Importance of platelet functions in Alzheimer's disease

The function of platelets of patients with Alzheimer's disease has been characterized. The shape of platelets is more spherical and the initial rate of platelet aggregation caused by different agonists measured in plasma is faster in the case of Alzheimer's disease and senile dementia of the Alzheimer-type than that of other demented patients: multi infarct dementia and probable vascular dementia. Although fast aggregation is characteristic of activated platelets but the Alzheimer platelets are not hypersensitive. The activation of Alzheimer platelets makes the velocity of ADP induced aggregation slower and it is different than the behaviour of normal activated platelets. The shape-associated parameter and the initial rate of 50 microM ADP-induced aggregation of platelets non-activated and activated by cytochrome C are recommended for establishing the diagnosis of Alzheimer's disease and senile dementia of the Alzheimer-type. The evaluation of these parameters has been discussed. The cytochrome C may be useful to normalize the function of Alzheimer platelets in plasma, not only in vitro.     

Surgical management of villous and tubulovillous adenomas of the rectum]

One hundred four cases of middle and low rectal villous and tubulovillous adenomas have been operated on with transanal polypectomy (8), transanal endoscopic microsurgery--TEM (80), anterior rectum resection with double stapled straight sigmoideorectosomy (7), and deep rectum resection, bi-directional mucosectomy and hand sutured straight sigmoideoanostomy (9). The option of the authors to remove the tumours in 5 cm to the dentate line are the transanal polypectomy or transanal mucosectomy corresponding to their size. The transanal endoscopic microsurgical technic is recommended to manage the polyps smaller than 4 to 5 cm in the middle rectum. The best radicallity in removal of the circular, extended villous adenomas could be achieved with deep rectum resection, bi-directional mucosectomy and transanal straight, hand sewn sigmoideoanostomy.     

Abdominal actinomycosis presenting as a malignant tumor--report of a case and review of the literature

Actinomyces israelii is a normal inhabitant in the gastrointestinal tract of humans, it rarely causes disease. Abdominal involvement occurs in only 20 percent of all cases and can mimic malignant diseases, tuberculosis and inflammatory bowel disease. A case of a 36 years old female patient with abdominal actinomycosis and review of the literature is reported. Symptoms was presented as an acute abdomen associated with painful epigastric and left subcostal mass. The pathologic process infiltrated the retroperitoneal space simulated sarcoma or lymphoma. Diagnosis was established only at the second laparotomy, when histologic examination of the removed lymph node disclosed actinomycosis. The patient is completely free of symptoms 6 month after the second operation.     

Relationship between clinical and radiological diagnostic criteria for Alzheimer's disease and the extent of neuropathology as reflected by 'stages': a prospective study

The distribution of pathology related to Alzheimer's disease (AD) is not uniform throughout the brain. Sites which have a predilection for the development of Alzheimer-type pathology are the limbic regions and neocortical association areas. The changes in these areas of the brain develop gradually, following a well-determined sequence that allows a pathological staging of the disease process. According to the staging hypothesis, the first pathological alterations develop in the transentorhinal and entorhinal regions. The neurofibrillary pathology then spreads into the hippocampus, but not until the final stages does it affect the neocortex. In this study we analyse the relationship between the pathological stages of AD, according ot the staging hypothesis, and the clinical diagnosis in a prospectively assessed patient group. Prediction of any given pathological stage from the clinical diagnosis was found to be poor. This may be partly due to the fact that additional pathologies can alter the clinical picture and severity of dementia in patients who are only in the initial stages of AD. Nevertheless, the NINCDS-ADRDA clinical criteria had a high sensitivity for detection of AD-related pathology: the 'probable AD' category included 22/38 (57.9%) of those in the late isocortical stage, while the 'possible AD' category included 19/23 (82.6%) of those in the limbic stage. Using proposed neuro-imaging protocols for improved identification of patients with AD-related pathology, we largely identified subjects in whom the extent of pathology had spread to the neocortex.     

PEG-Hemoglobin as a resuscitation solution in the treatment of hypovolemic shock in the anesthetized rat

This study was designed to determine the advantages of using the hemoglobin-based oxygen carrier, polyethylene glycol conjugated bovine hemoglobin (PEG-Hb), as an additive to Ringer's lactate solution (RLS) for the treatment of acute hemorrhage in anesthetized female rats. Different compositions of PEG-Hb and RLS were administered intravenously in a paradigm that provided 30 ml/kg of resuscitation fluid following an episode of 15 min of hypotension. Hypotension was achieved by the removal of blood (1 ml/min) from the femoral vein until the mean arterial pressure was lowered to or below 50 mmHg and subsequently maintained until resuscitation. Short-term cardiovascular assessment showed that resuscitation fluids containing PEG-Hb resulted in higher mean arterial pressure, aortic blood flow, renal blood flow, and less dramatic shifts in arterial base excess and respiratory blood gases than plain RLS. The long-term survival experiment showed lower lactate dehydrogenase, alkaline phosphatase, and serum glutamic pyruvic transaminase levels in most groups resuscitated with solutions containing PEG-Hb, but no differences in survival (100%) were observed. The data suggest that the addition of PEG-Hb to RLS improves its resuscitative effects. Specifically, a solution of 50% RLS:50% PEG-Hb appeared to have the most favorable cardiovascular and metabolic effects in this anesthetized rat hypovolemic shock resuscitation model. Presumably, the improved effects seen with the addition of PEG-Hb were due to its innate plasma expansion and oxygen-delivery capabilities.     

A note on the early history of renal transplantation: Emerich (Imre) Ullmann

In January 1902 at the Vienna Medical Society Meeting, the surgeon Emerich Ullmann reported the first case of renal autotransplantation performed in the neck of a dog. In the same year, he presented the first xenotransplantation of the kidney (a goat with a dog's kidney). These publications immediately had a great impact on the medical word. After his failed attempt to transplant a pig's kidney into a young uraemic woman he stopped his research in this field in order to devote himself to other lines of surgical research. However, his idea survived him, because, nowadays, nearly 100 years later, pigs appear to be the most suitable donors for human renal xenotransplantation. Ullmann was born in Pécs, Hungary, on February 23, 1861. After a distinguished undergraduate career in 1878 his father (being also a medical doctor) sent him to study medicine at the world-famous Vienna Medical School. He graduated in 1884 and was immediately invited to the Surgical Department where Billroth worked. Next year, because of his interest in bacteriology he visited Pasteur in Paris and successfully volunteered to serve as a healthy subject to prove the effectiveness of Pasteur's antisera against rabies. Although Ullmann did not succeed in doing a human transplantation he gave birth to the era of the organ transplantation, stimulated vascular surgery and the development of transplantation immunology.     

The role of diagnostic laparoscopy in staging of pancreatic cancers

Authors report elective diagnostic laparoscopy, and the role of this method in evaluating operability of pancreatic cancer. At their department 11 diagnostic laparoscopic procedures of pancreatic cancer were performed during the last 5 years. In 3 cases tumor proved to be resectable despite preoperative imaging results of unresectable condition. On the basis of international literature authors give brief summary of indications, cost and benefit of diagnostic laparoscopy, and its place in the diagnostic algorythm of pancreatic cancer.     

Photoreceptor cells with unusual functional properties on the ventral nerve of Limulus

Normal photoreceptor cells on the ventral nerve of Limulus respond to a moderately intense flash with a large receptor potential or current. Occasionally, cells are found in which the same flash evokes only a small receptor potential or current. Our investigations reveal physiological reasons for the poor light sensitivity in these "unusual cells." In unusual cells prolonged illumination with intense light evokes a step-like inward current with an amplitude of some nanoamperes, but without a large transient peak. The current appears to be summed up of single photon responses with amplitudes smaller than about 50 pA. Their time course is similar to that of small single photon responses forming the so-called macroscopic C1 component in normal cells. The macroscopic current evoked by an intense flash has slow activation and deactivation kinetics and reaches a saturated amplitude of about 4-5 nanoamperes. The light-intensity dependence of the current evoked by flashes or by prolonged illumination has a slope of about 1 in log-log plots. The decay kinetics of the current is similar to that of the C1 component measured in normal cells after the block of the C2 component. Occasionally, the step-like current is superposed by large standard bumps. These bumps are blocked by the Ca2+-ATPase inhibitor cyclopiazonic acid, while the sustained inward current persists. We conclude that in unusual cells the light-activated current is identical to the C1 component of normal cells. The phospholipase C pathway that in normal cells presumably gives rise to the C2 component functions only with a low efficiency in unusual cells.     

The eyes of transforming growth factor-sZ1 (TGF-sZ1) transgenic mice Morphology and the development of endotoxin-induced uveitis

Transforming growth factor-beta (TGFsZ) is a potent regulator of cellular growth and immune function. The authors studied ocular histology and endotoxin-induced uveitis in a TGF-sZ(1) transgenic (Tg) murine model. TGF-sZ(1) Tg mice were generated by micro injecting a gene constructed by fusing the mouse albumin enhancer/promoter and porcine TGF-sZ(1) cDNA. The eyes of Tg mice from two to 14 weeks of age were studied histologically. Tg mice, two to five weeks of age exhibited mild fragmentation of the lens fibers and retinal edema. No pathology was found from six to ten weeks of age, however, a progressive increased frequency of cataract was observed from 11 to 14 weeks of age. Plasma TGF-sZ(1) levels were much higher in Tg mice than age-matched wild type control littermates (wt). Endotoxin-induced uveitis (EIU) in six-to eight-week-old Tg and wt mice was induced by footpad injection of lipopolysaccharide (LPS). Mice were euthanized 24 hr after LPS injection, the eyes were collected for histology and serum assayed for IL-6 and TGF-sZ(1). There was a decrease in the mean numbers of infiltrating cells in Tg mice compared to wt mice. Serum IL-6 and TGF-sZ(1) were much higher in Tg mice. The authors concluded that expression of the TGF-sZ(1) transgene in the eyes may have effect on lens growth. Overexpression of TGF-sZ(1) results in little or no effect on the development of EIU.     

Synaptic connections linking cones and horizontal cells in the retina of the pikeperch (Stizostedion vitreum)

Cones and horizontal cells of the pikeperch retina were studied with morphological and physiological techniques. Gap junctions were observed between cone pedicles and basal processes emitted by neighboring cones. Intracellular recordings showed that the light-evoked hyperpolarizing cone response was enhanced by light falling upon neighboring receptors within a radius of 50 microns. We suggest that the network of gap junctions between cones mediates the summative lateral interaction described. Three sub-classes of horizontal cells (H1, H2, H3) send dendrites to cones; H1 and H2 cells appear to contact twin cones, exclusively or preferentially, whereas H3 cells appear to synapse only with single cones. Horizontal cells of the same sub-class are joined by gap junctions between dendrites or at the lateral faces of perikarya. These unions extend over several micron 2 and as seen in transmission electron microscopy consist of patches of close apposition alternating with areas of membrane separation, folding and occasional zonulae adherents. Freeze-fracture profiles of horizontal gap junctions show localized areas of dense particle aggregation on the P-face and pits on the E-face flanked by regions of unspecialized membrane. These morphological findings provide support for the known spatial and color-coding properties of pikeperch horizontal cells.