Strength of small-bites abdominal wall closure using different suturing methods and materials in an experimental animal model.

PURPOSE: Using small instead of large bites for laparotomy closure results in lower incidence of incisional hernia, but no consensus exists on which suture material to use. This study aimed to compare five different closure strategies in a standardized experimental setting. METHODS: Fifty porcine abdominal walls were arranged into 5 groups: (A) running 2/0 polydioxanone; (B) interlocking 2/0 polydioxanone; (C) running size 0 barbed polydioxanone; (D) running size 0 barbed glycolic acid and trimethylene carbonate; (E) running size 0 suturable polypropylene mesh. The small-bites technique was used for linea alba closure in all. The abdominal walls were divided into a supra- and infra-umbilical half, resulting in 20 specimens per group that were pulled apart in a tensile testing machine. Maximum tensile force and types of suture failure were registered. RESULTS: The highest tensile force was measured when using barbed polydioxanone (334.8 N ± 157.0), but differences did not reach statistical significance. Infra-umbilical abdominal walls endured a significantly higher maximum tensile force compared to supra-umbilical (397 N vs 271 N, p < 0.001). Barbed glycolic acid and trimethylene carbonate failed significantly more often (25% vs 0%, p = 0.008). CONCLUSION: Based on tensile force, both interlocking and running suture techniques using polydioxanone, and running sutures using barbed polydioxanone or suturable mesh, seem to be suitable for abdominal wall closure. Tensile strength was significantly higher in infra-umbilical abdominal walls compared to supra-umbilical. Barbed glycolic acid and trimethylene carbonate should probably be discouraged for fascial closure, because of increased risk of suture failure.

Athletes treated for inguinal-related groin pain by endoscopic totally extraperitoneal (TEP) repair: long-term benefits of a prospective cohort.

PURPOSE: Inguinal-related groin pain (IRGP) in athletes is a multifactorial condition, posing a therapeutic challenge. If conservative treatment fails, totally extraperitoneal (TEP) repair is effective in pain relief. Because there are only few long-term follow-up results available, this study was designed to evaluate effectiveness of TEP repair in IRGP-patients years after the initial procedure. METHODS: Patients enrolled in the original, prospective cohort study (TEP-ID-study) were subjected to two telephone questionnaires. The TEP-ID-study demonstrated favorable outcomes after TEP repair for IRGP-patients after a median follow-up of 19 months. The questionnaires in the current study assessed different aspects, including, but not limited to pain, recurrence, new groin-related symptoms and physical functioning measured by the Copenhagen Hip and Groin Outcome Score (HAGOS). The primary outcome was pain during exercise on the numeric rating scale (NRS) at very long-term follow-up. RESULTS: Out of 32 male participants in the TEP-ID-study, 28 patients (88%) were available with a median follow-up of 83 months (range: 69-95). Seventy-five percent of athletes were pain free during exercise (p < 0.001). At 83 months follow-up, a median NRS of 0 was observed during exercise (IQR 0-2), which was significantly lower compared to earlier scores (p <0.01). Ten patients (36%) mentioned subjective recurrence of complaints, however, physical functioning improved on all HAGOS subscales (p <0.05). CONCLUSION: This study demonstrates the safety and effectivity of TEP repair in a prospective cohort of IRGP-athletes, for whom conservative treatment had failed, with a follow-up period of over 80 months.

Relativistic effects on electronic pair densities: A perspective from the radial intracule and extracule probability densities.

While the effect of relativity in the electronic density has been widely studied, the effect on the pair probability, intracule, and extracule densities has not been studied before. Thus, in this work, we unveil new insights related to changes in the electronic structure caused by relativistic effects. Our numerical results suggest that the mean inter-electronic distance is reduced (mostly) due to scalar-relativistic effects. As a consequence, an increase in the electron-electron repulsion energy is observed. Preliminary results suggest that this observation is also valid when electronic correlation effects are considered.

Frequency Range Selection Method for Vibrational Spectra.

Theoretical calculations of vibrational properties are widely used to explain and predict experimental spectra. However, with standard quantum chemical methods all molecular motions are considered, which is rather time-consuming for large molecules. Because typically only a specific spectral region is of experimental interest, we propose here an efficient method that allows calculation of only a selected frequency interval. After a computationally cheap low-level estimate of the molecular motions, the computational time is proportional to the number of normal modes needed to describe this frequency range. Results for a medium-sized molecule show a reduction in computational time of up to 1 order of magnitude with negligible loss in accuracy. We also show that still larger computational savings are possible by using an additional intensity-selection procedure.

Use of Density Functional Based Tight Binding Methods in Vibrational Circular Dichroism.

Vibrational circular dichroism (VCD) is a spectroscopic technique used to resolve the absolute configuration of chiral systems. Obtaining a theoretical VCD spectrum requires computing atomic polar and axial tensors on top of the computationally demanding construction of the force constant matrix. In this study we evaluated a VCD model in which all necessary quantities are obtained with density functional based tight binding (DFTB) theory. The analyzed DFTB parametrizations fail at providing accurate vibrational frequencies and electric dipole gradients but yield reasonable normal modes at a fraction of the computational cost of density functional theory (DFT). Thus, by applying DFTB in composite methods along with DFT, we show that it is possible to obtain accurate VCD spectra at a much lower computational demand.

Effect of metallation, substituents and inter/intra-molecular polarization on electronic couplings for hole transport in stacked porphyrin dyads.

We carried out a systematic study of the hole transport properties for a series of symmetrically stacked porphyrin dimers. In the first part of this study, we evaluated the sensitivity of electronic couplings to orbital relaxation due to molecular ionization and intermolecular interactions for a series of halogenated porphyrins. The effect of polarization was estimated by comparing electronic couplings from fragment orbital density functional theory (FODFT) and frozen density embedding electron transfer (FDE-CT). For the dimers considered, the effect of polarization was estimated to be less than 20%, in line with previous studies on different molecular dimers. Thus, we decided to employ a computationally cheaper FODFT method to continue our study of the effect of metals and substituents on the electronic couplings for hole transfer. We find that, compared to the non-metallated porphyrins, Ni, Fe and Pt significantly reduce the coupling, while Zn, Ti, Cd and Pd increase it. The effect of substituents was studied on a series of meso-substituted porphyrins (meso-tetrapyridineporphyrin, meso-tetraphenylporphyrin and derivatives) for which we could relate a reduction of the coupling to steric effects that reduce the overlap between the frontier orbitals of the monomers.

Metastases of clinically occult testicular seminoma mimicking primary extragonadal retroperitoneal germ cell tumors.

BACKGROUND: Whether extragonadal germ cell tumors develop primarily in the retroperitoneum or whether they are essentially metastases of a primary testicular tumor has long been debated and remains controversial. PATIENTS AND METHODS: Three patients presenting with apparent primary extragonadal retroperitoneal germ cell tumors are reported. Ipsilateral testicular evaluation was extended with palpation, ultrasonography and finally histological examination. RESULTS: The retroperitoneal extragonadal tumors were found during abdominal MSCT. It was a fortuitous finding in the two first patients.The third patient presented with abdominal pain attributed to necrosis of the large mass which was subsequently firstly drained through endoscopic ultrasound-guided transduodenal puncture. The seminomatous nature of the retroperitoneal tumors was obtained through transduodenal echoendoscopic-guided cytopuncture in the first case, celioscopic resection in the second case and delayed percutaneous CT guided biopsy in the third symptomatic case. The first two patients had a history of cryptorchidism with substantial clinical testicular atrophy; ultrasonography showed microlithiasis and a small intratesticular tumor in the first patient and an hypoechoic but rather homogeneous atrophic testis in the other; orchiectomy confirmed small seminomatous intratesticular tumors in the two cases. The third patient had an atypical hypoechoic area on testicular ultrasound and histopatholgy revealed a burn-out primary tumor. CONCLUSIONS: So-called primary extragonadal retroperitoneal germ cell tumors are extremely rare and should first be considered as metastases of a viable or burned-out testicular cancer until proven otherwise. All ipsilateral testicular abnormalities revealed by the patient's history, clinical examination and mostly by testicular ultrasound must be treated adequately with orchiectomy because they may act as a sanctuary for later tumor growth.

Resonance-enhanced multiphoton ionisation photoelectron spectroscopy of the ClO radical: the C 2 sigma- state

A (2 + 1) one-colour resonance-enhanced multiphoton ionisation study is carried out on the C 2 sigma- state of the ClO radical in the one-photon energy range 29,500-31,250 cm-1. The ClO radical is produced by one-photon photolysis of ClO2 employing 359.2 nm photons derived from a separate laser. In this way a significant concentration of vibrationally excited ClO in its spin-orbit split X 2 pi omega (omega = 3/2 or 1/2) electronic ground state is produced. In addition to mass-resolved excitation spectra, kinetic-energy resolved photoelectron spectra for the X 3 sigma-(v+)<--C 2 sigma-(v' = 3-5) transitions are measured. These transitions are not completely Frank-Condon diagonal, and indicate a decrease in bond length on removal of the Rydberg electron from the C 2 sigma- state. In addition to an unambiguous assignment of the C 2 sigma- state, valuable information is obtained on the degree of vibrational excitation with which the nascent ClO radical is formed in the photolysis of ClO2. Analysis of the photoelectron spectra is supported by Franck-Condon calculations based on potential energy curves either from experimental spectroscopic parameters, or obtained by theoretical ab initio methods.

Adjuvant radiation therapy does not cause urinary incontinence after radical prostatectomy: results of a prospective randomized study.

PURPOSE: We analyzed the potential influence of adjuvant radiotherapy on urinary continence after radical prostatectomy. MATERIALS AND METHODS: A total of 100 patients with N0M0 prostate cancer randomized in a prospective study on postoperative radiotherapy for locally advanced disease (positive surgical margin, capsular perforation and/or seminal vesicle infiltration) were studied. Objective pad weighing tests corroborated by direct personal interviews were used to evaluate urinary continence at regular postoperative intervals. RESULTS: Of the patients 48 received 60 Gy. external radiotherapy with 18 MV photon beams between 12 and 16 weeks postoperatively, and 52 were followed expectantly. Risk factors were similar in both groups. With a mean followup of 24 months, no difference in complete urinary continence was observed. Of the irradiated group 77% and of the surveillance group 83% were totally dry. The fate of the bladder neck had no significant influence on final continence status, although there was a trend for faster recovery when the bladder neck was preserved. CONCLUSIONS: In this prospective randomized study 60 Gy. external radiation therapy administered between 3 and 4 months after radical prostatectomy for pathologically locally advanced prostate cancer had no significant influence on urinary continence.