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C Mora

Publications and source records attributed to C Mora.

89 records · Page 5Linked to original sources
PubMed1976

Selection of extranuclear mutants of Neurospora crassa.

A procedure is described that produce primarily extranuclear mutants, of Neurospora carassa. An analysis of five mutants. [cni-3], [rsp-2], [rsp-3], E1RSP-4], IS PRESENTED. All five mutants segregate in an extranuclear manner. They can be assorted into two classes based on their respiratory properties: (1) those with cyanide-insensitive respiration (cni); (2) those with slow respiration (rsp). All of the mutants are female sterile. The respiratory trait can be placed in different nuclear backgrounds by heterokarytoic transfer. The abnormal respiratory traits are observed in mitochondria isloated from the mutants and it is likely that the mutations are in mitochondrial DNA.

Cell Nucleus↗
PubMedDate not supplied

Ultrastructural pathology of a Chilean case of tropical spastic paraparesis/human T-cell lymphotropic type I-associated myelopathy (TSP/HAM).

Human T-cell lymphotropic virus type I (HTLV-I), is the cause of endemic tropical spastic paraparesis (TSP) or HTLV-I-associated myelopathy (HAM). Because TSP/HAM is not a fatal disease, the neuropathology of this disease, albeit relatively well understood, is based on the examination of just a few incidental cases. Previously, we demonstrated peculiar lamellated structures, called "multilamellar bodies" (MLB). In this report, we present the ultrastructural neuropathology of a TSP/HAM case from Chile, with further detailed descriptions of MLB. It is tempting to suggest that MLB may represent specific ultrastructural markers of TSP/HAM. The pathology of the anterior and posterior horns was similar and was comprised of axonal degeneration, accompanied by extensive astrocytic gliosis. Lymphocytic infiltration, particularly observed as "cuffs" around blood vessels, was scattered among other cellular elements. Ultrastructurally, myelin sheaths were relatively well preserved, and some demyelinated but not remyelinated fibers were observed. Moreover, axons with abnormal accumulations of neurofilaments, suggestive of axonal degeneration, were detected. Several axons contained Hirano bodies. In many samples, glial processes replaced most of the remaining neuropil. In a few specimens of the anterior and posterior horns of the spinal cord, MLB were observed. These structures consisted of stacks of 30 to 40 electron-dense lamellae, which were interrupted by narrow electron-lucent spaces. All of the lamellae were immersed within an amorphous substance of intermediate density. Neurons of the dorsal root ganglia were basically normal except for increased lipofuscin accumulation. As in the spinal cord, myelinated axons were well preserved, but a few were demyelinated and surrounded by concentric arrays of Schwann cell membranes. Also, axons of the dorsal roots accumulated increased number of neurofilaments. Mast cells and Schwann cells were increased in number, the latter containing abundant pi granules and myelin fragments.

Astrocytes↗
PubMedDate not supplied

In-depth review effect of androgens on anemia and malnutrition in renal failure: implications for patients on peritoneal dialysis.

OBJECTIVE: To analyze the implications of the potential use of androgens in peritoneal dialysis patients, focusing on their effects on hematologic and nutritional parameters. This manuscript reviews the different compounds for clinical use, dosage schedules, adverse effects, and how therapy with androgens might be used to treat anemia and malnutrition in these dialysis patients. DATA SOURCES: Studies in the literature dealing with the effects of androgens on hematologic and nutritional parameters, and their role in uremic anemia and malnutrition. STUDY SELECTION: Studies in which uremic patients received androgens as therapy for anemia or malnutrition. DATA EXTRACTION: Data were abstracted from all of these studies. RESULTS: This review shows that androgens are anabolic substances that also have significant actions on erythropoiesis. A number of clinical studies in uremic patients have found that these compounds have beneficial effects on hematologic parameters and nutritional status, similarly to other therapies, such as recombinant human erythropoietin and recombinant human growth hormone, respectively. CONCLUSIONS: Androgens have been shown to have a beneficial effect on anemia due to renal disease and on nutritional status in uremic patients. Further studies need to be done with larger groups of patients. Objectives for additional research are suggested.

Androgens↗
PubMedDate not supplied

Serum magnesium concentration is an independent predictor of parathyroid hormone levels in peritoneal dialysis patients.

BACKGROUND: Parathyroid hormone (PTH) is a cardinal factor in the pathogenesis of bone disease in the dialysis population. The spectrum of renal osteodystrophy has been reported to have changed during the past years, and adynamic bone disease has emerged as the most common bone disorder in these patients. Continuous ambulatory peritoneal dialysis (CAPD) is considered a risk factor for the development of this condition, and furthermore, the adynamic bone lesion is associated with a state of relative hypoparathyroidism (hypo-PTH). Calcium, vitamin D, and phosphorus play a key role in the control of parathyroid gland function in uremic patients. However, magnesium may also be able to modulate PTH secretion in a way similar to calcium. OBJECTIVE: The aims of this study were (1) to analyze the serum Mg concentration in a large group of CAPD patients, (2) to study the relationship between serum Mg and PTH levels, and (3) to investigate whether this relationship is independent of other factors, such as calcium, phosphorus, and calcitriol, that regulate parathyroid function. PATIENTS AND METHODS: We studied 51 stable patients, aged 23-77 years, under maintenance CAPD for more than 6 months (range 8-48 months). Calcium carbonate was used as a phosphate binder in all patients, and 9 subjects also received aluminum hydroxide. No patient had been previously treated with vitamin D. Biochemical parameters were prospectively evaluated over 6 months, and the mean values were computed. RESULTS: The mean serum Mg was 1.08 +/- 0.19 mmol/L, and hypermagnesemia, defined as a Mg level higher than 1.01 mmol/L, was found in 30 patients (59%). Thirty-one subjects (60%) had an intact PTH (iPTH) level lower than 120 pg/mL and were diagnosed as having relative hypo-PTH. Except for the values of iPTH and alkaline phosphatase, the only difference between the two groups was the serum Mg concentration, which was significantly higher in patients with hypo-PTH (1.16 +/- 0.15 mmol/L vs 0.91 +/- 0.14 mmol/L; p< 0.001). Furthermore, iPTH levels were lower in patients with hypermagnesemia than in subjects with normal serum Mg (69 +/- 49 pg/mL vs 190 +/- 89 pg/mL, p < 0.001). There was a significant correlation between serum Mg and PTH levels (r= -0.70, p< 0.01). After controlling for the effect of other variables by partial correlation analysis, a significant positive association between P and PTH (r= 0.25, p < 0.05), and a negative relationship between Mg and PTH (r= -0.57, p < 0.001) were evident. A forward stepwise multiple regression analysis showed that only P and Mg predicted PTH values (multiple r = 0.59, p < 0.001). CONCLUSIONS: Hypermagnesemia and hypoparathyroidism are frequent in CAPD patients. There is a significant inverse relationship between serum Mg concentration and iPTH levels. Furthermore, this association is independent of the most important factors regulating parathyroid gland function (calcium, phosphorus, and calcitriol). These results suggest that hypermagnesemia may have a suppressive effect on PTH synthesis and/or secretion. Therefore, elevated serum Mg levels may play a role in the pathogenesis of adynamic bone disease.

Adult↗
PubMedDate not supplied

[Spinal anesthesia and morphine analgesia in prostatic surgery].

The authors compare the effects of either 0,5 or one milligram of intrathecally injected morphine on the post-operative course of 45 patients scheduled for transvesical prostatectomy. The patients were randomly assigned to three groups. Group A patients served as reference and were anesthetized by intrathecal injection of prilocaine 100 mg. Group B and C patients underwent the same anaesthetic procedure but prilocaine was injected simultaneously with either 0,5 (B) or one milligram (C) of morphine. Group A patients experienced postoperative pain for eighteen hours and requiring a mean subcutaneous dose of 20 mg of morphine. B and C patients had a satisfactory degree of analgesia. Nevertheless, there was a statistically significant difference of analgesia scores between groups C and B. The group C patients remained free of respiratory impairment. One mg of intrathecal morphine seems optimal for analgesia after prostatectomy.

Anesthesia, Spinal↗
PubMedDate not supplied

[Pancreatic pseudocyst. A review of 10 years].

In the hope of finding those patients whose pancreas pseudocyst resolution were spontaneous, we undertook a retrospective review of such cases admitted at the Hospital Central de San Cristobal y Hospital Patrocinio Peñuela Ruiz (from IVSS), with the diagnosis of acute pancreatitis. From 619 patients with pancreatitis, 40 developed a pseudocyst (5.78%). The most frequent ethiology was biliary disease (47.5%) and abdominal pain in 87.5%, the most common symptom. Abdominal ultrasonography was the best diagnostic aid. Spontaneous resolution occur in 24 cases (60%) in juntion with the normalization of seric and urinary amylases values, the size of the cyst in these patients was less than 5 cms. Sixteen patients needed surgery, in 8 of them the seric amylase value remained high and in 3 cases this value was normal but with a cyst size more than five cms. Internal drainage in 11, external in 4 and surgical resection in one. There was no deaths in this review.

Acute Disease↗