Photodynamic therapy in Argentina

The use of endogenous Protoporphyrin IX generated through the heme biosynthetic pathway after administration of 5-aminolevulinic acid (ALA) has led to many applications in photodynamic therapy (PDT). In Buenos Aires, Argentina, the Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), reported for the first time, in 1975, porphyrin synthesis from ALA in highly dividing plant tissues. Increased porphyrin synthesis in tumours as well as cell photosensitisation was reported soon after. Our group is also interested in studying the use of new synthetic lipophilic derivatives of ALA as well as ALA delivery in liposomes. We have elucidated the mechanism of ALA transport in mammalian and yeast cells. The interactions between ALA-PDT and nitric oxide were investigated in three murine adenocarcinoma cell lines. In the National University of Río Cuarto, Córdoba, a group is devoted to the synthesis of new porphyrin-derived photosensitisers to study their effects on photoinactivation of bacterial and mammalian cells death by PDT. At the Centre of Electron Microscopy of the Cordoba National University, a prototype of a 630 nm noncoherent light source was designed and constructed. Cost of the light source and scarce knowledge of the benefits of PDT by physicians limit the spread of the treatment throughout the country.     

Female pelvic floor. Descriptive anatomy and clinical exploration by transvaginal ultrasound

In order to assess the state and pathology of the woman's pelvis minor, a number of methods are commonly used among practitioners, encompassing clinical exploration, radiology, MRN, urodynamics, endoscopy and echography.

Echography has been poorly used in clinical pelvic exploration and its reliability is actually a matter of controversy 1. However, echographic surveys can provide us with valuable gynecological data on the state and pathologies of the soft pelvis, within the genital regions or even going beyond them, i.e. the rectal channel, bladder, urethra, anus, vascular plexuses, and all of their supporting tissues.

At our research unit, we have been employing Transvaginal Ultrasound echography (TVU) for a long time in conjunction with other pelvis-focused methods in order to study different kinds of pelvic alterations. TVU has proven to be friendly to use, fast, harmless and inexpensive, allowing serial explorations and producing high-quality dynamic images (loop-cinema, video-tape). Furthermore, this method is fairly aseptic in that the occurrence of faeces in the rectal ampolla is not a nuisance but a bonus in tracking the contours of the rectum walls and other topographical features which would be otherwise difficult to survey.

A complete pelvic floor TVU may add no longer than 5-8 minutes to a routine gynecological examination, can be implemented by the general gynecologist and generates data that can be further studied by the appropriate specialist for a more insightful evaluation 2.     

Implications of postvaccination hepatitis B surface antigenemia in the management of exposures to body fluids.

A neonate vaccinated against HBV was the source of an occupational exposure to blood. She was tested for hepatitis B surface antigen and found to be positive, leading to unnecessary treatment, retesting, and concern. Evaluation of the infectious status of HBV should rely on other means if vaccination has recently occurred.     

Paraxanthine displaces the binding of [3H]SCH 23390 from rat striatal membranes

We present evidence showing that paraxanthine (1,7-dimethylxanthine), the main metabolite of caffeine in man, displaces the binding of [3H]SCH 23390, a radioligand which selectively labels dopamine D-1 receptors when used at low concentrations, from striatal membranes of the rat. The displacement was competitive and indicated the existence of two affinity states (Hill coefficient = 0.49; K(high) = 0.15 microM; K(low) = 95.9 microM, %R(high) = 32.4). When the stable GTP analog Gpp(NH)p was included, the displacement curve indicated the presence of only the low-affinity state (Hill coefficient = 1.16; Ki = 72.1 microM). However, paraxanthine did not displace the specific binding of [3H]spiperone. After injection of 30 mg/kg s.c. of caffeine, a maximum of 10 microM of paraxanthine was found in striatal homogenates, which could be sufficient to occupy dopamine D-1 receptors. Our results suggest that a dopaminergic action of paraxanthine could be involved in the behavioural stimulation produced by caffeine.     

Myoclonic movements as a side-effect of treatment with therapeutic doses of clomipramine

Myoclonic movements have been observed in depressed patients receiving therapeutic doses of clomipramine. Such movements, which appear in states of deep muscular relaxation such as sleep, do not appear to have any repercussion in the outcome of the depression and are reversible following withdrawal of the drug. In this study the plasma levels of clomipramine and desmethylclomipramine were determined and their possible relationship with myoclonus studied. No statistically significant relationships were found.     

Isoflurane in pulmonary hypertension and failure of the right ventricle

We evaluated the effects of the use of 1.2% isoflurane (group A) in a group of patients (n = 13) referred for mitral valve surgery, with pulmonary hypertension and right ventricular failure. We evaluated the hemodynamic status in baseline conditions, after isoflurane ++ administration and in relative hyper- and hypovolemia. We compared the results with those in 17 patients (group B) in identical clinical state who did not receive isoflurane during anesthesia. The evaluated parameters were: mixed venous Hb saturation (SvO2), heart rate (HR), pulmonary capillary pressure (PCP), central venous pressure (CVP), mean blood pressure (mBP), mean pulmonary arterial pressure (mPAP), cardiac index (CI), arteriolar pulmonary resistances (APR), peripheral vascular resistances (SVR), stroke index (SI), left ventricular work (LVW), right ventricular work (RVW), and O2 consumption (VO2). In group A, after isoflurane ++ administration, CI was 107.05% and 80% of baseline values in relative hypervolemia and hypovolemia, respectively. In group B (control), CI was 121.48% and 88.28% of basal values in relative hypervolemia and hypovolemia, respectively. In group A, SVR were 73.59% and 76.72% in hypervolemia and hypovolemia, respectively, while in group B they were 86.21% and 106.80%. In group A, APR were 90.85% and 89.96% in hypervolemia and hypovolemia, while they were 80.72% and 102.34% in group B. We found that isoflurane results in a greater peripheral than pulmonary vasodilation with a greater impairment in right ventricular function.     

Role of DAT‐SPECT in the diagnostic work up of Parkinsonism

The diagnosis of idiopathic Parkinson's disease (PD) can be achieved with high degrees of accuracy in cases with full expression of classical clinical features. However, diagnostic uncertainty remains in early disease with subtle or ambiguous signs. Functional imaging has been suggested to increase the diagnostic yield in parkinsonian syndromes with uncertain clinical classification. Loss of striatal dopamine nerve terminal function, a hallmark of neurodegenerative Parkinsonism, is strongly related to decreases of dopamine transporter (DAT) density, which can be measured by single photon emission computed tomography (SPECT). The use of DAT‐SPECT facilitates the differential diagnosis in patients with isolated tremor symptoms not fulfilling PD or essential tremor criteria, drug‐induced, psychogenic and vascular Parkinsonism as well as dementia when associated with Parkinsonism. This review addresses the value of DAT‐SPECT in early differential diagnosis, and its potential as a screening tool for subjects at risk of developing PD as well as issues around the assessment of disease progression. © 2007 Movement Disorder Society