The return of brucellosis

Brucellosis, also known under the names of Undulant fever, Mediterranean fever and Malta fever is closely linked with Malta’s medical history and for long endemic to our Islands. Every reported case was investigated by the medical officers of health who contacted the head of each affected household for an epidemiological enquiry including a food history. All these cases were associated with the consumption of fresh cheeselets made from unpasteurised milk. During the investigation some 900 kgs of cheeselets from 27 producers, 12 wholesalers and 384 retailers were seized and tested.peer-reviewe

Surveillance of Hepatitis B in Malta : a four year trend

Surveillance systems include three fundamental elements of ongoing collection, analysis and feedback or dissemination of the data. A surveillance system for Hepatitis B was established in 1988 in order to improve prevention and control of transmission of this endemic disease. A disease register including data obtained mainly from notifications, laboratory reports and active case finding was established. This paper shows the findings from 1990 to 1993. The system shown cannot claim to be complete. However the findings suggest that some 14 clinically evident cases of Hepatitis B are confirmed each year. No rising trend has been seen. In anyone year a prevalence of 15.4 x 10-5 HBsAg positive results in persons who had previously not known that they were positive may be detected. Six month follow-up of these persons reveals that some 39 persons become chronic carriers each year. This has implications both for the targeted vaccination programme as well as for the individual’s chronic liver complications and treatment.peer-reviewe

Epidemiology of AIDS in Malta

The occurrence, frequency, distribution and determinants of HIV and AIDS are described for Maltese residents. Up to 30 June 1996, 38 notifications of AIDS were received by the Public Health Department (36 in males), 35 died. The overall mean survival between notification date and death was calculated using data for 28 reported cases as 216.71 days. Mean age at notification was 30.5 years (range: 2 to 48; median 31). Occurrence in males was highest for homosexuals/bisexuals (52.8%), followed by recipients of contaminated blood products (30.6 %) and heterosexual contact (5.6%). The two females acquired HIV through mother-to-child transmission (abroad) and heterosexual intercourse respectively. Mode of transmission was unrecognised in 7.9% of cases. Epidemiological data on AIDS cases usually reflects the situation of HIV transmission some twelve to fifteen years previously. Sero-surveillance studies are now indicated to clarify the actual prevalence of HIV infection.peer-reviewe

A cross-sectional survey of a dermatology outpatient service in Malta

A survey of the outpatient service provided by a consultant dermatologist at the national dermatology department in Malta was carried out. The aims of this study were to identify the main conditions being treated and to analyze management and referral practices. Possible implications for future training of primary care physicians were also investigated. The survey was carried out for one week every season over a 12-month period, giving a total study period of four weeks. Data was collected on a total of 662 patients (401 new patients and 261 follow-ups). The average waiting time for a routine clinic appointment for new cases was 4 weeks, but 18% of patients were seen within 48 hours of referral and 7% were seen within one week. Age-specific attendance rates were highest for females over 50 years and males over 60. Overall, the commonest conditions seen were chronic leg ulcers, psoriasis, skin infections and seborrhoeic keratoses. Skin biopsy was the most frequent investigation performed and topical treatment was the commonest form of therapy. Private general practitioners and government doctors based in health centres accounted for 51% and 29% of all referrals respectively. A diagnosis was offered in 65% of referral notes. Of these, 44% had a diagnosis matching that given by the dermatologist at the patient's first visit. Treatment was attempted prior to referral in 64% of patients with acne but in only 15% of patients with viral warts.peer-reviewe

Trends in sun exposure awareness and protection practices in Malta : 1999-2004

Rising skin cancer incidence rates have led to sun awareness campaigns in Malta since the early 1990s. The aim of this study is to assess the impact of these campaigns by analysing trends in sun exposure-related knowledge and behaviour amongst the Maltese people. A total of 559 Maltese pedestrians aged 16-50 years were interviewed in 1999. The same questionnaire was used to interview 304 pedestrians in 2004. More people admitted spending leisure time outdoors during peak sunshine hours in 2004 than in 1999 (85.9% vs 62.4%, p<0.001). There was a drop in people regularly wearing a hat during outdoor leisure activities from 32.4% to 18.4% (p<0.001), and from 37.5% to 9.3% (p<0.001) during outdoor work activities. Rates of regular sunscreen use remained constant at about 50% using it for outdoor leisure activities, but dropped from 25.0% to 9.3% for outdoor work (p=0.02). In 2004, 96.1% of participants having children aged less than 12 years stated that they regularly used sunscreen on their children (87.0% in 1999, p=0.01), while 66.2% said that their children regularly wore a hat (78.4% in 1999, p=0.05). More people were regarding a suntan as unhealthy in 2004 than in 1999 (62.8% versus 37.0%, p<0.001). The mass media remained the most important source of health information.peer-reviewe

Future Needs in Mast Cell Biology.

The pathophysiological roles of mast cells are still not fully understood, over 140 years since their description by Paul Ehrlich in 1878. Initial studies have attempted to identify distinct "subpopulations" of mast cells based on a relatively small number of biochemical characteristics. More recently, "subtypes" of mast cells have been described based on the analysis of transcriptomes of anatomically distinct mouse mast cell populations. Although mast cells can potently alter homeostasis, in certain circumstances, these cells can also contribute to the restoration of homeostasis. Both solid and hematologic tumors are associated with the accumulation of peritumoral and/or intratumoral mast cells, suggesting that these cells can help to promote and/or limit tumorigenesis. We suggest that at least two major subsets of mast cells, MC1 (meaning anti-tumorigenic) and MC2 (meaning pro-tumorigenic), and/or different mast cell mediators derived from otherwise similar cells, could play distinct or even opposite roles in tumorigenesis. Mast cells are also strategically located in the human myocardium, in atherosclerotic plaques, in close proximity to nerves and in the aortic valve. Recent studies have revealed evidence that cardiac mast cells can participate both in physiological and pathological processes in the heart. It seems likely that different subsets of mast cells, like those of cardiac macrophages, can exert distinct, even opposite, effects in different pathophysiological processes in the heart. In this chapter, we have commented on possible future needs of the ongoing efforts to identify the diverse functions of mast cells in health and disease

Non-averaged regularized formulations as an alternative to semi-analytical orbit propagation methods

This paper is concerned with the comparison of semi-analytical and non-averaged propagation methods for Earth satellite orbits. We analyse the total integration error for semi-analytical methods and propose a novel decomposition into dynamical, model truncation, short-periodic, and numerical error components. The first three are attributable to distinct approximations required by the method of averaging, which fundamentally limit the attainable accuracy. In contrast, numerical error, the only component present in non-averaged methods, can be significantly mitigated by employing adaptive numerical algorithms and regularized formulations of the equations of motion. We present a collection of non-averaged methods based on the integration of existing regularized formulations of the equations of motion through an adaptive solver. We implemented the collection in the orbit propagation code THALASSA, which we make publicly available, and we compared the non-averaged methods to the semi-analytical method implemented in the orbit propagation tool STELA through numerical tests involving long-term propagations (on the order of decades) of LEO, GTO, and high-altitude HEO orbits. For the test cases considered, regularized non-averaged methods were found to be up to two times slower than semi-analytical for the LEO orbit, to have comparable speed for the GTO, and to be ten times as fast for the HEO (for the same accuracy). We show for the first time that efficient implementations of non-averaged regularized formulations of the equations of motion, and especially of non-singular element methods, are attractive candidates for the long-term study of high-altitude and highly elliptical Earth satellite orbits.Comment: 33 pages, 10 figures, 7 tables. Part of the CMDA Topical Collection on "50 years of Celestial Mechanics and Dynamical Astronomy". Comments and feedback are encourage

The 10 Tesla muSR instrument: detector solutions

Solutions to the detector system of the High-Field muSR instrument at the Paul Scherrer Institut (PSI) in Switzerland are presented. The strict technical requirements are fulfilled through the application of Geiger-mode Avalanche Photodiodes.Comment: 6 pages, 4 figure