Leiomyoma and the importance of genetic variation on genes related to the vasculature system - CβS, MTHFR, NOS3, CYBA, and ACE1

OBJECTIVE

The link between the systemic vasculature system and tumor biology is here investigated by studying the contribution of CβS (844ins68), MTHFR (677C > T), NOS3 (4a/4b), CYBA (C242T), and ACE1 (I/D) genes to leiomyoma onset, uterus and leiomyoma volumes.

METHODS

DNA samples from 130 women with leiomyomas and 527 from healthy women were genotyped by PCR or PCR-RFLP. Qui-square (χ2) or Fisher's exact test were used to test associations. All the mentioned tests were performed in IBM® SPSS® Statistics Version 28. Statistical significance was defined as a p-value < 0.05.

RESULTS

Results revealed that CβS (in the codominant and allelic models, p = 0.044 and, p = 0.015, OR = 1.791 [1.114-2.879], respectively), MTHFR (in the codominant, allelic and dominant models, p = 0.009, p = 0.002, OR = 0.585 [0.416-0.824] and p = 0.003, OR = 0.527 [0.346-0.802], respectively) and ACE1 (dominant model, p = 0.045, OR = 0.639 [0.411-0.992]) genes are associated with leiomyoma onset. NOS3 4a4a genotype is associated with a lower uterus volume (p = 0.004). This study also uncovers intriguing epistatic interactions among some genes that further accentuate their roles in disease modulation. Indeed, the epistatic interactions between the CC genotype (MTHFR) and (+/+) (CβS; p = 0.003), 4b4b (NOS3; p = 0.006, OR = 2.050 [1.223-3.439]) or DD (ACE1; p < 0.001, OR = 2.362 [1.438-3.880]) were shown to be associated with the disease, while 4a presence (NOS3) in epistasis with I presence (ACE1), increased the effect protection having just the I allele presence (p = 0.029, OR = 0.446 [0.214-0.930]).

CONCLUSIONS

We conclude that variation in genes related to the systemic vascular system can play a role in the onset and development of leiomyoma.

Genetic Modulation of HPV Infection and Cervical Lesions: Role of Oxidative Stress-Related Genes

Human papillomavirus (HPV) infection is a necessary but not sufficient factor for the development of invasive cervical cancer (ICC) and high-grade intraepithelial lesion (HSIL). Oxidative stress is known to play a crucial role in HPV infection and carcinogenesis. In this study, we comprehensively investigate the modulation of HPV infection, HSIL and ICC, and ICC through an exploration of oxidative stress-related genes: CβS, MTHFR, NOS3, ACE1, CYBA, HAP, ACP1, GSTT1, GSTM1, and CYP1A1. Notably, the ACE1 gene emerges as a prominent factor with the presence of the I allele offering protection against HPV infection. The association of NOS3 with HPV infection is perceived with the 4a allele showing a protective effect. The presence of the GSTT1 null mutant correlates with increased susceptibility to HPV infection, HSIL and ICC, and ICC. This study also uncovers intriguing epistatic interactions among some of the genes that further accentuate their roles in disease modulation. Indeed, the epistatic interactions between the BB genotype (ACP1) and DD genotype (ECA1) were shown to increase the risk of HPV infection, and the interaction between BB (ACP1) and 0.0 (GSTT1) was associated with HPV infection and cervical lesions. These findings underscore the pivotal role of four oxidative stress-related genes in HPV-associated cervical lesions and cancer development, enriching our clinical understanding of the genetic influences on disease manifestation. The awareness of these genetic variations holds potential clinical implications.

Unveiling the membrane bound dihydroorotate: Quinone oxidoreductase from Staphylococcus aureus

Staphylococcus aureus is an opportunistic pathogen and one of the most frequent causes for community acquired and nosocomial bacterial infections. Even so, its energy metabolism is still under explored and its respiratory enzymes have been vastly overlooked. In this work, we unveil the dihydroorotate:quinone oxidoreductase (DHOQO) from S. aureus, the first example of a DHOQO from a Gram-positive organism. This protein was shown to be a FMN containing menaquinone reducing enzyme, presenting a Michaelis-Menten behaviour towards the two substrates, which was inhibited by Brequinar, Leflunomide, Lapachol, HQNO, Atovaquone and TFFA with different degrees of effectiveness. Deletion of the DHOQO coding gene (Δdhoqo) led to lower bacterial growth rates, and effected in cell morphology and metabolism, most importantly in the pyrimidine biosynthesis, here systematized for S. aureus MW2 for the first time. This work unveils the existence of a functional DHOQO in the respiratory chain of the pathogenic bacterium S. aureus, enlarging the understanding of its energy metabolism.

Leg stiffness and muscle power vs manometer in sportswomen with symptoms of stress urinary incontinence

BACKGROUND

Pelvic floor muscle training can cure or alleviate stress urinary incontinence. This study aimed to evaluate maximum voluntary contractions of the pelvic floor muscle in sportswomen and verify the association with leg stiffness and muscle power, both maximal and submaximal.

METHODS

The sample consisted of 41 sportswomen between 18 and 42 years of age. Pelvic floor muscle strength was measured by the manometer. The sportswomen were instructed to perform 3 maximum voluntary contractions of the perineum, held for 3 seconds. Maximal and submaximal leg stiffness and muscle power were measured with a force platform, in two conditions: 1st condition was the sub-maximal, double leg hop test, which was performed allowing sportswomen to self-select their preferred frequency and 2nd condition was the maximal double leg hop test, which was performed asking athletes to maximize hop height and minimize contact time on the top of the force platform for 6 consecutive hops.

FINDINGS

Maximal and submaximal leg stiffness values increase with increasing age, weight, height, and body mass index, showing positive and significant (p <0.05) or close correlations. There are strong positive correlations between maximal and submaximal leg stiffness (r = 0.759) and between maximal and submaximal muscle power. Maximum voluntary contractions values decrease with increasing leg stiffness: the correlation is significant with maximal leg stiffness.

INTERPRETATION

Maximum voluntary contractions values decrease with increasing leg stiffness and increase with increasing muscle power values. If the training program aims to increase muscle power, it may also increase maximum voluntary contractions.

Assessment of pelvic floor muscles in sportswomen: Quality of life and related factors

OBJECTIVES

To evaluate Maximum Voluntary Contraction (MVC) of the Pelvic Floor Muscles (PFM) in sportswomen, to observe the urinary symptoms and their impact on the Quality of Life (QoL).

DESIGN

Observational cross-sectional study.

SETTING

Gyms and teams in the North of Portugal.

PARTICIPANTS

Sportswomen (n = 197).

MAIN OUTCOME MEASURES

The measurement was performed using a manometer. The sportswomen were instructed to perform 3 MVC of the perineum, held for 3 s. The Kings Health Questionnaire (KHQ) was used to evaluate urinary symptoms and the QoL of the sportswomen.

RESULTS

Age significantly influenced (p < 0.05) the QoL in all domains. An increase in BMI was also significantly associated with a decrease in the QoL. MVC values had a highly significant effect on the overall QoL and all domains, including a reduction in urinary symptoms. The weekly time of physical activity was associated with a better QoL in symptomatology. The practice of high-impact activities decreased the QoL (compared to low-impact activities). The vaginal resting pressure values ranged from 1.60 to 59.80 (24.34 ± 11.00).

CONCLUSIONS

Age, BMI and high-impact sports appear to be the leading factors that promote the onset of SUI, which in turn decrease the QoL in sportswomen. There was a positive association between MVC and weekly time of physical activity in the QoL.

Lesão por pressão: incidência em unidades críticas de um hospital regional

Objetivo: Mensurar a incidência de lesão por pressão (LP) em usuários internados em unidades críticas de uma instituição pública de referência no sudoeste da Bahia. Método: Estudo longitudinal prospectivo. Os dados foram coletados entre junho e agosto de 2017, por meio de entrevista direta, prontuário, prescrição médica e inspeção da pele do participante. Resultados: Dos 83 participantes, 39 (47%) desenvolveram LP. A média de permanência no estudo foi de 6,8 dias. A maioria era do sexo masculino, de cor preta ou parda e tinha baixa escolaridade. A média de idade foi de 47,6 anos (±19,8). Foi evidenciado que o uso contínuo de drogas vasoativas e sedoanalgesia está associado à LP. Trinta e dois (38,55%) participantes apresentaram alto risco para desenvolvimento de LP. A região calcânea (44%) foi a mais acometida. O número de lesões por participante foi de 1,28, em média, predominando lesões no estágio 1 (68%). A ocorrência de desfecho desfavorável (óbito) foi estatisticamente significativa. Conclusão: O caráter multifatorial de surgimento das LP requer a adoção de medidas institucionais focadas na prevenção deste evento adverso, devendo fazer parte do processo de educação permanente dos profissionais.

Pressure injury: incidence in critical units of a regional hospital

Objectives: Measuring the incidence of pressure injury (PI) in users hospitalized in critical units of a public reference institution in southwestern Bahia. Method: Prospective longitudinal study. Data were collected between June and August of 2017, through a direct interview, medical records, medical prescription and inspection of the participant’s skin. Results: Of the 83 participants, 39 (47%) developed PI. The medium stay in the study was 6.8 days. Most of them were male, black or brown and had low schooling. The mean age was 47.6 years (± 19.8). It was evidenced that the continuous use of vasoactive drugs and sedoanalgesia is associated with PI. Thirty- two (38.55%) participants presented a high risk for PI development. The calcaneal region (44%) was the most affected. The number of lesions per participant was 1.28, on average, with lesions in stage 1 (68%) predominating. The occurrence of an unfavorable outcome (death) was statistically significant. Conclusion: The multifactorial character of the emergence of PI requires the adoption of institutional measures focused on the prevention of this adverse event, and should be part of the process of permanent education of professionals.

Influencia del sistema de producción en la calidad de la canal de cerdos de raza Bísara

La utilización de razas locales en sistemas de producción alternativos presenta una serie de ventajas, como la gestión medioambiental, la biodiversidad y la producción agrícola sostenible orientada hacia un mercado de productos de calidad diferenciada, especialmente en áreas desfavorecidas. En este trabajo se estudió la influencia de dos sistemas de producción en la calidad de la canal de cerdos de raza Bísara. La alimentación recibida fue igual en ambos casos. En la fase de crecimiento (98 días) se alimentaron con pienso compuesto comercial, mientras que durante el acabado se les administró pienso compuesto y harina de maíz. Se recogieron datos de peso vivo y canal después de 24h a 4ºC y se calculó el rendimiento de la canal. Se realizaron medidas morfométricas lineales de la media canal derecha, tras 24h post-mortem. El espesor de la grasa dorsal se midió a nivel de la 1ª costilla, la última costilla, en el músculo gluteus medius en el área más espesa de grasa (extremo craneal) y en la de inferior espesura. Teniendo en cuenta los resultados obtenidos, no se observan diferencias significativas en ninguno de los parámetros analizados. El peso de la canal fría (94,23±7,55 kg) y el rendimiento (75,51±1,48%) así como las medidas morfométricas mostraron valores prácticamente coincidentes entre ambos tipos de sistemas de producción. Tampoco se observaron diferencias en el espesor de la grasa dorsal. Las cuatro medidas indican un grado elevado y homogéneo de grasa dorsal, característica frecuentemente constatada en razas de cerdos no mejoradas (razas locales) existentes en todo el mundo.

Crecimiento de cerdos Bísaros alojados en un sistema hoop barn y en confinamiento tradicional

El objetivo de este estudio fue evaluar el crecimiento de cerdos alojados en un sistema hoop barn, en comparación con el confinamiento tradicional. Veinte cerdos de raza Bísaro, con 98,6±5,71 días de edad y 25,4±4,87 kg de peso vivo, se distribuyeron aleatoriamente en dos grupos: GR1 - hoop barn (2,4 m2/cerdo) con acceso al exterior (200 m2/cerdo); GR2 - confinamiento tradicional con cama de paja (1,8 m2/cerdo). La dieta fue igual para ambos grupos. Durante la fase de crecimiento (98 días) y hasta 80 kg de peso vivo, los animales fueron sometidos a una dieta con concentrado. A continuación, durante 70 días y hasta el sacrificio (110-120 kg de peso vivo), también estaba disponible harina de maiz. La ingesta de alimento por grupo se registró diariamente y los pesos vivos individuales se recogieron por quincena. La ganancia media diaria (ADG) durante la fase de crecimiento fue de 0,546±0,10 kg (Gr1) y 0,563±0,05 kg (Gr2) sin diferencias significativas (P> 0,05), pero con mayor variabilidad en el sistema hoop barn (CV de 18,1% vs. 8,8% de confinamiento). En la fase de acabado, el ADG fue 0,535±0,09 kg (Gr1) y 0,505±0,07 kg (Gr2) (P> 0,05). La eficiencia de conversación alimenticia (FCR) en las fases de crecimiento y de acabado fue de 3,11 kg/kg (Gr1) y 3,12 kg/kg (Gr2) y 3,44 (Gr1) y 3,53 (Gr2), respectivamente. A pesar de las diferencias en el alojamiento, la ADG y el FCR fueron idénticos en ambos sistemas de producción. Para el consumidor, las ganancias asociadas con el sistema hoop barn, como el uso de tierras no cultivadas, el bienestar del cerdo y la imagen del producto, son atractivas y por lo tanto, esto se reflejará en el mercado.

Pseudohypoparathyroidism type I-b with neurological involvement is associated with a homozygous PTH1R mutation

Pseudohypoparathyroidism type 1b (PHP1b) is characterized by hypocalcemia, hyperphosphatemia, increased levels of circulating parathyroid hormone (PTH), and no skeletal or developmental abnormalities. The goal of this study was to perform a full characterization of a familial case of PHP1b with neurological involvement and to identify the genetic cause of disease. The initial laboratory profile of the proband showed severe hypocalcemia, hyperphosphatemia and normal levels of PTH, which was considered to be compatible with primary hypoparathyroidism. With disease progression the patient developed cognitive disturbance, PTH levels were found to be slightly elevated and a picture of PTH resistance syndrome seemed more probable. The diagnosis of PHP1b was established after the study of family members and blunted urinary cAMP results were obtained in a PTH stimulation test. Integration of whole genome genotyping and exome sequencing data supported this diagnosis by revealing a novel homozygous missense mutation in PTH1R (p.Arg186His) completely segregating with the disease. Here, we demonstrate segregation of a novel mutation in PTH1R with a phenotype of PHP1b presenting with neurological symptoms, but no bone defects. This case represents the extreme end of the spectrum of cognitive impairment in PTH dysfunction and defines a possible novel form of PHP1b resulting from the impaired interaction between PTH and PTH1R.

Minhota breed cattle: carcass characterisation and meat quality affected by sex and slaughter age

This work focuses on the effect of slaughter age (6 and 9 months) and sex on carcass characteristics and meat quality of the Minhota cattle breed. In this study, data from 52 cattle (34 entire males and 18 females) were used for the carcass and meat characterisation. Regarding carcass characteristics, entire male carcasses (158 kg and 223 kg for animals of 6 and 9 months, respectively), were heavier than female carcasses (130 kg and 161 kg for animals of 6 and 9 months, respectively), with better dressing percentages, increased lengths, thicknesses and depths and compactness indexes. The quality of meat from carcasses of both entire males and females had strong luminosity (L*), a pale pink tone (lower a*-value) and high yellowness. Mean tenderness of Longissimus thoracis, expressed as shear force, was below 5.5 kg/cm2, without significant differences (P > 0.05) between either the slaughter age or sex.

White matter alterations in the brains of patients with active, remitted, and cured cushing syndrome: a DTI study

BACKGROUND AND PURPOSE

Cushing syndrome appears after chronic exposure to elevated glucocorticoid levels. Cortisol excess may alter white matter microstructure. Our purpose was to study WM changes in patients with Cushing syndrome compared with controls by using DTI and the influence of hypercortisolism.

MATERIALS AND METHODS

Thirty-five patients with Cushing syndrome and 35 healthy controls, matched for age, education, and sex, were analyzed through DTI (tract-based spatial statistics) for fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity (general linear model, family-wise error, and threshold-free cluster enhancement corrections, P < .05). Furthermore, the influence of hypercortisolism on WM DTI changes was studied by comparing 4 subgroups: 8 patients with Cushing syndrome with active hypercortisolism, 7 with Cushing syndrome with medication-remitted cortisol, 20 surgically cured, and 35 controls. Cardiovascular risk factors were used as covariates. In addition, correlations were analyzed among DTI values, concomitant 24-hour urinary free cortisol levels, and disease duration.

RESULTS

There were widespread alterations (reduced fractional anisotropy, and increased mean diffusivity, axial diffusivity, and radial diffusivity values; P < .05) in patients with Cushing syndrome compared with controls, independent of the cardiovascular risk factors present. Both active and cured Cushing syndrome subgroups showed similar changes compared with controls. Patients with medically remitted Cushing syndrome also had reduced fractional anisotropy and increased mean diffusivity and radial diffusivity values, compared with controls. No correlations were found between DTI maps and 24-hour urinary free cortisol levels or with disease duration.

CONCLUSIONS

Diffuse WM alterations in patients with Cushing syndrome suggest underlying loss of WM integrity and demyelination. Once present, they seem to be independent of concomitant hypercortisolism, persisting after remission/cure.

Microstructural white-matter abnormalities associated with treatment resistance, severity and duration of illness in major depression

BACKGROUND

Although white-matter abnormalities have been reported in middle-aged patients with major depressive disorder (MDD), few data are available on treatment-resistant MDD and the influence of relevant variables related to clinical burden of illness is far from being well established.

METHOD

The present study examined white-matter microstructure in a sample of 52 patients with MDD in different stages (treatment-resistant/chronic MDD, n = 18; remitted-recurrent MDD, n = 15; first-episode MDD, n = 19) and 17 healthy controls, using diffusion tensor imaging with a tract-based spatial statistics approach. Groups were comparable in age and gender distribution, and results were corrected for familywise error (FWE) rate.

RESULTS

Widespread significant reductions of fractional anisotropy (FA) - including the cingulum, corpus callosum, superior and inferior longitudinal fascicule - were evident in treatment-resistant/chronic MDD compared with first-episode MDD and controls (p < 0.05, FWE-corrected). Decreased FA was observed within the ventromedial prefrontal region in treatment-resistant/chronic MDD even when compared with the remitted-recurrent MDD group (p < 0.05, FWE-corrected). Longer duration of illness (β = -0.49, p = 0.04) and higher depression severity (at a trend level: β = -0.26, p = 0.06) predicted lower FA in linear multiple regression analysis at the whole-brain level. The number of previous episodes and severity of symptoms were significant predictors when focused on the ventromedial prefrontal area (β = -0.28, p = 0.04; and β = -0.29, p = 0.03, respectively). Medication effects were controlled for in the analyses and results remained unaltered.

CONCLUSIONS

Our findings support the notion that disruptions of white-matter microstructure, particularly in fronto-limbic networks, are associated with resistance to treatment and higher current and past burden of depression.

Monoterpenic aldehydes as potential anti-Leishmania agents: activity of Cymbopogon citratus and citral on L. infantum, L. tropica and L. major

In order to contribute for the search of new drugs for leishmaniasis, we study the susceptibility of Leishmania infantum, Leishmania tropica and Leishmania major to Cymbopogon citratus essential oil and major compounds, mrycene and citral. C. citratus and citral were the most active inhibiting L. infantum, L. tropica and L. major growth at IC(50) concentrations ranging from 25 to 52 μg/ml and from 34 to 42 μg/ml, respectively. L. infantum promastigotes exposed to essential oil and citral underwent considerable ultrastructural alterations, namely mitochondrial and kinetoplast swelling, autophagosomal structures, disruption of nuclear membrane and nuclear chromatin condensation. C. citratus essential oil and citral promoted the leishmanicidal effect by triggering a programmed cell death. In fact, the leishmanicidal activity was mediated via apoptosis as evidenced by externalization of phosphatidylserine, loss of mitochondrial membrane potential, and cell-cycle arrest at the G(0)/G(1) phase. Taken together, ours findings lead us to propose that citral was responsible for anti-Leishmania activity of the C. citratus and both may represent a valuable source for therapeutic control of leishmaniasis.

Acute effects of a single dose of phosphodiesterase type 5 inhibitor (sildenafil) on systemic arterial blood pressure during exercise and 24-hour ambulatory blood pressure monitoring in heart transplant recipients

BACKGROUND

Arterial systemic hypertension (SH) can be associated with a decrease in endothelium-dependent nitric oxide (NO). Sildenafil increases cyclic guanosine monophosphate (cGMP), a mediator of NO. However, little is known about the effects of PDE5 inhibition on 24-hour ambulatory pressure (ABP) and exercise blood pressure, noreprinephrine (Nor), and exercise capacity, especially after orthotopic heart transplantation (OHT).

METHODS

We studied 22 OHT patients who on the 1st day underwent a cardiopulmonary (CP) self-controlled treadmill 6' walk test (6') and, then, an ECG monitored CP treadmill maximal exercise test (Ex) within 60 and 90 minutes after oral Sildenafil (Sil; 50 mg) or placebo (Pl) given at random, and ABP. We determined at basal position (b), in the last minute of the 6' and at the peak Ex, the HR (bpm), Systolic blood pressure (SBP), and diastolic blood pressure (DBP), (mm Hg), VO2 (mL/kg/min), Slope VE/VCO2, exercise time (ET, min), distance (D; miles), and Nor (pg/mL). Also, after CP tests, 24-h SBP and DBP, the measurements were repeated on the 2nd day when the cross-over was done.

RESULTS

Sil significantly reduced blood pressure in the basal position and during exercise. It also promoted a significant reduction in SBP and DBP during 24 hours, daytime and nighttime. Sil did not change exercise capacity.

CONCLUSION

The NO-cGMP pathway seems to play a role in blood pressure control in OHT. In addition to antihypertensive therapy, PDE5 inhibition may have potential beneficial effects on hypertensive OHT.

Cationic lipid-DNA complexes in gene delivery: from biophysics to biological applications

Great expectations from the application of gene therapy approaches to human disease have been impaired by the unsatisfactory clinical progress observed. Among others, the use of an efficient carrier for nucleic acid-based medicines is considered to be a determinant factor for the successful application of this promising therapeutic strategy. The drawbacks associated with the use of viral vectors, namely those related with safety problems, have prompted investigators to develop alternative methods for gene delivery, cationic lipid-based systems being the most representative. This review focuses on the various parameters that are considered to be crucial to optimize the use of cationic lipid-DNA complexes for gene therapy purposes. Particular emphasis is devoted to the analysis of the different stages involved in the transfection process, from the biophysical aspects underlying the formation of the complexes to the different biological barriers that need to be surpassed for gene expression to occur.

Human serum albumin enhances DNA transfection by lipoplexes and confers resistance to inhibition by serum

Cationic liposome-DNA complexes ('lipoplexes') are used as gene delivery vehicles and may overcome some of the limitations of viral vectors for gene therapy applications. The interaction of highly positively charged lipoplexes with biological macromolecules in blood and tissues is one of the drawbacks of this system. We examined whether coating cationic liposomes with human serum albumin (HSA) could generate complexes that maintained transfection activity. The association of HSA with liposomes composed of 1, 2-dioleoyl-3-(trimethylammonium) propane and dioleoylphosphatidylethanolamine, and subsequent complexation with the plasmid pCMVluc greatly increased luciferase expression in epithelial and lymphocytic cell lines above that obtained with plain lipoplexes. The percentage of cells transfected also increased by an order of magnitude. The zeta potential of the ternary complexes was lower than that of the lipoplexes. Transfection activity by HSA-lipoplexes was not inhibited by up to 30% serum. The combined use of HSA and a pH-sensitive peptide resulted in significant gene expression in human primary macrophages. HSA-lipoplexes mediated significantly higher gene expression than plain lipoplexes or naked DNA in the lungs and spleen of mice. Our results indicate that negatively charged HSA-lipoplexes can facilitate efficient transfection of cultured cells, and that they may overcome some of the problems associated with the use of highly positively charged complexes for gene delivery in vivo.

Color dynamics of diffraction gratings: evaluation and applications in optical security

We looked for design methodologies that cope with optical specifications described in terms of trajectories in the CIE (Commission Internationale de l'Eclairage) 1976 chromaticity diagram in the context of low-cost mass-reproduction processes that inevitably introduce changes in the design of a diffractive device for security applications. The mathematics of the design process can be strongly simplified if the theory of planar waveguides (in integrated optics) is used to estimate, with sufficient accuracy, the position of Wood singularities, responsible for the more-interesting visual features of a grating. We show how to use such a model to assess color dynamics variations that are due to production and to estimate domains within the space of grating parameters that enable both first- and second-level security features to be implemented simultaneously. All the results are compared with the values obtained by rigorous coupled-wave analysis.

Mechanisms of gene transfer mediated by lipoplexes associated with targeting ligands or pH-sensitive peptides

Association of a targeting ligand such as transferrin, or an endosome disrupting peptide such as GALA, with cationic liposome-DNA complexes ('lipoplexes') results in a significant enhancement of transfection of several cell types (Simões S et al, Gene Therapy 1998; 5: 955-964). Although these strategies can overcome some of the barriers to gene delivery by lipoplexes, the mechanisms by which they actually enhance tranfection is not known. In studies designed to establish the targeting specificity of transferrin, we found that apo-transferrin enhances transfection to the same extent as transferrin, indicating that internalization of the lipoplexes is mostly independent of transferrin receptors. These observations were reinforced by results obtained from competitive inhibition studies either by preincubating the cells with an excess of free ligand or with various 'receptor-blocking' lipoplexes. Transfection of cells in the presence of drugs that interfere with the endocytotic pathway provided additional insights into the mechanisms of gene delivery by transferrin- or GALA-lipoplexes. Our results indicate that transferrin-lipoplexes deliver transgenes by endocytosis primarily via a non-receptor-mediated mechanism, and that acidification of the endosomes is partially involved in this process.

Interaction of cationic liposomes and their DNA complexes with monocytic leukemia cells

Cationic liposomes complexed with DNA have been used extensively as non-viral vectors for the intracellular delivery of reporter or therapeutic genes in culture and in vivo. We examined the relationship between the characteristics of the lipoplexes, their mode of interaction with monocytic THP-1 cells and their ability to transfect these cells. We determined the size and zeta potential of cationic liposomes (composed of 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP) and its mixtures with neutral lipids), and lipoplexes at different (+/-) charge ratios. As the (+/-) charge ratio of the lipoplexes decreased to (1/1), a significant reduction in zeta potential and an increase in size was observed. The increase in size resulted from fusion between liposomes promoted by DNA, as demonstrated by a lipid mixing assay, and from aggregation of the complexes. Interaction of liposomes and lipoplexes with THP-1 cells was assessed by monitoring lipid mixing ('fusion') as well as binding and cell association. While no lipid mixing was observed with the 1/2 (+/-) lipid/DNA complexes, lipoplexes with higher (+/-) charge ratios underwent significant fusion in conjunction with extensive cell binding. Liposome binding to cells was dependent on the positive charge of the liposomes, and their fusion could be modulated by the co-lipid. DOTAP/phosphatidylethanolamine (1:1) liposomes fused with THP-1 cells, unlike DOTAP/phosphatidylcholine (1:1) liposomes, although both liposome types bound to the cells to a similar extent. The use of inhibitors of endocytosis indicated that fusion of the cationic liposomes with cells occurred mainly at the plasma membrane level. The presence of serum increased the size of the cationic liposomes, but not that of the lipoplexes. Low concentrations of serum (3%) completely inhibited the fusion of cationic liposomes with cells, while inhibiting binding by only 20%. Our results suggest that binding of cationic liposomes and lipoplexes to cells is governed primarily by electrostatic interactions, whereas their fusion is regulated by the lipid composition and sterically favorable interactions with cell surface molecules. In addition our results indicate no correlation between fusion of the lipoplexes with the plasma membrane and the levels of transfection.

Cationic liposomes as gene transfer vectors: barriers to successful application in gene therapy

Despite extensive research in the last decade on the use of cationic liposomes as gene transfer vectors and the development of elegant strategies to enhance their biological activity, these systems are still far from being viable alternatives to the use of viral vectors in gene therapy. Here, we highlight the most recent and relevant discoveries in thisfield, describe the main factors that influence the performance of cationic liposomes, and elucidate the barriers faced by these carrier systems as well as the mechanisms by which they mediate intracellular gene delivery.

Gene delivery mediated by cationic liposomes: from biophysical aspects to enhancement of transfection

Cationic liposomes complexed with DNA have been used extensively as non-viral vectors for the intracellular delivery of reporter or therapeutic genes in culture and in vivo. However, the relationship between the features of the lipid-DNA complexes ('lipoplexes') and their mode of interaction with cells, the efficiency of gene transfer and gene expression remain to be clarified. To gain insights into these aspects, the size and zeta potential of cationic liposomes (composed of 1,2-dioleoyl-3- (trimethylammonium) propane (DOTAP) and its mixture with phosphatidylethanolamine (PE)), and their complexes with DNA at different (+/-) charge ratios were determined. A lipid mixing assay was used to assess the interaction of liposomes and lipoplexes with monocytic leukaemia cells. The use of inhibitors of endocytosis indicated that fusion of the cationic liposomes with cells occurred mainly at the plasma membrane level. However, very limited transfection of these cells was achieved using the above complexes. It is possible that the topology of the cationic liposome-DNA complexes does not allow the entry of DNA into cells through a fusion process at the plasma membrane. In an attempt to enhance transfection mediated by lipoplexes composed of DOTAP and its equimolar mixture with dioleoylphosphatidylethanolamine (DOPE) two different strategies were explored: (i) association of a targeting ligand (transferrin) to the complexes to promote their internalization, presumably by receptor-mediated endocytosis; and (ii) association of synthetic fusogenic peptides (GALA or the influenza haemagglutinin N-terminal peptide HA-2) to the complexes to promote endosomal destabilization and release of the genetic material into the cytoplasm. These strategies were effective in enhancing transfection in a large variety of cells, including epithelial and lymphoid cell lines, as well as human macrophages, especially with the use of optimized lipid/DNA (+/-) charge ratios. Besides leading to high levels of transfection, the ternary complexes of cationic liposomes, DNA, and protein or peptide, have the advantages of being active in the presence of serum and being non-toxic. Moreover, such ternary complexes present a net negative charge and, thus, are likely to alleviate the problems associated with the use of highly positively charged complexes in vivo, such as avid complexation with serum proteins. Overall, the results indicate that these complexes, and their future derivatives, may constitute viable alternatives to viral vectors for gene delivery in vivo.

The utilization of hypnotics in chronic schizophrenics: some critical remarks

Of 23 hospitalized chronic schizophrenic patients, all under neuroleptic medication, hypnotics taken previously for a long time could be totally withdrawn in 16 cases, and in 7 cases, the dosage was diminished by 30%, without any sleep impairment. The gradual reduction of hypnotics was accompanied by a shift of neuroleptic dosage to the evening and bedtime, with reduction of the morning and midday dose, without change of the total daily dose. A significant improvement in the psychic state was observed in 16 patients after withdrawal of the hypnotic; 7 patients showed a slight improvement after reduction of the hypnotic. Monthly or bimonthly reassessment of insomnia in the hospitalized population of chronic schizophrenics is indispensable to avoid the deleterious effects and abuse of hypnotic drugs.

Pharmacokinetic interaction between amitriptyline and neuroleptics

The influence of amitriptyline on the plasma level of various neuroleptics was studied in 25 chronic schizophrenic patients. The study lasted 20 weeks. Patients were kept first 4 weeks on their former neuroleptic medication, with amitriptyline added for 12 subsequent weeks, and withdrawn during the last 4 weeks when only the neuroleptic medication was continued unchanged. The plasma level of neuroleptics was assayed by gas-liquid chromatography, once weekly throughout the study. The amitriptyline plasma level was also evaluated once weekly during the 12 weeks of its administration. The mean neuroleptic plasma values for each 4-week period were pooled together in three groups: aliphatic, piperdine and piperazine phenothiazine derivatives. Amitriptyline provoked some increase of the plasma level of all phenothiazine derivatives. This augmentation was significant only transitorily, however. The putative mechanisms of this neuroleptic tricyclic antidepressant interaction are discussed.

Deanol, lithium and placebo in the treatment of tardive dyskinesia. A double-blind crossover study

A double-blind crossover study on the effects of deanol and lithium carbonate was conducted on a sample of 29 chronic schizophrenic patients with tardive dyskinesia. In addition to his usual treatment with different neuroleptics, each patient received during an 8-week period either deanol, lithium carbonate or placebo. A 4-week wash-out period was inserted between each of the 8-week periods of experimental treatment of the tardive dyskinesia. The administration of either deanol, lithium carbonate or placebo added to the neuroleptic treatment did not produce a statistically significant improvement of tardive dyskinesia in our patient population as a whole. Favorable and unfavorable responses are discussed.

Influence of the antiparkinsonian drugs on the plasma level of neuroleptics

The interaction between various neuroleptics and antiparkinsonian drugs was analyzed by measuring the neuroleptic plasma level before and after withdrawal of antiparkinsonian drugs. The population completing the study consisted of 32 chronic schizophrenics treated with chlorpromazine (8), levomepromazine (14), thioridazine (6), or haloperidol (4). Twenty-five were also receiving benztropine; 4, trihexyphenidyl; and 3, procyclidine. During the first 4 weeks patients remained on neuroleptics and antiparkinsonians, the latter being withdrawn during the 5th week, and the neuroleptics alone being administered during 16 following weeks. The plasma level of neuroleptics was assayed by gas liquid chromatography, once weekly in the morning at two different times. The analysis of variance showed a significant difference in neuroleptic plasma level when patients took neuroleptics only versus the period they had received neuroleptics and antiparkinsonians. The multiple comparison based on Studentized range Q0-05 revealed a significant progressive increase of neuroleptic plasma level during 12 weeks after withdrawal of antiparkinsonian drugs after which a plateau was reached. The hypothetical mechanisms of action of antiparkinsonians on neuroleptic plasma level are discussed.

Sleep analysis during drug-free weekends in chronic schizophrenic patients

The authors made a polygraphic registration of the night sleep in a sample of 14 chronic schizophrenic patients who for several months (mean 8 months) have been on a stable, relatively low maintenance dosage of neuroleptics administered according to the drug-free weekend schedule (two consecutive drug-free days at the weekend). During this treatment none of them showed a relapse or deterioration (BPRS, CGI, and NOSIE rating scales were applied periodically). Their only complaint was of sleep deterioration during the drugfree weekend nights, especially during the second night. The polygraphic night-sleep pattern of each patient was studied during two consecutive weeks. No difference was found between the adaptation night on medication and the consecutive night on medication during the first week, and between the adaptation and readaptation nights on medication during two consecutive weeks. There was no difference in any sleep parameters between the nights on medication and the first drug-free nights. There was a signifcant difference in the total sleep time between the nights on medications and the second drug-free nights. No difference was found in any other sleep parameters in nights analysed as a blocks and in the distribution of NREM and REM stages in the first vs. the second half of the night when B3 was compared with A2. The practical implication is, that to avoid any change in nocturnal behavior it is preferable to withdraw the medication on two nonconsecutive days in the week. The evaluation of both daily and nocturnal behavior seems to be a useful tool in evaluating the first sign of the drug-withdrawal syndrome.

Epidemiology of tardive dyskinesia. Part II

In the part II of an epidemiological study on tardive dyskinesia performed on the same sample of 332 chronic schizophrenic patients (142 males and 190 females), the authors come to the conclusion that the prevalence of tardive dyskinesia is significantly higher if the mean age was higher at the beginning of treatment with sedative or incisive neuroleptics, their combinations (cocktails) and added antiparkinsonian drugs. Age seems to be the most important factor in the prevalence of tardive dyskinesia. The mean longer duration of "incisive" free intervals significantly decreases the prevalence of tardive dyskinesia. Other factors analysed in our sample, especially the total amount of neuroleptics administered, the type of neuroleptics and the mean duration of neuroleptic treatment, do not play a significant role in the prevalence of tardive dyskinesia.

Epidemiology of tardive dyskinesia Part I

We have performed an epidemiological study concerning tardive dyskinesia on a sample of 332 chronic schizophrenic patients (142 males and 190 females, mean age 48.6 years, mean duration of neuroleptic treatment 14.5 years). We could conclude that the age of patients at the time of assessment procedures is the most important variable. The prevalence of tardive dyskinesia was significantly higher in the older population. The significance of an insidious beginning of the illness might be only secondary to the highly significant role of the age. Other factors, such as sex, type of schizophrenia, initial syndrome, present psychic state, organic syndromes and neuroleptic-induced extrapyramidal syndrome, do not seen to play a role in the prevalence of tardive dyskinesia.

Influence of reserpine on all-night sleep pattern in nonlobotomized and lobotomized chronic schizophrenic patients

This study was performed on two groups of schizophrenic patients. One group consisted on nine nonlobotomized patients and the other of nine lobotomized ones. The groups were matched for age, sex, duration of illness, clinical symptoms, type and dose of psychopharmacological treatment. The patients of both groups were administered 1 mg of reserpine half an hour before bedtime, for three successive days. Before reserpine administration the mean percentage time of the NREM stage 4 was significantly higher in the lobotomized group. There was no significant difference in the REM parameters. After three days of reserpine administration in the nonlobotomized group, there was no significant difference in the mean percentage of the NREM stage 4, whereas the mean REM percentage significantly increased and REM latency decreased. In the lobotomized group the same procedure, i.e., three days of reserpine administration, provoked a significant decrease in the mean percentage of the NREM stage 4 and no significant changes in the REM parameters. This difference in reserpine action on sleep in the lobotomized group is discussed.