Biomedical subjects

P Barzó

Publications and source records attributed to P Barzó.

At least 19 recordsLinked to original sources

PubMed1997

Detection of brain atrophy following traumatic brain injury using gravimetric techniques.

We hypothesized, that with atrophy, the correlation between water content and specific gravity of brain solids would break down signifying the onset of the atrophic process. The correlation between tissue water content, specific gravity of solids and ventricular size was studied in an impact acceleration model of closed head injury of the rat. Adult Sprague Dawley rats weighing 350 to 375 grams (n = 63) were separated into two groups: Group 1: Sham (n = 21), Group II: Trauma (n = 42). Water content was assessed using both gravimetric method and drying-weighing method at 1 hour, on days 1, 3, 7, 14, 28, and 42 in the trauma group as well as in the control group. Ventricular size was measured in cm2 on the MRI computer console in the coronal section at the coronal suture at the same time points. In the trauma group we found a significant increase (p < 0.01) in water content during the first week except on day 3 and there was a good correlation between the results of water content using both methods (p < 0.001). However, this relationship was poorly correlated after day 14 (p = 0.25). Although the ventricular size was the smallest at 1 hour post trauma, it significantly increased over the next 3 days (p < 0.001). On day 7 and 14 ventricular size decreased to normal size, yet gradually increased and then reached a significantly larger size on 42 days post trauma again (p < 0.01). We may consider, that brain edema following CHI begins immediately following trauma and resolves within 2 weeks. After 14 days degenerative change occurs in the cortex, as detected by specific gravity measurements which signifies the onset of the atrophic process and subsequent post traumatic ventricular dilatation.

Animals↗

PubMed1997

MRI diffusion-weighted spectroscopy of reversible and irreversible ischemic injury following closed head injury.

The objective of this study was to detect the threshold between reversible and irreversible secondary insult of hypoxia and hypotension following closed head injury as measured by MRI. Adult Sprague rats were separated into 3 groups: I: Sham (n = 6), II: Trauma and hypoxia coupled with mild hypotension of 40-50 mmHg (n = 6), III: Trauma and hypoxia coupled with severe hypotension of 30-40 mmHg (n = 6). The measurement of brain water content (BWC) was based on T1, whereas the differentiation between reversible and irreversible secondary insult on the measurement apparent diffusion coefficient (ADC). The ADCs in both trauma and secondary insult groups decreased rapidly from a control level of 0.68 +/- 0.5 x 10(-3) to significantly different minimum levels of 0.52 +/- 0.5 x 10(-3) in Group II and 0.42 +/- 0.5 x 10(-3) mm2/second in Group III at 30 minutes. In Group II rats there was a complete recovery in ADC as well as in their clinical conditions, whereas ADC in Group III rats remained at the minimum level and the animals were brain dead. The BWC was also significantly different at four hours post injury (Group II: 80.3 +/- 0.7%, Group III: 81.8 +/- 0.8%). The data lead the authors to suggest that the threshold between reversible and irreversible posttraumatic secondary insult is very narrow, and the measurement of ADC can provide information that will enable the clinician to identify critical threshold beyond which recovery is not possible.

Animals↗

PubMed1997

Biphasic pathophysiological response of vasogenic and cellular edema in traumatic brain swelling.

The objective of this study was to quantify the temporal water content changes and document the type of edema (cellular versus vasogenic) that is occurring during both the acute and the late stages of edema development following closed head injury. Adult Sprague rats (n = 50) were separated into two groups: Group I: Sham (n = 8), Group II: Trauma (n = 42). The measurement of brain water content (BWC) was based on T1, whereas the differentiation of edema on the measurement of the random, translational motion of water protons (apparent diffusion coefficients-ADC) by MRI. In trauma animals, we found a significant increase in ADC (105%) as well as in BWC (0.7 +/- 0.3%) during the first 60 minutes post injury indicating vasogenic edema formation. This transient increase; however, was followed by a continuing decrease in ADC beginning at 45 minutes post injury and reaching a minimum at days 7-14 (-103%). Since the BWC continued to increase during the next day (10.3%), it is suggested cellular edema formation started to develop soon after injury and became dominant between 1-2 weeks post injury. In conclusion we may consider, that there is a predominantly vasogenic edema formation immediately after injury and later a more widespread and slower edema formation due to a predominantly cellular swelling.

Animals↗

PubMed1997

Acute blood-brain barrier changes in experimental closed head injury as measured by MRI and Gd-DTPA.

The objective of this study was to determine the early time course of blood-brain barrier (BBB) changes in diffuse closed head injury (CHI) and to what extent BBB is affected by secondary insult. The BBB disruption was quantified using T1-weighted MRI following administration of Gd-DTPA. The maximal signal intensity (SI) enhancement was used to calculate BBB disruption. A new CHI model was used to induce injury. Adult SD rats were separated into four groups: Group I: Sham (n = 4), II: Hypoxia and Hypotension (HH, n = 4), III: Trauma alone (n = 23), and IV: Trauma coupled with HH (THH, n = 14). Following trauma, a 30 minute insult of hypoxia (PaO2 = 40 mmHg) and hypotension (MABP = 30 mmHg) were imposed. In trauma animals, SI increased dramatically immediately following impact. By 15 minutes, permeability decreased exponentially and by 30 minutes was equal to that of control. In THH animals, SI enhancement was lower after the trauma, consistent with reduced blood pressure and blood flow. However, the SI increased dramatically upon reperfusion and was equal to that of control after 60 minutes. In conclusion we may consider, that CHI is associated with a rapid and transient BBB opening which begins at the time of the trauma and lasts not more than 30 minutes. It has been also shown that addition of hypoxia and hypotension prolongs the time of BBB breakdown.

Animals↗

PubMed1997

Contribution of vasogenic and cellular edema to traumatic brain swelling measured by diffusion-weighted imaging.

The contribution of brain edema to brain swelling in cases of traumatic brain injury remains a critical problem. The authors believe that cellular edema, the result of complex neurotoxic events, is the major contributor to brain swelling and that vasogenic edema, secondary to blood-brain barrier compromise, may be overemphasized. The objective of this study, therefore, was to quantify temporal water content changes and document the type of edema that forms during the acute and late stages of edema development following closed head injury (CHI). The measurement of brain water content was based on magnetic resonance imaging-determined values of tissue longitudinal relaxation time (T1-weighted imaging) and their subsequent conversion to percentage of water, whereas the differentiation of edema formation (cellular vs. vasogenic) was based on the measurement of the apparent diffusion coefficient (ADC) by diffusion-weighted imaging. A new impact-acceleration model was used to induce CHI. Thirty-six adult Sprague-Dawley rats were separated into two groups: Group I, control (six animals); and Group II, trauma (30 animals). Fast ADC measurements (localized, single-voxel) were obtained sequentially (every minute) up to 1 hour postinjury. The T1-weighted images, used for water content determination, and the diffusion-weighted images (ADC measurement with conventional diffusion-weighted imaging) were obtained at the end of the 1st hour postinjury and on Days 1, 3, 7, 14, 28, and 42 in animals from the trauma and control groups. In the animals subjected to trauma, the authors found a significant increase in ADC (10 +/- 5%) and brain water content (1.3 +/- 0.9%) during the first 60 minutes postinjury. This is consistent with an increase in the volume of extracellular fluid and vasogenic edema formation as a result of blood-brain barrier compromise. This transient increase, however, was followed by a continuing decrease in ADC that began 40 to 60 minutes postinjury and reached a minimum value on Days 7 to 14 (10 +/- 3% reduction). Because the water content of the brain continued to increase during the first 24 hours postinjury (1.9 +/- 0.9%), it is suggested that the decreased ADC indicated cellular edema formation, which started to develop soon after injury and became dominant between 1 and 2 weeks postinjury. The study provides supportive evidence that cellular edema is the major contributor to posttraumatic swelling in diffuse CHI and defines the onset and duration of the increase in cellular volume.

Acceleration↗

PubMed1996

[Cerebral blood flow studied by SPECT and transcranial Doppler sonography in subarachnoid hemorrhage].

The detection of vasospasm plays an important role for the definition of the strategy of treatment in patients with subarachnoid hemorrhage (SAH). Besides the invasive contrast angiography, the non-invasive 99m-Tc-HMPAO brain perfusion SPECT and transcranial Doppler sonography (TCD) are recently used for this purpose. For the investigation of the possibilities of the last two methods, comparative studies were performed in 29 SAH patients in the subacute phase of the disease. In the detection of regional brain ischaemia the sensitivity of the SPECT study was 90%, the specificity was 28% and the accuracy was 50%, the corresponding values of TCD were 82%, 71% and 75%. In patients, in whom chronic neurological symptoms, or morphological abnormalities could be excluded, the specificity of the SPECT study was 67% at unchanged sensitivity. Based on the results it is concluded, that the brain perfusion SPECT and the TCD investigation are useful methods for the detection of vasospasm after SAH. The combination of the two methods is recommended for the correct diagnosis of vasospasm in SAH. Further investigations are necessary to clarify the prognostic impact of the result of these investigations.

Adult↗

PubMed1996

Use of transcranial Doppler sonography and acetazolamide test to demonstrate changes in cerebrovascular reserve capacity following carotid endarterectomy.

OBJECTIVES: To assess the effect of carotid endarterectomy on cerebrovascular reserve capacity. METHODS: Cerebral blood flow velocity (CBFV) and cerebrovascular reserve capacity (CVRC) were measured by transcranial Doppler sonography (TCD) and acetazolamide test in 40 patients who underwent uncomplicated unilateral carotid endarterectomy (CEA). Indication for operation was limited to stenoses > 70% as documented by angiography and/or Duplex scanning. The TCD studies were carried out 6 days (range 1-14 days) before and 8 days (range 5-12 days) after endarterectomy. RESULTS: Before endarterectomy, resting CBFV values and CVRC in the 40 patients were significantly different between the operated (51 +/- 19 cm/s; 20 +/- 16%) and the non-operated (60 +/- 19 cm/s; 34 +/- 24%) hemisphere (p < 0.05;p < 0.01). After CEA the overall increase of resting CBFV of the operated side was highly significant with preoperative CBFV values of 51 +/- 19cm/s and postoperative values of 62 +/- 15 cm/s (p < 0.01). Cerebrovascular reserve capacity after operation was increased on both sides significantly (non-operated side: from 34 +/- 24% to 43 +/- 19%, p < 0.05; operated side: from 20 +/- 16% to 51 +/- 18%, p < 0.001), and the preoperative asymmetry was no longer present. CONCLUSIONS: CEA has a beneficial effect on the cerebral circulation in most patients, even those who presented with asymptomatic carotid artery stenosis. Since CVRC has been assessed in the early postoperative period, our findings also suggest that cerebral vascular adaption occurs within 2 weeks after CEA.

Acetazolamide↗

PubMed1996

Characterization of edema by diffusion-weighted imaging in experimental traumatic brain injury.

The objective of this study was to use diffusion-weighted magnetic resonance imaging (DWI) to help detect the type of edema that develops after experimental trauma and trauma coupled with hypotension and hypoxia (THH). Reduction in the apparent diffusion coefficients (ADCs) is thought to represent cytotoxic edema. In a preliminary series of experiments, the infusion edema model and middle cerebral artery occlusion models were used to confirm the direction of ADC change in response to purely extracellular and cytotoxic edema, respectively. The ADCs increased (p<0.05) in the case of extracellular edema and decreased (p<0.001) in cytotoxic edema. Following these initial experiments, a new impact acceleration model was used to induce traumatic brain injury. Thirty-six adult Sprague-Dawley rats were separated into four groups; sham, trauma alone, hypoxia and hypotension (HH), and THH. Following trauma, a 30-minute insult of hypoxia (PaO2 of 40 mm Hg) and hypotension (mean arterial blood pressure (MABP) of 30 mm Hg) were imposed and the animals were resuscitated. The DWI was carried out at four 1-hour intervals postinjury, and MABP, intracranial pressure (ICP), cerebral perfusion pressure (CPP), and cerebral blood flow (CBF) were monitored. The ADCs in the control and HH groups remained unchanged. The ADCs in the THH group rapidly decreased from a control level of 0.68 +/- 0.05 x 10(-3) mm2/second to 0.37 +/- 0.09 x 10(-3) mm2/second by 3 hours posttrauma (p < 0.001). In this group, the decreased CBF and CPP during secondary insult remained low despite resuscitation, with the ICP increasing to 56 +/- 7 mm Hg by 3 hours. In the trauma alone group, the rise in ICP reached a maximum value (28 +/- 3 mm Hg) at 30 minutes with a significant and sustained increase in CBF despite a gradual decrease in CPP. The ADCs in this group were not significantly reduced. The data lead the authors to suggest that the rise in ICP following severe trauma coupled with secondary insult in this model is predominately caused by cytotoxic edema and that ischemia plays a major role in the development of brain edema after head injury.

Animals↗

PubMed1996

Magnetic resonance imaging-monitored acute blood-brain barrier changes in experimental traumatic brain injury.

The authors posit that cellular edema is the major contributor to brain swelling in diffuse head injury and that the contribution of vasogenic edema may be overemphasized. The objective of this study was to determine the early time course of blood-brain barrier (BBB) changes in diffuse closed head injury and to what extent barrier permeability is affected by the secondary insults of hypoxia and hypotension. The BBB disruption was quantified and visualized using T1-weighted magnetic resonance (MR) imaging following intravenous administration of the MR contrast agent gadolinium-diethylenetriamine pentaacetic acid. To avoid the effect of blood volume changes, the maximum signal intensity (SI) enhancement was used to calculate the difference in BBB disruption. A new impact-acceleration model was used to induce closed head injury. Forty-five adult Sprague-Dawley rats were separated into four groups: Group I, sham operated (four animals), Group II, hypoxia and hypotension (four animals), Group III, trauma only (23 animals), and Group IV, trauma coupled with hypoxia and hypotension (14 animals). After trauma was induced, a 30-minute insult of hypoxia (PaO2 40 mm Hg) and hypotension (mean arterial blood pressure 30 mm Hg) was imposed, after which the animals were resuscitated. In the trauma-induced animals, the SI increased dramatically immediately after impact. By 15 minutes permeability decreased exponentially and by 30 minutes it was equal to that of control animals. When trauma was coupled with secondary insult, the SI enhancement was lower after the trauma, consistent with reduced blood pressure and blood flow. However, the SI increased dramatically on reperfusion and was equal to that of control by 60 minutes after the combined insult. In conclusion, the authors suggest that closed head injury is associated with a rapid and transient BBB opening that begins at the time of the trauma and lasts no more than 30 minutes. It has also been shown that addition of posttraumatic secondary insult-hypoxia and hypotension-prolongs the time of BBB breakdown after closed head injury. The authors further conclude that MR imaging is an excellent technique to follow (time resolution 1-1.5 minutes) the evolution of trauma-induced BBB damage noninvasively from as early as a few minutes up to hours or even longer after the trauma occurs.

Animals↗

PubMed1995

[Bronchiolitis obliterans organizing pneumonia: survey based on two cases].

Authors offer a survey about an aspect forming a clinical entity called bronchiolitis obliterans organizing pneumonia, by two of their patients' presentation. In Case 1 the process manifested in form of a disseminated, small spotted, diffuse shadow, causing serious resting hypoxia. Diagnosis was supported by histological examination of a substance obtained by small surgical thoracotomy. Five months' therapy of Imuran and altogether 15 months' therapy of Prednisolon resulted in recovery. Second patient's symptoms and the shadow representated in the left upper lung field on chest X-ray, proposed the probability of a tumour. The lesion removed surgically, together with the left upper lobe, proved to be the clinical appearance that constitutes histologically the subject of this paper. Surgery alone resulted in definitive recovery. Disease can be proved on the basis of histological picture and it's important to sunder it primarily from bronchiolitis obliterans as well as from other interstitial pulmonary diseases.

Adult↗

PubMed1995

Our policy in diagnosis and treatment of hydrocephalus.

The authors present the policy they have worked out for hydrocephalus patients with special reference to the pressure measurement and test methods and to rCBF, SPECT and transcranial Doppler sonography (TDC) studies. For diagnosis, the protocol proposed by Gjerris and Borgesen was followed in 75 cases: besides other methods (CT, radionuclide cisternography, MRI) the intracranial pressure waves routinely recorded and analyzed by means of ventricular catheters for 24 h. The patients were roughly divided into groups in terms of diagnosis, baseline pressure, compliance, results of infusion tests and of surgery. In 13 patients the investigations were supplemented by rCBF SPECT and in 42 patients by TCD studies before and after CSF shunting or withdrawal to analyze the acute effects on cerebral circulation. Clinical follow-up shows that need for shunting was indicated fairly well by the common results of baseline ICP, compliance and infusion loading. The rCBF SPECT studies revealed a significant increase of the cerebral perfusion at the basal ganglia after shunting while, on the basis of CBF velocity changes three types of vasoregulatory response could be defined with TCD. In our hands, monitoring of the pressure and craniospinal capacity has proved to be a valuable aid in decisions on surgery; however, for a more precise (and beneficial) appreciation of whether surgery is indicated the vasoregulatory responses should also be taken into account in future.

Blood Flow Velocity↗

PubMed1994

[Primary malignant melanoma of the lung and lower respiratory tract].

After detailed analysis of the international special literature, the authors found--together with their own two patients--only 18 cases, considered primer malignant melanoma of the lower respiratory tract and/or lung. Of the accepted criteria, they dispute the obduction's absolute evidentiary role, because among primer patients there are the most who survives, even a decade. In seven cases tumour was located endobronchially and in one patient in the trachea. It was manifested endobronchially and on the dependent lung-areas, simultaneously in two patients and merely parenchymally, in eight. There was a successful resection in fourteen of 18 cases. Survival was influenced primarily by the operability depending on distension of the tumour. Besides procedures forming opinions, bronchoscopy and histological examinations of bioptatum gained this way play a greater role than usual in determining the tumour's primarity, localisation, operability and type of surgery, respectively. Namely, only operated patients can rely on a long survival.

Adult↗

PubMed1994

Evaluation of cerebral vasoreactivity by SPECT and transcranial Doppler sonography using the acetazolamide test.

rCBF SPECT with 99mTc-HMPAO was performed prospectively in 29 patients (3 controls and 26 stroke patients) as well as TCD studies in 20 patients (3 controls and 17 stroke patients) before and after 1 g i.v. acetazolamide. The sensitivity of rCBF SPECT increased from 62% to 77% after acetazolamide provocation in stroke patients. In patients with a reversible neurological deficit, the sensitivity under resting conditions was 50% which increased to 71%, while in cases with a permanent deficit it increased from 75% to 83%. In the evaluation of the cerebrovascular reserve capacity the results of rCBF SPECT and TCD coincided in 91% of the hemispheres. The correlation was statistically significant.

Acetazolamide↗

PubMed1993

[Clinical significance of lumbosacral transitional vertebrae (Bertolotti syndrome)].

500 lumbosacral plain x-ray injured patients and 1000 myelography of patients suffering from low back pain and nerve root sign were reviewed to evaluate the rate of transitional lumbosacral vertebra. This anomaly appeared in 4.6% in the normal population. The rate of the transitional vertebra in patients with nerve root syndrome was double (8.4%) whereas that with lumbar disc herniation four time as many as in the normal population. The data demonstrate that the asymmetrical anomalies have more clinical significance. The authors consider, that the role of the transitional vertebra is twofold: it can be consider primary in low back and sciatic pain, but in the formation of lumbar disc herniation is secondary. They find the analysis of the lumbosacral plain x-ray is necessary even in cases with CT and MRI.

Humans↗

PubMed1993

[Aspiration of barium contrast medium and its prevention].

The authors have been noted aspiration bronchograms associated with barium-filling study of the upper gastrointestinal tract in 58 patients involving basal medial, anterior, lateral and posterior segments of the lower pulmonary lobes, mammary segment of the middle lobe, moreover inferior lingula. In 75.9% of patients (44 cases) the barium meal got to bilateral basal medial, anterior and lateral segments. The 34 men and 24 women had a mean age of 69 years (range, 29-88 years). The aspiration was found 3.8-times more frequent after completion of patient's 50th year than before it observed. A transient tertiary mobility disorder of the esophagus, extrasystoles and tendency for collapse were on barium-filling of bronchi. In 15 of the 18 patients the Valsalva's maneuver proved a pharyngomyodystonia. Carrying out of endoradiography depended on function of the lateral pharyngeal wall. The bronchi with physiological saline following aspiration of the contrast medium within 30 minutes were lavaged.

Adult↗

PubMed1993

[Cardiorespiratory and electrolytic changes in status asthmaticus after intravenous administration of magnesium sulfate].

The authors studied cardiorespiratory effects of MgSO4 infusion in 30 randomized patients with status asthmaticus. They found, that after having the drug administered, values of VC, FEV1, FIV1, PaO2 and pH increased, the respiratory and heart rate, diastolic blood pressure reduced. Other ventilation, blood gas and ECG parameters were unchanged. Among the electrolytes, serum Ca2+ level has reduced, both plasma and intracellular Mg2+ concentrations increased. It is apparent from the results, that broncholytical ability of MgSO4 given in therapeutical dose i.v. does not reach the level of beta-stimulating agents. However, this completed with the cardioprotective, sedative effect as well as more advantageous ion-distribution, influences favourably the asthmatic dyspnoea.

Adolescent↗

PubMed1993

[The effect of carotid endarterectomy on the reserve capacity of cerebral blood flow velocity].

Cerebral blood flow velocity was measured by transcranial Doppler sonography at rest and during cerebral vasodilatation evoked with acetazolamide in 14 patients before and after carotid endarterectomy. Before surgery the vasoreactivity in the affected middle cerebral artery territories was reduced and abnormal (asymptomatic side: 35.9 +/- 25.6% [mean +/- SD; n = 14]; symptomatic side: 25.6 +/- 10.7%), but the difference between the two hemispheres was not significant however, vasoreactivity was normalized 5 days after surgery (asymptomatic side: 46.9 +/- 22.3% symptomatic side: 58.9 +/- 23%) (p < 0.001). The increase in cerebral reserve capacity and changes in Gosling's index of pulsatility correlated significantly in both hemispheres (p < 0.02). This findings indicate an improved perfusion reserve on the fifth day following carotid endarterectomy in patients with an internal carotid artery diameter reduction of at least 70%.

Blood Flow Velocity↗

PubMed1993

[Bronchoalveolar lavage in the confirmation of pulmonary involvement in chronic lymphoid leukemia].

The authors made bronchoalveolar lavage (BAL) for explaining the origin of diffuse bilateral lung--infiltration in patients with chronic lymphoid leukaemia. On the base of lavage-fluid, the lung damage may be caused by leukaemic infiltration. The lesion has not changed by antibiotic therapy, but was radiologically cured after giving corticoids. The authors have not read about approaching chronic lymphoid leukaemic pulmonary infiltration by BAL. They call attention to the etiologic clarification of lung organs' complications in haematological aspects and outstanding role of BAL as a non-invasive method.

Aged↗