Feasibility and construct validity of a novel laparoscopic skills testing and training model

The apprentice–tutor model was useful for training surgeons for many years, but the complexity of surgical technology in the 21st century, especially endoscopic surgery, has exponentially increased the demands for surgical education. Therefore, more and more people now accept that endoscopic surgery, demanding as it requires specific skills, should also be taught outside the operating theatre. Although many systems, including animal models and simulators, have been proposed, an in-house structured and validated method for testing and training laparoscopic skills is missing in gynaecology. We have developed a laparoscopic skills testing and training (LASTT) model and performed two studies evaluating its feasibility and the construct validity of three different exercises (camera navigation, camera navigation and forceps handling, and forceps handling and bi-manual coordination), specifically selected to test and train laparoscopic psychomotor skills (LPS). In the first study, ten experts and 14 novices repeated each exercise between 20 and 30 times. The results demonstrated that the model is useful for testing and training laparoscopic skills. Clear learning curves were observed for both experts and novices, with better scores for the former at the beginning and the end of the study, proving the construct validity of the model. In the second study, 42 experts and 241 novices repeated each exercise three times during skill evaluation workshops organised by the European Academy of Gynaecological Surgery. The results confirmed the construct validity of the model. In conclusion, the LASTT model seems a cost-effective tool for providing an in-house program for continuous training and evaluation of LPS in all surgical disciplines in which laparoscopic procedures are, or might be, performed.     

Radiolabeling, biodistribution, and dosimetry of (123)I-mAb 14C5: a new mAb for radioimmunodetection of tumor growth and metastasis in vivo.

This study reports on the in vitro evaluation, biodistribution, and dosimetry of (123)I-labeled monoclonal antibody (mAb) 14C5, a new antibody-based agent proposed for radioimmunodetection of tumor growth and metastasis in vivo. METHODS: (123)I-mAb 14C5 was prepared by direct iodination and tested for stability in vitro. Binding assays were performed on human SK-BR-3 and HeLa carcinoma cells to investigate the antigen expression, antibody affinity, and kinetics of tracer binding. For the biodistribution and dosimetry study, 3- to 4-wk-old NMRI mice were injected intravenously with (123)I-mAb 14C5 (148.0 +/- 7.4 kBq per mouse) and killed at preset time intervals. Organs, blood, urine, and feces were counted for radioactivity uptake, and the data were expressed as the percentage injected dose per gram tissue (%ID/g tissue) or %ID. The MIRDOSE3.0 program was applied to extrapolate the estimated absorbed radiation doses for various organs to the human reference adult. RESULTS: (123)I-mAb 14C5 was obtained in radiochemical yields of 85.0% +/- 2.5% and radiochemical purities were >97%. The iodinated antibody demonstrated good in vitro stability with 93.6% +/- 0.1% of (123)I-mAb 14C5 remaining intact at 24 h after radiolabeling. (123)I-mAb 14C5 bound to SK-BR-3 cells (dissociation constant [K(d)] approximately 0.85 +/- 0.17 nmol/L) and HeLa cells (K(d) approximately 1.71 +/- 0.17 nmol/L) with nanomolar affinity and high specificity, whereas both cell types exhibited a high CA14C5 antigen expression (maximum number of binding sites [B(max)] = 40.6 +/- 5.2 and 57.1 +/- 9.6 pmol/L, respectively). In mice, (123)I-mAb 14C5 accumulated primarily in lungs (20.4 %ID/g), liver (15.1 %ID/g), and kidneys (11.1 %ID/g) within 5 min after injection. A delayed uptake was observed in stomach (12.8 %ID/g) and urinary bladder (8.7 %ID/g) at 3 and 6 h, respectively, after injection. Radioactivity clearance was predominantly urinary, with 44.9 +/- 4.5 %ID excreted during the initial 48 h after administration (cumulative amount). The highest absorbed radiation doses determined for the human reference adult were received by the urinary bladder wall (0.1200-0.1210 mGy/MBq), liver (0.0137-0.0274 mGy/MBq), uterus (0.0196-0.0207 mGy/MBq), and lower large intestine wall (0.0139-0.0258 mGy/MBq). The average effective dose resulting from a single (123)I-mAb 14C5 injection was estimated to be 0.017-0.022 mSv/MBq. CONCLUSION: (123)I-mAb 14C5 shows good in vitro biologic activity and favorable biodistribution properties for imaging carcinomas of different origin and provides an acceptable radiation dose to the patient.     

Infusional 5-fluorouracil and mitomycin C: an effective regimen in the treatment of advanced gastric cancer

BACKGROUND: Weekly infusional 5-fluorouracil (5-FU) and folinic acid (FA) as part of multi-drug chemotherapy regimens in advanced gastric cancer (AGC) has shown to be effective with low toxicity. The present analysis was carried out to evaluate the safety and efficacy of 5-FU/FA in combination with 3-weekly mitomycin C (MMC) in patients with advanced gastric cancer. PATIENTS AND METHODS: A total of 28 patients with AGC were analysed (first line n=23). They received weekly 24-h 5-FU 2,600 mg/m2 preceded by 2-h FA 500 mg/m2 for 6 weeks followed by a two week rest period. Bolus MMC 10 mg/m2 was applied on days 1 and 22. Patient characteristics were: m/f 17/11; median age 67 years (43-79). The most common metastatic sites were liver and peritoneum (n=12, respectively). RESULTS: A median of 3 and a total of 91 cycles were administered. Mean dose intensity in cycle I was: 5-FU 86%, MMC 87%. Responses were observed in 43%, no change was seen in 29% of the patients. Median overall survival was 9.7 months (10.7 months for patients treated first line). Non-haematological toxicities (NCI CTC grades 3 and 4) were observed in 2 patients, leukopenia and thrombocytopenia grades 3/4 were observed in 50 and 25% of the patients, respectively. CONCLUSIONS: Infusional 5-FU/FA plus MMC may safely be used in patients with AGC in the routine clinical setting. This regimen yields response rates and survival data comparable to platinum-based regimen.     

In vivo evaluation of [123I]-4-iodo-N-(4-(4-(2-methoxyphenyl)-piperazin-1-yl)butyl)-benzamide: a potential sigma receptor ligand for SPECT studies

In this study, in vivo evaluation in mice and rabbits of [123I]-4-iodo-N-(4-(4-(2-methoxyphenyl)-piperazin-1-yl)butyl)-benzamide ([123I]-BPB), a potential radioligand for visualisation of the sigma receptor by single photon emission computed tomography (SPECT), is reported. The compound possesses appropriate lipophilicity (log P=2.2) and binds sigma-1 and sigma-2 receptors (pKi=6.51 and 6.79, respectively). In mice, this new radioiodinated tracer exhibited high brain uptake (4.99% ID/g tissue at 10 min postinjection) and saturable binding (3.06% ID/g tissue at 10 min postinjection) as determined by pretreatment with unlabeled [123I]-BPB. A metabolite study demonstrated no (less than 5%) labeled metabolites in the brain. In rabbits, regional brain distribution was investigated and the tracer displayed high, homogeneous central nervous system uptake. Selectivity was assessed by competition experiments with known sigma ligands. Metabolite analysis showed no (less than 8%) labeled metabolites in the rabbit brain. In conclusion, our findings indicate that [123I]-BPB is not a suitable tracer for visualisation of D3 receptors while its potential for sigma receptor imaging is severely hampered by its affinity for dopamine receptors.     

In vivo apoptosis detection with radioiodinated Annexin V in LoVo tumour-bearing mice following Tipifarnib (Zarnestra, R115777) farnesyltransferase inhibitor therapy

In this paper, the use of (123)I-Annexin V for the detection of farnesyltransferase inhibitor (FTI)-induced apoptosis in tumour-bearing athymic mice is described. In vitro binding assays on LoVo cells show time- and dosage-dependent (125)I-Annexin V binding upon treatment with Tipifarnib (Zarnestra, R115777), a selective and potent FTI. In vivo experiments using planar gamma scintigraphy on LoVo inoculated mice show a 40% increased (123)I-Annexin V uptake 8 h after a single oral administration of 100 mg/kg Tipifarnib in 20% beta-cyclodextrin in 0.1 M HCl, as well as after 3 days of twice daily treatments with the same dose. Ex vivo TUNEL assays, detecting end-stage apoptotic cells, correlate significantly with both in vitro and in vivo results. The percentage of necrosis is also increased by Tipifarnib treatment, but is too low to interfere with the (123)I-Annexin V uptake. It can be concluded that (123)I-Annexin V can be used to monitor Tipifarnib-induced apoptosis in LoVo xenograft tumours in athymic mice. Future applications might include the early prediction of FTI response and the selection of FTI-sensitive patients very shortly after treatment initiation. Subsequently, such patients would greatly benefit from a noninvasive and fast therapy evaluation.     

In an observational study elderly patients had an increased risk of falling due to home hazards

OBJECTIVE: The objective of this study was to explore the relationship between home hazards and the incidence of falls in the oldest old population. STUDY DESIGN AND SETTING: The Leiden 85-plus Study is a population-based study of all 85-year-old inhabitants of Leiden in the birth-cohort 1912-1914. Participants and general practitioners were interviewed at baseline and annually there after. We analyzed the incidence of falling in the first year dependent on the presence of home hazards at baseline. There were no exclusion criteria other than the inability to walk alone. RESULTS: During the 1-year follow-up, 44% of the participants experienced one or more falls. Participants without preceding falls (n=246) had a 4-fold risk for falls in the presence of six or seven home hazards (relative risk 3.58, 95% confidence interval 1.75-5.05) compared with those without home hazards. Participants with preceding falls (n=234) had no increased risk of falls with increasing numbers of home hazards, although they had a higher risk to fall. The data confirmed the known increased risk for falls in participants with physical impairments. CONCLUSION: We conclude that participants without a history of preceding falls have an increased risk of falling due to the presence of home hazards.     

Homocysteine, vitamin B-12, and folic acid and the risk of cognitive decline in old age: the Leiden 85-Plus study

BACKGROUND: High concentrations of homocysteine and low concentrations of vitamin B-12 and folic acid are frequently observed in subjects with dementia. OBJECTIVE: We assessed whether serum concentrations of homocysteine, vitamin B-12, or folic acid predict cognitive decline in old age. DESIGN: This was a prospective, population-based, longitudinal study of 599 subjects (Leiden 85-Plus Study, Netherlands). The subjects were administered a battery of cognitive tests (including the Mini Mental State Examination, the Stroop test, a letter digit coding test, and a word recall test) at 85 y of age and yearly thereafter until 89 y of age. Serum concentrations of homocysteine, vitamin B-12, and folic acid were measured at 85 and 89 y of age. Cross-sectional associations between serum concentrations and cognition were assessed at 85 and 89 y of age. The association between baseline serum concentrations and subsequent longitudinal cognitive decline was assessed with the use of mixed linear models. RESULTS: In the cross-sectional analyses, serum concentrations of homocysteine and folic acid were significantly associated with cognitive performance, but serum concentrations of vitamin B-12 were not. In the longitudinal analyses, there were no significant associations of serum concentrations of homocysteine, vitamin B-12, or folic acid with rate of cognitive decline. CONCLUSIONS: Elevated serum concentrations of homocysteine and reduced folic acid are associated with cognitive impairment in elderly persons but do not predict an increased rate of cognitive decline. The association of high serum concentrations of homocysteine and low folic acid with cognitive impairment in old age is likely to be a consequence of disease and not a contributory cause.