The relationship between interleukin-13 and angiogenin in patients with bladder cancer

Participation of anti-inflammatory interleukin-13 (IL-13) in the process of carcinogenesis was well studied. Angiogenesis plays a key role in the process of tumour growth and metastasis. Higher expression of angiogenin (ANG) have been proven in many types of cancers. The aim of the study was to more fully understand the significance of plasma IL-13 as an immunomodulator and ANG as a stimulator of the angiogenesis process in patients with bladder cancer (BC) and to investigate the relationship between parameters. These parameters were examined in the group of BC patients and in subgroups of BC depending on clinical stage: non-muscle invasive bladder cancer (NMIBC), muscle invasive bladder cancer (MIBC), histopathologic malignancy low grade (LG), high grade (HG) and in primary and recurrent BC. The level of IL-13 and ANG in the plasma of BC patients and controls were measured by enzyme-linked immunosorbent assay. All calculations were done using the STATISTICA 13.3 (TIBCO software Inc.). Plasma levels of IL-13 and ANG were significantly higher in BC patients and in all patient subgroups examined than in the controls (p < 0.001). A negative significant correlation was found between ANG and IL-13 levels in BC-patients. Based on the receiver operating characteristic curves (ROC), IL-13 had good diagnostic value in BC. The presented results may suggest a relationship between angiogenesis and inflammation in the pathogenesis of bladder cancer and the development of this disease. With the increase of IL-13 level in BC-patients plasma, the ANG level decreased.

Clinical variables improve efficacy of ECG scores to diagnose the left ventricular hypertrophy in general population

 

Left ventricular hypertrophy (LVH) is an important risk factor of various cardiovascular (CV) diseases and sudden death. Electrocardiography (ECG) is commonly used to detect LVH, but it has poor sensitivity, especially in high cardiovascular risk patients. Although echocardiography (ECHO) is a better, it is less available, and more expensive. Aim: To improve ECG scores to diagnose LVH in a general population.

Methods

The study was conducted in 2017–2019 in a representative sample of area residents. 717 volunteers randomly chosen from the local population were examined. Due to incomplete data, QRS complex duration ≥120ms, fascicular blocks, bundle branch blocks, paced rhythm, 216 people were excluded. Physical examination, ECG, ECHO and laboratory assessment were performed. In ECG LVH defined as &gt;28mm for men, &gt;20mm for women using Cornell index; &gt;17mm for both sexes using Lewis index. In ECHO LV mass was calculated using the Devereux Formula and indexed by body surface area (left ventricular mass index – LVMI). The LVH was defined as LVMI ≥115 g/m2 for man and ≥95 g/m2 for women. Cardiovascular risk was calculated based on the ESC SCORE and additional risk categories published in the latest ESC guidelines. We analyzed 4 models to predict the probability of LVH at ECHO: Model 1: Cornell index; Model 2: Lewis index; Model 3: Cornel index + clinical parameters (age, sex, BMI, office BPs, QRS time, hs-TnT, and HbA1c); Model 4: Lewis index + clinical parameters (age, sex, BMI, office BPs, QRS time, hs-TnT, and HbA1c). Associations between LVH and clinical and biochemical variables were earlier analyzed using multiple linear regression models, these parameters were independently associated with LVH.

Results

A total of 501 patients were included. The average age of patients was 49.0±15.35 years, and 203 probants (40.5%) were male. We developed a novel score to assess the probability of LVH at ECHO in general population based on nine items (age, sex, body mass index, office BPs, Cornell index or Lewis index, QRS time, hs-TnT, and HbA1c). Additional clinical parameters improved sensitivity of Cornell index up to 86.0% (AUC:0.8011; 95% CI:0.748–0.854) from 64.9% (AUC:0.6450; 95% CI:0.573–0.716) in general population, to 92.9% (AUC:0.8423; 95% CI:0.760–0.924) from 64.3% (AUC:0.6481; 95% CI:0.518–0.779) in low CV risk patients, to 69.2% (AUC:0.6767; 95% CI:0.544–0.809) from 38.5% (AUC:0.5284; 95% CI:0.352–0.705) in moderate CV risk, and to 73.3% (AUC:0.7151; 95% CI: 0.609–0.821) of Lewis index from 50.0% (AUC: 0.5630; 95% CI:0.448–0.678) in high and very-high CV risk class.

Conclusions

Addition of clinical parameters to ECG indices in the diagnosis of LVH markedly improves their diagnostic efficacy both in general population and in higher risk groups. The new score may be useful in guiding the appropriateness of ECHO study in general population, and especially in moderate and high CV risk patients, who are not always aware of the increased CV risk.

ROC curves for recognize LVH.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Medical University of Bialystok for Bialystok PLUS study

Chemerin in coronary artery disease patients

Background

Chemerin – a recently described hormone is secreted by adipose tissue. It exerts proinflammatory action, leads to insulin resistance, but also has potentially favorable effects: it increases eNOS activity and is pro-angiogenic. Increased serum concentrations of chemerin was observed in patients with coronary artery disease (CAD). The role of chemerin in pathogenesis of CAD is not well understood.

Purpose

The aim of this pilot study was to assess the role of chemerin in pathogenesis of atherosclerosis, its impact on condition of large arteries and prognosis in CAD.

Methods

We included in the study patients with stable CAD who underwent percutaneous coronary intervention (PCI) in the past. Chemerin levels were measured with ELISA method. All patients had routine blood tests and insulin levels measured. Patients without history of diabetes also had OGTT. Status of large arteries was evaluated with carotid ultrasound, pulse-wave velocity (PWV) and ankle-brachial index (ABI). Body composition was assessed wit DEXA method. Anatomical severity of CAD was evaluated with SYNTAX score. One-year composite endpoint included death, myocardial infarction, revascularization, stroke and hospitalization for cardiovascular reasons.

Results

The study group comprised 163 patients (mean age 59.8± years, 26% of females, n=43). Mean chemerin level was 284.8 ng/ml. There was no significant difference in chemerin concentrations between patients with diabetes and remaining ones (with prediabetes and with normal glucose levels) 306.8±121 vs 274.15±109 pg/ml, p=0.1. In Spearman test chemerin level correlated with total fat mass (R=0.15, p=0.047), trunk fat mass (R=0.16, p=0.039), android fat mass (R=0.16, p=0.036), and BMI (R=0.18, p=0.028). Chemerin also correlated with white blood cells (WBC) count (R=0.34, p&lt;0.0001), hsCRP (R=0.16, p=0.03), total cholesterol (R=0.17, p=0.028), LDL cholesterol (R=0.19, p=0.01), HDL cholesterol (R=−0.21, p=0.006), triglicerides (R=0.3, p&lt;0.0001), platelet count (R=0.23, p=0.002), fasting insulin (R=0.22, p=0.004) and c-peptide (R=0.26, p=0.0005). There was no significant difference in chemerin levels between patients with carotid atherosclerosis (n=93) and patients with normal carotid arteries (n=70), (300±124 vs 263±94 ng/ml, p=0.07). There were no significant associations between chemerin levels and PWV, ABI measurements, SYNTAX score, or 1-year prognosis.

Conclusions

This is the first study to show that in patients with CAD chemerin levels correlate with WBC and with android fat tissue mass. Additionally, chemerin levels positively correlated with other inflammation or insulin resistance markers, and with unfavourable lipid profile.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The National Science Centre

The Influence of Polyphenol Compounds on Human Gastrointestinal Tract Microbiota

Polyphenols form a diverse group of compounds containing at least two hydroxyl groups in their chemical structure. Because of the common presence in plant kingdom, polyphenols are considered a significant component of food and an important group of compounds with antioxidant properties. The absorption of polyphenols present in food depends mostly on the activity of intestinal microflora. However, little is known about the processes and interactions responsible for such phenomenon in guts ecosystem. There are only few available publications that examine the effect on polyphenols on intestinal microbiota. Therefore, this work will focus on describing the relationship between polyphenol compounds present in food and bacteria colonizing the intestines, their mechanism, and impact on human’s health.

P4369Direct comparison of prognostic value of echocardiographic parameters of right ventricular dysfunction in normotensive patients with acute pulmonary embolism

Background

Although various echocardiographic parameters of right ventricular dysfunction (RVD) were reported to be of prognostic value in normotensive patients with acute pulmonary embolism (APE), an optimal definition of RVD on echocardiography is missing.

Purpose

We performed a direct comparison of prognostic value of RV/LV ratio, TAPSE, and TRPG/TAPSE for complicated clinical course that included: in-hospital APE related mortality, hemodynamic collapse or rescue thrombolysis.

Methods

Prospective cohorts of APE patients normotensive at admission, managed according to the ESC Guidelines 2014 were merged in a collaborative database. Transthoracic echocardiography was performed at admission, as soon as possible. All studied parameters were available in each patient. AUC in ROC analysis were assessed for each parameter and were compared between them. Multivariable Cox regression analysis was performed to assess the combination of echo-parameters.

Results

Overall, 490 pts were included in the study (229F), aged 64±18 years. Clinical endpoint occurred in 31 pts including 8 APE related deaths. AUC for SAE of RV/LV, TAPSE and TRPG/TAPSE were similar (Figure 1). TAPSE <16mm compared to other echo-parameters showed the highest PPV and NPV (Table 1). Cox regression analysis including SBP, HR, age, elevated troponin and echo-parameters showed that only blood pressure, RV/LV >1 and TAPSE <16mm were identified as independent predictors of outcome (HR 0.98 (95% CI: 0.96–0.99), p=0.03; 2,53 (95% CI: 1.2–5.7), p<0.03 and 3,76 (95% CI: 1.74–8.11), p<0.001).

Table 1. Predictive values of proposed cut offs of echocardiographic parameters Parameter Sensitivity Specificity PPV NPV TAPSE <16mm 52% 85% 18% 96% RV/LV >1.0 74% 63% 12% 95% TAPSE<20 & TRPG/TAPSE >4.5 10% 94% 10% 94%

Figure 1

Conclusions

Although all TAPSE, RV/LV ratio and TRPG/TAPSE showed similar performance for prognosticating of in-hospital outcome in normotensive PE patients, TAPSE<16mm showed the highest predictive value for identification of patients at risk of complicated clinical course.

The impact of metalloestrogens on the physiology of male reproductive health as a current problem of the XXI century

In the XXI^st century in highly developed countries, progressively decreasing male reproductive potential is indicated. In recent years epidemiological studies indicate the deterioration of semen parameters: reduction of ejaculate volume, sperm count, and mobility, as well as abnormalities in their morphology. Male infertility can result from many different agents, such as: anatomical or genetic abnormalities, systemic or neurological diseases, infections, trauma, iatrogenic injury, gonadotoxins and development of sperm antibodies and lifestyle (especially obesity, heat and tobacco smoking). It is well documented that adverse changes in male fertility also seem to be associated with environmental exposure to different substances, especially endocrine active factors, known as xenoestrogens, and among these metal ions, known as metalloestrogens, are very important. The role of some metalloestrogens in various diseases, both in women and men, is known and particularly well-proven in women, but still little is known about their role in the regulation of male reproductive potential. Thus we decided to analyse the available information exploring this problem. The review was carried out using the Medline and Google Scholar databases, using the keywords: xenoestrogens, metalloestrogens, male fertility, semen quality, male reproductive potential, mechanisms of metalloestrogen action, environmental pollution and the name of the particular metal. Articles published between 2000 - 2019 have been taken into account, including human and vertebrate animal studies and cell lines. The aim of this review is to discuss the role and mechanisms of action of fifteen metalloestrogens in the human organism, as well as in animal models, and cell cultures, paying special attention to their influence on the physiology of male reproductive health, according to the current state of knowledge. The role of certain metals in human reproduction is still poorly investigated and for some of them only single studies are available. Many factors in our daily lives have a significant impact on male fertility, therefore education is necessary on the threats and how they may be eliminated as far as possible.

Styrene and ethylene glycol have a synergetic effect on lipid peroxidation that is better protected than repaired by CoQ10

Previous study of a group of 22 workers occupationally exposed to styrene, ethylene glycol and their mixture at a paint and lacquer industry indicated significantly elevated concentration of malondialdehyde with 4-hydroxynonenal (MDA+4-HNE) in the blood plasma, successfully decreased with coenzyme Q10 (CoQ10) supplementation. The aim of present study is to evaluate whether the exposure to styrene or/and ethylene glycol could be responsible for the increase in MDA level. The mechanism of a single solvent action and the mixture was examined, specially whether it is connected with hydroxyl radical (*OH) generation. It was also investigated whether coenzyme Q10 could be considered as a protective (given before the solvents) or repairing (given after the solvents) agent in oxidative stress caused by the solvents. The results indicate that ethylene glycol nor styrene increase MDA and *OH, but as a mixture give synergetic interaction, elevating MDA and *OH concentration to a statistically significant extent. Coenzyme Q10 at a dose of 3.0 microg/ml only protects, but does not repair increased lipid peroxidation caused by ethylene glycol with styrene. In order to obtain both a protective and repairing effect, a concentration of 12.0 microg/ml CoQ is needed.

Oxidative stress and coenzyme Q10supplementation in renal transplant recipients

Recently some reports about the oxidative stress in renal transplant recipients have been published. The role of coenzyme Q10 (CoQ10) as radical scavanger is largely known. The aim of our study was to evaluate the protective role of CoQ10 in renal transplant recipients on lipid peroxidation and lipids parameters, as well as its influence on antioxidant enzymes, neutrophils chemiluminescence and urinary enzymes. The study was performed in 11 long term allograft recipients treated additionally with CoQ10 90 mg/day in three doses, 30 mg each for four weeks. The malonyldialdehyde (MDA) and 4-hydroxynonenal (4-HNE), superoxide dismutase (SOD) and glutathione peroxidase (GPx) and the basic parameters of lipid metabolism such as total cholesterol (TC), high and low density lipoproteins (HDL, LDL), triglycerides (TG), atherogenicity indicators [LDL/HDL; (TC-HDL)/HDL] were evaluated. The chemiluminescence of neutrophils (luminol, fLMP-method) were mesured and the activity of N-acetyl-beta-D-glucosaminidase (NAG), alanylaminopeptidase (AAP), elastase, alpha-1-antitrypsin. All parameters were estimated before and after CoQ10 treatment. Statistically significant changes were noticed with the LDL and atherogenicity indicators (p < 0.01) (decrease) as well as HDL level (p < 0.001) (increase). Also the significant decrease of fMLP stimulated PMNL chemiluminescence (p < 0.05) confirms the antioxidative properties of CoQ10. The significant increase of NAG activity (p < 0.05) can't be the result of nephrotoxic effect, because NAG-B is unchanged. Serum concentration of creatinine and cyclosporine A in renal allograft recipients was unchanged after CoQ10 treatment. The presented date shows that further study with CoQ10 treatment in renal transplant in larger numbers and over longer periods should be considered.

[Congenital jejunoileal and colonic atresia]

Jejunoileal and colonic atresias are a common cause of neonatal intestinal obstruction. Authors present the aetiology, types of atresias, clinical symptoms, diagnostics, surgical treatment, problems of postoperative management and prognosis in the newborns with congenital intestinal atresia. In the years 1992-2000, in the Department of Paediatric Surgery and in the Department of Pathology and Intensive Care of Newborn at the National Research Institute of Mother and Child in Warsaw, 539 newborns were surgically treated (congenital anomalies of gastrointestinal tract, genito-urinary system, central nervous system, defects of abdominal wall and diaphragm). In 21 patients jejunoileal or colonic atresia were confirmed. On the base of the course of treatment the authors analyse prognostic factors: prematurity, certain types of atresia, additional pathology accompanying intestinal defect, necessesity of re-section of the long part of the bowel or multiple anastomosis. Diagnostic and treatment problems in three patients with short bowel syndrome needed additional discussion.

[Advances in treatment of congenital gastroschisis based on personal examinations]

The aim of the study was the definition of standard approach to a newborn with gastroschisis. The rules of treatment introduced in 1992 enabled the closure of the abdominal wall primarily in all newborns and made it possible to decrease the mortality considerably. This was achieved despite the fact that we usually did not have influence on time and method of delivery or quality of transportation to our department. In the Department of Pediatric Surgery of Institute Mother and Child, in the years 1992-1997, twenty three newborns with gastroschisis were admitted. The standard approach in all patients was the following: insertion of the catheters to the small bowel through the appenddicocaecostomy and to the large bowel through the rectum, intraoperative irrigation of the meconium (mucosolvan), forceful stretching of the abdominal wall, returning of extraabdominal viscera under control of central venous pressure or middle airway pressure (anesthesiologic control). In the postoperative period all patients routinely had controlled ventilation, administration of analgesic drugs, catecholamines, antibiotics and total parenteral nutrition. Intestinal catheters were gradually removed every day for irrigations of all levels. Oral nutrition was started after the return of effective peristalsis. From 23 treated newborns 16 are alive. 7 children died, 4 of them were resuscitated before operation because of severe general condition. Two patients died because of sepsis in the second month of life, one because of SIDS (sudden infant death syndrome) in the third week of life. Sixteen children are followed up. The development of all children is normal.

Enzymuria in antibiotic therapy of acute infections

Activities of N-acetyl-beta-D-glucosaminidase (NAG), its isoenzyme NAG-B, alanylaminopeptidase (AAP), elastase and trypsin inhibitor (alpha 1 PI) were evaluated as markers of nephrotoxicity and inflammation in acute infections treated with various antibiotics (vancomycin, netilmicin, pefloxacine, cefoperazone and imipenem).

[Preoperative diagnosis and surgical treatment tactics for anorectal malformations in light of personal observations]

The article presents contemporary views on classification, diagnostics and surgical treatment of congenital anorectal anomalies. The model of one stage or multi stage repair depending on the kind of defect and the necessity the anal sphincter muscles reconstruction was discussed. It was noticed that the most important independent factor which can have influence on the functional outcome is a normally developed sacral bone. The objective method of evaluation of the sacrum proposed by Schneider Hospital in New York is presented.

Listeria meningitis presenting in an immunocompetent adult patient

A case of fatal Listeria meningitis in an immunocompetent 39-year-old female is presented. Although most patients with CNS listeriosis are immunosuppressed, infection in immunocompetent individuals may also occur.

The chemoprotective effect of coenzyme Q on lipids in the paint and lacquer industry workers

The influence of coenzyme Q on the lipid parameters in the paint and lacquer industry workers is presented. The examinations were carried out in the group of 24 workers employed at the paint and lacquer production, who received coenzyme Q10 as a chemoprotective agent. Serum concentration of basic lipid parameters: total cholesterol (TC), high density lipoproteins (HDL), low density lipoproteins (LDL), triglycerides (TG); lipid peroxidation products: malonyldialdehyde (MDA) together with 4-hydroxynonenal (4-HNE) and two antioxidant enzymes: superoxide dismutase (SOD) and glutathione peroxidase (GPx) were examined. The above parameters were measured in workers exposed to organic solvents and then after 4 weeks of coenzyme Q treatment. In order to explain, whether the occupational exposure is responsible for the changed level of some parameters, the reference group, not employed in the paint and lacquer industry, was used. The results indicated that the preliminary blood serum concentration of MDA + 4-HNE in workers exposed to organic solvents was significantly elevated in comparison to the control group. Statistically significant decrease in MDA + 4HNE concentration was observed after coenzyme Q treatment what lead to the conclusion that coenzyme Q could be considered as a protective agent against lipid peroxidation in occupational exposure. The changes in other parameters were statistically insignificant.

Muscular fatigability in mitochondrial myopathies. An electrophysiological study

A frequent occurrence of ophthalmoplegia and muscle fatigability in mitochondrial myopathy (MAM) often makes its differential diagnosis from myasthenia rather difficult. Neuromuscular transmission was investigated in 9 patients with MAM, presenting marked fatigability. The aim of the study was to see whether there were any other causes of muscle fatigability in addition to the metabolic factors. Classical electrostimulation as well as the SFEMG, which is very sensitive in detecting neuromuscular transmission disorders, were used. The findings were far from uniform: we found normal neuromuscular transmission in 5 cases, in 3 patients we observed slight abnormalities of neuromuscular transmission, in 1 case neuromuscular transmission disturbances seemed to be of neurogenic origin. Our results allow an assumption that the causes of muscle fatigability in MAM are of a much more complex nature than it has been anticipated. They might depend not only on the metabolic disorders within the muscle fibre itself but also on the impaired function of the peripheral nerve or of the neuromuscular junction. All the mechanisms combined may also play a role, though in individual patients the contribution of particular factors responsible may vary.

[Atypical clinical image of myopathy with abnormal mitochondria (MAM) in our cases]

Two peculiar cases of mitochondrial myopathy are presented. In the first case the diagnostic difficulties are discussed stressing especially the differentiation of the myopathy from myasthenia. In the second cases polyneuropathy signs were evident, which is extremely rare in this myopathy.

[Comparative studies of cyclic 11, 12 erythromycin carbonate (davercin) and erythromycin a levels in lung tissue, serum and bronchial secretions]

A comparison of serum, pulmonary tissue and bronchial secretory levels of erythromycin and cyclic--11,12 carbonate of erythromycin (Davercin--Polfa) was carried out in 55 patients with lung cancer. All patients received erythromycin and Davercin 80 hours prior surgery, during which a small fragment of pulmonary tissue was removed for further evaluation. Concentration of both antibiotics was determined microbiologically. Better penetration of Davercin to the pulmonary tissue was found, as well as higher tissue concentration. The study demonstrates the advantage of Davercin over erythromycin in treating bacterial infections of the respiratory system.

Progressive supranuclear palsy with lower motor neuron involvement. A case report

The clinical picture of progressive supranuclear palsy is relatively constant, including supranuclear ophthalmoplegia, pseudobulbar palsy, axial dystonia in extension, parkinsonian signs, postural instability and dementia. A case is reported, which is unusual in having flexor dystonia of the neck and marked signs of lower motor neuron involvement.

Primary systemic carnitine deficiency under successful therapy: clinical, biochemical, ultrahistochemical and renal clearance studies

Systemic carnitine deficiency is an often fatal, but treatable metabolic disorder which should be considered in any child with repeated episodes of a Reye-like syndrome or a cardiomyopathy. A 4-year-old girl with a typical history and clinical findings was successfully treated with oral carnitine. Despite low liver carnitine, ketogenesis upon fasting was normal. Normal muscle function under therapy was associated with unchanged low muscle carnitine levels. Improvement of mitochondrial structure and function was demonstrated by controlled ultrahistochemical studies. A renal carnitine leak, evident from renal clearance studies, may contribute to the pathogenesis of systemic carnitine deficiency.

[Syndrome of amyotrophic lateral sclerosis after thymectomy performed for myasthenic syndrome]

A case of amyotrophic lateral sclerosis was observed developing three months after thymectomy in a woman aged 52 years. The patient had been referred for thymectomy because of myasthenic signs increasing in intensity since 2 years. Myasthenia was confirmed by electrophysiological investigations, and the diagnosis was: myasthenic syndrome and suspected thymoma. During nearly 5 years of follow-up the following observations were made: there was a correlation between thymectomy and the development of ALS syndrome, thymosine administration produced clinical improvement, thymosine administration improved the function of thymus-dependent lymphocytes, thymosine withdrawal (due to non-availability) produced exacerbation of symptoms.

Spinal cord damage as a complication of renal artery embolization in patients with renal carcinoma

The authors report three cases of complications of renal artery embolization in patients with renal carcinoma. In two cases renal artery embolization was followed by paraparesis with loss of sphincter control. In these cases nephrectomy was performed on the side of the neoplasm and neurological disturbances disappeared after pharmacological treatment and rehabilitation. The third patient was not treated surgically. Embolization was followed by development of spinal cord damage at the level Th12. The patient died of neoplastic cachexia and cardiorespiratory failure.

Correlative biochemical and morphological studies of myelination in human ontogenesis. I. Myelination of the spinal cord

Biochemical, light and electron microscopic observations in six human fetuses between the 16th and 34th weeks of gestation and five infants, 1 day to 3 years old, are presented. The results indicate that myelination of the human spinal cord started before the 16th week of gestation, as a considerable amount of myelin is isolated at this time biochemically, and occasionally axons with loose myelin coils are observed in the electron microscope. It is also stressed that morphological studies are insufficient to evaluate the completion time of the myelination process, as it can be shown biochemically that qualitative myelin maturation takes a long time.

Correlative biochemical and morphological studies of myelination in human ontogenesis. II. Myelination of the nerve roots

Biochemical and morphological observations of nerve roots in six fetuses from the 16th to 34th week of gestation and five infants 1 day to 3 years old are presented. In dorsal roots the process of myelination begins later than in the ventral roots and spinal cord and proceeds much slower. As in the spinal cord during nerve roots myelin maturation profound lipid changes are observed.

The ultrahistochemical picture of the so-called reversed ATPase in the gastrocnemius muscle of the rat

The ultrahistochemical localization of the "reversed" ATPase activity was investigated. Red muscle fibres showed permanent sarcomere contraction, enzymatic activity in the inner membrane and matrix of mitochondria, and large, osmiophilic, probably calcium-containing structures within mitochondria and on their outside. White muscle fibre sarcomeres were relaxed, and activity within their sarcoplasmic reticulum was marked, but slight in the mitochondria. The relaxed state of the sarcomere in the white muscle fibres is supposed to be connected with inactivation of myofibrillar ATPase by acid preincubation, whereas red muscle contraction indicates that acid preincubation does not inactivate their myofibrillar ATPase. That the product of its activity failed to become visible in the sarcomeres is probably due to imperfection of the method. Two sub-types of red muscle fibres were distinguished: those showing only enzymatic activity in mitochondria, and those containing large intra- and extramitochondrial osmiophilic structures. The origin and composition of these structures is difficult to explain. A relation seems to exist between their presence within mitochondria and outside.