A sexually dimorphic hypothalamic response to chronic high-fat diet consumption.

In this review, we discuss the observations that, following chronic high-fat diet (HFD) exposure, male mice have higher levels of saturated fatty acids (FAs) and total sphingolipids, whereas lower amounts of polyunsaturated FAs in the central nervous system (CNS) than females. Furthermore, males, when compared with female mice, have higher levels of inflammatory markers in the hypothalamus following exposure to HFD. The increase in markers of inflammation in male mice is possibly due to the reductions in proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) and estrogen receptor alpha (ERα), which is not recapitulated in female mice. Consistently, hypothalamic inflammation is induced both in male and female ERα total-body knockout mice when exposed to a HFD, thus confirming the key role of ERα in the regulation of HFD-induced hypothalamic inflammation. Finally, the HFD-induced depletion of hypothalamic ERα is associated with dysregulation in metabolic homeostasis, as evidenced by reductions in glucose tolerance and decrements in myocardial function.

Effect of the tropical forage calliandra on microbial protein synthesis and ecology in the rumen.

AIMS: To determine the effect of condensed tannins in Calliandra calothyrsus (calliandra) on rumen microbial function. METHODS AND RESULTS: Microbial populations, ruminal protein synthesis and fermentation end-products were measured in sheep fed roughage hay supplemented with calliandra (30%), with and without inclusions of polyethylene glycol (PEG) to counteract the effect of tannin. Molecular and conventional enumeration techniques were used to quantify rumen bacteria, fungi and protozoa, and protein synthesis was predicted from estimates of urinary purine excretion. The total number of cellulolytic bacteria, including populations of Fibrobacter succinogenes and Ruminococcus spp., was significantly lower in sheep supplemented with calliandra and these populations increased when animals were treated with PEG. By contrast, protozoa and fungi and the microbial group containing Bacteroides-Porphyromonas-Prevotella bacteria appeared to be less affected. The efficiency of microbial protein synthesis in the rumen was not altered significantly. CONCLUSION: Calliandra caused significant shifts in rumen microbial populations without changing the efficiency of protein synthesis. SIGNIFICANCE AND IMPACT OF THE STUDY: The effect of calliandra tannins on rumen digestion may result more from complexing with nutrients than direct inhibition of micro-organisms.

Alpha-tocopherol supplementation decreases the oxidative susceptibility of LDL in renal failure patients on dialysis therapy.

Atherosclerotic cardiovascular disease is the leading cause of death in patients with end stage renal disease (ESRD) who have undergone dialysis treatment. The oxidation of low density lipoprotein (LDL) appears to be a crucial step in the pathogenesis of atherosclerosis. The increased oxidative stress and attendant increased oxidizability of lipoproteins, such as LDL could contribute to the accelerated atherosclerosis in dialysis patients. Since alpha-tocopherol (AT) is the major antioxidant in LDL, the aim of the present study was to test the effectiveness of RRR-AT supplementation (800 I.U. per day) for 12 weeks on the susceptibility of LDL to oxidation. The study subjects comprised patients with chronic renal failure on hemodialysis (HD), peritoneal dialysis (PD), and age and sex matched controls (C). Plasma fatty acids, lipoproteins and AT levels were measured in these subjects before and after supplementation. Also, LDL AT and oxidizability was studied. LDL was isolated by ultracentrifugation at baseline and after 12 weeks of supplementation, and subjected to a 5-h time course of copper catalyzed oxidation. Oxidation was measured by the formation of conjugated dienes (CD) and lipid peroxides (LP). Supplementation with AT did not alter the plasma lipid or lipoprotein profile of these subjects. Plasma lipid-standardized AT and LDL AT concentrations were not different among the groups at baseline. AT supplementation significantly increased plasma lipid-standardized AT (C=150%, HD=149%, PD=217%, P<0.001) and LDL AT concentrations (C=94%, HD=94%, PD=135%, P<0.003). AT enrichment of LDL resulted in a significant prolongation in conjugated diene lag phase in all groups (C=34%, HD=21%, PD=54%, P<0.02). Lipid peroxide lag phase was also increased significantly in C (27%,) and PD (40%) groups after AT supplementation (P<0.01). There was a significant positive correlation between plasma lipid standardized AT and lag phase (r=0. 54, P=0.0003). Overall, AT decreased the susceptibility of LDL to oxidation in patients with chronic renal failure but the benefit appears to be greater in patients on PD. Therefore, AT supplementation may also provide a measure of protection against CAD in patients with chronic renal failure on dialysis therapy.

Isolation and characterization of proteolytic ruminal bacteria from sheep and goats fed the tannin-containing shrub legume Calliandra calothyrsus.

Tannins in forages complex with protein and reduce the availability of nitrogen to ruminants. Ruminal bacteria that ferment protein or peptides in the presence of tannins may benefit digestion of these diets. Bacteria from the rumina of sheep and goats fed Calliandra calothyrsus (3.6% N and 6% condensed tannin) were isolated on proteinaceous agar medium overlaid with either condensed (calliandra tannin) or hydrolyzable (tannic acid) tannin. Fifteen genotypes were identified, based on 16S ribosomal DNA-restriction fragment length polymorphism analysis, and all were proteolytic and fermented peptides to ammonia. Ten of the isolates grew to high optical density (OD) on carbohydrates (glucose, cellobiose, xylose, xylan, starch, and maltose), while the other isolates did not utilize or had low growth on these substrates. In pure culture, representative isolates were unable to ferment protein that was present in calliandra or had been complexed with tannin. One isolate, Lp1284, had high protease activity (80 U), a high specific growth rate (0.28), and a high rate of ammonia production (734 nmol/min/ml/OD unit) on Casamino Acids and Trypticase Peptone. Phylogenetic analysis of the 16S ribosomal DNA sequence showed that Lp1284 was related (97. 6%) to Clostridium botulinum NCTC 7273. Purified plant protein and casein also supported growth of Lp1284 and were fermented to ammonia. This is the first report of a proteolytic, ammonia-hyperproducing bacterium from the rumen. In conclusion, a diverse group of proteolytic and peptidolytic bacteria were present in the rumen, but the isolates could not digest protein that was complexed with condensed tannin.

A delivery system for olfactory stimuli.

This paper describes the design of a new method for controlling and administering olfactory stimuli--namely, the hood system. The hood system involves a stream of vaporized odor (at known concentrations) mixed with odorless air and pumped (at a constant flow rate) into an oxygen therapy hood. It is designed to be used with odorants in solution, such as essential oils, as the olfactory stimulus. The use of oxygen therapy hoods allows for the precise control of a constant concentration of odorized air over time, while allowing subjects to breathe normally. The hood system provides a natural administration of olfactory stimuli and the exact determination of the stimulus concentration. The use of this system will allow experimental conditions to be completely defined and results and replication studies to be accurately interpreted. The hood system is portable, cost effective, and constructed from readily available components. It is proposed that the hood system could be adopted to suit a wide range of olfactory research, particularly that in which the effects of chronic exposure to olfactory stimuli on cognition are examined.

Intraoperative albumin administration affects the outcome of cadaver renal transplantation.

The prognostic significance of early malfunction or delayed function after cadaveric renal transplantation is controversial. This study examines the influence of intraoperative management in 438 cadaveric renal transplant recipients on seven posttransplant outcome measures: (1) time of onset of urine output, (2) urine volume, (3) renal function, (4) incidence of delayed function, (5) never-functioning kidney, (6) graft survival, and (7) patient survival. Delayed function, defined as the need for hemodialysis during the first posttransplant week, decreased from 46% in 1982 to 15% in 1990 and was associated with a 25% lower 1-year graft survival rate and a mortality rate of 10% at 3 months, compared with 3% when immediate function was present. The most important factors influencing the outcome were cold ischemia time (P = 0.007), intraoperative administration of albumin (P = 0.0027), duration of surgery (P = 0.020), and recipient age (P = 0.041). A high albumin dose (1.2-1.6 g/kg bodyweight) induced urine output within 30 min in 75% of patients and induced larger urine volumes (7.3 L/24 hr), as compared with the effects of a low dose (0-0.4 g/kg), which induced urine output within 30 min in 39% and only 3.7 L/24 hr. Serum creatinine at 1 week was 3.4 and 5.8 mg/dl for the high and low albumin doses, respectively (P less than 0.0001). Similarly, mean glomerular filtration rates at 1 and 7 days were 33 and 21 ml/min, compared with 47 and 28 ml/min, for the high and low albumin doses, respectively (P less than 0.01). The incidence of delayed function and of never-functioning kidneys declined from 34% and 9% for the low dose to 12% and 1% for the high dose, respectively. Finally, with increasing albumin dose, the graft survival rate at 1 year improved from 59 to 78% (P less than 0.002), and the patient mortality rate at 3 months dropped from 6% to 2%. For albumin dose intervals between the high (1.2-1.6 g/kg) and low (0-0.4 g/kg), the effect on all seven outcome measures was intermediate, generally describing a linear relationship. Weighted least-squares analysis of the relationship of delayed function with high vs. low doses of albumin, mannitol, furosemide, and volumes of crystalloid solutions showed significance only for the albumin effect. High-dose albumin infusion likely produces intravascular volume expansion and achieves a prompt restoration of blood flow, minimizes hypoxic injury, and helps preserve renal tissue. The possibility of other beneficial effects of albumin unrelated to intravascular volume also exists.(ABSTRACT TRUNCATED AT 400 WORDS)

Osteogenetic activity in composite grafts of demineralized compact bone and marrow.

The effects of a composite graft of autologous marrow and demineralized autologous compact bone on the healing of a surgically created bone defect were observed in adult rabbits. A segment of the radius was bilaterally resected, demineralized, and replaced. On one side the bone graft was supplemented with autologous marrow. The new bone formation was measured 14 and 28 days after operation by roentgenography, including planimetry with scintigraphy and autoradiography using 99mTc-labelled MDP. The composite graft, i.e., demineralized compact bone and marrow, had a significantly higher (p less than 0.01) bone formation rate 14 days after operation compared with the graft with demineralized compact bone in the opposite radius. At 28 days, however, there were no differences between the sides. Viable autologous marrow cells and demineralized autologous compact bone graft accelerate the rate of osteogenesis, but only at the beginning of the healing process.

The recipients and results of acupuncture.

A private clinic was established in Los Angeles in late 1972 to perform acupuncture. Most individuals seeking treatment were middle-aged and well educated. All had considerable experience with traditional medical care for their problem. The principal reason for seeking care was relief from chronic pain. Thirteen per cent had received other nontraditional forms of therapy; over one-third indicated that they sought acupuncture as a "last resort." The results of certain psychological tests taken by these patients were within the range of normal. On completion of six or more treatments, 74 per cent said they had been helped; 54 per cent of those followed for three months and 24 per cent contacted one year later were improved. A subgroup of patients who received only temporary improvement had significantly different scores on psychological scales suggesting the results noted in this group may have been due to a "placebo" effect. A significant proportion of those who dropped out of treatment did so because they had achieved the desired benefits.