The antihemorrhagic factor of the Mexican ground squirrel, (Spermophilus mexicanus).

The Mexican ground squirrel (Spermophilus mexicanus) has a natural resistance to western diamondback rattlesnake venom (Crotalus atrox). The LD50 for the Mexican ground squirrel is 53 mg/kg body weight, which is 13 times higher than that of BALB/c mice. An antihemorrhagic factor from serum of the Mexican ground squirrel was isolated using Sephadex G-200 gel filtration, ion exchange A-50, G-75 gel filtration and HPLC DEAE 5PW ion exchange chromatography. The purified factor neutralized proteolytic and hemorrhagic activity of crude C. atrox venom. The results of this research suggest that the antihemorrhagic factor in the serum of the Mexican ground squirrel is not an antibody and neutralizes hemorrhagic activity of C. atrox venom.

High blood lead levels in ceramic folk art workers in Michoacan, Mexico.

Ceramic folk art workers are at risk for developing lead intoxication. These workers live in small settlements, which often lack sanitation services, and these individuals work with ceramics in their homes. The study population comprised individuals of all ages from three rural communities in central Michoacan (Tzintzuntzan, Tzintzunzita, and Colonia Lazaro Cardenas). A survey questionnaire, which was provided to each individual, included questions about household characteristics, presence of a clay oven in the home, and use of lead oxide ("greta") and other hazardous products. Venous blood samples were obtained from the workers. We found lead exposure to be reduced if the home floor was covered and if the house had been painted < or =1 y prior to study. Blood lead levels exceeded the maximum level permitted, but the levels were lower than those found in the 1970s, during which time study techniques for analyzing samples differed from those used in the present study. In addition, activity patterns of the populations differed during the two studies.

Tratamiento con ciclosporina de la artritis reumatoídea refractaria / Treatment of refractory rheumatoid arthritis with cyclosporine

Cyclosporine may be useful in the treatment of rheumatoid arthritis refractory to other immunosupressive agents, in doses of less than 10 mg/kg/day to minimize its nephrotoxic potential, that is enhanced with prolonged use of concomitant administration of antiinflammatory drugs. We report 15 patients aged 50 ñ 12 years with erosive rheumatoid arthritis lasting 5 ñ 4 yeras and refractory to other immunosupressive agents. They were studied during one year and received cyclosporine in initial doses of 2.5 mg/kg/day that were increased to 5 mg/kg/day, assessing clinical response, blood pressure and serum creatinine. Nine patients, that received a maximal dose of 3.4 ñ 0.7 mg/kg/day during 7 ñ 4 months, improved; a 30 percent increase in creatinine was observed in 3, blood pressure raised in six and 2 bad hepatic toxicity. in the 6 patients that did not improve, the mean treatment lapse was 4 ñ 3 months and the maximal dose achieved was 2.7 mg/kg/day; creatinine increased in one and blood pressure increased in 4. It is concluded that although the clinical response to cyclosporine was good, only 4 patients completed one year of treatment, due to the frequent secondary effects of the drug

Hypophysectomy eliminates and growth hormone (GH) maintains the midpregnancy elevation in GH receptor and serum binding protein in the mouse.

[125I]Iodomouse GH [( 125I]iodo-mGH) binding to samples of serum and hepatic microsomal membranes was measured in hypophysectomized pregnant, sham-operated pregnant, intact pregnant, and intact adult virgin mice. Surgeries were carried out on day 11 of pregnancy, and the animals were killed on day 14. The binding of mGH to both serum and hepatic microsomal membranes of intact virgin mice was much lower than to those of intact pregnant mice. In hypophysectomized mice, the mGH-binding capacity of both serum and hepatic microsomes decreased to values similar to those of nonpregnant mice. No significant differences were observed between intact and sham-operated pregnant animals in the maternal serum mGH concentration, the serum GH-binding protein concentration, or the hepatic GH receptor concentration. GH receptor and binding protein-encoding mRNAs were also higher in intact and sham-operated pregnant mice than in virgin and hypophysectomized mice. Hypophysectomized mice were treated with 200 micrograms/day bovine GH, administered by osmotic minipump; after 3 days of treatment, a significant elevation of hepatic GH receptor and serum GH-binding protein levels was observed. These results demonstrate an up-regulation of hepatic GH receptors and serum GH-binding protein by GH during pregnancy in the mouse.

The effects of graded administration of positive end expiratory pressure on the fluid filtration rate in isolated rabbit lungs, using normal lungs, hydrostatic oedema lungs and oleic acid induced oedema.

The influence of positive end expiratory pressure (PEEP) on the fluid filtration rate (FFR) in the pulmonary circulation has been the subject of considerable investigation but data are conflicting. We studied twenty-nine isolated rabbit lung preparations, FFR was sensed by a force transducer. Autologous blood was used to prime the perfusion circuit. Hydrostatic oedema was achieved by increasing the left atrial pressure to 16 mmHg. In order to bring about increased membrane permeability oleic acid was injected through the pulmonary artery. Increasing and decreasing levels of PEEP at 0, 5, 10 and 15 cm H2O were each used for ten minutes in each of three experimental models. The FFR, pH, mean pulmonary arterial pressure (MPAP), mean left atrial pressure (MLAP), PaO2, PaCO2 and oncotic pressure were measured in each experiment. There was a significant correlation between PEEP and FFR (+0.94) in non-oedema lungs. With no PEEP the FFR was 0 g/min and with 15 cm of PEEP it increased to 0.07 g/min, on removing the PEEP the FFR returned to 0 g/min. In the hydrostatic lung oedema model the correlation was also significant but negative (r = -0.94). With no PEEP the FFR was 0.33 g/min, with PEEP of 15 cm H2O it decreased to 0.08 g/min. No correlation between PEEP and FFR was found in the oleic acid preparation. In the normal lung PEEP increases capillary hydrostatic pressure and total lung vascular area and decreases interstitial pressure. It is by these mechanisms that PEEP causes an increase in FFR. In the hydrostatic oedema model PEEP decreases FFR by increasing the interstitial pressure and by decreasing the total lung vascular area. In the oleic acid preparation the coefficient of filtration is so large that small changes in pressure or vascular area do not modify the FFR. We suggest that PEEP may be beneficial by decreasing FFR in hydrostatic lung oedema, but it may increase the FFR in the normal lung, while having no effect in oleic acid lung injury.

Triacylglycerol kinetics in endotoxic rats with suppressed lipoprotein lipase activity.

Hypertriglyceridemia observed in animals after bacterial endotoxin administration and some forms of sepsis can result from increased hepatic triacylglycerol (TG) output or decreased TG clearance by extrahepatic tissues. To differentiate between these two possibilities, TG and free fatty acid (FFA) kinetics were determined in control and endotoxin-injected (0.1-0.5 mg/100 g) rats 18 h after treatment. Plasma TG and FFA kinetics were assessed by a constant intravenous infusion with [9,10-3H]palmitate-labeled very low-density lipoprotein and [1-14C]palmitate bound to albumin, respectively. In addition, lipoprotein lipase (LPL) activity was determined in heart, skeletal muscle, and adipose tissue as well as in postheparin plasma of functionally hepatectomized, adrenalectomized, and gonadectomized rats. Plasma FFA acid concentrations were slightly increased in endotoxin-treated rats but their turnover did not differ from control. Endotoxin-treated rats had a threefold increase in plasma TG concentrations and decreased heart, skeletal muscle, and post-heparin plasma LPL activity. Plasma TG turnover was decreased, indicating that hypertriglyceridemia was not due to an increased TG output by the liver. Instead, the endotoxin-induced increase in plasma TG concentration was a consequence of the 80% reduction in TG metabolic clearance rate. Thus, suppression of LPL activity in endotoxic animals impairs TG clearance resulting in hypertriglyceridemia. Furthermore, endotoxin administration reduced the delivery of TG-FFA to extrahepatic tissues because hepatic synthesis and secretion of TG from plasma FFA was decreased and LPL activity was suppressed.

Periprosthetic cyst formation: an unusual complication of polytetrafluorethylene prosthesis implantation.

Two cases of periprosthetic cyst formation after polytetrafluorethylene (PTFE) graft implantation are reported. This complication may have resulted from imperfect incorporation of the graft material by the surrounding tissues. The cause of such defective incorporation, and hence the means of prevention, remains unknown.

[Intracranial pressure. Direct measurement in the cisterna magna]. / Presión intracraneana. Medida directa en la gran cisterna.

The intracranial cisternal or supraoccipital punction in the sitting position, was undertaken in 523 cases, of which 329 presented increased intracranial pressure. The procedure must be done by experts, and was well tolerated. There were no cases of death, arterial hemorrhages or medullary lesions. In 451 cases CSF pressure was measured and CSF was extracted for laboratory examination. Pneumoencephalograms were undertaken with this method in 335 patients. The intracranial cisternal pressure in the sitting position is greater than the suboccipital or cervical cisternal pressure by 1.5 to 3cm H2O. Its value is practically equal to the pressure in the posterior fossa, and when the medial ventricular system is patent, is similar to the pressure in the supratentorial fossas. The intracranial cisternal punction has less risks than the suboccipital punction and can be undertaken in patients with rised intracranial pressure In 62 cases the tap was negative; this led to the diagnosis of amygdaline herniation and the procedure was interrupted without mishap. The authors consider that, in the future, the connection of the cisternal catheter with a transducer, will permit the continuous monitoring of the intracranial cisternal pressure.