Morphologic analysis of rat retinocollicular neuron terminals containing monoamine oxidase

The retino-collicular neuron terminals containing type A monoamine oxidase (MAO-A) in the stratum griseum superficiale of the rat superior colliculus were analyzed to provide a morphologic basis for the physiologic role of these neurons in the visual pathway. A computer-assisted, three-dimensional re-construction of the terminal complex associated with the MAO-A-positive terminals was performed. MAO-A-positive terminals originated in the retina and terminated in the stratum griseum superficiale. This was confirmed by tract tracing and enucleation experiments. The terminals were densely grouped in clusters of irregularly shaped swellings. Electron microscopy revealed that the MAO-A-positive terminals were located in a glomerulus-like structure. In this terminal complex, a significant proportion of the axonal profiles (42.96%) synapsed with the MAO-A-positive terminals. Most of the profiles (24.16%) resembled presynaptic dendrites, which represent intermediate elements between the retinal terminals and conventional dendrites. Unlike the glomerulus in the dorsal lateral geniculate body, the MAO-A-positive terminal swellings were not located in the central part of the terminal complex. The terminals had an irregular shape and were located in the complex. The terminal complex was partially ensheathed by glial processes. Furthermore, the membrane surfaces exhibiting synaptic specializations were very small compared with the total surface of the terminal swellings. The membrane length of the synaptic specialization was 5.38% of the total perimeter of the MAO-A-positive terminals.     

Evaluation and selection of candidates for renal transplantation at the Clinical Hospital Center in Rijeka

On December 31, 2001, 2486 patients with terminal renal failure received dialysis treatment in Croatia. Only one third of the patients are registered on the national waiting list for cadaveric kidney transplant. In most of the others, transplantation is impossible because of comorbidity. This is mainly due to the steadily growing age of the dialytic population and therefore a higher incidence of cardiovascular disease and diabetes. Still, evaluation of the potential recipients of cadaveric kidney transplant, registered on the waiting list, often reveals contraindications for transplantation. The aim of this study was to determine the incidence and type of contraindications in transplant candidates, found during immediate preoperative evaluation. Analysis of these data should help in determining how contraindications can be early detected and prevented. Before registering onto the national waiting list transplant candidates need to be thoroughly investigated including detailed history, physical examination, routine diagnostic procedures and additional examinations, if needed, to exclude or evaluate the possibly existing contraindications for transplantation. During the period from January 1997 until June 2002, 145 potential recipients from the national waiting list were referred to the Rijeka University Hospital Center and evaluated for kidney transplantation. Eighty-eight patients underwent transplantation. Preoperative evaluation revealed contraindications for transplantation in 52 (35.9%) candidates. Twenty-two (15.2%) patients had a positive cross-match with donor lymphocytes, 6 (4.1%) patients refused transplantation, and in 24 (16.6%) patients serious comorbidity was the reason for not being accepted for transplantation and for their withdrawal from the national waiting list. Comorbidity was mainly due to cardiovascular disease (12 patients--8.3%) and infection (8 patients--5.5%). These data show a high incidence of contraindications found during the immediate preoperative evaluation of potential kidney recipients. It was the case in more than one third of patients. During the evaluation of potential candidates for kidney transplantation special attention should be addressed to the presence of cardiovascular morbidity and infection. Peripheral vascular occlusive disease, cardiac status and/or cerebrovascular disease should be evaluated. Measures used to treat or reduce the development of complications include an optimal control of blood pressure, serum phosphate, hyperparathyroidism, dyslipidemia, and renal anemia. The sites of infection must be treated and eradicated, because immunosuppressive treatment is a threat to the transplant recipient's life. The second most common cause of refusal of potential candidates was a positive cross-match with donor lymphocytes. Sensitization to human leukocyte antigens can be prevented by the avoiding of blood transfusions and use of erythopoietin in treating renal anemia. To minimize the morbidity and mortality, the potential kidney recipients should undergo rigorous selection and thorough evaluation before including them into the waiting list for kidney transplantation. Afterwards, regular examinations are obligatory to reveal contraindications, proceed to medical interventions and treat concomitant diseases in time, which can influence the patient's survival. In case that contraindications for transplantation arise, the patient must be temporarily or definitely removed from the waiting list.     

Multicenter clinical trial for evaluating methylprednisolone pulse treatment of idiopathic optic neuritis in Japan. Optic Neuritis Treatment Trial Multicenter Cooperative Research Group (ONMRG).

BACKGROUND: A randomized, controlled clinical trial was conducted in 1991 to compare an intravenous megadose of methylprednisolone with a control drug (mecobalamin) for treating acute idiopathic optic neuritis. CASES: Sixty-six cases from 22 clinical centers throughout Japan were examined to evaluate the treatment on visual function parameters, such as visual acuity, visual field, color vision, contrast sensitivity, and critical flicker frequency. OBSERVATIONS: The methylprednisolone pulse treatment group showed faster recovery of visual function, particularly the visual acuity at 1 week (P<.05), Humphrey field analyzer mean deviation at 3 weeks (P<.05), and color vision at 1 week (P<.05). Recovery of contrast sensitivity at several different spatial frequencies was significant in the pulse treatment group at 1 (P<.01), 2 (P<.05), and 4 weeks (P<.05) after the start of treatment. Visual function test results at 12 weeks and 1 year were essentially the same in the two treatment groups. Side effects appeared more frequently in the pulse treatment group than in the control (P<.05). CONCLUSIONS: Pulse treatment does not appear effective for idiopathic optic neuritis even though visual function in the pulse treatment group of this trial recovered more quickly during the initial phase compared to the controls. More effective and specific treatment should be established for optic neuritis.     

No evidence of association of methylenetetrahydrofolate reductase polymorphism with occurrence of second neoplasms after treatment of childhood leukemia

Methylenetetrahydrofolate reductase (MTHFR) polymorphisms have been associated not only with the risk for acute lymphoblastic leukemia (ALL) in adults and children, but also with increased methotrexate toxicity. The present study aimed to investigate whether MTHFR polymorphisms modify the risk for development of secondary malignancies in children treated for ALL with protocols that included high-dose methotrexate. MTHFR genotypes were determined in DNA samples isolated from archived bone marrow smears of 15 patients with a second malignancy and a matched control group of 30 patients who did not developed a second malignancy after the treatment for ALL. The frequencies of MTHFR C677T and A1298C genotypes in all patients were: C677T: CC 40%, CT 46.7% and TT 13.3% and A1298C: AA 46.7%, AC 44.4% and CC 8.9%. The relative risk for second malignancy was not significantly increased in ALL patients having at least one polymorphic C667T [odds ratio (OR) 1.51; 95% confidence interval (CI) 0.43 - 5.31] or one polymorphic A1298C allele (OR 1; 95% CI 0.29 - 3.46). Our study suggests that MTHFR polymorphisms are not associated with increased risk of second cancer in children treated with high-dose methotrexate.     

Virome of Ixodes ricinus,Dermacentor reticulatus,and Haemaphysalis concinna Ticks from Croatia

Tick-borne diseases are a serious threat to both public and veterinary health. In this study, we used high-throughput sequencing to characterize the virome of three tick species implicated in the spread of vector-borne disease throughout Croatia. Ten viruses were identified, including seven potential novel species within the viral families Flaviviridae, Nyamiviridae, Rhabdoviridae, Peribunyaviridae, Phenuiviridae, and Nairoviridae.     

Effects of Apnea,Obesity, and Statin Therapy on Proprotein Convertase Subtilisin/Kexin 9 Levels in Patients with Obstructive Sleep Apnea

ObjectivesObstructive sleep apnea (OSA) is a common condition closely related to obesity, insulin resistance, dyslipidemia, and cardiovascular disease. The aim of this study was to explore the possible relationship between OSA and proprotein convertase subtilisin/kexin type 9 (PCSK9).MethodsFull-night polysomnography was performed on 150 participants who were divided into three groups: controls, OSA patients on statin therapy, and OSA patients not on statin therapy. Biochemical markers, plasma low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subclasses, and PCSK9 were determined.ResultsPCSK9 was highest in OSA patients on statins compared to the control group and to OSA patients not on statins (p = 0.036 and p = 0.039, respectively), after adjustment for body mass index (BMI). LDL diameter was greater in OSA patients not on statins compared to OSA patients on statins (p = 0.032). PCSK9 was highest in the group of patients with all three risk factors (diagnosed OSA, statins, BMI ≥25 kg/m²) compared to groups with no, one, and two risk factors (p = 0.031, p = 0.001, and p = 0.029, respectively). Presence of OSA, statin therapy, and BMI ≥25 kg/m² when combined were independently associated with higher levels of PCSK9 when adjusted for antihypertensive therapy, small dense LDL, and HDL 3c subclass (odds ratio = 2.849; interquartile range [1.026–7.912], p = 0.044).ConclusionStatin therapy was closely related to PCSK9. OSA along with obesity and statin use induces elevation of PCSK9.