Prostate cancer detection among readers with different degree of experience using ultra-high b-value diffusion-weighted Imaging: Is a non-contrast protocol sufficient to detect significant cancer?

AIM: To evaluate the accuracy of a T2-weighted (T2w) - and a parallel transmit zoomed b = 2000 s/mm2 (b2000) - diffusion-weighted imaging sequence among three readers with different degrees of experience for prostate cancer (Pca) detection. METHODS: Ninety-three patients with suspected Pca were enrolled. For b2000 a two-dimensional spatially-selective RF pulse using an echo-planar transmit trajectory was applied, and the field of view (FOV) was reduced to one-third. All three readers (Reader A: 7, B 4 and C <1 years of experience in prostate MRI) independently evaluated b2000 with regard to the presence of suspicious lesions that displayed increased signal. The results were compared to histopathology obtained by real-time MR/ultrasound fusion and systematic biopsy. RESULTS: In 62 patients Pca was confirmed. One significant Pca (Gleason score (GS) 7b) was missed by Reader C. Overall, sensitivity/specificity/positive predictive value/negative predictive value were 90/71/86/79% for Reader A, 87/84/92/76% for Reader B and 85/74/87/72% for Reader C, respectively. Detection rates for significant Pca (GS >7a) were 100/100/94% for Readers A/B/C, respectively. Inter-reader agreement was generally good (Kappa A/B: 0.8; A/C: 0.82; B/C: 0.74). CONCLUSION: B2000 in combination with a T2w could be useful to detect clinically significant Pca. KEY POINTS: • Significant prostate cancer using zoomed ultra-high b-value DWI was detected. • Diagnostic performance among readers with different degrees of experience was good. • mp- MRI of the prostate using a comprehensive non-contrast protocol is clinically feasible.

Determination of some physiological factors affecting xylanase production from Trichoderma harzianum 1073 D3.

In this study, different Trichoderma strains were tested and Trichoderma harzianum 1073 D3 was found to be the most potent xylanase producer. Then some cultural parameters, namely, incubation time, substrate concentration, initial culture pH and temperature were optimized in order to increase xylanase production from Trichoderma harzianum 1073 D3. The optimum incubation time was found to be 13 days. It was concluded that 1% xylan concentration is suitable for high xylanase production rate. The optimum temperature and pH were found to be 30 degrees C and 7, respectively. Also, it was determined that agitation during growth was suitable for efficient production.

Production of gibberellic acid by Aspergillus niger using some food industry wastes.

The production of gibberellic acid by Aspergillus niger and the possibility of utilizing food industry waste and residues as the sources of carbon in media were investigated. Media prepared from molasses, vinasse, whey, sugar-beet waste and fruit pomace were used and GA3 yields were found in concentrations 310, 273.14, 120, 73, 118.13 mg/l in such media, respectively. It was observed that food industry wastes can be used as cheap sources of carbon for gibberellic acid production by Aspergillus niger.

[The isolation, classification and some physiological properties of a protease-producing bacterium]. / Proteaz içeren bakterinin izolasyonu, siniflandirilmasi ve bazi fizyolojik özelliklerinin saptanmasi.

A proteolytic bacterium was isolated from specimen collected from soil. The protease producing bacterium showed optimal growth in media with neutral pH and when incubated at 30 degrees C aerobically. According to the classification results, the gram (+), sporulating bacillus was a Bacillus genus member. Also some physiological properties of the isolated bacterium was determined.

[Effect of physiological factors on biosynthesis of urease in Bacillus spp]. / Bacillus spp.'de üreaz sentezini etkileyen bazi fizyolojik faktörler.

In this study, urea was shown to be the inducer of the urease enzyme of the soil isolate Bacillus spp. The extracellular urease enzyme production was repressed in UGT cultures containing ammonia, ammonium chloride or tryptophane and in nutrient broth cultures. The optimal urease production culture conditions were determined as pH: 7.0, 30 degrees C and 150 rpm.

[Effects of some physiologic factors on Bacillus sp. urease activity]. / Bacillus sp. üreaz aktivitesine etkili bazi fizyolojik faktörler.

In this study, culture supernatant of Bacillus sp. has been used as crude enzyme source. It has been determined that 1% urea is the optimal substrate concentration for maximal urease activity. On the other hand, Bacillus sp. urease showed its maximal activity at pH:7.0-8.0, 30 degrees C. 50 minutes of incubation has been found to be the most suitable incubation period. The activity of the enzyme showed a 36% decrease when stored at +4 degrees C for a month.

[Isolation of a moderately halophilic bacterium from Salt Lake, Turkey]. / Ilimli tuzcul karakterli bir bakterinin Tuz Gölünden (Türkiye) izolasyonu.

A moderate halophilic bacterium was isolated from Salt Lake, Turkey. Dundas' complex medium was used for further investigations. The bacterium showed optimal growth in medium containing 8% NaCl. Growth was also detected in media with 0, 5, 12.5, 20 and 25 (%) NaCl.

[The fungal flora of Ankara air in January 1972 and 1974 and its relationship to allergic diseases]. / 1972 ve 1974 ocak aylarinda ankara'nin çesitli semtlerinde havanin küf ve maya florasindaki degisiklik ve bunun allerjik hastaliklar yönünden önemi

The fungal flora of the air in Ankara was searched during first week of January 1972 and 1974. Different areas of the city were chosen for investigation. The central and outskirt areas showed different patterns of fungal flora during January 1972 and January 1974. In the central areas there was a remarkable decrease in yeast flora between the two years. However, mould flora was increased in some extent. No notable difference could be detected in outskirt areas. Penicillium and Aspergillus species were isolated most frequently. It is concluded that this flora was influenced by heavy pollution of the air in Ankara. This pollution is caused mainly by: (1) Heating systems with crude coal and oil, (2) Heavy motor traffic, (3) Geographical situation of the city, cup-shaped land with poor air draughts.