8 patients received a whole cadaver pancreas transplant with urinary drainage of the exocrine secretions. All were followed with UA monitoring. Three recipients lost the grafts for technical reasons. Three recipients lost the grafts for technical reasons. One had a primary non-function and UA was below 1000 U/24 hr; two developed abscesses and the grafts were removed while functioning with high UA values. Five grafts are currently functioning; 3 recipients had no rejection episodes and their UA values ranged from 30,000 to 100,000 U/24 hr during their entire postoperative course. The other two had rejection episodes. In both cases UA decreased to baseline levels 1 and 4 days in advance of the hyperglycemia. After antirejection treatment UA rose again to high values and plasma glucose levels declined. Both patients are currently insulin-independent, with UA values ranging from 10,000 to 200,000 U/24 hr. Both experimentally and clinically UA is an early predictor of pancreas allograft rejection. The institution of early treatment of rejection episodes in dogs, based on UA, significantly improved allograft survival. Urine amylase monitoring in pancreas transplant recipients could lead to an early treatment of rejection and improve graft survival.

Amylases↗
PubMed1987

Pancreas transplant results according to the technique of duct management: bladder versus enteric drainage.

Between July 1978 and February 1987, 177 pancreas transplants were performed. The 1-year patient and graft survival rates for the first 100 transplants up to October 1984 were 88% and 27%, respectively. Since November 1984, duct drainage has been used for 74 of 77 transplants, bladder (BD) in 36 and enteric (ED) in 38, with 1-year patient survival rates of 89% and 92%, respectively, and graft survival rates of 58% and 42%. The technical failure rate was similar in both groups (31%). Immunosuppression was with antilymphocyte globulin, cyclosporine, azathioprine, and prednisone. Most recipients were nonuremic, without kidney transplants, and 1-year graft survival rates were 69% for BD (n = 21) and 42% for ED (n = 29). The diagnosis of rejection was based on a decline in urine amylase activity in the BD and on an increase in plasma glucose alone in the ED group. For technically successful (TS) grafts, the number of rejection episodes reversed per number diagnosed was 23 of 26 (18 patients) in BD (88%) and six of 15 (14 patients) (40%) in ED (p less than 0.05). The advantage of BD with monitoring of urine amylase activity is seen in TS cases; 1-year cadaveric graft survival rates were 90% for BD (n = 23) versus 47% for ED (n = 15) (p = 0.05). In recipients of segmental transplants with ED from living-related donors, 1-year graft survival rates were 57% overall (n = 18) and 88% for TS cases (n = 12), which is identical to cadaveric BD cases. A disadvantage of BD was metabolic acidosis induced by chronic bicarbonate loss in the urine from the pancreas graft. Nevertheless, we conclude that BD is the preferred technique for pancreas transplants from cadaver donors because of the ability to monitor exocrine and endocrine function continuously, thus leading to early diagnosis and treatment of rejection episodes.

Adult↗
PubMed1986

Urinary amylase monitoring for early diagnosis of pancreas allograft rejection in dogs.

The diagnosis of pancreas allograft rejection is usually made on the basis of blood glucose concentration, a late indicator of rejection. We performed segmental pancreas transplants in totally pancreatectomized dogs with the exocrine secretions drained into the bladder (ductocystostomy). We directly measured exocrine pancreatic secretions (urinary amylase), in an attempt to find a sensitive indicator for early rejection. Five groups were studied: (I) autografts; (II) autografts immunosuppressed with cyclosporine (CsA), azathioprine and prednisone; (III) allografts without immunosuppression; (IV) allografts immunosuppressed with CsA alone; (V) allografts immunosuppressed with CsA, azathioprine, and prednisone. The control groups (I, II) maintained high urine amylase concentrations indefinitely (mean +/- SE of 125,544 +/- 36,931 u/liter). Rejection, as diagnosed by rise of serum glucose to greater than 150 mg/dl, occurred at a mean (+/- SE) of 9.0 +/- 0.2 days in nonimmunosuppressed recipients of Group III, at 9.3 +/- 0.7 days in cyclosporine-treated dogs of Group IV, and at 28.0 +/- 8.3 days after transplantation in dogs immunosuppressed with triple therapy of Group V. In all allograft recipients, urine amylase declined precipitously (less than 1000 u/liter) before the onset of hyperglycemia, by 1.3 +/- 0.2 days in Group III, 3.3 +/- 1.0 days in Group IV, and 9.4 +/- 2.8 days in Group V. In a further experiment, nine dogs with pancreas allografts received cyclosporine for prophylactic immunosuppression; further antirejection therapy with azathioprine and antilymphocyte globulin was given for 5 days beginning the first day that rejection was diagnosed. In five dogs (Group A) rejection was diagnosed when serum glucose rose to greater than 150 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)

Amylases↗
PubMed1985

Multiple hepatic adenomas after long-term therapy with testosterone enanthate. Review of the literature.

We report a case of multiple hepatic adenomas developed in a 32-year-old man with renal allograft after long-term therapy with testosterone enanthate. Histological assessment showed a benign hepatocellular adenoma, which has not regressed over a 6-month follow-up since androgen withdrawal. A review of primary hepatic tumors associated with androgenic-anabolic steroid therapy published in the English literature has been carried out, concentrating on the more relevant recent publications. No previous case of hepatic adenoma with possible relationship to the use of non-17-alpha alkylated compounds has been reported.

Adult↗