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At least 163 records · Page 9Linked to original sources

PubMed1992

Antimyeloperoxidase autoantibody-associated necrotizing alveolar capillaritis.

In this report, we describe 3 patients who had pauci-immune necrotizing alveolar capillaritis-related pulmonary hemorrhage and who never developed other organic involvement, as revealed by clinical and laboratory data and also by autopsy examination in 1 case. Serum samples from these patients disclosed antimyeloperoxidase autoantibodies with initial immunofluorescence titers ranging from 1:1,600 to 1:3,200. Rapid institution of immunosuppressive therapy, as well as plasma exchange, led to prompt clinical improvement in 2 patients who were receiving mechanical ventilation support. We conclude that antimyeloperoxidase autoantibodies become new clues to support an underlying alveolar capillary vasculitis in patients with idiopathic isolated pulmonary hemorrhage, thus facilitating therapeutic decisions in this life-threatening condition.

Adult↗

PubMed1999

Effect of weight loss on muscle fiber type, fiber size, capillarity, and succinate dehydrogenase activity in humans.

To examine the effects of weight loss on muscle oxidative properties, nine obese subjects (body mass index, 34 +/- 1.5) had muscle biopsies before and after weight loss and weight stabilization. Weight loss ranged from 13-32 kg and represented 20.8 +/- 2.1% of initial weight. After weight loss, there was no change in the proportions of oxidative (type I and type IIa) fibers and also no change in mean fiber cross-sectional area, whereas there was a small, but significant, decrease in the relative interstitial space (P < 0.05). However, weight loss resulted in a 32 +/- 6% (mean +/- SEM) increase in capillary/fiber ratio and a 54% increase in capillary density (P < 0.05). In addition, there was a 41 +/- 13% increase in succinate dehydrogenase (SDH) activity (P < 0.05). This increase in muscle capillarization and SDH activity was seen in all fiber types, even the relatively lower oxidative type IIx fibers. There was a strong correlation between the change in capillary/fiber ratio and the change in SDH activity (r = 0.82; P < 0.02). Thus, weight loss resulted in no change in muscle fiber type or cross-sectional area, but produced increases in capillary/fiber ratio, capillary density, and SDH activity, suggesting an increase in muscle oxidative capacity.

Adult↗

PubMed1986

Capillarity and mitochondrial distribution in rat myocardium following exercise training.

Rats were subjected to a laddermill running programme either once per week for 6 weeks, or daily for 6 weeks. Heart mass and maximal oxygen consumption rate increased relative to controls and with the frequency of the running programme. Mitochondrial distribution, measured in seven regions within fibres, was similar in all hearts, with a peak volume density of 0.42 +/- 0.01 occurring 4-5 microns from the centre of a capillary. Capillary density decreased with increasing heart mass, but total capillary length and capillary-to-fibre ratio were constant. Thus the higher metabolic demands of the running programmes did not alter the volume density or distribution of mitochondria, despite significant increases in heart mass and decreases in capillarity.

Adenosine Triphosphate↗

PubMed1998

Fiber capillarization and ultrastructure of pigeon pectoralis muscle after cold acclimation.

We investigated the effect of 2 months of exposure to cold conditions (0-5 C) on capillarization and on fiber size, distribution and ultrastructure in the pectoralis muscle of nine pigeons (Columbia livia; mean body mass 700 31 g) and compared the results with measurements from four control birds (mean mass 715 42 g) kept at normal ambient temperature (22-23 C) for the same period. Superficial and deep portions of the muscles, taken from the central area of the right or left pectoralis major muscle, were perfusion-fixed in situ, processed for electron microscopy and analyzed by morphometry. Aerobic fibers represented the vast majority of fibers (93 1 %, mean s.e.m.) in all samples. After cold-acclimation, fiber sectional area was reduced and capillary density increased proportionally. There was no change in the degree of orientation (anisotropy) of capillaries, capillary-to-fiber ratio or fiber type distribution compared with controls. The volume density of mitochondria and lipid droplets in aerobic fibers and capillary diameter increased in response to cold, while the linear relationship between capillary length per fiber volume and fiber mitochondrial volume density remained unchanged. Capillary surface area, intrafiber lipid deposition and fiber mitochondrial volume density were all correlated in cold-acclimated pigeons. The results indicate a close match between the aerobic capacity of the highly aerobic fibers of the pectoralis muscle and their vascularization to meet the increased energetic demand of shivering.

Acclimatization↗

PubMed1989

Pulmonary capillaritis and hemorrhage. A clue to the diagnosis of systemic necrotizing vasculitis.

Patients with systemic necrotizing vasculitis frequently present as diagnostic dilemmas. In previous series of patients with polyarteritis nodosa, less than one third were diagnosed antemortem. Although current clinical awareness of systemic necrotizing vasculitis is greater than in the past and procedures for the diagnosis of these diseases have improved, patients commonly present with atypical features. The diagnosis of a systemic necrotizing vasculitis frequently remains unsuspected or unproven until an involved tissue is biopsied. We report an unusual case of systemic necrotizing vasculitis in which the diagnosis was confirmed by a transbronchial biopsy of the lung which demonstrated pulmonary capillaritis with hemorrhage.

Aged↗

PubMed2003

A glass capillary microelectrode based on capillarity and its application to the detection of L-glutamate release from mouse brain slices.

A new glass capillary microelectrode for L-glutamate is described using pulled glass capillaries (tip size, approximately 12.5 microm) with a very small volume (approximately 2 microl) of inner solution containing glutamate oxidase (GluOx) and ascorbate oxidase. The operation of the electrode is based on capillary action that samples L-glutamate into the inner solution. The enzyme reaction by GluOx generates hydrogen peroxide that is detected at an Os-gel-HRP polymer modified Pt electrode in a three-electrode configuration. The amperometric response behavior of the electrode was characterized in terms of the capillarity, response time, sensitivity and selectivity for measurements of L-glutamate. The currents at 0 V vs. Ag/AgCl increased linearly with the L-glutamate concentration from 10 to 150 microM for in vitro and in situ calibrations. The response was highly selective to L-glutamate over ascorbate, dopamine, serotonin and other amino acids. The detection of L-glutamate in the extracellular fluids of different regions of mouse hippocampal slices under stimulation of KCl was demonstrated.

Animals↗

PubMed2003

Vascular endothelial growth factor, capillarization, and function of the rat plantaris muscle at the onset of hypertrophy.

Capillary proliferation occurs during compensatory hypertrophy. We investigated whether the expression of vascular endothelial growth factor (VEGF) is elevated at the onset of hypertrophy when capillary proliferation is minimal, and whether muscle damage as assessed by muscle force deficits, may occur at the onset of hypertrophy. To investigate this, we induced in 9-month-old rats, under isoflurane anesthesia, hypertrophy of the left plantaris muscle by denervation of the gastrocnemius and soleus muscles. Capillarization was investigated in both the deep (oxidative) and the superficial (glycolytic) regions of the plantaris muscle. After 2 weeks, muscle mass had increased by 16% (p< 0.01), which was not accompanied by increases in fiber size. The maximal tetanic force (P(0)) and specific tension (P(0).g(-1) or P(0).cm(2)) and twitch characteristics were unaltered, and fatigue resistance of the overloaded muscle was improved (p< 0.05). However, the myosin heavy chain composition was unaltered. Capillary proliferation was not yet evident, but VEGF mRNA and protein levels were elevated 1.5- and 8-fold, respectively (p< 0.05). We concluded that the normal specific tension and the elevated VEGF expression after 2 weeks of overload indicate (1) an absence of or minimal muscle damage at this early time point, and (2) that elevated VEGF expression precedes and is involved in capillary proliferation that occurs during the later stages of compensatory hypertrophy.

Animals↗

PubMed1991

Essential fatty acid diet supplementation. Effects on peripheral nerve and skeletal muscle function and capillarization in streptozocin-induced diabetic rats.

Effects of essential fatty acids on nerve conduction, hypoxic resistance, skeletal muscle contractile properties, and capillary density were examined in streptozocin-induced diabetic rats. Nondiabetic and diabetic controls and three diabetic groups treated with 10% supplements of corn oil, evening primrose oil (Efamol), or a mixture of 80% evening primrose oil and 20% fish oil (Efamol Marine) for 2 mo were used. Efamol and Efamol Marine increased plasma gamma-linolenic acid levels, but arachidonic acid was elevated only with Efamol. Diabetes resulted in 15-29% reductions in sciatic motor and sensory saphenous nerve conduction velocity. Efamol prevented conduction deficits more effectively than Efamol Marine, and corn oil had no effect. In vitro measurement of sciatic nerve hypoxic resistance revealed a 49% increase in the time taken for action potential amplitude to decline by 50% with diabetes. Corn oil had no significant effect. With Efamol, hypoxic resistance was within the nondiabetic range. Efamol Marine produced intermediate results. Functional improvements may relate to enhanced vasa nervorum perfusion, because endoneurial capillary density increased by 22% with Efamol, angiogenesis perhaps resulting from eicosanoid production from arachidonic acid. Soleus muscle contractions were prolonged by diabetes. This was partially corrected by treatment, Efamol being most effective. Extensor digitorum longus muscle had reduced tetanic tension with diabetes, and this was prevented by all treatments. Soleus showed a modest increase in capillarization with Efamol, which may have contributed to reduced susceptibility to fatigue. The data suggest involvement of abnormal fatty acid metabolism in the etiology of diabetic neuropathy and myopathy.

Animals↗

PubMed1996

Relationship between fiber capillarization and mitochondrial volume density in control and trained rat soleus and plantaris muscles.

OBJECTIVE: The majority of investigations have demonstrated a strong relationship between muscle capillarity and oxidative capacity. There is, however, evidence that the capacities for O2 supply and utilization can be dissociated. Also, metabolite removal rather than O2 supply may represent the predominant design constraint placed on the capillary bed in some muscles (i.e, fast-twitch glycolytic). Recent evidence suggests that the principal barrier to O2 diffusion in skeletal muscle resides between the red blood cell and the immediately subjacent sarcolemmal space. Consequently, if the primary design constraint placed on the capillary bed is to facilitate O2 exchange, we hypothesized that capillary surface per fiber surface should be correlated with the mitochondrial volume subserved. Thus, the purpose of this study was to investigate whether one single relationship would be found between the capillary-to-fiber surface ratio and fiber mitochondrial volume in slow- (soleus) and fast-twitch (plantaris) muscle and whether this relationship would be preserved after training. METHODS: Rats were exercise-trained on a motor-driven treadmill up to 60 min/day, 5 days/week for 4 weeks at an intensity calculated to elicit congruent to 75% VO2max. Following training, soleus (S) and plantaris (P) muscles were removed under deep anesthesia for citrate synthase analysis, and the contralateral limb was perfusion-fixed in situ with glutaraldehyde and analyzed morphometrically under light and electron microscopy. RESULTS: Training significantly (p < 0.05) increased citrate synthase activity and capillary-to-fiber ratio both in S and P muscles. For all muscles combined (i.e., S and P, control and trained), the capillary-to-fiber surface ratio significantly correlated with mitochondrial volume per unit fiber length (r = 0.64). CONCLUSIONS: Our finding of a single relationship between the capillary-to-fiber surface ratio and fiber mitochondrial volume across the muscles is consistent with the notion that the size of the capillary bed in muscles comprised principally of either slow-twitch oxidative or mixed fast-twitch oxidative glycolytic and fast-twitch glycolytic fibers is primarily designed to meet fiber requirements for O2 exchange, and that an important site for O2 diffusion resistance is at the capillary-fiber interface. In addition, capillary-to-fiber surface and fiber mitochondrial volume increased in similar proportions, i.e., the relationship between the two variables was preserved after endurance training.

Animals↗

PubMedDate not supplied

Cytology by capillarity and anatomopathological diagnosis of solid breast tumors.

A study was conducted on material obtained by capillarity puncture (74 punctures) from 71 patients with breast tumors. The material was fixed in absolute alcohol and stained by the Papanicolaou method and the result was classified as insufficient material, or as negative, suspect or positive cytology. After tumor exeresis, the anatomopathological results of each patient were compared to the cytology data. A single false-positive case was obtained among 44 patients (97% specificity) and 9 false-negative cases were obtained among 16 patients (56% sensitivity).

Adult↗

PubMed1991

Capillarization of the hypertrophic heart: discrepancy of the results obtained by the triangulation and domain methods.

The geometry of capillary networks was examined in pressure-overloaded hypertrophic rat myocardium. All hearts were exposed to a staining protocol that distinguished the arteriolar (AC) and venular (VC) regions of capillaries. In control hearts, the triangulation method (one-dimensional distance between neighboring capillaries) and the domain method (two-dimensional area surrounding capillaries) exhibited similar results, showing increased capillarization for the venular region of capillaries networks. In hypertrophic hearts, the triangulation method did not demonstrate differences between arteriolar and venular capillaries (AC = 27.2 +/- 0.4 microns, VC = 27.0 +/- 0.2 microns, p = 0.56). However, the domain method still detected smaller tissue supply regions for venular capillaries (AC = 547 +/- 6 microns 2, VC = 464 +/- 5 microns 2, p less than 0.01). To resolve this discrepancy in hypertrophic heart, we have measured capillary spacing from longitudinal sections at discrete intervals along the A-V path length. These results indicate a stepwise decrease in intercapillary distance from arteriole to venule for both groups, which would support results obtained by the domain method. A possible explanation for the discrepancy between these two methods, specific to hypertrophic heart, may be changes in the clustering patterns of arteriolar and venular capillaries.

Animals↗

PubMed1986

Role of hemoglobin and capillarization for oxygen delivery and extraction in muscular exercise.

Through the years the role of the various links in the transport of oxygen in the human body has been discussed extensively, and especially whether one of these links could be singled out as limiting oxygen uptake during exercise. In his thesis work Lars Hermansen dealt with several of these variables related to oxygen transport and uptake. Two of these were the hemoglobin concentration of the blood (Hb) and skeletal muscle capillarization. These are the focus of this article. It can be demonstrated that variation in arterial oxygen content due to different Hb concentrations is fully compensated for at the level of the muscle, i.e. the amount of oxygen delivered to contracting muscles is adjusted by a variation in the blood flow so that it is the same regardless of Hb concentration in the range of 118-172 g X l-1. At the systemic level, with a large fraction of the muscle exercising, this causes an increase in submaximal heart rate and a lowering in maximal oxygen uptake in people with low as compared to normal or high Hb concentration. The primary significance of an enlarged capillary network in the muscle does not appear to be for accommodating a larger flow, but rather to allow for a long enough mean transit time and large enough surface area for optimal exchange of gases, substrates and metabolites.

Capillaries↗

PubMed1986

Time dependence of dipyridamole-induced increase in skeletal muscle capillarization.

40 young Sprague-Dawley rats in groups of 10 were subjected to treatment with dipyridamole for 1, 2, 4 and 8 weeks. Another 40 sham-treated rats served as controls. The medial portion of the quadriceps femoris muscle was evaluated for total capillarization, fiber area and fiber type composition. Capillary/fiber ratio and mean number of capillaries in contact with each fiber were significantly increased in the rats treated with dipyridamole for 2 weeks and longer. The capillary density, however, did not increase until after 4 weeks of dipyridamole treatment. The fiber area increased gradually with age and was significantly enlarged by dipyridamole treatment after 2 and 4 weeks. All fibers in the examined muscles were of the low oxidative (white) type and no change was recorded in this respect after dipyridamole treatment.

Animals↗

PubMed1985

Analysis of skeletal muscle capillarization: methodological problems.

Capillarization of skeletal muscle has been studied on the same muscle with different methods. Capillary/muscle fibre ratio, number of muscle fibres in contact with capillaries, capillary density in a unit area, capillary density on the muscle fibre surface were determined. The various methods gave different numerical data. Determination of capillary/muscle fibre ratio seemed to be the most reliable index of the changes in pathological conditions.

Animals↗

PubMed1979

[Haemangioma capillare of the pleura with ipsilateral haemopneumothorax (author's transl)].

1. The article introduces a patient with left-side haemangioma capillare of the pleura parietalis with haemopneumothorax and ipsilateral cystic changes of the left upper lobe of the l,ng. 2. The aetiopathogenesis of the disease is discussed as an abortive type of Rendu-Osler-Weber disease (hereditary haemorrhagic telangiectasia), the diagnosis being based exclusively on histological findings as the only possibility of diagnosis. 3. The therapeutic approach is discussed.

Adult↗

PubMedDate not supplied

[Nosology of so-called capillaritis ulcers].

It was with ochre dermatitis that the clinical notion of "capillaritis" was first put forward, but in what sense is it still possible today to speak of "capillaritic ulcer"? Although some special characteristics have been ascribed to it, this ulcer is derived from a microvascular and tissue reaction to venous stasis, whether the latter is primary due to varicose veins or secondary due to "post-thrombotic syndrome" or obliterative arteriopathy of the supplying trunks and especially the nutritional branches of the dermohypodermic network. This type of ulcer involves the Circulatory Unit and is expressed by an imbalance in irrigation, the result of a whole sequence of capillary closures and anastomotic openings, of which the "mosaic" appearance on infra-red thermography is evidence. It is a stasis ulcer in which the mode of distribution of the capillaries is involved just as much as the thickness of the skin of the groove of Bisgaard, but it is the result of the majority of the angiopathic states of the lower limb.

Capillaries↗

PubMed1983

Cytochemical localization of lipases during spore germination from Bryum capillare.

In the oil containing spores of Bryum capillare, lipid breakdown occurs within three days after sowing. The periods of activity of acid, neutral and alkaline lipases are coincident. They start at the first day after sowing the spores. After 3 days of germination, when storage fats forming large globules are mobilised no lipase activity could be detected any longer in the glyoxysomes. Acid lipase is preferentially located in spherosomal membrane but is also present at the glyoxysomal membrane. Alkaline lipase is specifically located in the glyoxysomes and mitochondria. A cooperation presumably exists between acid and alkaline lipases in the hydrolysis of monoglycerides at the glyoxysomal level. Neutral lipase activity is localized at the spherosomal membrane, in the endoplasmic reticulum and in dictyosomes. It is absent from glyoxysomes.

Histocytochemistry↗

PubMed1995

Pulmonary capillaritis and alveolar hemorrhage associated with the antiphospholipid antibody syndrome.

Pulmonary hemorrhage due to small vessel vasculitis is a well recognized complication of many autoimmune and collagen vascular disorders. The antiphospholipid antibody syndrome (APS) is a disorder associated with hypercoagulability, thrombocytopenia, and thromboembolic phenomena. Pulmonary manifestations include pulmonary embolism, pulmonary hypertension, and respiratory failure associated with diffuse pulmonary infiltrates. We describe a patient with the APS syndrome, without systemic lupus erythematosus, who developed pulmonary hemorrhage due to pulmonary capillaritis with evidence of perivascular immune complex deposition.

Antigen-Antibody Complex↗