Publications by authors named "Clovis Orlando da Fonseca"

Perillyl alcohol (POH) is a monocyclic terpene that has strong antitumor activity. Brain tumors are particularly difficult to treat with therapeutic agents, and clinical trials have shown their low tolerance through oral administration. We proposed the entrapment of POH into an oil-in-water chitosan nanoemulsion aiming its intranasal administration for brain targeting.

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The inhalational administration of drugs is a practical and non-invasive approach with the potential to reduce side effects and with a quick onset of therapeutic activity. Perillyl alcohol (POH) is a monoterpene with antitumor activity that currently is undergoing clinical evaluation as an inhalational anticancer agent. A detection method was developed that will be applicable to pharmacokinetic studies of not only POH, but also its longer-lived main metabolite, perillic acid (PA), in lung tissue and plasma after inhalational delivery.

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It has been hypothesized that persistent ketotic hypoglycemia represents a potential therapeutic strategy against high-grade gliomas. Perillyl alcohol (POH) is a non-toxic, naturally-occurring, hydroxylated monoterpene that exhibits cytotoxicity against temozolomide-resistant glioma cells, regardless of O6-methylguanine-methyltransferase promoter methylation status. The present study aimed to evaluate the toxicity and therapeutic efficacy of intranasal POH when administered in combination with a ketogenic diet (KD) program for the treatment of patients with recurrent glioblastoma.

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Background: Awake craniotomy with brain mapping is the gold standard for eloquent tissue localization. Patients' tolerability and satisfaction have been shown to be high; however, it is a matter of debate whether these findings could be generalized, since patients across the globe have their own cultural backgrounds and may perceive and accept this procedure differently.

Methods: We conducted a prospective qualitative study about the perception and tolerability of awake craniotomy in a population of consecutive brain tumor patients in Brazil between January 2013 and April 2015.

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Background: Hemipelvectomy is a major orthopedic surgical procedure indicated in specific situations. Although many studies discuss surgical techniques for hemipelvectomy, few studies have presented survival data, especially in underdeveloped countries. Additionally, there is limited information on anesthesia for orthopedic oncologic surgeries.

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Tumors consist of cells in different stages of transformation with molecular and cellular heterogeneity. By far, heterogeneity is the hallmark of glioblastoma multiforme (GBM), the most malignant and aggressive type of glioma. Most proteomic studies aim in comparing tumors from different patients, but here we dive into exploring the intratumoral proteome diversity of a single GBM.

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Background: Gliomas display a high degree of intratumor heterogeneity, including changes in physiological parameters and lipid composition of the plasma membrane, which may contribute to the development of drug resistance. Biophysical interactions between therapeutic agents and the lipid components at the outer plasma membrane interface are critical for effective drug uptake. Amphipathic molecules such as perillyl alcohol (POH) have a high partition coefficient and generally lead to altered lipid acyl tail dynamics near the lipid-water interface, impacting the lipid bilayer structure and transport dynamics.

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Perillyl alcohol (POH) presents antitumoral activity but clinical application is hampered by adverse effects following oral administration. This work aimed to verify the cytotoxic effect of intranasal POH administration in the histology of lung, liver, brain; the cellularity and function of peripheral and bronchoalveolar-associated immune system. C57 adult mice received 1-min inhalation with POH, vehicle 70 % ethanol or saline buffer, once (84 μg/day) or twice (164 μg/day) during five consecutive days, and were killed 72 h after treatment.

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Article Synopsis
  • The study investigates the link between the EGF+61A>G genetic polymorphism and the risk of developing malignant gliomas, looking at its effects on EGF levels and response to treatment with intranasal perillyl alcohol.
  • Participants included 83 patients with recurrent glioma and 196 cancer-free controls, using techniques like PCR to analyze genetic differences and enzyme immunoassays to measure EGF levels.
  • Results indicate that specific genotypes (AA) are more common in glioblastoma patients and correlate with higher EGF levels, while lower EGF levels are associated with better survival and response to treatment.
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Glioblastoma multiform (GBM) is by far the most malignant glioma. We have introduced a new treatment for GBMs that comprises the inhalation of a naturally occurring terpene with chemotherapeutic properties known as perillyl alcohol (POH). Clinical trial results on recurrent GBM patients showed that POH extends the average life by more than eight months, temporarily slows tumor growth, and in some cases even decreases tumor size.

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Perillyl alcohol (POH) is a naturally occurring monoterpene with antiangiogenic and anti-tumoral properties. This chemotherapeutic agent has proven effectiveness in several clinical trials, including an ongoing phase I, comprising patients with recurrent glioblastoma multiform (GBM) under treatment with POH by intranasal administration. Proteomics offers tools to distinguish states of biological systems according to protein expression differences and therefore, can be used to gain pathological insights and to search for disease follow-up biomarkers.

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Introduction: Targeted therapy directed at specific molecular alterations is already creating a shift in the treatment of cancer patients. Malignant gliomas commonly overexpress the oncogenes EGFR and PDGFR and contain mutations and deletions of the tumor suppressor genes PTEN and TP53. Some of these alterations lead to activation of the P13K/Akt and Ras/MAPK pathways, which provide targets for therapy.

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Background: Activation of the p21-ras signaling pathway from aberrantly expressed receptors promotes the growth of malignant human astrocytomas. Perillyl alcohol has shown to have both chemopreventive and chemotherapeutic activities in preclinical studies. The underlying action mechanism(s) of POH has yet to be delineated but may involve effects on the TGF-beta and/or the Ras signaling pathways.

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Tumors of glial origin such as glioblastoma multiforme (GBM) comprise the majority of human brain tumors. Despite advances in surgery, radiation, and chemotherapy, the prognosis for patients with malignant glioma has not improved, emphasizing the need for a search for new chemotherapeutic drugs. Deregulated p21-Ras function, as a result of mutation, overexpression, or growth factor-induced overactivation, contributes to the growth of GBM.

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Standard treatment of glioblastoma multiforme consisting of surgical resection, radiation and/or chemotherapy is rarely curative, emphasizing the need for new chemotherapeutic drugs. The monoterpene perillyl alcohol (POH) has preventive and therapeutic effects in a wide variety of pre-clinical tumor models and is currently under phase I and II clinical trials. In the present study, we analyzed its effect on human glioblastoma cell lines (U87 and A172) and a primary cell culture derived from a human glioblastoma tumor specimen (GBM-1).

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The search for new chemotherapeutic drugs has increased, especially for those that have a natural origin. The monoterpene perillyl alcohol (POH) has been shown to exert chemopreventive activity in mammary, liver, and lung tumor models. It has also been used to treat a variety of rodent cancers, including pancreatic and breast carcinomas.

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