Healthcare-seeking of medical students: the effect of socio-demographic factors, health behaviour and health status - a cross-sectional study in Hungary

BACKGROUND

Medical students are more likely to have various physical and psychological issues, but less information is available about the healthcare-seeking behaviour for physical and mental health issues. The aim of this study is to determine the factors affecting medical students' healthcare-seeking when visiting a general practitioner (GP) and/or psychologist.

METHODS

688 medical students (326 International and 362 Hungarian,) participated in a cross-sectional study. The information was gathered using a self-administered online questionnaire and covered socio-demographic background, health behaviour, general and mental health status and healthcare-seeking. For analysing adjusted associations, multivariable logistic regression models were used.

RESULTS

Overall, 56.8% of medical students visit the GP; and 17.2%, the psychologist. Hungarian medical students visited the GP with chronic diseases, International medical students were more likely to visit a GP when they encountered sexual activity and had chronic diseases. Moreover, there was a significant correlation between sex, alcohol consumption, and perceived stress in the total sample of psychologist visits. When Hungarian medical students were in their clinical years and had a poor self-rated mental health, they were more likely to visit a psychologist. Whereas female international medical students and those who had poor self-rated mental health were more likely to seek psychological help.

CONCLUSION

Students visit a GP and/or psychologist is associated with a variety of factors, including socio-demographic background, health behaviours, and health issues. Medical schools should encourage help-seeking behaviours and early disclosure of medical students. Their ability to grasp healthcare attitudes and designing treatments will be important for both their academic success and future profession.

Effect of osteoarthritis and its surgical treatment on patients' quality of life: a longitudinal study

BACKGROUND

Osteoarthritis (OA) is one of the primary causes of pain and disability worldwide leading to patients having some of the worst health-related quality of life (QOL). The purpose of our study was to investigate the progression of the generic and disease-specific QOL of osteoarthritic patients going through total hip or knee replacement surgery and the factors that might alter the effect of surgery on QOL.

METHODS

A longitudinal study was performed based on data collected from 120 OA patients who filled in the short version of the WHO's generic measure of quality of life (WHOQOL-BREF) and the disease-specific Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) before and after surgery.

RESULTS

Domains related to physical health status showed relatively lower scores in patients before surgery. Patients reported a significant increase of QOL after surgery in the WHOQOL-BREF physical domain, especially if they were from the younger group (< 65 years, p = 0.022) or had a manual job (p = 0.008). Disease-specific QOL outcome results indicate that overall patients gained significantly better QOL in all domains of the WOMAC score. Patients with hip OA seemed to have the most benefit of their operation as they reported better outcome in WOMAC pain (p = 0.019), stiffness (p = 0.010), physical function domains (p = 0.011) and total score (p = 0.007) compared to knee OA patients.

CONCLUSION

There was a statistically significant improvement in all domains concerning physical functions in the study population. Patients also reported significant improvement in the social relationship domain, which indicates that OA itself as well as its management might have a profound effect on patients' life beyond the reduction of their pain.

[Knowledge and attitudes about vaccinations among medical students during the COVID-19 pandemic]

INTRODUCTION

In Hungary, regarding the age-related mandatory vaccinations, the population is almost 100% vaccinated. In the case of recommended vaccinations, however, the situation is less favourable, and during the COVID-19 pandemic, anti-vaccination sentiment has also appeared in some groups to a greater extent than before. Reducing this is the task of all health professionals.

OBJECTIVE

The exploration of knowledge and attitudes about vaccinations, and the analysis of the characteristics of these factors according to gender, year and vaccine willingness/hesitancy among medical students at the University of Szeged.

METHOD

The cross-sectional study was conducted among first and fourth year medical students of the University, using an online questionnaire, which examined, in addition to sociodemographic characteristics, the administration of influenza and COVID-19 vaccinations, the self-assessment of knowledge about vaccinations, the importance of vaccinations, and student opinions about recommended vaccinations.

RESULTS

Based on the definition of the WHO Strategic Advisory Group, 88.6% of the students belonged to the "vaccine willingness" group, who administered the vaccine against COVID-19 as soon as it became available, while the "vaccine hesitancy" group (11.4%) only asked for the vaccine when vaccination was made mandatory or not even then. According to the model adjusted to gender and year, those who showed willingness to vaccinate were more likely to consider the use of vaccinations, counselling, etc. important than those who were hesitant, while there was no correlation with the self-rating of knowledge. On the basis of the odds ratio of the statements related to the recommended vaccinations, it was possible to identify the opinions associated with vaccine willingness or hesitancy.

DISCUSSION

Overall, student knowledge and attitudes showed a positive picture. On the other hand, it should be emphasized that the misconceptions identified among students showing vaccine hesitancy are the same as the anti-vaccination sentiments found among the general population.

CONCLUSION

During university training, more emphasis should be placed on monitoring the willingness of students to be vaccinated, and on developing knowledge and communication. Orv Hetil. 2023; 164(21): 803-810.

Factors Influencing Pain Management of Patients with Osteoarthritis: A Cross-Sectional Study

Background: Osteoarthritis (OA) is a complex disease associated with chronic pain. Many patients treat their joint pain at a symptomatic level with over-the-counter (OTC) pain medications, often without the knowledge of their physicians. The aim of this study was to provide physicians with data about osteoarthritic patients’ habits of pain management and to examine the explanatory factors of various ways of self-treatment. Methods: A cross-sectional study involving 189 patients with hip or knee OA and scheduled for joint replacement surgery was carried out. Participants filled out a self-administered questionnaire consisting of the Western Ontario and McMaster Universities Osteoarthritis Index and questions about their methods of alleviating pain. Results: 2.6% of patients did not use anything to alleviate their pain, while 63% practiced a non-pharmacological method. Diclofenac was the most frequently used drug, followed by ibuprofen. Profession had the greatest impact on medication habits; patients doing manual work were significantly more likely to take OTC non-steroidal anti-inflammatory drugs and use topical analgesics. Conclusions: Patients utilized a wide variety of pain management techniques. They seemed to use well-known painkillers, even if their side effects were less desirable. Such patients require comprehensive pain management, including educational and behavioural interventions, complemented by topical and oral medication.

The quadrivalent HPV vaccine is protective against genital warts: a meta-analysis

BACKGROUND

The quadrivalent human papillomavirus (HPV) vaccine has been assumed to give protection against genital warts (GW) as well as cervical cancer. Our main question was whether HPV vaccine has any effects on the prevention of GW reported in randomised controlled clinical trials (RCTs) and time-trend analyses.

METHODS

This meta-analysis was performed according to the PRISMA guidelines using the PICO format. We searched in three electronic databases (PubMed, Embase, Cochrane Trials), and assessed heterogeneity using the Q-test and I-squared statistics, meta-regression was also performed. Odds ratios (OR) and their confidence intervals (CI) were calculated. The sensitivity was tested by leave-one-out method. We evaluated the presence of publication bias using the funnel plot graph and the Copas selection model. The strength of evidence was assessed using the GRADE approach.

RESULTS

Eight RCTs (per-protocol populations) and eight time-trend ecological studies were included in this meta-analysis. A significant reduction (pooled OR = 0.03, 95% CI: 0.01-0.09; I-squared = 53.6%) of GW in young women was recorded in RCTs, and in time-trend analyses both in young women (pooled OR = 0.36, CI 95% = 0.26-0.51; I-squared = 98.2%), and in young men (pooled OR = 0.69, 95% CI = 0.61-0.78; I-squared = 92.7%). In subgroup analysis, a significant reduction of the number of GW events was observed especially in women under 21 years (pooled OR = 0.33, 95% CI = 0.17-0.63). Leave-one-out analysis showed that similar results could be obtained after excluding one study, meta-regression did not show significant difference.

CONCLUSIONS

Prophylactic, quadrivalent HPV vaccination can prevent GW in healthy women and men, therefore, it should be included in routine immunization programme.

Abdominal obesity increases metabolic risk factors in non-obese adults: a Hungarian cross-sectional study

Background

The prevalence of abdominal obesity is increasing worldwide. Adults with abdominal obesity have been reported to have increased risk of cardiometabolic disorders.

The aim of this study was to examine whether non-obese subjects (body mass index (BMI) < 25 kg/m²) with abdominal obesity examined in the framework of the Swiss–Hungarian Cooperation Programme had increased metabolic risk compared to participants without abdominal obesity.

Methods

A cross-sectional study was carried out in 5228 non-obese individuals. Data were collected between July 2012 and February 2016. Descriptive statistics, Pearson’s correlation analysis and multiple logistic regression models were applied, odds ratios (OR) with 95% confidence interval (CI) being the outcomes.

Results

607 (11.6%) out of the 5228 non-obese individuals had abdominal obesity. The correlation analysis indicated that the correlation coefficients between BMI and waist circumference (WC) were 0.610 in males and 0.526 in females. In this subgroup, the prevalence of high systolic blood pressure, high fasting blood glucose, and high total cholesterol and triglyceride levels were significantly higher. The logistic regression model based on these data showed significantly higher risk for developing high systolic blood pressure (OR = 1.53; 95% CI = 1.20–1.94), low HDL cholesterol (OR = 2.06; 95% CI = 1.09–3.89), and high trygliceride level (OR = 1.65; 95% CI = 1.27–2.16).

Conclusions

There was a very high, significant, positive correlation between WC and BMI. Abdominal obesity was found to be strongly related to certain metabolic risk factors among non-obese subjects. Hence, measuring waist circumference could be recommended as a simple and efficient tool for screening abdominal obesity and related metabolic risk even in non-obese individuals.

Neurotoxic effects of subchronic intratracheal Mn nanoparticle exposure alone and in combination with other welding fume metals in rats

Manganese (Mn) is a toxic heavy metal exposing workers in various occupational settings and causing, among others, nervous system damage. Metal fumes of welding, a typical source of Mn exposure, contain a complex mixture of metal oxides partly in nanoparticle form. As toxic effects of complex substances cannot be sufficiently understood by examining its components separately, general toxicity and functional neurotoxicity of a main pathogenic welding fume metal, Mn, was examined alone and combined with iron (Fe) and chromium (Cr), also frequently found in fumes. Oxide nanoparticles of Mn, Mn + Fe, Mn + Cr and the triple combination were applied, in aqueous suspension, to the trachea of young adult Wistar rats for 4 weeks. The decrease of body weight gain during treatment, caused by Mn, was counteracted by Fe, but not Cr. At the end of treatment, spontaneous and evoked cortical electrical activity was recorded. Mn caused a shift to higher frequencies, and lengthened evoked potential latency, which were also strongly diminished by co-application of Fe only. The interaction of the metals seen in body weight gain and cortical activity were not related to the measured blood and brain metal levels. Fe might have initiated protective, e.g. antioxidant, mechanisms with a more general effect.

Protective effect of green tea against neuro-functional alterations in rats treated with MnO2 nanoparticles

BACKGROUND

Inhalation of manganese-containing metal fumes at workplaces can cause central nervous damage including a Parkinson-like syndrome. Oxidative stress is likely to be involved in the pathomechanism, due to the presence of nano-sized metal oxide particles with high biological and chemical activity. Oxidative damage of the nervous system could be prevented or ameliorated by properly applied antioxidants, preferably natural ones such as green tea, a popular drink. The aim of this work was to see if orally applied green tea brew could diminish the functional neurotoxicity of manganese dioxide nanoparticles introduced into the airways of rats.

RESULTS

Young adult male Wistar rats were treated intratracheally for 6 weeks with a suspension of synthetic MnO₂ nanoparticles (4 mg/kg body weight), and received green tea brew (1 g leaves 200 mL^-1 water) as drinking fluid. Reduced body weight gain, indicating general toxicity of the nanoparticles, was not influenced by green tea. However, in rats receiving green tea the nervous system effects - changes in the spontaneous and evoked cortical activity and peripheral nerve action potential - were diminished.

CONCLUSION

The use of green tea as a neuroprotective functional drink seems to be a viable approach. © 2016 Society of Chemical Industry.

Size-Dependent Toxicity Differences of Intratracheally Instilled Manganese Oxide Nanoparticles: Conclusions of a Subacute Animal Experiment

Incomplete information on toxicological differences of micro- and nanometer-sized particles raised concerns about the effects of the latter on health and environment. Besides chemical composition, size and surface-to-volume ratio of nanoparticles (NPs) can affect toxicity. To investigate size-dependent toxicity differences, we used particles made of dioxide of the neurotoxic heavy metal manganese (Mn), typically found in inhaled metal fumes, in three size ranges (size A, 9.14 ± 1.98 nm; size B, 42.36 ± 8.06 nm; size C, 118.31 ± 25.37 nm). For modeling the most frequent route of exposure to Mn, NPs were given to rats for 6 weeks by intratracheal instillation. Of each NP size, 3 or 6 mg/kg body weight was given while control animals were vehicle treated. Neurotoxicity was assessed by measuring spontaneous locomotor activity in an open field and by recording spontaneous and evoked electrical activity from the somatosensory cortical area. Mn content of brain, lung, and blood, measured by ICP-MS, were correlated to the observed functional alterations to see the relationship between Mn load and toxic effects. Body weight gain and organ weights were measured as general toxicological indices. The toxicity of size A and size B NPs proved to be stronger compared to size C NPs, seen most clearly in decreased body weight gain and altered spontaneous cortical activity, which were also well correlated to the internal Mn dose. Our results showed strong effect of size on NP toxicity, thus, beyond inappropriateness of toxicity data of micrometer-sized particles in evaluation of NP exposure, differentiation within the nano range may be necessary.

Rutin, a flavonoid phytochemical, ameliorates certain behavioral and electrophysiological alterations and general toxicity of oral arsenic in rats

Arsenic affects large populations and attacks, among others, the nervous system. Waterborne or occupational exposure causes electrophysiological alterations and motor disturbances in humans, and analogous effects were found in animals. Certain phytochemicals may be protective against As-caused damages. In the present study it was investigated whether the flavonoid rutin, applied via the drinking water (2 g/L), ameliorates the effects of arsenic given by gavage (10 mg/kg b.w., in form of NaAsO2) on open field motility, evoked cortical and peripheral electrophysiological activity, and body weight gain in adult male Wistar rats. Body weight gain was significantly reduced from the 4th week of the 6 weeks arsenic treatment and this effect was largely abolished by rutin in the combination treatment group. Rats treated by arsenic alone showed decreased open field motility; latency of the cortical evoked potentials increased and peripheral nerve conduction velocity decreased. These functional alterations were also counteracted by co-administration of rutin, and both the antioxidant and the chelating activity of rutin might have contributed to the ameliorative effect. These results are apparently novel and support the potential role of natural agents in preserving human health in a contaminated environment.

Green tea and vitamin C ameliorate some neuro-functional and biochemical signs of arsenic toxicity in rats

BACKGROUND/OBJECTIVES

Nervous system damage is one of the consequences of oral exposure to waterborne inorganic arsenic. In this work, the role of oxidative status in the neurotoxicity of arsenic and the possible role of two foodborne antioxidants in ameliorating arsenic-related oxidative stress were investigated.

METHODS

Male Wistar rats were given 10 mg/kg b.w. of trivalent inorganic arsenic (in the form of NaAsO2), 5 day/week for 6 weeks by gavage, combined with vitamin C solution (1 g/l) or green tea infusion (2.5 g in 500 ml boiled water) as antioxidants given in the drinking fluid.

RESULTS

Body weight gain was reduced by arsenic from the second week and the antioxidants had no effect on that. Cortical evoked potentials had increased latency, tail nerve conduction velocity was reduced, and this latter effect was counteracted by the antioxidants. The effect of green tea was stronger than that of vitamin C, and green tea also diminished lipid peroxidation induced by As. There was fair correlation between brain As levels, electrophysiological changes, and lipid peroxidation, suggesting a causal relationship.

DISCUSSION

Natural antioxidants might be useful in the protection of the central nervous system against the toxicity of oral As.

General and electrophysiological toxic effects of manganese in rats following subacute administration in dissolved and nanoparticle form

In an attempt to model occupational and environmental Mn exposures and their possible interaction, young male Wistar rats were exposed to Mn by oral administration in dissolved form (MnCl(2)·4H(2)O, 14.84 and 59.36 mg/kg b.w.) and by intratracheal application of MnO(2) nanoparticles (2.63 mg/kg b.w.). After 3 and 6 weeks oral, or 3 weeks oral plus 3 weeks intratracheal, exposure, general toxicological, and electrophysiological tests were done. Body weight gain was significantly reduced after 6 and 3 plus 3 weeks exposure, but the effect of the latter on the pace of weight gain was stronger. Organ weights signalized systemic stress and effect on lungs. Changes in evoked electrophysiological responses (cortical sensory evoked potential and nerve action potential) indicated that the 3 plus 3 weeks combined exposure caused equal or higher changes in the latency of these responses than 6 weeks of exposure, although the calculated summed Mn dose in the former case was lower. The results showed the importance of the physicochemical form of Mn in determining the toxic outcome, and suggested that neurofunctional markers of Mn action may indicate the human health effect better than conventional blood Mn measurement.

Heat capacities of dipolar fluids: ferromagnetic colloids

The heat capacities of ferrofluids are investigated using a thermodynamic perturbation theory approach and the NVT and NpT Monte Carlo simulation methods. The systems studied are considered as one-, three-, and five-component dipolar mixtures modeled by the Stockmayer interaction potential. The isochoric and isobaric heat capacities are calculated and compared with the data determined for a monodisperse equivalent of the system.

UV-B radiation induced exchange of the D1 reaction centre subunits produced from the psbA2 and psbA3 genes in the Cyanobacterium synechocystis sp. PCC 6803

UV-B irradiation of Synechocystis 6803 cells inhibits photosystem II activity, which can be restored via de novo synthesis of the D1 (and D2) reaction center subunits. Recently we have shown that of the two psbA genes that encode identical D1 proteins in Synechocystis 6803, UV-B preferentially enhances the transcription of psbA3 compared to that of psbA2 [Máté, Z., Sass, L., Szekeres, M., Vass, I. and Nagy, F. (1998) J. Biol. Chem. 273, 17439-17444]. Here we studied the effect of UV-B on the synthesis of the D1 protein from the psbA2 and psbA3 genes in the P7 mutant of Synechocystis 6803. In this mutant, psbA2 carries the Ala251-->Val point mutation, which confers resistance to the photosystem II electron transport inhibitor metribuzin, but psbA3 is the same as in the wild-type. By applying variable chlorophyll fluorescence measurements to distinguish between metribuzin-sensitive and metribuzin-resistant photosystem II centers we quantified the amount of the D1 protein produced from each of the psbA3 and psbA2 genes. When the cells were exposed to UV-B light, the fraction of D1 protein produced from the psbA3 gene was increased from 15-20 to 32-40% of the total D1. This effect was reversible by transferring the cells to visible light. The rate of D1 production from psbA3 increased with increasing UV-B intensities, and was a transient phenomenon at low UV-B levels (0.1 microE x m-2 x s-1). It is concluded that the enhancement of psbA3 gene transcription by UV-B light leads to enhanced D1 protein synthesis from this gene. Our findings demonstrate that the main role of psbA3 transcription activated by UV-B is to increase the size of the psbA mRNA pool available for translation when a rapid repair of the D1 protein is needed under UV-B stress.

UV-B induced differential transcription of psbD genes encoding the D2 protein of Photosystem II in the cyanobacterium Synechocystis 6803

UV-B irradiation of intact Synechocystis sp. PCC 6803 cells results in the loss of Photosystem II activity, which can be repaired via de novo synthesis of the D1 and D2 reaction center subunits. A key step in the repair process is the differential transcription of the psbA2 and psbA3 genes, coding for identical D1 polypeptides [Máté et al. (1998) J Biol Chem 273: 17439-17444]. In the present work, we investigated for the first time the effect of UV-B irradiation on the transcription of the psbD1 and psbD2 genes encoding identical D2 polypeptides. By using gene-specific S1 nuclease protection assay we showed differential UV-B induced transcription of the two psbD genes: the level of psbD1 mRNA was increased 1.5-2 fold, whereas the accumulation of psbD2 mRNA was 5-7 fold. The induction of psbD2 transcript accumulation by low intensity light was specific for the UV-B range. UV-A emission from the applied UV source, as well as 100 muE m(-2) s(-1) white light had negligible effect. Increase in the psbD2 mRNA level was observed at very low UV-B intensities, which did not cause damage to the function and protein structure of PS II. Expression patterns of chimeric genes containing the promoter regions of the psbD1, psbD2 genes fused to the firefly luciferase (luc) reporter gene showed similar induction as observed for the endogenous psbD genes. Our findings demonstrate that UV-B radiation induces differential expression of the of the psbD1 and psbD2 genes. We propose that the primarily expressed psbD2 serves as a UV stress gene and participates in a rapid defense response against UV-B stress. This effect is regulated, at least partially, at the level of transcription.

Prevalence of bovine herpesvirus 1 (BHV-1) infection in Hungarian cattle herds

Hungarian cattle herds were surveyed for bovine herpesvirus 1 (BHV-1) infection by ELISA of milk and serum samples. In 1993, 75% of the large cattle herds (consisting of more than 50 cattle) and all small herds (small-scale producers' stocks), while in 1997 90% of the small herds were included in the survey. In the case of large herds, 79.3% of the herds and 64.1% of the samples tested were found to be positive. Of the small herds, 13.5% and 15.7% tested positive in 1993 and 1997, respectively. The majority of large herds were Holstein-Friesian dairy stocks. Small herds with an infection rate markedly exceeding the average were found in those counties where the small herds had been in close contact with the large-scale farms, or where new herds were established by using animals of uncontrolled infectious bovine rhinotracheitis (IBR) status originating from large farms. Attention is called to the importance of maintaining the IBR-free status of small herds that constitute one-third of the Hungarian cattle population.

UV-B-induced differential transcription of psbA genes encoding the D1 protein of photosystem II in the Cyanobacterium synechocystis 6803

UV-B irradiation of intact Synechocystis sp. PCC 6803 cells results in the loss of photosystem II activity, which can be repaired via de novo synthesis of the D1 (and D2) reaction center subunits. In this study, we investigated the effect of UV-B irradiation on the transcription of the psbA2 and psbA3 genes encoding identical D1 proteins. We show that UV-B irradiation increases the level of psbA2 mRNA 2-3-fold and, more dramatically, it induces a 20-30-fold increase in the accumulation of the psbA3 mRNA even at levels of irradiation too low to produce losses of either photosystem II activity or D1 protein. The induction of psbA3 transcript accumulation is specific for UV-B light (290-330 nm). Low intensity UV-A emission (330-390 nm) and white light induce only a small, at most, 2-3-fold enhancement, whereas no effect of blue light was observed. Expression patterns of chimeric genes containing the promoter regions of the psbA2, psbA3 genes fused to the firefly luciferase (luc) reporter gene indicate that (i) transcription of psbA2/luc and psbA3/luc transgenes was elevated, similarly to that of the endogenous psbA genes, by UV-B irradiation, and that (ii) a short, 80-base pair psbA3 promoter fragment is sufficient to maintain UV-B-induced transcription of the luc reporter gene. Furthermore, our findings indicate that UV-B-induced expression of the psbA2 and psbA3 genes is a defense response against UV-B stress, which is regulated, at least, partially at the level of transcription and does not require active electron transport.

Resistance of reaction centers from Rhodobacter sphaeroides against UV-B radiation. Effects on protein structure and electron transport

Inhibition of electron transport and damage to the protein subunits by ultraviolet-B (UV-B, 280-320 nm) radiation have been studied in isolated reaction centers of the non-sulfur purple bacterium Rhodobacter sphaeroides R26. UV-B irradiation results in the inhibition of charge separation as detected by the loss of the initial amplitude of absorbance change at 430 nm reflecting the formation of the P(+)(QAQB)(-) state. In addition to this effect, the charge recombination accelerates and the damping of the semiquinone oscillation increases in the UV-B irradiated reaction centers. A further effect of UV-B is a 2 fold increase in the half- inhibitory concentration of o-phenanthroline. Some damage to the protein subunits of the RC is also observed as a consequence of UV-B irradiation. This effect is manifested as loss of the L, M and H subunits on Coomassie stained gels, but not accompanied with specific degradation products. The damaging effects of UV-B radiation enhanced in reaction centers where the quinone was semireduced (QB (-)) during UV-B irradiation, but decreased in reaction centers which lacked quinone at the QB binding site. In comparison with Photosystem II of green plant photosynthesis, the bacterial reaction center shows about 40 times lower sensitivity to UV-B radiation concerning the activity loss and 10 times lower sensitivity concerning the extent of reaction center protein damage. It is concluded that the main effect of UV-B radiation in the purple bacterial reaction center occurs at the QAQB quinone acceptor complex by decreasing the binding affinity of QB and shifting the electron equilibration from QAQB (-) to QA (-)QB. The inhibitory effect is likely to be caused by modification of the protein environment around the QB binding pocket and mediated by the semiquinone form of QB. The UV-resistance of the bacterial reaction center compared to Photosystem II indicates that either the QAQB acceptor complex, which is present in both types of reaction centers with similar structure and function, is much less susceptible to UV damage in purple bacteria, or, more likely, that Photosystem II contains UV-B targets which are more sensitive than its quinone complex.

Combined therapy with isoprinosine and CO2 laser microsurgery for the treatment of laryngeal papillomatosis

Recurrent laryngeal papillomas and their potential malignant degenerations in adult patients have been known clinically for about 100 years. An early effective treatment has great importance in preventing possible obstruction of the airway or malignant change. The use of endoscopic microsurgery with the CO2 laser has resulted in a significant improvement in the eradication of papillomatous nodules. The advantages of laser surgery are: better visualization of the larynx to allow more precise and deeper resection of papillomas, limited bleeding, and a reduced possibility of seeding uninvolved mucosa. Although laser surgery is the current method of choice for treating laryngeal papillomatosis, it has not solved completely the problems of recurrences. To make treatment more effective, we have developed a therapeutic regimen that combines laser microsurgery with the immunostimulant methisoprinol (Isoprinosine). Our observations in 18 patients have shown that this combined management was more successful than using a single modility with either the laser or Isoprinosine alone. The combined approach was also effective in recurrent cases, with the timing of the combination influencing the results of the treatment given.