A comparison of the effect of benzopyrones and other drugs with anti-inflammatory properties on acid and neutral protease activity levels in various tissues after thermal injury

Generally, the benzopyrones enhanced acid protease activity levels in the oedema fluid and the extracellular compartment of the skin. This is the region where thermal injury has its greatest impact. The proteolysis induced by the drugs in this region represents a means of rapidly reducing some of the derangements which the thermal injury has caused. Levamisole also enhanced acid protease activity levels in the serum and extracellular compartment of the skin 6 hours after thermal injury, while Reparil had the same effect at 24 hours. Generally the benzopyrones had little or no effect on neutral protease levels, while levamisole and Reparil caused their depression. The later effects could possibly be attributed to serum deactivation or to inhibition of their release. The enzyme enhancing activity of these drugs has been shown to correlate remarkably well with their oedema reducing ability. Generally, those which increased enzyme activity levels the most were the most effective in reducing the oedema. The cells upon which the drugs exert their effects in thermal oedema mainly seem to be the macrophages; the fibroblasts seem to be of secondary importance. This is to be contrasted with their action in the initial stages of lymphoedema where they are believed to stimulate the neutrophils. The net result of the proteolysis is many small fragments which can rapidly leave the injured tissue thus releasing the oedema fluid.     

The modern enigma of radiation enteropathy: sequelae and solutions

With the extended indications for abdominal and pelvic radiation therapy, administered at higher dosage levels, an increased incidence of radiation injury to the intestine can be anticipated. Increased efforts are urgently needed to develop innovative methods in the detection, prevention, and management of radiation-induced intestinal injury. Fifty cases of radiation enteropathy have been reviewed to highlight problems in management and to suggest preventive and therapeutic measures, both surgical and nonsurgical.     

Preferential retention of the mink chromosome group in somatic cell hybrids of Chinese hamster and American mink

The chromosomal complement was studied in 57 independent clones of hybrid cells obtained in six experiments for fusion of Chinese hamster and American mink cells. Various mink chromosomes in hybrids of concern are lost. It is shown when a small number of mink chromosomes are retained in hybrid clones, chromosomes 6, 9, 10, 12, 13, 14 and X segregate in a similar way and are preferentially retained in these clones. When a considerable number of mink chromosomes are detained in hybrid clones, the segregation mode is close to a random one.     

Nitric oxide and beta-adrenergic agonist-induced bronchial arterial vasodilation

In anesthetized sheep, we measured bronchial blood flow (Qbr) by an ultrasonic flow probe to investigate the interaction between inhaled nitric oxide (NO; 100 parts/million) given for 5 min and 5 ml of aerosolized isoetharine (1.49 x 10(-2) M concentration). NO and isoetharine increased Qbr from 26.5 +/- 6.5 to 39.1 (SE) +/- 10.6 and 39.7 +/- 10.7 ml/min, respectively (n = 5). Administration of NO immediately after isoetharine further increased Qbr to 57.3 +/- 15.1 ml/min. NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME; 30 mg/kg, in 20 ml saline given i.v.) decreased Qbr to 14.6 +/- 2.6 ml/min. NO given three times alternately with isoetharine progressively increased Qbr from 14.6 +/- 2.6 to 74.3 +/- 17.0 ml/min, suggesting that NO and isoetharine potentiate vasodilator effects of each other. In three other sheep, after L-NAME three sequential doses of isoetharine increased Qbr from 10.2 +/- 3.4 to 11.5 +/- 5.7, 11.7 +/- 4.7, and 13.3 +/- 5.7 ml/min, respectively, indicating that effects of isoetharine are predominantly mediated through synthesis of NO. When this was followed by three sequential administrations of NO, Qbr increased by 146, 172, and 185%, respectively. Thus in the bronchial circulation, there seems to be a close interaction between adenosine 3',5'-cyclic monophosphate- and guanosine 3',5'-cyclic monophosphate-mediated vasodilation.     

Reflections on replacement

In the United States, the total fertility rate is about 1.9 births per woman, down from a peak of 3.2 a generation ago and below the replacement level of 2.1 children. The proportion of women who will never have children has risen from 8% a generation ago to approximately 18% in 1993. The increase in the proportion of women in the labor force, a proximate explanation of the recent decline in intended fertility, is expected to continue. The demographic consequence is declining population with an older age structure. A pronatalist policy to alleviate this outcome, through monetary transfers from taxpayers to potential parents, is not only unlikely to succeed, it is politically unfeasible. An alternative solution, immediately effective but politically unpalatable, would be a generous immigration policy. Even with replacement level fertility, the population is destined to become much older. This inevitable aging of the population should be countered by appropriate institutional transformations: 1) with lower fertility, a larger proportion of women will be available to participate in the labor force to generate taxes needed to support a larger number of pensioners; 2) the institutional practice of ascribing a dependent status to anyone above a particular age can be changed; 3) concerns that an older labor force will have an obsolete education (and fewer years of it) can be countered by changing access to education. Yet, the most serious question is not merely the net reproduction rate, but producing adequate numbers of new adult citizens with responsibility and technical training in the modern world. The fundamental process of socializing children may be jeopardized by replacing the full-time parent with the hired care-giver, the peer group, and the television set. The attenuation of the bonds between parent and child may devalue the worth of childbearing itself. These portentous consequences deserve consideration.     

Customization of ZrO2 loose/tight bilayer ultrafiltration membranes by reverse micelles-mediated aqueous sol-gel process for wastewater treatment

Two types of spherical zirconyl oxalate aqueous sols were successfully customized by a reverse micelles-mediated aqueous sol-gel process, and the sols were sequentially spin-coated on porous supports to prepare ZrO₂ loose/tight bilayer ultrafiltration membranes. After three times of spin-coating process, a defect-free ZrO₂ loose ultrafiltration membrane with pure water permeability of 110.5 ± 2.25 L m^?2 h^-1 bar^-1, molecular weight cut-off (MWCO) of 16.5 kDa and excellent rejection of up to 97.5 % for bovine serum albumin was fabricated. Then, the loose ultrafiltration membrane was used as a substrate to prepare ZrO₂ tight ultrafiltration membrane. Performances of tight ultrafiltration membrane regarding to permeability, retention of polyethylene glycol and treatment of dyes wastewater were evaluated. The tight ultrafiltration membrane with a thickness of 200 nm exhibited a pure water permeability of 22.5 ± 0.3 L m^-2 h^-1 bar^-1 and MWCO of 1150 Da. Additionally, the rejections of methyl red and methyl orange by the tight ultrafiltration membrane were both <65 %, while of alizarin red, direct red, bromocresol green and methyl blue achieved maximum values of 98.5 %, 99.2 %, 99.5 % and 99.6 %, respectively. The fouled membranes could restore the virgin performance for reuse by cleaning and low-temperature calcination.