Plasma leptin is directly related to body adiposity in subjects with spinal cord injury

We addressed the relationship between plasma leptin and body mass index in 48 able-bodied male controls and 34 male subjects with spinal cord injury, as well as the association between plasma leptin with body fat by dual energy x-ray absorptiometry in those with spinal cord injury. In subjects with spinal cord injury, the effect of an oral glucose tolerance test and the relationship of the serum lipid profile with plasma leptin levels were determined. Body mass index was not significantly different between the spinal cord injury and control groups. Plasma leptin was significantly higher in the group with spinal cord injury than in the control group (12.7 +/- 1.7 vs. 7.6 +/- 0.9 ng/ml, p < 0.005). A linear relationship was found between plasma leptin and body mass index in both groups separately (spinal cord injury: r = 0.59, p < 0.0002; control: r = 0.67, p < 0.0001). In those with SCI, a polynomial relationship was evident between plasma leptin and percent fat (r = 0.82, p < 0.0001). After an oral glucose load, plasma insulin levels and serum glucose concentrations were not related to plasma leptin levels. Serum triglycerides were found to be weakly correlated with plasma leptin levels (r = 0.35, p < 0.05). The higher plasma leptin levels in the group with spinal cord injury compared with the control group was probably due to a relatively increased percentage of adiposity in those with spinal cord injury.     

Diethyl ether. 1963

Chlamydia psittaci is a significant cause of conjunctivitis in cats, but can be difficult to diagnose owing to the small number of organisms in conjunctival swabs. In the United Kingdom laboratory diagnosis is based on three techniques: isolation of the infectious organism, amplification of chlamydial DNA by the polymerase chain reaction (PCR) or the detection of anti-chlamydial antibodies by immunofluorescence assay. To determine the most sensitive method these techniques were compared in the field. The PCR based on previously published protocols was less sensitive than isolation, but by modifying the protocol its sensitivity was increased by a factor of 25 to 1250 and it was then more sensitive than isolation. The modified PCR detected chlamydia in samples containing non-infectious organisms. Serology was of limited use in predicting which cats shed C psittaci although seronegative cats were negative by PCR and isolation. The modified PCR was the most sensitive and robust method for confirming C psittaci infection in cases of conjunctivitis in pet cats.     

Correlation between the magnetic properties and the chemical shifts in x-ray absorption spectra of some transition metal compounds

Studies on the chemical shifts of the K x-ray absorption discontinuities of some transition metal compounds recently conducted in our laboratory have revealed that the ΔE vs q curves do not pass through the origin. For such systems one obtains an intercept on the ΔE axis, which seems to depend uponn _d , the number of unpairedd electrons. As is well-known the magnetic properties of the compounds of transition metal elements are governed by thed electrons. It is shown that the magnetic properties of the transition metal compounds may be correlated with x-ray absorption spectra.     

Comparison of Escherichia coli strains recovered from human cystitis and pyelonephritis infections in transurethrally challenged mice

Urinary tract infection, most frequently caused by Escherichia coli, is one of the most common bacterial infections in humans. A vast amount of literature regarding the mechanisms through which E. coli induces pyelonephritis has accumulated. Although cystitis accounts for 95% of visits to physicians for symptoms of urinary tract infections, few in vivo studies have investigated possible differences between E. coli recovered from patients with clinical symptoms of cystitis and that from patients with symptoms of pyelonephritis. Epidemiological studies indicate that cystitis-associated strains appear to differ from pyelonephritis-associated strains in elaboration of some putative virulence factors. With transurethrally challenged mice we studied possible differences using three each of the most virulent pyelonephritis and cystitis E. coli strains in our collection. The results indicate that cystitis strains colonize the bladder more rapidly than do pyelonephritis strains, while the rates of kidney colonization are similar. Cystitis strains colonize the bladder in higher numbers, induce more pronounced histologic changes in the bladder, and are more rapidly eliminated from the mouse urinary tract than pyelonephritis strains. These results provide evidence that cystitis strains differ from pyelonephritis strains in this model, that this model is useful for the study of the uropathogenicity of cystitis strains, and that it would be unwise to use pyelonephritis strains to study putative virulence factors important in the development of cystitis.     

L-ascorbyl-2-polyphosphate as a vitamin C source for segregated and conventionally weaned pigs

We conducted two experiments to evaluate the efficacy of a stable source of vitamin C for improving performance and iron status in early-weaned pigs. A preparation of L-ascorbyl-2-polyphosphate (Rovimix Stay-C 25, Roche Vitamins, Ames, IA and Bramus, NJ), which supplies 25% ascorbic acid activity in a stable form, served as the vitamin C source and was incorporated at dietary vitamin C levels of 0, 75, or 150 ppm. In Exp. 1, 72 pigs (14 +/- 2 d of age and 4.98 kg BW) were blocked based on initial BW and penned in groups of three (eight pens per treatment) in an off-site nursery for 42 d. Phase 1 lasted from d 0 to 14, Phase 2 from d 14 to 28, and Phase 3 from d 28 to 42 after weaning. Daily gain and gain:feed ratio (G/F) increased during Phase 1 (quadratic, P < .1 and P < .05, respectively), Phase 3 (linear, P < .1 and P < .01, respectively), and for the overall 42-d experiment (linear, P < .05 and P < .1, respectively) in response to increasing dietary vitamin C. At 14 d after weaning, plasma vitamin C increased (linear, P < .05) with increasing dietary vitamin C, but plasma iron, hemoglobin, and hematocrit were not influenced by dietary vitamin C. In Exp. 2, 120 pigs (20 +/- 3 d of age and 7.2 kg BW) were blocked based on initial BW and penned in groups of five (eight pens per treatment) in a conventional nursery system for 31 d. Phase 1 consisted of d 0 to 7, Phase 2 from d 7 to 17, and Phase 3 from d 17 to 31 after weaning. During the period from d 0 to 17 after weaning, ADG and G/F were improved (linear, P < .1) with increasing dietary vitamin C. At d 17 after weaning, plasma vitamin C and serum iron increased (linear, P < .05), but unbound iron-binding capacity and total iron-binding capacity decreased (linear, P < .05 and P < .1, respectively) with increasing dietary vitamin C. These results suggest that dietary vitamin C is needed during the first 42 d after weaning when pigs are weaned as early as 12 d of age and reared in an off-site nursery and during the first 17 d after weaning when pigs are weaned as early as 17 d of age and reared in a conventional nursery system. L-Ascorbyl-2-polyphosphate at a supplemental level of 75 ppm was adequate to meet the dietary vitamin C requirement of early-weaned pigs. Vitamin C supplementation with a stable product will improve performance in young pigs during the high-stress postweaning period and may be particularly beneficial to pigs weaned at a very early age.     

Hypertensive encephalopathy: recognition and management

Hypertensive encephalopathy is a dramatic syndrome characterized by severe elevation of blood pressure, headache, visual disturbances, altered mental status, and convulsions. Although the syndrome is uncommon, to recognize and treat it promptly is important or the condition may prove to be fatal. Hypertensive encephalopathy should be distinguished from other cerebral complications of severe hypertension by obtaining careful history and performing thorough physical examination. The only definitive criterion for the diagnosis of this syndrome is its prompt response to therapy. If the patient's condition does not improve with hypotensive therapy, the physician should immediately search for alternate diagnoses. Potent drugs are available for prompt reduction of blood pressure. There are few medical emergencies in which the objective response to therapy is so strikingly apparent as in hypertensive encephalopathy.     

Gas-liquid chromatographic headspace technique for determination of vinyl chloride in corn oil and three food-simulating solvents

A gas-liquid chromatographic headspace technique for the determination of vinyl chloride (VC) in corn oil, 50% ethanol, 3% acetic acid, and n-heptane is described. These food-simulating solvents and the corn oil are placed in septum-sealed bottles and heated to 90 degrees C, and aliquots of headspace vapor are injected into a gas-liquid chromatograph equipped with a flame ionization detector. VC may be quantitated at concentrations of 1 ppb or less. This technique was used to measure the migration of VC into corn oil and 50% ethanol from 2 unplasticized polyvinyl chloride sheets containing 0.28 and 0.44 ppm residual monomer.     

Studies on melt spinning. VIII. The effects of molecular structure and cooling conditions on the severity of draw resonance

The effects of molecular structure and cooling conditions on the severity of draw resonance was investigated by carrying out carefully controlled melt spinning experiments. For the study, two types of polymeric materials were used: one which exhibits viscoelastic behavior (high-density polyethylene, polypropylene, and polystyrene), and the other which exhibits almost Newtonian behavior [nylon-6 and poly(ethylene terephthalate)]. In order to investigate the effect of cooling on the severity of draw resonance, different methods of cooling the molten threadline were employed. In one set of experiments, isothermal chambers of various lengths (3, 6, and 12 in.) were attached to the spinnerette face, so that the molten threadline, upon exiting from the spinnerette, began to cool in the ambient air only after it had passed through the isothermal chamber. This method of cooling is called “delayed cooling,” providing both an isothermal region (inside the isothermal chamber) where only stretching occurs, and a nonisothermal region (outside the isothermal chamber) where both stretching and cooling occur simultaneously. In other experiments, the temperature profile of the molten threadline was controlled by adjusting the temperature of the heated chamber. This method of cooling provides a gradual drop of the threadline temperature, compared to the more sudden drop when spinning into a cold environment provided at the spinnerette exit. The severity of draw resonance was recorded on movie film, and the thread tension was measured with a low-force load cell transducer and recorded on a chart recorder. The temperature of the threadline along the spin direction was measured using a fiber optical probe attached to a Vanzetti Infrared Thermal Monitoring System (Model TM-1). It was found that the severity of draw resonance depended on the molecular structure and the way the molten threadline was cooled. Of particular interest is the observation that, for the viscoelastic materials investigated, cooling destabilized the molten threadline outside the isothermal chamber. This gave rise to more severe resonant behavior, at and above the critical draw-down ratio, in contradiction to the theoretical prediction by Fisher and Denn. It was observed, also, that the elasticity of the materials tended to destabilize the molten threadline (i.e., it increased the severity of draw resonance), again in contradiction to the theoretical prediction of Fisher and Denn. It is believed that morphological changes of polymers may play an important role in the occurrence of draw resonance when a melt threadline is stretched under cooling. Our study indicated that a good understanding of draw resonance of viscoelastic fluids requires more careful study than the classical hydrodynamic stability analysis reported by Fisher and Denn. They based their analysis on several convenient and yet unjustified assumptions, and solely on phenomenological considerations. We suggest that future theoretical analysis of draw resonance be carried out by considering a fluid model with a nonlinear memory function in order to properly account for the deformation history of the fluid, and the relaxation and cooling processes in the die swell region and the region below it.     

Clinical experience with technetium-99m stannous polyphosphate for myocardial imaging

Myocardial imaging with technetium-99m stannous polyphosphate was performed on 46 patients. Eleven patients had no cardiac disease, 22 had acute myocardial infarction, and 13 had stable arteriosclerotic heart disease. Distinct patterns of myocardial activity were noted: (1) the patients with no obvious cardiac disease showed no cardiac activity; (2) stable arteriosclerotic heart disease showed faint, ill-defined cardiac activity, primarily in the anterior or inferior aspect of the left ventricle; (3) acute myocardial infarction showed intense, focal, well-defined activity, with a shape that characterized the location of the infarct.