Requirement of human immunodeficiency virus type 1 nef for in vivo replication and pathogenicity

The role of human immunodeficiency virus type 1 (HIV-1) accessory genes in pathogenesis has remained unclear because of the lack of a suitable in vivo model. The most controversial of these genes is nef. We investigated the requirement for Nef for in vivo replication and pathogenicity of two isolates of HIV-1 (HIV-1JR-CSF and HIV-1NL4-3) in human fetal thymus and liver implants in severe combined immunodeficient mice. HIV-1JR-CSF and HIV-1NL4-3 differ in their in vitro phenotypes in that HIV-1JR-CSF does not induce syncytia and is relatively noncytopathic, while HIV-1NL4-3 is highly cytopathic and readily induces syncytia. The nef mutants of both isolates grew with kinetics similar to those of parental virus strains in stimulated peripheral blood lymphocytes but demonstrated attenuated growth properties in vivo. HIV-1NL4-3 induced severe depletion of human thymocytes within 6 weeks of infection, whereas its nef mutant did not. Thus, HIV-1 Nef is required for efficient in vivo viral replication and pathogenicity.

High density cultivation of genetically-engineered CHO cell lines with microcarrier culture systems

Genetically-engineered CHO cell lines, r beta-13 and CLF-8B2, were cultivated with the MC-1 microcarrier culture system. The cell density could be enhanced by increasing the concentration of microcarrier. At a microcarrier concentration of 10 mg/ml, the cell density could reach 4 to 5 x 10(6) cells/ml. It was shown that these cell lines would spontaneously release from the microcarrier to attach to and proliferate on fresh microcarriers. We were thus able to scale up cultivation using a simple method, i.e. by adding fresh microcarriers and medium directly into the culture system to about 2, 4 or 8 times the original volume. Using a perfusion culture system, we have successfully cultivated CLF-8B2 cells in a 2 L bioreactor for several weeks at medium perfusion rates of 0.5 to 3 working volumes. Prourokinase was stably secreted.

Experimental study of the effects of "fractional" gating on flow measurements

Velocity encoded phase imaging is subject to errors from phase and amplitude variations of the k-space data caused by beat-to-beat variations of the flow. Fractional cardiac gating is defined as asynchronous gating with each phase encode step occupying a fixed fraction of the RR interval. The gating fraction is the inverse of the number of phase encode steps taken per RR interval. Studies in normal subjects show that deviations and standard errors of ascending and descending aorta flow measurements are significantly greater with decreased gating fraction. Significant errors occur when gating does not separate systolic and diastolic data. The studies establish a graded trade-off between flow measurement accuracy and precision with imaging time, and show that standard nongated phase contrast measurements of strongly pulsatile flow are unreliable.

Immune response to human papillomavirus type 16 E6 gene in a live vaccinia vector

Immunization of mice with a recombinant vaccinia virus expressing the human papillomavirus type 16 (HPV-16) E6 gene elicits specific antibody, proliferative and cytotoxic T lymphocyte responses. T and B cell epitopes were mapped by using synthetic peptides. This study provides the background to future investigation aimed at developing prophylactic and therapeutic vaccines against HPV-16 infection and cervical cancer.

[The effects of phenytoin and carbamazepine on the cognitive function of epileptic patients]

We made a comparative study of the cognitive function of 60 epileptic patients before and after the use of phenytoin (DPH) and carbamazepine (CBZ). Five types of neuropsychological tests were adopted. Although both DPH and CBZ affected cognitive function, the degrees of their effects were not the same. DPH affected cognitive function in a broad field, including concentration, remembrance, psychological motor speed and mental processing, whereas CBZ had only slight effect on perception and motor speed. It is stressed that cognitive function disorder caused by antiepileptic drugs should be early detected by synchronous examinations of the level of antiepileptic drugs and the neuropsychological functions.

The SCID-hu mouse as a model for HIV-1 infection

During normal fetal ontogeny, one of the first organs to harbour CD4-positive cells is the thymus. This organ could therefore be one of the earliest targets infected by human immunodeficiency virus type 1 (HIV-1) in utero. HIV-1-infected cells and pathological abnormalities of the thymus have been seen in HIV-1-infected adults and children, and in some fetuses aborted from infected women. Studies of HIV-1 pathogenesis have been hampered by lack of a suitable animal model system. Here we use the SCID-hu mouse as a model to investigate the effect of virus infection on human tissue. The mouse is homozygous for the severe combined immunodeficiency (SCID) defect. The model is constructed by implanting human fetal liver and thymus under the mouse kidney capsule. A conjoint human organ develops, which allows normal maturation of human thymocytes. After direct inoculation of HIV-1 into these implants, we observed severe depletion of human CD4-bearing cells within a few weeks of infection. This correlated with increasing virus load in the implants. Thus the SCID-hu mouse may be a useful in vivo system for the study of HIV-1-induced pathology.

Preliminary experience in HDR brachytherapy for 72 nasopharyngeal carcinoma patients

From April 1989 to July 1991, 72 patients with residual or recurrent nasopharyngeal carcinoma (NPC) were treated by MSH Ir-192 brachytherapy or combined external radiation therapy. All were proven histologically. 39 patients with residual disease and 6 with recurrent lesion at the primary site were identified after one or more courses of radical external radiation. Eleven patients had received brachytherapy for boost therapy after one or more courses of external radiation. Sixteen were treated with a planned protocol of external irradiation combined with intracavitary brachytherapy. The overall local control rate was 93.3%; the local control rate for residual and recurrent disease was 100% and 50%, respectively. Soft palate perforation was observed in 3 patients. Brachytherapy is believed to be a useful treatment for residual or recurrent NPC following radical external radiation.

[Pulmonary lymphangiomyomatosis: report of a case]

A case of pulmonary lymphangiomyomatosis in a 28-year-old woman with dyspnea, hemoptysis, chylothorax and irregular menstruation as presenting symptoms was reported. Chest CT scan showed the presence of pleural effusion on right side and a honeycomb pattern throughout the lung parenchyma bilaterally. The diagnosis was confirmed histologically by transbronchial lung biopsy. Medroxyprogesterone was administered; improvement in arterial blood gas analysis and reduction of the amount of pleural effusion were noted after one month. The etiology, clinical manifestations, pathological characteristics and treatment of this disease were discussed.

Effects of argipressin injected into medial amygdaloid body on blood pressure and heart rate in rats

Graded injections of argipressin (Arg, 150, 300, and 600 ng/1.5 microliters CSF, 2 min) into the medial amygdaloid body in anesthetized rats produced a dose-related increase in the mean arterial pressure and heart rate (Maximal delta MAP = 2.9 +/- 1.5 kPa, Maximal delta HR = 67 +/- 38 bpm), which lasting > 40 min at 600 ng dosage. Naloxone (15 micrograms/15 microliters CSF) injected into the lateral ventricle blocked the cardiovascular responses to Arg. These results suggest that Arg exerts a central action on the cardiovascular system via the opioid in the lateral ventricle.

Structure of the rat insulin-like growth factor binding protein-4 gene

A family of six distinct insulin-like growth factor binding proteins (IGFBPs) have been isolated and their cDNA sequences characterized from rat and human species. Recently, the gene structures of the first three IGFBPs (IGFBP-1, -2 and -3) have also been determined. We now report the isolation of the rat IGFBP-4 gene and its genomic organization, as well as the DNA sequence of the promoter region. Rat IGFBP-4 gene spans at least 12 kilobases (kb) of the genomic sequence. It consists of four exons separated by three introns with approximate size of 6.4, 0.6 and 2.7 kb. A single transcriptional start site is located at 249 nucleotides upstream of the translational initiation ATG codon. The rat IGFBP-4 gene possesses a typical TATA box and a CAAT box, as well as multiple potential cis elements, including three cAMP responsive elements, three AP-1 binding sites and one progesterone receptor binding site in the 5' flanking region. The presence of these potential cis elements supports the tissue-specific expression of the IGFBP-4 gene.

Direct in vivo gene transfer to airway epithelium employing adenovirus-polylysine-DNA complexes

Adenovirus-polylysine-DNA complexes were evaluated for their capacity to accomplish direct in vivo gene transfer to airway epithelium employing a rodent model. Binary complexes containing transferrin or adenovirus, or combination complexes containing both transferrin and adenovirus, were evaluated. The highest in vitro gene transfer efficiency in primary cultures of airway epithelial cells was accomplished by the combination complexes. This result was paralleled in vivo. Transient gene expression of up to 1 week was observed with localization of the transduced cells to the region of the small airways. These results establish the feasibility of this type of approach for gene therapy applications.

Dosimetry in photodynamic therapy: oxygen and the critical importance of capillary density

Recently published results of tumor response to various photoradiation protocols in photodynamic therapy appear to contradict accepted definitions of photodynamic dose. In this report, the failure of standard dosimetry models to predict therapeutic outcome is interpreted on the basis of PDT-induced oxygen consumption in tumors with relatively low capillary densities. Calculated estimates of oxygen consumption in photodynamic therapy are combined with the Krogh cylinder model of oxygen diffusion. It is shown that, for tissue volumes in which the intercapillary spacing is less than a specific critical distance, oxygen may be considered constant and unaffected by the therapy. Under these conditions, the 1O2 delivered to a given volume of tissue is spatially uniform and proportional to the number of photons absorbed by the sensitizer. When the intercapillary spacing exceeds the critical distance, the dose of 1O2 varies with radial distance from the capillary wall. In this situation, dose may no longer be considered simply in terms of the product of the photon fluence and the sensitizer absorption coefficient. Since fractionation will increase the 1O2 dose only to cells relatively remote from the capillary wall, the analysis further suggests that fractionating the radiation dose should result in an improved therapeutic ratio for photodynamic therapy.

[Chemical constituents of the leaves of Acanthopanax trifoliatus (Linn) Merr]

Nevadensin (A), kaur-16-en-19-oic acid (B), taraxerol (C) and taraxerol-acetate (D) were isolated from the leaves of Acanthopanax trifoliatus. A and B were isolated for the first time. Pharmacological experiments have shown that nevadensin possesses expectorant and antitussive actions.

Repression of the embryonic myosin heavy chain phenotype in regenerating chicken slow muscle is dependent on innervation

Ventricular-like and fast myosin heavy chains (VL-MHC and FMHC) are transiently expressed during slow skeletal muscle development. The influence of innervation on repression of these MHC isoforms is investigated over an 84-day time course in: (1) normal anterior latissimus dorsi (N-ALD) muscles, (2) regenerating ALD (R-ALD) muscles, (3) denervated ALD (D-ALD) muscles, and (4) regenerating and denervated ALD (RD-ALD) muscles. Western blotting demonstrates that the VL-MHC is expressed in R-, D-, and RD-ALD muscles, but not in N-ALD muscles. Expression of the VL-MHC is transient in R-ALD muscles. In contrast, VL-MHC expression persists in RD-ALD muscles, and appears with time in D-ALD muscles. FMHC was not detected in N-ALD muscles by Western blotting. Two FMHCs are seen in R-ALD and RD-ALD muscles, and in 13-day embryonic ALD muscles. The slower migrating FMHC (FMHCA) comigrates with developmentally regulated FMHCs in fast pectoralis muscle, while the faster migrating FMHC (FMHCB) comigrates with the faster migrating FMHC in embryonic ALD muscle (13 days in ovo). FMHCB decreases in amount over the time course in R-ALD muscles, while FMHCA persists. In contrast, substantial levels of both FMHCs persist in RD-ALD muscles, and appear with time in D-ALD muscles. The cellular distribution of MHCs is followed by immunocytochemistry. Regenerating cells expressing VL-MHC and FMHC are replaced by a mature population in R-ALD muscles. Some of the mature myofibers in R-ALD muscles express FMHC, but not VL-MHC. In RD-ALD and D-ALD muscles, both regenerating and mature muscle cells are seen which express VL-MHC and FMHC. Our results indicate that innervation is required for the repression of VL-MHC and FMHCB during regeneration of slow muscle.

[Relation between emphysema and diaphragmatic fatigue]

Emphysematous rats induced by elastase were divided into 5 groups: N (control), P1 (elastase for 3 mo.), P2 (elastase for 4.5 mo.; NS intraperitoneally for 1 mo. after 3.5 mo. elastase); A and C, aminophylline and ginseng preparation were respectively given in the same fashion as P2. The results were: 1. tension and endurance of diaphragm muscle decreased under low frequency stimulation in P2, while those no change in P1. DNA, RNA and ATPase increased, cross-sectional areas and glycogen decreased in P1, while ATPase and RNA reduced with increase of cross-sectional areas in P2; 2. in A, no change in tension, with enhanced endurance; 3. in C, tension increased with no change in endurance; 4. glycogen and cross-sectional areas increased in both A and C; 5. RNA and ATPase increased in C and no change in A.

Effect of fathers' age and birth order on occurrence of congenital heart disease

STUDY OBJECTIVE

The aim was to examine if there is an effect of fathers' age and of birth order on the occurrence of congenital heart disease.

DESIGN

This was a hospital based case-referent study including use of birth defects surveillance data.

SUBJECTS

Subjects were 497 cases of congenital heart disease aged between 3 months and 5 years, born in Beijing and Hebei Province, China; 6222 children without congenital heart disease serve as reference baseline.

MEASUREMENTS AND MAIN RESULTS

With stratified analysis and logistic regression analyses, congenital heart disease was found to be associated with fathers' age less than 25 years (odds ratio 2.63), independent of mothers' age and of birth order. There was also evidence to show a higher birth order effect on the occurrence of congenital heart disease independent of parental ages.

CONCLUSION

Higher birth order and fathers aged less than 25 years were both independently associated with some categories of congenital heart disease and with congenital heart disease overall.

Isolation and molecular cloning of insulin-like growth factor-binding protein-6

Insulin-like growth factors (IGFs) together with their binding proteins (BPs) are potential regulators of folliculogenesis in mammalian ovary. To identify the various species of IGFBPs present in the ovary, we have undertaken a comprehensive purification scheme using gel filtration, ligand-affinity chromatography, and several steps of reverse phase HPLC to isolate all of the BPs in pig ovarian follicular fluid. Our effort yielded five distinct IGFBPs, and upon analysis, they were found to correspond to the previously identified human and rat IGFBP-2, -3, -4, -5, and -6. IGFBP-1 was not found in the pig ovarian follicular fluid under our experimental procedure. Of the six known classes of IGFBPs, the complete primary structures of the first five have been determined, but not IGFBP-6. Using amino acid sequence information from a tryptic fragment of pig IGFBP-6 to prepare a probe, cDNA clones encoding rat and human IGFBP-6 have been isolated and characterized. The deduced amino acid sequence revealed that rat IGFBP-6 contains 201 amino acids with a calculated mol wt of 21,461, while the human homolog contains 216 amino acids with a calculated mol wt of 22,847. In addition, a distinctive feature of human and rat IGFBP-6 is that they lack, respectively, two and four of the 18 homologous cysteines that are present in all other five IGFBPs. The missing cysteines in IGFBP-6 resulted in the absence of the invariant Gly-Cys-Gly-Cys-Cys sequence in the amino-terminal region of the molecule. Human IGFBP-6 possesses a single Asn-linked glycosylation site near the carboxyl-terminal, whereas no potential Asn-linked glycosylation sites are present in the rat sequence. A single 1.3-kilobase IGFBP-6 mRNA was detected by Northern analysis in all rat tissues examined, including testis, intestine, adrenal, kidney, stomach, spleen, heart, lung, brain, and liver, indicating that this BP is a ubiquitous protein. The chromosome location of the IGFBP-6 gene in human has been determined using polymerase chain reaction on somatic cell hybrid DNAs of human and hamster, and the results showed that it is located on chromosome 12.