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Biomedical subjects

R Petkov

Publications and source records attributed to R Petkov.

At least 37 records · Page 2Linked to original sources
PubMed1995

[The routine immunohistochemical diagnosis and surgical treatment of medullary carcinoma of the thyroid].

Over the period 1977 through 1988, in the Research Institute of Surgery--Medical Academy a total of 372 patients undergo primary operative management for thyroid gland carcinoma. Medullary carcinoma is discovered in 18 patients of the series (4.8 per cent). The preoperative diagnosis is supplemented by thyroscintigraphy with 131iodine or technetium Tc 201. After 1981, calcitonin and carcinoembryonic antigen (CEA), specific medullary thyroid carcinoma (MTC) markers, measurements are routinely done, with substantially elevated levels in the patients under study being found, in those with metastases inclusive. Presumably, the preoperative diagnosis medullary thyroid carcinoma is very difficult, and only a combined approach, including thyroidectomy with ensuing iodine radiotherapy, may account for a good survivorship. Postoperatively, all patients with MTC diagnosis are regularly tested for serum calcitonin and CEA levels. The carefully taken family history and questioning of the patients allows to differentiate familial from cases from sporadic neoplasms.

Adult↗
PubMed1995

[Early thymectomy in the treatment of myasthenia gravis].

Over a 10-year period, 1983 through 1992, in the clinic of endocrinologic surgery--Alexander Hospital, Sofia, 89 patients with myasthenia gravis (MG), 57 women and 32 men, are subjected to operative treatment--thymectomy. The mean age in women is 32 years (range 19 to 68), and in men--45.6 years (range 25 to 70). Two age-related distributions in the series are impressive--in female patients the peak is between 20 and 30 years, whereas in men--between 45 and 55 years. The operative intervention consists in total thymectomy. Preference is given to the trans-sternal median access to the thymus gland. In the complex therapeutic approach to MG are included also a number of drugs and other agents--corticosteroids, anticholinesterase agents, immunosuppressives and the like. Patients undergoing operative thymectomy are usually given preoperative treatment with anticholinesterase drugs for different periods of time. Operation is undertaken only in stable condition of the patients. Good postoperative results are recorded in 57 per cent of those operated by the first year, with a satisfactory improvement in 29.2 per cent of them. In the third group (13.4 per cent) the postoperative results are poor, and treatment is proceeded with anticholinesterase drugs or immunosuppressives. The average follow-up term is 44.7 months. The delay in improvement is typical of patients with longer duration of the complaints, but it may be attained within 2, 3 or 5 years postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[The surgical treatment of myasthenia gravis--the authors' own experience].

Proceeding from personal experience accumulated hitherto, the indications for both operative treatment of MG, and choice of the most adequate preoperative preparation and timing of thymectomy, are precisely determined. Pathohistologic findings and postoperative results in 47 patients, thymectomized in the period 1989 to 1994, are followed up and analyzed. The inference is reached that preliminary stabilization of the patient's condition with anticholinesterase drugs, and early and total thymectomy are essential for the successful outcome of treatment. It is preferable that thymectomy is done within six months of the occurrence of complaints or making the diagnosis.

Adult↗
PubMed1995

[The surgical treatment of creeping infections along the flexor tendons of the foot in diabetics].

Creeping infections along the flexor tendons of the foot are taken to be a common underlying cause of limb amputation in diabetics. Usually the process originates from the toes, and spreads along the course of the long flexors. The procedure of selective resection of the tendons involved suggested enables to complete the surgical treatment with economical operative intervention--amputation of a single toe, or amputation at transmetatarsal level.

Bacterial Infections↗
PubMed1995

[Economic surgical interventions on the foot in diabetic gangrene].

Primary surgical toilet is the main stage of surgical management of diabetic gangrene, usually associated with amputation of isolated toes, or varying in type transmetatarsal amputations. Elimination of the basic tissue decomposition and wide exposure of all purulent cavities contribute greatly to restrict the purulent gangrenous process in course. Simultaneously, adequate insulin and antibiotic therapy is conducted. If necessary, at a second stage plastic reconstructive operations are performed with a view to improve the biomechanics of the foot.

Anti-Bacterial Agents↗
PubMed1995

[Struma nodosa and cancer of the thyroid].

The disputable issue of the pathogenetic relation between struma nodosa and thyroid gland carcinoma is discussed. A total of 234 patients with definitive diagnosis thyroid carcinoma, operated in the clinic of endocrine surgery--Higher Medical Institute, Sofia, are retrospectively analyzed. Clinical, past history and pathomorphologic data are considered--123 patients present papillary carcinoma, 67--follicular, and 42--mixed form. All patients undergo operative management over the period 1980 through 1991. Later, to the aforementioned group are added further 50 patients with carcinoma of the thyroid, treated from 1991 to late December 1992, and thus the total number amounts to 284 cases--153 papillary, 79 follicular and 52 mixed forms, respectively. In 67.2 per cent of the cases the thyroid carcinoma presents clinical patterns of a solitary node, in 27.8 per cent--node of multinodular struma, and in 4.9 per cent--formation associated with another thyroid disease. Multifocal location is established in five cases. As shown by the pathomorphological study in 18 per cent of the cases it is a matter of a combination--thyroid carcinoma and struma multinodosa, and in 1.2 per cent of the cases only there is conclusive evidence of solitary adenoma malignization. The obtained results lead to the inference that thyroid carcinoma deriving from the nodose structures of the gland is an exception, rather than rule.

Adenocarcinoma, Follicular↗
PubMed1995

[Recurrences and metastases in differentiated thyroid cancer].

A total of 201 patients presenting differentiated thyroid gland carcinoma (DTGC), all of them in T1-3Ha-bMo stage, are followed up over a 10-year period, 1980 through 1989. Thyroidectomy with ensuing 131I radiotherapy is used in the treatment of 74 cases, and varying in extent resections--in the remainder. Women up to 50, and men up to 40 years of age (totalling 138 cases) are assigned to low-risk age groups (LRG), and those exceeding the aforementioned age limit (63 cases)--to high-risk age groups (HRG). Local recurrences and lymph node metastases are recorded in 17.5 per cent of the patients undergoing thyroidectomy followed by iodine radiotherapy. Among those subjected to radical resections the rate of recurrences of the lesion amounts to 2.4 per cent. In the HRG the rate of recurrences among thyroidectomized patients is 32 per cent, whereas in those assigned to LRG, treated with organ salvaging operations, the recurrences are 10.1 and 1.1 per cent, respectively. It is established that insofar as recurrences of the lesion are concerned the fifth year remains a high-risk period; by the second year they are increased more than three times. Lymph-node metastases are observed in 80 per cent of the cases by the second year. Local recurrences are more common in HRG--83.3 per cent. As shown by the results of the series reviewed, thyroidectomy followed by 131I radiotherapy fails to improve the prognosis in HRG patients. In these cases better results are attained in those subjected to wide resection of the thyroid gland.

Adenocarcinoma↗
PubMed1992

Perioperative myocardial protection with the calcium antagonist diltiazem.

The effect of the calcium channel blocker, diltiazem, on cardiac performance was examined in 90 patients who underwent isolated aortic valve replacement for aortic valve diseases with marked left ventricular hypertrophy. The patients were randomly assigned to one of five groups dependent on the treatment plan with diltiazem: group 1, 5-day preoperative treatment with oral administration of 60 mg diltiazem 3 times daily, 10 mg diltiazem intravenously as a bolus dose before the beginning of the cardiopulmonary bypass, and 5 mg diltiazem intravenously 10 min before removal of aortic clamp; group 2, 5-day preoperative treatment with oral administration of 60 mg diltiazem 3 times daily; group 3, 10 mg diltiazem intravenously as a bolus dose before the beginning of CPB and 5 mg 10 min before removal of the aortic clamp; group 4, 15 mg diltiazem in 1000 ml cardioplegic solution, given as additive; group 5, control group not receiving diltiazem. All operative procedures were performed in an identical manner with an average cross-clamping time of 57.7 min and cooling the heart down to 16 degrees-17 degrees septal temperature by perfusion of the coronary arteries with 4 degrees C cold cardioplegic solution. In each patient the heart rate (HR), cardiac output and cardiac index (CO, CI), stroke volume index (SVI), left ventricular stroke work index (LVSWI) and systemic vascular resistance index (SVRI) were recorded and calculated before and after the ischemic period. Transmural samples were obtained three times by needle biopsy technique from the anterior free wall of the heart. Analysis of the variables revealed that: (1) complete cessation of electromechanical activity was achieved significantly more rapidly in groups 1 and 3 than in the other groups; (2) recovery of sinus rhythm and function of the conductive system required significantly longer in groups 1 and 3; (3) the time-related values of the important hemodynamic factors (CO, CI, LWSVI and SVRI) showed a significantly more effective postperfusion cardiac performance in groups 1 and 3 than in groups 2, 4 and 5. An oral dose of 180 mg diltiazem for 5 to 7 days preoperatively in combination with intravenous administration of 10 mg before the beginning of CPB and 5-10 mg during reperfusion can be recommended in patients undergoing open-heart surgery for isolated aortic valve diseases and left ventricular hypertrophy.

Administration, Oral↗
PubMed1990

Incidences and surgical aspects of cardiac myxomas in Bulgaria.

63 patients with cardiac tumors underwent operative treatment between January 1970 and December 1988. Three additional patients refused the operation, despite the large left atrial myxomas and obstruction of the mitral valve, recognized by echocardiography. 62 patients had benign tumors: the only malignant neoplasm was a fibrosarcoma, originating from the right ventricle. Myxomas were found in 57 patients: 54 were located in the left and 2 in the right atrium. In one case the myxoma originated from the left ventricle. The hospital mortality of the 22 patients who underwent excision of cardiac myxomas between 1970 and 1984 was 18.18% (4 deaths), and 2.44% (1 death) of 41 patients operated on from 1984 to 1988 for cardiac tumors (35 of them with myxomas). During the follow-up time of 6 to 140 months, recurrence of myxomas occurred in only one patient, 4 years after surgery for multifocal myxoma in the left atrium. Surgical excision of the myxoma is the only acceptable therapy able to cure. Without surgical treatment, the medium and long-term prognosis is fatal. Therefore once the cardiac myxoma is identified by two-dimensional echocardiography, the tumor should be removed even in patients without symptoms. The removal of myxomas doesn't require excision of the full thickness of the interatrial septum or ventricular wall. The risk of postoperative arrhythmias after extensive excision increases. Conduction disturbances may be related to the resection of a large area of the atrial septum or wall. No recurrences have been registered after less radical procedures-- removal with excision only of the underlying endocard.

Bulgaria↗
PubMed1987

[Hygienic research on meat-dressing shops and enterprises].

Observations were made on the hygiene state of the meat-conditioning departments and enterprises of 13 meat-dressing combines. Both qualitative and quantitative investigations were carried out with regard to 9 bacteriologic indexes. The result of studies on a total of 1,042 samples of washings taken from equipment, working tools, machines, working milieu, and hands and aprons of workers prior to beginning work showed that in case all regulations of cleaning, washing, and disinfection were observed the residual microflora, and, more specifically organisms that were of interest from a sanitary point of view were lowered to minimum counts. No pathogenic Staphylococcus and Salmonella organisms were isolated. It was found that during work the count of indicative organisms considerably rose. No pathogenic staphylococci were isolated. In one case only were there Salmonella typhimurium organisms on the surface of a circular saw for carcass cutting. The overall bacteriologic investigation of a total of 137 samples of minced meat and meat balls and other products prepared with such meat revealed that the average counts of various organisms ranged as follows: aerobic mesophiles--3,653 830/g, and coliforms--31,748/g; Escherichia coli organisms were demonstrated in 10.22 per cent of the cases, B. proteus--in 1.46 per cent, and pathogenic staphylococci--in 3.65 per cent of the samples. None of the samples, weighing 25 g each showed the presence of Salmonellae. No correlative dependence was found between the coli titer and the coli index of the products.

Animals↗
PubMed1986

[Fatty acid content of the lipid fraction of the meat from deer and roe deer].

Investigations were carried out on musculus longissimus dorsi as sampled from 8 deer, weighing 90 to 120 kg, and from 10 fallow deer, weighing 25 to 35 kg, hunted in the autumn-winter season of 1983-1984. Fatty acid determination was performed via gas chromatograph Pye Unicam, model 104, supplied with a flame-ionization detector. It was found that the average content of fatty acids in the lipid fraction of m. longissimus dorsi from deer in percent to the total amount of fatty acids was 1.82% for myristic acid, 0.21% for tetradecenic acid, 30.17% for palmitic acid, 1.88% for palmitoleic acid, 19.42% for stearic acid, 43.18% for oleic acid, 3.32% for linoleic acid, while the ratio between saturated and unsaturated fatty acids had a numerical value of 1.06. With fallow deer the average amount of fatty acids in the lipid fraction of m. longissimus dorsi in percent to the total amount of fatty acids these figures were 3.46, 0.59, 30.48, 2.44, 20.15, 40.41, 2.47%, and 1.18, respectively. With both species of animals traces were also found of linolenic and arachidonic acids.

Animals↗
PubMed1985

[Electrophoretic method of demonstrating antibiotic residues in meat and eggs].

Studies were carried out on Smither and Vanghan's electrophoretic method with the use of high voltage. The method was found to be readily reproducible and to have good sensitivity. It could be successfully used in the demonstration and identification of residual amounts of antibiotics in meat and eggs. It was also established that with the use of agarose of pH 6.0 amino glycosides, beta-lactams, flavomycin, spectinomycin, and monensin showed higher migration capacity. The same value of pH was contributive to increasing the migration distances with macrolites, zincbacitracin, and tetracyclines. It was demonstrated that the use of electric current at 50 MA made it more favourable to separate and identify antibiotics. B. subtilis BGA was found to be more sensitive than B. mycoides v. cereus ATCC 11778 with regard to the antibiotics used and it could be made use of in the demonstration of minimal amounts.

Animals↗
PubMed1985

[Chemical composition of the meat from chickens treated with aflatoxin B1].

Studies were carried out to establish the effect of aflatoxin B1 on some qualitative indices of poultry meat. It was found that the use of aflatoxin B1 led to a decrease in the live weight as well as to changes in the chemical composition of meat-increase in the water content, decrease in the amount of fats and proteins, and drop of its biologic value. Most clearly manifested were the changes when aflatoxin B1 was applied at the rate of 37.5 micrograms daily, in the course of 30 days. It was also found that withdrawal periods of 7 days did not contribute to the elimination of the changes in the chemical composition of poultry meat.

Aflatoxin B1↗
PubMed1985

[Paraclinical research on broiler chickens treated with aflatoxin B1 and microbiological studies of the meat and liver obtained from them].

Studied were some paraclinical indices of the blood of 50 broiler birds treated with aflatoxin B1. It was found that the effect of the mycotoxin used in concentrations of 25.0 and 37.5 micrograms in the course of thirty days and in conc. of 50.0 micrograms in the course of five days with three test groups of birds (as compared to a group of controls) consisted in the drop of total protein and the rise of the activity of GOT, GPT, and total bilirubin. It was demonstrated that the use of feeds containing aflatoxin B1 had a bearing on the microbiologic status of the meat and liver. There was no increase in the total count of aerobic mesophile organisms.

Aflatoxin B1↗
PubMed1985

[Fatty acid content in the lipid fraction of the meat of wild pigs].

The content of fatty acids was studied in the lipid fraction of m. longissimus dorsi of wild swine weighing 70 to 100 kg shot in the autumn-winter season of 1983-1984. A gas chromatography device of the Pye Unicam system, model 104 with a flame-ionization detector was used. It was found that the average content of fatty acids in the lipid fraction of m. longissimus dorsi in terms of percent of the total amount of the fatty acids was 1.57 for myristic acid, 25.78 for palmitic acid, 11.14 for stearic acid, 2.32 for palmitoleic acid, 50.90 for oleic acid, and 8.29 for linoleic acid. Linolenic acid and arachidonic acid were in trace amounts only.

Animals↗
PubMed1984

[Dextrofer-100 with B12 and dextrofer-100--comparative pharmacological and clinico-pharmacological studies].

Comparative studies were carried out with dextrofer-100 with B12 and dextrofer-100 in terms of acute toxicity (albino mice), absorption (rabbits, pigs, and lambs), deposition of iron in the liver and spleen (rabbits, pigs, and lambs) and antianemic action (pigs and lambs). It was found that LD50 of dextrofer-100 with B12 at i/v introduction into 18-20-gram albino mice was 1750 mg Fe3+/kg body mass; with regard to toxicity it was shown to correspond to the British Veterinary Code. The toxicity of dextrofer-100, studied by the same test, was practically undeterminable. By the level of sideremia dextrofer-100 with B12 did not differ essentially from dextrofer-100 and was said to belong to preparations with rapid absorption. It was most rapidly absorbed in pigs, rabbits and lambs following next. It supplied enough iron to the reticuloendothelial organs--in pigs it was (on a percent basis) highest in the liver, and in lambs--in the spleen. In pigs on the 10th day following treatment with dextrofer-100 with B12 the liver was shown to have vitamin B12 5 times as much. By its antianemic effect at i/m application to newborn pigs and lambs dextrofer-100 with B12 did not differ essentially from dextrofer-100 (its action was negligibly broader), however, it was beneficial to the growth of pigs.

Absorption↗