Glans sculpting in phalloplasty--experiences in female-to-male transsexuals

An aesthetically appealing neophallus with an urethral meatus at its tip is one of the goals of phalloplasty in female-to-male transsexuals. From July 1993 to December 1996, 20 cases of female-to-male transsexuals who had received sculpting of glans in four different ways were enrolled. Their photographs were collected and were scored by independent surgical and non-surgical assessors. The Norfolk procedure creates a more normal neoglans assessed by patients themselves and by the assessors. Split-thickness skin graft (SSG) produces a more normal-looking coronal sulcus than full-thickness skin graft (FTSG) in the Norfolk procedure.

[Preserving remnant liver function after major hepatic vein occlusion]

OBJECTIVE

To observe the pathological changes of the remained hepatic lobe after major hepatic vein (MHV) occlusion.

METHOD

Seventy-eight rats were randomly divided into the control group, the ligation group of segmental hepatic vein, the stricture group of left MHV, and the ligation group of left MHV. The pathology, hepatic microcirculation and hemodynamic changes of the involved hepatic lobe of MHV occlusion were dynamically determined.

RESULT

Necrosis occurred in the hepatocytes at the first postoperative day in the ligation group of MHV. Extensive collaterals between the hepatic veins and the portal veins appeared in the periphery of involved liver lobe in the stricture group of MHV. The levels of endotoxin and TXB(2)/6-Keto-PGF1alpha in the blood of portal vein obviously increased in the ligation group of MHV and also increased in the stricture group of MHV. The levels of endotoxin and TXB(2)/6-Keto-PGF1alpha in the blood of portal vein in the ligation and stricture group of MHV were apparently higher than those in the ligation group of segmental hepatic vein and in the control group.

CONCLUSION

The involved liver tissue can not tolerate complete MHV occlusion. The hepatic tissue lacking of MHV drain not only loss its function, but also cause endotoxemia and disorder of hepatic microcirculation. The involved hepatic lobe after the MHV ligation should have been resected at the same time.

[The significance of point-inflection at static pressure-volume curve in optimal PEEP at early stage of ARDS in sheep]

OBJECTIVE

To study the optimal level of PEEP at early stage of ARDS.

METHOD

The parameters of hemodynamics, lung mechanics, and gas exchange were compared at different levels of PEEP, including maximal static compliance PEEP, point-inflection PEEP, 3 cmH2O higher or lower than point-inflection PEEP, and zero end-expiratory pressure.

RESULTS

Point-inflection PEEP (6.8 +/- 1.4 cmH2O) was significantly lower than maximal static compliance PEEP (9.3 +/- 1.4 cmH2O), P < 0.01. The hemodynamic parameters were not significantly different in point-inflection PEEP compared with 0cmH2O-PEEP (P > 0.05), but oxygenation index (PaO2/FiO2) and lung mechanics (static compliance and airway resistance) were improved significantly at point-inflection PEEP (P < 0.01). At maximal static compliance PEEP or 3 cmH2O higher than point-inflection PEEP, the hemodynamic parameters and PaO2/FiO2 were not different from those at point-inflection PEEP (P > 0.05). The pulmonary vascular resistance index (PVRI) was significantly higher (P < 0.05) and the mean airway pressure and peak inspiratory pressure increased significantly (P < 0.01).

CONCLUSION

In the treatment of early ARDS, the PEEP needed may be lower than the "optimal PEEP" determined by obtaining the maximal static compliance. The application of point-inflection PEEP determined at inspiratory static pressure-volume curve was appropriate as the best PEEP.

[Detection of SMN gene deletions in spinal muscular atrophy]

OBJECTIVE

Survival motor neuron gene(SMN) and neuronal apoptosis inhibitory protein gene (NAIP) have been identified as the candidates of progressive spinal muscular atrophy (SMA)-determining genes. The aims of this study were to investigate the absence of SMN gene exon 7 in Chinese SMA patients, to confirm the relationship between the deletion of the SMN and SMA further, and to establish methods for gene diagnosis and prenatal diagnosis of SMA.

METHODS

PCR-SSCP with silver staining method was used to detect the genomic DNA of 37 SMA patients and 30 normal individuals for deletions of SMN exon 7.

RESULTS

Homozygous deletion of the SMN exon 7 was identified in 86.7%(13/15) of type I SMA patients and 86.4%(19/22) of type II patients. In the 88 controls (including parents of patients and normal individuals), homozygous absence of SMA exon 7 was only found in a mother of a patient.

CONCLUSION

The data support that homozygous absence of SMN exon 7 is strongly associated with SMA. The percentage of homozygous deletions in this study is almost as high as that reported by other researchers. This method is useful, reliable and effective for gene diagnosis and prenatal diagnosis of SMA.

Local interaction fields and adaptive regularizers for surface reconstruction and image relaxation

A set of novel local interaction fields associated with input point data and adaptive regularizers are introduced for some problems in image processing and early-middle vision. The local interaction field is used to take the place of the delta-error term in conventional approaches. It consists of two parts; one is the usual error term, the other is a window function whose shape, size and orientation can be adapted to local structures in specific applications. Unlike the usual delta-error term, local interaction fields favour local flatness and thus impose smoothing implicitly. Several adaptive regularizers are introduced to keep discontinuities while smoothing. In finding solutions, even the simplest gradient descent algorithm is efficient in many examples. The results are stable under varying parameters and quite robust against noise.

[Clinical study of physiologic work of breathing as a weaning parameter in mechanically ventilated patients]

OBJECTIVE

To evaluate the physiologic work of breathing (WOBphy) as a predicting Parameter of weaning and extubation.

METHODS

WOBphy was obtained by the patient's work of breathing (WOBt), minuting the imposed work of breathing (WOBimp). In weaning trial, if the patients could not meet predefined extubation criteria, but WOBphy < 0.70 J/L, the patients were also extubated immediately.

RESULTS

In a group of 28 patients who met the predefined criteria (group 1), 27 patients were successfully extubated. In another group of 13 patients who could not meet the criteria, but WOBphy < 0.70 J/L (group 2), extubation was successful in 12 patients. WOBt and WOBimp were significantly higher in group 2 (1.37 +/- 0.50 and 0.82 +/- 0.37 J/L) than group 1 (0.96 +/- 0.38 and 0.55 +/- 0.27 J/L, P < 0.05), while WOBphy was higher in group 2, but did not reach statistical significance.

CONCLUSIONS

WOBphy < 0.70 J/L may be safe as the weaning and extubation criterion and enables earlier extubation.

Phosphorylation-independent activity of the response regulators AlgB and AlgR in promoting alginate biosynthesis in mucoid Pseudomonas aeruginosa

Overproduction of the capsular polysaccharide alginate appears to confer a selective advantage for Pseudomonas aeruginosa in the lungs of cystic fibrosis patients. The regulators AlgB and AlgR, which are both required as positive activators in alginate overproduction, have homology with the regulator class of two-component environmental responsive proteins which coordinate gene expression through signal transduction mechanisms. Signal transduction in this class of proteins generally occurs via autophosphorylation of the sensor kinase protein and phosphotransfer from the sensor to a conserved aspartate residue, which is present in the amino terminus of the response regulator. Recently, kinB was identified downstream of algB and was shown to encode the cognate histidine protein kinase that efficiently phosphorylates AlgB. However, we show here that a null mutation in kinB in a mucoid cystic fibrosis isolate, P. aeruginosa FRD1, did not block alginate production. The role of the conserved aspartate residue in the phosphorylation of AlgB was examined. The predicted phosphorylation site of AlgB (D59) was mutated to asparagine (N), and a derivative of an AlgB lacking the entire amino-terminal phosphorylation domain (AlgB delta1-145) was constructed. A hexahistidine tag was included at the amino terminus of the wild-type (H-AlgB), H-AlgB delta1-145, and mutant (H-AlgB.59N) AlgB proteins. These derivatives were purified by Ni2+ affinity chromatography and examined for in vitro phosphorylation by the purified sensor kinase protein, KinB. The results indicated that while KinB efficiently phosphorylated H-AlgB, no phosphorylation of H-AlgB delta1-145 or H-AlgB.D59N was apparent. An allelic exchange system was developed to transfer mutant algB alleles onto the chromosome of a P. aeruginosa algB mutant to examine the effect on alginate production. Despite the defect in AlgB phosphorylation, P. aeruginosa strains expressing AlgB.D59N or H-AlgB delta1-145 remained mucoid. The roles of the conserved aspartate residues in the phosphorylation of AlgR were also examined. As seen with AlgB, mutations in the predicted phosphorylation site of AlgR (AlgR.D54N and AlgR.D85N) did not affect alginate production. These results indicate that in vivo phosphorylation of AlgB and AlgR are not required for their roles in alginate production. Thus, the mechanism by which these response regulators activate alginate genes in mucoid P. aeruginosa appears not to be mediated by conventional phosphorylation-dependent signal transduction.

Research on the schizont cell culture vaccine against Theileria annulata infection in Xinjiang, China

Theileria annulata infection (TAI) is one of the most serious diseases of cattle in Xinjiang Autonomous Region of Uigur Minority Nationality. It has been recorded in 14 prefectures, except the Tulufan Prefecture, but the enzootic areas are mainly distributed around the Zhunger Basin and Talim Basin. According to the records collected in the ten years before vaccination with the schizont cell culture vaccine was carried out, the average incidence rate of TAI in enzootic areas was 7.22% and the mortality rate was 24%. The milk production of cattle suffering from TAI was sharply decreased, and there were usually abortions in pregnant cows. The incidence rate and mortality rate were greater in high grade cattle, so TAI was a constraint to improving cattle breeds. To control this disease effectively in Xinjiang, researchers at the Xinjiang Academy of Animal Science began to study the schizont cell culture vaccine in 1972. In 1977 an immortalised cell line was achieved from a primary cell culture starting with white blood cells from cattle suffering from acute TAI caused by an artificial tick bite. The cell culture medium mainly consisted of calf serum, lactalbumin-hydrolysate, Eagles' medium DMEM and three antibiotics. As a vaccine, the above cells were mixed with preserving medium containing gelatin. This paper describes the experiments on the immunological properties of the vaccine carried out in subsequent years. Up to 1996, vaccine doses for 1,186,150 cattle have been produced and sold. This vaccine has had a critical effect on the control of TAI in Xinjiang. Owing to the sharp decrease in the incidence rate and mortality rate of TAI after cattle were vaccinated, the annual economic benefit of the vaccine is at least 1,620,000 yuan.

[Carcinoma metastatic to the cervix: a study of 19 cases]

OBJECTIVES

To report the clinical features and to evaluate the treatment results of 19 cases of cervical metastatic carcinoma.

METHODS

We analyzed retrospectively the 19 patients with carcinoma metastatic to the cervix treated during the period of 1959 to 1994 at Cancer Hospital, Chinese Academy of Medical Sciences.

RESULTS

The average age of patients was 43.7. The main symptom was irregular vaginal discharge and (or) bleeding. In most patients, the primary cancers originated from digestive tract or ovary. The treatment methods included radiotherapy alone, radiotherapy combined with chemotherapy after operation, and surgery plus radiotherapy. The 1-, 2- and 5-years survival rates (life-time table were 68.5%, 47.3% and 26.2% respectively, and the longest period for survived patient with dysgerminoma has lived was more than 22 years.

CONCLUSION

The active proper treatment of primary cancer can prolong the survival time of patients with carcinoma metastatic to the cervix. The patients whose metastatic lesions are limited to the cervix and sensitive to the radiation may be cured by radiotherapy and combination therapy.

Genetic construction and characterization of an anti-monkey CD3 single-chain immunotoxin with a truncated diphtheria toxin

We have previously developed a chemically conjugated anti-rhesus monkey CD3 immunotoxin FN18-CRM9 that can deplete in vivo T cells and induce long term tolerance of mismatched renal allograft in rhesus monkeys. This immunotoxin is a monkey analogue of anti-human CD3 immunotoxin UCHT1-CRM9. In this study, we cloned the light and heavy chain variable regions of anti-monkey CD3 monoclonal antibody FN18 and constructed a single-chain Fv (sFv) by linking variable light and variable heavy regions with a (Gly4Ser)3 linker. The single-chain immunotoxin DT390-FN18sFv was constructed by ligating the sFv to the carboxyl terminus of DT390, a truncated form of diphtheria toxin. The DT390-FN18sFv fusion protein was expressed in Escherichia coli and purified with Ni-RTA affinity and anion exchange columns. Similar to the chemically conjugated immunotoxin FN18-CRM9, DT390-FN18sFv can also specifically inhibit protein synthesis in primary monkey T cells in a dose-dependent manner. DT390-FN18sFv at 10(-7) mol/L or FN18-CRM9 at 10(-8) mol/L is sufficient to reduce protein synthesis of monkey primary T cells to less than 5% of the control. The 50% inhibition dosage (IC50) of FN18-CRM9 is 1 x 10(-10) mol/L, while the IC50 of DT390-FN18sFv is 1 x 10(-8) mol/ L, reflecting the lowered affinity of monovalent Fab' FN18 to its parental divalent antibody. The availability of functional FN18sFv will provide the basis for the construction of divalent anti-CD3 immunotoxins for preclinical studies on the induction of tolerance in organ transplantation and experimental autoimmune diseases.

Antiganglioside antibodies in cerebrospinal fluid of children with neuropsychiatric lupus erythematosus

OBJECTIVE

To determine antiganglioside antibodies (AGA) in cerebrospinal fluid (CSF) of children with neuropsychiatric lupus erythematosus (NPLE), and to investigate their association with clinical manifestations and other laboratory tests.

METHODS

An enzyme linked immunoabsorbent assay was used to detect AGA in 22 CSF samples obtained from 18 children with systemic lupus erythematosus (SLE). These patients were further classified into clinical active NPLE (9 patients) and SLE (9 patients) groups. Indirect immunofluorescent assay was used for determination of CSF antinucleus antibodies (ANA).

RESULTS

AGA could be found in CSF of all the 9 active NPLE children who had neuropsychiatric manifestations within 6 months before or after AGA was tested. A clear association was observed between AGA and brain CT scan. No detectable ANA was found in CSF samples even though high titer of ANA was present in corresponding serum samples of SLE patients.

CONCLUSION

Detection of AGAs in CSF, more sensitive and specific than routine CSF examination and EEG, and positively associated with brain CT scan, is a simple and practical test for early judgment of childhood NPLE.

[Effects of yizhi pills on memory, superoxide dismutase and malondialdehyde of brain and immunity in mice]

Passive avoidance tests have shown that Yizhi Pills (YZ) markedly improve the memory of normal mice at a dose of 100 mg/kg after oral administration for fifteen days, and significantly reverse the scopolamine, NaNO2 and EtOH-induced disruptions of memory retention in mice at doses of 100, 200, 500 mg/kg after oral administration for five days. In aged mice induced by D-galactose, YZ also significantly improve the impaired memory, increase the activity of SOD and decrease the content of MDA in brain. All these effects were observed at doses of 200, 500 mg/kg after oral administration for forty-one days. YZ significantly promote blood carbon particle clearance, enhance hemolysin antibody in immunodepressed mice induced by cyclophosphamide, and increase earswelling in immunodepressed mice induced by prednisolonum.

Identification of the histidine protein kinase KinB in Pseudomonas aeruginosa and its phosphorylation of the alginate regulator algB

The exopolysaccharide alginate is an important virulence factor in chronic lung infections caused by the bacterium Pseudomonas aeruginosa. Two positive activators for alginate synthesis, algB and algR, are members of a superfamily of response regulators of the two-component regulatory system. AlgB belongs to the NtrC subfamily of response regulators and is required for high-level production of alginate. In this study, an open reading frame encoding a polypeptide of 66 kDa, designated kinB, was identified immediately downstream of algB. The sequence of KinB is homologous to the histidine protein kinase members of two-component regulatory systems. Western blot analysis of a P. aeruginosa strain carrying a kinB-lacZ protein fusion and studies of kinB-phoA fusions indicate that KinB localizes to the inner membrane and has a NH2-terminal periplasmic domain. A KinB derivative containing the COOH terminus of KinB was generated and purified. In the presence of [gamma-32P]ATP, the purified COOH-terminal KinB protein was observed to undergo progressive autophosphorylation in vitro. Moreover, the phosphoryl label of KinB could be rapidly transferred to purified AlgB. Substitutions of the residues conserved among histidine protein kinases abolished KinB autophosphorylation. These results provide evidence that kinB encodes the AlgB cognate histidine protein kinase.

[Preoperative intraperitoneal versus intravenous carboplatin chemotherapy for advanced gastric cancer, pharmacokinetics and drug accumulation study]

OBJECTIVE

To examine the accumulation of anticancer drugs in tumor tissues by different routes of administration.

METHODS

Pharmacokinetic comparison of preoperative intraperitoneal (i.p.) and intravenous (i.v.) carboplatin chemotherapy was done in 10 patients each with advanced, resectable gastric cancer. Preoperatively, 300 mg/m2 carboplatin in 750 ml 0.9% sodium chloride was administered by i.p. or i.v. At 160-180 minutes after drug administration, peritoneal fluid, portal vein blood and peripheral blood were taken. At 240-270 minutes later, cancer tissues, peritumor normal tissues, omentum majus, peritoneum and cancer-free lymph nodes were collected during operation. Total carboplatin concentrations were measured by high performance liquid chromatography (HPLC).

RESULTS

High concentrations of carboplatin were found in all tissues by i.p. administration. Drug concentration was highest in the peritonaeum, being 4 times as high as that after i.v. administration. Cancer tissue had higher drug concentration than did peritumor normal tissues. Compared to those after i.v. administration, concentrations in the peritoneal fluid, portal vein blood and peripheral blood were 13, 3 and 1.5 times as high, respectively. No significant differences were observed in drug concentrations in the peritoneum, omentum majus and lymph nodes after i.v. administration.

CONCLUSION

For gastric cancer, carboplatin chemotherapy by i.p. administration is a better route for clinical practice.

Capillary zone electrophoresis at subzero temperatures II: chiral separation of biogenic amines

The separation of enantiomer pairs of eight biogenic amines by capillary zone electrophoresis (CZE) was investigated with heptakis (2,6-di-O-methyl)-beta-cyclodextrin as the chiral selector at temperatures ranging from -20 degrees to 40 degrees C by using a commercial electrophoresis unit retrofitted with an external thermostated refrigerated circulating bath in order to assist the original cooling system. Sodium phosphate in both neat aqueous and methanolic media at pH 2.5, as measured by the glass pH electrode, were used with the fused silica capillary from 1.5 degrees to 40 degrees C and -20 degrees to 40 degrees C, respectively. The effect of temperature on enantioselectivity was found to depend on the number of phenolic hydroxyl groups in the molecule. Upon lowering the temperature from 40 degrees to -20 degrees C, the chiral selectivity of the system, as measured by the relative mobility difference, increased tenfold for the amines with two vicinal phenolic hydroxyls, whereas the increase was insignificant for those having no phenolic hydroxyl groups. The complex formation constants of three amines which have the same molecular structure but the number of phenolic hydroxyl groups were determined at different temperatures and the thermodynamic parameters as well as compensation temperatures for the process were evaluated. Whereas the compensation temperature was 690 K for the amine without phenolic hydroxyl group, it was < 400 K for the amines with one or two phenolic hydroxyl groups. The difference in the compensation temperatures indicates that the intrinsic mechanisms of their complexation with the chiral selector are not the same; this may account for the discrepancies observed in the temperature dependency of the chiral selectivity. The enthalpy change per phenolic hydroxyl group was 2.5 kcal mol(-1), which compares favorably with the typical value for a single hydrogen bond. Therefore, when the amines have phenolic hydroxyl groups, the strong increase in chiral selectivity with decreasing temperature may be due to enhanced H-bonding between the cyclodextrin and the phenolic hydroxyls under the conditions employed in this study.

Tumor necrosis factor-alpha and interleukin-1 induce activation of MAP kinase and SAP kinase in human neuroma fibroblasts

Two cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1), which are released by macrophages during the early inflammatory phase of nerve injury, are known to induce activation of mitogen-activated protein kinase (MAPK) and stress-activated protein kinase (SAPK), which locate at different signal transduction pathways and are involved in cell cycle G0/G1 transition and cellular proliferation in human fibroblasts. Activation of these two protein kinases by the cytokines may stimulate fibroblast proliferation in damaged nerves and thereby play a role in the formation of a neuroma, a disorganized mass of tissue that interferes with neural regeneration and repair. To investigate the possibility that this mechanism is operative in neuroma formation, we used cultured, serum-starved fibroblasts from surgically removed human neuromas stimulated with TNF-alpha and/or IL-1 alpha and IL-1 beta, and measured the activation of MAPK and SAPK using myelin basic protein (MBP) and human c-Jun (1-169) glutathione S-agarose transferase (GST) fusion protein as substrates. For comparison, neuroma fibroblast cultures were also stimulated with phorbol 12-myristate 13-acetate (PMA) and platelet-derived growth factor-AB (PDGF-AB), a potent activator for MAPK. TNF-alpha and both forms of IL-1 produced a rapid activation of MAPK, with a peak at 15 min for TNF-alpha stimulation, and a peak at 30 min for IL-1 stimulation. TNF-alpha combined with either IL-1 alpha or IL-1 beta produced a synergistic effect on the activation of MAPK. The increases in MAPK induced by TNF-alpha and IL-1 were similar to the increases induced by PMA and PDGF-AB. To confirm the presence of MAPK, immunoprecipitation and immunoblotting were carried out on experimental and control lysates. TNF-alpha and IL-1 also increased activation of SAPK, but to a lesser extent than MAPK. PMA and PDGF-AB were also much less effective in stimulating activation of SAPK. Our findings indicate that TNF-alpha and IL-1 activate parallel signal transduction pathways in human neuroma fibroblasts, and that they are relatively stronger activators of MAPK than of SAPK. Previous studies have convincingly demonstrated that MAPK and SAPK are involved in human fibroblast proliferation. The results of our study suggest that TNF-alpha and IL-1 may play a role in frustrating functional nerve regeneration after injury by stimulating these two kinases, which, in turn, leads to fibroblast proliferation and formation of neuromas.

Investigation of effects of pregnant mare serum gonadotropin (PMSG) on the chromosomal complement of CD-1 mouse embryos

PURPOSE

The objective of this study was to examine the effect of superovulatory doses of gonadotropins on the frequency of chromosomal abnormalities of mouse embryos.

METHODS

Chromosome analysis of 8- to 16-cell stage mouse embryos and zygotes was performed by a cytogenetic method.

RESULTS

There was no significant effect of the pregnant mare serum gonadotropin (PMSG) dose on the level of aneuploidy and structural abnormalities from 8- to 16-cell-stage embryos among superovulated groups. However, a simple dose-response relationship between the PMSG dose and the incidence of polyploidy was observed, with the level of polyploidy rising from 2.9% with 10 i.u. PMSG to 10.5% with 15 i.u. PMSG. In zygote stage, the proportion of polyploid embryos also increased as the dose increased, from 1.9% in 5 i.u. to 6.7% in 15 i.u. PMSG. It was observed that the extra chromosomal set in polyploidy embryos originated by both fertilization of a diploid oocyte and dispermy.

CONCLUSIONS

These results indicate a dose-response relationship between the PMSG dose and the incidence of polyploidy in the CD-1 mouse. Both a disturbance at maturation division and an error at fertilization were the cause of polyploidy.

Role for insulin-like growth factor I in the regulation of electrolyte composition of uterine luminal fluid

A potential role for insulin-like growth factor I (IGF-I) in the regulation of the uterine electrolyte environment was studied in conjunction with hyperoestrogenaemia caused by superovulation. Uterine luminal fluid from immature rats treated with 4 (control), 10, 20 and 40 i.u. (superovulation) pregnant mares' serum gonadotrophin (PMSG, day -2) and the electrolyte composition was determined on day 3 of pregnancy. Superovulation increased total cation content in uterine flushes by more than twofold, suggesting a comparable increase in the uterine luminal fluid volume. Percentages of K+ and HCO-3 content to total cations or anions increased by 27% and 16%, respectively, and those of Na+ and Cl- decreased by 26% and 15%, respectively, after superovulation. Daily injections with 1.0 micrograms or more oestradiol, from day 0 to day 2, in the 4 i.u. PMSG-primed immature rats caused similar changes in total cation content and electrolyte composition of uterine luminal fluid. Anti-IGF-I antibody infusion in the superovulated or oestradiol-treated immature rats restored the alterations in cation composition but had no effect on anion composition and total cation content. IGF-I was infused into adult rats to achieve increased IGF-I action observed after superovulation. IGF-I infusion altered electrolyte composition, as is observed after superovulation or oestradiol treatment, but had no effect on total cation content. In conclusion, hyperoestrogenaemia caused by superovulation may alter the uterine electrolyte environment for preimplantation embryonic development. IGF-I appears to play a central role in mediating this action of oestrogen.

Structural, functional analysis and localization of the human CAP18 gene

CAP18 is an antimicrobial protein found in specific granules of PMNs. The human CAP18 (HCAP18) gene was cloned from a human genomic phage library. Sequence analysis revealed the HCAP18 gene to have 4 exons spanning 3 kb, including 700 bp of upstream DNA. Using 3' RACE no homologs of human HCAP18 were found in human bone marrow or leukocyte populations. By PCR analysis of a somatic cell mapping panel and fluorescence in situ hybridization of a genomic clone to metaphase chromosomes the gene was mapped to chromosome band 3p21.3. Like several other genes expressed late in PMN development the CAP18 gene did not contain typical TATA box or CCAAT sequences. Expression in Cos 7 cells permitted limited mapping of the promoter function in upstream fragments of the HCAP18 gene. Western blot, Northern blot and RT-PCR analysis show HCAP18 to be produced specifically in granulocytes. This work forms the groundwork for future analysis of the genetic regulation of this antimicrobial protein during PMN differentiation.

Measurement of radiation-induced DNA double-strand breaks in human diploid fibroblasts from keloid and normal skin by single-cell gel electrophoresis

Cell culture experiments recently have shown that different populations of fibroblasts may exist in keloid patients. Moreover, several studies have strongly suggested heterogeneity in cell response of skin fibroblasts in the same individual. The purpose of this study was to evaluate the radiation sensitivity of skin fibroblasts from keloid and normal skin. Single-cell gel electrophoresis was employed in detecting amounts of DNA double-strand breaks generated in individual fibroblasts primarily cultured from normal skin and from keloid tissue after various doses of gamma-irradiation (0, 25, 50, and 100 Gy aerobically) from a 137Cs radiation generator. For the repair study, cells were incubated at 37 degrees C for 0 and 15 minutes and 1 and 2 hours after irradiation. Following neutral lysis and electrophoresis, DNA double-strand breaks were then detected by propidium iodide staining and determined by fluorescence microscope and quantitative image analysis. No significant difference in the extent of DNA double strand breaks in fibroblasts from normal skin or keloid after various doses of irradiation was observed. However, the residual DNA double-strand breaks remaining after various periods of incubation were demonstrated to be significantly increased in fibroblasts from keloid (p < 0.01). In conclusion, different repair capacities were found in fibroblasts from normal skin and keloid scar; this finding may play a role in the treatment of the disease entity.