Hypothermia in Hodgkin's disease after exploratory laparotomy

Hypothermia is a rare complication of unknown origin in Hodgkin's disease which has been reported after the administration of antineoplastic agents, chlorpromazine and paracetamol. We report a highly febrile patient with stage IV-B Hodgkin's disease of mixed cellularity type who underwent exploratory laparotomy. Because of suspected septic shock high-dose prednisolone was given during surgery. Postoperatively the patient's body temperature fell progressively to 32.9 degrees C and remained at less then 35.5 degrees C for the following 5 days. There seems to be some functional disorder of thermoregulation in Hodgkin's disease. Physical factors during surgery or certain drugs, especially cytotoxics, corticosteroids, anesthetics or antipyretics may lead to prolonged hypothermia.

[Hemorheology and acute phase reaction following thrombendarterectomy of the extracranial carotid artery]

In 39 patients with hemodynamically significant stenoses of the internal carotid artery thrombendarterectomy was performed. Hemorheological properties and plasma protein levels were studied pre- and postoperatively over a period of 14 days. In comparison to age-matched healthy controls preoperative plasma viscosity, red cell aggregation, fibrinogen, haptoglobin and alpha-1-antitrypsin were significantly elevated. After surgical trauma there was an increase in fibrinogen, alpha-1-antitrypsin, haptoglobin and ceruloplasmin, whereas alpha-2-macroglobulin, immunoglobulin A and immunoglobulin G decreased significantly. Plasma viscosity, red cell aggregation, red cell filterability, fibronectin and immunoglobulin M remained unchanged. We conclude that our patients showed a non specific chronic "hematological stress syndrome" with raised acute phase reactants and corresponding hemorheological changes preoperatively; despite postoperative acute phase reaction no further deterioration of the rheological parameters could be observed; this might be caused by a decrease of plasma proteins with high frictional ratios compensating the increase of acute phase proteins. Besides, tissue damage and consecutive acute phase reaction in carotid arterial surgery seem to be of relatively minor degree.

[Endoscopic and surgical therapy of malignant colorectal polyps]

87 malignant colorectal polyps were removed in 81 patients by endoscopic polypectomy from 1972 until 1987. Thereafter 34 of these patients had a surgical resection of the colon. Surgical resection was performed for incomplete excision of the polyp (20 x), for tumor invasion of the lymphics in the polyp stalk and for moderately/poor differentiated carcinoma. In 6 patients a residual carcinoma was detected in the removed colon specimen, but lymph-node metastasis only in one with moderate-differentiated carcinoma. Our results demonstrate that colorectal polyps with invasive well-differentiated carcinoma and tumor free base do not need a surgical resection. Patients of the high-risk-group (moderately/poor-differentiated carcinoma, invasion of blood vessels and lymphatics, incomplete excision), should be referred to further surgical resection. With regard to the low rate of metastatic spread even in patients with high-risk-polyps accurate differentiation seems to be necessary. In 19 out of 52 (36.5%) patients endoscopic control examinations after surgical or endoscopic resection revealed recurrent pathological findings. On the base of the presented data we conclude that there is a need for short-term endoscopic controls over a period of five years.

Pharmacological characterization of the physostigmine stimulus in rats

Rats were trained to discriminate 0.10 mg/kg SC physostigmine from saline in a two-lever food-reinforced task. There was generalization to the acetylcholine esterase inhibitor THA as well as to the muscarinic receptor agonists arecoline, oxotremorine and RS 86, but not to neostigmine or nicotine. The physostigmine cue was blocked by SC scopolamine hydrobromide and by ICV pirenzepine, but not by scopolamine methylbromide or by mecamylamine. These antagonism studies suggest that the discriminative cue elicited by physostigmine might be mainly mediated by central M1 receptors.

Characterization of the scopolamine stimulus in rats

The discriminative stimulus properties of scopolamine, a potent antagonist at muscarinic receptors, were used for testing the discriminative effects of drugs known to act on cholinergic transmission. Rats were trained in a standard two-bar operant conditioning procedure with food as the reinforcer, according to a FR10 schedule. The training dose of scopolamine was progressively reduced from 0.25 mg/kg SC to the low dose of 0.062 mg/kg SC. Scopolamine yielded an accurate discrimination in all the six rats tested. The generalization gradient resulted in an ED50 of 0.027 mg/kg. The scopolamine cue lasted for 1 h and was of central origin, since it was not mimicked by scopolamine methylbromide. The scopolamine stimulus generalized to atropine and trihexyphenidyl (respective ED50 values 2.20 and 0.21 mg/kg SC). Atropine depressed rate of responding, while trihexyphenidyl did not. Antagonism experiments with both direct agonists at the muscarinic receptor (arecoline and oxotremorine) and indirect agonists, i.e., inhibitors of the acetylcholine esterase [physostigmine and tetrahydroaminoacridine (THA)], led to inconsistent results. Increasing the doses of the agonists in order to block the scopolamine cue may be limited by their rate suppressant effect on responding. Based upon previously published results, it is suggested that the muscarinic agonist cue is more useful than the antagonist cue for investigating muscarinic transmission.

Effects of intracerebroventricular pirenzepine on muscarinic discriminations in rats

In rats, mixed M1/M2 muscarinic ligands induce a discrimination which is of central origin and selectively mediated by either one or both muscarinic receptor subtypes. In the present study we examined the effects of intracerebroventricular (i.c.v.) pirenzepine, a relatively selective M1 receptor antagonist which does not cross the blood-brain barrier, on muscarinic discriminations. Groups of six rats were trained to discriminate, in a two-lever operant task, either 0.062 mg/kg subcutaneous (s.c.) scopolamine or 0.075 mg/kg s.c. oxotremorine. When the rats had been well trained in the procedure, the discriminative effects of various i.c.v. muscarinic ligands were examined. Scopolamine (1.5-12 micrograms i.c.v.), but not pirenzepine (20-40 micrograms i.c.v.), generalized to s.c. scopolamine. Oxotremorine (0.75-6 micrograms i.c.v.) generalized to s.c. oxotremorine. Scopolamine (12 micrograms i.c.v.), but not pirenzepine (20-40 micrograms i.c.v.), antagonized the oxotremorine cue. These results suggest that activation of the M1 receptor is not the prominent component of muscarinic stimulus control.

Discriminative stimulus properties of muscarinic agonists

In a two-lever, food-reinforced drug-discrimination paradigm separate groups of rats were trained to discriminate either arecoline, pilocarpine or oxotremorine from saline. The discriminative cues of all three agonists were potently blocked by scopolamine, but only by 30-60 fold higher doses of methylscopolamine. The three agonists all suppressed overall response rate. These rate-suppressant effects were not blocked by scopolamine in doses which blocked the discriminative cues. In generalization tests, arecoline elicited selection of the drug-appropriate lever in all groups of trained animals. Pilocarpine was discriminated as drug by all pilocarpine-trained animals and by a majority of oxotremorine-trained animals, but was not significantly discriminated by the arecoline-trained group. Oxotremorine was discriminated by all oxotremorine-trained animals but only by some pilocarpine-trained animals, and was not significantly discriminated by the arecoline-trained group. Morphine, haloperidol, chlordiazepoxide, pentobarbital and nicotine were not generalized to any of the training drugs. The discriminative stimuli produced by the training drugs are therefore specific and exhibit properties indicative of an origin at central muscarinic receptors but may not be identical.

Stimulation of T cells by autologous mononuclear leukocytes and epidermal cells in psoriasis

Based on reports suggesting aberrant cell-mediated immunity and altered infiltration of immunocompetent cells into the skin in psoriasis, we studied the stimulation of T cells by autologous non-T mononuclear leukocytes (autologous mixed lymphocyte reaction, AMLR) and by epidermal cells isolated from lesional and clinically uninvolved skin in psoriasis (autologous mixed epidermal cell lymphocyte reaction, AMECLR). Age- and sex-matched individuals served as controls. We found that the AMLR in psoriasis (n = 11) was similar to that in healthy controls (n = 16); furthermore, cell proliferation was alike in the presence of either 5% AB-serum or autologous serum. By contrast, while the AMECLR in healthy controls (n = 9) resembled that in psoriatics employing epidermal cells from univolved skin, epidermal cells from lesional sites (n = 10) induced a significantly higher proliferation of autologous T cells in the AMECLR (P less than 0.01). We conclude that the in vitro stimulation of T cells by non-T mononuclear leukocytes is normal in psoriasis and is not regulated by autologous serum. Lesional psoriatic epidermal cells, however, are more active in stimulating autologous T cell proliferation than cells from univolved psoriatic or normal epidermis.

Codon-induced association of the isolated anticodon loop of tRNAPhe

The binding of the codon UUC to the isolated anticodon loop of tRNAPhe (yeast) has been studied as a model of codon recognition by a simple adaptor. Fluorescence titrations demonstrate that UUC binds to the isolated anticodon loop with an equilibrium constant of 1.4 X 10(3) M-1 (at 7.2 degrees C). Equilibrium sedimentation curves reveal that UUC binding induces association of anticodon loops beyond the dimer stage. A set of complete sedimentation curves obtained for various reactant concentrations was analyzed according to a model with an infinite number of subsequent association steps for UUC-anticodon loop complexes and with equal affinity for each step. The coupling of association and sedimentation was considered quantitatively, and the information resulting from conservation of mass was used by integration. According to this procedure, the experimental data can be described by an isodesmic association constant of 8 X 10(3) M-1 with satisfactory accuracy. Temperature-jump relaxation detected by fluorescence measurements provides independent evidence for codon-induced association of the anticodon loop. The data are consistent with the following mechanism: UUC preferentially binds to one of two loop conformations with a rate constant of 4.5 X 10(6) M-1 s-1; the UUC-anticodon loop complex undergoes association with a rate constant of 6.5 X 10(6) M-1 s-1. The reactions observed for the isolated anticodon loop are surprisingly similar to those observed previously for the complete tRNA, suggesting that simple hairpin loops are appropriate adaptors for a translation process at an early stage of evolution; the codon-induced association of the hairpin loop should be very useful to facilitate the transfer of cognate amino acids during translation.

[New aspects of early gastric carcinoma]

Between 1st January 1970 and 31st December 1984, 910 total or subtotal resections for gastric cancer were carried out in the Department of Surgery of the University Clinic Mannheim. A work-up of operative specimens showed that 146 patients (16%) had early gastric carcinoma. The patients comprised 97 men and 49 women; the youngest was 31, the oldest 86 years. The following trends were apparent when the 58 patients operated on between 1970 and 1976 were compared with the 68 patients operated on between 1977 and 1982: An increase in early gastric carcinoma is also detectable in younger patients. The previously seen tendency for localisation in the antrum appears to have changed in favour of the upper segments of the stomach. The proportion of the diffuse type rose from 26% in the first group to 44% in the second. The 5-year survival of all patients with early gastric carcinoma was 78.8%. No significant difference could be found between the diffuse and intestinal type. The prognosis of early gastric carcinoma appears to be dependent on the depth of invasion and involvement of the lymph nodes.

The conformation of single stranded oligonucleotides and of oligonucleotide-oligopeptide complexes from their rotation relaxation in the nanosecond time range

The conformation of single stranded oligonucleotides is analysed by measurements of their rotation time constants. The oligomers are aligned to some degree by short electric field pulses; after pulse termination the transition to a random orientation is followed by measurements of the linear dichroism. An efficient deconvolution procedure is developed for evaluation of the experimental data obtained in the ns-time range. The increase of rotation time constants observed for chain lengths in the range from 14 to 22 residues are interpreted according to a weakly bending rod model providing a persistence length and a Stokes' diameter. The Stokes' diameters obtained for ribo- and deoxyriboadenylates are about 13A, in approximate agreement with the expectation for a single stranded helix. The persistence length L = 53A corresponding to approximately 16 nucleotide residues found for riboadenylates at 2 degrees C appears to reflect relatively strong stacking interactions at this temperature. However, a comparison with the average length of stacked residues evaluated from available thermodynamic parameters of base stacking indicate that unstacked residues are not completely flexible. Apparently the ribose-phosphate chain provides an essential contribution to the stiffness of oligomers and polymers, even when the bases are unstacked. Addition of 100 microM Mg2+ leads to an increase of the persistence length to 88A. Corresponding measurements with deoxyriboadenylates show a slightly lower value of the persistence length than that found for riboadenylates. Addition of LysTrpLys and LysTyrLys to A(pA)19 leads to an increase of the rotation time constant, which corresponds approximately to a length increment by one residue per bound peptide. Since controls performed with LysLeuLys do not show any similar effect, the increase of the time constants induced by LysTrpLys and LysTyrLys is attributed to intercalation of the aromatic amino acids.

Concordance of experimentally mapped or predicted Z-DNA sites with positions of selected alternating purine-pyrimidine tracts

The recent electronmicroscopic and biochemical mapping of Z-DNA sites in phi X174, SV40, pBR322 and PM2 DNAs has been used to determine two sets of criteria for identification of potential Z-DNA sequences in natural DNA genomes. The prediction of potential Z-DNA tracts and corresponding statistical analysis of their occurrence have been made on a sample of 14 DNA genomes. Alternating purine and pyrimidine tracts longer than 5 base pairs in length and their clusters (quasi alternating fragments) in the 14 genomes studied are under-represented compared to the expectation from corresponding random sequences. The fragments [d(G X C)]n and [d(C X G)]n (n greater than or equal to 3) in general do not occur in circular DNA genomes and are under-represented in the linear DNAs of phages lambda and T7, whereas in linear genomes of adenoviruses they are strongly over-represented. With minor exceptions, potential Z-DNA sites are also under-represented compared to random sequences. In the 14 genomes studied, predicted Z-DNA tracts occur in non-coding as well as in protein coding regions. The predicted Z-DNA sites in phi X174, SV40, pBR322 and PM2 correspond well with those mapped experimentally. A complete listing together with a compact graphical representation of alternating purine-pyrimidine fragments and their Z-forming potential are presented.

Structural family therapy: its application to Chinese families

In summary, it can be stated that structural family therapy, for a variety of reasons, offers an appropriate treatment model for dysfunctional Chinese families. Since the family, not the individual, is the more important unit in Chinese culture, the model offers the opportunity for the total family to participate in changing dysfunctional individual and family patterns. The model focuses upon structure, which is the essence of the Chinese family. In addition, it is problem- and growth-oriented, creates a nondefensive atmosphere in which family members can change, and works toward helping family members improve communication and modify behavior. It is important to stress that it does not focus upon helping family members make significant changes in their value system. Furthermore, the model can be applied to most problem areas, because it is assumed that the presenting problem is reinforced by family structure and repetitive patterns. Consequently, family interactional patterns that reinforce the presenting problems are the major focus of the treatment. Finally, the model allows for the utilization of theories and practice principles of other clinical approaches. Structural family therapists assume the role of authority figures who are experts in family therapy. They view the family within the context of its environment, are sensitive to the cultural norms of the group with which they are working, and utilize supportive services as an integral part of treatment. More important, therapists believe in the power of families to make changes and work toward helping them become involved in a new process of interaction that will lead to satisfactory changes.

[Implantation of ultra thin naso-duodenal and naso-jejunal tubes for feeding]

Enteral nutrition through filiform naso-duodenal or naso-jejunal tubes with homogeneous low molecular nutritional solutions has a rather important place in therapy of different conditions; endoscopy can help to introduce these tubes into the intestinal tract in the following situations: A leak in the upper gastrointestinal tract, which may occur after surgical resections of the esophagus or stomach, or which may occur in rare cases after bouginage or after diagnostic procedures can be passed by with an ultrathin tube until it is healed of. Patients with stenotic lesions of the esophagus or the cardia, which can not be treated by surgery or conservative procedures like pertubation and dilation can be fed enterally if it is possible to move the tube beyond the stenosis. Patients with neurogenic swallowing dysfunction of different origine can be fed during long periods of time through such filiform naso-enteral tubes successfully and reach a perfect nutritional state. In acute treatment of Crohn's disease and other inflammatory intestinal diseases enteral nutrition through tubes is an essential therapeutic procedure.

[Poisoning with clonidin hydrochloride in children and adults]

In this study clinical findings are presented of 31 patients with clonidinee intoxication and the therapeutic measures taken in these cases are discussed. In toddlers poisoning is seen after ingestion of a single tablet of 150 micrograms clonidine, whilst in adults poisoning may occur already at a dosage just exceeding the therapeutic limit, which is subject to wide individual variation (1 to 3 tablets). Primary elimination procedures must be instituted at these dosages, but, because of the rapid absorption of clonidine, gastric lavage and induced emesis provide no benefit to patients with complete symptomatology or those who took the overdose several hours before. Chlorpromazine-like effects, hypotension and bradycardia proved to be the outstanding features. Respiratory depression, disturbances of myocardial conduction or hypertension were less frequent. Symptoms lasted for a mean of 15.5 +/- 8.6 hours, with a range of 4 to 36 hours. Fluid therapy and, as necessary, dopamine for hypotension, phentolamine for hypertension and atropine for bradycardia caused prompt improvement in addition to essential measures such as meticulous control of respiratory function, body temperature and of ECG changes. There was no need to implement the central clonidine antagonist, tolazoline in any of these cases.

Inhibition of histamine biosynthesis and gastric function in the rat: effect on pentagastrin-induced gastric acid secretion

A very simple and rapid method to measure gastric acid secretion in the conscious unoperated fasted rat is reported. Antisecretory activity of cimetidine and hypersecretory activity of pentagastrin are detected by this procedure. Pentagastrin induces gastric acid secretion and causes an increase by 2-fold in histidine decarboxylase activity. There is a delay between the increase of gastric acid output and the appearance of histidine decarboxylase activity. Co-administration of monofluoromethyl histidine, a specific irreversible inhibitor of histidine decarboxylase, does not modify the peak response to pentagastrin but shortens the duration of stimulation. We suggest from this data that histamine biosynthesis is needed for maintenance of elevated gastric acid secretion.

Stability decrease of RNA double helices by phenylalanine-, tyrosine- and tryptophane-amides. Analysis in terms of site binding and relation to melting proteins

The amides of L-phenylalanine, L-tyrosine and L-tryptophane decrease the melting temperatures tm of poly(A)*poly(U) and poly(I)*poly(C) double helices at low concentrations (1 mM), whereas high concentrations finally lead to an increase of tm. This dependence of the tm-values upon the ligand concentration can be represented quantitatively by a simple site binding model, providing binding parameters for the interaction between the amides and the nucleic acids both in the double- and the single-stranded conformation. According to these data the affinity to the single strands is higher than that to the double strands and increases in the series Phe less than Tyr less than Trp. The binding constants decrease with increasing salt concentration as expected for an interaction driven by electrostatic attraction. However, part of the interaction is also due to stacking between the aromatic amides and the nucleic acid bases. The present results indicate a direct correlation between the presence of aromatic amino acids at the binding site of helix destabilising proteins and the properties of simple derivatives of these amino acids. Furthermore the results suggest that very simple peptides containing aromatic amino acids served as a starting point for the evolution of helix destabilising proteins.

Electric properties and structure of DNA-restriction fragments from measurements of the electric dichroism

The electric dichroism of 17 homogeneous DNA fragments, ranging in size from 43 to 4362 base-pairs, has been analyzed in high electric fields. The orientation of the small fragments can be described in terms of an induced dipole moment, whereas the large fragments are oriented according to a constant dipole mechanism. In the intermediate size range, DNA orients according to an induced dipole mechanism at low field strengths and according to a constant dipole mechanism at high field strengths. From these observations we propose an orientation mechanism with a saturating induced dipole. The induced dipole observed at low field strengths is saturated at a field strength Eo within a transition range Em to give a constant dipole moment at high field strengths. These parameters together with the polarizability and the limit reduced dichroism are evaluated by a least-squares analysis of the experimental data. Eo and Em are found to decrease with increasing chain length from Eo approximately 40 kV/cm (Em approximately 14 kV/cm) at 65 base-pairs to 10 kV/cm (6 kV/cm) at 194 base-pairs. The polarizability is found to increase with the square of the chain length, whereas the saturated dipole increases with chain length N at low N and goes to a limit value at high N. The temperature dependence of the orientation parameters is found to be very small. The values obtained for the limit dichroism are between -1.0 and -1.3 for chain lengths between 60 and 1000 base-pairs, whereas values around -1.4 are observed at chain lengths greater than 1000 base-pairs. These data indicate that electric fields extend the contour of DNA strands at high chain lengths from a weakly bent to a more linear form. The variations of the limit dichroism observed for short fragments suggest sequence-dependent differences in the secondary structure of the helix. The experimental results are compared with numerical calculations based on simple polyelectrolyte models. For short fragments the magnitude of several electrochemical parameters can be adequately explained by a polarization of the ion cloud around the DNA molecules. However, these polyelectrolyte models do not adequately describe the observed chain length dependence of the orientation phenomena.

[Serodiagnosis of human Yersinia infections. Preliminary results]

Preliminary data are reported on experience with newly developed complement-fixing (CF) antigens prepared from cultures of type 3 and type 9 Yersinia enterocolitica and from Yersinia pseudotuberculosis. Antigens were immunologically potent and not anti-complementary, thus making it possible to obtain satisfactory serologic tests. The results may be summarized as follows: 1. Yersinia CF antigens do not react with sera from healthy blood donors. There was only one low titer reaction with type 9 antigen among more than 300 serum samples tested. 2. There was a high degree of correlation between results of the agglutination tests and those obtained by CF. 3. There is no cross-reactivity by CF among the three Yersinia antigens if human sera are tested. A complete crossing was, however, obtained between type 9 Yersinia and Brucella abortus. 4. Hyperimmune sera frequently showed marked cross-reactivities in both CF and agglutination tests. 5. Human sera positive for various Salmonellae do not react in the CF tests with Yersinia antigens. It is felt that the new CF antigens may become an important tool for the detection of antibodies against Yersinia enterocolitica in the diagnosis of infectious diseases.

Recent biosynthetic studies on beta-lactam antibiotics

Recent experimental observations on the cell-free formation of penicillins and cephalosporins in protoplast lysates from C. acremonium are described. Conversion of radiolabelled penicillin N into deacetoxycephalosporin C is described. A proposal is made about the general types of mechanism involved in these conversions.

[Angiographic examinations in hypertension. Vascular morphology, flow rate and kidney size (author's transl)]

1. The paper reports on examinations relating to vascular morphology, flow rate and kidney size in patients suffering from arterial hypertension. 2. The results and findings differ clearly from those of the total group of patients and a control group of healthy volunteers. 3. The results and observations are discussed. 4. Renal angiography can give more information than commonly assumed. Hence it should be employed more frequently than before for the purpose of clarifying diagnosis in patients with arterial hypertension.

[Physically handicapped pupils at a regular school - experiences of the school experiment "Lichtenau" (author's transl)]

As an experiment in integration, the joint placement of physically handicapped and non-disabled pupils into the regular class settings of a school belonging to the Hessisch-Lichtenau experiment makes special social and educational measures necessary both at school and in the residential home. The main activities have to be directed towards scientific studies of existing problems and their practical solutions. The following article describes the problems arising from the integrational efforts and suggests possible solutions.

[Marrow scintigraphy in Paget's disease of bone (author's transl)]

Marrow scintigraphy using 99mTc colloids was performed in 20 patients with Paget's disease of bone and compared with skeletal scanning in each of them. As long as the regions explored were haematopoietically active, despite the advanced age of the patients, there was decreased marrow uptake in regions of increased uptake on the skeletal scan. Whilst increased uptake of pyrophosphate reflects bone hyperosteogenesis, decreased uptake of colloids reflects marrow fibrosis, and early histological sign of the disease. This scanning technique could be a new criterion in the surveillance of the therapeutic effectiveness of calcitonins or of diphosphonates.

Analogues of ornithine as inhibitors of ornithine decarboxylase. New deductions concerning the topography of the enzyme's active site

Fourteen structural analogues of ornithine were synthesized and evaluated as inhibitors of preparations of the enzyme L-ornithine carboxylase (ODC) (E.C. 4.1.1.17) obtained from rat liver, rat hepatoma cells in culture, or bull prostate. The synthesis of these compounds was achieved either via a Bucherer type reaction or via alkylation of carbanions derived from ethyl acetamidocyanoacetate, methyl isocyanoacetate, benzyl alpha-isocyanopropionate, methylbenzaldimine alanate, and the azlactone derivative of ornithuric acid. (+)-alpha-Methylornithine, which was assigned the L configuration on the basis of rotational criteria, was found to be the most potent reversible inhibitor of ODC among the synthesized compounds. From the degree of inhibition of ODC activity in the presence of the various ornithine analogues, it has been possible to delineate some of the structural features of the substrate L-ornithine which are required for binding to the mammalian ODC active site.

Acid-base balance and blood gases changes and "lactate excess" in acute respiratory alkalosis during general anaesthesia

In 40 young males aged 18-20 years operated on for inguinal hernioplasty acute respiratory alkalosis was obtained in the 45th minute of general anaesthesia. The values of basic acid-base balance parameters, blood gases, pyruvate and lactate levels and "lactate excess" were determined before and after hyperventilation. Shifts in the concentrations of hydrogen and bicarbonate ions were found which are both typical of acute respiratory alkalosis. No changes were observed in the oxygenation of capillary blood and the values of "lactate excess" were normal which rules out tissue hypoxia during acute respiratory alkalosis. Passive hyperventilation being a less dangerous alternative of hypoventilation is a frequent occurrence during general anaesthesia and it causes transient respiratory alkalosis.