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Purpose: The impact of major trauma is long lasting. Although polytrauma patients are currently identified with the Berlin polytrauma criteria, data on long-term outcomes are not available. In this study, we evaluated the association of trauma classification with long-term outcome in blunt-trauma patients., Methods: A trauma registry of a level I trauma centre was used for patient identification from 1.1.2006 to 31.12.2015. Patients were grouped as follows: (1) all severely injured trauma patients; (2) all severely injured polytrauma patients; 2a) severely injured patients with AIS ≥ 3 on two different body regions (Berlin-); 2b) severely injured patients with polytrauma and a physiological criterion (Berlin+); and (3) a non-polytrauma group. Kaplan-Meier survival analysis was performed to estimate differences in mortality between different groups., Results: We identified 3359 trauma patients for this study. Non-polytrauma was the largest group (2380 [70.9%] patients). A total of 500 (14.9%) patients fulfilled the criteria for Berlin + definition, leaving 479 (14.3%) polytrauma patients in Berlin- group. Berlin + patients had the highest short-term mortality compared with other groups, although the difference in cumulative mortality gradually plateaued compared with the non-polytrauma patient group; at the end of the 10-year follow up, the non-polytrauma group had the greatest mortality due to the high number of patients with traumatic brain injury (TBI)., Conclusion: Excess mortality of polytrauma patients by Berlin definition occurs in the early phase (30-day mortality) and late deaths are rare. TBI causes high early mortality followed by increased long-term mortality., (© 2024. The Author(s).)

Background and Aims: Major trauma impairs health-related quality of life (HRQoL). The aim of this study was the Finnish translation and external validation of the Trauma Quality of Life (TQoL) questionnaire., Patients and Methods: The Finnish version of the TQoL questionnaire and the 15D, a generic HRQoL questionnaire, were sent by mail to 417 patients identified from the Helsinki Trauma Registry., Results: Altogether 222 patients (53.2%) returned the questionnaires. Participants' mean age was 49.9 ± 18.1 years and 68.8% were males. The mean 15D score was significantly lower than that of the age- and sex-standardized general Finnish population (0.817 vs. 0.918, p  < 0.001). The correlation between the Finnish translation and 15D scores was high (0.805). Factor analysis revealed that the Finnish TQoL questionnaire and the 15D have four common factors. Internal validation identified some differences between the Finnish and the original versions., Conclusions: The correlation between the Finnish TQoL questionnaire and the 15D was high. The factor structures of the original and Finnish versions of the TQoL questionnaire were not identical, which may be a consequence of cultural or patient population differences.Implications for rehabilitationTrauma causes a long-term decrease in health-related quality of life (HRQoL), and this impact should be assessed in rehabilitation.The Trauma-Specific Quality of Life (TQoL) questionnaire has many shared features with the generic HRQoL questionnaire, but it also contains features related to post-traumatic disorder syndrome.The TQoL questionnaire is a valid tool for monitoring HRQoL after trauma.

Background: Trauma registries usually report 30-day or in-hospital mortality as an outcome measure. However, some studies criticize this measure as inadequate; the impact of a major trauma could last longer than 1 month after the injury. We studied the long-term mortality of patients who sustained a major trauma., Methods: The Helsinki University Hospital's trauma registry was used for patient identification from 2006 to 2015 (New Injury Severity Score ≥ 16 and blunt mechanism of injury). For each trauma registry patient, 10 control persons matched by age, sex, and county of residency were obtained from the Population Register Center of Finland. Cause of death information was obtained from Statistics Finland., Results: We included 3 557 trauma registry patients and 35 502 control persons. Follow-up ranged from 1 year 7 months to 11 years 7 months. The 1-year mortality was 11 times higher in the trauma-patient group (22% vs. 2%). The long-term (approximately 12 years) mortality after the injury was 2.6 times higher in the trauma-patient group (46% vs. 18%). For patients surviving at least 1 year post-trauma, the mortality at 12 years was 2.2 times higher than in the control group (31% vs. 14 %). The cause of death was a disease in 73.3% of the trauma patients and 93.6% of the controls. Accidents were more often a cause of death in the patient population than in the control population (21.2% vs. 4.1%). Suicide was the cause of death in 3.0% of patients and 1.1% in controls. Several factors associated with increased mortality were identified., Conclusions: Major trauma patients had significantly higher long-term mortality compared to controls. To the best of our knowledge, this is the first study on this subject with a follow up of this duration with patients this severely injured and a cohort this large., Competing Interests: Declaration of Competing Interest The authors declare that we have no conflicts of interest., (Copyright © 2020. Published by Elsevier Ltd.)

Background: In most Western countries, ordinary parental classes exist and have become a well-established form of professional support within midwifery care, even though some of these classes lack evidence of benefits for the parents. A Swedish randomized controlled trial including an intervention as a pilot study, revealed that a type of parental preparatory professional support provided for expectant parents, the "inspirational lecture," showed a tendency to be beneficial for parents' birth experience, and their perceived quality of parental couple relationship. However, there is no previous research on the midwives' experiences from providing the inspirational lecture. Carrying out research on midwives' experiences from providing the lecture, could bring future opportunities to provide a work-integrated learning (WIL) related to professionals' skills, and the pedagogic used. Aim: To elucidate midwives' experiences about providing the inspirational lecture as a care intervention for expectant parents. Methods: Midwives were interviewed and data were analyzed using qualitative content analysis. Results: The midwives strived to put childbirth into a comprehensive and manageable context for the expectant parents, during the inspirational lecture. For this, different approaches were used to make expectant parents understand how the parents themselves can be engaged participants in their own birth. Conclusion and Clinical Implications: The midwives used the inspirational lecture to provide the expectant parents with knowledge about how they, as a parental couple, could cooperate and feel safe in relation to the upcoming birth. This could be understood as if the midwives were striving to facilitate the integrative power of the parental couple, which is the couples' ability to gather their joint power. These results can assist midwives and serve as a reference for providing parental classes for expectant parents with a focus on promoting both the parents' individual as well as mutual skills., (Copyright © 2020 Bäckström, Söderlund, Thorstensson, Mårtensson and Golsäter.)

Background and Aims: We aimed to determine whether the outcome of severely injured patients differs based on admission time (office hours vs. non-office hours) at a tertiary trauma centre without an in-house trauma surgeon consultant available at all times. We also studied subgroups of patients presenting with a New Injury Severity Score (NISS) ≥ 25 and patients experiencing major bleeding., Patients and Methods: This trauma registry study consisted of severely injured patients (NISS > 15) with blunt trauma treated between 2006 and 2017 at a single institute. Causes of deaths were obtained from autopsy reports and classified as resulting from brain injury; exsanguination; multi-organ failure, adult respiratory distress syndrome, or sepsis; or other., Results: Among 1853 patients, 497 (27%) were admitted during office hours (OH) and 1356 (73%) during non-office hours (NOH). Further subgroup analysis consisted of 211 OH and 611 NOH patients with NISS ≥ 25, and 51 OH and 154 NOH patients experiencing major bleeding. The 30-day in-hospital mortality was 3.8%-7.4% lower in the NOH groups. We found no significant differences between the study groups in neither the standardised mortality ratio (SMR, defined as the ratio of observed to expected mortality) nor in the causes of death. In both groups, the primary cause of death resulted from brain injury., Conclusions: We found that arrival time did not affect mortality among patients with severe blunt trauma treated at a tertiary trauma centre without an in-house trauma surgeon consultant available at all times. Thus, this type of unit can maintain a standard of care during non-office hours by investing in precise treatment protocols and continuous education. However, our results do not apply to penetrating trauma injury patients., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: Serious thoracic injuries are associated with high mortality, morbidity, and costs. We compared patient populations, treatment, and survival of serious thoracic injuries in southern Finland and Germany., Methods: Mortality, patient characteristics and treatment modalities were compared over time (2006-2015) in all patients with Abbreviated Injury Scale (AIS) thorax ≥ 3, Injury Severity Score (ISS) > 15, age > 15 years, blunt trauma mechanism, and treatment in Intensive Care Unit (ICU) in Level 1 hospitals included in the Helsinki Trauma Registry (HTR) and the TraumaRegister DGU ® (TR-DGU)., Results: We included 934 patients from HTR and 25 448 patients from TR-DGU. Pre-hospital differences were seen between HTR and TR-DGU; transportation in the presence of a physician in 61% vs. 97%, helicopter use in 2% vs. 42%, intubation in 31% vs. 55%, and thoracostomy in 6% vs. 10% of cases, respectively. The mean hospital length of stay (LOS) and ICU LOS was shorter in HTR vs. TR-DGU (13 vs. 25 days and 9 vs. 12 days, respectively). Our main outcome measure, standardised mortality ratio, was not statistically significantly different [1.01, 95% confidence interval (CI) 0.84-1.18; HTR and 0.97, 95% CI 0.94-1.00; TR-DGU]., Conclusions: Major differences were seen in pre-hospital resources and use of pre-hospital intubation and thoracostomy. In Germany, pre-hospital intubation, tube thoracostomy, and on-scene physicians were more prevalent, while patients stayed longer in ICU and in hospital compared to Finland. Despite these differences in resources and treatment modalities, the standardised mortality of these patients was not statistically different.

Gender studies (GS) has been challenged on epistemological grounds. Here, we compare samples of peer-reviewed academic journal publications written by GS authors and authors from closely related disciplines in the social sciences. The material consisted of 2805 statements from 36 peer-reviewed journal articles, sampled from the Swedish Gender Studies List, which covers >12,000 publications. Each statement was coded as expressing a lack of any of three aspects of objectivity: Bias, Normativity, or Political activism, or as considering any of four realms of explanation for the behaviours or phenomena under study: Biology/genetics, Individual/group differences, Environment/culture, or Societal institutions. Statements in GS publications did to a greater extent express bias and normativity, but not political activism. They did also to a greater extent consider cultural, environmental, social, and societal realms of explanation, and to a lesser extent biological and individual differences explanations.

It is a common practice that patients have a scheduled follow-up visit with radiographs following ankle fracture surgery. The aim of this study was to evaluate whether an early outpatient visit (<3 weeks) after ankle fracture surgery resulted in a change in patient management. For this study, 878 consecutive operatively treated ankle fracture patients with an early outpatient clinical-radiological visit were reviewed. The outcome measure was a change in treatment plan defined as any procedure, medication, or surgical intervention that is not typically implemented during the uncomplicated healing process of an acute fracture. A change in treatment plan was observed in 9.8% of operatively treated ankle fracture patients. The mean age of the patients was 48 years and the mean follow-up time was 64 months. Of the changes in treatment plan, 91% were exclusively due to clinical findings such as infection. Only three of 878 patients required a change in their treatment plan based merely on the findings of the radiographs taken at the outpatient visit. Only 37% of the patients requiring a change in their postoperative management had solicited an unanticipated visit before the scheduled outpatient visit due to clinical problems such as infection or a cast-related issue. Our study showed that every tenth operatively treated ankle fracture patient requires a change in their treatment plan due to a clinical problem such as infection or a cast-related issue. Although at hospital discharge all patients are provided with written instructions on where to contact if problems related to the operated ankle emerge, only one third of the patients are aware of the clinically alarming symptoms and seek care when problems present. Our findings do not support obtaining routine radiographs at the early outpatient visit in an ankle fracture patient without clinical signs of a complication., (Copyright © 2016. Published by Elsevier Ltd.)

Aims: The aim of this study was to evaluate the influence of tailored patient education on adherence to tyrosine kinase inhibitor medication among patients with chronic myeloid leukaemia., Background: Management of chronic myeloid leukaemia has changed dramatically during the last decade. While medication adherence is crucial to clinical response, little is known about how to improve patients' adherence., Design: Randomized multicentre intervention study., Methods: The study was conducted between June 2012-August 2014. Eighty-six patients with chronic myeloid leukaemia who had been on tyrosine kinase inhibitor medication for at least six months from eight hospitals were randomized into intervention and control groups. Intervention combined nurse-conducted medication counselling, an information booklet, video and website and text message reminders. Patients were interviewed to assess medication adherence using Morisky's 8-Item Medication Adherence Scale at baseline and nine months., Results: Medication adherence improved with the adherence aids used. At nine months, 51% of patients were highly adherent in the intervention group, compared with 21% in the control group. Adherence improved for a higher proportion of patients in the intervention group than the control group (49% vs. 18%). Morisky's score decreased in almost half of control group cases. Patients were most satisfied with face-to-face counselling (86%) and the information booklet (83%) and least satisfied with text messages (9%)., Conclusion: Tailored patient education improved the medication adherence of patients with chronic myeloid leukaemia. Without this, adherence behaviour tended to decline. Personal communication with a nurse proved to be an essential part of adherence support and should not be ignored., (© 2016 John Wiley & Sons Ltd.)

Contacts between humans and animals inevitably involve encounters possibly resulting in the human being injured. During the period of 2000 to 2014 almost 90 people died in this kind of conflict in Finland. Of these deaths, one third were associated with horses. In addition, over the same period 85 people died in traffic accidents in which an animal was hit by a car. Accidents requiring hospitalization occurred for approx. 8 000 people.

Spinopelvic dissociation is a rare high-energy injury, which is frequently associated with lumbosacral plexus and cauda equina deficits. During an 18-year period, 36 consecutive patients with a H-type sacral fracture and spinopelvic dissociation were treated using lumbopelvic fixation with a minimum follow-up of 18 months. We evaluated factors prognostic of outcome after standardised surgical fixation and neural decompression. Neurological recovery was assessed by Gibbons’ criteria. Pelvis Outcome Scale (POS clinical score) was used to evaluate the clinical outcome. Despite excellent or good radiological results in the vertical components of the sacral fractures having been achieved in all patients, 15 patients (42%) had a poor clinical outcome. The degree of initial translational displacement in the transverse sacral fracture was significantly associated with neurological recovery (as defined by a change in Gibbons score) (p = 0.038) and final POS clinical score (p < 0.001). Both neurological recovery and clinical outcome were worse in patients with completely displaced fractures than in patients with a partially displaced sacral fracture. The degree of residual translational displacement and kyphosis in the transverse sacral fracture were also associated with clinical outcome (POS clinical score) (p = 0.011 and p = 0,018, respectively). However, Roy-Camille classification (type 2 vs. type 3), age, gender, ISS, timing of surgery, and sacral laminectomy did not have a statistically significant association with the outcome. Based on the results, Roy-Camille sacral fracture classification (type 2 vs. type 3) was not prognostic of neurological impairment. Thus further categorisation of the transverse sacral fractures as partially displaced or completely displaced could be used to predict the rate of neurological recovery following lumbopelvic fixation. Accurate reduction of all sacral fracture components seems to be associated with better clinical outcome.

Objective: to investigate the reliability and validity of the Acceptance Symptom Assessment Scale (ASAS) in assessing labour pain., Design: a test-retest approach was used to assess reliability and validity., Setting: labour ward with approximately 2,400 deliveries annually in western part of Sweden., Participants: forty-seven pregnant women in the latent or active phase of labour., Methods: a total of five pain assessments with both the ASAS and the VAS were conducted in three sessions., Main Outcome Measures: correlation between ASAS and VAS., Findings: both scales demonstrated high and significant test-retest correlations (r=0.83-0.92; p<0.001). High and significant alternative-form reliability correlations (r=0.76-0.93, p<0.001) were found between ASAS and VAS ratings at all five assessments. Construct validity was established when both the ASAS and the VAS identified a pain reduction (p<0.001) 2 hrs after birth, compared to the previous assessment. Over two-thirds of the women preferred the ASAS to the VAS, mainly (n=30) because the ASAS provided more choices relating to the pain experience, making it possible to label pain acceptable/unacceptable., Conclusions: the ASAS is interchangeable with the VAS for assessing labour pain. Over two-thirds of the women preferred it to the VAS., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: The aim of the present study was to characterise traumatic deaths occurring in the emergency room (ER) and to assess retrospectively the quality of given emergency care by evaluating whether any of the deaths could be identified as potentially preventable., Methods: All consecutive deaths of trauma patients between 1 January 1998 and 31 December 2006 in the ER of the Töölö Hospital Trauma Centre were retrospectively reviewed. The inclusion criterion was death of a trauma patient occurring in the ER. Both the pre- and inhospital medical charts and the autopsy reports of the patients were reviewed., Results: A total of 115 patients fulfilled the inclusion criteria, and the autopsy reports were obtained for all of these cases (100%). The patients were mainly males (n = 84; 73%), and the median age of the patients was 51 years (range 1-93 years). The average injury severity score (ISS) was 34.6. Blunt trauma was the most common type of injury in the study population. A total of 115 injuries in 50 patients were missed in both the clinical and radiological surveys in the ER, i.e., a missed injury was identified in 43% of the cases. Of these patients, 15.7% had a clinically significant missed injury (AIS ≥ 4). Based on our review of all available material, we consider that 11 deaths (9.6%) were potentially preventable., Conclusions: Missed injuries did not play a major role in the preventable deaths. Seven potentially preventable deaths were considered to be failures in the surgical decision-making process, resulting in futile non-operative treatment or a delay in surgical bleeding control.

Predator cues and diet, when studied separately, have been shown to affect body shape of organisms. Previous studies show that the morphological responses to predator absence/presence and diet may be similar, and hence could confound the interpretation of the causes of morphological differences found between groups of individuals. In this study, we simultaneously examined the effect of these two factors on body shape and performance in crucian carp in a laboratory experiment. Crucian carp (Carassius carassius) developed a shallow body shape when feeding on zooplankton prey and a deep body shape when feeding on benthic chironomids. In addition, the presence of chemical cues from a pike predator affected body shape, where a shallow body shape was developed in the absence of pike and a deep body shape was developed in the presence of pike. Foraging activity was low in the presence of pike cues and when chironomids were given as prey. Our results thereby suggest that the change in body shape could be indirectly mediated through differences in foraging activity. Finally, the induced body shape changes affected the foraging efficiency, where crucians raised on a zooplankton diet or in the absence of pike cues had a higher foraging success on zooplankton compared to crucian raised on a chironomid diet or in the presence of pike. These results suggest that body changes in response to predators can be associated with a cost, in terms of competition for resources.

Lysobisphosphatidic acid (LBPA) can be regarded to represent a unique derivative of phosphatidylglycerol. This lipid is highly enriched in late endosomes where it can comprise up to 10-15 mol% of all lipids and in these membranes, LBPA appears to be segregated into microdomains. We studied the thermotropic behavior of pure dioleoyl-LBPA mono- and bilayers using Langmuir-lipid monolayers, electron microscopy, differential scanning calorimetry (DSC), and fluorescence spectroscopy. LBPA formed metastable, liquid-expanded monolayers at an air/buffer interface, and its compression isotherms lacked any indication for structural phase transitions. Neat LBPA formed multilamellar vesicles with no structural transitions or phase transitions between 10 and 80 degrees C at a pH range of 3.0-7.4. We then proceeded to study mixed LBPA/dipalmitoylphosphatidylcholine (DPPC) bilayers by DSC and fluorescence spectroscopy. Incorporating increasing amounts of LBPA (up to X(LBPA) (molar fraction)=0.10) decreased the co-operativity of the main transition for DPPC, and a decrease in the main phase transition as well as pretransition temperature of DPPC was observed yet with no effect on the enthalpy of this transition. In keeping with the DSC data for DPPC, 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC)/LBPA mixed bilayers were more fluid, and no evidence for lateral phase segregation was observed. These results were confirmed using fluorescence microscopy of Langmuir-lipid films composed of POPC and LBPA up to X(LBPA)=0.50 with no evidence for lateral phase separation. As late endosomes are eminently acidic, we examined the effect of lowering pH on lateral organization of mixed PC/LBPA bilayers by DSC and fluorescence spectroscopy. Even at pH 3.0, we find no evidence of LBPA-induced microdomain formation at LBPA contents found in cellular organelles.

The membrane interactions of pregnanolone, an intravenous general anesthetic steroid, were characterized using fluorescence spectroscopy and monolayer technique. di-8-ANEPPS [4-[2-[6-(dioctylamino)-2-naphthalenyl]ethenyl]-1-(3-sulfopropyl)-pyridinium], a membrane dipole potential (Psi)-sensitive probe, revealed pregnanolone to decrease Psi similarly as reported previously for other anesthetics. The decrement in Psi was approximately 16 and 10 mV in dipalmitoylphosphatidylcholine (DPPC) and DPPC/cholesterol (90:10, mol/mol) vesicles, respectively. Diphenylhexatriene anisotropy indicated pregnanolone to have a negligible effect on the acyl chain order. In contrast, substantial changes were observed for the fluorescent dye Prodan, thus suggesting pregnanolone to reside in the interfacial region of lipid bilayers. Langmuir balance studies indicated increased association of pregnanolone to DPPC monolayers containing cholesterol or 6-ketocholestanol at surface pressures pi > 20 mN/m as well as to monolayers of the unsaturated 1-palmitoyl-2-oleoylphosphatidylcholine. In the same surface pressure range, the addition of phloretin, which decreases Psi, reduced the penetration of pregnanolone into the monolayers. These results suggest that membrane partitioning of pregnanolone is influenced by the spacing of the phosphocholine head groups as well as by membrane dipole potential. The latter can be explained in terms of electrostatic dipole-dipole interactions between pregnanolone and the membrane lipids with their associated water molecules. Considering the universal nature of these interactions, they are likely to affect membrane partitioning of most, if not all, weakly amphiphilic drugs.

The present study describes a novel in vitro platform for physicochemical profiling of compounds, based on their impact on the air/water interfacial tension. Interfacial partitioning coefficient, cross-sectional area, and critical micelle concentration were derived from the Gibbs adsorption isotherms recorded for 76 structurally diverse drugs. An approximation for the membrane partitioning coefficient, K(memb), is introduced and calculated for the measured compounds. This methodology provides a fully automatic, high-throughput screening technique for compound characterization, yielding precise thermodynamic information on the partitioning behavior of molecules at air/water interfaces, which can be directly related to their anisotropic interaction with lipid bilayers in biological membranes. The latter represents the barrier for the passive entry of compounds into cells. The surface activity profiles are shown to correlate to the ability of the compounds to pass passively through the blood-brain barrier.

The effects of three so-called kosmotropic solutes, namely, betaine, sucrose, and choline chloride on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine large unilamellar vesicles, were studied by measuring the generalized polarization (GP) for the fluorescence emission of the membrane partitioning probe Laurdan. The latter has been shown to be sensitive to the depth of water penetration into phospholipid bilayers. At equal osmotic pressures the three solutes produced different increments in GP, with a qualitative positive correlation. However, the increments in GP correlated also quantitatively with the increase of air-water surface tension caused by the three kosmotropes. Our findings suggest surface tension to determine the impact of these solutes on the lateral packing of the lipid bilayer. Based on the changes in area/lipid at different surface tensions, the equilibrium lateral pressure for a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer at 25 degrees C was estimated to be approximately 34 mN/m.

Poly(ethylene glycol)(2000)C(20)ceramide (PEG-Cer) containing monolayers at an air/water interface were characterized by measuring their surface pressure versus area/molecule (pi-A) and surface potential versus area/molecule (Delta V-A) isotherms. The behavior of pi-A as well as Delta V versus lipid density (Delta V-n) and Delta V-pi isotherms for PEG-Cer are in keeping with two transitions of the lipopolymer, starting at pi approximately equal to 9 and 21 mN/m. We also investigated the effects of PEG-Cer on the binding of adriamycin, cytochrome c and bovine serum albumin to monolayers containing varying mole fractions X of PEG-Cer. PEG-Cer impedes the penetration of these ligands into lipid monolayers with similar effects at both X = 0.04 and 0.08. This effect of PEG-Cer depends on the conformation of the lipopolymer and the interactions between the lipid surface and the surface-interacting molecule as well as the size of the latter.

Macroscopic consequences of the formation of diacylglycerol by phospholipase C (PC-PLC) in giant 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) unilamellar vesicles (GUVs, diameter 10-100 microm) were studied by phase contrast and fluorescence microscopy. PC-PLC caused a series of fast stepwise shrinkages of fluid SOPC GUVs, continuing until the vesicle disappeared beyond the optical resolution of the microscope. The presence of N-palmitoyl-sphingomyelin (mole fraction X = 0.25) in the GUVs did not affect the outcome of the PC-PLC reaction. In addition to hydrolysis, PC-PLC induced adhesion of vicinal vesicles. When multilamellar SOPC vesicles were used only a minor decrease in their diameter was evident suggesting that PC-PLC can exert its hydrolytic activity only in the outer monolayer. A series of stepwise shrinkages was observed also for 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) GUVs above their main phase transition temperature, T(m), i.e., when the bilayer is in the liquid crystalline state. However, this process was not observed for DMPC GUVs in the gel state, below T(m). These results are supported by the enhanced activity of PC-PLC upon exceeding T(m) of DMPC large unilamellar vesicles (diameter approximately 0.1 microm) used as a substrate. Studies on SOPC monolayers revealed that PC-PLC can exert its hydrolytic activity only at surface pressures below approximately 30 mN/m. Accordingly, the lack of changes in the gel state DMPC GUVs could be explained by the equilibrium lateral pressure in these vesicles exceeding this critical value.

The interactions of three neuroleptic drugs, clozapine (CLZ), chlorpromazine (CPZ), and haloperidol (HPD) with phospholipids were compared using DSC and Langmuir balance. Main emphasis was on the drug-induced effects on the lateral organization of lipid mixtures of the saturated zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and the unsaturated acidic phosphatidylserine, brainPS. In multilamellar vesicles (MLV) phase separation was observed by DSC at X(PS)> or =0.05. All three drugs bound to these MLVs, abolishing the pretransition at X(drug)> or =0.03. The main transition temperature (T(m)) decreased almost linearly with increasing contents of the drugs, CLZ having the smallest effect. In distinction from the other two drugs, CLZ abolished the phase separation evident in the endotherms for DPPC/brainPS (X(PS)=0.05) MLVs. Compression isotherms of DPPC/brainPS/drug (X(PS)=X(drug)=0.05) monolayers revealed the neuroleptics to increase the average area/molecule, CLZ being the most effective. Penetration into brainPS monolayers showed strong interactions between the three drugs and this acidic phospholipid (in decreasing order CPZ>HPD>CLZ). Hydrophobic interactions demonstrated using neutral eggPC monolayers decreased in a different order, CLZ>CPZ>HPD. Fluorescence microscopy revealed domain morphology of DPPC/brainPS monolayers to be modulated by these drugs, increasing the gel-fluid domain boundary length in the phase coexistence region. To conclude, our data support the view that membrane-partitioning drugs could exert part of their effects by changing the lateral organization and thus also the functions of biomembranes.

We have recently described a novel cyclic peptide inhibitor CTTHWGFTLC (CTT) for matrix metalloproteinases (MMP)-2 and MMP-9, also called type IV collagenases or gelatinases (E. Koivunen et al., NAT: BIOTECHNOL:, 17: 768-774, 1999). As indicated by its amino acid composition, CTT is hydrophobic, and its partitioning into phospholipid films could be verified by the monolayer technique. Augmented fluorescence emission anisotropy (from 0.064 to 0.349) and reduced collisional quenching by I(-) of the Trp residue in CTT was evident in the presence of unilamellar phosphatidylcholine/phosphatidylethanolamine liposomes, revealing the association of CTT with the lipid bilayers. Gelatinases are potential targets of therapeutic intervention in cancer, and inhibitors of these enzymes can prevent tumor progression in animal models. CTT enhanced 3- to 4-fold the cellular uptake of liposome-encapsulated water-soluble fluorescent marker, rhodamine B by gelatinase-expressing cells. Gelatinase targeting seems to be essential, as modified peptides that were less potent gelatinase inhibitors were also less efficient in promoting the cellular uptake of liposomes. Augmented killing ( approximately 4-fold) of U937 leukemia and HT1080 sarcoma cells was obtained by the CTT-enhanced delivery of Adriamycin-containing liposomes, compared with control liposomes administered without the peptide. These results suggest a novel type of utility for small gelatinase inhibitors in targeted cancer therapy.

A stopped-flow spectrofluorometer equipped with a rapid scanning emission monochromator was utilized to monitor the binding of adriamycin to phospholipid liposomes. The latter process is evident as a decrease in fluorescence emission from a trace amount of a pyrene-labeled phospholipid analog (PPDPG, 1-palmitoyl-2-[(6-pyren-1-yl)]decanoyl-sn-glycero-3-phospho-rac-++ +glyce rol) used as a donor for resonance energy transfer to adriamycin. For zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes, fluorescence decay was slow, with a half-time t1/2 of approximately 2 s. When the mole fraction of the acidic phospholipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-rac-glycerol (POPG), was increased to XPG >/= 0.04, the decay of fluorescence became double exponential, and an additional, significantly faster process with t1/2 in the range between 2 and 4 ms was observed. Subsequently, as XPG was increased further, the amplitude of the fast process increased, whereas the slower process was attenuated, its t1/2 increasing to 20 s. Increasing [NaCl] above 50 mM or [CaCl2] above 150 microM abolished the fast component, thus confirming this interaction to be electrostatic. The critical dependence of the fast component on XPG allows the use of this process to probe the organization of acidic phospholipids in liposomes. This was demonstrated with 1, 2-palmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes incorporating PPDPG (XPPDPG = 0.03), i.e., conditions where XPG in fluid bilayers is below the required threshold yielding the fast component. In keeping with the presence of clusters of PPDPG, the fast component was observed for gel-state liposomes. At approximately 34 degreesC (i.e., 6 degrees below Tm), the slower fluorescence decay also appeared, and it was seen throughout the main phase transition region as well as in the liquid-crystalline state. The fluorescence decay behavior at temperatures below, above, and at the main phase transition temperature is interpreted in terms of thermal density fluctuations and an intermediate state between gel and liquid-crystalline states being involved in the phospholipid main phase transition. This is the first observation of a cluster constituted by acidic phospholipids controlling the membrane association of a drug.

Cyclosporin A (CsA) is a highly hydrophobic drug used to prevent graft rejection after organ transplantation. Interactions of CsA with phosphatidylcholine as well as with binary mixtures containing phosphatidylcholine and cholesterol were investigated by measuring the penetration of CsA into lipid monolayers at an air/water interface, by differential scanning calorimetry, and by imaging with fluorescence microscopy the effects of CsA on the lateral distribution of a fluorescent probe, 1-palmitoyl-2-(N-4-nitrobenz-2-oxa-1, 3-diazol)aminocaproyl-phosphocholine, in monolayers. Film penetration studies revealed the association of CsA with lipids to be a biphasic process. Cholesterol diminished the intercalation of CsA into the monolayer at surface pressures of >19 mN/m. CsA broadened the main transition of dimyristoylphosphatidylcholine (DMPC)/beta-cholesterol (10:1, mol/mol) multilamellar vesicles. The behavior of the transition enthalpy was more complex; the behavior of DMPC/beta-cholesterol multilamellar vesicles in the XCsA of 0 to 0.1 showed at most ratios a increase, but several well distinct dips were observed. The results are interpreted in terms of regular structures in tertiary alloy. Influence of CsA on lateral organization could be verified for lipid domains observed by fluorescence microscopy of lipid monolayers. More specifically, CsA altered the distribution of 1-palmitoyl-2-(N-4-nitrobenz-2-oxa-1, 3-diazol)aminocaproyl-phosphocholine in a dipalmitoylphosphatidylcholine film and in DPPC/beta-cholesterol (88:10, mol/mol) mixtures in a manner that suggests that CsA partitions into the boundaries between fluid and gel domains. To our knowledge, this constitutes the first demonstration of a change in lipid domain morphology to be induced by a drug molecule.