[Minimum residual leukemic cells in genetically marked brown Norway rat myelocytic leukemia model]

Different methods were used to detect minimal residual leukemic cells (LT 12 nl), which had been genetically marked with E. coli 1 acZ and neo-gene by retrovirus vector mediated gene transfer. The detection levels of flow cytometry based FDG staining and fluorophotometric method based MUG staining were 10(-3) to 10(-4) and 10(-2) to 10(-3), respectively. The method of G 418 selective agar culture was demonstrated as a 10(-4) to 10(-5) levels for the detection of LT 12 nl residual leukemic cells in bone marrow. The results indicated that the selective agar culture can be used as a sensitive method for the study of minimum residual disease in the BNML leukemia model. We have used the selective agar culture to study the distribution of clonal LT 12 nl cells in BNML during minimum residual disease (MRD). A heterogenous distribution pattern of the clonal leukemic cells was found in the genetically marked BNML leukemia model during the MRD phase.

Digitaloid pregnanes promote potassium-sparing diuresis in the guinea pig

The synthesis of 17 alpha-acetoxy-3 beta-[(beta-D-glucopyranosyl)oxy]- 6 alpha-methylpregn-4-en-20-one, the glucoside of medroxyprogesterone acetate (MPA-glu), is described. MPA-glu and 14-amino-20 beta-hydroxy-3 beta-[(alpha-L-rhamnopyranosyl)oxy]-5 beta, 14 beta-pregnane (LND 623), pregnane glycosides that bind to the digitalis receptor, and digoxin, a cardiac glycoside, were infused intravenously into the anesthetized guinea pig. Each of the three steroids significantly enhanced urinary volume and sodium excretion without affecting blood pressure and creatinine clearance. Potassium excretion was markedly enhanced by digoxin but unaffected by MPA-glu or LND 623. These observations conform to previous work that demonstrated, in the rat, potassium-sparing diuresis by the glucoside of 14 beta-hydroxyprogesterone, a cardiotonic pregnane. There is a dissociation between potency to inhibit [3H]ouabain binding and the extra ATPase actions of the digitaloid pregnanes.

The protective effect of colchicine on bleomycin-induced pulmonary fibrosis in rats

With the purpose of evaluating the therapeutic effect of colchicine on lung fibrosis in rats, bleomycin A5 (BLM-A5) was injected intratracheally to produce a lung fibrosis model. The animals were then treated with colchicine, 50 micrograms/d i.m. One month later, collagen fiber deposition scores (stained by Masson trichrome) were significantly lower in the treated group than in the untreated group (P less than 0.01). This result was proved further by assaying total lung hydroxyproline content (P less than 0.05). Histopathologic findings showed that the proliferation of fibroblasts dropped slightly in the treated group as compared with the untreated group. From this study, we conclude that colchicine has certain antifibrotic effects and may be used in the treatment of pulmonary fibrosis.

[Risk factor for acute viral hepatitis: a case-control study]

One hundred and sixty-two patients with acute viral hepatitis in two hospitals were studied between January and December, 1988. The risk factors, epidemiologic features and prognosis of those patients were investigated by case-control and follow-up study. Among the 162 patients, 37.0% were hepatitis A, 40.7% were hepatitis B, and 19.8% were non-A, non-B hepatitis; there were 4 cases of mixed infection and 3 cases of fulminant hepatitis not included in the study. By simple case-control and logistic regression analysis, the patients of hepatitis A more often had history of personal contact with hepatitis cases (OR = 10.56) and of ingesting some contaminated foods (OR = 4.25); hepatitis B more often had history of personal contact with hepatitis cases in their families or elsewhere (OR = 5.66; OR = 4.30 respectively); and hepatitis NANB more often had history of previous clinical hepatitis episode (OR = 6.56), of personal contact with cases of hepatitis (OR = 3.82) and of receiving a blood transfusion (OR = 16.67). Among hepatitis A, B and NANB cases, sequelae of chronic hepatitis after acute phase were found in 0%, 12.1% and 16.7% of cases, respectively.

Structure of simian virus 40 at 3.8-A resolution

The crystallographically determined structure of simian virus 40 shows that the 72 pentamers of viral protein VP1, which form the outer shell, have identical conformations except for the C-terminal arms of their subunits. Five arms emerge from each pentamer and insert into neighbouring pentamers. This tying together of standard building blocks allows for the required variability in packing geometry without sacrificing specificity.

Finite-element model of the human head: scalp potentials due to dipole sources

Three-dimensional finite-element models provide a method to study the relationship between human scalp potentials and neural current sources inside the brain. A new formulation of dipole-like current sources is developed here. Finite-element analyses based on this formulation are carried out for both a three-concentric-spheres model and a human-head model. Differences in calculated scalp potentials between these two models are studied in the context of the forward and inverse problems in EEG. The effects of the eye orbit structure on surface potential distribution are also studied.

[A comparison of the microvascular architecture of the knee joints of humans and Macaca mulatta]

The blood supply and the microvascular architecture of the knee joint in Macaca mulatta were investigated. 24 lower limb specimens were injected with a barium sulfate suspension via the common iliac artery. The results were then compared with human knee joint data obtained by other authors. We found no evident difference in knee joint blood supply between the two species, but a few variances did exist. Therefore we considered it correct to use the knee joint of the Macaca mulatta as a model in medical experiments, but in an experiment on the regional area or some structures of the knee joint, several variances must be considered before drawing conclusions.

[Effect of liuwei dihuang decoction and its compatible prescriptions on lipid peroxide and lipofuscin]

Our experiment has shown that liuwei dihuang Decoction can decrease the contents of lipid peroxide in the serum as well as lipofuscin in the liver of the older mice to the level of the younger ones, while the two compatible prescriptions derived from the decoction, "Three invigorators" and "Three purges", cannot produce the same effect. All the three forms of prescription have no action on the lipofuscin in the heart.

[Anticancer element selenium in liuwei dihuang decoction]

The contents of selenium in Liuwei Dihuang decoction (six traditional Chinese drugs and their decoction, five decoctions in different compatible ways, a complex decoction of all crude drugs) have been determined by fluorescence spectrophotometric method. The result shows that element selenium is rich in Dihuang. The dissolution ratio of selenium in decoctions of each single crude drug is about 30-40%.

[Comparative study on the inhibitory elastase capacity of fructus Forsythiae, radix Salviae Miltiorrhizae, radix Angelicae Sinensis and Ligustrazini]

In this paper elastase capacity was measured with agar radial diffusion using elastin-agar plate. There was a linear correlation between elatase capacity and diameter of agar radial diffusion. Significant inhibitory effects of Fructus Forsythiae, Radix Salviae Miltiorrhizae, Radix Angelicae Sinensis and Ligustrazini Hydrochloridum on elastase were observed and Fructus Forsythiae proved the most effective.

[Dissolution of metronidazole stilus]

Metronidazole stilus is a new preparation to be inserted into periodontal pockets for treatment of periodontitis. The certificate and file number of approval given to this new product were issued by the Ministry of Public Health in August, 1989. Its shape looks like a toothpick and the width, thickness and length are 1.5mm, 0.7mm and 3 cm, respectively. The content of metronidazole in each cm of the stilus is 2.2 mg. We have studied the dissolution of the new preparation by rotation basket method. The kinetic process of dissolution approximates first order kinetics. The K, t0.5 and t0.9 are 0.0624 min-1, 12.8 and 38.6 minutes, respectively. The requirement is that the dissolved percentage should not be lower than 60% of the added amount in 30 minutes. In order to have a dissolution test similar to that of the stilus in dental pockets, we examined the dissolution in static condition. The results showed that a very high dissolution rate appeared in the beginning, but it decreased quickly, and 71.76% of metronidazole was not dissolved until 48 hours. So one insertion per two days for clinical use is suggested.

[Study on the risk factors of low birth weight]

To detect the risk factors of low birth weight in the newborns, a case-control study was conducted in 5 Health Stations of Donge-heng District of Beijing from Sept 1985 to June 1986. The subjects of study consisted of 84 infants of low birth weight and their parents with 301 controls. A 2 x 2 table analysis was used in screening important factors and multiple logistic regression was employed to estimate the relative role played by these factors. The results revealed that factors, such as height of parents, maternal nutritional status, prematurity, parents' exposure to the chemicals, fathers' smoking habit were risk factors of importance ranked in order.

[Microvascular injury effects and possibility of early anastomosis in the maxillofacial region following high velocity missile wound: an experimental study in dogs]

In order to provide the basis of microvascular anastomosis for reconstruction of maxillofacial defects from firearm injury by using vascularized free tissue transplantation, we studied the mechanism and pathology of microvascular injuries and the possibility of their early anastomosis. The dogs' face were wounded by 0.7 g or 1.03 g steel spheres whose muzzle velocity were 1300 m/s or 1500 m/s. The injury effects of microvascular angiograms were recorded through high speed X-ray camera at the impacting moment the specimens of small vessel were collected for light and electron microscopy at different times after wound. Some dogs were used for performing microvascular anastomosis in the wound region at different times after wound. We found that there were temporary cavity effects in maxillofacial firearm wounds, in and around which small vessel blunt injuries were found, which spread 3 cm from the wound edge. Microvascular anastomosis 3 days after the wound could get higher shortterm patency rate. These results support the conclusion that if we use microsurgical methods to repair defects in maxillofacial firearm wound region, the pedicles of the flap should be laid beyond 3 cm from the wound edge, and the reconstructive operation should be done 3 days after the wound.

[Age-related microvascular changes in human skin]

Microvascular changes in 32 biopsies of normal human skin were observed using electronic computer image analysis. Statistical analysis showed a decrease in microvasculature with increase of age, with significant decreases appearing at ages greater than or equal to 20, suggesting that the changes are closely related to aging of human skin.

[Clinical, immunophenotypic and cell cyclic analysis in chronic lymphocytic leukemia]

15 cases of chronic lymphocytic leukemia (CLL) were immunophenotyped with a panel of monoclonal antibodies. 13 cases were B-CLL, which was characterized by CD20+, HLA-Dr+, SmIg+ and CD5+/Em+. 2 cases were T-CLL, one with Ts phenotype and HLA-Dr+ T-Cll in the other. The ratio of G0 + G1 cells in bone marrow of CLL was 91.1 +/- 2.3% (76.0 +/- 5.1% in controls), while S + G2M cells was 8.9 +/- 2.3% (23.9 +/- 5.1% in controls). The ratios of various cyclic cells were similar in bone marrow and in peripheral blood. Prolymphocytoid transformation developed in the late stage in 3 CLL patients. The clinical course, cytochemistry and immunologic changes in CLL were also analysed.

[Molecular cloning, gene structure and subcellular distribution of 7s RNA of rat liver cells]

The cDNA copy of in vitro polyadenylated 7s RNA from rat liver cells have been cloned and sequenced. One clone (p 24) contains a 7 s cDNA fragment with 180 bp from 3'end. Sequence analysis indicated that 7s RNA in rat liver cells showed at least one nucleotide substitution compared with that in rat Novikoff hepatoma cells. Southern blot of rat liver and hepatoma genomic DNA shows that 7s RNA gene is a multigene family (10-20 copies per haploid genome) and these loci seems not to be clustered, but have a dispersed array in the genome. We have determined the subcellular distribution of 7 s RNA in rat liver cell by means of RNA-excess hybridization. The result indicated that 42% 7s RNA exists in cell nuclei. Dot hybridization to RNA from liver cells and hepatoma cells proved that the normal liver cells contain relatively more 7 s RNA than that in hepatoma cells.

[Tracheo-bronchoplasty: a report of 99 cases]

This paper reported 99 patients (10 with benign lesions and 89 malignant tumors) treated by tracheo-bronchoplasty. Postoperative complications occurred in 11 patients. Of whom 5 died of bronchovascular fistulas, respiratory failure, empyema, or spontaneous pneumothorax. On follow-up, among 13 patients with tracheal carcinoma treated by tracheal and/or carinal reconstructions, 4 lived for more than 5 years, 2 more than 3 years, 1 less than 1 year, and 6 died within 2 years. The survival rates of patients with bronchoplasty for lung cancer were 64.5% and 42.9% at 3 and 5 years, respectively.

[Experimental study of antigastroesophageal reflux by preservation of the lower esophageal sphincter]

Gastroesophageal reflux and its resultant esophagitis are common complications following removal of the middle and lower part of the esophagus as well as the gastric cardia with reconstruction by simple esophagogastrostomy. Twenty-one dogs were randomly divided into 3 groups: (1) LES preserving group; (2) Nissen's fundoplication group; (3) Sweet's esophagogastrostomy group. Results by esophageal manometry, X-ray video tape recorder, and pathological examination respectively, 3 months postoperatively were compared. Esophageal manometry showed that the pressure of the preserved LES was still present. X-ray video tape recorder revealed that antireflex function was present in the preserved LES. Pathological examination confirmed no signs of reflux esophagitis in the mucosal specimen of the preserved LES group. We concluded that LES is the main barrier of gastroesophageal reflux. The intrathoracic LES could still have the function of anti-reflux.

Bleomycin hypersensitivity in dyskeratosis congenita fibroblasts, lymphocytes, and transformed lymphoblasts

We studied the responses of several dyskeratosis congenita (DC) cell lines to the DNA strand-cleaving and base-damaging agent bleomycin. Fibroblasts, peripheral blood lymphocytes, and transformed lymphoblasts of six DC patients and an obligate DC heterozygote showed more chromatid breaks than did respective controls exposed to various concentrations of bleomycin during the G2 phase of the cell cycle (P less than 0.0001). Unsynchronized DC fibroblasts in culture also showed decreased survival, compared to normals, following bleomycin treatment. DC lymphocytes treated with bleomycin for the final 24 h of culture showed more chromatid- and chromosome-type damage than did normals (P less than 0.0001) or G0-treated DC lymphocytes. Spontaneous chromosome breakage was normal in all six DC cell lines. The ability to distinguish affected and heterozygous DC cells without spontaneous chromosome instability from normals on the basis of their bleomycin hypersensitivity provides a marker for future studies of the pathogenesis of this disorder.