Interference of plant extracts,phytoestrogens and antioxidants with the MTT tetrazolium assay

The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay is a widely used screening method to measure cell viability and proliferation. When testing the effects of kaempferol on breast cancer cell number (crystal violet staining) and viability (MTT tetrazolium assay) conflicting results were obtained. Cell number decreased but MTT formazan formation increased, suggesting a direct interaction of kaempferol with the MTT tetrazolium reduction. Direct reductive potential was observed in a cell-free system for the presumptive phytoestrogens kaempferol and resveratrol, and extracts of Hypericum perforatum L. and Cimicifuga racemosa L. All agents led to instantaneous dark blue formazan formation in the absence of cells. Additionally, antioxidants such as ascorbic acid, vitamin E and N-acetylcysteine interfered with the MTT tetrazolium assay. When MCF7 and HS578 cells treated with kaempferol were washed before addition of MTT tetrazolium, the direct reduction of dye was reduced significantly. These results indicate that the MTT tetrazolium assay may lead to false positive results when testing natural compounds with intrinsic reductive potential.     

Presence of Chlamydophila psittaci DNA in the central nervous system of a patient with status epilepticus

This study reports an extraordinarily severe and prolonged course of neuroornithosis with generalized status epilepticus as an initial symptom. Direct invasion of the central nervous system by Chlamydophila psittaci was confirmed by the demonstration of specific DNA in the patient's cerebrospinal fluid. The patient recovered slowly under administration of doxycycline.     

Fibroblast growth factor-2 but not Mel-CAM and/or beta3 integrin promotes progression of melanocytes to melanoma

A variety of melanoma-associated antigens have been identified that mediate adhesion, growth, proteolysis, and modulation of immune response. However, the mechanisms by which human normal melanocytes become malignant are not clearly understood. Among the most consistent observations is the up-regulation of fibroblast growth factor-2 (FGF-2) and of the adhesion molecules beta3 integrin and Mel-CAM during melanoma progression. To evaluate the potential role of FGF-2, beta3 integrin and Mel-CAM in melanoma development we overexpressed FGF-2, beta3 integrin and Mel-CAM in normal human melanocytes using replication-deficient adenoviruses as a gene delivery vehicle. Fibroblast growth factor-2 overexpressing melanocytes in monolayer culture displayed cytological atypia. Furthermore, in human skin reconstructs where the physiological milieu is recreated in vitro, FGF-2-overexpressing melanocytes exhibited marked proliferation, upwards migration, cluster formation and type IV collagen expression within the epidermal compartment, simulating early radial growth phase melanoma. In contrast, overexpression of beta3 integrin and/or Mel-CAM in melanocytes did not affect their biological behaviour in human skin reconstructs. The described results of the current and previous studies emphasise the key role of FGF-2 in melanoma development and progression, underscoring the promise of FGF-2 as a target for therapy.     

The Harvest Smart PRePTM system versus the Friadent-Schütze platelet-rich plasma kit

An important reason to improve methods for isolating platelet-rich plasma (PRP) is the potential use of autogenous platelet growth factors. In addition to the Curasan PRP kit (Curasan, Kleinostheim, Germany) and the platelet concentrated collection system (PCCSTM) system, two new methods for the preparation of PRP by the surgeon are now available. This study compared the suitability of these new methods for the preparation of PRP. Whole blood was drawn from 54 healthy donors (33 men and 21 women) aged 23-79 years (38.0 +/- 17.7 years). PRP was prepared from each donor's blood using both the Smart PRePTM system (Harvest Technologies Corporation, Munich, Germany) and the Friadent-Schütze method (PRP kit; Friadent-Schütze, Vienna, Austria). The platelet count in donor whole blood was 276 810 +/- 59 440 /microl. Platelet counts differed significantly between the Smart PRP preparation (1227 890 +/- 312 440 platelets/microl) and the Friadent-Schütze PRP preparation (1440 500 +/- 501 700 platelets/microl) (sign test, P < 0.001). The Smart PRePTM system had a significantly higher collection efficiency (63.4 +/- 7.9%) than the Friadent-Schütze kit (49.6 +/- 13.6%) (sign test, P < 0.001). The leukocyte contents in the two platelet concentrates were similar (Smart PRePTM, 19 261 +/- 8082 platelets/microl; Friadent-Schütze, 21 691 +/- 16 430). Transforming growth factor (TGF)-beta1 and platelet-derived growth factor (PDGF)-AB were higher in the Friadent-Schütze PRP (TGF-beta1, 196.8 +/- 109.6 ng/ml; PDGF-AB, 251.6 +/- 115.4 ng/ml) than in the Smart PRePTM (TGF-beta1, 77.2 +/- 54.8 ng/ml; PDGF-AB, 208 +/- 85.2 ng/ml). The sign test indicated significant differences between the two methods in the concentrations of TGF-beta1 (P < 0.001) and PDGF-AB (P < 0.01). Insulin-like growth factor (IGF)-1 levels in the two PRP preparations were similar (Friadent-Schütze PRP, 72.8 +/- 22.3 ng/ml; Smart PRePTM, 91.4 +/- 21.3 ng/ml). The Smart PRePTM system was superior with respect to ease of handling and preparation time. It also had a significantly higher platelet collection efficiency than the Friadent-Schütze PRePTM kit. The Friadent-Schütze PRP kit offers a slight advantage in the resulting PRP platelet concentration. However, this is easily compensated for in the Smart PRePTM system by reducing the volume of the resulting PRP.     

Parathyroidectomy improves concentration and retentiveness in patients with primary hyperparathyroidism

BACKGROUND: Many patients with primary hyperparathyroidism (PHPT) show symptoms of hypercalcemia syndrome, including psychologic and psychiatric disorders. The aim of this study was to find out whether parathyroidectomy improves cognitive performance with regard to concentration and retentiveness in patients with PHPT. METHODS: . Twenty patients with PHPT underwent psychologic testing preoperatively as well as 6 and 12 weeks postoperatively. Concentration under stress (timing) was proved by the d2-Test of Attention. To evaluate retentiveness, parts of the Wilde Intelligence Test were used. Patients were tested under identical circumstances with regard to time, location, and tester to minimize exterior influences. RESULTS: The patients' concentration enhanced significantly postoperatively (P <.001). The same applied to the total number of items processed (P <.01). Improvement of patients' ability to memorize numbers reached statistical significance when comparing the preoperative with the postoperative result (P =.0396); furthermore, there was a tendency to perform the tests more carefully and accurately (P =.069). CONCLUSIONS: Parathyroidectomy not only betters physical symptoms of PHPT but can also positively influence the patients' cognitive performance. These findings reflect the clinical observation of the patients' improved mental capacity after parathyroidectomy.     

Prioritizing patients for elective surgery: clinical judgement summarized by a Linear Analogue Scale

Background: The New Zealand health reforms have resulted in the requirement that surgeons utilize Clinical Priority Access Criteria (CPAC) to ration patient access to elective surgery. The validity of the tools used as CPAC has been challenged. An alter­native tool, the Linear Analogue Scale (LAS), is therefore used in our institution. Our objectives were to determine the variables that influence the priority score generated using the LAS, and the length of time waited by patients awaiting general surgical procedures. Methods: A cohort of 918 patients who were listed for elective general surgical procedures at Auckland Hospital, Auckland, New Zealand between 1 July 1998 and 31 March 1999 were studied. Patients were given a priority score generated using the LAS. For each patient, the time from assessment until his or her procedure was documented. Linear and logistic regression models were used to investigate variables (age, gender, diagnosis and surgical team) that influence priority score. Cox proportional hazards models were used to investigate variables (priority score, age, gender, and diagnosis) that influence the length of time waited. Results: Graphical presentation showed a pattern of priority scores falling into ‘bands’ for different diagnoses. Diagnosis, and to a lesser extent surgical team, influenced priority score. Survival analysis showed ‘time waited’ to be influenced by priority score, diagnosis, and patient age and gender. Conclusion: The LAS may have a useful role in the difficult sphere of patient prioritization. Its strength lies in its simplicity. Further investigation of reliability and effect on patient outcomes is required.     

Severe ovarian hyperstimulation syndrome and combined intrauterine and tubal pregnancy after in-vitro fertilization and embryo transfer

Ovarian hyperstimulation syndrome (OHSS) and hetero-topic pregnancyare two well recognized entities occurring after in-vitro fertilization(TVF). This is the first reported case of a severe OHSS andcoexistent heterotopic pregnancy after FVF and embryo transfer.Diagnosis of tubal pregnancy was obscured both by stimulatedovaries which prevented accurate ultrasound definition and thecoexistence of an intrauterine pregnancy which accounted forhuman chorionic gonadotropbin (HCG) concentrations and alsofor aggravation of the OHSS. The roles of transvaginal ultrasound,diagnostic laparoscopy and early paracentesis in the managementof this rare complication of assisted reproductive technologiesare discussed.     

Vascular damage as a risk factor for benign prostatic hyperplasia and erectile dysfunction

OBJECTIVE: To assess benign prostatic hyperplasia (BPH) and erectile dysfunction (ED), both considered to be associated with urogenital ageing, in ageing men in a cross-sectional population study, comparing them with healthy controls by using symptom scores and contrast-enhanced colour Doppler ultrasonography (CDUS). PATIENTS, SUBJECTS AND METHODS: Transrectal CDUS and quantitative measurement of colour pixel intensity (CPI) are excellent minimally invasive techniques for assessing normal and pathological blood flow. CDUS was performed using the microbubble-based ultrasound enhancer for evaluating prostate, bladder neck and corpus cavernosum vascularity in young healthy men, men with BPH, and men with severe vascular damage (diabetes mellitus type 2). Resistive index measurements and computer-assisted quantification of CPI were used to objectively evaluate perfusion. The International Prostate Symptom Score (IPSS) and the International Index of Erectile Function (IIEF) were applied to quantify the symptoms. RESULTS: In patients with BPH, perfusion of the transition zone (TZ) of the prostate was significantly lower and the resistive index of the TZ significantly higher (both P < 0.001) than in healthy controls. The perfusion patterns of men with BPH and those who also had severe vascular damage (diabetes mellitus type 2) showed that vascularity in the latter group was lower in the prostatic TZ and the corpora cavernosa. In patients with BPH the IPSS, quality-of-life and IIEF scores were significantly worse than in the control group. Men with concomitant atherosclerosis had even worse symptom scores. CONCLUSION: These results strongly support the hypothesis that age-related impairment of blood supply to the lower urinary tract is important in the development of BPH and ED. Vascular damage may cause chronic ischaemia and thus be a contributing factor in the pathogenesis of BPH and ED.     

The measurement of creep in ultrahigh molecular weight polyethylene: a comparison of conventional versus highly cross-linked polyethylene

Quantification of creep of highly cross-linked polyethylene would enable separation of creep from wear when evaluating femoral head penetration into polyethylene. We compared creep magnitude of a highly cross-linked versus conventional polyethylene in the laboratory. Twelve acetabular liners of each material were tested, 6 of which had a 32-mm inner diameter (ID) and 6 had 28-mm ID. Creep was measured using coordinate measuring machines during loading at 2 Hz without motion to 4 million cycles. Penetration into 32-mm ID conventional liners reached 97 microm versus 107 microm for highly cross-linked material, not significant. Penetration into 28-mm conventional liners was 132 microm versus 155 microm for highly cross-linked material (P = .017). Ninety percent of the creep had occurred by 2.5 million cycles.