Food restriction-induced transformations in cardiac functional and biochemical properties in rats

The primary objective of this study was to ascertain if various degrees of marked chronic food restriction (FR) as well as the combination of FR and exercise training of moderate intensity induce changes in the functional properties of the heart that are consistent with previously reported findings indicative of downregulation of high-adenosinetriphosphatase V1 isomyosin expression. Adult female rodents were randomly assigned to one of four experimental groups: 1) free eating, 2) 50% food restricted, 3) 75% food restricted, or 4) 50% food restricted plus treadmill trained. Results show that FR induced significant depression in the functional properties (heart rate, left ventricular pressure, rate of pressure development, and double product) of the heart in all FR groups and that this depression in functional capacity corresponded to the degree of FR. These functional changes were accompanied by significant downregulation of the alpha- and upregulation of the beta-myosin heavy chain gene expressions, as studied at both the mRNA and protein levels. The exercise training induced further alterations in cardiac function; however, these alterations occurred independently of any shifts in isomyosin composition. These results suggest that although severe FR is a potent stimulus to transform both the biochemical and functional properties of the rodent heart, the underlying mechanism(s) concerning these adaptations remains unresolved.

Tuberculous peritonitis: an overlooked diagnosis

Contrary to widespread belief, abdominal tuberculosis is not rare, nor is it confined to the poor or patients with active pulmonary tuberculosis. The disease must be considered in the differential diagnosis of abdominal pain.

Control of myosin heavy chain expression: interaction of hypothyroidism and hindlimb suspension

The aim of this study was to contrast competing influences, hypothyroidism and hindlimb suspension, on myosin heavy chain (MHC) expression studied at the protein level and mRNA level. Female Sprague-Dawley rats were assigned to either normal control (NC), normal suspended (NS), or hypothyroid (thyroidectomized) control (TC) and suspended (TS) groups. NS and TS animals were suspended for 14 days following which myofibrils and total RNA were purified from the hindlimb muscles. In the soleus and vastus intermedius (VI), there was an increase in type I MHC and a decrease in type IIa MHC in both the TC and TS groups and a decrease in type I and increase in type IIa MHC in the NS group. At the mRNA level, similar shifts were observed with the exception that 1) the increased type IIa MHC seen in the soleus and VI of the NS animals was not accompanied by an increase in IIa mRNA and 2) type IIb mRNA was increased in the NS soleus without concomitant changes in IIb protein levels. These data suggest the following: 1) a hypothyroid state predominates over mechanical unweighting factors in the control of MHC distribution in slow muscles; and 2) translational or posttranslational factors may be important in the regulation of type IIa and IIb MHC expression during hindlimb suspension.

Effect of increased carbohydrate utilization potential on cardiac isomyosin in thyroidectomized rats

Previous studies have shown that dietary carbohydrate (CHO) can impact on cardiac isomyosin expression in hormonally deficient animals. The primary objective of this study was to determine whether a high-CHO diet alters cardiac isomyosin expression in severe thyroid-deficient rats. Also the effects of targeting the heart with episodes of biasing cardiac metabolism toward CHO were studied. Female Sprague-Dawley rats were assigned to one of two major groups: 1) normal control and 2) thyroidectomized (TX) propylthiouracil treated. The TX rats were allocated into four experimental subgroups as follows: 1) mixed diet; 2) high-CHO diet; 3) high-CHO diet and treated with oxfenicine, a fatty acid oxidation inhibitor; and 4) high-CHO diet, treated with oxfenicine, and trained. Results show that, at the end of 12 wk of thyroidectomy, there was a marked shift in cardiac isomyosin distribution to predominance of the V3 isoform. However, 6 wk of experimental manipulation failed to redirect cardiac isomyosin expression in TX rats. It is concluded that increased CHO utilization does not influence cardiac isoenzyme expression in markedly hypothyroid female rats. Dietary effects of CHO on cardiac isomyosin require some critical level of thyroid hormone for mediating the response.

Effects of low carbohydrate provision on isomyosin expression in the isoproterenol stressed rat heart

While previous findings suggest that increased carbohydrate (CHO) provision and/or utilization can be involved in the up regulation of V1 cardiac isomyosin expression in both the insulin deficient and the semi-starved rat, little is known about the role of CHO provision and/or utilization in regulating isomyosin expression in normal animals. This study was undertaken to ascertain whether a limited carbohydrate provision combined with repeated episodes of an increased cardiac energy demand can induce a down regulation of the V1 cardiac myosin inoenzyme in normal, young adult rats, i.e., a response similar to that seen in insulin deficient/food restricted rats. Animals were assigned to one of three major groups according to diet and/or drug treatment: (1) a mixed-diet control group; (2) a low-carbohydrate (LC)/high-fat-diet group; and (3) a low-carbohydrate-diet group treated with 3-mercaptopicolinic acid (MPA), an inhibitor of gluconeogenesis. In each of the above groups, subgroups of animals were metabolically challenged with daily isoproterenol injections (0.2 mg/kg/day) sufficient to markedly elevate cardiac work for at least 3 h. Four weeks of treatment reduced myofibrillar calcium activated ATPase activity by 17% (P less than 0.05) in the LC-diet-fed group treated with both isoproterenol and MPA. No change in myofibril ATPase was observed in any of the other experimental groups relative to the mixed diet control group. Isomyosin profile was not changed in any of the experimental groups. Tissue glycogen and plasma glucose and free fatty acid analyses provided indirect evidence of an increased utilization of fat for energy provision, especially in the low-carbohydrate-diet groups treated with MPA.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary effects on cardiac metabolic properties in rodents

Previous studies have shown that dietary provision of carbohydrate can alter cardiac isomyosin distribution in hormonally deficient rats. The main objective of this study was to determine if varying the heart's potential to utilize carbohydrate for energy provision can influence the cardiac isomyosin expression in normal weanling rats. Animals were assigned to one of five groups according to dietary and/or metabolic treatment: (1) mixed-control--(M); (2) high carbohydrate--(H); (3) low carbohydrate--(L); (4) mixed-diet supplemented with oxfenicine, a cardiospecific fatty acid oxidation inhibitor--(MO); and (5) high carbohydrate diet supplemented with oxfenicine--(HO). The results show that 4 weeks of dietary manipulations aimed to either increase or decrease carbohydrate supply to the heart, failed to induce any alterations in either cardiac myosin ATPase activity or isoenzyme pattern. However, extremes in carbohydrate provision altered the metabolic properties of both heart and skeletal muscle. A low carbohydrate diet increased 3-hydroxyacyl CoA dehydrogenase (P less than 0.05) and citrate synthase activities (P less than 0.05) and decreased glycogen content in both heart and soleus muscle; whereas, a high carbohydrate diet, in conjunction with oxfenicine, tended to increase hexokinase activity in these same tissues. These alterations provide indirect evidence that the contributions of both fat and carbohydrate to the energy balance of the heart and skeletal muscle were altered by the imposed dietary interventions. Collectively, these results suggest that although the substrate utilization patterns of the normal weanling heart can be modified via dietary manipulation, such shifts do not exert any regulatory influence on cardiac isomyosin expression.

Apparent influence of metabolism on cardiac isomyosin profile of food-restricted rats

In addition to thyroid hormone, carbohydrate oxidation appears to influence the relative distribution of rodent cardiac isomyosin (V1, V2, V3), especially in diabetic, thyroid-deficient, and food-restricted animals. To determine whether metabolic variations within the myocardium itself contribute to cardiac isomyosin distribution, food-restricted rats (predominantly V3) were treated with oxfenicine, a cardiospecific inhibitor of fatty acid metabolism. Animals received a mixed diet (50% carbohydrates) ad libitum (FE-M) or in restricted quantities (45% of FE-M; FR-M). Additional food-restricted animals received oxfenicine (75 mg/kg, twice daily) and either a mixed diet (FR-M-OXF) or a high-carbohydrate diet (75% carbohydrates, FR-HC-OXF). After 3 wk, hemodynamic and metabolic measurements were taken, serum 3,5,3'-triiodothyronine (T3) levels were measured, and cardiac citrate synthase (CS) activity and isomyosin distribution (percent V1, V2, V3) was determined. Relative to the FE-M group, thyroid status (CS, T3) was reduced only in the FR-M-OXF and the FR-HC-OXF groups (P less than 0.05). Oxfenicine treatment of food-restricted animals partially preserved the isomyosin profile of the FE-M group (P less than 0.05), suggesting that, within the context of food restriction, cardiac metabolism can influence cardiac isomyosin distribution independently of thyroid status.

Differential effects of carbohydrate intake on cardiac myosin isoform expression in normal weanling and adult rats

Dietary manipulations involving high carbohydrate feeding increase V1 cardiac myosin isoform expression in hormonally deficient rats. The purpose of this study was to determine if extremes in dietary carbohydrate availability could alter cardiac myosin isoform patterns in normal weanling and adult rats. Three and six weeks of dietary manipulations (either high or low carbohydrate diets) failed to change calcium-activated myofibril ATPase activity, calcium regulated myofibril ATPase activity, or the myosin isoform distribution in the adult. In contrast, a four week, high carbohydrate diet reduced calcium activated myosin ATPase activity by 33%, calcium regulated myofibril ATPase activity by 10%, and V1 isoform expression by 66% in weanling rats. Although the low carbohydrate diet caused no change in the myosin ATPase properties, it decreased V1 isoform expression by 17%. These results show that carbohydrate availability can alter cardiac myosin isoform expression in normal rats, but only at weanling age. The reason for this age-related contrast in response to dietary manipulations is unknown at this stage. The dietary manipulations may have acted directly on the heart by creating a state of malnutrition, or indirectly, by altering some developmental process which links maturation of the sympathetic nervous system with myosin isoform expression.

Spinal cord compression in neuroblastoma

Twelve of 80 patients suffering from neuroblastoma who were treated during a 21-year period had intraspinal involvement. Mediastinal tumors have a greater tendency to extend to the spinal canal; however, distant spread of the tumor is rare in patients presenting with intraspinal extension. Patients with intraspinal extension also survive longer than those without. Other factors affecting survival are age, stage of disease, duration of neurological symptoms, degree of histologic differentiation, and mode of therapy. In the absence of osseous metastasis, total excision of the primary lesion and its intraspinal components is usually followed by a favorable outcome; residual neurological deficits among survivors, however, are relatively common.

[Isodense intracranial hematomas: study of 5 cases]

The authors report 5 cases of isodense intracranial hematomas identified by computerized tomography and confirmed by angiography and surgical procedures. Radiological aspects are discussed and tomographic signals are emphasized.

[Meningioma of the posterior fossa with extracranial expansion in a child: report of a case]

A case of posterior fossa meningeoma with extracranial projection in a three years old female child is reported. The rarity of the process, its localization and the age group committed are emphasized. The radiological findings first suggesting an aneurismatic bone cyst like are commented. The surgical treatment with a posterior fossa approach and good results observed as well as the rarity of this pathology justify the report.

[Ectopic meningioma of the calvarium: report of a case]

A case of calvarial meningeoma in a 42 year old female is reported. Arising from the inner table of the skull, it projected a extracranial mass without neurological simptomatology. The surgical procedure give good results. Some aspects of the literature and radiologics finds are commented. The infrequency of this pathology is resulted.

[Intraventricular meningioma. Report of a case]

A case of meningeoma located at the right lateral ventricle is reported. The tumor was successfully removed by surgery. The authors justified this report by the infrequency of the pathology. Some aspects of the literature are commented.