The significance of morphological changes in cerebral arteries after subarachnoid hemorrhage

1990 ◽  
Vol 72 (4) ◽  
pp. 626-633 ◽  
Author(s):  
Marc R. Mayberg ◽  
Tomohisa Okada ◽  
Don H. Bark
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Whole Blood ◽  
Vessel Wall ◽  
Structural Changes ◽  
Morphological Changes ◽  
Cerebral Arteries ◽  
Cross Sectional Area ◽  
Ultrastructural Changes ◽  
Sectional Area ◽  
Cross Sectional

✓ A porcine model was developed to allow quantitative assessment of morphological changes in cerebral arteries after subarachnoid hemorrhage and to determine the significance of structural changes in producing arterial narrowing. Whole blood was selectively applied to the middle cerebral artery (MCA) of seven pigs. After 10 days, vessels were perfusion-fixed and examined by light and transmission electron microscopy and immunohistochemistry. The MCA's exposed to whole blood for 10 days showed prominent luminal narrowing associated with profound ultrastructural changes affecting all layers of the vessel wall. Morphometric analysis, however, demonstrated that significant reductions in the luminal cross-sectional area (−55.8% ± 12.5%, p < 0.005) and increases in radial wall thickness (75.1% ± 10.5%, p < 0.005) were associated with only minimal increase in the cross-sectional area of the vessel wall (12.5% ± 15%,p < 0.025). By stereological analysis, the volume density of individual components of the arterial wall was unchanged in MCA's exposed to blood. Vessels exposed to blood showed a 44% reduction in smooth-muscle cell immunoreactive actin and increased collagen in the extracellular matrix of the vessel wall. These data suggest that structural changes in cerebral arteries after subarachnoid hemorrhage do not directly contribute to vessel narrowing through increases in wall mass. Nevertheless, such changes may reflect pathological mechanisms which act to augment prolonged vasoconstriction or inhibit the maintenance of normal vascular tone.

The role of hemoglobin in arterial narrowing after subarachnoid hemorrhage

1990 ◽  
Vol 72 (4) ◽  
pp. 634-640 ◽  
Author(s):  
Marc R. Mayberg ◽  
Tomohisa Okada ◽  
Don H. Bark
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Whole Blood ◽  
Blood Cells ◽  
Vessel Wall ◽  
Cross Sectional Area ◽  
Erythrocyte Membranes ◽  
Ultrastructural Changes ◽  
Sectional Area ◽  
Cross Sectional ◽  
Luminal Narrowing

✓ A porcine model for subarachnoid hemorrhage has been developed to allow the selective application of blood and its components to cerebral arteries. Whole blood was centrifuged to produce two fractions consisting of washed erythrocytes (red blood cells, RBC's) and white blood cells (WBC) plus platelet-rich plasma (PRP); the RBC fraction was subsequently separated into hemoglobin (Hb)-containing cytosol and erythrocyte membranes. Each fraction was selectively applied to the middle cerebral artery (MCA) of pigs for 10 days; after which, vessels were perfusion-fixed and examined by light and transmission electron microscopy and immunohistochemical studies. By morphometric analysis, a marked reduction in the MCA lumen cross-sectional area was observed after selective application of RBC's or Hb/cytosol but not of WBC/PRP or erythrocyte membranes. In both RBC- and Hb/cytosol-treated vessels, luminal narrowing was associated with a differential increase in vessel wall thickness of the ventral (subarachnoid) compared to the dorsal (brain) aspect of the artery, but no significant change in cross-sectional area of the vessel wall. After 10 days of exposure to RBC's or Hb/cytosol, there was a spectrum of ultrastructural changes in the vessel wall comparable to those seen after periadventitial application of whole blood. Selective application of commercially available Hb to MCA produced similar structural and morphometric changes. The degree of luminal narrowing after exposure to whole blood or RBC's was proportional to the volume of the erythrocyte mass adjacent to the vessel at sacrifice. These data suggest that arterial narrowing after SAH is mediated by mechanisms related to prolonged exposure of the vessel wall to hemoglobin or its catabolites from lysing subarachnoid erythrocytes.

scholarly journals Morphological changes during early trans-tibial prosthetic fitting

1998 ◽  
Vol 22 (2) ◽  
pp. 115-122 ◽  
Author(s):  
M. Lilja ◽  
P. Hoffmann ◽  
T. Öberg
Keyword(s):  
Morphological Changes ◽  
Muscle Group ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Transtibial Amputation ◽  
Negative Power ◽  
Lateral Muscle ◽  
Amputation Stump ◽  
The Cross

Morphological changes in the amputation stump may have serious implications regarding the suspension and fit of the prosthetic socket. In an earlier study (Lilja and Öberg, 1997) the authors have shown that the volume of the transtibial amputation stump decreases according to a negative power function after amputation, and that the stump volume does not stabilise until four months after the operation. In the present study, Magnetic Resonance Imaging (MRI) technique was used to examine morphological changes in the amputation stump after transtibial amputation in a small number of cases. The authors expected to find a decrease in the cross-sectional area of the stump and of the separate muscles similar to the findings in earlier studies. However, two different patterns were found. The cross-sectional area of the entire stump as well as that of the medial muscle group changed according to the authors' hypothesis, i.e. an initial fast decrease, followed by a more moderate decrease of the area. In the lateral muscle group another pattern was found. After an initial rapid decrease the area increased, sometimes to a magnitude larger than the initial value. After the amputation the lateral muscle group may acquire a new function, contributing to the suspension of the socket. Despite the limited number of patients, this study presents findings which may be important in the clinical fitting of trans-tibial prostheses.

scholarly journals Controlled Drought Affects Morphology and Anatomy of Salvia splendens

2005 ◽  
Vol 130 (5) ◽  
pp. 775-781 ◽  
Author(s):  
Stephanie E. Burnett ◽  
Svoboda V. Pennisi ◽  
Paul A. Thomas ◽  
Marc W. van Iersel
Keyword(s):  
Polyethylene Glycol ◽  
Morphological Changes ◽  
Stem Elongation ◽  
Cross Sectional Area ◽  
Vessel Element ◽  
Sectional Area ◽  
Cross Sectional ◽  
Salvia Splendens ◽  
Growing Medium ◽  
Peg 8000

Polyethylene glycol 8000 (PEG-8000) was applied to a soilless growing medium at the concentrations of 0, 15, 20, 30, 42, or 50 g·L-1 to impose controlled drought. Salvia (Salvia splendens F. Sellow. ex Roem & Shult.) seeds were planted in the growing medium to determine if controlled drought affects morphology and anatomy of salvia. Polyethylene glycol decreased emergence percentage and delayed emergence up to 5 days. Stem elongation of salvia treated with the five lowest concentrations was reduced up to 35% (21 days after seeding), and salvia were a maximum of 53% shorter and the canopy was 20% more narrow compared to nontreated seedlings 70 days after seeding. These morphological changes were attributed to PEG-8000 mediated reduction in leaf water potential (Ψw). The growing medium Ψw ranged from -0.29 to -0.85 MPa in PEG-8000 treated plants, and plant height was positively correlated with Ψw 21 days after seeding. Stem diameter of PEG-treated seedlings was reduced up to 0.4 mm mainly due to reductions in vascular cross-sectional area. Xylem cross-sectional area decreased more than stem and phloem cross-sectional area. Polyethylene glycol 8000 reduced vessel element number, but not diameter.

Attenuation of cerebral vasospasm by systemic administration of an endothelin-A receptor antagonist, TBC 11251, in a rabbit model of subarachnoid hemorrhage

1997 ◽  
Vol 3 (4) ◽  
pp. E8 ◽  
Author(s):  
John E. Wanebo ◽  
Hunter G. Louis ◽  
Adam S. Arthur ◽  
Jie Zhou ◽  
Neal F. Kassell ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Receptor Antagonist ◽  
Cerebral Vasospasm ◽  
Rabbit Model ◽  
Systemic Administration ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Basilar Arteries ◽  
The Mean

Cerebral vasospasm is a major complication of subarachnoid hemorrhage (SAH) after the rupture of an intracranial aneurysm. Although the cause of cerebral vasospasm has not been fully established, several lines of evidence suggest that the vasoconstrictor peptide endothelin (ET) may play a crucial role. In the present study the potential of TBC 11251 (TBC), a newly developed ETA receptor antagonist, to prevent and/or reverse cerebral vasospasm was examined in a well-established rabbit model of SAH. Sixty-five New Zealand White rabbits were assigned to one of six groups. Experimental SAH was induced in rabbits comprising five of the groups by injecting autologous arterial blood into the cisterna magna. The treatment groups were as follows: 1) control (no SAH); 2) SAH only; 3) SAH + placebo at 24 and 36 hours (24/36); 4) SAH + TBC (24/36); 5) SAH + placebo twice daily (BID); and 6) SAH + TBC BID. All drug-treated animals received an intravenous dosage of 5 mg/kg TBC. After 48 hours, the animals were killed by intracardiac perfusion with fixative. The brainstems were removed and the basilar arteries (BAs) were prepared for histological examination. The cross-sectional area of each BA was measured using computer-assisted videomicroscopy by an investigator blind to the group from which it came. A one-way analysis of variance and paired group mean comparisons with the post-hoc Fisher least significant difference test were used for analysis of BA diameters and physiological parameters. The model provided reliable vasospasm, with the mean BA cross-sectional area constricting from 0.388 mm2 in the control group to 0.106 mm2 (27.4% of control) in the SAH only group. Treatment with TBC (24/36) after SAH (reversal protocol) produced a mean BA area of 0.175 mm2 (44.2% of control) which, although larger than the placebo group value of 0.135 mm2 (39.9% of control), was not statistically significant. However, treatment with TBC BID (prevention protocol) produced a mean BA area of 0.303 mm2 (78.1% of control) compared with the placebo BID value of 0.134 mm2 (34.6% of control); this effect was statistically significant (p < 0.01). There were no side effects noted and no differences in the mean arterial pressures between drug and placebo groups. These findings demonstrate that systemic administration of the ETA receptor antagonist TBC significantly attenuates cerebral vasospasm after SAH when given as a preventative therapy, and they provide additional support for the role of ET in the establishment of vasospasm.

Force deficit during the onset of muscle hypertrophy

1989 ◽  
Vol 67 (6) ◽  
pp. 2600-2607 ◽  
Author(s):  
S. C. Kandarian ◽  
T. P. White
Keyword(s):  
Muscle Mass ◽  
Protein Concentration ◽  
Muscle Hypertrophy ◽  
Structural Changes ◽  
Relative Magnitude ◽  
Interstitial Space ◽  
Cross Sectional Area ◽  
Specific Force ◽  
Sectional Area ◽  
Cross Sectional

The purpose was to study selected structural changes associated with the deficit in maximum specific force (N/cm2) during the early development of skeletal muscle hypertrophy. Ablation of gastrocnemius and plantaris muscles was performed bilaterally in 35-day-old rats (n = 41), and the soleus muscle was studied from days 1 to 30 thereafter. Compared with control muscles from age-matched unoperated rats (n = 48), muscle mass and cross-sectional area increased in parallel from 28 to 52% over the 30-day postoperative period. Specific force of hypertrophied muscle was depressed 38% at days 1 and 3, and by 28% from days 5 to 30 after synergistic muscle ablation compared with age-matched control values. Interstitial space was 38% greater than the control value of 20.4 +/- 1 microliters/100 mg at day 1 only. Protein concentration was depressed 15% for 7 days after the ablation operation, and connective tissue protein concentration was unchanged. The relative magnitude of increased mean fiber cross-sectional area was less than that of muscle mass until day 7 after ablation. Mononuclear cell infiltration in interfascicular spaces occurred from days 3 to 30 without light microscopic evidence of muscle fiber injury. Initial functional deficits are explained in part by an enlarged interstitial space and decreased protein concentration; later deficits are likely accounted for by intracellular changes.

Inhibition of delayed arterial narrowing by the iron-chelating agent deferoxamine

1992 ◽  
Vol 77 (5) ◽  
pp. 763-767 ◽  
Author(s):  
Tsutomu Harada ◽  
Marc R. Mayberg
Keyword(s):  
Protective Effect ◽  
Femoral Artery ◽  
Whole Blood ◽  
Structural Changes ◽  
Morphological Changes ◽  
Platelet Rich Plasma ◽  
Ferric Ion ◽  
Dependent Manner ◽  
Cross Sectional ◽  
Autologous Whole Blood

✓ The potential role of iron in cerebral vasospasm was examined in the rat femoral artery model by the perivascular application of deferoxamine, a ferric ion chelator and antioxidant. In 25 rats, platelet-rich plasma or fresh autologous whole blood containing deferoxamine at concentrations of 1, 5, 10, or 15 mg/ml was applied to the adventitial surface of the femoral artery in a Silastic cuff to insure chronic exposure to the vessel wall. At 7 days, contralateral femoral arteries exposed to whole blood showed a 70% reduction in luminal cross-sectional area and morphological changes associated with vasospasm. Application of platelet-rich plasma or whole blood containing deferoxamine at 25 mg/ml produced no significant arterial narrowing or structural changes; significant intermediate reductions in arterial narrowing were observed at deferoxamine concentrations of 5 and 10 mg/ml. Presaturation deferoxamine (10 mg/ml) with excess ferric ion prior to application eliminated the protective effect. In addition, deferoxamine chelated the ferric ion released from incubated whole blood in vitro over 7 days in a dose-dependent manner consistent with its protective effect in vivo. Ferric ion may influence the development of chronic arterial narrowing after subarachnoid hemorrhage by a variety of mechanisms.

scholarly journals Regional hypoxic cerebral vasodilation facilitated by diameter changes primarily in anterior versus posterior circulation

2016 ◽  
Vol 37 (6) ◽  
pp. 2025-2034 ◽  
Author(s):  
J Mikhail Kellawan ◽  
John W Harrell ◽  
Alejandro Roldan-Alzate ◽  
Oliver Wieben ◽  
William G Schrage
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Vascular Reactivity ◽  
Cerebral Arteries ◽  
Posterior Circulation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Left And Right ◽  
The Right

The inability to quantify cerebral blood flow and changes in macrocirculation cross-sectional area in all brain regions impedes robust insight into hypoxic cerebral blood flow control. We applied four-dimensional flow magnetic resonance imaging to quantify cerebral blood flow (ml • min−1) and cross-sectional area (mm2) simultaneously in 11 arteries. In healthy adults, blood pressure, O2 Saturation (SpO2), and end-tidal CO2 were measured at baseline and steady-state hypoxia (FiO2 = 0.11). We investigated left and right: internal carotid, vertebral, middle, anterior, posterior cerebral arteries, and basilar artery. Hypoxia (SpO2 = 80±2%) increased total cerebral blood flow from 621±38 to 742±50 ml • min−1 ( p < 0.05). Hypoxia increased cerebral blood flow, except in the right posterior cerebral arteries. Hypoxia increased cross-sectional area in the anterior arteries (left and right internal carotid arteries, left and right middle, p < 0.05; left and right anterior p = 0.08) but only the right vertebral artery of the posterior circulation. Nonetheless, relative cerebral blood flow distribution and vascular reactivity (Δ%cerebral blood flow • ΔSpO2−1) were not different between arteries. Collectively, moderate hypoxia: (1) increased cerebral blood flow, but relative distribution remains similar to normoxia, (2) evokes similar vascular reactivity between 11 arteries, and (3) increased cross-sectional area primarily in the anterior arteries. This study provides the first wide-ranging, quantitative, functional and structural data regarding intracranial arteries during hypoxia in humans, highlighting cerebral blood flow regulation of microcirculation and macrocirculation differs between anterior and posterior circulation.

scholarly journals Ultrastructural changes in cristae of lymphoblasts in acute lymphoblastic leukemia parallel alterations in biogenesis markers

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Ritika Singh ◽  
Ayushi Jain ◽  
Jayanth Kumar Palanichamy ◽  
T. C. Nag ◽  
Sameer Bakhshi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
Mitochondrial Biogenesis ◽  
Lymphoblastic Leukemia ◽  
Cross Sectional Area ◽  
Ultrastructural Changes ◽  
Mitochondrial Morphology ◽  
Positive Trend ◽  
Sectional Area ◽  
Cross Sectional

AbstractWe explored the link between mitochondrial biogenesis and mitochondrial morphology using transmission electron microscopy (TEM) in lymphoblasts of pediatric acute lymphoblastic leukemia (ALL) patients and compared these characteristics between tumors and control samples. Gene expression of mitochondrial biogenesis markers was analysed in 23 ALL patients and 18 controls and TEM for morphology analysis was done in 15 ALL patients and 9 healthy controls. The area occupied by mitochondria per cell and the cristae cross-sectional area was observed to be significantly higher in patients than in controls (p-value = 0.0468 and p-value< 0.0001, respectively). The mtDNA copy numbers, TFAM, POLG, and c-myc gene expression were significantly higher in ALL patients than controls (all p-values< 0.01). Gene Expression of PGC-1α was higher in tumor samples. The analysis of the correlation between PGC-1α expression and morphology parameters i.e., both M/C ratio and cristae cross-sectional area revealed a positive trend (r = 0.3, p = 0.1). The increased area occupied by mitochondria and increased cristae area support the occurrence of cristae remodelling in ALL. These changes might reflect alterations in cristae dynamics to support the metabolic state of the cells by forming a more condensed network. Ultrastructural imaging can be useful for affirming changes occurring at a subcellular organellar level.

scholarly journals Correction with thiocetam of lead nanoparticles influence on morpho-functional status of rat liver

2020 ◽  
Vol 33 (3) ◽  
pp. 149-154
Author(s):  
Sergii Omelchuk ◽  
Vasyl Aleksiichuk ◽  
Yuri Chaikovsky ◽  
Liudmyla Sokurenko
Keyword(s):  
Body Weight ◽  
Morphological Changes ◽  
Liver Weight ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Relative Liver Weight ◽  
The Mean ◽  
Pharmacological Correction ◽  
The Cross

AbstractThe aim of this paper is to investigate the influence of Thiocetam on morphological changes in the liver of rats and on biochemical changes in their blood after exposure to lead nanoparticles and compounds. The liver is an organ that performs a number of functions, such as the synthesis of enzymes, hormones, plasma components and the neutralization of toxins. It is involved in many metabolic processes in the body.In undertaking this, colloidal solutions of lead sulphide nanoparticles at dosages 10 nm and 30 nm were injected into two groups of rats, PbSnano1 and PbSnano2, respectively, while group Pb(NO3) received subcutaneously a solution of lead nitrate in ion form in a dose of 1.5 mg/kg (0.94 mg/kg lead, in lead equivalent). After 60 administrations (12 weeks) of the studied substances, the exposure was discontinued and the animals were observed for 18 weeks. Subsequently, half of each group received Thiocetam by injection (for 6 weeks at a dose of 250 mg/kg) while the other half did not. We then assessed the mean body weight, absolute and relative liver weight, blood biochemistry values (total protein, albumin, glucose, total lipids, cholesterol, triglycerides levels in blood serum) and morphological changes in hepatocytes (morphological slides, nuclei cross-sectional area and cytoplasm cross-sectional area).The outcome of this work showed that the mean body weight of animals exposed to nanoparticles with Tiocetam did not differ from that of animals exposed to nanoparticles without pharmacological correction, but relative liver weight was statistically significantly higher than the corresponding values in rats without pharmacological correction. The morphological picture in all study group animals was characterized by the normalization of microvessel blood filling, structure of hepatic plates, disappearance of infiltration with lymphocytes and histiocytes. No dystrophic changes in hepatocytes were found. All this indicates the feasibility of preventive measures during exposure to lead nanoparticles, by administering Thiocetam.In both series of animals exposed to lead nanoparticles (PbSnano1 and PbSnano2), the cross-sectional area of the hepatocytes cytoplasm and the cross-sectional area of the hepatocytes nuclei were smaller than just after exposure, but in the series with Thiocetam adminstration, all the values did not differ from those in the control.

Morphological changes of macular soft drusen and drusenoid DPED after subthreshold micropulse laser treatment

2021 ◽  
Vol 2 (2) ◽  
pp. 95-100
Author(s):  
Qing-Shan Chen ◽  
◽  
Xia Zhao ◽  
Miao-Hong Chen ◽  
Yu-Hang Yang ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Laser Treatment ◽  
Morphological Changes ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Micropulse Laser ◽  
Subthreshold Micropulse Laser ◽  
Soft Drusen ◽  
Baseline Values

AIM: To analyze the morphological changes of macular soft drusen and drusenoid pigmental epithelium detachment (DPED) after subthreshold micropulse laser treatment (SMLT). METHODS: Fourteen patients (20 affected eyes) with soft drusen and DPED clinically confirmed from August 2016 to October 2018, were included in this study. 577 nm yellow laser of SMLT was applied for soft drusen and DPED. The changes of soft drusen and DPED in best corrected visual acuity (BCVA)(LogMAR)and height, diameter and cross-sessional area according to fundus autofluorescence and SD-OCT examinations were observed after SMLT RESULTS: BCVA was not significant difference after treatment of soft drusen (P=0.260), and the DPED (P=0.736) than that of the baseline. Compared with the baseline values, the height and cross-sessional area of soft drusen were reduced at the 6mo after treatment, and the differences were statistically significant (P=0.008, P=0.034). Compared with the baseline values, the differences were not statistically significant in height, diameter and cross-sectional area of DPED after treatment. CONCLUSION: BCVA was not reduced for drusen and DPED after SMLT, however, the height and cross-sessional area of soft drusen was reduced compared with those before treatment, and the differences were not statistically significant in height, diameter and cross-sectional area of DPED before and after treatment. The results indicated that SMLT was effective for soft drusen, but was not effective for short-term treatment of DPED. SMLT caused no damage to the visual acuity in treatment of soft drusen and DPED, but prospective, controlled, large sample and long-term follow-up studies should be required.

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