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J Tejada

Publications and source records attributed to J Tejada.

46 records · Page 3Linked to original sources
PubMed1987

Vascular casts demonstrate microcirculatory insufficiency in acute frostbite.

The use of vascular microcorrosion casts (vascular replicas) has made it possible to demonstrate the degree of damage to the microcirculation in experimentally induced frostbite. This approach provides a direct method for demonstrating vascular patency. Four groups of animals were used in this investigation. The left hind limbs of anesthetized rats were cooled to -10 degrees C in groups one and three and to -20 degrees C in groups two and four, as measured by needle thermocouples placed under the gastrocnemius muscles. Thermocouples were also placed in the left hind footpads of groups three and four. The sheathed limbs were cooled in an alcohol bath at approximately 1.1 degree C per minute. All limbs exposed to the cold bath were rewarmed to 37 degrees C in a 40 degree C water bath. The right hind limbs served as uninjured controls. The footpad temperatures recorded in groups three and four were used in conjunction with the temperatures recorded under the gastrocnemius muscles to characterize the footpad temperatures in groups one and two. Vascular microcorrosion casts were made from the left and right hind paws of groups one and two using Batson's modified methyl methacrylate. Scanning electron microscopic examination of the casts demonstrated dramatic differences between the vascular integrity of control paws and that of frozen paws. Exposure to the cold temperatures destroyed most of the microcirculation. In addition, the weights of the casts from the control paws were significantly different from the weights of the casts from the frozen paws. It was concluded that this model for evaluating frostbite injury accurately demonstrates the extent of microvascular damage and has significant potential as a method for evaluating therapeutic drug regimens.

Animals↗
PubMed1977

Investigation of two deoxygenated haemoglobin-haptoglobin complexes by Mössbauer spectroscopy.

Haemoglobin Haptoglobin complexes formed when [Hp+]/[Hb]= 1/1 and [Hp]/[Hb] =2/1 were investigated by 57Fe Mössbauer spectroscopy. Both samples gave a spectrum consisting of a single quadrupole doublet. The temperature dependence of the quadrupole splitting was also identical for both samples. This proves that in both samples the nearest neighbour environment of the iron atom must be the same. A comparison with earlier investigations on myoglobin and haemoglobin indicates that the electronic structure of iron in the HbHp-complexes is similar to that in myoglobin.

Cold Temperature↗
PubMedDate not supplied

[Isolated central nervous system vasculitis manifesting as a pseudotumor].

Vasculitis is characterized by inflammation of the vessel walls, with or without necrosis, that causes narrowing and occasionally obstruction of the vessels. Vasculitis can be a primary process or it can occur secondary to other disease. Isolated central nervous system vasculitis (ICNSV) is a rare type of primary vasculitis that predominately affects the supratentorial regions. The clinical presentation and imaging findings are unspecific and diagnosis is made by exclusion and biopsy. We present a case manifesting as a pseudotumor in the posterior fossa on computed tomography and magnetic resonance imaging. The diagnosis was after biopsy, and the patient evolved favorably after treatment.

Adult↗
PubMedDate not supplied

[Carotid stenosis and lacunar infarct].

INTRODUCTION: Perforating artery disease is still the main cause of lacunar infarcts (LI), while the relationship between this type of ischemia and carotid stenosis (CS) is controversial. OBJECTIVE: To assess the association between CS and LI in patients with criteria of localized ischemia in the carotid territory separately analyzing isolated LI and multiples LIs. PATIENTS AND METHODS: Three hundred and thirty patients with a first episode of cerebral infarct in the area supplied by the carotid artery were registered prospectively. There were 205 LI (135 isolated and 70 multiple) which could be differentiated from 125 non-lacunar infarcts (NLI). The vascular risk factors were determined and the degree of carotid stenosis measured by duplex-colour ultrasound exploration. RESULTS: In the isolated LI group the frequency of presentation of CS greater than 50% was 22% for the artery ipsilateral to the LI and 8% for the contralateral artery. For significant CS (> 70%) frequencies of 14% (ipsilateral) and 8% (contralateral) were observed. On comparative analysis with the NLI group, the presence of stenosis greater than 50 to 70% was significantly higher in these for both ipsilateral and contralateral arteries. In the LI group, isolated CS was significantly more frequent on the side which was homolateral to the ischemia as compared to its isolated presence on the contralateral side (22/30 vs 4/12; OR: 5.5 [95% CI: 1.2-23]). Ipsilateral CS greater than 70% behaved as a factor which was significantly associated with the multiple LI subtype with a unilateral pattern. CONCLUSION: CS should be considered a risk factor for LI.

Aged↗
PubMedDate not supplied

Motor hand recovery after stroke. Prognostic yield of early transcranial magnetic stimulation.

Transcranial magnetic stimulation (TMS) was performed in 20 patients within the first days after stroke. Motor evoked potentials (MEPs) were bilaterally recorded over thenar eminence muscles, and central motor conduction time (CMCT), amplitude of the MEPs (A%M) and threshold intensity compared between both sides. Six months later the patients were reexamined. Within the first days after stroke the obtention of MEPs at rest or during voluntary muscle activation have a favorable prognostic value. All patients with early response by TMS reached a good motor function in the following months. The follow-up showed that the electrophysiological improvement was closely related to clinical recovery of the hand function. However, even in cases with a good recovery, the CMCT and, mainly, the A%M, may be significantly different related to those in normal hand. TMS may be an early and valuable prognostic indicator of hand function recovery after stroke, and their prognostic yield is higher than clinical evaluation and CT study. TMS is a quantifiable method of motor disability and may have practical application in the management and rehabilitation therapy in stroke patients.

Adult↗