An interesting case of pacemaker endocarditis

Netherlands Heart Journal -     

An interesting case of defective HLA phenotype

In a 27 years old man whose parents had HLA phenotypes A 9/B 7, Bw 16 and Al/B 17, B 18 only HLA-B 18 could be reliably identified in lymphocytes by means of microlymphocytotoxic tests. It is probable that HLA-Bw 16 was also present in the lymphocytes of this test person. Even by applying the neutralisation test, the HLA antigens A 1 and a 9 could not be detected in the test person's serum. The cause for the existence of the defective HLA phenotype is discussed.     

An improved colloidal iron stain for glomerular sialoproteins

Summary The thick sialoglycoprotein coat of the glomerular epithelial cells is a part of the glomerular filtration barrier. It can be demonstrated in paraffin histology by means of the colloidal iron procedure. We have studied the special requirements of tissue processing to obtain reproducible results by this staining method. The requirements include proper fixation, avoiding heat during sectioning and ample rehydration. We have further tested a colloidal iron-PAS procedure for simultaneous demonstration of the glomerular epithelial coat and the basement membrane.     

An improved colloidal iron stain for glomerular sialoproteins

The thick sialoglycoprotein coat of the glomerular epithelial cells is a part of the glomerular filtration barrier. It can be demonstrated in paraffin histoslogy by means of the colloidal iron procedure. We have studied the special requirements of tissue processing to obtain reproducible results by this staining method. The requirements include proper fixation, avoiding heat during sectioning and ample rehydration. We have further tested a colloidal iron-PAS procedure for simultaneous demonstration of the glomerular epithelial coat and the basement membrane.     

An interesting diagnosis for a presacral mass: case report

A presacral mass can present a diagnostic dilemma for the surgical oncologist. Differential diagnoses include congenital causes such as teratoma or chordoma, neurological causes such as neurilemoma or neurofibroma or other malignancies such as lymphoma or sarcoma. Diagnosis usually requires imaging such as CT and MRI and tissue biopsy. We present an unusual cause of a presacral mass being extramedullary haematopoiesis, found incidentally in a 71 year old female. Extramedullary haematopoiesis is defined as the production of myeloid and erythroid elements outside of the bone-marrow. This diagnosis is extremely rare in the presacral area especially in a patient with no haematological abnormalities. A review of the literature is presented.     

An interesting rock from Krapina

Symbolic items are seldom associated with Neandertals and, when they are, many paleoanthropologists consider them to be Neandertal imitations from modern Homo sapiens. At the Croatian site of Krapina dated to MIS 5e or about 130,000 years ago, among many items, a split limestone rock was excavated by Dragutin Gorjanović-Kramberger between 1899-1905. This brownish rock reveals many dark dendritic forms in cross- and longitudinal section. Of more than 1000 lithic items at Krapina, none resemble this specimen and we propose it was collected and not further processed by the Neandertals because of its aesthetic attributes. Along with other examples from sites in western and central Europe and the recent discovery of eight modified white-tailed eagle talons from Krapina, this unique item suggests that Neandertals were capable, on their own, of incorporating symbolic objects into their culture.     

An innately interesting decade of research in immunology

"Nature has provided, in the white corpuscles as you call them-in the phagocytes as we call them-a natural means of devouring and destroying all disease germs. There is at bottom only one genuinely scientific treatment for all diseases, and that is to stimulate the phagocytes." So opined B.B. in G.B. Shaw's The Doctor's Dilemma in a dramatic restatement of a key portion of Ilya Metchnikoff's Nobel Prize address: "Whenever the organism enjoys immunity, the introduction of infectious microbes is followed by the accumulation of mobile cells, of white corpuscles of the blood in particular which absorb the microbes and destroy them. The white corpuscles and the other cells capable of doing this have been designated 'phagocytes,' (i.e., devouring cells) and the whole function that ensures immunity has been given the name of 'phagocytosis'". Based on these insights into the foundation of resistance to infectious disease, Metchnikoff was awarded the 1908 Nobel Prize in Physiology or Medicine together with Paul Ehrlich (Fig. 1). Although both were cited for discoveries in immunity, the contributions of the two men seem worlds apart. Ehrlich's studies did not deal with generic responses to infection, but rather with the highly specific nature of antibodies and their relationship to the cells producing them: "As the cell receptor is obviously preformed, and the artificially produced antitoxin only the consequence, i.e. secondary, one can hardly fail to assume that the antitoxin is nothing else but discharged components of the cell, namely receptors discharged in excess". But biological systems are just that-systems-and the parts need to work together. And so we arrive, a century later, at an appreciation for just how intimately related these two seemingly disparate aspects of host defense really are.     

Tetrodecamycin: An unusual and interesting tetronate antibiotic

The tetrodecamycins are a group of secondary metabolites that are characterized by the presence of a tetronate ring in their structure. Originally discovered for their antibiotic activity against Photobacterium damselae ssp. piscicida, the causative agent of pseudotuberculosis in fish, this family of molecules has also been shown to have potent antibiotic activity against methicillin-resistant Staphylococcus aureus. Due to their small size and highly cyclized nature, they represent an unusual member of the much larger group of bioactive molecules called the tetronates. Herein, we review what is known about the mechanism of action of these molecules and also present a hypothesis for their biosynthesis. A deeper understanding of the tetrodecamycins will provide a more holistic view of the tetronate-family, provide new chemical probes of bacterial biology, and may provide therapeutic lead molecules.     

趣味实验——月季花水插生根

月季花插试验利用水生诱变技术,使月季插穗产生水生根系,以适应水生环境,具有趣味性和实用性,介绍了月季花水插生根原理,阐述了试验的方法与步骤并采用追踪拍摄的手法记录月季花水插生根过程,最后指出本实验的意义,旨在激发中学生的学习热情和求知欲,培养其各方面的能力。