Biochemical Recurrence of Prostate Cancer: Initial Results with [18F]PSMA-1007 PET/CT

Biochemical recurrence (BCR) is a concern for prostate cancer patients after local treatment. ⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA) ligands have significantly improved prostate cancer imaging. However, several ¹⁸F-labeled ligands that were developed as fluorinated tracers might present advantages. In this study, we analyzed the potential of ¹⁸F-PSMA-1007 in patients with BCR. Methods: Twelve patients with BCR after local treatment underwent PET/CT scans 1 and 3 h after injection of ¹⁸F-PSMA-1007. Results:¹⁸F-PSMA-1007 PET/CT detected lesions in 9 of 12 patients (75%). A significant difference was observed when comparing the tracer uptake in ¹⁸F-PSMA-1007-positive lesions 1 and 3 h after injection (median SUV_max, 7.00 vs. 11.34; P < 0.001; n = 76). Forty-four (88%) of 50 ¹⁸F-PSMA-1007-positive lymph nodes had a short-axis diameter of less than 8 mm. Conclusion: In this pilot study, ¹⁸F-PSMA-1007 PET/CT presented high potential for localization of recurrent disease in prostate cancer patients with BCR.

Rhinomanometric reference intervals for normal total nasal airflow resistance

BACKGROUND

Reference intervals (RIs) or mean values for normal total nasal airflow resistance are essential for the diagnosis of nasal obstruction. Data relating to nasal airflow are not standardised, and valid and reliable RIs do not exist for the time being. This meta-analysis aimed to determine such “standard” 95%-RIs.

METHODOLOGY

Research of related literature listed in Medline, Embase, Cochrane, and Web of Science databases.

RESULTS

Airflow resistance data were gathered from 38 studies using active anterior rhinomanometry at a differential pressure of 150Pa to examine patients under congested and decongested mucosal conditions. In the meta-analysis overall values and RIs for normal total nasal airflow resistance under congested nasal mucosal conditions were calculated for all subjects at 0.25Pa/cm3/s (95%-RI 0.10-0.40Pa/cm3/s), adults regardless of gender at 0.25Pa/cm3/s (95%-RI 0.12-0.38Pa/cm3/s), men at 0.24Pa/cm3/s (95%-RI 0.09-0.39Pa/cm3/s), and women at 0.26Pa/cm3/s (95%-RI 0.08-0.44Pa/cm3/s). Asian, African and Caucasian ethnic groups exhibited rising airflow resistance mean values: 0.23Pa/cm3/s (95%-RI 0.08-0.39Pa/cm3/s), 0.25Pa/cm3/s (95%-RI 0.11-0.38Pa/cm3/s) and 0.26Pa/cm3/s (95%-RI 0.13-0.38Pa/cm3/s), respectively. Lower overall mean values resulted under decongested nasal mucosal conditions.

CONCLUSION

The reference intervals and mean values ascertained in this meta-analysis improve the diagnosis of nasal obstruction and may represent a useful supplement in existing guidelines for the standardisation of rhinomanometric measurements.

[Surgical treatment of aortic valve stenosis]

Surgical aortic valve replacement still represents the gold standard in patients with severe symptomatic aortic valve stenosis. In addition to conventional aortic valve replacement by mechanical or biological prostheses via a median sternotomy, novel approaches including minimally invasive strategies and new devices, such as so-called rapid deployment prostheses, are becoming increasingly more established. Autologous replacement strategies including the Ross and the Ozaki procedures have evolved into reliable options at selected centers of excellence. These novel treatment approaches in aortic valve surgery result in excellent short and long-term outcomes with a reduction of procedure-related complications. Taken together, these modern surgical replacement strategies enable a personalized surgical treatment in patients with aortic valve stenosis, which are tailored to the individual patient.

Can pre-operative contrast-enhanced dynamic MR imaging for prostate cancer predict microvessel density in prostatectomy specimens?

The aim of this study was to correlate quantitative dynamic contrast-enhanced MRI (DCE MRI) parameters with microvessel density (MVD) in prostate carcinoma. Twenty-eight patients with biopsy-proven prostate carcinoma were examined by endorectal MRI including multiplanar T2- and T1-weighted spin-echo and dynamic T1-weighted turbo-FLASH MRI during and after intravenous Gd-DTPA administration. Microvessels were stained on surgical specimens using a CD31 monoclonal antibody. The MVD was quantified in hot spots by counting (MVC) and determining the area fraction by morphometry (MVAF). The DCE MRI data were analyzed using an open pharmacokinetic two-compartment model. In corresponding anatomic locations the time shift (Deltat) between the beginning of signal enhancement of cancer and adjacent normal prostatic tissue, the degree of contrast enhancement and the contrast exchange rate constant (k21) were calculated. The MVC and MVAF were elevated in carcinoma (p<0.001 and p=0.002, respectively) and correlated to k21 (r=0.62, p<0.001 and r=0.80, p<0.001, respectively). k21-values of carcinoma were significantly higher compared with normal peripheral but not central zone tissue. Deltat was longer in high compared with low-grade tumors (p=0.025). The DCE MRI can provide important information about individual MVD in prostate cancer, which may be helpful for guiding biopsy and assessing individual prognosis.

Studies on the prenatal toxicity of N,N-dimethylformamide in mice, rats and rabbits

Prenatal toxicity studies with N,N-dimethylformamide (DMF) in rabbits, rats and mice were carried out using the oral (gavage), dermal, inhalation and ip injection routes of administration. Administration of DMF by gavage led to an increase in malformations in rats and mice in the absence of overt maternal toxicity. The lowest-observable-effect level was 182 mg/kg body weight/day in mice and 166 mg/kg body weight/day in rats. After dermal administration a dose-dependent incidence of teratogenicity was observed in rats at 94-944 mg/kg/body weight/day in the absence of overt maternal toxicity. In rabbits dermal administration led to a steeper increase in the dose-response relationship and at 400 mg/kg body weight/day to a clear teratogenic effect in the presence of slight maternal toxicity. The 200 mg/kg body weight/day dose appeared to be the no-adverse-effect level. Inhalation in rats caused foetotoxicity and embryolethality at 287 ppm. A clear teratogenic effect was shown in rabbits at 450 ppm and a marginal effect at 150 ppm. The no-effect level for does and foetuses was 50 ppm. Ip injection in mice caused clear teratogenicity at 944 mg/kg body weight/day and slight embryotoxicity at 378 mg/kg body weight/day. The rabbit appears to be more sensitive than the rat to DMF-related prenatal toxicity and should, therefore, be used as the basis for the evaluation of teratogenic risk in humans.

Developmental toxicity in rats after inhalation exposure of di-2-ethylhexylphthalate (DEHP)

Di-2-ethylhexylphthalate (DEHP) was investigated in Wistar rats for developmental toxicity after head-nose exposure to aerosol concentrations of 0, 0.01, 0.05 and 0.3 mg/l for 6 h per day from gestation day 6 through 15. A range finding study revealed peroxisome proliferation in the liver of the dams throughout exposure levels of 0.2, 0.5 and 1.0 mg/l with an increasing trend. 0.3 mg/l was therefore regarded as an exposure level leading to peroxisome proliferation as a marker for maternal effects. All concentrations were tolerated without clinical signs of maternal toxicity. The fetuses of 20 animals per exposure group were investigated for structural defects. Five additional animals per group were allowed to litter and the offsprings were raised and observed for postnatal signs of toxicity. No significant developmental toxicity or changes in the postnatal physical development were observed. DEHP is assumed not to exhibit developmental toxicity under the experimental conditions employed.

Prenatal toxicity of 2-methoxypropylacetate-1 in rats and rabbits

2-Methoxypropylacetate-1 was investigated in Wistar rats and Himalayan rabbits for embryotoxic potential. Rats after inhalation exposure to 0, 0.6, 3.0, or 14.9 mg/liter (approximately 0, 110, 550, or 2700 ppm, respectively) for 6 hr per day from gestation Days 6 through 15 exhibited some degree of maternal toxicity at 2700 and 550 ppm. At 2700 ppm an increase of skeletal anomalies of the thoracic vertebrae among the fetuses was observed and interpreted as an exposure-related slight teratogenic effect. In Himalayan rabbits exposed via inhalation to 0, 0.2, 0.8, or 3.0 mg/liter (approximately 0, 36, 145, or 550 ppm, respectively) for 6 hr per day from gestation Days 6 through 18 teratogenicity was much more pronounced: at 550 ppm, in the absence of clear maternal toxicity, the fetuses of all litters showed severe malformations. No maternal or fetal effects were observed at 145 and 36 ppm. Dermal application of 1000 and 2000 mg/kg to Himalayan rabbits from gestation Days 6 through 18 failed to produce maternal or fetal toxicity.

Identification and assessment of the effects of chemicals on reproduction and development (reproductive toxicology)

Most studies for determining the reproductive toxicity of a chemical have to be conducted with whole animals. Test procedures used to investigate parts or the whole of the reproductive cycle are described in current guidelines. Other techniques, such as in vitro methods, and those for investigating specific events in the cycle, are under development. Epidemiological studies can give valuable information, although they are difficult to perform and interpret in practice. There is a need for more epidemiological studies of exposed populations and for recording and quantifying the concentrations of chemicals to which such populations are exposed. It is suggested that animal experiments should be programmed in a stepwise manner, and should take into account effects seen in previous toxicity studies. The programme of tests for determining reproductive toxic potential should be established on a case-by-case basis, since many factors will influence the choice of studies and the sequence in which they should be performed.

An embryotoxicity study of the fungicide tridemorph and its commercial formulation Calixin

Tridemorph (N-tridecyl-2,6-dimethylmorpholine), the active ingredient of the commercially formulated fungicide Calixin, is a teratogen in rats and mice. The no-effect level for embryotoxic effects was 27.5 mg/kg for mice and 20.6 mg/kg for rats. By contrast, when Calixin, which contains 83% tridemorph, was administered orally at dose levels of 0.156, 0.722, and 3.909 mg/kg, no embryotoxic effects were observed in two strains of rats. Our extensive investigations, carried out under exposure conditions resembling as closely as possible those reported in another study, did not reproduce the previous findings of teratogenicity of Calixin.

n-Butyl acrylate: prenatal inhalation toxicity in the rat

n-Butyl acrylate was examined for its prenatal toxicity in Sprague-Dawley rats. Inseminated rats were exposed to concentrations of 0, 25, 135 and 250 ppm for a duration of 6 hours per day from the 6th to 15th day post coitum. Subsequently the animals were held to the 20th day post coitum. During the inhalation period concentrations of 135 and 250 ppm n-butyl acrylate led to maternal toxicity (delayed body weight gain depending on the concentration, clinical signs of irritation). At the end of the exposure period the signs subsided. The same concentrations induced embryolethality (increased number of dead implantations depending on the concentration). 25 ppm of n-butyl acrylate did not lead to maternal toxicity or embryolethality. Under the conditions chosen, a teratogenic effect of the test substance was not detected at any concentration.

Absence of povidone-iodine-induced mutagenicity in mice and hamsters

Povidone-iodine USP was tested for mutagenicity in mice by the dominant lethal assay or micronucleus test and in Chinese hamsters by the bone marrow test. None of the three tests revealed any evidence of mutagenic effect.