New and unusual O alleles at the ABO locus are implicated in unexpected blood group phenotypes

BACKGROUND: In the ABO blood group system mutations in the A gene may lead to weak A subgroups owing to a dysfunctional 3-alpha-N-acetylgalactosaminyltransferase. STUDY DESIGN AND METHODS: Blood and DNA were investigated to correlate weak A phenotypes with genotype, and an overrepresentation of the infrequent O2 allele was observed. Consequently, 57 available O2 alleles were examined in detail. RESULTS: Two new O2 alleles were identified having mutations resulting in Gly229Asp with or without Arg217Cys. A recently described O2 variant (488C>T; Thr163Met) was also found. Surprisingly, both the original and the variant O2 alleles were associated with either O or Aweak phenotypes. Three novel O alleles surfaced in six other samples with suspected A subgroups. These were A1-like alleles having nonsense mutations causing premature truncation at codons 56, 107, or 181. A second example of the rare O3 allele was also identified. A newly described O1 allele having 768C>A was found to be the third most frequent O allele among Swedish donors. Of the five novel O alleles, three were incorrectly interpreted as A1 following routine ABO genotyping. CONCLUSION: Apparent O alleles lacking 261delG may cause weak A expression on red blood cells and/or inhibit anti-A production. A hypothesis that exchange of genetic material between principally dissimilar O alleles during mitosis ("autologous chimerism") restores glycosyltransferase activity in some cells would explain this interesting phenomenon.     

Brown tumor of the femur associated with double parathyroid adenomas

Severe parathyroid bone disease is a rare clinical presentation of primary hyperparathyroidism. Double parathyroid adenomas are even more rare cause of primary hyperparathyroidism. The authors present a case of double parathyroid adenomas in a 48-year-old man, who presented with painful left lower limb swelling, which was slowly growing in size in the last 20 years. Magnetic resonance imaging revealed a cystic bony lesion and coincidentally, a urinary bladder calculus. Biopsy of the mass revealed giant cell lesion. Laboratory investigations showed hypercalcemia and hypophosphatemia with elevated parathyroid hormone level. A computerized tomography scan of the neck delineated an adenoma of the left superior parathyroid gland, which was surgically removed. The left inferior parathyroid was also enlarged and was removed. Histological diagnosis confirmed double parathyroid adenomas. The rarity and the interesting clinical presentation of such association are discussed.     

Symptoms and acute pesticide intoxication among agricultural workers in Lebanon

Pesticides are known for their toxicity and are still widely used, especially in agriculture. Increasing attention is being focused on the health effects affecting humans occupationally exposed to pesticides, particularly agricultural workers. The objective of this study was to assess the association between occupational exposure to pesticides with recurrent symptoms and acute intoxications, in comparison with other workers in Lebanon. A cross-sectional study was undertaken, where a standardized questionnaire was administered to 89 exposed and 88 non exposed workers. Subjects exposed to pesticides reported more upper respiratory tract infections (PR = 9.39 ; p < 10(-4)), anorexia (PR = 3.63 ; p = 0.03), epistaxis (PR = 2.97; p = 0.02), immunoallergic (PR = 1.58 ; p = 0.01) and gastrointestinal (PR = 2.13 ; p < 10(-4)) symptoms. Acute pesticide intoxications requiring hospitalization were also more common (PR = 4.26; p = 0.01). Adjustment over potential confounding did not change the results, except for the appearance of an association of central (PR = 1.50 ; p = 0.04) and autonomic nervous systems symptoms (PR = 3.92 ; p = 0.01) with agricultural work in Mount Lebanon. Our results suggest that agricultural workers have a higher prevalence of multiple symptoms, which may be due to subacute intoxications by pesticides that did not need hospitalization. In addition, these workers have a higher risk of having an acute intoxication due to pesticides, exposing them to life-threatening situations.     

What do we mean by Internet access? A framework for health researchers

Much is written about Internet access, Web access, Web site accessibility, and access to online health information. The term access has, however, a variety of meanings to authors in different contexts when applied to the Internet, the Web, and interactive health communication. We have summarized those varied uses and definitions and consolidated them into a framework that defines Internet and Web access issues for health researchers. We group issues into two categories: connectivity and human interface. Our focus is to conceptualize access as a multicomponent issue that can either reduce or enhance the public health utility of electronic communications.     

Emotional adjustment to stroke: a group therapeutic approach

Many people find it difficult to come to terms with having had a stroke and the resulting physical disability. This article reports on the setting up and running of psychological therapeutic groups to provide emotional and psychological support to patients about six months after their stroke. A flexible approach has allowed different groups to take different approaches to dealing with individuals' situations. Initial evaluations suggested that the groups help patients in the emotional processing of their experience of stroke and in promoting psychological adjustment to their changed circumstances. Group members have identified other gaps in service provision, such as a need for stroke education, and these gaps have been addressed.     

IgH PCR of zinc formalin-fixed,paraffin-embedded non-lymphomatous gastric samples produces artifactual "clonal" bands not observed in paired tissues unexposed to zinc formalin

Helicobacter pylori (HP) causes dense gastritis that can be difficult to distinguish morphologically from MALT-type lymphoma (ML). Immunoglobulin heavy chain (IgH) gene analysis by polymerase chain reaction (PCR) is often used to resolve diagnosis. However, monoclonal bands have been reported in nonmalignant cases of gastritis. Retrospectively, 16 gastric ML with both formalin-fixed, paraffin-embedded (FF-PE) and ethanol-fixed samples (EF), and 9 cases of FF-PE HP-gastritis were analyzed by IgH PCR to document the presence of non-reproducible bands in HP-gastritis, but not ML samples. In duplicate analyses, 12 of 16 ML yielded identical monoclonal bands in FF-PE and EF samples whereas 3 of 9 FF-PE gastritis cases yielded different-sized (ie, non-reproducible) “clonal” bands. Sequencing of two PCR products from a gastritis case confirmed IgH gene sequences. To investigate whether FF-PE had a direct effect on producing these non-reproducible bands, 7 gastrectomy samples were prospectively divided into EF and FF-PE halves for IgH PCR. All 7 samples demonstrated polyclonal smears in EF portions while 4 of 7 FF-PE portions yielded either multiple distinct bands or non-reproducible bands. In conclusion, IgH PCR of FF-PE tissue can create artifactual “clonal” bands, which are the appropriate product size, contain IgH sequences, and, if not performed in duplicate, may confuse interpretation of B-cell clonality.     

Superior oblique myokymia secondary to neurovascular compression

In a patient with superior oblique myokymia, a contact is visualised between the right trochlear nerve and a vascular structure by high resolution thin slices magnetic resonance images coupled to angio-MR. A similar contact is not visualised on the left side. This suggests that the neuro-vascular contact is the cause of this superior oblique myokymia and offers the possibility of neuro-surgical decompression if necessary.