Search PubMed⌕ Search

Biomedical subjects

Y Lu

Publications and source records attributed to Y Lu.

At least 865 records · Page 48Linked to original sources
PubMed1993

The esterified plasma fatty acid profile is altered in early HIV-1 infection.

Previous studies have shown that alterations in micronutrient utilization occur in patients with Acquired Immune Deficiency Syndrome. In this study, total plasma fatty acid composition was measured in 36 homosexual men infected with the Human Immunodeficiency Virus 1 (HIV-1) and in 17 HIV-1 seronegative homosexual men in order to evaluate differences associated with early HIV-1 infection. Immunologic assessment included CD4 cell number count and lymphocyte blastogenesis in response to the mitogens phytohemagglutinin (PHA) and pokeweed (PWM). The mean total amount of omega 6 polyunsaturated fatty acids (18:2 and 20:4) was significantly lower in the HIV-1 seropositive subjects (38 +/- 8.1% SD) as compared to HIV-1 seronegative subjects (43 +/- 4.2%; P = 0.0027). This was also reflected in a higher level of total saturated fatty acids (16:0 and 18:0) in HIV-1 seropositive subjects (30 +/- 2.2% vs. 26 +/- 2.8%; P = 0.0001). The ratio of linoleic to arachidonic acid (18:2 to 20:4) was higher in the HIV-1 seropositive group (6.76 +/- 4.88) compared to the HIV-1 seronegative group (4.86 +/- 1.37; P = 0.0213). The response to PHA in seropositive subjects correlated inversely with total plasma omega 6 fatty acids (r = -0.36; P = 0.027), and directly with the 18:2 to 20:4 ratio (r = 0.33; P = 0.046). CD4 cell counts and the response to PWM did not correlate with plasma fatty acid levels in HIV-1 seropositive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Intravitreal pharmacokinetics of liposome-encapsulated amikacin in a rabbit model.

BACKGROUND: Intravitreal injection of antibiotics has become a standard therapy for bacterial endophthalmitis. The duration of effective antimicrobial levels in the vitreous after single injection, however, may not be long enough to get optimal response. The authors prepared liposome-encapsulated amikacin for prolonging the duration of intravitreal therapeutic concentrations and investigated the intravitreal pharmacokinetics of the liposomes and amikacin in phosphate buffer solution (PBS) as control. METHODS: The liposome-encapsulated amikacin was prepared by reverse-phase evaporation method. The intravitreal pharmacokinetics of the liposomes was compared with amikacin in PBS by fluorescence polarization immunoassay. Albino rabbits were randomly distributed into 12 groups. Rabbits in groups 1 to 6 and in groups I to VI (control groups) received an intravitreal injection of the liposome-encapsulated amikacin and amikacin in PBS, respectively. RESULTS: The encapsulation rate of amikacin was 91%. The time of 50% spontaneous degradation (half-life) of the liposomes in PBS (38 degrees C, pH 7.4) was 47.6 days, and the time of 50% release (half-life) of the drug from the liposomes in PBS was 84.8 hours. The vitreous amikacin concentrations in groups 1 to 6 were significantly greater (P < 0.05) than those in control groups I to VI in every time interval, except in groups 1 to 3 at 1 hour after injection. The difference was particularly obvious in the endophthalmitis groups. The clearance of encapsulated amikacin in vitreous appeared to be related to the state of blood-ocular barrier and to the structural integrity of vitreous. The distribution, the absorption, and the elimination of encapsulated amikacin in vitreous showed the first-order kinetics. CONCLUSION: The liposome-encapsulated amikacin prolonged half-life of the drug in vitreous. The results of the pharmacokinetic analysis suggested that in endophthalmitis, especially in severe cases, the liposomes may be preferable to conventional preparation.

Absorption↗
PubMed1993

Hypocapnia worsens arterial blood oxygenation and increases VA/Q heterogeneity in canine pulmonary edema.

BACKGROUND: Hyperventilation frequently is employed to reduce carbon dioxide partial pressure in patients in the operating room and intensive care unit. However the effect of hypocapnia on oxygenation is complex and may result in worsening in patients with preexisting intrapulmonary shunt. To better define the interplay between hypocapnia and oxygenation, the effects of hypocapnia and hypercapnia on the matching of ventilation (VA) and perfusion (Q) were studied in dogs with oleic acid-induced pulmonary edema, using the multiple inert gas elimination technique. METHODS: Eight pentobarbital-anesthetized, closed-chested dogs were administered 0.06 ml/kg of oleic acid at least 150 min prior to study. Ventilation was set with an FIO2 of 0.90, a tidal volume of 20 ml/kg, and a respiratory rate of 35 breaths/min. The arterial carbon dioxide tension (PaCO2) was varied in a randomized order to three levels (26, 38, and 50 mmHg) by altering the amount of CO2 in the inspired gas mixture. Gas exchange was assessed by true shunt, dead space, the log standard deviation of the perfusion (log SDQ) and the ventilation (log SDV) distributions, and the tracer inert gas arterial-alveolar difference ([a-A]D) area. RESULTS: Cardiac output (4.1 +/- 0.4 L/min), mean pulmonary artery pressure (25 +/- 1 mmHg), inert gas shunt (22 +/- 3%), and dead space (38 +/- 4%) during normocapnia were not different from that during hypocapnia and hypercapnia. Hypocapnia increased (P < .05) the alveolar-arterial oxygen tension difference (P[A-a]O2) and decreased (P < .05) the arterial blood oxygen tension (PaO2, 181 +/- 33 mmHg vs. 221 +/- 35 mmHg with normocapnia). P[A-a]O2 and PaO2 were unaffected by hypercapnia. During hypocapnia, VA/Q inequality increased, demonstrated by an increase (P < .05) in log SDQ (1.60 +/- 0.15 vs. 1.35 +/- 0.19 with normocapnia) and in the [a-A]D area (0.63 +/- 0.09 vs. 0.50 +/- 0.09 with normocapnia) indexes of VA/Q heterogeneity. During hypercapnia, the [a-A]D area (0.63 +/- 0.11) and log SDV (1.13 +/- 0.10 compared to 0.97 +/- 0.12 with normocapnia) also were increased (P < .05). With hypocapnia, there was a small but insignificant increase in blood flow to shunt and low VA/Q areas (29 +/- 4% compared to 26 +/- 4% with normocapnia). In the presence of a high FIO2, this small increase in shunt and low VA/Q may result in a significant decrease in PaO2. CONCLUSIONS: Both hypocapnia and hypercapnia were associated with an increased VA/Q inequality. However, PaO2 decreased and P[A-a]O2 increased with only hypocapnia. These results suggest that hyperventilation to reduce PaCO2 may be detrimental to arterial PO2 in some patients with lung disease.

Animals↗
PubMed1993

Effect of inspired CO2 on ventilation and perfusion heterogeneity in hyperventilated dogs.

We studied the effect of inspired CO2 on ventilation-perfusion (VA/Q) heterogeneity in dogs hyperventilated under two different tidal volume (VT) and respiratory rate conditions with the use of the multiple inert gas elimination technique. Dogs anesthetized with pentobarbital sodium were hyperventilated with an inspired fraction of O2 of 0.21 by using an increased VT (VT = 30 ml/kg at 18 breaths/min) or an increased respiratory rate (VT = 18 ml/kg at 35 breaths/min). The arterial CO2 tension (PaCO2) was varied to three levels (20, 35, and 52 Torr) by altering the inspired PCO2. The orders of type of ventilation and PaCO2 level were randomized. Compared with normocapnia, VA/Q heterogeneity was increased during hypocapnia induced by increased respiratory rate ventilation, which was indicated by an increase in dispersion indexes and arterial-alveolar inert gas partial pressure difference areas (P < 0.01). In contrast, VA/Q heterogeneity was not affected by hypocapnia when a large VT ventilation was used. Under the conditions of our study, hypercapnia did not result in statistically significant changes in VA/Q heterogeneity with either type of ventilation. Increased VT ventilation reduced dead space at all PaCO2 levels (P < 0.01) and reduced the log standard deviation of the ventilation distribution during normocapnia (P < 0.05) and hypocapnia (P < 0.01). We conclude that hypocapnia increased VA/Q heterogeneity when hyperventilation was achieved with a rapid respiratory rate. Therefore, a lack of improvement in VA/Q matching with inhaled CO2 may be associated with the use of a large VT. These data suggest that hypocapnic bronchoconstriction may be important in mediating hypocapnia-induced VA/Q inequality in dogs.

Administration, Inhalation↗
PubMed1993

[Fibrous dysplasia of jaw and facial bones:A combined analysis of clinic,radiologic and histopathologic diagnosis of 117 cases]

A clinical-radiologic-histopathologic review of 106 cases of fibrous dysplasia involving the jaws is presented. Ninety eight patients onset in the first and second decades.Fifteen cases were polyostotic and the remaining cases were were monstotic.Radiologicaly,the lesions showed and extending growth pattern,poor definite border and slight pattern,poor definite border and slight involvement of teeth.The radiographic features were classified into four types:ground grass (52.0%),sclerotic(8.0%),cystic-like(8.0%) and mixed type (32.0%).Histologically the lesions were characterized by a cellular fibrous stroma that contain varying amounts of mineralized substance,represented by woven bone(63.0%),lamellar bone(30.0%) and cementum-like structure(7.0%).The final definitive diagnosis requires the combined evaluation of clinic,radiologic and histopathologic findings.

Journal Article↗
PubMed1993

Management of major arterial injuries of the limbs in 166 cases.

The charts of 166 patients with major arterial injuries (175 arterial repairs) inflicted during periods of peace and war time were reviewed. One hundred and sixty-seven (95%) of the arteries repaired remained patent. Nine patients had limbs which developed ischemic contracture. Nine patients required amputations. Follow-up data was obtained from seventy-five patients with an average follow-up of five years and one month (six months to thirty years). Early diagnosis, prompt treatment including fasciotomies when indicated, complete debridement, appropriate coverage, meticulous surgical technique, and simultaneous treatment of concomitant injuries are all crucial factors in successful limb salvage. Major arterial injuries of the limb occur frequently in our patient population, especially in time of war. Successful treatment of major arterial injuries may be life-saving, as well as allowing limb salvage and restoration of limb function. The purpose of this study is to review our experience with repair of major arterial injuries.

Adolescent↗
PubMed1993

[Analysis of malarial infection among technical personnel dispatched to Burkina Faso, West Africa].

Fifty-six technical personnel, who had been dispatched to carry out the Chinese-aid project in Burkina Faso, West Africa (a highly prevalent area of malaria and infected by asexual from of plasmodium), developed malaria within one year after the repatriation from that country. The number of paroxysm of this disease per individual varied from one to six, with an average of 2.8.

Burkina Faso↗
PubMed1993

[X-ray computed tomography in the diagnosis of peritoneal and retroperitoneal neoplasms].

CT findings of peritoneal and retroperitoneal neoplasms were evaluated in 24 patients. The accuracy of CT in locating peritoneal and retroperitoneal tumors was 87% and in differentiating benign from malignant ones 96%. It is difficult to evaluate the tumors histopathologically. We suggest that CT scan be preferable in diagnosis of tumors in that area.

Adolescent↗
PubMed1993

[The crystal structure atlas data base system for chemical constituents of Chinese traditional and folk medicine].

The atlas data base system for chemical constituents of Chinese traditional and folk medicine is the first one for single crystal structure in China. It includes about 250 crystal structures of chemical ingredients of Chinese traditional and folk medicine. It has searching, plotting and computing functions. It is a useful reference base. All softwares are written in dbaseIII, FORTRAN and Assembler Languages. They can be run on PC-286,386,486 and their compatible microcomputers.

Crystallography↗
PubMed1993

CT scanning of spinal injuries.

Ninety-one patients with spinal injuries were studied by CT scanning. A comprehensive classification of spinal injuries was proposed according to the mechanism of trauma, the concept of three-column anatomical structure of the spine and the degree of spinal canal stenosis. CT scanning was advantageous in the diagnosis of spinal injuries such as clear detection of the three-column anatomical structure of the spine and spinal canal, demonstration of fracture lines in all 3 planes, determination of the amount of displacement of bony fragment into the spinal canal, assessment of spinal stability or instability, and restricted movement of the patient. The key points in general CT diagnosis, its role and limitation in the diagnosis of spinal injuries were discussed. The authors conclude that combined comprehensive classification of spine injuries is helpful in planning suitable treatment for the patient and predicting prognosis.

Adolescent↗
PubMed1993

[Studies on the chemical constituents of Ventilago leiocarpa Benth].

Three anthraquinones (1-3) and two naphthoquinones(4,5) were isolated from the root of Ventilago leiocarpa Benth (Rhamnaceae). On the basis of spectroscopic data and X-ray diffraction analysis compound 5, ventilagolin, was shown to be a new naphthoquinone occurring as a racemate.

Drugs, Chinese Herbal↗