Factors affecting progression to permanent atrial fibrillation in an unselected population of patients with non-permanent form of atrial fibrillation

Background

Natural history of atrial fibrillation (AF) shows a progression of arrhythmia from non-permanent to permanent AF. Permanent AF was found associated with a worse prognosis than non-permanent one.

Aim

To assess the factors associated with progression to permanent AF in an unselected population of AF patients with non-permanent AF.

Methods

In this prospective study we enrolled in- as well as out-patients with non-permanent AF and age ≥18 years, with at least one episode of ECG-documented AF within 1 year. The patients were followed-up at 1 month and every 6 months thereafter.

Results

Out of 523 patients, 314 (60%) were in non-permanent AF (80 [25.5%] paroxysmal AF, 165 [52.5%] persistent AF, 69 [2%] first diagnosed AF), mostly male (188, 59.9%), median age 71 years (IQ range 62–77), median CHA2DS2VASc 3 (1–4), median HATCH score 1 (1–2). After a median follow-up of 701 (IQ range 437–902) days, 66 patients (21%) showed permanent AF.

CHA2DS2VASc and HATCH scores were incrementally associated to progression to permanent AF (CHA2DS2VASc χ2 p=0.001; HATCH χ2 p=0.017; p for trend CHA2DS2VASc <0.001, HATCH p=0.001).

At multivariable Cox proportional hazard regression the following variables were significantly associated with AF progression: age (hazard ratio [HR] 1.041; 95% CI: 1.004–1.079; p=0.028), at least moderate left atrial (LA) enlargement (>42 ml/m2) (HR 2.092; 95% CI: 1.132–3.866; p=0.018), antiarrhythmics drugs after the enrollment (HR 0.087; 95% CI: 0.011–0.662; p=0.018), EHRA score >2 (HR 0.351; 95% CI: 0.158–0.779; p=0.010) and Valvular HD (HR 2.161; 95% CI: 1.057–4.420; p=0.035). Adding LA dilation to HATCH score (HATCH-LA) and assigning 2 points based on multivariable Cox regression, HATCH-LA was statistically better in ROC curves in prediction of AF progression vs HATCH score (area under the curve 0.695 vs 0.636; DeLong p=0.0225). Survival-free curves on freedom from permanent AF using as discriminator HATCH-LA score ≤2 vs >2 led to a statistically significant difference (χ2=16.080 p<0.001), but the same was not found for HATCH score (χ2 =3.099; p=0.078).

Conclusions

In patients without permanent AF, progression of AF was independentely related to age, LA dilation, AF symptoms severity, antiarrhythmic drugs and Valvular HD. HATCH score predicted AF progression and adding to it LA dilation (at least moderate) improved patients stratification for the risk of evolution to permanent AF.

Funding Acknowledgement

Type of funding source: None

Method for Assessing Contrast Performance under Lighting Conditions such as Entering a Tunnel on Sunny Day

BACKGROUND

Clinical assessment of dark adaptation is time consuming and requires a specialised instrumentation such as a nyktometer. It is therefore not surprising that dark adaptation is rarely tested in practice. As for the case of testing fitness of a driver, demands on adaptation in daily driving tasks mostly depart from settings in a nyktometer. In daily driving, adaptation is stressed by high and fast transitions of light levels, and the period of time which is relevant to safe driving starts right after a transition and ends several seconds later. In the nyktometer dark adaptation is tested after completion of the adaptation process. RESULTS of a nyktometer test may therefore deliver little information about adaptation shortly after light transitions. In an attempt to develop a clinical test aiming to fulfill both a short measurement time and offering test conditions comparable to conditions in driving, we conducted a preliminary study in which contrast sensitivity thresholds were recorded for light transitions as found in daily driving tasks and for various times after transition onsets. Contrast sensitivity performance is compared to dark adaptation performance as assessed by a myktometer.

MATERIAL AND METHODS

Contrast sensitivity thresholds were recorded in 17 participants by means of a twin projection apparatus. The apparatus enabled the projection of an adapting field and of a Landolt ring both with a variable luminance. Five different stepwise transitions in levels of adapting luminance were tested. All transitions occurred from bright to dark. The Landolt ring was flashed 100 or 500 ms after the transition had occurred. Participants were instructed to report the orientation of the Landolt ring. A Rodenstock Nyktometer, Plate 501, was used to record dark adaptation threshold.

RESULTS

Experimental data from the proposed test revealed a noticeably increasing contrast detection threshold measured in dark adaptation in the stronger transition from 14 000 to 8 cd/m2 than in the weaker transition from 2000 to 8 cd/m2. By raising the dark adaption luminance level from 8 to 60 cd/m2 in the stronger transition case, the contrast detection threshold was then improved by a factor of four. Another main finding showed that for the adaptation process from strong glare stimuli to the dark adaptation, a peak deterioration in contrast sensitivity occurred at the light adaptation level of 6000 cd/m2. Comparing the contrast performance assessed by the proposed test with that of the nyktometer test, there was no clear correlation between the two methods.

CONCLUSIONS

Our suggested method to assess dark adaptation performance proved to be practical in use and, since the patient does not have to spend a long time to attain complete dark adaptation, the method required a short time for measurement. Our negative experience in the use of the myktometer was in agreement with reported experience in the literature.

A field report on self-screening visual acuity using a computerized vision screener

BACKGROUND

Large-scale examinations are costly and time consuming. Costs could be reduced by asking patients to carry out tests by themselves. This study aimed to gain practical experience on how patients handle self-administered acuity tests.

MATERIAL AND METHODS

We developed two computerized self-test acuity screening devices consisting out of a commercially available vision screener, an answering box and a PC. The answering box served to record the responses of the participants and to present verbal instructions to the participants. Participants took acuity tests for far (5 m, OS, OD, OU) and an acuity test for near (40 cm, OU) using the self-test screener. For the reason of privacy personal data like age, gender and habitual correction was entered on a separate PC. The devices were installed in two different locations and run without supervision.

RESULTS

Personal data records of 2528 participants (4% women) were collected in both locations. The age in 45% of the participants ranged between 41 and 50 years. 31% of the participants declared to wear spectacles and 3% contact lenses. 66% of participants declared not to need a correction. A total of 1078 participants completed four acuity tests (OD far, OS far, OU far, OD near) using the self-test screening device. Depending on the acuity test and location, the average duration required to complete one acuity test ranged between 29.7 s to 39.1 s. The total duration for completing the four acuity tests was on average 133 ± 46 s.

CONCLUSIONS

The duration for completing the acuity tests is considered as being short. Made experience speaks in favor of feasibility of self-tests in acuity screening.

Working towards a test for screening visual skills in a complex visual environment

We developed a test for screening visual skills under similar conditions as at workplace. The test was administered to 207 participants, recruited in the working population. Six-digit numbers were super-imposed on a video of a drive and presented for 300 ms in the central visual field and in the periphery. Participants reported whether or not the integer '3' was included in the numbers. Normative data for the test were computed using 150 data sets of participants reporting not to take drugs and with an age ranging between 15 y and 67 y. Participants performed better in the central visual field than in periphery. The test could successfully be completed by participants of all ages without the need of adjustment of settings. Comparison of 46 data sets recorded in participants taking drugs (30 y-68 y) with age matched participants not taking drugs demonstrates an additional potential application of the test. Practitioner Summary: Developed test delivers comparative estimates of visual skills within short time and appears as valuable and cheap complementation to current testing procedures in industrial practice. The test can be used in a preventive and in educative manner to monitor effects of factors like fatigue, sleep deprivation or drug consumption.

Information access at the point of care: what can we learn for designing a mobile CPR system?

OBJECTIVES

Hospitals have started to migrate their paper-based records to computerized patient records (CPR). The majority of today's CPR systems are stationary, which means that physicians use a clinical workstation to access CPR information. But health care professionals need to request and enter information at different locations, for example, on their daily ward round. This suggests the use of mobile computers, enabling an ubiquitous access to needed data. Different studies show that health care professionals are reluctant to use poorly designed mobile CPR systems, as the work at the point of care is very time-pressured and hectic. To design a system with high acceptance, it is essential to obtain empirical insight into the work practices and context in which the mobile CPR system will be used.

METHOD

We investigated the physicians' work with the patient record during their daily round. With the help of a compact notation method, the physicians' interaction with the information system was recorded in real time. Fourteen physicians from three different departments (internal medicine, surgery, and geriatrics) of a middle-sized Swiss hospital participated in our study.

RESULTS

Physicians have clear access preferences when they interact with the patient record during their daily round. There exists a clear profile of access frequencies and patterns, respectively. As an example, approximately 50% of all patient record accesses concern information about medications, vital signs and lab test results.

DISCUSSION/CONCLUSION

A CPR system which is designed to reflect the access frequencies and patterns should improve the efficiency of data entry and retrieval and thus result in a system with high acceptance among physicians in the demanding environment during hospital rounds.

Evaluation of two algorithms for counting forward saccades in a reading task

We compared two algorithms, which are used to assess the number of forward saccades in a reading task from records of eye movements. In one algorithm saccades are detected analysing the velocity of eye movements. The third derivate of eye position in time (jerk) is used in the second algorithm for the detection of saccades. Both algorithms were applied on the same set of data, recorded using 24 subjects reading a German text, which was presented on two different displays. Our subjects read the text at a mean reading speed of 258.5 word/min. Both algorithms were found to produce a similar rate of artefacts in the number of detected saccades (2.5%), provided the threshold for detection (velocity or jerk) is set at an appropriate level and the same level of threshold is applied to all data. In both algorithms, the rate of artefacts increases with increasing distance of the threshold from its optimum. Inter-individual variation of the rate of artefacts increases more pronounced in the algorithm based on jerks. Eye blinks were identified as a major source of artefacts. A remedy is proposed, by means of which the rate of artefacts can be reduced.

[Technical realization of an LCD-based vision test device]

We describe a computer-aided self-test vision screener for testing near and far visual acuity. The device generates images separately for each eye on a LCD. Acuity can be measured in the range between 0.1 and 1.6 for any distance between 0.34 m and 6 m. In addition, it also enables testing for colour deficiency, phoria, stereopsis and contrast sensitivity. The device is fully automatic and enables self-testing of the above mentioned functions. Initial practical application in an industrial environment has demonstrated the practicability of the device.

[Virtual retinal display system with nodal point image of a laser beam: construction example and evaluation of subjective brightness perception]

We investigated the perception of brightness for red monochromatic laser light. For this purpose, a modified virtual retinal display (VRD) was constructed. The modification involved projecting the laser beam into the eye. In our VRD, the laser beam pivots in the nodal point of the eye (badal system). The displayed image therefore does not depend on the refractive state of the eye. Brightness perception was assessed by means of psychophysical experiments. The results of these experiments indicate that perception of brightness at 652 nm increases more rapidly with increasing physical stimulus than does the perception of white light (colour temperature 2'935 K). At a wavelength of 652 nm, an optical power of 79 nW is required to produce an image subtending 2 degrees of equal brightness, as is perceived with an image of about 2'900 cd/m2 subtending 2 degrees.

[Computer-based determination of stereopsis]

AIM

A computer-based approach to assess stereopsis for screening purposes is described. This approach is based on random-dot stereograms (RDS).

METHOD

The TNO test is a common method to assess stereopsis based on red/green anaglyphs and the use of RDS. This technique was transferred to a computer-based platform. To investigate the validity of the computer-based approach, 25 subjects were tested with both the TNO test and the computer-based approach.

RESULTS

With regard to the spectral emission of the monitor screen, accurate separation of red and green for RDS generation was not possible. However, adaptation of the RDS to the colour filters used permitted the best-possible separation. The resolution of the monitor required a viewing distance of 2 m. The results obtained showed no significant differences between the two methods.

CONCLUSIONS

For the computer-based screening, RDS and anaglyphs can be employed. The influence of the spectral emission of the monitor screen and its resolution can be reduced by adapting the RDS colours to the filters used and modifying the viewing distance.

[Effects of presbyopia on clinical phoria]

BACKGROUND

Due to accommodation-vergence cross-link we can expect that presbyopia will affect vergence as well. From investigations of cross-link as function of age one may assess strain of visual system due to presbyopia. Furthermore, this observation will give hints on innervation of ciliary muscle.

MATERIAL AND METHOD

Vergence is assessed as function of stimulus of accommodation in 27 subjects (24-65 years).

RESULTS

Presbyops tend to be exophoric for near vision. Vergence is linked to accommodation by means of a quadratic polynome rather than by a linear function.

CONCLUSIONS

We may expect, that missing vergence strains visual system of presbyops. Results support Hess-Gullstrand theory of presbyopia and indicate a loss of innervation of ciliary muscle with increasing age.

[Computer-based determination of red/green color vision defects]

A commonly used method of investigating colour vision, that is, the ability of the human visual system to discriminate colours, is based on the use of isochromatic colour plates, such as those used in the Ishihara test. The present paper describes a new computer-based method of determining red/green colour vision deficiencies. The method involves the presentation of Ishihara colour plates on a computer monitor. It has been verified experimentally that, despite the differences between the spectral emission of the computer screen and the daylight reflected by the Ishihara plates, the method is capable of distinguishing between subjects with from those without colour vision deficiencies. For screening purposes, the use of a reduced number of plates is suggested. This suggestion makes use of nine instead of 14 plates, and the criterion of two incorrectly recognized plates to determine a colour vision deficiency.

[Video laparoscopy in patients with pain in the right iliac region]

The authors report on their experience of 235 laparotomy operations and 125 laparoscopic operations performed on patients with right lower abdominal pain. Concerning each of these different approaches, the authors analyzed and compared preoperative diagnosis, anatomo-pathological findings, intraoperative and early post operative morbidity and hospital stay. The ratio of negative open-appendectomies was 24.1% (56 cases out of 233). The laparoscopic approach, performed on 88 cases of suspected appendicitis, allowed to document and to treat other pathologies, real causes of the lower right abdominal pain, in 42 cases (47.7%). The rate of conversion from laparoscopic appendectomy to open appendectomy was only 2.19% (2 cases out of 91). The morbidity rate of laparoscopic appendectomy was estimated at 6.5% (4.4% major complications, 2.2% minor complications). The morbidity rate of open appendectomy was estimated at 8.9% (0.4% major complications, 8.5% minor complications). Though the median postoperative stay, after laparotomy approach, was slightly longer (2.6 days versus 2.4 days), the difference was not statistically significant. Based on these results, the authors conclude that the laparoscopic approach should be reserved for fertile female patients, especially when the diagnosis of appendicitis is uncertain.

[Microfluctuations in accommodation]

BACKGROUND

So called microfluctuations of the power of crystalline lens are uncontested in scientific community. However, there are still open questions about possible artefacts which deserve discussion.

PURPOSE

This contribution is intended to reopen discussion of matters concerning fundamentals about microfluctuations of the crystalline lens.

METHOD AND RESULTS

Thoughts are outlined which render characteristics or even existence of microfluctuations questionable.

CONCLUSION

There is still a need for a conclusive experiment to determine existence and role of microfluctuations.

[Computer-based assessment of visual acuity--technical realization]

Testing of visual acuity for distant vision can be computerized by using monitor screens to present optotypes. Because of the limited spatial resolution of conventional monitors, measurement of visual acuity for near vision is not possible. This paper describes a new computer-aided method for the measurement of both near and distant visual acuity. Our approach to the assessment of visual acuity for near vision is based on a recently developed liquid crystal display (a screen, LCD) measuring 10.5 mm x 15 mm. The LCD permits the presentation of optotypes for the measurement of visual acuity between 0.063 and 1.25 at a viewing distance of 40 cm (near/distant). The presentation of optotypes for the assessment of the acuity of distant vision uses a standard 17" monitor that permits visual acuity figures of between 0.032 and 1.6 to be assessed.

[The suitability of various cephalometric planes for the determination of vertical alignment of the head]

Different cephalometric lines or planes may be used to determine vertical head tilt. 94 subjects were used to assess the difference in inclination between the Frankfurt horizontal and Reid's line by means of a photographic method. We found that the inclination of Reid's line differs about 13 degrees from the inclination of the Frankfurt horizontal and depends on the subject's sex but not on their age. Hand held inclinometer are used in most studies for determining the inclination of the head. In our study different experimenters assessed the above mentioned inclinations at our 94 subject's using a hand held inclinometer. It turned out that the results depend statistically significant on the experimenter. Data were compared to the ones assessed using the photographic method. By means of an analysis of variance in which the experimenter is considered, a significant correlation (p < 0.001) between data assessed with the two different methods was found. However, only 51% of the variance can be explained by our model. Variance might be due to inaccuracy in determining some of the points defining the Frankfurt horizontal and Reid's line, i.e. the lower orbit and the centre of the outer ear channel. The inclination of another reference line running from the tragion to the outer canthus was measured using the same subjects and the same experimental procedure as mentioned above. This line is easier to determine than the Frankfurt horizontal or Reid's line as its defining points can be assessed with greater accuracy. The inclination of this differs 10.5 degrees from the one of the Frankfurt horizontal.

Treatment of choroidal neovascularization in age-related macular degeneration with interferon alpha-2a: a short term, nonrandomized pilot study

A total of 11 patients exhibiting in 11 eyes a subfoveal or juxtafoveal choroidal neovascular membrane due to age-related macular degeneration (AMD) were treated with interferon alpha-2a (Roferon) according to a protocol that was designed for an independent, randomized, open-label pilot study to evaluate the efficacy and safety of this therapy. However, none of the patients agreed to be randomized and all elected to be treated. The average follow-up period after treatment was 8.2 months. In 6 of 7 eyes with classic choroidal neovascularization the membrane increased in size during and after treatment. Of these 6 eyes, 5 lost more than 6 lines of visual acuity. In 2 of 4 eyes with occult neovascularization the lesion enlarged. In the other 2 eyes the lesion became atrophic in 1 case and remained stable in size in the other. Visual acuity decreased by 3-9 lines in 3 eyes with occult neovascularization. Of the 11 patients, 2 discontinued interferon treatment after 8 weeks because of severe adverse reactions. From the data collected thus far in this study and in the majority of published series, we conclude that interferon alpha-2a in the dose range of 3-6 million IU given three times weekly over 8-12 weeks is neither effective nor safe for the treatment of subfoveal neovascularization in AMD.

[Personal computer used in visual function screening]

BACKGROUND

The number of medical screenings is increasing. This fact is specially pronounced in the field of occupational health. Due to restricted financial resources and limitations in time there is a need for rationalisation in medical screenings.

MATERIALS AND METHODS

Possible uses of personal computers (PC) enabling organisational and financial benefits in medical screenings are suggested. By means of a test for colour-blindness it is shown how unfavourable technical conditions may be by-passed.

RESULTS AND DISCUSSION

Rationalisation in medical screenings can be achieved when using the PC as a multi-functional screening-device as well as an expert system, measuring apparatus and as a communication-device. Due to a lack of literature it is difficult to discuss possible effects of technical differences between PC-based screenings of visual functions and screenings where "traditional". Reliability, sensitivity and validity is insufficiently investigated for many of the commercial available screening-devices based on a PC.

Direction of gaze and comfort: discovering the relation for the ergonomic optimization of visual tasks

Perceived exertion caused by the extraocular muscles was assessed as a function of the direction of gaze and recorded in 114 subjects using a psychometric method. The results confirm statements in the literature that maximum comfort is achieved when gaze is aimed downwards. We found no correlations between perceived exertion and age or viewing distance. The relationship is relevant to ergonomics, for example in lens fitting and workplace layout.

Central catheter infection by Trichosporon beigelii after autologous blood stem cell transplantation. A case report and review of the literature

A case of localized Trichosporon beigelii infection is reported in a 40-year-old woman with Ph+ chronic granulocyte leukemia who underwent autologous blood stem cell transplantation. On day +14 after autograft, while severely neutropenic, she developed a local infection involving the soft tissues surrounding the central venous catheter (CVC) point of entry into the subclavian vein. Trichosporon beigelii was isolated from culture of the CVC tip; resolution occurred after removal of the CVC, neutrophil recovery and antifungal treatment with amphotericin B and 5-fluorocytosine. To our knowledge this is the first case of CVC localized infection from Trichosporon beigelii after transplantation.

[Eyeglass frame for detection of eye, head movements and pupillary diameter]

Up till now, the simultaneous recording of the movements of the eyes, the movements of the head and the diameter of the pupil required the combined use of several apparatus. In this paper we present a new apparatus developed for the simultaneous recording of the movements of the eyes and of the head, and the diameter of the pupil. The apparatus consists of a portable frame (weight 215 g) a 19" rack containing electronics, and a PC for storing and analyzing the recorded data. In comparison with other systems providing similar measuring possibilities the present apparatus has the advantage of smaller dimensions and lower weight.

Natural history of congestive gastropathy in cirrhosis. The Liver Study Group of V. Cervello Hospital

In a prospective study of the natural history of congestive gastropathy, 212 consecutive cirrhotic patients (75 treated with sclerotherapy) were included. Mean follow-up was 46 months. Mild gastropathy (mosaiclike pattern) was found in 110 patients and severe gastropathy (granular mucosa with cherry spots) was found in 20. Prevalence of Helicobacter pylori, formerly Campylobacter pylori, was 50% in patients without, 43% in those with mild, and 28% in those with severe gastropathy. Congestive gastropathy was significantly more frequent in patients treated with sclerotherapy (83% vs. 50%, P less than 10(-5)). Sixty-month actuarial proportions of patients free of anemia (in the absence of hematemesis or melena), were 17% with severe, 62% with mild, and 93% without gastropathy (P less than 10(-8]. Corresponding figures for overt bleeding were 25%, 73%, and 87% (P less than 10(-7], whereas those for survival were 46%, 72%, and 85% (P = 0.0005), respectively. A multivariate regression analysis supported the following conclusions: (a) sclerotherapy and the presence of large esophageal varices significantly increase the risk of congestive gastropathy, which (b) is a significant risk indicator of both chronic and overt bleeding but does not independently affect survival.

Synthesis, DNA-binding properties, and antitumor activity of novel distamycin derivatives

A group of potential alkylating agents have been synthesized that are structurally related to the oligopeptide antiviral antibiotic distamycin. All derivatives form complexes with native calf-thymus DNA but compounds 2, 3, and 6 give rise to covalent adducts. Cytostatic activity against both human and murine tumor cell lines in vitro is displayed by the new compounds. Compounds 3 and 4 are active on melphalan-resistant L1210 leukemia in mice.

Joint experimental and theoretical investigation of the comparative DNA binding affinities of intercalating anthracycline derivatives

The comparative binding affinities for poly(dA-dT) and poly(dG-dC) of novel antitumor anthracyclines are reported. The data concern, besides the parent compound adriamycin (ADM), 4-demethoxy 6-deoxy 6-aminodaunomycin (II), 9-deoxy-ADM (III), 4-demethyl-6-O-methyl-ADM (IV), and 3'-deamino-3'-hydroxy-4'-epi-ADM (IV). Theoretical computations are performed in parallel for their comparative binding affinities to model double-stranded hexanucleotides, d(GCGCGC)2, d(TATATA)2, and d(CGTACG)2, using the SIBFA (sum of interactions between fragments computed ab inito) procedure. The computations reproduce in a very satisfactory manner the most salient features of the experimental comparative binding affinities. These encompass, in particular, a higher affinity for the d(TATATA)2 oligomer of II than that of ADM, despite the absence of the 14-OH substituent in II, a marked reversal of the CG versus TA sequence selectivity of the neutral compound V, favoring the d(CGCGCG)2 oligomer over the d(TATATA)2 one; and the deleterious effect incurred on the binding affinities by the presence of an O-methyl substituent at position 6 of the chromophore.

Kinetic studies of anthracycline-DNA interaction by fluorescence stopped flow confirm a complex association mechanism

The kinetics of association and dissociation between calf thymus DNA and five anthracyclines, including doxorubicin, daunorubicin, and three synthetic analogues, were investigated with stopped flow using fluorescence detection. The sensitivity of this technique allowed us to work with submicromolar drug concentrations, thus excluding formation of aggregates, and with ratios of DNA base pairs to drug in the range 10-250, where site exclusion effects could be taken into account with a simple correction of DNA concentration and pseudo-first-order conditions were nearly fulfilled. In all cases, both association and dissociation reactions required a sum of three exponential terms to be fitted. However, satisfactory interpretation of reciprocal relaxation times as functions of DNA concentration was only achieved with kinetic models comprising a total of five steps. One of the extra steps was tentatively assigned to formation of a weakly bound, probably nonintercalated species. Another step was deduced from a comparison between results of association and dissociation experiments. The five steps are arranged, for convenience, in an association mechanism with two branches, though other mechanisms cannot be definitely ruled out. Correlation of cytotoxicity data with both association and dissociation rates is not found to be significant. This suggests that other factors must be involved in modulating the different biological properties of the investigated anthracyclines.

[HIV infection: results of 4 years of observation (May 1984-May 1988)- of the admitting department of the V. Cervello Hospital in Palermo]

During a period of four consecutive years (1984-1988) more than one thousand of serum samples were obtained from different "at risk" categories of patients with the aim to investigate on the prevalence of anti-HIV antibodies in these populations. Also HIV antigen and HBV markers were investigated in the same people. Some of them were followed up to monitor the various HIV markers and to cultivate biological material from symptomatic cases. All serological investigations were carried out by means of ELISA methods and the Western Blot technique, to confirm positive results. Data obtained from this study showed that: 1. in our area anti-HIV positive people prevail among intravenous drug addicts (IVDA) (42-48%) in contrast to 3.3% of homosexuals, and in 14-16% of subjects or patients declaring themselves "at risk" without stating what of risk it is. 2. HIV antigen was demonstrated in 5% of symptomatic IVDA patients but only in two cases of anti-HIV negative people. 3. HBV markers were found in all categories examined, prevailing in IVDA subjects (72%). 4. Five percent only of anti-HIV negative people followed up through 2-36 mo. seroconverted while only 39.7% of anti-HIV positive people showed an HIV markers variation (increase, decrease or disappearance) in different periods of time (1-8 mo.). 5. Opportunistic infections were observed in 50% of symptomatic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies of anthracycline--DNA complexes by circular dichroism

A series of doxorubicin and daunorubicin analogues have been investigated in aqueous solution and as DNA-bound forms by means of circular dichroism (c.d.) spectroscopy. The structural variants comprise modifications on the amino sugar, on the aliphatic ring and the side chain of the aglycone moiety, and of the substitution pattern of the anthraquinone chromophore. Results with compounds having conformational constraints interfering with optimal fitting to DNA indicate that stereochemistry and conformation of the aliphatic ring predominantly affect c.d. spectra of anthracyclines in DNA-bound as well as in free form. Conformational correspondence with the known structure of the daunorubicin-oligonucleotide complex is inferred from the spectra of derivatives with modifications at position 6 or 11 in the anthraquinone chromophore. On the other hand, a different binding geometry is postulated for compounds either lacking the 4-methoxy group of daunorubicin (idarubicin and derivatives) or having a phenolic function in its place (carminomycin and derivatives). A possible relation with cytotoxic activity is discussed at a speculative level.

Synthesis, DNA binding and antiviral activity of distamycin analogues containing different heterocyclic moieties

A series of novel distamycin analogues possessing an additional benzene or heterocyclic ring have been synthesised and tested for selective DNA binding properties and antiviral activity. Inhibition of herpes virus in cell culture appears to be related to AT base pair specificity. Some of the new compounds are also more potent than the parent distamycin against Moloney sarcoma virus.

Association of anthracycline derivatives with DNA: a fluorescence study

The DNA affinity for 26 anthracycline derivatives was studied by the quenching fluorescence technique. The stereochemical requirements for DNA intercalation are discussed. The relationship between the DNA affinity and bioactivity is also pointed out.

Self-association of doxorubicin and related compounds in aqueous solution

The dimerization of doxorubicin, daunorubicin, and their 4-demethoxy, 4'-epi, and 4'-deoxy analogues was studied spectrophotometrically. Self-association was found to be influenced by buffer composition and ionic strength. Kd values were 1.3 X 10(4) and 2.3 X 10(4) M-1 for doxorubicin and daunorubicin, respectively, and ranged from 3.8 X 10(3) to 6.1 X 10(3) M-1 for the 4-demethoxy analogues. For 4'-epi- and 4'-deoxydoxorubicin, tetramerization has also been considered. On this basis, values of 2.0 X 10(4) and 2.2 X 10(4) M-1 were found, respectively, for the formation constant of the dimerization process. Stability of the dimeric species appears to be strongly influenced by substitution of the chromophore moiety.