New insight into genetic disease : the role of trinucleotide repeat expansions

The development of genetics in the last few decades is replete with surprise phenomena and new findings. One such phenomenon is the trinucleotide repeat expansion, a new type of mutation first discovered in 1991. These genetic diseases usually appear late in life and show the unusual phenomenon of anticipation in which the disease appears earlier and increases in severity in subsequent generations. In the present age of molecular genetics all physicians must be informed and educated about the implications of genetic diseases. Equally, there must be appropriate facilities for genetic testing and counselling and it is the responsibility of health authorities to ensure that such facilities are available and adequate.peer-reviewe

A survey of chromosome anomalies in Malta

433 individuals referred for chromosome analysis between 1983 and 1987 were included in the survey. Among individuals with dysmorphic features or congenital anomalies 42% of babies referred in the neonatal period and 12 to 30% of individuals in older age groups had a chromosome abnormality. Chromosome abnormalities were also found in 10 or 11% of boys or girls with problems of pubertal development, in 14% of azoospermic or severely oligospermic men, in 8.3% of couples with repeated foetal loss and in 5% of couples with malformed children. Whereas most cases of autosomal aneuploidies were diagnosed, a large proportion of sex chromosome anomalies, particularly in males, remained undetected presumably because of under-referral in the pubertal period. The prevalence of chromosome anomalies in Malta was 2.20 per 1,000 births between 1984 and 1987. The incidence of Down Syndrome showed great annual fluctuation with a mean of 1.88 per 1,000 births of which 61% occurred in mothers over 35 years of age. The lowest occurrence risk for trisomy 21 appears to be in the 25 to 34 years maternal age group.peer-reviewe

Functional anatomy of olfactory sense organs

The olfactory organ is the most primitive of the organs of special sense and the one with the simplest structural organization, and yet it has defied a clear exposition of the way in which it perceives and distinguishes between different odours. The olfactory organ also has a simple structural organization consisting of receptor cells surrounded by supporting cells and overlying a layer of basal cells. Particular areas in relation to the functional anatomy of this organ, such as the fine structure of the olfactory mucosa, the surface fluid and the olfactory pigment are discussed. Perhaps the greatest paradox in olfactory research is that we still do not know the nature of the essential stimulus that constitutes a smell.peer-reviewe

A survey of congenital anomalies in Malta

This study comprises a register of all cases of congenital anomalies recorded at the time of birth during the nine year period from 1983 to 1991. The occurrence of individual anomalies was analyzed in relation to the maternal age, gestational age, birth weight, twinning, still births, neonatal deaths and geographical distribution. Not only does the study provide accurate prevalence and incidence figures which are of importance to public health and the community as a whole, but it also provides a source of ascertainment of hereditary anomalies with their inherent recurrence risks which are of importance to individuals for genetic counselling. The validity of the register depends on the completeness of ascertainment and the use of a pathological international classification which demands diagnostic precision especially in cases of multiple congenital anomaly syndromes. The prevalence figures for individual anomalies are compared with those of other countries. The Maltese register forms part of the EUROCAT project (European Register of Congenital Anomalies and Twins), a concerted action project organised by the European Community for the international surveillance of congenital anomalies with the aim of detecting temporal and spacial clustering and the identification of responsible teratogens.peer-reviewe

Screening for genetic diseases : what are the moral constraints?

Now that the Human Genome Project (HGP) is an ongoing and rapidly progressing reality, and human genetic engineering is expected to become standard procedure, the inevitable question is how these procedures will be applied. The inevitable and much debated answer is eugenics. It is often looked upon as positive eugenics, directed perhaps, towards achieving human beings endowed with optimal characteristics of physical strength and beauty, intellectual genius and longevity. There is of course the immense and probably insoluble problem of determining which human characteristics, among nature's rich and superb diversity, can be improved and what constitutes the hypothetical physical and intellectual excellence that one might envisage and enhance. There is no doubt that the most important applications of powerful genetic technology have been in the field of genetic diagnosis, and treatment using genetic engineering is well on the way to new applications. These are the tremendous contributions of medical genetics to the control of human disease. There is no doubt that this ideal leads the list of eugenic priorities. Genetic testing is only one small but essential step toward achieving these priorities.peer-reviewe

Design of a 2 DOFs Mini Hollow Joint Actuated with SMA Wires

Shape memory alloys (SMAs) are smart materials used in robotics because of its light weight and high force-to-weight ratio. The low energy efficiency, up to 5%, has limited their use for large actuators. However, they have shown advantages in the design of mini-robots because of the limited volume required for the actuation system. The present study reports the design and construction of a mini compliant joint (MCJ) with a 2 degrees of freedom (DOFs) intersecting axis. The MCJ prototype has a 20 mm external diameter surrounding a cavity of 8 mm, weighs 2 g, is 20 mm high and can perform an angle rotation of 30 ∘ in less than 260 ms. It uses SMA NiTi wires in antagonistic configuration and springs to reduce the energy consumption and minimise heat production. The design methods and experimental results of the manufactured prototype are reported and discussed

In vitro immunomodulatory activity of various extracts of Maltese plants from the Asteraceae family

Various extracts of ten plants from the Asteraceae family were studied for their effects of on human peripheral T-lymphocytes in vitro. Five solvent systems were used to extract constituents from these plants. Phytochemical identification of the most prevalent phytochemical classes was carried out, followed by screening for pharmacological activity using the Brine Shrimp Lethality test (BST). One BST-negative and five BST-positive extracts were tested on human lymphocytes. Marked effects were observed in treated lymphocytes with all six extracts. However only two extracts caused lymphocyte activation and pronounced blastogenesis similar to that of phytohaemagglutinin (PHA). The results obtained indicate that in particular the petroleum ether extract of Calendula arvensis is relatively non-toxic to peripheral lymphocytes suggesting its potential use as an immune booster.peer-reviewe

Results of biliary operations without operative cholangiography

Paper read at the Meeting of the Moynihan Chirurgical Club held in Malta in May 1969. In St. Lukes Hospital Malta, for a number of reasons, we do not use routine operative cholangiography. In this review an attempt is made to analyse the results of biliary operations without its use. The records of patients who underwent biliary operations for non-malignant conditions in the five-year period between 1963 and 1967 are here reviewed. The total number of patients was 229. Of these, 18 have been excluded because their records could not be traced. This leaves for consideration 211 patients on whom a total of 214 operations were performed. The results of biliary operations, without the use of operative cholangiography are analysed. The low incidence (1.2%) of residual stones following cholecystectomy only does not justify the routine use of operative cholangiography. The high incidence (9.1% to 13.6%) of residual stones after choledochotomy should lead to the adoption of post-exploratory operative cholangiography in those cases where the ducts are explored. Additionally, the exploration rate is also compared to similar studies carried out overseas.peer-reviewe