Adrenalectomy for pheochromocytoma: Surgical outcomes and preoperative risk factors for hemodynamic instability.

BACKGROUND: Surgical resection for pheochromocytoma (PCC) is still challenging. This study assessed the perioperative outcomes of adrenalectomy for PCC and investigated the risk factors for intraoperative hemodynamic instability (HI). METHODS: This retrospective study included 571 patients with adrenal tumors who underwent adrenalectomy at Kobe University Hospital and other related hospitals between April 2008 and October 2023. The perioperative outcomes of laparoscopic adrenalectomy were compared between PCC (n = 92) and non-PCC (n = 464) groups. In addition, we investigated several potential risk factors for intraoperative HI in patients with PCC (n = 107; open, n = 11; laparoscopic, n = 92; robot-assisted, n = 4). RESULTS: While patients with PCC had a significantly larger amount of blood loss in comparison to those with non-PCC (mean, 70 and 30 mL, respectively; p = 0.004), no significant difference was observed in the rate of perioperative grade ≥III complications (1.1% vs. 0.6%; p = 0.516), and no perioperative mortality was observed in either group. A tumor size of ≥40 mm, with preoperative hypertension and urinary metanephrines at a level ≥3 times the upper limit of the normal value, were found to be significant predictors of HI, with odds ratios of 2.74 (p = 0.025), 3.91 (p = 0.005), and 3.83 (p = 0.004), respectively. CONCLUSIONS: Our data suggest that laparoscopic adrenalectomy for PCC may be as safe as that for other types of adrenal tumors and that large tumors and hormonally active disease may be risk factors for intraoperative HI. The optimal perioperative management for PCC with these risk factors should be established.

Protective effects of tadalafil against cisplatin-induced spermatogenic dysfunction.

BACKGROUND: Cisplatin (CDDP) is an effective anticancer drug for the treatment of malignant tumors, such as lung cancer, bladder cancer, and testicular cancer. However, oligozoospermia and azoospermia after administration of CDDP are clinical problems. One of the testicular toxicities of CDDP is known to cause oxidative stress. Tadalafil has been reported to exhibit antioxidant effects and is widely used in clinical practice to treat benign prostatic hyperplasia and erectile dysfunction. Rho-kinase α (ROCK2) regulates cell migration and apoptosis and has been reported to be involved in CDDP-induced nephrotoxicity. The excessive expression of ROCK2 is known to cause oxidative stress. OBJECTIVE: The objective of the current study was to test the effect of tadalafil on the testicular toxicity of CDDP. MATERIAL AND METHODS: Thirty-two rats were used and divided into the following four groups. (1) The control group (CONT), treated with saline on day 1 and saline and dimethyl sulfoxide (DMSO) on days 1-10 intraperitoneally (i.p.) (2) The Tadalafil Group (TAD), treated with saline on day 1, and 0.4 mg/kg tadalafil on days 1-10 i.p. (3) The CDDP group (CD), treated with 7 mg/kg CDDP, saline, and DMSO on days 1-10 i.p. and (4) The CDDP + TAD group (CDT) was treated with 7 mg/kg CDDP on day 1, and 0.4 mg/kg tadalafil on days 1-10 i.p. Testes and epididymides samples were collected on day 11. Biochemical and pathological analyses and quantitative polymerase chain reaction were performed on the excised specimens. RESULTS: CDDP treatment resulted in testicular atrophy, decreased sperm concentration, and atrophy of seminiferous tubules as observed from the testicular histology. Increased apoptosis of seminiferous tubules, oxidative stress, and ROCK2 mRNA expression were observed after CDDP treatment. Treatment with tadalafil improved these adverse effects. CONCLUSION: Tadalafil is a potential drug for reducing CDDP-induced spermatogenic dysfunction. The antioxidant effect of tadalafil may be partly responsible for this phenomenon. ROCK2 and oxidative stress markers may be involved in the possible antioxidant effects of tadalafil. Tadalafil may be considered as one of a treatment option for reducing spermatogenic dysfunction after administration of CDDP.

Structure of tRNA methyltransferase complex of Trm7 and Trm734 reveals a novel binding interface for tRNA recognition.

The complex between Trm7 and Trm734 (Trm7-Trm734) from Saccharomyces cerevisiae catalyzes 2'-O-methylation at position 34 in tRNA. We report biochemical and structural studies of the Trm7-Trm734 complex. Purified recombinant Trm7-Trm734 preferentially methylates tRNAPhe transcript variants possessing two of three factors (Cm32, m1G37 and pyrimidine34). Therefore, tRNAPhe, tRNATrp and tRNALeu are specifically methylated by Trm7-Trm734. We have solved the crystal structures of the apo and S-adenosyl-L-methionine bound forms of Trm7-Trm734. Small angle X-ray scattering reveals that Trm7-Trm734 exists as a hetero-dimer in solution. Trm7 possesses a Rossmann-fold catalytic domain, while Trm734 consists of three WD40 ß-propeller domains (termed BPA, BPB and BPC). BPA and BPC form a unique V-shaped cleft, which docks to Trm7. The C-terminal region of Trm7 is required for binding to Trm734. The D-arm of substrate tRNA is required for methylation by Trm7-Trm734. If the D-arm in tRNAPhe is docked onto the positively charged area of BPB in Trm734, the anticodon-loop is located near the catalytic pocket of Trm7. This model suggests that Trm734 is required for correct positioning of tRNA for methylation. Additionally, a point-mutation in Trm7, which is observed in FTSJ1 (human Trm7 ortholog) of nosyndromic X-linked intellectual disability patients, decreases the methylation activity.

[A PEDIATRIC CASE OF DIFFUSE PANBRONCHIOLITIS WHO PREDOMINANTLY SHOWED RESTRICTIVE PULMONARY DYSFUNCTION AND DRAMATICALLY RESPONDED TO MACROLIDE LOW-DOSE LONG-TERM THERAPY.]

A 12-year-old boy visited our hospital with complaints of chronic cough and dyspnea. Chest X-ray and CT revealed diffuse granular shadow in the bilateral lung fields and "Tree-in-bud appearance" in the peripheral airways, respectively. Sinusitis was present, and restrictive disorder was predominantly found in pulmonary function. The patient was diagnosed with DPB, and long-term therapy was started with low-dose clarithromycin (CAM), The patient showed a dramatic response to CAM, with improvements of both the clinical symptoms and pulmonary function within 1-2 months. According to the relevant literature, in adult patients with this disease, pulmonary dysfunction starts from an obstructive pattern; however, this is not the case in pediatric patients. It was therefore suggested that the mechanisms underlying the development of pulmonary dysfunction in cases of childhood onset differs from those with an adult onset.

[A CASE OF VOCAL CORD DYSFUNCTION, WHO USED ADRENALIN AUTOINJECTOR (EPIPEN®) FREQUENTLY AFTER BEING DIAGNOSED AS ANAPHYLAXIS].

We experienced a case of vocal cord dysfunction (VCD) in a child to whom an adrenaline autoinjector (Epipen®) had been prescribed and frequently used following a diagnosis of exercise-induced anaphylaxis. An exercise test was performed to investigate her frequent episodes of anaphylaxis-like symptoms. A few minutes after starting the test, signs of dyspnea, such as throat tightness and stridor, appeared, although hypoxia was not present and her respiratory sounds were normal. Medications were not effective for treating her respiratory symptoms. Laryngoscopy performed at the test revealed bizarre vocal cord movement, which was diagnosed as VCD. The symptoms gradually diminished after the initiation of biofeedback therapy, including pursed lips breathing and abdominal breathing. Thereafter, she did not use an adrenaline autoinjector when symptoms appeared; instead, she would perform biofeedback therapy before using the adrenaline autoinjector. Thus, VCD should be included in the differential diagnosis of patients who show anaphylactic symptoms that are resistant to preventive therapy.

Sperm retrieval from a male with the rare 47, XXYqs variant of Klinefelter syndrome for intracytoplasmic sperm injection: A case report.

A 27-year-old man with nonobstructive azoospermia was diagnosed with Klinefelter syndrome (KS) with a satellite Y chromosome (47, XXYqs) by karyotyping. Genetic analysis revealed azoospermia factor c (AZFc) microdeletion of gr/gr deletion in the Y chromosome. Microdissection testicular sperm extraction (micro-TESE) was performed in bilateral testes. Very few seminiferous tubules were bilaterally observed, and a minute number of spermatozoa obtained from the left testis were cryopreserved. Histologic examination of the left testicular tissue revealed severe tubular atrophy with only Sertoli cells accompanied by Leydig cell hyperplasia. Oocyte harvest was conducted in his wife in two different cycles after ovarian stimulation, and intracytoplasmic sperm injection was performed for 24 oocytes (8 and 16 oocytes respectively) using thawed spermatozoa. Fertilisation was confirmed in total of 19 oocytes (79.2%), with 15 cleaved embryos (62.5%). Two cleavage-stage embryos were cryopreserved at day 2, but no blastocysts developed. Frozen-thawed embryo transfer was performed using two cleavage-stage (day 2) embryos; however, the wife did not conceive. In conclusion, spermatozoa were successfully obtained by micro-TESE from a patient with 47, XXYqs. Despite failure of conception, the fertilisation and cleavage rates were comparable or better than those reported in patients with "typical" KS.

Effect of mirabegron on tight junction molecules in primary cultured rat Sertoli cells.

Mirabegron is a selective beta3-adrenoceptor (ß3 -AR) agonist, which is commonly used for the treatment of overactive bladder. This medicine is associated with atrophy of reproductive organs in rats. However, no study has examined the detailed action and mechanism of its toxicity in reproductive cells. In this study, we examined the effect of mirabegron on primary cultured rat Sertoli cells. Firstly, RT-PCR and immunocytochemistry revealed that ß3 -AR was present in rat Sertoli cells. Then, primary cultured rat Sertoli cells were treated with mirabegron. Quantitative real-time PCR revealed that mirabegron treatment induced a significant increase in claudin-11 mRNA, which is crucial for spermatogenesis. Western blot analysis also showed that mirabegron treatment significantly activated p44/42 mitogen-activated protein kinase (MAPK). After additional treatment with U0126, a specific noncompetitive inhibitor of mitogen-activated protein kinase kinase (MAPKK), the upregulation of claudin-11 mRNA induced by mirabegron was reduced. At the same time, immunocytochemistry showed mirabegron treatment disturbed claudin-11 localisation to tight junction, which was recovered when treated with mirabegron in the presence of U0126. These results suggest that mirabegron treatment is associated with assembly of the blood-testis barrier through p44/42 MAPK pathway. These findings could explain one of the underlying mechanisms of reproductive toxicity induced by mirabegron.

Evaluating the Raftophilicity of Rhodopsin Photoreceptor in a Patterned Model Membrane.

Lipid rafts in the cell membrane are believed to affect various membrane functions, including the signaling by G-protein coupled receptors (GPCRs). However, the regulatory roles of lipid rafts on GPCRs' functions are still poorly understood, partially owing to the lack of the methods to quantitatively evaluate the affinity of membrane proteins to lipid raft (raftophilicity). Here, we describe a methodology to gauge the raftophilicity of a representative GPCR in vertebrate photoreceptor, i.e., rhodopsin (Rh), and its cognate G protein transducin (Gt) by using a patterned model membrane. We generated a substrate-supported planar lipid bilayer that has patterned regions of liquid-ordered (Lo) and liquid-disordered (Ld) membrane domains. We reconstituted Rh and Gt into the patterned membrane and observed their lateral distribution and diffusion. Mobile and functional Rh molecules could be reconstituted through the rapid dilution of solubilized Rh, by optimizing the reconstitution conditions including the chamber design, protein/detergent concentrations, and solution mixing. We determined the partition and diffusion coefficients of Rh and Gt in the Lo-rich and Ld-rich regions. Both Rh and Gt were predominantly localized in the Ld phase, suggesting their low affinity to lipid rafts. Patterned model membrane offers a robust and scalable platform for systematically and quantitatively studying the functional roles of lipid rafts in biological membranes including retinal disk membranes.

Critical function of RA-GEF-2/Rapgef6, a guanine nucleotide exchange factor for Rap1, in mouse spermatogenesis.

Small GTPase Rap1 has been implicated in the proper differentiation of testicular germ cells. In the present study, we investigated the functional significance of RA-GEF-2/Rapgef6, a guanine nucleotide exchange factor for Rap1, in testicular differentiation using mice lacking RA-GEF-2. RA-GEF-2 was expressed predominantly on the luminal side of the seminiferous tubules in wild-type mice. No significant differences were observed in the body weights or hormonal parameters of RA-GEF-2(-)(/)(-) and wild-type mice. However, the testes of RA-GEF-2(-)(/)(-) male mice were significantly smaller than those of wild-type mice and were markedly atrophied as well as hypospermatogenic. The concentration and motility of epididymal sperm were also markedly reduced and frequently had an abnormal shape. The pregnancy rate and number of fetuses were markedly lower in wild-type females after they mated with RA-GEF-2(-)(/)(-) males than with wild-type males, which demonstrated the male infertility phenotype of RA-GEF-2(-)(/)(-) mice. Furthermore, a significant reduction and alteration were observed in the expression level and cell junctional localization of N-cadherin, respectively, in RA-GEF-2(-)(/)(-) testes, which may, at least in part, account for the defects in testicular differentiation and spermatogenesis in these mice.

Comprehensive evaluation of androgen replacement therapy in aging Japanese men with late-onset hypogonadism.

OBJECTIVE: This study assessed the efficacy and safety of testosterone replacement therapy (TRT) in aging Japanese men with late-onset hypogonadism (LOH). METHODS: This study included 50 (median age: 57.7 years) Japanese men with LOH, who were consecutively enrolled and treated with TRT for at least six months at our institution. We evaluated the following measurements before and after six months of treatment with TRT as follows: blood tests, prostate volume, residual urine volume, self-ratings for International Index of Erectile Function 5 (IIEF-5), International Prostate Symptom Score (IPSS), Self-Rating Depression Scale (SDS), Aging Male Symptom (AMS) and the Medical Outcomes Study 8-item Short-Form health survey (SF-8). RESULTS: Following six months of TRT, the levels of testosterone, red blood cells, hemoglobin and hematocrit were significantly increased from baseline, while total cholesterol level was significantly decreased from baseline. Furthermore, TRT led to a significant increase in IIEF-5 score and a significant decrease in IPSS score. Of 30 men who were diagnosed with depression at baseline, only 11 men (36.7%) were still suffering from depression after TRT, and SDS scores were significantly decreased from baseline at month six. Treatment with TRT led to a significant decrease in all scores of the AMS scale as well as a significant improvement in all scores of the SF-8 survey, with the exception of the bodily pain score. CONCLUSION: These findings suggest that TRT is an effective and safe treatment for aging Japanese men with LOH. TRT improved depressive symptoms as well as health-related quality of life.

Premature Chromatid Separation Trait Found During the Diagnosis of Male Infertility: A Case Report.

Premature chromatid separation (PCS)/mosaic variegated aneuploidy (MVA) syndrome is a rare chromosome instability syndrome. This syndrome is inherited in an autosomal recessive pattern. Although heterozygous carriers of a monoallelic mutation reportedly have a normal phenotype, PCS-positive cells are found at a higher rate in such carriers than in the general population. We herein report a case in which a PCS carrier was incidentally diagnosed during investigation of male infertility. A diagnosis of nonobstructive azoospermia was made, and chromosome analysis revealed the PCS trait in 81 of 200 cells (40.5%), indicating that the patient was a PCS carrier. PCS carriers are not uncommon, and if both members of a couple are carriers, there would be a 25% likelihood of the child presenting with PCS syndrome. Therefore, a clinical psychological approach that includes genetic counseling should be considered before proceeding to microsurgical testicular sperm extraction.

Fertility preservation in men with hypogonadotropic hypogonadism secondary to germinoma: two cases of gonadotropin replacement therapy before induction of anticancer chemotherapy.

Hypogonadotropic hypogonadism can be caused by brain tumors. For a malignancy such as a germ cell tumor, chemotherapy combined with radiation is administered. In patients who wish for children, the inability to undergo sperm cryopreservation before treatment because of impaired spermatogenesis and/or ejaculation dysfunction can be problematic. We herein present two cases involving a 26-year-old man and a 30-year-old man with hypogonadotropic hypogonadism due to an intracranial germinoma and both wished to have children. Gonadotropin replacement therapy prior to anticancer chemotherapy resulted in subsequent spontaneous pregnancy or assisted reproductive therapy. Subsequent treatment of the tumor resulted in no recurrence for 9 and 2 years, respectively. Close consultation with an oncologist is mandatory in such cases. Depending on the tumor prognosis, however, it may be possible to delay tumor treatment and prioritize fertility because there is a possibility of impaired spermatogenesis due to additional chemotherapy.

Clinical Outcomes and Risk Stratification in Patients With Metastatic Hormone-Sensitive Prostate Cancer Treated With New-Generation Androgen Receptor Signaling Inhibitors.

BACKGROUND: Optimal drug selection for metastatic hormone-sensitive prostate cancer (mHSPC) remains unclear. We therefore assessed the clinical outcomes of mHSPC treated with new-generation androgen receptor pathway inhibitors (ARSIs) and identified risk factors associated with the prognosis of mHSPC. METHODS: We retrospectively reviewed 324 patients with mHSPC who were treated with ARSIs, including abiraterone acetate, enzalutamide, and apalutamide, between January 2018 and December 2022. In addition to assessing the prostate-specific antigen (PSA) response and overall survival (OS) during ARSI treatment, we investigated several potential risk factors for a poor OS in patients with mHSPC. RESULTS: Patients with a ≥ 90% PSA reduction (hazard ratio [HR]: 0.24, 95% confidence interval [CI], 0.10-0.58; P = .002) and those whose PSA declined to ≤ 0.2 ng/mL (HR: 0.22, 95% CI, 0.08-0.63; P = .005) showed significantly better OS than other patients. Gleason grade group 5 (GG5), presence of liver metastasis, and an LDH ≥ 250 U/L were identified as prognostic factors significantly associated with a poor OS, with HRs of 2.31 (95% CI, 1.02-5.20; P = .044), 7.87 (95% CI, 2.61-23.8; P < .001) and 3.21 (95% CI, 1.43-7.23; P = .005). CONCLUSION: We identified GG5, the presence of liver metastasis, and elevated LDH at the diagnosis as significant factors predicting the OS of mHSPC, but the choice of ARSIs did not affect the prognosis. The potential prognostic impact of these markers requires further investigation.

Does Varicocele Repair Improve Conventional Semen Parameters? A Meta-Analytic Study of Before-After Data.

PURPOSE: The purpose of this meta-analysis is to study the impact of varicocele repair in the largest cohort of infertile males with clinical varicocele by including all available studies, with no language restrictions, comparing intra-person conventional semen parameters before and after the repair of varicoceles. MATERIALS AND METHODS: The meta-analysis was performed according to PRISMA-P and MOOSE guidelines. A systematic search was performed in Scopus, PubMed, Cochrane, and Embase databases. Eligible studies were selected according to the PICOS model (Population: infertile male patients with clinical varicocele; Intervention: varicocele repair; Comparison: intra-person before-after varicocele repair; Outcome: conventional semen parameters; Study type: randomized controlled trials [RCTs], observational and case-control studies). RESULTS: Out of 1,632 screened abstracts, 351 articles (23 RCTs, 292 observational, and 36 case-control studies) were included in the quantitative analysis. The before-and-after analysis showed significant improvements in all semen parameters after varicocele repair (except sperm vitality); semen volume: standardized mean difference (SMD) 0.203, 95% CI: 0.129-0.278; p<0.001; I²=83.62%, Egger's p=0.3329; sperm concentration: SMD 1.590, 95% CI: 1.474-1.706; p<0.001; I²=97.86%, Egger's p<0.0001; total sperm count: SMD 1.824, 95% CI: 1.526-2.121; p<0.001; I²=97.88%, Egger's p=0.0063; total motile sperm count: SMD 1.643, 95% CI: 1.318-1.968; p<0.001; I²=98.65%, Egger's p=0.0003; progressive sperm motility: SMD 1.845, 95% CI: 1.537%-2.153%; p<0.001; I²=98.97%, Egger's p<0.0001; total sperm motility: SMD 1.613, 95% CI 1.467%-1.759%; p<0.001; l2=97.98%, Egger's p<0.001; sperm morphology: SMD 1.066, 95% CI 0.992%-1.211%; p<0.001; I²=97.87%, Egger's p=0.1864. CONCLUSIONS: The current meta-analysis is the largest to date using paired analysis on varicocele patients. In the current meta-analysis, almost all conventional semen parameters improved significantly following varicocele repair in infertile patients with clinical varicocele.

Efficient transfection of DNA into primarily cultured rat sertoli cells by electroporation.

The expression of exogenous DNA in Sertoli cells is essential for studying its functional genomics, pathway analysis, and medical applications. Electroporation is a valuable tool for nucleic acid delivery, even in primarily cultured cells, which are considered difficult to transfect. In this study, we developed an optimized protocol for electroporation-based transfection of Sertoli cells and compared its efficiency with conventional lipofection. Sertoli cells were transfected with pCMV-GFP plasmid by square-wave electroporation under different conditions. After transfection of plasmid into Sertoli cells, enhanced green fluorescent protein (EGFP) expression could be easily detected by fluorescent microscopy, and cell survival was evaluated by dye exclusion assay using Trypan blue. In terms of both cell survival and the percentage expressing EGFP, 250 V was determined to produce the greatest number of transiently transfected cells. Keeping the voltage constant (250 V), relatively high cell survival (76.5% ± 3.4%) and transfection efficiency (30.6% ± 5.6%) were observed with a pulse length of 20 µm. The number of pulses significantly affected cell survival and EGFP expression (P < 0.001). Cell survival clearly decreased following one to three pulses, from 83.9% ± 6.1% to 3.2% ± 1.1%, with EGFP expression increasing from 41.8% ± 9.4% to 66.7% ± 5.2%. The yield of positive cells increased with increasing concentration of plasmid DNA (range, 10-50 µg/ml), from 14.0% ± 2.8% to 35.0% ± 6.3%, but cell viability steadily decreased following 20 µg/ml plasmid DNA, from 73.1% ± 4.9% to 57.0% ± 6.6%. Compared with two popular cationic lipid transfection methods, the transfection efficiency of electroporation (21.5% ± 5.7%) was significantly higher than those of Lipofectamine 2000 (2.9% ± 1.0%) and Effectene (1.9% ± 0.8%) in this experiment (P < 0.001). We describe the process of optimizing electroporation conditions, and the successful electroporation of plasmid DNA into primarily cultured Sertoli cells. Our results indicate that the method of electroporation is more suitable than other approaches for the transfection of Sertoli cells.

Improvement in semen parameters by switching steroids in a male congenital adrenal hyperplasia patient with severe oligozoospermia.

Congenital adrenal hyperplasia (CAH) causes hypogonadotropic hypogonadism due to the excessive production of adrenal androgens, which results in hypospermatogenesis in some male patients. We herein present a CAH case with hypogonadotropic hypogonadism and male infertility. A 26-year-old male receiving steroid therapy for 21 hydroxylase deficiency was diagnosed with low gonadotropin levels, an elevated ACTH level, and severe oligozoospermia. The switching from hydrocortisone to dexamethasone resulted in the normalization of gonadotropin levels and semen findings. The couple underwent ICSI-ET, resulting in a live birth. In cases of CAH with hypospermatogenesis, the continuous suppression of ACTH by dexamethasone may restore spermatogenesis.

Effects of Bifidobacterium longum CLA8013 on bowel movement improvement: a placebo-controlled, randomized, double-blind study.

A placebo-controlled, randomized, double-blind study was conducted to evaluate the effect of taking 25 billion colony-forming units of heat-killed Bifidobacterium longum CLA8013 over 2 weeks on bowel movements in constipation-prone healthy individuals. The primary endpoint was the change in defecation frequency between the baseline and 2 weeks after the intake of B. longum CLA8013. The secondary endpoints were the number of days of defecation, stool volume, stool consistency, straining during defecation, pain during defecation, feeling of incomplete evacuation after defecation, abdominal bloating, fecal water content, and the Japanese version of the Patient Assessment of Constipation Quality of Life. A total of 120 individuals were assigned to two groups, 104 (control group, n=51; treatment group, n=53) of whom were included in the analysis. After 2 weeks of consuming the heat-killed B. longum CLA8013, defecation frequency increased significantly in the treatment group compared with that in the control group. Furthermore, compared with the control group, the treatment group showed a significant increase in stool volume and significant improvement in stool consistency, straining during defecation, and pain during defecation. No adverse events attributable to the heat-killed B. longum CLA8013 were observed during the study period. This study revealed that heat-killed B. longum CLA8013 improved the bowel movements of constipation-prone healthy individuals and confirmed that there were no relevant safety issues.

Formation of substrate-supported membranes from mixtures of long- and short-chain phospholipids.

We studied the formation of substrate-supported planar phospholipid bilayers (SPBs) on glass and silica from mixtures of long- and short-chain phospholipids to assess the effects of detergent additives on SPB formation. 1,2-Hexyanoyl-sn-glycero-3-phosphocholine (DHPC-C6) and 1,2-heptanoyl-sn-glycero-3-phosphocholine (DHPC-C7) were chosen as short-chain phospholipids. 1-Palmitoyl-2-oleol-sn-glycero-3-phosphocholine (POPC) was used as a model long-chain phospholipid. Kinetic studies by quartz crystal microbalance with dissipation monitoring (QCM-D) showed that the presence of short-chain phospholipids significantly accelerated the formation of SPBs. Rapid rinsing with a buffer solution did not change the adsorbed mass on the surface if POPC/DHPC-C6 mixtures were used below the critical micelle concentration (cmc) of DHPC-C6, indicating that an SPB composed of POPC molecules remained on the surface. Fluorescence microscopy observation showed homogeneous SPBs, and the fluorescence recovery after photobleaching (FRAP) measurements gave a diffusion coefficient comparable to that for SPBs formed from POPC vesicles. However, mixtures of POPC/DHPC-C7 resulted in a smaller mass of lipid adsorption on the substrate. FRAP measurements also yielded significantly smaller diffusion coefficients, suggesting the presence of defects. The different behaviors for DHPC-C6 and DHPC-C7 point to the dual roles of detergents to enhance the formation of SPBs and to destabilize them, depending on their structures and aggregation properties.