Primary Hyperparathyroidism Patients with Positive Preoperative Sestamibi Scan and Negative Ultrasound Are More Likely to Have Posteriorly Located Upper Gland Adenomas (PLUGs)

BackgroundStandard preoperative imaging for primary hyperparathyroidism usually includes sestamibi scanning (MIBI) and ultrasound (US). In a subset of patients with a positive MIBI and a negative US, we hypothesize that the parathyroid adenomas are more likely to be located posteriorly in the neck, where anatomically they are more difficult to detect by US.MethodsWe retrospectively reviewed the records of 661 patients treated for primary hyperparathyroidism between 2004 and 2009 at a tertiary referral center. We included patients who for their first operation had a MIBI that localized a single lesion in the neck and an US that found no parathyroid adenoma. We excluded patients with persistent or recurrent hyperparathyroidism, and patients with MIBIs that were negative, that had more than one positive focus, or that had foci outside of the neck. Sixty-six cases were included in the final analysis.ResultsA total of 54 patients (83%) had a single adenoma, 4 (6%) had double adenomas, and 7 (11%) had hyperplasia. Thirty-three patients (51%) had a single upper gland adenoma; 19 of these (58%) were posteriorly located upper gland adenomas (PLUGs). PLUGs occurred more often on the right side than on the left (P = 0.048, Fisher's test). PLUGs were also larger than other single adenomas (mean 1.85 vs. 1.48 cm, P = 0.021, t-test). Seventy-six percent of patients successfully underwent a unilateral or focused exploration. Six patients (9%) had persistent disease, which is double our group's overall average (4-5%).ConclusionsPrimary hyperparathyroid patients with preoperative positive MIBI and negative US are more likely to have PLUGs

Evaluation of Mediterranean wastes: A case study for aegean region agro-industrial wastes

Being a part of the Mediterranean basin the Aegean Region of Turkey contributes immensely to the Turkish economy with its agro-industrial infrastructure and consequently enormous amounts of agricultural wastes and surpluses are produced annually. Presently, these materials are very rarely reutilized. The fact that agro-industrial wastes contain economically valuable or microbially metabolizable components enable them to be converted to high value added products through biotechnological methods. The objective of this study was to develop a data base and to determine the sources, quantities and qualities, the physical, chemical and biological characteristics of the Region's agro-industrial wastes

" Effect of light intensity and the light: Dark cycles on the long term hydrogen production of Chlamydomonas reinhardtii by batch cultures"

The photomixotrophic hydrogen production was investigated in sulfur deprived Chlamydomonas reinhardtii cultures. The cultures were exposed to continuous illumination of various light intensities in 27-day batches. Light intensity of 70 × 2 µE m-2 s-1 was selected for hydrogen production. Subsequent experiments involving 27-day long light:dark cycles were conducted at the selected light intensity. The cycles consisted of hour divisions (h:h; 18:6, 14:10, 12:12) or minute divisions (min:min; 45:15, 35:25, 30:30). The results showed an adverse effect of the light:dark cycles on hydrogen production. All experiments, irrespective of the type of illumination indicated that cultures needed a lag phase for production and the highest hydrogen production was obtained during first 7-10 days of production reaching a peak in the first 5 days. © 2010 Elsevier Ltd

Photo-bioproduction of hydrogen by Chlamydomonas reinhardtii using a semi-continuous process regime

Photo-bioproduction of hydrogen by using green algae, Chlamydomonas reinhardtii, was investigated in batch and semi-continuous process regimes, in a continuous stirred type photobioreactor. Batch cultivation was carried out for 35 days which was one of the longest cited in literature. Total hydrogen production with batch culture reached 316 ml. The observations from the batch culture provided useful data about the production process. Three important observations were made from the batch cultivation. One was the requirement of a 2 day-lag time for the start of the hydrogen production. Second one was the fact that the maximum hydrogen production is reached at around day 4. Third one was the decline of hydrogen production after a week. Semi-continuous regime was preferred rather than a continuous one based on these data. Semi-continuous cultivation was continued for 127 days yielding a total hydrogen production of 1108 ml. In the semi-continuous process, the effects of parameters such as dilution ratio, dilution frequency and fresh medium addition were studied. The range of these parameters was also decided, based on the batch cultivation data. Each experiment testing for different parameters lasted for 7 days and thus five consecutive sets were completed in 35 days. The results showed a direct correlation between the amount and frequency of dilution and hydrogen production. Semi-continuous regime gave the opportunity of dividing the continuous production in consecutive batches and the process was in good relation with batch regime. © 2009 Professor T. Nejat Veziroglu