Pituitary adenomas: results of 684 surgically treated patients and review of the literature

BACKGROUND: The outcome of patients with pituitary adenomas who were treated surgically with or without postoperative radiotherapy was analyzed. The purpose of this study was to determine the factors that strongly influence (A) tumor control, (B) the efficacy of surgery, and (C) radiotherapy based on the hormonal activity of adenomas and its invasion characteristics. METHODS: Between 1982-1996, 684 patients with the diagnosis of pituitary adenoma were operated on. The mean age was 38 years and the mean follow-up time was 40.5 months. A total of 516 patients who were followed for more than 1 year were studied to analyze the effect of treatment modalities and invasion characteristics on tumor control. There were 297 patients with prolactinomas, 118 patients with somatotropinomas, 45 with corticotropinomas, 17 with mixed adenomas, two with thyrotropinomas, and 205 with null cell adenomas. All patients were classified according to Hardy's modified radiological classification scheme and analyzed in invasive and noninvasive groups individually based on this classification system. In the early postoperative period, 230 of these patients were given conventional radiotherapy with a mean dose of 4400 cGy. The following factors were analyzed for prognostic significance in tumor control: the effects of surgery and radiotherapy based on tumor types and invasion characteristics, the existence of histologically proven invasion of the dura mater overlying the sellar floor, and the early results of topical bromocriptine application in macroprolactinoma patients. RESULTS: Overall surgical complications and mortality rate were similar to those of large series reported in the literature. Except for the invasive somatotropinomas and null cell adenomas, statistical analysis demonstrated the ineffectiveness of radiotherapy on tumor control. We did not detect any positive correlation between the recurrence rate and mean recurrence time or dural invasion of the sellar floor. Topical bromocriptine application seemed to improve tumor control in 21 selected macroprolactinoma patients. CONCLUSION: Conventional radiotherapy is not as effective as expected, considering its adverse effects. The increased side effects of radiotherapy in cases with supra-parasellar extension, especially to the optic pathway and hypothalamus, limit its benefits, which could be demonstrated only in invasive somatotropinomas and null cell adenomas. In contrast with our current beliefs, tumoral infiltration of the sellar dura mater is not a prognostic factor for recurrence and therefore should not be a criterion for radiotherapy after surgery. Topical application of bromocriptine into the sellar cavity after tumor removal seems to provide superior results compared with the conventional treatment modalities.     

The contracting and relaxing responses of human internal mammary artery grafts harvested by two different methods

Perioperative spasm of internal mammary artery is a common experience in coronary artery bypass grafting. Many techniques were described of harvesting the internal mammary artery to prevent vasospasm. We investigated the comparison of the contracting and relaxing responses of human internal mammary artery grafts harvested by two different methods. Patients were divided into two groups depending on the harvesting technique. In the first and second groups arteries were harvested by classical and carbon dioxide insufflation techniques, respectively. In both groups, endothelial function of arteries was assessed by precontracting the rings with phenylephrine (10(-5)M) and dilatating them by cumulative acetylcholine (10(-8) to 10(-5)M) concentrations. Cumulative concentration-response curves for phenylephrine (10(-8) to 10(-4)M), noradrenaline (10(-9) to 10(-4)M), and 5-hydroxytryptamine (10(-9) to 10(-4)M) were obtained in all groups. Endothelial integrity of arteries were histopathologically evaluated. In both groups, acetylcholine caused concentration-dependent relaxations in rings precontracted with phenylephrine (10(-5)M). In arteries harvested by carbon dioxide insufflation technique, acetylcholine caused significantly higher relaxations compared to the rings obtained by classical technique (p<0.05). In all rings of study groups, phenylephrine, noradrenaline and 5-hydroxytryptamine caused concentration-dependent contractions. There was not any significant difference in concentration-dependent responses of these contracting pharmacological agents between the groups. Histopathological evaluation revealed no major arterial damage in both groups. Carbon dioxide insufflation technique does seem not only to protect the integrity of the endothelium and the whole vessel, but also prevent the possible vasospasm of the internal mammary artery segments.     

Effect of nitric oxide synthase inhibitor on experimentally induced burn wounds

BACKGROUND: Nitric oxide (NO) may have an important role in the healing of burn wounds. This study investigated the effect of NO on experimentally induced burn wounds by preventing NO synthesis. METHODS: A total of 40 mice weighing 25 to 30 g were used in this study. The shaved skin on the back of the mice was immersed in 100 degrees C water for 10 seconds to achieve a partial-thickness scald burn. The mice were divided into two groups of 20. In group I (control group), 17.5 mg/kg of serum physiologic (placebo) was injected intraperitoneally two times a day for 15 days. In group II (study group), 17.5 mg/kg of aminoguanidine (NO synthase inhibitor) was injected intraperitoneally two times a day for 15 days. On day 15 of the burn, the animals were killed and the burn areas were investigated histologically. Histologic changes such as epithelial proliferation, abscess, collagen, and granulation tissue were evaluated. RESULTS: Epithelial proliferation, formation of collagen, and granulation tissue with rich capillaries observed in the control group were statically significantly higher than those observed in the study group (z = -2.022, p < 0.05; z = -2.02, p < 0.05; and z = -2.022, p < 0.05; respectively). CONCLUSION: We concluded that healing of the burn wound is delayed by preventing NO synthesis.     

An unusual case of epigastric heteropagus: parasite with a rudimentary heart

Parasitic or heterotopic conjoined twins are exceedingly rare, and these cases are referred to as "heteropagus" when there is a parasitic attachment in a nonduplicated fashion to any portion of the body. Epigastric heteropagus twinning refers to the attachment of the parasite to the epigastric region of the autosite. An unusual epigastric heteropagus case is presented with a rudimentary cardiopulmonary and also nearly complete gastrointestinal and genitourinary system of the parasite, and an organogenetic and vascular status of the previously reported cases are reviewed. The current case might be unique for the parasite having a cardiopulmonary development--although rudimentary--and this might be the reason that it has more complete organogenesis than the cases that have been presented previously in the literature.     

The effect of anticoagulation on antenatal ultrasound findings in pregnant women with thrombophilia.

OBJECTIVE: To assess whether treatment with heparin alters ultrasound findings in pregnant women with inherited thrombophilia. METHODS: This was a retrospective study of a cohort of patients referred for pregnancy complications who were found to have genetic thrombophilia. Ultrasounds were reviewed in treated and untreated pregnancies for the presence of growth restriction, oligohydramnios or abnormal Doppler results. RESULTS: There were a total of 178 pregnancies in 51 patients. The overall percentage of abnormal ultrasounds was significantly greater in the untreated compared with treated pregnancies (52.8% vs. 27.9%; p = 0.024.) Growth restriction and abnormal Doppler results were more common in untreated pregnancies. There was a significantly decreased risk of oligohydramnios with treatment (27.3% vs. 7%; p = 0.03). Overall outcomes were significantly improved with the use of anticoagulation ( p < 0.0001). CONCLUSIONS: Treatment markedly improves ultrasound parameters of growth, fluid and feto-placental blood flow in patients with thrombophilia. The presence of abnormalities despite treatment reinforces the need for close antenatal surveillance.     

Masses of the tongue and floor of the mouth: findings on magnetic resonance imaging

The purpose of this study was to determine the value of MR imaging for the demonstration of masses in the tongue and floor of the mouth. Nine patients were prospectively examined with MR imaging after physical examination. Imaging protocol included T2 and contrast-enhanced and non-contrast-enhanced T1-weighted turbo spin-echo sequences, and the findings were compared with surgical and histopathological results. Histopathological examination revealed four squamous cell carcinomas, one adenoid cystic carcinoma, two tongue abscesses, and one chronic inflammatory change. The other case was diagnosed as hemangioma depending on clinical and imaging findings alone. In cases with squamous cell carcinoma, staging was done on the basis of MR imaging findings, and was found to be T4 in two cases, T3 in one case, and T2 in another. The primary role of MR imaging of the tongue and oropharynx is not to make a tissue diagnosis. Multiple deep biopsies are mandatory for the differentiation of other inflammatory and neoplastic lesions. Magnetic resonance imaging produces coronal and sagittal image planes to assess the volume and spread of the lesion and helps the surgeon determine the direction in which the biopsy should be performed. Received: 4 October 1999; Revised: 31 January 2000; Accepted: 6 April 2000     

Current status of micro/nanomotors in drug delivery

Abstract

Synthetic micro/nanomotors (MNMs) are novel, self-propelled nano or microscale devices that are widely used in drug transport, cell stimulation and isolation, bio-imaging, diagnostic and monitoring, sensing, photocatalysis and environmental remediation. Various preparation methods and propulsion mechanisms make MNMs “tailormade” nanosystems for the intended purpose or use. As the one of the newest members of nano carriers, MNMs open a new perspective especially for rapid drug transport and gene delivery. Although there exists limited number of in-vivo studies for drug delivery purposes, existence of in-vitro supportive data strongly encourages researchers to move on in this field and benefit from the manoeuvre capability of these novel systems. In this article, we reviewed the preparation and propulsion mechanisms of nanomotors in various fields with special attention to drug delivery systems.     

Examining changes in students' perception of science relevancy and their career aspirations: Integrating sustainability-oriented socio-scientific issues into general chemistry curriculum

Making science relevant to students' lives, future careers, or societies by introducing controversial socio-scientific issues in classrooms motivates students to take more active roles in learning science. This study explored the influence of integrating two sustainability-oriented socio-scientific issues (SOS₂Is) - alternative energies and nanotechnology-into the General Chemistry curriculum on 743 students' career aspirations and perceptions of science relevancy. For the presentation of topics, two learning environments on Prezi were prepared. The participants were guided to explore these learning environments that focused on pros and cons of each topic, including environmental and health hazards of technological developments. In addition, students were encouraged to link these discussions to sustainability issues in the context of the UN SDGs. The analysis of Changes in Attitude Towards the Relevancy of Science and Career Aspirations surveys indicated that the interventions improved students' perception of science relevancy and altered their career aspirations in many areas, regardless of their socioeconomic status and ethnic background. This study provides empirical evidence for the effectiveness of discussions around socio-scientific issues in changing students’ perceptions of science and career aspirations and recommends practical methods to encourage students to become global and scientifically literate citizens.