Maceration stage in corrosion cast specimen procedure in anatomy: a minireview.

The etching stage of the corrosive preparation is a crucial element of creating a high quality anatomical specimen, which can be a source of scientific knowledge and support the teaching process. Nowadays, thermal techniques such as microwave cooking, enzymatic corrosion, and chemical corrosion are used. Living organisms can also be used for tissue maceration. Interactions between the corrosive substance and the filler carry a risk of failure; thus, choosing the correct method is key to the success of this technique. In this paper, we have reviewed the latest literature in order to present the strengths and weaknesses of currently used corrosion techniques. We proposed a definition of an ideal corrosive medium and compared the available techniques of etching corrosive preparations with a hypothetical perfect medium.

Epidemiology and impact of rotavirus diarrhoea in Poland.

Hospital and laboratory data were analysed in three hospitals to estimate rotavirus disease burden in 1994-96. Community acquired gastroenteritis was diagnosed in 757 children of whom 41% tested positive for rotavirus. A total of 196 children had rotavirus nosocomial infections (39% of all rotavirus community-acquired and nosocomial cases). Infants less than 24 months old and children less than 3 months old comprised 74% and 11.9% of admissions for rotavirus, respectively. Almost 94% of children with rotavirus infection had severe gastroenteritis (score > or =11). The annual rate of rotavirus associated hospitalization in Poland in 1996 was 3.1/1000 children under the age of 60 months and 5.2/1000 infants under 24 months of age. The mean hospital stay was 9.5 d (+/-9.8 d). We estimated that 8918 children under 60 months of age were hospitalized for rotavirus gastroenteritis in 1996; they accounted for 84899 inpatient days. We conclude that rotavirus is a leading aetiological agent of severe gastroenteritis in young children in Poland and that the burden of this infection is significant. Rotavirus vaccine could significantly decrease the hospitalization rate and the financial impact of rotavirus gastroenteritis in Poland.

Pre-exercise acidification induced by ingestion of NH4Cl increases the magnitude of the slow component of VO2 kinetics in humans.

UNLABELLED: Five healthy non-smoking men, aged 22.2 +/- 0.8 years (mean SD), VO2 max 50.2 +/- 6.2 ml.min-1.kg-1) performed two 6 minutes constant power output (PO) bouts of cycling at 70 rev.min-1, separated by a 20 minutes of rest. The power output during the first bout of exercise corresponded to 40% VO2max, while the second exercise corresponded to 75% VO2max. The first bout of exercise was performed at a power output below the lactate threshold (LT)--determined during an incremental exercise test. In the second bout of exercise the subjects exercised above the LT. This experimental protocol was performed twice. Once as a control test (test C) and on a separate day, at about 90 minutes after ingestion of 3 mmol.kg-1 BW of NH4Cl (test A). Ingestion of ammonium chloride developed a state of metabolic acidosis. Antecubital venous blood samples taken every one minute of cycling were analysed for pH, HCO-3, BE, pO2, pCO2 and plasma lactate concentration [La]pl. Oxygen uptake was measured continuously using breath by breath system. The obtained acidotic shift of blood acid-base balance was also present throughout the 6 minutes bouts of exercise. No significant difference in VO2 during the exercise corresponding to 40% VO2 max in the test C and the test A was observed. The total oxygen consumed throughout the 6 min cycling at the PO corresponding to 75% of VO2 max was not significantly different in test C and test A (13.532 vs. 13.422 l O2, respectively). The slow component of VO2 kinetics as expressed by the delta VO2(6-3 min) of exercise was significantly higher (p = 0.03) in test A than in test C (183 +/- 97 vs. 106 +/- 53 ml.min-1 O2, respectively). It should be noted that in each subject, the magnitude of the slow component of VO2 kinetics after pre-exercise acidification was consistently higher than in control experiment. IN CONCLUSION: The original finding of our study is that pre-exercise acidification induced by ingestion of 3 mmol.kg-1 B.W. of NH4Cl was accompanied by a significant increase in the magnitude of the slow component of VO2 kinetics. This is why we postulate that acidosis may play a significant role in the physiological mechanism responsible for the slow component of VO2 kinetics in humans.

Metabolic alkalosis induced by pre-exercise ingestion of NaHCO3 does not modulate the slow component of VO2 kinetics in humans.

Seven healthy physically active nonsmoking men, aged 22.4 +/- (SD) 1.8 years performed two 6 min bouts of cycling at 40% VO2max (sub-lactate threshold/low power output exercise) and 87% VO2max (supra-lactate threshold/high power output exercise) at 70 rev.min-1, separated by 20 minutes rest, on two occasions: once as a control experiment (test C) and on a different day at approximately 1.5 h after ingestion of 250 mg (3 mmol).(kg body weight)-1 of NaHCO3 (test A). At the onset of low and high power output exercise performed after ingestion of NaHCO3, antecubital venous blood pH and HCO3- were significantly elevated (p < 0.05). Moreover, blood pH and HCO3-, tested at every minute of low and high power output exercise, was significantly higher (p < 0.05) in test A than in test C. No difference was found in plasma lactate concentration [La]pl during low power output exercise between A and C tests. In the terminal phase of the high power output exercise (87% VO2max) the level of [La]pl rose more rapidly in test A than in test C, reaching in the sixth minute of cycling 8.27 +/- 1.11 and 6.76 +/- 0.68 mmol.l-1 (p < 0.01) in test A and C, respectively. No significant differences were found in the rate of VO2 measured breath-by-breath between A and C tests, both during low and high power output exercise. The slow component of VO2 kinetics (expressed by difference between VO2 measured at the 6th minute of exercise minus the VO2 reached at the 3rd minute), occurring only during exercise corresponding to 87% VO2, was not significantly different in C and A tests (0.373 +/- 0.050 and 0.339 +/- 0.078 1 O2, respectively). The total VO2 consumed throughout the six minute cycling at power output of 40 and 87% VO2max performed in control conditions and after ingestion of NaHCO3 was not significantly different. We have demonstrated that significantly reduced exercise acidemia accompanied by a significantly elevated level of [La]pl accumulation, did not affect the slow component of the VO2 kinetics and the magnitude of oxygen uptake during exercise corresponding to 40 and 87% of VO2max.

[Seminoma in extragonadal locations]. / Nasieniak w umiejscowieniu pozagonadalnym.

The pathogenesis, clinical picture and treatment of extragonadal seminoma are reviewed. For illustration a case is reported of a patient treated in the Regional Oncology Centre in Bydgoszcz.

Relation between smoking and levels of DDT and dieldrin in human fat.

The adipose tissue of humans with known patterns of cigarette smoking was collected during 1973-74 and analyzed for DDT components and dieldrin. Although smokers are exposed to high levels of insecticides from smoke of cigarettes and some of these compounds can be stored in adipose tissue, it could not be demonstrated that a relationship exists between smoking habit and residual levels of DDT found in fat. Smokers seem able, through induction of enzymes by substances in tobacco smoke, to metabolize these insecticides at a rate approximately equal to the rate of their intake in the smoke. Dieldrin residues in black male subjects were found to be linearly related to the number of cigarettes smoked, but the factors governing this relationship were not obvious.

Effects of weathering and flue-curing on methomyl residues on tobacco.

A replicated field experiment was conducted at two locations to determine the disappearance of methomyl from flue-cured tobacco. Immediately after application, methomyl residues were 88 and 113 ppm at Clayton and 44 and 105 ppm at Reidsville, respectively, for 0.56 and 1.12 kg/ha application rates. After 5 days these levels dropped to 0.7 and 2.8 ppm at Clayton and 1.4 and 4.1 ppm at Reidsville. At 9 days after application, 99% of the methomyl had disappeared at both locations. Losses of methomyl during flue-curing averaged 96% over locations, rates of application, and times of harvest, compared to an average loss of 98% due to weathering in the field for 5 days. The disappearance of methomyl during the curing process was approximately the same for both locations.

Hair and its associated lipids as an excretory pathway for chlorinated hydrocarbons.

1. Chlorinated hydrocarbon insecticides and other halogenated compounds, probably biphenyls, were found to be associated with human hair at concentrations less than 1 p.p.m. 2. In experiments with rats, chlorinated 14C-hydrocarbon insecticides and polychlorinated biphenyls were excreted in hair in all instances, but excretion was less with the more labile compounds. 3. Excretion via hair may be a significant factor in eliminating chlorinated hydrocarbons which resist metabolism.

Effects of weathering and flue-curing on monocrotophos residues on tobacco.

Disappearance of monocrotophos from flue-cured tobacco was studied at three locations (Kinston, Clayton, and Reidsville, North Carolina) in 1973. Average residues on green tobacco leaves collected immediately after application were 41 and 84 ppm, respectively, for application rates of 0.56 and 1.12 kg/ha. Levels declined to about 18 and 40 ppm for the two rates three days after application, to about 9 and 23 ppm at five days, and to about three and eight ppm at nine days. Conventional curing reduced residues on flue-cured tobacco by at least 99%.

Human subject experiments to estimate reentry periods for monocrotophos-treated tobacco.

Thirteen to fifteen human volunteers worked for eight-hr periods in tobacco fields treated 96, 72, and 48 hr previously with monocrotophos (3-hydroxy-N-methyl-cis-crotonamide dimethyl phosphate). At the 48-hr reentry period, during which time no rainfall occurred, both post-exposure plasma and red blood cell cholinesterase levels of the worker group were depressed from pre-exposure levels although the decline was less than 9% in both cases. Rainfall in excess of one inch fell during the 96- and 72-hr reentry intervals, and no important change in cholinesterase levels was noted. Experiments with mice were in general agreement with the human tests. Dimethyl phosphoric acid in urine of the worker group collected prior to, and three hr after, exposure was unchanged in all cases. Rain appeared to have markedly reduced dislodgable residues.