[Evaluation of transperineal sonography for lower urinary tract symptoms after pelvic floor reconstruction]

Objective: To evaluate transperineal sonography for lower urinary tract symptoms after pelvic floor reconstruction. Methods: Eighty-three patients with severe pelvic organ prolapse received surgeries in Fuzhou General Hospital from September 2014 to September 2015, dividing into two groups: 27 patients were selected to receive transvaginal mesh (TVM) pelvic floor reconstruction surgery with tension-free vaginal tape-Abbrevo (TVT-Abbrevo) incontinence surgery, named TVM+TVT-Abbrevo group; 56 patients were selected to receive TVM pelvic floor reconstruction surgery only, named TVM group. The ultrasonic parameters at rest, on contraction and Valsalva condition respectively were observed and measured, including the bladder neck descent (BND), urethral rotation angle, retrovesical angle, levator urethra gap (LUG), the existence of bladder neck funneling, position of the tape, by using 2D and 3D transperineal ultrasound. Results: The two groups were compared with the ultrasonic parameters before and after operation: two groups of patients with postoperative BND [(2.3±0.5) versus (3.1±0.7) cm, (1.6±0.4) versus (3.6±0.4) cm] were significantly reduced, the difference was statistically significant (P=0.02, P<0.01). The two groups of LUG before and after operation [(3.62±0.45) versus (3.26±0.92) cm, (2.96±0.47) versus (2.72±0.38) cm] both had significant difference by maximum Valsalva (P<0.01, P=0.04). There was statistical significance difference of urethral rotation angle in TVM+TVT-Abbrevo group by maximum Valsalva (P=0.01). Observation of morphology: (1) 2 patients with difficulty in urination in TVM+TVT-Abbrevo group, ultrasound showed when the position of the bladder down the urethra discount; 4 patients with stress urinary incontinence (SUI), ultrasound showed slings off or release. (2) One patient with difficulty in urination in TVM group, but ultrasound showed lower urinary tract anatomy were normal; 5 patients with SUI, ultrasound showed the position of the bladder neck were significantly lower in 3 patients, showing high mobility, and the other 2 patients had a larger urethral diameter, showing a tendency of natural deletion. Conclusion: s Anatomy of lower urinary tract could be clearly showed by transperineal sonography. This could provide imaging support for the diagnosis of lower urinary tract symptoms after pelvic floor reconstruction.

[Distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015: results from a multicenter, retrospective study]

Objective: To describe the distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015 to provide reference for empirical anti-infection treatment. Methods: Pathogens were from hematology department of 26 tertiary hospitals in Jiangsu Province from 2014 to 2015. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or agar dilution method. Collection of drug susceptibility results and corresponding patient data were analyzed. Results: The separated pathogens amounted to 4 306. Gram-negative bacteria accounted for 64.26%, while the proportions of gram-positive bacteria and funguses were 26.99% and 8.75% respectively. Common gram-negative bacteria were Escherichia coli (20.48%) , Klebsiella pneumonia (15.40%) , Pseudomonas aeruginosa (8.50%) , Acinetobacter baumannii (5.04%) and Stenotropho-monas maltophilia (3.41%) respectively. CRE amounted to 123 (6.68%) . Common gram-positive bacteria were Staphylococcus aureus (4.92%) , Staphylococcus hominis (4.88%) and Staphylococcus epidermidis (4.71%) respectively. Candida albicans were the main fungus which accounted for 5.43%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were 3.5%-6.1% and 5.0%-6.3% respectively. The rates of Pseudomonas aeruginosa resistant to tobramycin and amikacin were 3.2% and 3.3% respectively. The resistant rates of Acinetobacter baumannii towards tobramycin and cefoperazone/sulbactam were both 19.2%. The rates of Stenotrophomonas maltophilia resistant to minocycline and sulfamethoxazole were 3.5% and 9.3% respectively. The rates of Staphylococcus aureus, Enterococcus faecium and Enterococcus faecalis resistant wards vancomycin were 0, 6.4% and 1.4% respectively; also, the rates of them resistant to linezolid were 1.2%, 0 and 1.6% respectively; in addition, the rates of them resistant to teicoplanin were 2.8%, 14.3% and 8.0% respectively. Furthermore, MRSA accounted for 39.15% (83/212) . Conclusions: Pathogens were mainly gram-negative bacteria. CRE accounted for 6.68%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were lower compared with other antibacterial agents. The rates of gram-positive bacteria resistant to vancomycin, linezolid and teicoplanin were still low. MRSA accounted for 39.15%.

[Analysis of high-risk HPV infection and cervical cytologic screening in HIV positive women]

Objective: To analysis of high-risk HPV infection and cervical cytologic screening in HIV positive women, and to study the relationship between HIV infection and high-risk HPV infection. Methods: From June 2011 to May 2016, 58 cases of HIV positive women in Beijing Ditan Hospital for cervical screening were selected as the experimental group, and 59 cases of HIV negative women were selected as control group, thin-prep cytologic test(TCT)and HPV detection were used in two groups of subjects. The abnormal rate of TCT and the incidence rate of HPV were observed in the two groups, the relationship between HIV infection and HPV infection was analyzed. Results: TCT abnormal rate(91.4%, 53/58)of the experimental group was obviously higher than that of the control group(45.8%, 27/59), with statistically significant(χ²=12.365, P=0.036). High-risk HPV infection incidence(34.5%, 20/58)of the experimental group was significantly higher than that of the control group(16.9%, 10/59), with traditional significance(χ²=10.359, P=0.041). CD₄⁺ T lymphocytes and CD₄⁺/CD₈⁺ ratio of high-risk HPV positive patients had significant difference with high-risk HPV negative patients(χ²=10.378, P=0.042; χ²=9.245, P=0.045). The proportion of different AIDS clinical stages of high-risk HPV positive patients had obvious difference with high-risk HPV negative patients(P<0.05). Conclusion: HIV positive women maybe have a large proportion of abnormal TCT and the infection with high-risk HPV, and infection of high-risk HPV in HIV positive women has relationship with CD₄⁺ T lymphocytes, CD₄⁺/CD₈⁺ ratio and AIDS clinical stage.

FOXC1 overexpression is a marker of poor response to anthracycline-based adjuvant chemotherapy in sporadic triple-negative breast cancer

Purpose

Because of its aggressive characteristics and poor prognosis, triple-negative breast cancer (TNBC) has become a hot topic in cancer research. Chemotherapy is currently the only treatment for patients with TNBC. The transcription factor FOXC1 has been associated with TNBC prognosis, but little is known about its effect on chemosensitivity. The aim of this study was to investigate the effects of FOXC1 on chemosensitivity.

Methods

A case–control study was performed on 25 TNBC patients who experienced relapse and/or metastasis. Another 25 patients without relapse or metastasis were randomly selected as controls. Medical records were reviewed for relevant information, and immunohistochemistry was performed to measure FOXC1 levels. The Kaplan–Meier method and Cox analysis were used to analyze differences in disease-free survival (DFS) and overall survival (OS). The correlation of FOXC1 expression with chemosensitivity was analyzed. Data were analyzed using SPSS 21.0 software, and a P value <0.05 was considered to be statistically significant.

Results

In 15 of 22 case patients, FOXC1 was overexpressed, whereas only 8 control patients exhibited FOXC1 overexpression (P < 0.05). FOXC1 expression had no correlation with pathological indicators. An anthracycline-based regimen was administered to 21 study patients and 23 control patients. FOXC1 expression was significantly associated with a worse DFS (HR 2.62, 95% CI 1.05–6.50, P = 0.038) but presented no correlation with OS (HR 2.53, 95% CI 0.76–8.40, P = 0.131) among these 44 patients.

Conclusions

This study shows that FOXC1 is correlated with chemosensitivity to anthracycline and could be used as an indicator of chemosensitivity in sporadic TNBC.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-017-3319-4) contains supplementary material, which is available to authorized users.

The Pharmacological Heterogeneity of Nepenthone Analogs in Conferring Highly Selective and Potent κ-Opioid Agonistic Activities

To develop novel analgesics with no side effects or less side effects than traditional opioids is highly demanded to treat opioid receptor mediated pain and addiction issues. Recently, κ-opioid receptor (KOR) has been established as an attractive target, although its selective agonists could bear heterogeneous pharmacological activities. In this study, we designed and synthesized two new series of nepenthone derivatives by inserting a spacer (carbonyl) between 6α,14α-endo-ethenylthebaine and the 7α-phenyl substitution of the skeleton and by substituting the 17-N-methyl group with a cyclopropylmethyl group. We performed in vitro tests (binding and functional assays) and molecular docking operations on our newly designed compounds. The results of wet-experimental measures and modeled binding structures demonstrate that these new compounds are selective KOR agonists with nanomolar level affinities. Compound 4 from these new derivatives showed the highest affinity (K_i = 0.4 ± 0.1 nM) and the highest selectivity (μ/κ = 339, δ/κ = 2034) toward KOR. The in vivo tests revealed that compound 4 is able to induce stronger (ED₅₀ = 2.1 mg/kg) and much longer antinociceptive effect than that of the typical KOR agonist U50488H (ED₅₀ = 4.4 mg/kg). Therefore, compound 4 can be used as a perfect lead compound for future design of potent analgesics acting through KOR.

[Drug coated balloon with paclitaxel for the treatment of symptomatic peripheral artery disease: early and midterm results]

OBJECTIVE

To evaluate the safety and efficacy of the drug coated balloon (DCB) with paclitaxel in patients with symptomatic peripheral artery disease (PAD).

METHODS

The clinical data of 18 patients, who were diagnosed as PAD and treated with DCB from October 2013 to June 2014 in Department of Vascular Surgery, People's Liberation Army General Hospital, were retrospectively analyzed.Thirteen male and 5 female patients were in the series, the mean age of the patients was (65±7) years, and the Rutherford's categories were level 3 to 5. Patients were followed up at 3- and 6-month postoperative. The main efficacy end point were late lumen loss(LLL), rate of restenosis and clinically driven target lesion revascularization (TLR). Meanwhile, the clinical events were recorded.

RESULTS

Mean lesion length, the percentage of total occlusions and the percentage of in-stent restenosis were (138±91) mm, 9/18 and 2/18, respectively. Rate of technical success was 18/18. At 6-month postoperative, LLL, rate of restenosis and TLR were (0.1±0.9) mm, 2/14 and 0, respectively. There was no deaths or no amputations.

CONCLUSION

DCB with paclitaxel is safe in patients with PAD, and associated with reductions in LLL, restenosis and clinically driven TLR 6-month postoperative.

[Reconstruct abdominal aortic branch arteries totally by endovascular repair in complex aortic aneurysms: a single-centre experience]

OBJECTIVE

To report experiences and results of complex aortic aneurysms involving the visceral arteries treating by total endovascular repair.

METHODS

Seventy cases of thoracoabdominal aortic lesions treating by total endovascular repair in Department of Vascular Surgery, People's Liberation Army General Hospital from January 2011 to December 2014 were retrospectively analyzed. There were 47 cases underwent chimney technique, 6 underwent sandwich technique, 15 underwent fenestration technique and 2 underwent branched stent grafts technique.

RESULTS

The average follow-up time was 21 months, range from 3 to 47 months. Completion angiography showed that typeⅠ endoleak of chimney, sandwich, fenestration and branched stent grafts group were 9/47, 5/6, 2/15 and 0, respectively. While at 30-day typeⅠ endoleak reduced to 7/47, 2/6, 0 and 0. During follow-up, there were 3 target vessel stents occlusion in chimney group, the patency rate of target vessel stent was 95.1% (58/61). In sandwich, fenestration and branched stent grafts group, all the target vessel stents kept patent.

CONCLUSION

In this study, chimney, sandwich, fenestration and branched stent grafts techniques show good short-term and midterm results, the long-term effects still need further studies.

Adaptive synchronization and parameter identification of chaotic system with unknown parameters and mixed delays based on a special matrix structure

In this paper, we investigate the synchronization and parameter identification of chaotic system with unknown parameters and mixed delays. A new approach is proposed for designing a controller and a update rule of unknown parameters based on a special matrix structure, and the synchronization and the parameter identification are realized under the controller and the update rule. Numerical simulations are carried out to confirm the effectiveness of the approach. A significant advantage is that the process of designing a controller and a update rule become very clear and easy by the proposed approach.

Microbial diversity in the oral cavity of healthy Chinese Han children

OBJECTIVE

This study aimed to identify the oral microbial diversity of healthy Chinese Han children.

METHODS

Dental plaques were sampled from the oral cavity of ten healthy Chinese Han children. The oral microbiome was examined using the 16S rRNA-based Human Oral Microbe Identification Microarray. The microbial diversity and similarity were analyzed using the Chao-Jaccard similarity index.

RESULTS

A total of 112 species, which belonged to nine bacterial phyla and 41 genera, were detected. Each individual harbored an average of 54.1 microbial species (ranging from 37 to 69) and 26.2 genera (ranging from 21 to 31), with interindividual variations both at the species and genus level. Thirteen genera were conserved among all individuals. The Chao-Jaccard similarity index averages, at the genus and species level, were 0.642 (ranging from 0.485 to 0.871) and 0.506 (ranging from 0.338 to 0.676), respectively, suggesting that the healthy oral community was more conserved at the genus level than at the species level.

CONCLUSION

Although there was interindividual variation in the oral microflora, some bacterial genera were conserved among individuals, supporting the existence of a core microbiome in the oral cavity of healthy Chinese Han children.

Investigation of characteristics of feather follicle stem cells and their regeneration potential

Feather follicles have the extraordinary ability to regenerate and undergo molting cycles. Being tissue-specific stem cells, feather follicle stem cells (FFSCs) have a strong capacity for proliferation and are presumed to be progenitor cells for various epidermal organs. In order to characterize FFSCs and to understand how the feather epidermis and FFSCs produce such a reliable differentiation program resulting in the formation of complex feathers, We developed a culture scheme to select and expand FFSCs from chick feather follicles. FFSCs were examined with cell profiles, mutilpotential differentiation and immunocytochemical staining. FFSCs from a single clone were capable of self-renewal and proliferation. These cells expressed integrin β1, CD49c, cytokeratin 15 (K15), cytokeratin 19 (K19) and a neural-genic cell marker, nestin, but not a teminal differentiation-related keratinocyte marker, cytokeratin 10 (K10). FFSCs could trans-differentiate into adipocytes, neurocytes and keratinocytes. The formation of micro-feather like structures ex-vivo also revealed the potential of regeneration. These results demonstrate that FFSCs possess the properties of stem/progenitor cells and may therefore serve as a useful model for studying mechanisms of stem cell differentiation and their involvement in organ regeneration.

Low propagation loss SiN optical waveguide prepared by optimal low-hydrogen module

We investigated low-hydrogen SiN films prepared by a low temperature (350 degrees C) PECVD method. The impact of SiH(4)/N(2) flow ratio and radio frequency power on the hydrogen content in the SiN films was studied. In this work, we demonstrated a low-loss sub-micron SiN waveguide by using the corresponding optimal SiN films. The propagation loss was found to be as low as -2.1+/-0.2 dB/cm at 1550 nm with waveguide cross-section of 700 nm x 400 nm. The results suggest that the SiN films grown by PECVD with low hydrogen can be used in photonics integrated circuits for new generation communications applications.

Proteomic analysis of human bone marrow mesenchymal stem cells transduced with human telomerase reverse transcriptase gene during proliferation

OBJECTIVES

Previous studies have reported immortalization and tumorigenicity of human mesenchymal stem cells (hMSCs) transduced with exogenous human telomerase reverse transcriptase (hTERT). We also have established a line of hMSCs transduced with hTERT (hTERT-hMSCs) and we have cultured these cells for 290 population doublings (PDs) during which they demonstrated a large proliferation potential but with no tumorigenicity. The aim of this study was to investigate the protein expression profile of hTERT-hMSCs with two-dimensional gel electrophoresis and peptide mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, to be able to analyse the effects of exogenous hTERT on protein expression in hMSCs.

MATERIALS AND METHODS

We generated proteome maps of primary hMSCs and hTERT-hMSCs at PD 95 and PD 275.

RESULTS

A total of 1543 +/- 145 protein spots in gels of primary MSCs at PD 12, 1611 +/- 186 protein spots in gels of hTERT-hMSCs at PD 95 and 1451 +/- 126 protein spots in gels of hTERT-hMSCs at 275 PD were detected. One hundred of these were successfully identified, including 20 which were differentially expressed.

CONCLUSIONS

The results suggest that sustaining levels of prohibitin and p53 expression along with differential expression of proteins in hTERT-hMSCs provide an insight into lack of transforming activity of hTERT-hMSCs during cell proliferation.

Two new diterpenoids from Coleus forskohlii

Two new diterpenoids, forskolins I and J, have been isolated in our further investigation on Coleus forskohlii (Willd.) Briq. collected in Yunnan Province. Their structures have been determined as 1alpha,6beta-diacetoxy-7beta,9alpha-dihydroxy-8,13-epoxylabd-14-en-11-one (1) and 1alpha,9alpha-dihydroxy-6beta,7beta-diacetoxy-8,13-epoxylabd-14-en-11-one (2) by spectral methods (including 1D and 2D NMR techniques).

ent-Isopimarane diterpenoids of the leaves from Rabdosia forrestii

Two new diterpenes, forrestin H, ent-isopimaran-8 beta, 15R, 16-triol (1), forrestin I, ent-isopimaran-16-acetoxy-8 beta, 15R-diol (2) and the acetonide derivative of forrestin H were isolated from the leaves of Rabdosia forrestii. The structures were established on the basis of NMR spectroscopic analysis and of the modified Mosher's (1H) method.

[Screening the mimic antigen epitopes of triosephosphate isomerase of Schistosoma japonicum Chinese strain (Sjc-Tpi) with random phage peptide library]

OBJECTIVE

To screen the mimic antigen epitopes of the triose phosphate isomerase of Schistosoma japonicum Chinese strain (SjC-TPI) and investigate their immunogenicity.

METHODS

The random phage peptide library (PH.D.-12) was screened with the purified antibody(IgG) against SjC-TPI to get the positive phage which contained the mimic antigen epitopes of SjC-TPI, and the immuno-characterization of the mimic antigen epitopes were investigated.

RESULTS

Two mimic antigen epitopes (M1, M2) of SjC-TPI were obtained. The immuno-sera of mice (Kunming strain) against the positive phages could recognize both the SjC-TPI and the protein of the positive phages. The DNA sequencing data showed no homology between the sequences of the deduced amino acid of the two mimic antigen peptides and the amino acid of SjC-TPI.

CONCLUSION

The two mimic antigen epitopes of SjC-TPI obtained are imitative epitopes of the configuration antigen of SjC-TPI.

[Protective immunity induced by 23 kDa membrane protein DNA vaccine of Schistosoma japonicum Chinese strain in mice]

OBJECTIVE

To develop 23 kDa membrane protein DNA vaccine of Schistosoma japonicum Chinese strain and test its protective efficacy in infected C57BL/6 mice.

METHODS

The full length cDNA encoding SjC23 amplified from pUC19-SjC23 subcloned into pcDNA3.1. 48 female mice were divided into three groups: A, B and C. Group A (control group) was each immunized i.m. with 100 micrograms of pcDNA3.1; group B (SjC23 group) was each immunized i.m. with 100 micrograms of pcDNA3.1-SjC23; group C (SjC23 + IL-12) was each immunized i.m. with a mixture of 100 micrograms of pcDNA3.1-SjC23, 100 micrograms of pcDNA3.1-p35 and 100 micrograms of pcDNA-p40, followed by two boosts of the same DNA once every two weeks. All the mice were challenged with 45 cercariae at week 8, killed and perfused for worms at week 14. The expression of SjC23 and p35, p40 in muscle tissue was determined by immuno-histochemical method. By the culture of spleen cells, the production of IL-2, IL-4, IL-10 and IFN-gamma after the stimulation of rSjC23-HD was determined two weeks before and after challenge. Anti-SjC23 antibodies were tested by Western blotting.

RESULTS

SjC23 and p35, p40 were all expressed on the membrane and in the plasma of muscle cells of the infected mice. Significant increase of IL-2 and IFN-gamma in SjC23 and SjC23 + IL-12 groups was observed before and after challenge. Western blotting showed that after the third immunization (before challenge) 8 out of 10 sera from SjC23 group and 9 out of 10 sera from SjC23 + IL-12 group were positive. The worm reduction rate in SjC23 group and SjC23 + IL-12 group was 26.9% and 35.4%, respectively; the number of eggs in liver tissue was reduced by 22.2% and 28.4%, respectively.

CONCLUSION

pcDNA3.1-SjC23 DNA vaccine could induce partial protection against Schistosoma japonicum in C57BL/6 mice.

Seroprevalence of known and putative hepatitis markers in United States blood donors with ALT levels at least 120 IU per L

BACKGROUND

ALT testing of blood donors was initiated as a surrogate marker for non-A, non-B hepatitis. Increased sensitivity of subsequent HBV and HCV tests used for standard donor screening make any residual value of ALT testing questionable.

STUDY DESIGN AND METHODS

A prospective study was conducted in 166 of 645 eligible blood donors from three American Red Cross regions whose ALT was > or =120 IU per L and whose standard donor screening tests were negative. Of these enrolled donors, 124 (75%) completed follow-up. Samples obtained from the index donation, at enrollment (1 month), and at follow-up (6 months) underwent the standard donor screening tests, as well as those for HCV RNA and HGV RNA (RT-PCR), antibodies to the virus envelope E2 protein of GB virus type C (GBV-C E2 antibody), and IgM antibody for CMV, parvovirus B19, EBV VCA, and HAV. Participants completed a brief demographic and exposure history questionnaire at follow-up.

RESULTS

All study samples were negative in standard donor-screening tests. ALT levels were variable at return visits, with 80 to 86 percent <120 IU per L. No participants were positive for HCV RNA; 4 percent were positive for HGV RNA, and 10 percent were positive for GBV-C E2 antibody. Results of CMV, parvovirus B19, EBV VCA, and HAV testing were similar to published background rates. No demographic or exposure history variables had significant correlation with ALT or other testing results.

CONCLUSION

These data suggest that an ALT > or =120 IU per L in blood donors with negative standard screening tests has questionable value as a surrogate marker for seronegative HBV or HCV infection. Continued ALT testing may contribute little, if anything, to the safety of blood components or plasma for further manufacture.

[The application of submental island flap in head and neck surgery]

OBJECTIVE

This article discusses the anatomy, surgical procedure,indication, advantages and disadvantages of the submental island flap in reconstruction of the defects after head and neck tumor surgery, based on our clinical experience.

METHODS

The submental island flap was transferred with the submental vessels(A/V) as pedicle. In harvesting the flap, the flap was raised commencing from the contralateral side, dissecting all tissues off the mylohyoid muscles. Submandibular triangle dissection was taken until the facial artery and the facial vein. Then the submandibular gland and submandibular nodes were removed and submental vessels were left. This produces a large skin paddle which can be tunnelled to its recipient site.

RESULTS

From Aug. 1998 to Oct. 1999, 16 submental island flaps were performed in our department. 15 flaps survived well and 1 flap failed, with a success rate of 15/16 (93.8%).

CONCLUSION

The submental island flap is appropriate for primary reconstruction of the defect after various head and neck tumor surgery. It has a long and reliable pedicle, rapid and simple to raise and free from vessel anastomosis. It leaves a well hidden donor site. However, it can't be applied to these cases whose donor site had been radiated before surgery and whose submental and submandibular triangles lymph nodes were positive.

Calculation of the heat-source function in photophoresis of aggregated spheres

We present theoretical results for the source function in photophoresis of an arbitrary aggregate of spheres that are homogeneous and isotropic piecewise. This source function directly represents the distribution of electric fields inside the spheres. Our calculation is based on a rigorous analytic solution to the radiative multisphere-scattering problem developed recently [Y.-l. Xu, Appl. Opt. 34, 4573 (1995); 36, 9496 (1997); Phys. Lett. A 249, 30 (1998)]. When an aggregate degenerates to a single sphere, the results are exactly the same as those given by the Mie theory. We also discuss the numerical techniques necessary for obtaining an accurate numerical solution for the source function.

Feedback regulation of GA5 expression and metabolic engineering of gibberellin levels in Arabidopsis

The gibberellin (GA) 20-oxidase encoded by the GA5 gene of Arabidopsis directs GA biosynthesis to active GAs, whereas that encoded by the P16 gene of pumpkin endosperm leads to biosynthesis of inactive GAs. Negative feedback regulation of GA5 expression was demonstrated in stems of Arabidopsis by bioactive GAs but not by inactive GA. In transgenic Arabidopsis plants overexpressing P16, there was a severe reduction in the amounts of C20-GA intermediates, accumulation of large amounts of inactive GA25 and GA17, a reduction in GA4 content, and a small increase in GA1. However, due to feedback regulation, expression of GA5 and GA4, the gene coding for the subsequent 3beta-hydroxylase, was greatly increased to compensate for the effects of the P16 transgene. Consequently, stem height was only slightly reduced in the transgenic plants.