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Biomedical subjects

R Santos

Publications and source records attributed to R Santos.

At least 91 records · Page 5Linked to original sources
PubMed1979

Management of subretinal and vitreous cysticercosis: role of photocoagulation and surgery.

Treatment of intraocular cysticercosis requires selection of the proper method, prevention of complications, and careful follow-up. Small subretinal cysticercus can be treated with xenon or argon photocoagulation. Macular cysticercus are extracted through a sclerochoroidal incision. Large cysticercus can be removed in selected cases with an outcome probe placed in the subretinal space. Cysticercus in the vitreous should be removed with a suction-cutter probe via the pars plana.

Cysticercosis↗
PubMed1979

[Clinical and dermatological aspects of advanced breast cancer. Its relation with therapy and prognosis].

Seventy patients with locally progressive and/or recurrent mammary cancer or with metastatic lesions located on the area of the surgical procedure were evaluated. Several clinical parameters related to the natural history of the disease were outlined. Some of them kept a close link with the therapeutical results. A dermatological classification of the local recurrencies was made based on the clinical aspects. The improvement of the local recurrencies was classified as total or partial according to the response to the treatment. The association of chemotherapy, anabolic drugs and corticosteroids was the uniform treatment for all the cutaneous lesions. Some of these patients achieve a good therapeutical result. These were the patients with a free interval of more than two years and those with bilateral cancer who have had surgical excision. The other group formed by patients where adrenalectomy was performed or with local recurrencies before the two years period has developed a shorter survival time than the first group. The combined of chemotherapy and hormone treatment is useful in dealing with local recurrent or metastatic skin lesions of mammary cancer.

Breast Neoplasms↗
PubMed1978

Ultrastructure and cytochemistry of Miocene angiosperm leaf tissues.

Angiosperm leaf fossils (16.7-25 x 10(6) years by potassium/argon dating) referable to Zelkova were isolated from pyroclastic deposits in the Succor Creek Formation, Oregon. These fossils reveal a three-dimensional structure in mesophyll cell layers and vascular bundles, while transmission electron microscopy of fixed tissues reveals well-preserved chloroplasts with grana stacks and starch, as well as nuclei with condensed chromatin. Transmission electron microscopy indicates that cell walls retain a cellulosic microfibrillar architecture, while ultrastructural and cytochemical confirmation is presented for chloroplast starch and the presence of native cellulose. The preservation of cell walls and cytologic structures in fossil materials of this age indicates an unusually mild fossilization process attending the post-depositional maturation of associated sediments. The preservation observed appears to be associated with rapid physical dehydration coupled with endogenous fixation by organic acids (possibly tannins and/or chlorophyll derivatives).

Journal Article↗
PubMed1975

Retinal microangiopathy in systemic lupus erythematosus.

We performed complete ocular examination, including fluorescein angiography of the fundus, in 50 ambulatory patients with moderately active or inactive systemic lupus erythematosus; none had ocular symptoms. One patient had drusen and two patients had increased intraocular pressures with disk cupping attributable to orally administered corticosteroids. No patient had detectable abnormalities by ophthalmoscopic examination. Despite this apparently normal condition, fluorescein angiography revealed single or multiple microaneurysms in nine patients (13 eyes) and retinal capillary dilatations with leakage of fluorescein in six patients (six eyes). Both abnormalities occurred in two patients. These capillary changes in moderately ill patients with lupus erythematosus are probably the residue of previous acute vasculitis, perhaps due to immune-complex deposition.

Aneurysm↗
PubMedDate not supplied

How REM sleep deprivation and amantadine affects male rat sexual behavior.

There are conflicting findings about the sexual effects of REM sleep deprivation (REMd). Otherwise, several studies show a dopaminergic hypersensitivity after REMd. The effect of REMd and amantadine (AMA) was studied for standard measures and temporal patterning in the first experiment, in four groups: normal with vehicle, normal with AMA (5.0 and 10 mg/kg), REMd with vehicle and REMd with AMA (5.0 and 10.0 mg/kg). REMd reduced mount latency (ML), intromission latency (IL) and mount number (MN) and increased copulatory efficiency (CE) and hit rate factor. REMd also reduced the mount bout number (MBN) and increased the sexual interaction (mount bout time, MBT) among male and female during copula. AMA stimulates initiation and hit rate factors and accelerates the temporal patterning of sexual behavior, evoking fewer and quicker mount bouts. In the experiments with combination of REMd and AMA administration, AMA did not increase behavior effects evoked by REM deprivation, probably due to a top or a bottom effect, depending on the measures considered. A second experiment studied the effects of AMA (1.25 to 5.0 mg/kg) and REMd on the sexual reflexes of nonimmobilized male rats. REMd enhanced the AMA effects upon the seminal emission reflex, but inhibited the penile erection reflex elicited by 1.25 mg/kg of AMA. Curiously, our results showed that REMd, like AMA, a dopaminergic agonist, causes similar effects of sexual behavior in the male rat, particularly those related to arousal mechanism and hit rate factor. The results are discussed and the effects of REMd probably involve dopaminergic hypersensitivity and increased sexual motivational response.

Amantadine↗
PubMedDate not supplied

[Solitary fibrous tumor. Two additional cases with urologic implications].

Solitary fibrous tumour is a well defined pathological entity originally described as a tumour of the pleura, but the occurrence of this neoplasm has increasingly been described at other sites. At present the development of these tumours is recognized as possible in virtually all anatomical sites. The rarity of this type of pathology has not allowed up to the present time clarification of the histogenesis, clinical behaviour, treatment and prognosis of these tumours. Differential diagnosis becomes important, especially in extra-thoracic sites so as not to mistake them for much more aggressive mesenquimal tumours. Two additional cases of this neoplasm are presented, one of them responsible for obstructive uropathy, accidentally found in a patient suffering renal trauma. The second tumour was located in the spermatic cord. A review of the theme is presented based on the available literature.

Aged↗
PubMedDate not supplied

Validation of a new computerized system for recording and analysing drug-induced tremor in rats.

INTRODUCTION: Certain drugs can induce tremor in small animals and can be used as Parkinson's disease or essential experimental tremor models. However, the use of arbitrary scales for evaluating tremor in experimental models is limited by observer subjectivity. Progress in electronics and computer science has allowed a more precise quantification of tremor. The objective of the present study was to validate a newly developed low-cost method of spectral registration and analysis of tremor in free-moving rats. METHODS: Male Wistar rats, 3-4 months of age, previously placed for 5 min inside a sensor cage, were administered with different doses of eserine (0.25-1.5 mg/kg), oxotremorine (0.25-1.5 mg/kg) or harmaline (7.5-60 mg/kg). Drug-induced tremor was recorded during 10 min using a computerized system composed of force transducers, a signal conditioning circuit, a digitizing interface and a microcomputer. The signal transmitted to the computer was quantified, stored and analyzed for its amplitude and frequency by means of specific programs. RESULTS: Tremor was induced with an amplitude that was dose-dependent for all drugs used. Tremor frequency was dose-dependent for oxotremorine and eserine, but not for harmaline. The performance of the system was compared with that of other systems described in behavioral instrumentation literature. DISCUSSION: The present data indicate that the new system is capable of detecting the tremor induced by drugs, and that the programs used for spectral analysis allow the quantification of the amplitude and the frequency of the tremor in free-moving rats.

Animals↗