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Biomedical subjects

M Li

Publications and source records attributed to M Li.

At least 1,135 records · Page 63Linked to original sources

The efficacy of high-dose 4'epidoxorubicin in hepatocellular carcinoma.

An open phase II study of high-dose 4'epidoxorubicin (90 mg/m2) was conducted in 33 patients with inoperable hepatocellular carcinoma. Three out of the 33 (9%) patients showed tumour response. The treatment was relatively well tolerated with a moderate degree of haematological toxicity and alopecia, and a mild degree of nausea and vomiting. The overall median survival was 72 days with a prolongation in the patients who showed some response.

Adult↗

The wounding characteristics of spherical steel fragments in live tissues.

This paper reports the wounding effectiveness tests of four kinds of spherical steel fragments, striking against live tissues at various velocities. The most pronounced wound characteristic for the spherical fragments was that the entrances were larger than the exits; the higher the striking velocity, the larger the size of the wound. The skin near the entrance tended to be torn away when the striking velocity was above 1,200 m/s. As a general rule, most exits appeared to be circular with a diameter slightly bigger than that of the fragment. Shapes of the wound channels were conic in general. The channel volumes were proportional to the striking velocities of the fragments; in the case of two spheres having the same striking energy, the small one would produce larger volume of wound channel and amount of debrided tissues. The energy release rate for smaller fragments was higher than that for larger ones.

Animals↗

An estimation of the physical characteristics of wounds inflicted by spherical fragments.

Based on test results of projecting four different types of spherical fragments, diameters of which were 3.175 mm, 4.763 mm, 5.56 mm, and 6.35 mm, respectively, into the biological soft tissues and the soap blocks used as simulants, an estimation of the physical characteristics of wounds inflicted by spherical fragments was established in this paper. With impact velocities in the range of 450-1,500 m/s, all four types of spherical fragments showed little variation in drag coefficients for each medium. Some specific wound characteristics such as amount of debrided tissue, volume of the wound channel, etc., can be predicted as functions of energy transfer for spherical fragments of less than 1 gram.

Animals↗

Diethyl ether as a substrate for acetone/ethanol-inducible cytochrome P-450 and as an inducer for cytochrome(s) P-450.

The ability of diethyl ether to serve as a substrate for microsomal and purified cytochrome P-450 (P-450) and as an inducer for rat hepatic microsomal monooxygenase activities was examined. Microsomal oxidation of ether to acetaldehyde, as monitored by high pressure liquid chromatography, was elevated 3- to 5-fold by treatment of rats with acetone or ethanol, 1.5- to 2-fold by treatment with ether, and only slightly by phenobarbital treatment. Ether also induced N-nitrosodimethylamine demethylase by up to 2-fold and 7-pentoxyresorufin dealkylation by up to 10-fold. These trends agreed with immunoblot experiments in which ether was a weak inducer of the P-450 isozyme IIE1 (encoded by the rat gene P450IIE1), but a stronger inducer of IIB1. A monoclonal antibody against IIE1 inhibited the deethylation by 78% in microsomes from acetone-treated rats and by 45% in controls. N-Nitrosodimethylamine, as well as common inhibitors of IIE1 such as hexane, benzene, pyrazole, and phenylethylamine, strongly inhibited ether deethylation. Using microsomes from acetone-induced rats, the apparent Km for deethylation was 13.4 +/- 2.4 microM and the Vmax was 8.2 +/- 0.2 (nmol of acetaldehyde/min/nmol of P-450). The Km for the controls was 71.3 +/- 9.5 microM. The rates of deethylation at 1 mM ether by purified, reconstituted IIE1 and IIB1 were 4.2 and 0.42 (nmol of acetaldehyde/min/nmol of P-450), respectively. Cytochrome b5 stimulated the rate due to IIE1 apparently by a decrease in the Km. These findings, along with previous work showing marked inhibition by ether of IIE1-dependent reactions, strongly support a major role for this isozyme in ether metabolism.

Acetone↗

Endemic goitre in central China caused by excessive iodine intake.

Thyroid status was examined in children from two villages in central China where the iodine concentrations in drinking water were 462.5 and 54 micrograms/l. Goitres were present in 65% (n = 120) and 15.4% (n = 51), respectively. All children in both groups were clinically euthyroid and neurologically normal. Growth measurements and intellectual performance were similar in the two groups. Children from the high-iodine village had a lower mean serum triiodothyronine and higher serum free thyroxine and serum thyroid-stimulating hormone concentrations than the children from the control village. 2 cases of overt hypothyroidism were detected in the high-iodine village.

Adolescent↗

Vomiting in children following head injury.

The criteria for hospital admission of children who have suffered a minor head injury are highly subjective. Often the presence of post-traumatic emesis becomes an influential factor, but the mechanisms that trigger emesis following minor head injuries are not known. From a prospective study of 96 consecutive children with their first mild head injury (GCS 13-15) and a retrospective study of 29 consecutive more seriously injured children (GCS 8-12), we conclude that post-traumatic emesis is more common: (1) following minor head injuries than following more severe head injuries (P less than 0.05); (2) in children over 2 years old; (P less than 0.001); (3) in children injured within an hour of a meal or snack (p less than 0.001). The presence of a skull fracture or the site of the impact does not influence the incidence or duration of post-traumatic emesis. Retching and vomiting generally subside within 3 h in children injured within an hour of a meal or snack. When vomiting appears in children injured more than an hour after a meal or a snack, it may be quite protracted (mean = 7.5 h). Children over 2 years of age with post-traumatic emesis who are neurologically stable following a mild head injury that occurred within an hour of a meal or snack can be expected to improve quickly. Their counterparts injured more than an hour after a meal or snack are likely to remain distressed much longer and are best admitted to hospital.

Age Factors↗

The gut as a portal of entry for bacteremia. Role of protein malnutrition.

The current studies were performed to determine the influence of malnutrition alone or in combination with endotoxemia in promoting bacterial translocation from the gastrointestinal tract. Bacterial translocation did not occur in control, starved (up to 72 hours), or protein-malnourished (up to 21 days) mice not receiving endotoxin. Bacterial translocation to the mesenteric lymph nodes (MLNs) occurred in 80% of control mice 24 hours after receiving endotoxin (p less than 0.01). However, the combination of malnutrition plus endotoxin was associated with a higher incidence of translocation to the systemic organs (p less than 0.01), and higher numbers of bacteria per organ (p less than 0.01), than was seen in normally nourished mice receiving endotoxin. Additionally, mice that were protein malnourished were more susceptible to the lethal effects of endotoxin than were control animals, and the mortality rate was directly related to the degree of malnutrition (R2 = 0.93) (p less than 0.05). Histologically, endotoxin in combination with protein malnutrition resulted in mechanical damage to the gut mucosal barrier to bacteria. Thus, in the mice that were protein malnourished the spread of bacteria from the gut could not be controlled nor could translocated bacteria be cleared as well as normally nourished mice receiving endotoxin. These results support the concept that under certain circumstances the gut may serve as a clinically important portal of entry for bacteria.

Animals↗

The production of reactive oxygen species in mice infected or immunized with Plasmodium berghei.

The capacity of peritoneal exudate cells (PEC) obtained from mice infected or immunized with Plasmodium berghei to produce reactive oxygen species (ROS) and the biological basis of this response was investigated, using luminol-dependent zymosan-triggered chemiluminescence (CL). CL response of PEC from infected mice increased at the early stage but was significantly depressed at the later course of the infection. A similar biphasic activity of peroxidase was also observed in PEC from infected mice. On the other hand, PEC from immunized mice exhibited concomitant increases of the ability to produce CL, the activity of peroxidase and the expression of Fc and C3 receptors on cell surface. Compared with the controls, PEC from immunized mice showed an elevated background CL, responded more rapidly to the stimulation and generated considerably higher CL when triggered with opsonized zymosan. The data suggest that phagocytes in immunized mice are active in the production of ROS while those in infected mice are less active, and the inhibition of the ability of phagocytes to produce ROS may be one of the mechanisms for the parasites to escape from host immune system.

Animals↗