Automatic analysis of immunocytochemically stained tissue samples.

An automatic colour image segmentation and cell counting software system has been developed for immunocytochemical analysis of stained tissue samples. The system was designed to count the total number of positive and negative cells in tissue samples treated with cytokine DNA probes from pigs naturally parasitised with Taenia solium metacestodes, using in situ hybridisation. A reaction index was calculated as the ratio of the number of cells with a positive reaction to the total number of cells (positives plus negatives) for each of five different probes. The objectives of automatic counting were to improve the reproducibility of the analysis and reduce the processing time of large image batches. A fast KNN classifier was used for colour segmentation. Watershed segmentation combined with edge detection was used to isolate individual cells that were then automatically labelled, using the results of the corresponding colour segmented image. Validation was performed on 122 non-training digital images with a total of 1069 positive cells and 1459 negative cells, with the following results: a mean true positive rate of 90.2% for positive cells and a mean true positive rate of 85.4% for negative cells. The corresponding mean false positive rates were 9.6% and 6.6%. The mean reaction index error of the automatic analysis was 5.35%. The processing of each digital image took 10 s on a Pentium IV PC.

[Clinical and genetic studies of a family from Peru affected by spinocerebellar ataxia type 7]. / Investigación clínica y genética de una familia peruana afectada por ataxia espinocerebelosa tipo 7.

INTRODUCTION: Recently the clinical and genetic investigation of cerebellar diseases has experienced an extraordinary advance due to localization of the disorders in different chromosomal loci. This type of investigation has been done in Peru in the last decade, studying a Peruvian family from the Huarochiri province. PATIENTS AND METHODS: A Peruvian family of 65 individuals in five generations, affected by several neurological disturbances associated with ataxia, were studied by clinical, neurological, ophthalmological, neuroradiological and genetic methods. The genetic study was done in the neurogenetics laboratory of the University of Utah (Salt Lake City, United States). RESULTS: The patients showed equilibrium disturbances, gait difficulties, ophthalmoplegia, corticospinal signs, cognitive deficiencies, visual weakness, maculopathy, retinal degeneration, optic nerve atrophy and atrophy of the cerebellum, brain stem and cerebral hemispheres. The DNA in 30 individuals showed, in the neurologically affected, repeated expansion of CAG triplets in the short arm of chromosome 3p. CONCLUSIONS: The findings in this family suggests that they suffer from spinocerebellar ataxia type 7. This could be the first description of the disease in Latin-America.

Analysis of the dynamic mutation in the SCA7 gene shows marked parental effects on CAG repeat transmission.

The gene for spinocerebellar ataxia 7 (SCA7) includes a transcribed, translated CAG tract that is expanded in SCA7 patients. We have determined expansions in 73 individuals from 17 SCA7 kindreds and compared them with repeat lengths of 180 unaffected individuals. Subjects with abnormal expansions comprise 59 clinically affected individuals and 14 at-risk currently unaffected individuals predicted to carry the mutation by haplotype analysis. For expanded alleles, CAG repeat length correlates with disease progression and severity and correlates inversely with age of onset. Increased repeat lengths are seen in generational transmission of the disease allele, consistent with the pattern of clinical anticipation seen in these kindreds. Repeat lengths in expanded alleles show somatic mosaicism in leukocyte DNA, suggesting that these alleles are unstable within individuals as well as between generations. Although dynamic repeat expansions from paternal transmissions are greater than those from maternal transmissions, maternal transmission of disease is more common, suggesting germline or embryonic effects of the repeat expansion.

Ataxia cerebelosa autosómica dominante con prolapso de la válvula mitral / Autosomic dominant cerebellar ataxia with prolapse of the mitral valve

Reportamos una familia de 69 personas cuyos miembros nacieron en una ciudad ubicada a 2,700 metros sobre el nivel del mar, 20 de los cuales fueron afectados con ataxia cerebelosa progresiva autosómica dominante. Las edades de los pacientes estaban entre 16 y 69 años. En todos ellos se comprobó prolapso de la válvula mitral. La ataxia se asoció con piramidalismo, disminución de la agudeza visual por alteraciones del pigmento retiniano, degeneración pigmentaria de la mácula, así como palidez y atrofia del nevio óptico. El estudio con tomografía axial computarizada del cerebro demostró atrofia del cerebelo, del tronco cerebral y de los hemisferios cerebrales. Hubo diversos grados de alteraciones en la motilidad conjugada de los ojos. Las pruebas neuropsicológicas para determinar el nivel de inteligencia, en doce pacientes, demostraron deficiencia mental en todos ellos.

General surgical procedures in renal allograft recipients.

Since elective and emergent nontransplant-related surgical procedures are frequently necessary in renal allograft recipients, it becomes essential to determine the incidence and outcome of these operations in this population. For this reason, a retrospective analysis of 273 consecutive renal transplants performed in 254 patients between January 1978 and November 1985 was accomplished. During this interval, 139 patients underwent 162 nontransplant-related surgical procedures. In the 44 patients who underwent 55 emergent or semiemergent procedures, 8 patients (18 percent) died in the postoperative period. All deaths occurred in patients who underwent major abdominal or thoracic procedures for perforated viscera, gastrointestinal bleeding, or empyema and lung abscess, and all deaths were secondary to sepsis and multiple organ failure. In the survivors of emergent procedures, the mean preoperative and discharge serum creatinine levels were 2.87 mg/dl and 2.82 mg/dl, respectively. In the 95 patients who underwent 107 elective procedures, most of which were performed under general anesthesia, the operative mortality was 4.2 percent. In patients with stable renal allograft function at the time of operation, mean serum creatinine levels preoperatively and at the time of discharge were not significantly different (1.74 mg/dl versus 1.64 mg/dl). In conclusion, emergent operative procedures for intraabdominal or thoracic catastrophes are associated with a high mortality rate in renal allograft recipients. On the other hand, elective surgical procedures can be undertaken with an acceptable mortality rate and no adverse affects on graft function. Of utmost importance in these patients is the close monitoring of the immunosuppressive regimen and the early detection and treatment of potential septic complications.

In search of an in vitro index of viability during pancreatic preservation.

To determine an index of viability during pancreatic preservation, 15 dogs underwent segmental pancreatic autografting after 24 hr of pulsatile perfusion. These animals were divided into Group A (6) and Group B (9) on the basis of post-transplant normoglycemia or hyperglycemia. In each experiment, sequential perfusate amylase and arterial and venous blood gases were analyzed during preservation. In addition, sequential pancreatic tissue slices were obtained to determine in vitro insulin release. A comparison of perfusion parameters demonstrated no significant differences in pancreas weight (41 +/- 2.9 vs 38.3 +/- 1.5 mg), perfusate flow (0.24 +/- 0.2 vs 0.20 +/- 0.06 ml/min/g), diastolic (24.3 +/- 2.3 vs 26.9 +/- 1.6 mm Hg) or mean pressure (27.4 +/- 1.9 vs 30.1 +/- 1.5 mm Hg). Perfusate amylase levels (u/100 ml) and percentage change from baseline are as follows: (Table: see text). Perfusate amylase was significantly greater at 21 hr in Group A (P less than 0.005). In addition, a significantly greater rate of amylase release was evident in Group A at 1 hr (P less than 0.02), 3 hr (P less than 0.02), and 21 hr (P less than 0.01). Group B pancreata demonstrated significantly increased oxygen extraction at 1 hr (A-V O2 difference: Group A = -33, Group B = -68; P less than 0.05). In vitro insulin release of tissue slices obtained pre-harvest, post-flush, post-preservation, and 15 min post-transplantation was not significantly different in the two groups. In conclusion, sequential perfusate amylase and blood gas determinations may be useful in predicting pancreatic transplant function.

An in situ evaluation of distal splenic arteriovenous fistula on pancreas function in an isolated pancreas segment.

To determine the effects of a distal splenic arteriovenous fistula on endocrine function and pancreatic blood flow, 25 dogs underwent proximal pancreatectomy with the pancreatic tail left in situ and free intraperitoneal drainage of the pancreatic duct. Group A served as controls. In groups B through E, ligation of all nonpancreatic splenic vessels was accomplished. In group B, no further manipulations were performed. In group C, an arteriovenous fistula was created. Groups D and E were identical to groups B and C, respectively, except for the induction of bile pancreatitis. During intravenous glucose tolerance testing, the mean (+/- SEM) basal-to-peak insulin difference was 10.1 +/- 3.5 microU/mL in group A, 16.3 +/- 3.6 microU/mL in group B, 14.8 +/- 5.1 microU/mL in group C, 16.4 +/- 3.1 microU/mL in group D, and 13.0 +/- 4.4 microU/mL in group E. Corresponding mean (+/- SEM) glucose clearance values were as follows: -0.907% +/- 0.24%/min, -0.867% +/- 0.14%/min, -1.056% +/- 0.21%/min, -1.365% +/- 0.26%/min, and -0.887% +/- 0.20%/min. These values were not significantly different. Ligation of all splenic arterial and venous branches resulted in a 64.8% to 78.3% reduction in splenic artery blood flow that was restored to 60.9% to 84.9% of basal flow by an arteriovenous fistula (groups C and E). In conclusion, the creation of a splenic arteriovenous fistula was not beneficial in this model and other factors (rejection or technical) should be considered in vascular thrombosis following segmental pancreatic transplantation.

Selective posttransplantation bilateral native nephrectomy. Indications and results.

Twenty-five patients underwent bilateral native nephrectomy one to 68 months (mean, 15.6 months) following renal transplantation. The indications were erythrocytosis in two patients, recurrent urinary tract infection in three, medically uncontrolled hypertension in 18, and hypertension and urinary tract infection in two. One patient died two months after the nephrectomy, and one allograft was lost because of acute tubular necrosis. Both patients with erythrocytosis had prompt return of the hematocrit level and RBC mass to normal. Native nephrectomy eradicated the infection in each of the five patients with recurrent urinary tract infections. Results of nephrectomy for hypertension were classified as excellent in six patients, good in nine, and poor in four. Native renal-vein renin ratios of patients with excellent or good responses were not statistically different when compared with those of poor responders.

Etiology and management of bovine graft aneurysms.

From April 1975 to September 1980, 16 symptomatic bovine graft aneurysms were identified in 200 grafts used for long-term hemodialysis. Aneurysms occurred in five (3.6%) straight forearm grafts, two (33%) reversed forearm grafts, two (33%) straight thigh grafts, and seven (18.9%) upper arm grafts. Mean blood pressures were similar in the aneurysm and non-aneurysm groups (142/81 vs 153/83 mm Hg). At operation, the aneurysms were determined to be true in three patients and false in 13. Five patients were treated by graft ligation and aneurysm excision and 11 by aneurysm excision and graft revision, with additional graft survivals of one to 25 months. In conclusion, bovine graft aneurysms are usually false and are more frequent in proximal grafts. In the absence of infection, resection is indicated and will result in considerable prolongation of graft survival.