Analysis of the lipid extraction performance in a cascade process for Scenedesmus almeriensis biorefinery.

BACKGROUND: Microalgae have attracted considerable interest due to their ability to produce a wide range of valuable compounds. Pulsed Electric Fields (PEF) has been demonstrated to effectively disrupt the microalgae cells and facilitate intracellular extraction. To increase the commercial viability of microalgae, the entire biomass should be exploited with different products extracted and valorized according to the biorefinery scheme. However, demonstrations of multiple component extraction in series are very limited in literature. This study aimed to develop an effective lipid extraction protocol from wet Scenedesmus almeriensis after PEF-treatment with 1.5 MJ·kgDW-1. A cascade process, i.e., the valorization of several products in row, was tested with firstly the collection of the released carbohydrates in the water fraction, then protein enzymatic hydrolysis and finally lipid extraction. Biomass processed with high pressure homogenization (HPH) on parallel, served as benchmark. RESULTS: Lipid extraction with ethanol:hexane (1:0.41 vol/vol) offered the highest yields from the different protocols tested. PEF-treatment promoted extraction with almost 70% of total lipids extracted against 43% from untreated biomass. An incubation step after PEF-treatment, further improved the yields, up to 83% of total lipids. Increasing the solvent volume by factor 2 offered no improvement. In comparison, extraction with two other systems utilizing only ethanol at room temperature or elevated at 60 °C were ineffective with less than 30% of total lipids extracted. Regarding cascade extraction, carbohydrate release after PEF was detected albeit in low concentrations. PEF-treated samples displayed slightly better kinetics during the enzymatic protein hydrolysis compared to untreated or HPH-treated biomass. The yields from a subsequent lipid extraction were not affected after PEF but were significantly increased for untreated samples (66% of total lipids), while HPH displayed the lowest yields (~ 49% of total lipids). CONCLUSIONS: PEF-treatment successfully promoted lipid extraction from S. almeriensis but only in combination with a polar:neutral co-solvent (ethanol:hexane). After enzymatic protein hydrolysis in cascade processing; however, untreated biomass displayed equal lipid yields due to the disruptive effect of the proteolytic enzymes. Therefore, the positive impact of PEF in this scheme is limited on the improved reaction kinetics exhibited during the enzymatic hydrolysis step.

Screening for intra-anal squamous intra-epithelial lesions in women with a history of human papillomavirus-related vulvar or perianal disease: results of a screening protocol.

AIM: Women with a history of human papillomavirus (HPV)-related cervical, vaginal or vulvar high-grade squamous intra-epithelial lesions (HSILs) or cancer are at increased risk of developing anal squamous intra-epithelial lesions (SILs) or a squamous cell carcinoma of the anus (SCCA). Screening for intra-anal SILs with high-resolution anoscopy (HRA) in high-risk populations is a subject of debate. In this study we aimed to answer the following question: what is the prevalence of intra-anal (H)SIL in women with HPV-related vulvar and/or perianal disease using HRA for screening? METHOD: A retrospective study was performed to evaluate the prevalence of intra-anal (H)SIL in women with a history of vulvar and/or perianal HSIL or (superficially invasive) squamous cell carcinoma (SCC). This study was performed between 2015 and 2018 following implementation of a protocol for intra-anal screening using HRA. RESULTS: Twenty-seven patients, 10 with a history of (superficially invasive) SCC (four vulvar, five perianal, one multizonal) and 17 with HSIL as the worst diagnosis (two perianal, 15 multizonal) were screened for intra-anal lesions using HRA. No anal cancer was found at screening, 6 (22%) patients were diagnosed with intra-anal HSIL and 12 (44%) patients with intra-anal low-grade SIL. CONCLUSIONS: We found a high prevalence of intra-anal HSIL in women previously diagnosed with vulvar and perianal HSIL. Given the clear link between HSIL and SCCA, screening for intra-anal lesions in women with HPV-related genital pathology seems warranted. Future studies should focus on the effect of HSIL treatment on the prevention of anal cancer.

Introduction of routine hepatitis B screening for all patients receiving cancer treatment.

BACKGROUND: Patients with a chronic hepatitis B virus (HBV) infection or patients who have recovered from an HBV infection are at risk for HBV reactivation (HBVr), especially if they need treatment with chemotherapy. International guidelines recommend routine HBV screening for all patients starting with chemotherapy. This study evaluates the implementation of a routine HBV screening protocol. METHODS: A retrospective study was performed between January 2015 and October 2016 at the Medical Centre Slotervaart Amsterdam. All patients with a solid or hematological malignancy starting intravenous chemotherapy were included. In September 2015, a protocol for routine HBV screening was introduced. HBV screening results were evaluated before and after implementation of the screening protocol. RESULTS: In total, 184 patients were included, of which 129 patients were actually screened; 37 of the 70 (53%) patients were screened in the group before implementation of the protocol and 92 of the 114 (81%) after implementation. Before routine HBV screening, 8/37 (21.6%) patients tested anti-HBc positive; after introduction of routine screening, 13/92 (14.1%) patients tested anti-HBc positive. After implementation of the screening protocol, no HBVr occurred. CONCLUSION: Implementation of routine HBV screening in patients starting chemotherapy increases identification of the number of patients identified as at risk for HBVr and contributes to prevention of HBVr. A high prevalence of anti-HBc positive patients was found during routine HBV screening, indicating the importance of screening. Awareness and implementation of routine HBV screening, together with knowledge of existing guidelines is necessary to increase the HBV screening rate in patients treated with chemotherapy.

Rare fatal vascular complication of transsphenoidal surgery.

We report the case of a 61-year-old man, who underwent transsphenoidal surgery for a pituitary macroadenoma. The presence of tough fibrous septa dividing the tumour permitted only a partial resection. Progressive loss of consciousness soon after surgery occurred, an emergency CT scan showed no evidence of haemorrhage. Twenty hours later, MRI revealed compression of both internal carotid arteries with arrest of arterial flow resulting in stroke by an enlarged haemorrhagic mass consistent with a pituitary apoplexy. On the second postoperative day, the patient died as a result of this extensive stroke. The mechanisms of this rare complication after transsphenoidal surgery are theorized and the sensitivity of imaging methods is discussed.

The role of gamma knife radiosurgery in children.

OBJECTS: Despite advances in microneurosurgery, the surgical management of deep-seated lesions is still associated with a high risk. Gamma knife radiosurgery (GKRS), however, has improved the outcome of cerebral tumors and arteriovenous malformations (AVMs) in delicate areas. METHODS: Between March 1992 and June 1998, 50 children (age 1-16 years) with intracranial lesions were treated with GKRS. There were 12 low-grade gliomas, 12 high-grade gliomas, 7 craniopharyngiomas, 3 hamartomas, 2 meningiomas of the skull base, 2 vestibular schwannomas, 1 pituitary adenoma, 1 choroid plexus papilloma, and 10 AVMs. The mean size of the pathologies was 4.6 cm3 (range: 0.21-25.5 cm3). A mean marginal dose of 16 Gy (8-25 Gy) was applied to a mean isodose surface of 50% (35-90%). Clinical and neuroradiological follow-up were analyzed for outcome. Follow-up periods of 45 of these patients ranged from 8 to 79 months (mean 36 months); 5 patients were lost to follow-up. Neoplasms decreased in size in 15 cases (41%), remained unchanged in 13 patients (35%), and increased in 9 cases (24%). AVMs obliterated in 3 children (38%) within 24 months. Neurological follow-up demonstrated improved clinical status in 7 patients (15.5%), stable neurological status in 31 cases (69%) and clinical deterioration in 7 patients (15.5%). The treatment was well tolerated and no complications occurred. CONCLUSIONS: GKRS represents a safe and effective treatment option for benign neoplasms or AVMs in pediatric patients and may extend survival times of children with malignant lesions.

Gamma knife treatment of subfoveal, classic neovascularization in age-related macular degeneration: a pilot study.

OBJECT: Age-related macular degeneration (AMD) is the leading cause of severe vision loss in people older than age 65 years in the western world. The visual acuity loss usually results from the ingrowth of new vessels from the choroid capillaries, so called choroidal neovascularization (CNV). The aim of this pilot study was to investigate the effect of a single-fraction gamma knife radiosurgery (GKS) on visual acuity and the growth pattern of CNV in patients with AMD. METHODS: Ten patients with a mean age of 75 years and with a subfoveal, classic CNV due to AMD were enrolled in this study. All patients were treated with GKS in one fraction with a prescription dose of 10 Gy. The treatment target was the CNV located in the macula. Computerized tomography scans of the globe were obtained. After a follow up of 1 year visual acuity was stable in six patients and decreased in four. The size of the CNV could be stabilized in four patients, and in six an enlargement of these neovascular complexes was shown. No side effects, such as cataract formation, development of radiation-induced retinopathy, or optic neuropathy, have been observed so far. CONCLUSIONS: Gamma knife radiosurgery seemed to have a beneficial effect on visual acuity in patients with AMD, but it failed to control growth of CNV in six patients. A longer follow up, a larger study population, and a randomized and controlled study are necessary for a final conclusion.

Common skin cancers in the United States: a practical guide for diagnosis and treatment.

Cutaneous malignancies are the most common cancers found in the primary care setting. It is imperative that all primary care providers become competent in evaluating skin lesions. Actinic keratoses are the most common premalignant lesions. These rough scaly plaques are the direct result of ultraviolet and other carcinogenic exposure. Actinic keratoses may be the first clinical sign to alert primary care practitioners of severe solar dermatitis and herald the development of skin cancer. Treatment is cryotherapy or topical chemotherapeutic agents such as 5-fluorouracil. Basal and squamous cell carcinomas are the most common nonmelanoma skin cancers. The primary cause is cumulative exposure to ultraviolet radiation from the sun, although other factors exist. Treatment is generally surgical excision performed by a practitioner skilled in this type of procedure contingent on tumor type, size, location, aggressiveness, and other factors. Other common treatments include electrodesiccation and curettage and cryotherapy. The incidence of malignant melanoma is the fastest rising cancer in the United States. Early detection and prevention are the mainstays of a good outcome. Depth of the lesion is the primary determinant in staging and prognosis, although other factors are also important. As the incidence of skin cancer increases, primary care practitioners play an integral role in the diagnosis, treatment, and prevention of skin cancer. The importance of early detection and appropriate referral by primary care providers will become even more crucial in the prognosis of afflicted patients.

Gamma knife radiosurgery for glomus jugulare tumours.

The aim of this clinical study was to determine the tumour control rate, clinical outcome and complication rate following gamma knife treatment for glomus jugulare tumours. Between May 1992 and May 1998, 13 patients with glomus tumours underwent stereotactic radiosurgical treatment in our department. The age of these patients ranged from 21 to 80 years. The male:female ratio was 2:11. Six patients had primary open surgery for partial removal or recurrent growth and subsequent radiosurgical therapy. Radiosurgery was performed as primary treatment in 7 cases. The median tumour volume was 6.4 cm3 (range: 4.6-13.7 cm3). The median marginal dose applied to an average isodose volume of 50% (30-50%) was 13.5 Gy (12-20 Gy). In 10 patients, a total of 48 MRI and CT follow-up scans were available. The remaining three patients have been excluded from the postradiosurgical evaluation since the observation time (t < 12 months) was too short or patients were lost to follow up. The median interval from Gamma Knife treatment to the last radiological follow-up was 37.6 months (5-68 months). In 4 patients (40%) decreased tumour volumes were observed and in 6 cases (60%) the tumour size remained unchanged. Neurological follow-up examinations revealed improved clinical status in 5 patients (50%), a stable neurological status in 5 patients (50%) and no complications occurred. According to our preliminary experience Gamma Knife radiosurgery represents an effective treatment option for glomus jugulare tumours.

Corpus callosotomy with radiosurgery.

OBJECTIVE: Corpus callosotomy is a surgical option for medically uncontrolled generalized epilepsy in appropriate patients. Because numerous complications related to open callosotomy are still reported, we performed radiosurgical corpus callosotomy with the gamma knife. METHODS: Between October 1992 and June 1995, three patients underwent stereotactic radiosurgery to ablate the anterior third of the corpus callosum. The patients had intractable epilepsy: two had Lennox-Gastaut syndrome, and one had multifocal epilepsy with atonic, tonicoclonic, and atypical absence seizures. The history of seizures ranged from 20 to 37 years' duration. Stereotactic radiosurgery was performed with a cobalt-60 gamma knife using a 4-mm collimator, targeted to the rostrum, genu, and anterior third of body of the corpus callosum. Two patients were treated once with 150 and 160 Gy at maximum, respectively, and one patient was treated in two stages with 50 Gy and then 170 Gy at maximum. RESULTS: The severity and frequency of seizures were significantly reduced in all three patients. The types of seizures associated with the most improved outcome were atonic and generalized tonicoclonic seizures. The mean follow-up period was 38 months. Hospitalization required for this procedure was 3 days. No complications related to irradiation were recorded except transient headache in one patient. CONCLUSION: The outcomes suggest that radiosurgical corpus callosotomy may be a promising alternative treatment to open callosotomy.

A veteran with acute mental changes years after combat.

A 49-year-old man presented with a five-week history of worsening confusion, agitation, and bizarre behavior. According to his mother and sister, who live with him, he had inexplicably jumped out of bed one day and complained of injuring his back. The pain apparently resolved within several days. Two weeks later, again just after awakening, he had experienced a period of confusion, lasting about 15 min. The latest episode occurred three days previously and included vivid hallucinations--at various times, he seemed to believe that he was talking to his brother on the telephone, drinking a glass of water, emptying the refrigerator, jumping into a foxhole, and stomping on rattlesnakes. He was disoriented to time as well as environment.

Chronic spinal subdural haematoma associated with intracranial subdural haematoma: CT and MRI.

Chronic spinal subdural haematoma is a uncommon. We describe the CT and MRI appearances of chronic spinal and intracranial subdural haematomas following minor trauma. The aetiology, pathogenesis and differential diagnosis are discussed.

Cerebral arteriovenous malformations: diagnostic value of echo-enhanced transcranial Doppler sonography compared with angiography.

BACKGROUND AND PURPOSE: The purpose of our study was to examine the clinical value of echo-enhanced transcranial power Doppler sonography (EE-TCD), including it ability to assess hemodynamic parameters of the intracranial vasculature, in patients with suspected cerebral arteriovenous malformations (AVMs) and to compare this method with angiography. METHODS: Sixteen patients with suspected cerebral AVMs were examined with EE-TCD and angiography. As an echo-enhancing agent, SHU 508A (Levovist) was administered intravenously by bolus injection in nine patients and by continuous infusion in seven. Sonograms were reviewed without knowledge of other imaging results and were correlated with angiographic findings. RESULTS: Angiography showed AVMs in 12 of 16 patients. Eleven lesions were located in the anterior or middle fossa and one was in the posterior fossa. EE-TCD was slightly less sensitive in the detection of AVMs (92%, 11/12 lesions), since in one patient the lacking acoustic window did not allow a transcranial examination. EE-TCD slightly underestimated AVM size compared with angiographic findings but showed feeding arteries with sufficient acoustic properties. In seven patients (58%), angiography revealed a coincidental blood supply from another intracranial or extracranial vessel, which was missed by EE-TCD in all cases. Assessment of peak systolic velocities and resistive indexes resulted in a higher (mean, 191.1 cm/s) and a lower (mean, 45.7%) value, respectively, in the feeding arteries as compared with the contralateral arteries (mean, 101.8 cm/s and 55.6%, respectively). Side-to-side differences were significantly higher in patients with AVMs than in those without a malformation. Signal enhancement was markedly longer with continuous infusion (mean, 520 seconds +/- 28.2) than with bolus injection (mean, 145 seconds +/- 10.5) of the contrast agent. CONCLUSION: In our limited study group, EE-TCD was a sensitive method for the detection of AVMs, and Levovist proved to be a safe and effective echo-enhancing substance.

Radiosurgery of glomus tumors: midterm results.

Glomus tumors (GT) of the skull-base present a complex surgical challenge due to their delicate localization and specific vascular supply. This study is designed to evaluate the role of stereotactic radiosurgery in the treatment of GT. Thirteen patients with GT have been treated with the Gamma Knife. Radiosurgery was performed because of recurrences after surgical removal in six patients. Histology was not available in seven patients, thus, diagnosis was made from neuroradiological features only. Two of them had partial embolization before Gamma Knife treatment. Clinical and morphological data were collected from 11 patients, who had a representative follow-up of at least 12 months. Mean follow-up was 42 months (range 14 to 72 months). Within the follow-up period there was no tumor progression and no clinical deterioration in any of the patients. 64% of the patients had an improvement of their symptoms, and in 36% the volume of the lesion decreased in size. There was no radiation-related morbidity. It is suggested that radiosurgery seems to be safe and effective in the treatment of GT.

Treatment of cerebral radionecrosis by hyperbaric oxygen therapy.

Clinically observed adverse radiation effects (ARE) are rather uncommon, but modern imaging reveals that they are more common after radiosurgery than previously believed. Little is known about the pathogenesis, and current treatment is mostly empirical. The benefit of hyperbaric oxygen therapy (HBO) on radiation-induced bone and soft tissue necrosis is known in lesions in the maxillofacial area, the mouth and in the head and neck. HBO raises the tissue pO2 and initiates a cellular and vascular repair mechanism. This forms the basis for the hypothesis that it might also help alleviate the results of cerebral radionecrosis. This study is a preliminary attempt to test this hypothesis. Two patients with arteriovenous malformations (AVMs) were chosen for the study. They had been treated with Gamma Knife radiosurgery (GKRS) and had developed imaging signs consistent with ARE. They were treated by breathing 100% oxygen at 2.5 atmospheres absolute (250 kPa) in sessions of 60 minutes per day. This treatment was repeated 40 times in cycles of ten sessions. Both responded well to HBO, one lesion disappeared and the other was reduced significantly in size. No adjuvant steroids were given. These results give evidence that HBO has a potential value in treating ARE but further experience will be needed to confirm its definite benefit.

Intracranial aneurysms: a review of endovascular and surgical treatment in 248 patients.

We reviewed the medium-term results of endovascular treatment of intracranial aneurysms and compared patient selection and results with those of open surgery. Between January 1992 and December 1995, a total of 248 consecutive patients were treated for 297 aneurysms (61 unruptured and 236 ruptured). 162 aneurysms in 142 patients (mean age, 48.5 years) were treated microsurgically and 134 aneurysms in 106 patients (mean age, 54.2 years) were treated by endovascular embolization with Guglielmi detachable coils (GDC). The mean follow-up was 2.6 years (range, 1.5 to 4.5 years). There was no significant difference in patient population and selection in terms of age, sex or location of aneurysms between both methods. Both modalities achieved excellent results (defined as no neurological deficit) in patients with unruptured aneurysms and with no or minor deficits after subarachnoid hemorrhage (SAH) between 71% and 88%. Patients with moderate deficits after SAH had excellent outcomes in 49% after open surgery, and 47% after embolization. Poor grade patients had, equally, as well an acceptable as a pour outcome, between 0% and 50%. There was no significant difference between the outcome of surgical or endovascular patients. We conclude that GDC embolization is not associated with a higher risk of morbidity and mortality than open surgery. This risk may even be lower for lesions in surgically unfavorable locations. The GDC technique is a less invasive, effective option to prevent re-bleeding in early stage, even in poor-grade patients. However, these encouraging medium-term results have to be confirmed by a longer observation period.

Dose-response tolerance of the visual pathways and cranial nerves of the cavernous sinus to stereotactic radiosurgery.

UNLABELLED: As the number of patients treated with stereotactic radiosurgery increases, it becomes particularly important to define with precision adverse effects on distinct structures of the nervous system. OBJECT: This study was designed to assess the dose-response tolerance of the visual pathways and cranial nerves after exposure of the cavernous sinus to radiation. METHODS: A total of 66 sites in the visual system and 210 cranial nerves of the middle cranial fossa were investigated in 50 patients who had undergone gamma knife treatment for benign skull base tumors. The mean follow-up period was 40 months (range 24-60 months). Follow-up examinations consisted of neurological, neuroradiological, and neuroophthalmological evaluations. The actuarial incidence of optic neuropathy was zero for patients who received a radiation dose of less than 10 Gy, 26.7% for patients receiving a dose in the range of 10 to less than 15 Gy, and 77.8% for those who received doses of 15 Gy or more (p < 0.0001). Previously impaired vision improved in 25.8% and was unchanged in 51.5% of patients. No sign of neuropathy was seen in patients whose cranial nerves of the cavernous sinus received radiation doses of between 5 and 30 Gy. Because tumor control appeared to have been achieved in 98% of the patients, the deterioration in visual function cannot be attributed to tumor progression. CONCLUSIONS: The structures of the visual pathways (the optic nerve, chiasm, and tract) exhibit a much higher sensitivity to single-fraction radiation than other cranial nerves, and their particular dose-response characteristics can be defined. In contrast, the oculomotor and trigeminal nerves have a much higher dose tolerance.