Fluorine intake of a Tibetan population

Measurements of food consumption of randomly selected families and fluorine levels in food and beverages were used to calculate the fluorine intake of Tibetan people living in nomadic or semi-nomadic areas of the region and regularly consuming brick tea both as a beverage and in food. The fluorine intake of these groups (children 5.49-7.62 mg day; adults 10.43-14.48 mg/day) was much higher than that of members of a Han population living in the region (children 1.44 mg/day; adults 2.54 mg/day). The amounts of fluorine consumed by the Tibetan inhabitants are at least twice the WHO suggested limit (2 mg/day). Tea plants are rich in fluorine, and the highest levels are found in older leaves which are used to make brick tea. We conclude that brick tea is the major source of fluorine intake by the Tibetan population studied.

[Heterogeneity of adrenoceptors in rat basilar and renal arteries]

A comparative study was made on the distribution of alpha- and beta-adrenoceptors between rat basilar (BA) and renal arteries (RA). The results showed that (1) the endothelium-independent relaxation due to beta-agonism was more significant in BA than that in RA; (2) there was no alpha 1-adrenoceptor-mediated vasoconstriction in most of the BA, only a small part of BA showed constriction in response to alpha 1-agonism, but with low affinity and efficacy and a desensitization tendency; (3) no response to alpha 2-agonist BHT 920 (10(-3) mol/L) in BA was shown, either in the presence or absence of endothelium. But in RA there was relaxation in the presence of endothelium and constriction in its absence. The above results suggest that there is a scarce distribution of alpha 1- and alpha 2-adrenoceptors, but an abundant distribution of beta-adrenoceptor in basilar artery compared with that in renal artery. The alpha 1-subtype in BA is different from the alpha 1-subtype in RA, and the alpha 2-receptor which mediates direct smooth muscle constriction and endothelium-dependent relaxation is highly heterogeneous between basilar and renal arteries.

[Mannital induced acute renal failure]

14 cases of mannitol-induced acute renal failure were reported. The dosage of mannitol used varied widely. In all cases serum Na+, HCO3- were decreased, K+ and BUN increased significantly. Serum osmolality was measured in 5 cases. The osmolal gap was increased greatly, 77.4mOsm/kg. H2O in average. The increase of osmolal gap may play an important role in acute renal failure by causing intensive renal vasocontraction. Monitoring of serum osmolality or osmolal gap can help to prevent mannitol intoxication. The decrease of serum Na+ may be a warning sign of increased osmolal gap. Hemodialysis is the best way for the treatment of mannitol-induced acute renal failure.

Quantitative comparison of multiple myeloma tumor contamination in bone marrow harvest and leukapheresis autografts

Autologous transplantation is increasingly being used to treat patients with multiple myeloma (MM). Recently, peripheral blood progenitor cell (PBPC) harvest have been preferred over autologous bone marrow (BM) harvests due to reduced engraftment time, ease of attainment, and presumptive reduction of occult tumor involvement. To resolve this latter assumption quantitatively, we have used the unique immunoglobulin (Ig) heavy chain variable region sequence of the patient's myeloma cell as a marker of clonality. Samples from PBPC collections and 'back-up' BM harvests were obtained from 13 patients with MM and analyzed for tumor contamination using patient-specific oligonucleotide primers and the polymerase chain reaction. As expected, the percentage of tumor cells contaminating the BM harvest (median, 0.74%) was higher than in the PBPC specimens (median, 0.0024%). Because of the increased total number of cells required for PBPC transplantation, the increase in total number of contaminating cells in the BM vs PBPC autografts was less pronounced, (BM:PBPC tumor contamination ratios ranging from 0.9 to > 4500; median, 14). This confirms that in most but not all cases unmanipulated PBPC products are preferable over BM harvests as a method of reducing myeloma autograft tumor contamination.

Human T-cell lymphotropic virus type-I infection in the severe combined immunodeficiency mouse

Human T-cell lymphotropic virus type-I (HTLV-I) is the etiologic agent of HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukemia (ATL). HAM/TSP and ATL occur infrequently among HTLV-I-infected individuals, and rarely develop in the same individual. To study host and viral factors involved in the induction, tissue tropism, as well as pathogenesis of HAM/TSP, peripheral blood lymphocytes (PBL) from 14 patients with HAM/TSP and from 9 controls were introduced into severe combined immunodeficiency (SCID) mice by intraperitoneal injection. Mice were followed for up to 26 weeks. Human IgG was produced from 2 to 14 weeks after reconstitution in all animals. Thirty-two of 44 mice (72%) showed circulating human antibody against the major viral protein products of HTLV-I. Analysis of viral sequences by polymerase chain reaction (PCR) demonstrated HTLV-I sequences in 21/38 (55%) brains and in 7/17 (41%) spinal cords from HTLV-I-hu SCID mice. No animal had clinical evidence of neurological impairment or pathological findings similar to those seen in HAM/TSP. Seven mice who received PBL from Epstein Barr virus (EBV)-seropositive patients developed an intraperitoneal lymphoma. In 2 mice an infiltration of brain by a lymphoblastic tumor of B/T cell type was observed. By PCR, all the tumors were EBV-positive; HTLV-I sequences were detected in 5 of them. Our study suggests that the HTLV-I-hu-SCID mouse provides a potentially valuable system for studying the production, kinetics, and pathogenicity of anti-HTLV-I antibody, and may help clarify the interaction of EBV and retroviruses in the development of disease.

[Heterogeneities in intracellular Ca2+ pools among different arterial smooth muscle cells and its possible role in vascular reactivities in rat]

The differences in intracellular Ca2+ pool capacities, the mutual relations between different agonist-sensitive Ca2+ pools (ASCaP) and between ASCaP and caffeine-sensitive Ca2+ pool (CSCaP), and the possible role of Ca2+ pool capacity in vascular reactivities in different isolated artery rings of rat in Ca(2+)-free media were studied by using the tension of vascular smooth muscle as an indicator of Ca2+ release. The study showed the following findings: (1) the Ca2+ pools were significantly different in capacities in different arteries (renal artery > mesenteric artery > caudal artery > aorta > pulmonary artery); (2) different ASCaPs were partially "overlapped", i.e., when one ASCaP was depleted, other kind of agonist could still induce a small but significant Ca2+ release; (3) the CSCaP was present in all the arteries tested, but it was not the same pool with the ASCaP; (4) there were no high-K+ depolarization-induced Ca2+ release in all the arteries tested and (5) there was a positive correlation between the maximal contraction (Emax expressed as mg force/mg muscle wet weight) and the Ca2+ pool capacities, suggesting that there is a role of Ca2+ pool capacities in the vascular contractilities.

Identification of major and minor chaperone proteins involved in the export of 987P fimbriae

The 987P fimbriae of Escherichia coli consist mainly of the major subunit, FasA, and two minor subunits, FasF and FasG. In addition to the previously characterized outer membrane or usher protein FasD, the FasB, FasC, and FasE proteins are required for fimbriation. To better understand the roles of these minor proteins, their genes were sequenced and the predicted polypeptides were shown to be most similar to periplasmic chaperone proteins of fimbrial systems. Western blot (immunoblot) analysis and immunoprecipitation of various fas mutants with specific antibody probes identified both the subcellular localizations and associations of these minor components. FasB was shown to be a periplasmic chaperone for the major fimbrial subunit, FasA. A novel periplasmic chaperone, FasC, which stabilizes and specifically interacts with the adhesin, FasG, was identified. FasE, a chaperone-like protein, is also located in the periplasm and is required for optimal export of FasG and possibly other subunits. The use of different chaperone proteins for various 987P subunits is a novel observation for fimbrial biogenesis in bacteria. Whether other fimbrial systems use a similar tactic remains to be discovered.

[Clinical results and hemodynamic changes of portal venous system in transjugular intrahepatic portosystemic stent shunt]

To study the clinical results and hemodynamic changes of portal venous system after TIPSS we created a transjugular intrahepatic portosystemic stent shunt in 140 patients with advanced cirrhosis and portal hypertension, meanwhile we used Doppler sonography, direct portography and measurement of portal pressure to assess the blood hemodynamic changes of portal venous system in 100 patients with TIPSS. The technical success rate of TIPSS was 94.62% in 130 patients except for 10 patients with portal venous occlusion. The complication rate related to TIPSS procedure was 4.62%. Slight encephalopathy was observed in 9.03% of patients with TIPSS. The early mortality within 30 days of treatment was 3.08%. Follow-up for 1 to 24 months showed that the stenosis or occlusion of shunt and variceal rebleeding or ascites were observed respectively in 12% and 9% of patients. Six percent of the patients with TIPSS died. The portal venous pressure and the inflow of collateral circulation remarkably decreased and the portal flow velocity increased by 2.4 times after TIPSS. The flow velocity of shunt and portal vein decreased by 11.39% and 20.14% respectively in the patients with shunt patency, while the flow velocity continued to decrease in the patients with shunt stenosis or occlusion during the follow-up. TIPSS is an effective method for treating the patients with portal hypertension due to cirrhosis. The observation of trends in the hemodynamic changes of portal venous and shunt can early diagnose and treat the shunt stenosis or occlusion.

[Clinical trial of an anti-fertility method with testosterone enanthate in normal men]

OBJECTIVE

To establish the feasibility of anti-fertility by ultraphysiological-dosage testosterone in male.

METHODS

Ten healthy, fertile men received 200 mg testosterone enanthate weekly by intramuscular injection based on international standard protocol.

RESULTS

After 3-month injection, severe oligospermia was achieved. After 6-month injection, azoospermia was achieved. The total consecutive administration lasted for 12 months. During the period of severe oligospermia and azoospermia no partner was pregnant. After stopping injection, the sperm output returned to normal (20 x 10(8)/ml) in 2-3 months up to individual's own level before administration in 6 months.

CONCLUSION

Severe oligospermia and azoospermia can be induced by ultra-pathological-dosage tesosterone through inhibiting FSH, LH to cause spermatogenesis inhibition. The sperm output would recover to its previous level in 6 months after stopping injection. It is suggested that there is a strong possibility that high-dosage testosterone may act as a male contraceptive.

Requirement of a corepressor for Dr1-mediated repression of transcription

A Dr1-associated polypeptide (DRAP1) was isolated from HeLa cells and found to function as a corepressor of transcription. Corepressor function requires an interaction between DRAP1 and Dr1. Heterodimer formation was dependent on a histone fold motif present at the amino terminus of both polypeptides. Association of DRAP1 with Dr1 results in higher stability of the Dr1-TBP-TATA motif complex and precluded the entry of TFIIA and/or TFIIB to preinitiation complexes. DRAP1 was found to be expressed in all tissues analyzed with higher levels in tissues with a low mitotic index. Analysis of DRAP1 in the developing brain of rat demonstrated undetectable levels of DRAP1 in actively dividing cells but high levels of DRAP1 expression in differentiated non dividing cells. Dr1 was immunodetected in all cells analyzed. A model for DRAP1-dependent, Dr1-mediated repression of transcription is proposed.

VH gene usage is multiple myeloma: complete absence of the VH4.21 (VH4-34) gene

The immunoglobin heavy chain variable region (VH) gene usage in multiple myeloma (MM) has not been reported, although a few studies have incidentally identified the VH gene rearranged in small cohorts of MM patients. We used a reverse transcriptase-polymerase chain reaction based technique to analyze the VH gene usage in MM. The VH sequences were obtained after amplification of bone marrow cDNA using the seven VH family-specific and constant region primers. The VH sequences of 72 patients were successfully identified. The frequency of VH family usage in decreasing order was VH3>VH4>VH1>VH5>VH2>VH6>VH7 and corresponded to the functional germline complexity of the VH families. Individual VH genes (VH1-69, VH3-9, VH3-23, and VH3-30) were overrepresented in our cohort of MM patients; some VH genes [VH3-49, VH3-53, and VH4.21 (VH4-34)], which are rearranged with increased frequency in normal circulating B cells, autoimmune diseases, and other B-cell malignancies, were not detected in any MM patient. Compared with germline sequences, an average of 8.8% (range, 2.7% to 16.5%) of the nucleotides had evidence of mutation within each VH sequence. Based on these results, we conclude that (1) the VH gene usage in MM is unique compared with other malignant and nonmalignant B-cell populations, (2) the physiologic process of clonal deletion functions to remove clones that have rearranged VH genes (VH4.21) capable of expressing antibodies, which recognize self-antigens, and (3) the complete lack of VH4.21 gene rearrangement may help to partially explain the paucity of autoimmune phenomena in MM.

Dibutyl phthalate purged autologous bone marrow transplant in the treatment of leukemia

It has been proved that di-N-butyl phthalate (DBP) is singular in killing leukemic cells selectively or accelerating the deterioration of residual leukemic cells in long-term marrow culture in vitro. Based on this principle, the DBP-purged autologous bone marrow transplant has been applied to the treatment of a group of 14 patients suffering from acute nonlymphocytic leukemia. After 5-10 days of in vitro co-culture of marrow cells with DBP at a concentration of 50 micrograms/ml, the recovery of total nucleated cells and the amount of CFU-GM were 67.5% and 68.1%, respectively. In all patients, the reconstitution of hematopoiesis was observed after pre-conditioning and transfusion of purged marrow cells. Among these, two patients had a relapse, two patients died from complications of transplant, one patient died from non-leukemic disease, and the others are all alive and free of disease; the mean survival time as calculated recently was 15 months. These preliminary clinical data support that marrow culture in the presence of DBP is a safe and effective measure for treating leukemia in purged autologous bone marrow transplant.

Effect of dietary iron concentration, age, and length of iron feeding on feed intake and tissue iron concentration of broiler chicks for use as a bioassay of supplemental iron sources

Three experiments were conducted with day-old chicks to study the effects of dietary Fe concentration and age on Fe accumulation in tissues as an estimate of supplemental Fe bioavailability, and of delaying the time of initial high Fe supplementation up to 7 d of age on feed intake to 3 wk of age. In Experiment 1, chicks were fed a basal corn-soybean meal diet (188 mg/kg Fe, DM basis) or the basal supplemented with 400, 600, or 800 mg/kg added Fe as reagent grade FeSO4.7H2O for either 1, 2, or 3 wk. Dietary Fe depressed (P < 0.001) feed intake and body weight gain, especially at 3 wk. Kidney Fe concentrations increased linearly (P < 0.001) with increasing dietary Fe. Liver Fe concentration also increased linearly, but reached a plateau in birds fed 600 mg/kg Fe. Bone Fe increased linearly (P < 0.05) at 1 wk, but not at 2 or 3 wk. Liver and kidney Fe regressed on daily Fe intake had the best fit to a linear model at 2 wk. In Experiment 2, chicks were fed either a basal diet (320 mg/kg Fe, DM basis) continuously, the basal supplemented with 800 mg/kg added Fe as FeSO4.7H2O continuously, or were started on the control diet and switched to the high Fe diet on Day 3, 5, or 7. Feed intake was lower (P < 0.05) in birds started on Fe on Days 1 or 3, but delaying feeding of high Fe diets until Day 5 resulted in intake at 3 wk similar to that of birds fed the basal diet. In Experiment 3, the basal diet (123 mg/kg Fe) was fed to chicks for 6 d, then experimental diets were fed for 14 d. Diets were the basal or basal supplemented with 400, 600, or 800 mg/kg added Fe as reagent grade or feed grade Fe sulfate or an Fe methionine complex. When estimated from regression of log10 liver Fe concentration on total analyzed dietary Fe concentration, relative bioavailability was set at 100% for reagent grade Fe sulfate, and the feed grade sulfate was 92.3% and Fe methionine was 88.3%. Liver Fe concentrations may be useful criteria for determining Fe bioavailability and 2 wk of feeding was the optimal time required for such a bioassay. Delaying feeding high Fe diets until 5 d of age alleviated the decreased feed intake associated with high Fe diets.

Identification of RII-binding proteins in the mollusc Mytilus galloprovincialis

Several proteins with M(r) > 70 kDa from various tissues of the sea mussel Mytilus galloprovincialis were specifically recognized in vitro by the regulatory subunit (type RII alpha) of cAMP-dependent protein kinase (cAPK) from porcine heart. However, none of these proteins interacted with the regulatory subunit of cAPK from the mollusc itself. The results suggest that, unlike mammalian RII, regulatory subunit from mussel lacks the specific residues responsible for interaction with R-binding proteins. Consequently, the identified molluscan RII alpha-binding proteins should play a distinct role from cAPK anchoring.

Cataract extraction and intraocular lens implantation with anterior vitrectomy in children

OBJECTIVE

Extracapsular cataract extraction (ECCE) with selective intraocular lens (IOL) implantation has been the choice of the treatment for children with cataracts. With regard to surgical technique, ECCE with anterior segment vitrectomy has shown some success in reducing complications. Formation of a secondary membrane and opacity of the posterior capsule, however, are still major postoperative complications. To reduce these complications, we modified current surgical procedures with minimal incisions and manipulations.

PATIENTS AND METHODS

ECCE with anterior segment vitrectomy was performed using Storz Protage's system in 84 eyes of 58 children ranging in age from 14 months to 14 years. Of 70 eyes of children aged above 3 years, IOLs were implanted simultaneously. Vision improvement and incidence of postoperative complications were compared with other standard procedures to determine the benefits of the operation for children with cataracts. After the anterior capsule was opened by continuous circular capsulorhexis or envelope-form capsulectomy, the lens cortex was excised. Subsequently, the IOL was implanted into the bag.

RESULTS

Nine-30 months follow-up showed that all of the central area of the posterior capsule remained clear except one eye in which a secondary membrane was partially formed on the anterior surface of vitreous. No other operative or postoperative complications occurred.

CONCLUSIONS

The results indicate that the modified procedure is beneficial in the prevention of secondary cataract formation and other postoperative complications in a short term follow-up, however, a long-term follow-up is warranted to evaluate its role in pediatric cataract surgery.

Molecular determinants of acute single-cell lysis by human immunodeficiency virus type 1

Human immunodeficiency virus type 1 (HIV-1) infection of CD4-positive lymphocytes is accompanied by acute cytopathic effects, i.e., syncytium formation and single-cell lysis. Syncytium formation involves cell-cell fusion mediated by viral envelope glycoproteins on the surface of infected cells and by CD4 glycoproteins on adjacent cells. The molecular basis for the lysis of single-HIV-1 infected cells is unclear. Here we report that the expression of functional envelope glycoproteins from primary and laboratory-adapted HIV-1 isolates resulted in the lysis of single CD4-positive lymphocytes. As was previously observed in HIV-1 infected cultures, single-cell lysis in this system primarily involved necrosis and was not inhibited by soluble CD4. Binding of the viral envelope glycoproteins to the CD4 glycoprotein facilitated, but was not sufficient for, cytolysis. Importantly, the ability of the HIV-1 envelope glycoproteins to mediate membrane fusion was essential for single-cell killing. By contrast, the long cytoplasmic tail of the gp41 transmembrane envelope glycoprotein was neither necessary nor sufficient for single-cell lysis. These results suggest that intracellular envelope glycoprotein-CD4 interactions initiate autofusion events that disrupt cell membrane integrity, leading to single-cell lysis by HIV-1.

Chemopreventive effects of green and black tea on pulmonary and hepatic carcinogenesis

The chemopreventive effects of decaffeinated green and black tea treatment on liver and lung tumorigenesis were examined in carcinogen-treated mice. Male C3H mice were given decaffeinated green or decaffeinated black tea in their drinking water prior to, during, and after treatment with diethylnitrosamine (50 micrograms/kg bw, i.p., once per week for 8 weeks). After 40 weeks of tea treatment, mice were sampled and examined for pulmonary and hepatic tumors. Mice treated with both DENA and tea displayed a significant decrease in the mean number of lung and liver tumors compared to DENA-only treated animals. Mice that received 0.63 or 1.25% green tea or 1.25% black tea exhibited a reduction in liver tumor numbers of 54, 50, and 63%, respectively from that seen in the DENA-only treated mice. Tea treatment also significantly decreased the multiplicity of lung adenomas. Mice receiving DENA and either 0.63 or 1.25% green tea or 1.25% black tea showed a decrease in the mean number of lung tumors of 40, 46, and 34%, respectively, from DENA-only treated mice. While a possible association between the chemopreventive activity of tea on lung tumor response and the concentration of (-) epigallocatechin gallate (EGCG) in the tea was suggested, no apparent relationship between EGCG concentration and liver tumor response was seen, however. These results show a dose-dependent chemoprevention of both lung and liver tumors by both black and green tea in diethylnitrosamine-treated C3H mice.

Coding sequence-dependent ribosomal arrest at termination of translation

A remarkably high percentage of proto-oncogene, growth factor, cellular receptor, and viral transcript leaders contain short upstream open reading frames (uORFs), yet the significance and regulatory effects of these uORFs have not been well characterized. In the case of the human cytomegalovirus gpUL4 (gp48) transcript, the second of three uORFs (uORF2) inhibits translation of the downstream cistron by a process that depends on the uORF2 amino acid coding information. To investigate the mechanism underlying this unusual regulatory element, we adapted the toeprinting (or reverse transcriptase extension inhibition) assay for use in detecting positions of ribosomal stalling on gp48 transcripts. Using a cell-free translation system, we demonstrate that ribosomes arrest at the termination codon of uORF2 by a uORF2 coding sequence-dependent mechanism. Further, the sequence requirements for ribosomal stalling are the same as for inhibition of downstream translation. We also provide evidence for ribosomal stalling in vivo, on the natural viral mRNA. These data support the hypothesis that the inhibition of downstream translation results from uORF2 peptide-dependent ribosomal arrest at termination and suggest that translation termination may be a regulatory step in expression of some eukaryotic genes.

Over-expression of HSP-70 protects astrocytes from combined oxygen-glucose deprivation

Pretreatment by a sublethal insult is associated with induction of stress proteins and with protection from subsequent injury. Heat pretreatment protects the brain from subsequent ischemia, and is shown here to protect primary astrocyte cultures from subsequent oxygen-glucose deprivation. To determine whether the expression of a single stress protein, HSP-70, could account for much of this protection, we expressed HSP-70 or beta-galactosidase in astrocytes using retroviral vectors. Only 12% of astrocytes expressing HSP-70 died after 7 hours of oxygen-glucose deprivation compared to 65% of astrocytes expressing beta-galactosidase and 82% of normal astrocytes. Our data provide direct evidence that selective expression of HSP-70 enhances the survival of astrocytes challenged with heat or oxygen-glucose deprivation.

[Penetrating keratoplasty in children]

OBJECTIVE

The study was designed to approach the operative techniques of penetrating keratoplasty (PKP) in children and the influential factors on the rate of graft clarity.

METHODS

PKP was performed on 33 eyes of 30 children whose corneal opacities resulted from various causes and they were followed for 6 months to 3 years.

RESULTS

The rate of graft clarity was 66.7% and 44.8% of these eyes were relieved from blindness. The poorest results achieved were in cases with congenital corneal opacity and the main cause of graft failure is endothelial immune rejection.

CONCLUSION

Although the surgical results in children are poorer than that in adults, from the concern of prevention of amblyopia and cosmetic problem, it is necessary to perform the operation earlier.

[Transjugular intrahepatic portosystemic shunt: indications, prevention and management of complications]

Transjugular intrahepatic portosystemic shunt (TIPS) was carried out in 140 cases of advanced cirrhosis with portal hypertension. The success rate of TIPS was 94.62%. The complication rate of TIPS was 16.15%, of which, 4.62% was TIPS procedure related including intraabdominal or intratheoracic bleeding and rebleeding of esophageal varices. The complication rate related to portosystemic shunt was 11.54% and the complications included encephalopathy and acute hepatic failure. The mortality of TIPS was 3.08% within one month following TIPS. 2.31% of patients died of hepatic failure and 0.77% died of rebleeding of varices.