Selected Factors of Experiencing Pregnancy and Birth in Association with Postpartum Depression

BACKGROUND

The aim of the study is to analyse the risk of postpartum depression using dimensions of perceived support (information, emotional, and physical), antenatal education (satisfaction and attitude), and attitude toward pregnancy (wanted or unwanted).

METHODS

A cross-sectional study was carried out among 584 postpartum women in two university birth centres in Slovakia. The Edinburgh Postnatal Depression Scale (EPDS) score was used. Descriptive statistics and analysis of variance, as well as logistic regression, were employed in the study. Found associations were adjusted for education level, type of birth, psychiatric history, and age.

RESULTS

As many as 95.1% of women reported their pregnancy as being wanted. Antenatal education, particularly satisfaction with it, showed a negative association with the EPDS score level. No significant differences in depression levels were found considering attitude toward pregnancy and perceived support.

CONCLUSIONS

The study pointed out the significance of antenatal education to lower the risk of the postpartum depression. One of the important criteria of effective education is a woman's subjective satisfaction with it.

Virtual patients: an option for future distance midwifery education?

BACKGROUND

The objective is to introduce the creating a set of virtual patients (VPs) to support distance midwifery education as well as the impact of distance education by means of VPs on knowledge, skills, motivation, clinical practice, and student satisfaction.

METHODS

VPs were created using OpenLabyrinth (OL). The impact of the distance education was assessed using a feedback questionnaire.

RESULTS

When creating our own VPs, the design and development phase can be considered the most difficult. On a scale of 1 (agree) to 4 (disagree), the student feedback rates were mostly positive (1.04-2.13). A high degree of agreement was associated with the acquisition of theoretical knowledge (1.15-1.28) and skills (1.43).

CONCLUSIONS

The creation of our own VPs is challenging for teachers due to its unconventional character. The students expressed great satisfaction with distance learning, but lacked face-to-face contact with the patient.

Factor Structure of the Edinburgh Postnatal Depression Scale in a Sample of Postpartum Slovak Women

BACKGROUND

Postpartum depression has a negative impact on quality of life. The aim of this study was to examine the factor structure and psychometric properties of the Slovak version of the Edinburgh Postnatal Depression Scale (EPDS).

METHODS

A paper and pencil version of the 10-item EPDS questionnaire was administered personally to 577 women at baseline during their stay in hospital on the second to fourth day postpartum (age, 30.6 ± 4.9 years; 73.5% vaginal births vs. 26.5% operative births; 59.4% primiparas). A total of 198 women participated in the online follow-up 6-8 weeks postpartum (questionnaire sent via e-mail).

RESULTS

The Slovak version of the EPDS had Cronbach's coefficients of 0.84 and 0.88 at baseline (T1) and follow-up, respectively. The three-dimensional model of the scale offered good fit for both the baseline (χ²_{(df = 28)} = 1339.38, p < 0.001; CFI = 0.99, RMSEA = 0.02, and TLI = 0.99) and follow-up (χ²_{(df = 45)} = 908.06, p < 0.001, CFI = 0.93, RMSEA = 0.09, and TL = 0.90). A risk of major depression (EPDS score ≥ 13) was identified in 6.1% in T1 and 11.6% in the follow-up. Elevated levels of depression symptoms (EPDS score ≥ 10) were identified in 16.7% and 22.7% of the respondents at baseline and follow-up, respectively.

CONCLUSIONS

The Slovak translation of the EPDS showed good consistency, convergent validity, and model characteristics. The routine use of EPDS can contribute to improving the quality of postnatal health care.

Creation of virtual patients for midwifery education

OBJECTIVE

The objective of the study was to create several new, original virtual patients (VPs) in the Slovak language, especially for educational purposes in midwifery.

SETTING

Virtual patients have been created for the needs of university midwifery education in Slovakia.

MODEL

The creation of the six virtual patients basically consisted of three fixed stages: preparation, design and development, implementation into the virtual environment. We used the Open Labyrinth (OL) virtual environment, an open-source system for creating VPs. The VPs include six various scenarios of the most common problems seen in midwifery practice: preterm birth, perinatal loss, gestational diabetes, ineffective breastfeeding, postpartum bleeding and sudden home birth.

FINDINGS

Currently, six original virtual patients are used in university midwifery education in Slovakia. We use them for contact teaching as well as self-study of students. They present the first VPs in Slovakia and the Czech Republic created in academic settings in these countries.

CONCLUSIONS

The future perspective of a virtual patient as an interactive process between the student and the medium is that it can deepen and improve learning outcomes, solve specific midwifery issues, and reduce mistakes in the clinical environment.

[Atypical maxillofacial shot wound]

Maxillofacial shot wounds belong to the relatively less frequent injuries. The soft tissues might be affected in particular, however the most of injuries are combined with infliction of hard tissues. Shot wounds by the bow or crossbow are very rare. They might result as a consequence of either accident or suicide. In the literature some cases of a suicidal experiments had been published, all of these cases were due to arrow from the crossbow. There was no injury being documented due to arrow from the bow. The authors present a case of maxillofacial injury done by shoot of arrow from the bow in the course of a child's play.

[Scintigraphic detection of osteoblast activity after implantation of BAS-0 bioactive glass-ceramic material into long bone defects]

PURPOSE OF THE STUDY

The aim of the study was to demonstrate, by three-phase bone scintigraphy, radionuclide uptake at the site of defects in long bones filled with the non-resorbable bioactive glass-ceramic material BAS-0 at a long follow-up.

MATERIAL

Twenty patients, 14 men and 6 women, operated on between 1990 and 2000 for benign bone tumors or tumor-like lesions localized in the femur, tibia or humerus were comprised in the study. Their average age at the time of operation was 14 years (range, 8 to 24). The diagnoses based on histological examination included juvenile bone cysts in 11, aneurysmal bone cyst in five, non-ossifying fibroma in two, and fibrous dysplasia in two patients. The lesions were localized in the femur, humerus and tibia in 11, five and four patients, respectively. The metaphysis was affected in eight and the diaphysis in 12 patients.

METHODS

Clinical, radiological and scintigraphic examinations were carried out at 2 to 12 years (7 years on average) after surgery. The clinical evaluation included subjective complaints and objective findings. Radiographs were made in standard projections and the osteo-integration of glass-ceramic material was investigated. Three-phase bone scans were made and the healthy and the affected limbs in each patient were compared by means of an index. Radionuclide uptake was considered normal when the index value was equal to 1.0, mildly increased at an index value of 1.2, moderately increased at 1.2-1.5 and markedly increased at an index value higher than 1.5.

RESULTS

The clinical evaluation showed that, in the patients with glass-ceramic filling of metaphyses, six had no subjective complaints and two reported transient pain. In the patients with implants in diaphyses, subjective complaints were recorded in nine and no complaints in three patients. No inflammatory changes in soft tissues were found. No restriction in weightbearing of the limb treated was reported by any of the patients. On radiography, 18 patients were free from any disease residue or recurrence. Two patients had a residual defect. The bioactive glass-ceramic material BAS-0 was completely incorporated in all patients. On three-phase bone scans, radionuclide distribution on the flow phase and soft tissue phase was symmetrical in both limbs of all patients. For the metaphyseal location of implants, the delayed images demonstrated physiological radionuclide distribution in one patient, mildly increased distribution (index up to 1.2) in four, increased uptake (index up to 1.5) in two patients, and highly increased uptake (index above 1.5) in one patient. For the diaphyseal location of implants, the delayed scans demonstrated slightly increased radionuclide distribution in two, markedly increased in two and highly increased uptake in eight patients.

DISCUSSION

The tissue during incorporation of a non-resorbable synthetic material is influenced by stress-shielding. This changes local mechanical signals, which has a negative effect on the adjacent bone tissue. Stress accumulating at the interface of a rigid implant and bone tissue may result in pain, and is detected by scintigraphy as an increased nucleotide uptake, particularly in diaphyseal grafts.

CONCLUSIONS

This paper presents problems associated with implantation of the non-resorbable bioactive glass-ceramic material BAS-0 in the treatment of diaphyseal defects of long bones. The results show that, for filling of the defects described herein, non-resorbable glass-ceramic materials are not suitable.

Selective medium for primary isolation of members of the tribe Proteeae

A selective Proteeae medium (SPM) for isolation and preliminary detection of species of genera Proteus, Morganella, and Providencia was evaluated. The SPM contains tryptose phosphate agar with phenolphthalein monophosphate (as substrate for phosphatase activity), bile salts and polymyxin B (as inhibitors). The selectivity of the SPM was tested by the ecometric method of quality assurance of culture media. Fourteen reference cultures of enterobacteria and fifty-four strains of Proteeae were tested for their absolute growth index (AGI). Ninety-five percent of tested Proteeae strains display an AGI above 2.5. The detected phosphatase activity proved to be able to discriminate colonies of members of the tribe Proteeae. The ability of SPM for primary isolation of members of Proteeae was tested on food and clinical material and 94 strains were isolated. In addition, the SPM was employed in routine practice of clinical microbiology. From 1016 clinical samples (stool, urine, vaginal and urethral swabs), 57 strains of Proteeae were detected by the SPM in contrast to 35 strains by the routine procedure. The difference amounts to nearly 40%.

[Blunt injury of the kidney--personal experience and present views on its therapy]

Between 1972 to 1994 there were admitted 105 patients with blunt trauma of the kidney, 89 men and 16 women with median age 32 years. In 53 patients the left kidney was affected and in 52 of them the right side was injured. According to the grade of trauma we evaluated in 77 patients a contusion (73.3%), by 16 patients a laceration (15.2%), in 11 patients a rupture of the kidney with fragmentation of the parenchyma and in one the renal artery was injured. The mechanism leading to the blunt trauma of the kidney was following: traffic accident in 52 patients (49.5%), during sport in 20 patients (19.5%). 16 patients were injured in own home (9.5%) and 7 patients in work (6.7%). In 28 patients the trauma of the kidney was serious, by 5 of them we have done nephrectomy (17.8%), in two suture of the parenchyma (7.1%) and in further two patients heminephrectomy. After considering clinical status, grade of hypovolemic shock and finding on CT scan we prefer lately conservative steps in the treatment serious trauma of the kidney.

[Monitoring the incorporation of bioactive glass ceramics in the area of the acetabulum after surgical revision of the hip joint arthroplasty by scintigraphy.]

The authors investigated changes of osteoblastic activity at the site of a reconstructed defect of the acetabulum after aseptic loosening of a total endoprosthesis of the hip joint by administration of an osteotropic radiopharmaceutical preparation, methylendiphosphonate, labelled with 99mTc. The defect of the acetabulum was filled with bioactive glass ceramic material BAS-0 (Lasak Co., Prague) in the shape of dense granules 4-8 mm in size and a metal antiprotrusion basket. Into the reconstructed acetabulum a new polyethylene socket of the endoprosthesis was implanted. Examination by the two-head camera Helix of Elscint Co. was performed within two weeks after operation. Healing in the described group of ten patients was without complications, after three months the patients burdened the operated joint partly, after six months they burdened it by half their weight and after another three months by their whole weight. Immediately after operation the metabolic acitivity in the vicinity of the defect exceded the reference activity of normal bone by 50% The authors discuss possibilities and advantages of the mentioned examination in investigations of the incorporation and function of glass ceramic prostheses of osseous tissue. Key words: bioactive glass ceramics, scintigraphy, osteotropic radiopharmaceutical preparation, 99mTc methylendiphosphonate, reconstruction of acetabular defect.

[Cysts and pseudocysts of the spleen in children]

A cyst in the upper pole of the spleen was diagnosed in three children. In all the pole of the spleen was resected -in two instances it contained a cyst, in one a pseudocyst. The postoperative course was without complications. All patients had scintigraphic check-up examinations, in all three instances functional lienal tissue was found which did not differ much as to its size from that of a normal spleen. In cysts situated in the splenic pole the authors consider partial resection of the affected portion of the spleen as the optimal surgical method. In cysts of other portions of the spleen it would be better to select a different surgical procedure, e.g. enucleation of the cysts, partial decapsulation of the cyst or percutaneous puncture of the cyst combined, if necessary, with sclerotization.

[Identification of Citrobacter species and their occurrence in raw products and foods]

Fifty-nine strains of bacteria were tested in study that were isolated from raw materials and foods (raw milk, farm milking parlors, sausage meat, raw potatoes, cheese, frozen oven-ready foods, confectionery products, cold dishes), and they were included in the genus Citrobacter using a commercial diagnostic kit ENTEROtest 16 (Lachema a.s., Brno), numeric identification program TNW (Czech Collection of Microorganisms, Faculty of Science of Masaryk University at Brno) and identification key (O'Hara et al., 1995). The results of the ENTEROtest itself, including OXI and ONPtests, did not provide satisfactory discrimination of detected strains to the level of species since 64.4% were identified by the genus by TNW program or designated as intermediary strains. Correct species identification was obtained in 33.9% only (Tab. I). Five next conventional tests (dulcitol, alpha-methyl-glucoside, raffinose, melibiose, arginine dihydrolase) were used and their results successfully specified 94.9% tested strains to the species level (Tab. I). A dichotomic identification key (O'Hara et al., 1995) enabled to classify the strains on the basis of the results of ENTEROtest 16 and two conventional tests (dulcitol, melibiosis) relatively easily, and it can be recommended for routine identification of typical Citrobacters from foods. Only ten strains were classified in a wrong way (16.9%) due to false results in ENTEROtest (Tab. II). Tab. III shows the strains classified wrongly by both identifications systems. The tested set contained Citrobacter braakii in a majority of cases (30 strains), followed by C. freundii (17 strains), C. youngae (6 strains), 2 strains of genomospecies 10 and one strain of C. koseri, C. amalonaticus and C farmeri. Tab. IV shows the presence of Citrobacter species in the particular raw materials and foods. The most frequently present species in raw materials: C. braakii (26 strains, 68.4%), C. freundii (3 strains, 7.9%) and C. youngae (3 strains, 7.9%). Foods contained these three species only: C. freundii (14 strains, 66.7%), C. braakii (4 strains, 19.0%) and C. youngae (3 strains, 14.3%). The percentage of the three most frequently present species in raw materials is substantially different from their percentage in foods (Fig. 1). The higher percentage of C. freundii presence in foods can be ascribed to secondary contamination.

[The NEFERM test in the identification of psychrotrophic bacteria isolated from milk and dairy products]

Sanitary and nutriti on quality of foods from animal sources, that means also of milk and dairy products, are significantly influenced by the presence of psychrotrophic bacteria, the lipolytic and proteolytic activity of which contributes to their nutritive and sensory changes. This applies particularly to psychrotrophic bacteria of the genus Pseudomonas, Shewanella, Alcaligenes and Flavobacterium (Muir and Phillips, 1984; Piton and Richard, 1985; Craven and Macauley, 1990). These bacteria cause raw and pasteurized milk to turn bitter and gelatinize, and/or technological problems during processing. In the present paper the possible use of NEFERM-test and numerical identification system TNW was verified for identification psychrotrophic, nonfermentative bacteria isolated from milk and dairy products. This research is a continuation of our preceding work (Urbanová and Pácová, 1995) dealing with identification of these bacteria in poultry. The test comprised 35 psychrotrophic, gram-negative, oxidase-positive nonfermentative bacteria isolated from raw milk (30 strains) and hard cheeses (5 strains). A commercial diagnostic kit NEFERM-test (Lachema a.s., Brno) and respective conventional methods were parallelly used for identification: the conventional methods were complemented by assays of oxidase (OXI) and beta-galactosidase (ONPG) using of commercial strips Lachema a.s. Additional tests were as follows: gelatin and Tween 80 hydrolysis, fluorescein production. The readings of yellow or orange pigment production were also applied. A numerical identification system TNW was used to process the results (Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Brno). Correct identification of bacteria by means of commercial diagnostic kits depends particularly upon the high goodness of fit of the results obtained by conventional tests in relation to those obtained by commercial kits.(ABSTRACT TRUNCATED AT 250 WORDS)

[The NEFERM-Test for identification of psychrotrophic bacteria in food]

Identification of gramnegative nonfermentative bacteria by traditional methods requires much labor and time consumption. Therefore in this study we tested the use of an available commercial diagnostic kit and processing of its results by computerized numerical identification systems. Identification involved 83 gramnegative, psychotrophic, nonfermentative, oxidase-positive bacteria isolated from just slaughtered and deep-frozen chickens. The strains were isolated from primary cultures in Psedomonas F and Endo agar, Violet Red Bile agar (IMUNA, OXOID) and King B agar (King et al., 1954), under two cultivation regimes (room temperature for three days and 7 degrees C for 10 days). A commercial kit for diagnostics of nonfermentative bacteria in clinical microbiology under the name NEFERM-test (Lachema a.s., Brno) containing 12 biochemical assays was used for strain identification: GLU, AGR, IND, ESL, SCI, PHS, URE, MAN, XYL, MLT, LAC, NIT. All these assays were conducted parallelly by traditional methods. Additional tests involved the use of OXI and ONPG commercial strips (Lachema a.s., Brno), gelatin and Tween 80 hydrolysis (Pácová and Kocur, 1984) and fluorescein production (King et al., 1954). These identification systems were used to process the results of tests; index and differentiation table (Lachema a.s., Brno) and numerical computerized systems TNW (Czech Collection (Z. Svoboda, Jihlava). Various shortened procedures, identification keys and systems are used to speed up identification of gramnegative nonfermentative bacteria. Available commercial identification kits (API NE20) in form of microassay have been developed particularly for diagnostics of bacteria from clinica materials, which applies to NEFERM-test of the Czech make.(ABSTRACT TRUNCATED AT 250 WORDS)

[Identification of reference strains of intestinal bacteria using the TNW, IDENTI and NIS 86 numeric identification systems]

A total of 176 reference strains including 63 species of Enterobacteriaceae mainly of clinical origin were tested by commercial diagnostic kits ENTEROtest 1 & 2. The identification efficacy in both systems TNW and IDENTI was nearly in agreement 144 (81.8%), 142 (80.7%) respectively correctly identified strains. The NIS 86 system identified only 54 (30.7%) strains correctly.

[Scintigraphic imaging of the heart in dogs damaged by irradiation]

The paper verified literature data assuming that the heart damage caused by irradiation of thorax may be scintigraphically detected by means of 99mTc-pyrophosphate. Three dogs underwent a single irradiation of thorax with a gamma cobalt source by the Dose 40 Gy. The myocardium scan was performed 24 hours, 20 days, 50 days, 80 days and 93 days after the irradiation. The scintigraphic examination proved to be negative at all the intervals observed. A comparison of the scan with morphological findings and with radioactivity of tissue samples after the dogs were sacrificed 93 days after the irradiation proved that the negativity of the pyrophosphate scintigraphy was caused by a minimum damage of the myocardium and not by an inability of 99mTc-pyrophosphate to be incorporated into radiation lesions. The data in literature on myocardium damage by irradiation appear to be considerably exaggerated.

[The pathophysiologic basis for the incorporation of 99mTc-pyrophosphate into myocardial infarct]

The investigation studied the relation of 99mTc-pyrophosphate incorporation (99mTc-PYP) into experimental, 48-hours old myocardial infarction in dogs to tissue vascular supply and to the extent of necrotic tissue. The experimental myocardial infarction was induced in five animals during an operation by the ligation RIVA. The myocardial blood supply was measured in tissue samples, taken from transverse sections of the infarction by means of 86Rb captation. The extent of myocytolysis was measured by depletion of tissue creatine kinase (CK). In the subendocardial layer of the infarction it became obvious that 99mTc-PYP incorporation was proportional to the decrease of tissue blood supply. No relation between the extent of necrosis and the incorporation of the radioactive chemical was demonstrated. The accumulation of 99mTc-PYP requires the necrosis to be present, but its extent apparently does not influence the intensity of incorporation. In the subepicardial infarction layer there was neither a relation of the radioactive chemical cumulation to the blood flow, nor to the extent of the necrosis proved.

Effect of different oxygen concentrations in the gas phase on biochemical activities of goat mammary tissue in organ culture

Non-secretory mammary explants from virgin goats showed higher RNA and protein synthesis in a low O2 gas phase (air) than in high O2 (95% O2). Lipid and casein synthesis was not affected significantly by the concentration of O2 in the atmosphere during culture. On the other hand, the more developed mammary tissue from primigravid goats showed higher lipid, casein and protein synthesis in 95% O2. The relative response of mammary tissue to hormones was not substantially different when cultured in the presence of a low or high O2 gas phase. As Hepes-buffered medium was found not to need a supply of CO2 to maintain the correct pH and as Hepes did not interfere with biochemical activities of cells, it is recommended to use it for cultures in a low O2 gas phase.

99mTc-aminohexylidendiphosphonate and 99mTc-pyrophosphate in the scintigraphic diagnosis of experimental myocardial infarction in dogs

99mTc-aminohexylidendiphosphonate (99mTc-AHDP) is a new Czechoslovak pharmaceutical of the phosphonate line which contains the amino group NH2 in its molecule. This substance was tested in 5 dogs with experimentally provoked 48-h old myocardial infarction. The in-vivo scan and the radioactivity of tissue samples demonstrated that 99mTc-AHDP is as suitable for imaging acute myocardial infarction as is the commonly used 99mTc-pyrophosphate.

[Determination of the number of somatic cells in milk using the rapid diphenylamine DNA filter method]

The rapid reaction of the diphenylamine agent with DNA was used for the determination of the counts of somatic cells in cow's milk, using the DNA filter method. The method is based on the filtration of a warmed (65-70 degrees C) mixture of milk with Triton X-100 through the Synpor nitrocellulose membrane filter, pore size 2 to 5 microns, and subsequent DNA determination of the collected somatic cells by the colour reaction of diphenylamine. A 2ml quantity of distilled water and 4 ml of diphenylamine reagent were added to the membrane filters with somatic cells. The mixture is warmed in water bath at 90 to 100 degrees C for 20 min., then it is cooled, centrifuged (3500 X g, 15 min.), and the optical density is measured at 595 nm. The relation 8 micrograms = 1 million cells was used for the conversion of DNA content to the counts of cells. The average variation coefficient of the determination was 5.9% and the coefficient of correlation between the diphenylamine DNA filter method and the direct microscopy of the somatic cells on membrane filters was r = 0.997. Using the diphenylamine DNA filter method, the counts of somatic cells can also be determined from milk samples stored in frozen condition or from the filters with collected cells kept at the temperature of 4 degrees C (10 days) or 25 degrees C (3 days). Milk stabilized with formaldehyde can also be used for the determination if stored at 4 degrees C.

[Use of the Synpor membrane filter for the separation and determination of the number of somatic cells in the milk of dairy cows using the indole DNA filtration method]

The somatic cells of cow's milk were separated by filtering through nitrocellulose membrane filters (Synpor), pore size 2 to 5 micron. An indole reagent was added to the membrane filters with trapped cells, the mixture was warmed in boiling water bath for 20 min., then cooled, centrifuged (3500 X g, 15 min.), and optical density was measured at 490 nm. The relation 8 micrograms = 1 million cells was used for the conversion of DNA content in sample to the counts of cells. The average variation coefficient of the determination was 4.7% and the coefficient of correlation between the indole DNA filter method and direct microscopy on membrane filters was r = 0.997. Using the indole DNA filter method, the counts of somatic cells can be estimated from milk samples kept frozen or from filters with retained cells kept at 4 degrees C, or (for a short time--3 days) at 25 degrees C. The estimation is not distorted when the milk samples are stabilized with K2Cr2O7 or a mixture of K2Cr2O7 and HgCl2, if they are kept at 4 degrees C for eight days.

[Methods of diagnosing subclinical mastitis in dairy cow mastitis control programs]

The number of somatic cells and the isolation of the causative agents of mastitis in quarter, composite, bucket, and bulk tank samples of cow's milk was determined four times during a six-month period. The number of somatic cells in milk samples indicated a degree of mastitis infection and was influenced neither by the year season nor by the length of lactation. At a repeated examination of 28 dairy cows an increased number of somatic cells in milk was found once in 68 udder quarters and with three successive samplings only in 21 quarters. The etiological agents of mastitis were detected once in 31 quarters and three times in succession only in five quarters. The number of cows positive by the number of cells in quarter samples of milk increased from 52.9-58.8% at a single examination to as much as 100% at four examinations. The etiological agents of mastitis were isolated in a single examination in 17.6% of cows and at four examinations in 58.8% of cows. The composite and bucket samples of milk containing 200 to 300 thousand cells per ml are recommended to be considered as mastitis-positive: in 68 to 78% they came from cows having more than 500 thousand cells per ml at least in one quarter sample. The number of cells in a bulk sample was in correlation with the percentage of cows having a positive NK-test (similar to CMT) and positive isolation of S. agalactiae from quarter milk samples.(ABSTRACT TRUNCATED AT 250 WORDS)

[Incidence of foreign substances in raw and pasteurized milk]

In 1980 to 1982, the occurrence of inhibiting substances, herbicides and chemical elements contaminating raw farm and bulk milk and pasteurized milk in different stages of technological processing was studied in the input regions of 19 dairies of the Lacrum Brno concern corporation. Residues of inhibiting substances were demonstrated by the thin-layer microbiological diffusion disk method using the testing strain of B. stearothermophilus var. calidolactis, to be present in raw milk (9.1% out of 143 samples) as well as in pasteurized milk (2.0% out of 151 samples). Chromatographic method (sensitivity 0.01-0.05 mg.kg-1 milk) was used for examining 135 raw milk samples for the occurrence of herbicides based on diazines and triazines. Herbicides were demonstrated to get into milk; residues were found in 45 samples (33.3%). Atomic absorption spectrophotometry was used for examining 143 raw milk samples for the contents of zinc, copper, iron and manganese. As to zinc content, 100% of the samples met the standard, as to iron content 99%, and as to the content of copper, 89% (Ministry of Health Directives, No. 50, 1978). The content of manganese remained within the range up to 0.1 mg.kg-1 milk in 60% of the samples. Out of the 135 milk samples (101 raw, 34 pasteurized milk ones) examined for the content of lead, four samples (3%) failed to meet the limit of the highest admissible level.

The proportion of fatty acids in mammary secretion of cows lactating after calving and hormonal induction of lactation

The changes in the proportion of fatty acids in lacteal fat of cows induced into lactation by 7-day treatment with oestradiol and progesterone were characterized by an increases in the proportion of fatty acids C6--C13: the proportions of C14, C15, C17, C19 fatty acids changed slightly if at all; the proportions of C16, C20 and C22 fatty acids decreased during the first 28 days of lactation. Similar changes in fatty acid composition were found in lacteal fat of cows lactating after calving. These results demonstrated that the hormonal induction of lactation in nonpregnant cows initiates mammary secretion similar to the fatty acid composition in normal cow milk.

Hormonal control of casein synthesis in mammary explants from pregnant goats

The effects of insulin, cortisol, prolactin, 3,3',5-triiodo-L-thyronine (L-T3) and progesterone on the synthesis of total protein and casein in mammary explants from pregnant goats were studied. In the absence of hormones and in the presence of insulin plus cortisol the rate of incorporation of 14C-leucine into proteins that were precipitated with the anti-casein antibody decreased during culture. The addition of prolactin to hormonal combination of insulin and cortisol caused large stimulation of rates of casein synthesis. Maximum incorporation of leucine was attained between 3 and 5 days of culture in the presence of 0.5 microgram ml-1 of prolactin. Prolactin stimulated-casein and total protein synthesis were not consistently affected by the addition of L-T3 or progesterone. The inhibition of DNA synthesis by hydroxyurea or cytosine-arabinofuranoside had no effect on casein synthesis in mammary explants from pregnant goats.

Effect of progesterone, triiodothyronine and metabolic inhibitors on prolactin stimulated lipid synthesis in goat mammary explants

The effect of progesterone, 3,3',5-triiodo-L-thyronine (L-T3) and of inhibitors of DNA, RNA and protein synthesis on prolactin stimulated total lipid synthesis in goat mammary explants were studied. Prolactin stimulated lipid synthesis was not affected by the addition of progesterone. The synthesis of lipids in the presence of insulin, cortisol and prolactin was not stimulated by L-T3 (10(-9) mol 1(-1)) added at start of culture. However, when the addition of L-T3 was delayed by 48 h following culture with insulin, cortisol and prolactin, the synthesis of lipids was increased between 96--99 h of culture by 48%. This effect of L-T3 was blocked by the inhibition of RNA synthesis with actinomycin D. The inhibition of DNA synthesis by hydroxyurea or cytosine-arabinofuranoside had no effect on prolactin stimulated lipid synthesis in goat mammary explants. Actinomycin D, cycloheximide and puromycin completely blocked prolactin stimulated lipid synthesis when added to culture medium simultaneously with prolactin.

Effect of bovine growth hormone on development of goat mammary tissue in organ culture

The effect of bovine growth hormone (bGH) on DNA, protein and casein synthesis in goat mammary explants was studied. Growth hormone was unable to stimulate DNA synthesis or potentiate insulin-stimulated DNA synthesis either in high or low oxygen concentrations. In the presence of insulin and cortisol bGH had no effect on the synthesis of explant cytosol proteins. Two preparations of bGH were tested for their effect on casein synthesis. The preparation NIH-GH-B17 at concentration 50 micrograms ml-1 increased casein synthesis similarly as about 0.5 micrograms ml-1 of prolactin. Our preparation, prepared by the method of Prusík and Braun [1967], at concentration 50 micrograms ml-1 had effect lower than 0.05 micrograms ml-1 of prolactin. The lactogenic activity of NIH-GH-B17 was decreased by treatment with specific antisera to bovine prolactin. When submaximum concentration of prolactin (0.05 microgram ml-1) was added, bGH at concentration as low as 0.5 microgram ml-1 had synergistic effect on prolactin stimulated casein synthesis.

Changes in insulin and prolactin responsiveness of goat mammary tissue during ontogenesis and pregnancy

Mammary tissue of goats in different stages of ontogenesis and pregnancy were organ cultured and their insulin and prolactin responsiveness was studied. Based on the synthesis of DNA in the presence of insulin and tissue secretory responses to prolactin, the responsive tissues were found in young goats up to 3 month of age (prolactin responsive only up to 24 days of age), in mature virgin goats at the end of breeding season, mature virgin goats with precocious lactation and in nulliparous goats from the 8th week of pregnancy. Unresponsive tissues were found in goats from 4.5 month of age to the maturity. The high number of antral follicles in goat ovaries was found to be coincident with high mammary insulin and prolactin responsiveness during ontogenesis. It appears that ovarian and placental steroids and placental lactogen render the goat mammary tissue responsive to insulin and prolactin in organ culture.

Effect of estradiol and progesterone on udder growth in goats in vivo and lipid synthesis in goat mammary tissue in vitro

The effect of estradiol-17beta (E) and progesterone (P) and E, P and deprenon (D; an inhibitor of prolactin secretion) treatment on udder growth, colostrum-like formation and on the induction of lipid synthesis in mammary organ culture were studied. Administration of E and P for 8-14 days induced udder growth and colostrum formation. Intensive mammary growth and udder distention with secretion occurred following hormone treatment. Simultaneous administration of D prevented both udder growth and colostrum formation. In mammary explants from E, P and D treated goats the rate of incorporation 14C-acetate into lipids was increased by insulin (I), cortisol (F) and prolactin (M) as compared with the effect of I or I plus F. The tissue from placebo treated goats and goats treated with E and P responded to M either slightly or not at all. The high sensitivity of mammary tissue from goats treated with E, P and D to M was demonstrated immediately following the administration of E and P for 8 days and also 10 days after the treatment, but not 23 days following hormone administration.