A Comprehensive Review on Current Treatments and Challenges Involved in the Treatment of Ovarian Cancer

Ovarian cancer (OC) is the second most common gynaecological malignancy. It typically affects females over the age of 50, and since 75% of cases are only discovered at stage III or IV, this is a sign of a poor diagnosis. Despite intraperitoneal chemotherapy's chemosensitivity, most patients relapse and face death. Early detection is difficult, but treatment is also difficult due to the route of administration, resistance to therapy with recurrence, and the need for precise cancer targeting to minimize cytotoxicity and adverse effects. On the other hand, undergoing debulking surgery becomes challenging, and therapy with many chemotherapeutic medications has manifested resistance, a condition known as multidrug resistance (MDR). Although there are other therapeutic options for ovarian cancer, this article solely focuses on co-delivery techniques, which work via diverse pathways to overcome cancer cell resistance. Different pathways contribute to MDR development in ovarian cancer; however, usually, pump and non-pump mechanisms are involved. Striking cancerous cells from several angles is important to defeat MDR. Nanocarriers are known to bypass the drug efflux pump found on cellular membranes to hit the pump mechanism. Nanocarriers aid in the treatment of ovarian cancer by enhancing the delivery of chemotherapeutic drugs to the tumour sites through passive or active targeting, thereby reducing unfavorable side effects on the healthy tissues. Additionally, the enhanced permeability and retention (EPR) mechanism boosts the bioavailability of the tumour site. To address the shortcomings of conventional delivery, the current review attempts to explain the current conventional treatment with special reference to passively and actively targeted drug delivery systems (DDSs) towards specific receptors developed to treat ovarian cancer. In conclusion, tailored nanocarriers would optimize medication delivery into the intracellular compartment before optimizing intra-tumour distribution. Other novel treatment possibilities for ovarian cancer include tumour vaccines, gene therapy, targeting epigenetic alteration, and biologically targeted compounds. These characteristics might enhance the therapeutic efficacy.

Vaccines: An Important Tool for Infectious Disease

Abstract:

Vaccines are usually regarded as one of the most important tools in the battle against infectious diseases. Even though currently accessible vaccinations are an incredible success story in contemporary medicine and have had a significant impact on global morbidity and death rates, it is evident that current vaccine delivery approaches need to be improved. To allow the successful creation of vaccinations against contagious diseases that have proven challenging to manage with conventional procedures, improvements are necessary. Improvements could include the introduction of innovative injectable adjuvants or novel delivery methods, such as mucosal immunization. Protection against infections that infect mucosal areas may necessitate mucosal delivery. Alternatively, innovative techniques for delivery, such as intradermal administration using self-administrable devices or the use of microneedle technology to bypass the stratum corneum's skin penetration barrier and aid in the transport of antigens, could be utilized to increase vaccine compliance. Needle-free delivery systems are of particular relevance for safer mass immunization programs, as they would prevent problems caused by needles reuse in several regions of the world, as well as needle-stick accidents. Based on this information, future vaccine development will mainly concentrate on rational antigen, adjuvant, and, most importantly, delivery mechanism design, resulting in new and improved vaccinations. In addition, this study discusses the current state and prospects of vaccine delivery via a variety of channels, including non- or minimally invasive approaches.

Biomarkers Apo10 and TKTL1: Epitope-detection in monocytes (EDIM) as a new diagnostic approach for cholangiocellular, pancreatic and colorectal carcinoma

OBJECTIVE

The EDIM (Epitope detection in monocytes) blood test is based on two biomarkers Apo10 and TKTL1. Apo10 is responsible for cell proliferation and resistance to apoptosis. TKTL1 plays a major role in anaerobic glycolysis of tumor cells, leading to destruction of the basal membrane and metastasis as well as in controlling cell cycle. For the first time we analyzed Apo10 and TKLT1 in patients with cholangiocellular (CCC), pancreatic (PC), and colorectal carcinoma (CRC).

METHODS

Blood samples of 62 patients with CCC, PC, and CRC were measured and compared to 29 control patients. We also investigated 13 patients with inflammatory conditions, because elevated TKTL1 and Apo10 have been previously described in affected individuals. Flow cytometry was used to detect surface antigens CD14+/CD16+ (activated monocytes/macrophages). Percentages of macrophages harboring TKTL1 and Apo10 were determined. A combined EDIM score (EDIM-CS: TKTL1 plus Apo10) was calculated. Results were correlated with serum tumor markers CEA and CA19-9.

RESULTS

Patients with CCC had 100% positive EDIM-CS but CEA and CA19-9 were positive in only 22.2% and 70%, respectively. Patients with PC had 100% positive EDIM-CS but positive tumor markers in only 37.5% (CEA) and 72.7% (CA19-9). Patients with CRC had 100% positive EDIM-CS but only 50% positive CEA. EDIM-CS was positive in 100% (62/62) of all cancer patients and in 0% of healthy individuals. Of the individuals with inflammation, 7.7% had a positive EDIM-CS.

CONCLUSION

The sensitivity of the EDIM blood test and the comparison with traditional tumor markers indicate that this new test might improve the detection of carcinomas (CCC, PC and, CRC) and might be relevant for the diagnosis of all tumor entities.

[Varicella gastritis under immunosuppression : Case report of a woman after lung transplantation due to granulomatosis with polyangiitis]

A 35-year-old woman who had previously undergone a lung transplantation presented with severe abdominal pain and vomiting. The gastroscopy showed diffuse ulcerative gastric lesions. Tests for varicella zoster virus and Epstein-Barr virus via polymerase chain reactions (PCR) on endoscopically obtained gastric biopsies were found to be positive and confirmed varicella gastritis. Intravenous antiviral therapy with acyclovir was administered resulting in a normalization of all clinical symptoms, especially of abdominal pain and inflammation parameters.

Meningitis and stridor in advanced Human immunodeficiency virus/acquired immune deficiency syndrome

A 37-year-old female presented confused with a preceding history of severe headache. After clinical examination and investigations, she was diagnosed with disseminated tuberculosis (including central nervous system involvement), and Human immunodeficiency virus/acquired immune deficiency syndrome. Her hospital stay was complicated. She developed stridor and a cerebrovascular accident with left hemiplegia. She died approximately 2 weeks after admission. The potential causes of her stridor included a mediastinal mass or a central mechanism secondary to tuberculosis meningitis. Limited resources precluded definitive imaging of the chest to rule out a mediastinal mass. Further, an autopsy was not done. Despite these limitations, this case is unique because it reports the presence of both stridor and tuberculosis meningitis in an adult patient.

Reperfusion damage: free radicals mediate delayed membrane changes rather than early ventricular arrhythmias

STUDY OBJECTIVE - The aim of the study was to reassess the role of reactive oxygen species in causing reperfusion arrhythmias, which they might do either by directly generating free oxygen radicals or by using scavengers of free oxygen radicals. DESIGN - Ventricular arrhythmias were studied in isolated rat hearts (n = 8-15 per experiment) subjected to regional ischaemia and treated with various free radical scavengers and spin trap agents. Reoxygenation automaticity was similarly studied in isolated guinea pig papillary muscles (n = 6-13 per experiment). MEASUREMENTS and RESULTS - In isolated rat hearts early reperfusion ventricular arrhythmias were unaltered by superoxide dismutase (1 X 10(5) IU.litre-1), catalase (1 X 10(6) IU.litre-1), N-tert-butyl-alpha-phenylnitrone (30 mumols.litre-1), 5,5-dimethyl-1-pyrroline-N-oxide (1 mmol.litre-1), or the combination of superoxide dismutase 1 X 10(5) IU.litre-1, catalase 1 X 10(6) IU.litre-1, and mannitol 10 mol.litre-1, or by the generation of the free radical .OH (Fe:ADP plus dihydroxyfumerate). In the isolated reoxygenated guinea pig papillary muscle, the incidence of reoxygenation automaticity was significantly reduced by verapamil 5 mumols.litre-1 but not by the following free oxygen radical scavengers: reduced glutathione (0.5 mmol.litre-1), N-acetyl cysteine (1 mmol.litre-1), the combination of superoxide dismutase (3 X 10(4) IU.litre-1) and catalase (5 X 10(3) IU.litre-1), or by pretreatment with allopurinol (30 mg.kg-1). Generating systems of .O2- or .OH induced relatively slow electrophysiological changes, including a decreased action potential duration. Reperfusion ventricular fibrillation in the rat heart was increased by increasing the extracellular calcium concentration from 1.25 to 1.9 or 2.5 mmol.litre-1, or by prolongation of the ischaemic time. CONCLUSIONS - Because of (a) the lack of an arrhythmogenic effect of free radical generating systems or of scavengers of free radicals, (b) the calcium sensitivity of reperfusion arrhythmias, and (c) the relatively slow time course of electrophysiological changes induced by free radical generating systems, we propose that free radicals are unlikely to be the prime cause of early ventricular arrhythmias in the systems that we tested. The mechanism of such arrhythmias is more likely to be a calcium sensitive process. The relatively slow electrophysiological changes mediated by free radicals suggest that these agents can cause delayed membrane change.

Inhibition by simulated ischemia or hypoxia of delayed afterdepolarizations provoked by cyclic AMP: significance for ischemic and reperfusion arrhythmias

Controversy exists about the role of an increased level of tissue cyclic adenosine 3'-5' monophosphate (cAMP) in the genesis of early ischemic ventricular arrhythmias. Evidence for an arrhythmogenic role for cAMP was proposed by Podzuweit et al. (1978) and Opie et al. (1979) who argued that ischemic ventricular fibrillation was associated with increased levels of tissue cAMP in the ischemic zone. Lubbe et al. (1978) found that infusion of dibutyryl (dBcAMP), or the beta-adrenergic stimulant epinephrine, or the phosphodiesterase inhibitor theophylline, all produced a marked fall in the ventricular fibrillation threshold and an increase in the duration of the vulnerable period of the isolated perfused rat heart. In contrast, Muller et al. (1986) recently showed that prevention of ventricular fibrillation by beta-adrenergic blockade is not directly associated with decreased levels of cAMP, while Manning et al. (1985) used forskolin to stimulate adenylate cyclase and found that the markedly elevated tissue cAMP levels in the rat heart did not promote ischemic or reperfusion arrhythmias. Some of these contradictions could be resolved if the electrophysiological mechanisms by which increased levels of cAMP might predispose to arrhythmias were better understood. It is known that intracellular injection of cAMP into cardiac myocytes can enhance delayed afterdepolarizations (DADs; Matsuda et al. 1982) and that DADs may explain certain arrhythmias such as those evoked by digitalis toxicity (Ferrier, 1977) or reperfusion (Ferrier et al. 1985).(ABSTRACT TRUNCATED AT 250 WORDS)

Proposed role of energy supply in the genesis of delayed afterdepolarizations--implications for ischemic or reperfusion arrhythmias

Delayed afterdepolarizations (DADs) are Ca++-dependent electrophysiological abnormalities, which are evoked by a variety of conditions that induce intracellular Ca++ overload, including fast pacing, isoproterenol, dibutyryl cyclic AMP, and intracellular injection of Ca++. Since Ca++ overload is suspected of playing a role in both ischemic and reperfusion cellular damage, a reasonable hypothesis would be that DADs could play a role in ischemic or reperfusion arrhythmias. No direct proof has, however, been obtained for such a role for DADs. We propose that DADs could be associated with arrhythmias in which there is Ca++ overload of sufficient magnitude to cause an increased oscillatory release of Ca++ from the sarcoplasmic reticulum (SR), provided energy is available in the form of ATP. A sustained increase of Ca++ is likely to reflect energy depletion and therefore exclude a significant contribution of DADs to arrhythmia development. Thus, DADs are more likely to play a role in: (i) reperfusion arrhythmias and (ii) arrhythmias arising in moderately ischemic tissue, than in severe ischemia with marked energy depletion.

Mechanism of reduction of action potential duration of ventricular myocardium by exogenous lactate

Shortening of the action potential duration and the attendant reduction of refractory period in regional myocardial ischaemia might set the stage for the genesis and re-entry of ectopic impulses. We investigated the mechanism by which neutral lactate shortens the action potential duration since lactate accumulates highest in regions where coronary flow is lowest after experimental coronary artery occlusion. In preliminary experiments (unpublished) when 10 mM of L(+)-Na lactate was substituted for glucose (10 mM), action potential duration shortened in the majority of guinea pig papillary muscles. In some of the muscles, the action potential duration lengthened. When the perfusate contained neither glucose nor lactate (i.e. substrate free) action potential duration shortened in the majority of experiments. As mechanism, we supposed that the relatively high contraction rate of the preparations (120/min) could exhaust glycogen stores thereby limiting glycolysis and shortening the action potential duration. Thus variable action potential duration during lactate or substrate-free superfusion, might be explained by a corresponding variability of pre-existing glycogen stores. Therefore, in the present study we attempted to reduce the demand on glycogen stores by decreasing the contraction rate to 30/min. In the latter preparation, when the diastolic (passive) tension was completely normal, lactate (10 mM) shortened the action potential duration by 30%, whereas the action potential duration was not altered during substrate free superfusion. We then explored the possibility that lactate shortened the action potential duration by inhibition of glycolysis. First, muscles were made to perform external work by increasing passive tension to the peak of the active length-tension curve.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of acute anthracycline cardiotoxicity in isolated rat hearts: carminomycin versus daunomycin

Cardiotoxicity limits the use of anthracyclines which are potent anticancer agents. In the isolated rat heart, we investigated the mechanism of acute anthracycline cardiotoxicity and compared a new anthracycline, carminomycin, with daunomycin which is in established use. Daunomycin 1.75 X 10(-5) M produced a fall in cardiac output (36 +/- 2 versus 58 +/- 1 ml/min; p less than 0.01), left ventricular power production (9 +/- 0.7 versus 16 +/- 0.3 mJ/sec/g; p less than 0.01), and efficiency of heart work (3.3 +/- 0.2 versus 6.3 +/- 0.2 mJ/sec/ml O2; p less than 0.01; mean +/- S.E. 40 min after daunomycin). Carminomycin (1.75 X 10(-5) M) produced a greater fall in cardiac output than equimolar daunomycin (26 +/- 2 versus 36 +/- 2 ml/min; p less than 0.01). Daunomycin did not reduce coronary flow rate, heart rate, or oxygen consumption. From the preceding data, we inferred that, since afterload and preload were constant in this model, heart failure was due to a depressed inotropic state. Procedures that increased cytosolic calcium relieved heart failure namely, pretreatment with digoxin (62.4 micrograms), isoproterenol (10(-6) M), and increased perfusate Ca2+ (5 mM versus 2.5 mM) all prevented carminomycin-induced fall in cardiac output (41 +/- 1, 47 +/- 5, and 52 +/- 1, respectively, versus 26 +/- 2 ml/min; p less than 0.01). Acute anthracycline contractile failure was also associated with a fall in high-energy phosphate compounds which could also have contributed to the decreased inotropic state. We conclude that carminomycin is more cardiotoxic than daunomycin in equimolar concentrations and that a lowered cytosolic calcium and decreased energy stores might cause the contractile failure. The cytosolic calcium and high-energy phosphate compounds were lowered by separate mechanisms.