[Effects of comprehensive treatment of infected wounds in patients with iatrogenic Cushing's syndrome].

Objective: To investigate the characteristics and comprehensive treatment of infected wounds in patients with iatrogenic Cushing's syndrome. Methods: A retrospective observational study was conducted. From May 2012 to December 2021, the data of 19 patients with iatrogenic Cushing's syndrome discharged from the Department of Burns and Plastic Surgery of the First Affiliated Hospital of Guangxi Medical University were collected, including 8 males and 11 females, aged 28-71 (56±11) years, with 12 cases of infected acute wounds and 7 cases of infected chronic wounds. The lesions were located in the limbs, perianal, and sacrococcygeal regions, with original infection ranging from 9 cm×5 cm to 85 cm×45 cm. After admission, the patients were performed with multidisciplinary assisted diagnosis and treatment, and the wounds were treated with debridement and vacuum sealing drainage, according to the size, severity of infection, suture tension, and bone and tendon tissue exposure of wounds, direct suture or autologous skin and/or artificial dermis and/or autologous tissue flap transplantation was selected for wound repair. The levels of cortisol and adrenocorticotropic hormone (ACTH) of patients at 8:00, 16:00, and 24:00 within 24 h after admission were counted. After admission, the number of operations, wound repair methods, and wound and skin/flap donor site healing of patients were recorded. During follow-up, the wounds were observed for recurrent infection. Results: The cortisol levels of 16 patients at 8:00, 16:00, and 24:00 within 24 h after admission were (130±54), (80±16), and (109±39) nmol/L, respectively, and ACTH levels were (7.2±2.8), (4.1±1.8), and (6.0±3.0) pg/mL, respectively; and the other 3 patients had no such statistical results. After admission, the number of surgical operation for patients was 3.4±0.9. The following methods were used for wound repair, including direct suturing in 4 cases and autologous skin and/or artificial dermis grafting in 9 cases, of which 2 cases underwent stage Ⅱ autologous skin grafting after artificial dermis grafting in stage Ⅰ, and 6 cases had pedicled retrograde island flap+autologous skin grafting. The wound healing was observed, showing that all directly sutured wounds healed well; the wounds in 6 cases of autologous skin and/or artificial dermis grafting healed well, and the wounds in 3 cases also healed well after the secondary skin grafting; the flaps in 4 cases survived well with the wounds in 2 cases with distal perforators flap arteries circumfluence obstacle of posterior leg healed after stage Ⅱ debridement and autologous skin grafting. The healing status of skin/flap donor sites was followed showing that the donor sites of medium-thickness skin grafts in the thigh of 4 cases were well healed after transplanted with autologous split-thickness grafts from scalp; the donor sites of medium-thickness skin grafts in 3 cases did not undergo split-thickness skin grafting, of which 2 cases had poor healing but healed well after secondary skin grafting 2 weeks after surgery; the donor sites of split-thickness skin grafts in the head of 2 patients healed well; and all donor sites of flaps healed well after autologous skin grafting. During follow-up of more than half a year, 3 gout patients were hospitalized again for surgical treatment due to gout stone rupture, 4 patients were hospitalized again for surgical treatment due to infection, and no recurrent infection was found in the rest of patients. Conclusions: The infected wounds in patients with iatrogenic Cushing's syndrome have poor ability to regenerate and are prone to repeated infection. Local wound treatment together with multidisciplinary comprehensive treatment should be performed to control infection and close wounds in a timely manner, so as to maximize the benefits of patients.

Diffusion of water-soluble sorptive drugs in HEMA/MAA hydrogels.

We measure and, for the first time, theoretically predict four prototypical aqueous-drug diffusion coefficients in five soft-contact-lens material hydrogels where solute-specific adsorption is pronounced. Two-photon fluorescence confocal microscopy and UV/Vis-absorption spectrophotometry assess transient solute concentration profiles and concentration histories, respectively. Diffusion coefficients are obtained for acetazolamide, riboflavin, sodium fluorescein, and theophylline in 2-hydroxyethyl methacrylate/methacrylic acid (HEMA/MAA) copolymer hydrogels as functions of composition, equilibrium water content (30-90%), and aqueous pH (2 and 7.4). At pH2, MAA chains are nonionic, whereas at pH7.4, MAA chains are anionic (pKa≈5.2). All studied prototypical drugs specifically interact with HEMA and nonionic MAA (at pH2) moieties. Conversely, none of the prototypical drugs adsorb specifically to anionic MAA (at pH7.4) chains. As expected, diffusivities of adsorbing solutes are significantly diminished by specific interactions with hydrogel strands. Despite similar solute size, relative diffusion coefficients in the hydrogels span several orders of magnitude because of varying degrees of solute interactions with hydrogel-polymer chains. To provide a theoretical framework for the new diffusion data, we apply an effective-medium model extended for solute-specific interactions with hydrogel copolymer strands. Sorptive-diffusion kinetics is successfully described by local equilibrium and Henry's law. All necessary parameters are determined independently. Predicted diffusivities are in good agreement with experiment.

Equilibrium water and solute uptake in silicone hydrogels.

Equilibrium water content of and solute partitioning in silicone hydrogels (SiHys) are investigated using gravimetric analysis, fluorescence confocal laser-scanning microscopy (FCLSM), and back extraction with UV/Vis-absorption spectrophotometry. Synthesized silicone hydrogels consist of silicone monomer, hydrophilic monomer, cross-linking agent, and triblock-copolymer macromer used as an amphiphilic compatibilizer to prevent macrophase separation. In all cases, immiscibility of the silicone and hydrophilic polymers results in microphase-separated morphologies. To investigate solute uptake in each of the SiHy microphases, equilibrium partition coefficients are obtained for two hydrophilic solutes (i.e., theophylline and caffeine dissolved in aqueous phosphate-buffered saline) and two oleophilic solutes (i.e., Nile Red and Bodipy Green dissolved in silicone oil), respectively. Measured water contents and aqueous-solute partition coefficients increase linearly with increasing solvent-free hydrophilic-polymer volume fraction. Conversely, oleophilic-solute partition coefficients decrease linearly with rising solvent-free hydrophilic-polymer volume fraction (i.e., decreasing hydrophobic silicone-polymer fraction). We quantitatively predict equilibrium SiHy water and solute uptake assuming that water and aqueous solutes reside only in hydrophilic microdomains, whereas oleophilic solutes partition predominately into silicone microdomains. Predicted water contents and solute partition coefficients are in excellent agreement with experiment. Our new procedure permits a priori estimation of SiHy water contents and solute partition coefficients based solely on properties of silicone and hydrophilic homopolymer hydrogels, eliminating the need for further mixed-polymer-hydrogel experiments.

Fluorescent solute-partitioning characterization of layered soft contact lenses.

Partitioning of aqueous packaging, wetting, and care-solution agents into and out of soft contact lenses (SCLs) is important for improving wear comfort and also for characterizing lens physico-chemical properties. We illustrate both features of partitioning by application of fluorescent-solute partitioning into DAILIES TOTAL1® (delefilcon A) water-gradient SCLs, which exhibit a layered structure of a silicone-hydrogel (SiHy) core sandwiched between thin surface-gel layers. Two-photon fluorescence confocal laser-scanning microscopy and attenuated total-reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) characterize the lens and assess uptake profiles of six prototypical fluorescent solutes. Comparison of solute uptake in a SiHy-core prototype lens (i.e., O2OPTIX(TM)) validates the core SiHy structure of DAILIESTOTAL1®. To establish surface-layer charge, partition coefficients and water contents are obtained for aqueous pH values of 4 and 7.4. Solute fluorescence-intensity profiles clearly confirm a layered structure for the DAILIES TOTAL1® lenses. In all cases, aqueous solute partition coefficients are greater in the surface layers than in the SiHy core, signifying higher water in the surface gels. ATR-FTIR confirms surface-layer mass water contents of 82±3%. Water uptake and hydrophilic-solute uptake at pH 4 compared with that at pH 7.4 reveal that the surface-gel layers are anionic at physiologic pH 7.4, whereas both the SiHy core and O2OPTIX™ (lotrafilcon B) are nonionic. We successfully confirm the layered structure of DAILIES TOTAL1®, consisting of an 80-µm-thick SiHy core surrounded by 10-µm-thick polyelectrolyte surface-gel layers of significantly greater water content and aqueous solute uptake compared with the core. Accordingly, fluorescent-solute partitioning in SCLs provides information on gel structure and composition, in addition to quantifying uptake and release amounts and rates.

Ultrasensitive force detection with a nanotube mechanical resonator.

Since the advent of atomic force microscopy, mechanical resonators have been used to study a wide variety of phenomena, including the dynamics of individual electron spins, persistent currents in normal metal rings and the Casimir force. Key to these experiments is the ability to measure weak forces. Here, we report on force sensing experiments with a sensitivity of 12 zN Hz(-1/2) at a temperature of 1.2 K using a resonator made of a carbon nanotube. An ultrasensitive method based on cross-correlated electrical noise measurements, in combination with parametric downconversion, is used to detect the low-amplitude vibrations of the nanotube induced by weak forces. The force sensitivity is quantified by applying a known capacitive force. This detection method also allows us to measure the Brownian vibrations of the nanotube down to cryogenic temperatures. Force sensing with nanotube resonators offers new opportunities for detecting and manipulating individual nuclear spins as well as for magnetometry measurements.

An improved mechanical technique for assisted hatching.

BACKGROUND: Varied clinical outcomes of assisted hatching (AH) have been reported. We attempt to investigate whether the size of the zona opening created by AH is adequate for blastocyst hatching, and, if not, set up a new method to improve it. METHODS: A new AH technique, long zona dissection (LZD), was established, and experiments were performed to compare the effects of different sizes of zona opening on complete hatching of blastocysts in mouse and human embryos in vitro. RESULTS: The LZD technique can create a long zona slit on early embryos, even blastocysts, with the slit size beyond two-thirds of zona diameter. Compared with three-dimensional partial zona dissection, LZD can significantly enhance the hatching speed and the rate of complete hatching of mouse blastocysts (93.9%). All (100%) human blastocysts completely hatched following LZD; however, when the slit size after AH was about two-fifths of zona diameter, more of the larger inner cell masses (ICM) became trapped by the zona opening during hatching than the smaller ICM (53.3 versus 12.5%, P = 0.01). CONCLUSIONS: Zona opening of moderate size following AH is inadequate for the completion of blastocyst hatching in vitro; in some cases, however, it can be significantly improved by LZD.

[The design of axial pattern flap with color Doppler flow imaging technique].

OBJECTIVE: To study the effect of color doppler flow imaging(CDFI) technique in the design of axial pattern flap. METHODS: From April 1996 to June 1999, 10 patients with residual wound were adopted in this study. Among them, there were seven males and three females, the area of wounds ranged from 6 cm x 8 cm to 15 cm x 20 cm. Before operation, the axial pattern flaps were designed by traditional method, then CDFI technique with high frequency(5.0-7.5 MHz) was used for examining the major supply artery of the flap. At last, the modified flaps were transferred to cover the wounds. RESULTS: All the patients except one case completed the operation successfully. The cosmetic and function of the flaps were excellent. CONCLUSION: CDFI is a simple, direct and accurate method for detecting the supply artery of axial pattern flap. This technique should be popularized to avoid the blindness of flap design.