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Human spatial memory can be divided into multiple, partly separate cognitive processes. In this study, object location memory was studied using a set of tasks that assessed three different spatial memory aspects: positional memory, object location binding, and a combined process. Also, maze learning and spatial span memory were measured. Ten patients who had undergone intracranial tumour resection participated, and their individual results were compared with control data from 24 healthy subjects. Four patients showed selective spatial memory impairments; two patients were impaired at positional memory, and two other patients were impaired on object location binding and the combined process. This double dissociation provides further evidence for the notion that object location memory is not a unitary system, but consists of at least two separate mechanisms. In addition, spatial memory problems were predominantly present in the patients with lesions in either the right hemisphere or in the parietal lobe. These results are in agreement with previous findings on the involvement of the right hemisphere and the posterior parietal cortices in spatial processing.

Circulating levels of growth hormone (GH) change during the process of aging. Decline of cognitive functioning with aging is also well established. In this study, we investigated whether insulin-like growth factor 1 (IGF-1) and the GH response to a challenge of GH-releasing hormone and GH-releasing peptide 6 were associated with age-sensitive cognitive functions, but not with functions that do not decline with aging, in 17 healthy male subjects aged between 66 and 76 years. In addition, relations with anthropometric measures were examined. Neuropsychological performance was scored on tests of variables not sensitive to aging (general knowledge, vocabulary, basic visual perception and reading ability), and of variables sensitive to aging (visuoconstructive ability, perceptual motor and mental processing speed, and verbal long-term memory). After correcting for education, the serum GH response was significantly associated with two age-sensitive cognitive tests (measures of mental processing speed), but with none of the tests not sensitive to aging. However, the direction of the association was opposite to the relation between IGF-1 and these cognitive tests: higher levels of GH response were associated with poorer cognitive performance, whereas higher levels of IGF-1 were associated with better performance. GH response, but not IGF-1, was inversely correlated with body mass index. The results are in accordance with previous research suggesting a disruption of the relation between IGF-1 and GH secretion in older age.

Homozygotes for the rare folate-sensitive autosomal fragile sites have never been recorded. Two non-folate-sensitive rare fragile sites (FRA10B and FRA17A) have been previously recorded in normal individuals. We document two unrelated normal individuals who are homozygotes for the rare fragile site FRA16B and record the patterns of induction of this fragile site with berenil. The existence of normal homozygotes for FRA16B suggests that this fragile site is not within a gene essential for normal development.

Three patients with accessory small ring chromosomes derived from chromosome 1 are presented together with additional clinical details and cytogenetic analyses of a previously reported patient. Cytogenetic analysis was undertaken by FISH using a reverse painting probe generated from one of the patients by microdissection of the r(1) chromosome and with a BAC923C6 which maps to 1p12. Results indicated that patients with r(1) chromosomes consisting of 1q12 heterochromatin and short arm pericentric euchromatin which extends to at least the BAC923C6 were associated with a normal or mild phenotype. Patients with abnormal phenotypes possessed two types of rings. One patient had evidence for contiguous pericentric short arm euchromatin which extended from the centromere to beyond the BAC923C6. Two patients showed molecular cytogenetic results which were compatible with non-contiguous chromosome 1 euchromatin. The diversity of origin of r(1)s will hamper attempts to define phenotype/genotype relationships. Keywords: ring chromosome 1; microdissection; chromosome painting

We describe a 14-year-old male with dissection of the descending aorta, bilateral iris hypoplasia, striae distensae and brachytelephalangy, the latter being most marked in the thumbs. Inguinal herniae and a patent ductus arteriosus were surgically repaired in infancy. The pattern of abnormalities may constitute a previously undescribed syndrome. The proband died suddenly at the age of 17 years.

In order to control the quality of rare earth determinations in environmental matrices, the Standards, Measurements and Testing Programme (formerly Community Bureau of Reference, BCR) of the European Commission has started a project, the final aim of which is to certify four types of matrices (tuna muscle, mussel tissue, aquatic plant and estuarine sediment) for their contents of a range of rare earth elements (Sc, Y and the lanthanides: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The elements U and Th were added to the study. The first part of this project consisted of an interlaboratory study which aimed to test the feasibility of preparation of environmental reference materials and to detect and remove most of the pitfalls observed in rare earth determinations. This paper presents the preparation of the four matrices for the intercomparison study and for the candidate reference material. The main results are presented of the interlaboratory study that was carried out prior to the certification campaign. This collaborative trial is the first attempt ever carried out at this scale to evaluate the state-of-the-art of rare earth determinations in the environment. Its impact on the improvement of chemical measurements will have positive effects on the comparibility of data necessary for environmental monitoring.

This study was conducted to examine the relationship between baseline salivary cortisol (CORT) levels and selective attention for displays of angry faces. Selective attention was investigated using a pictorial emotional Stroop task, comparing colournaming-speed of angry and neutral faces. The task was assessed in supraliminal (unmasked) and subliminal (masked) conditions to 28 non-clinical subjects (14 male and 14 female). Repeated measures analysis of variance revealed a significant interaction between median split CORT levels (low vs. high) and masked face valence (angry vs. neutral). The latter effect was mainly due to significant facilitation in the high CORT subject-group; these subjects seemed to allocate their attention away from the masked angry face. A relation between baseline CORT levels and fast withdrawal behavior is suggested.

OBJECTIVES The long term outcome after a single symptomatic lacunar infarct may be less favourable than is generally assumed. Patients often present with complaints such as fatigue or “being different from before the stroke”, for which there are no obvious physical explanations. Although cognitive functioning is considered normal in most patients with lacunar infarction in the internal capsule or corona radiata, a study was carried out to determine if subclinical changes in mental or emotional function can explain these vague complaints characteristic for their disablement. METHODS Sixteen patients, each with a single symptomatic supratentorial lacunar infarct, and 16 matched healthy controls were examined with an extensive neuropsychological screening battery and a standardised questionnaire aimed at emotional problems. The mean number of correct responses was calculated for each subject and averaged within each group. RESULTS Although, on the whole, there were no differences in performance, patients’ results on the following tasks in different modalities showed evidence for decreased performance under relatively more demanding conditions: line orientation task (mean difference (MD) 261 ms; 95% confidence interval (95%CI) 94 to 428), Rey-Osterrieth delayed recall (MD−3.8, 95% CI −7.5 to 0.0), visual elevator subtest of the everyday attention task (EAT) (MD −0.7, 95% CI −1.5 to 0.1), lottery subtest of the EAT (MD −0.6, 95% CI −1.3 to 0.1) and WAIS similarities (MD −3.2 95% CI −6.3 to 0.1). Patients also more often had emotional disturbances than controls. CONCLUSION Both subtle cognitive impairments and emotional disturbances may play a part in the decreased competence in everyday life of patients with a supratentorial lacunar infarct.

In this study, follow-up results of cognitive-behaviour therapy and of a combination of cognitive-behaviour therapy with a serotonergic antidepressant were determined. The study also examined factors that can predict this treatment effect, both in the long term and in the short term. In addition, it investigated whether differential prediction is possible for cognitive- behaviour therapy vs. a combination of cognitive-behaviour therapy with a serotenergic antidepressant. A total of 99 patients were included in the study. Treatment lasted 16 weeks, and a naturalistic follow-up measurement was made 6 months later. Of the 70 patients who completed the treatment, follow-up information Was available for 61 subjects. Significant time effects were found on all outcome measures at both post-treatment measurement and follow-up. No differences in efficacy were found between the treatment conditions. Effectiveness at post-treatment measurement appears to predict success at follow-up. However, 17 of the 45 non-responders at the post- treatment measurement had become responders by the follow-up. The severity of symptoms, motivation for treatment and the dimensional score on the PDQ-R for cluster A personality disorder appear to predict treatment outcome. No predictors were found that related specifically to cognitive-behaviour therapy or combined treatment. These results indicate that the effectiveness of cognitive-behaviour therapy or a combination of cognitive-behaviour therapy and fluvoxamine at the post-treatment measurement is maintained at follow-up. However, non-response at post-treatment does not always imply non- response at follow-up. Patients with more severe symptoms need a longer period of therapy to become responders. Although predictors for treatment success were found, no evidence was found to determine the choice of one of the treatment modalities.

We describe the clinical, histopathologic, and angiographic findings in four children with congenital abnormalities of the great vessels of unknown cause, comprising either single or multiple arterial aneurysms, aortic/arterial dilatation, vessel tortuosity, or combinations of these abnormalities. Two children had early and severe respiratory distress due to aneurysmal compression of the trachea. All children had diffuse dilatation of several arteries, and two children also had tortuosity of multiple arteries. Progression of these abnormalities was clearly evident in one child, in whom diffuse vessel irregularity and tortuosity affected intra-abdominal, and intra and extra-cranial arteries. One child died at 5 years, while the other three have undergone successful surgical repair in the first 3 months of life and are now well, between age 2.5 and 7 years. The phenotype of each child appears unique but all have in common the rare finding of aneurysms of the aorta and main pulmonary artery. Congenital aortic aneurysms did not occur as an isolated finding in any of these children.

The concept of agnosia as a higher order functional impairment, which can occur in the absence of low level visual perceptual deficits, continues to provoke debate. This controversy is complicated by the fact that, on close examination, agnosic patients do tend to have some perceptual difficulties. Thus the issue centres around the question as to whether these deficits play a causal part in the aetiology of agnosia or whether they are functionally independent, with both impairments resulting from the substantial cerebral lesions involved in agnosia. In 1956, Ettlinger published a study in which he compared the performance of patients with visual recognition deficits and patients with posterior brain lesions whose recognition abilities were intact. He argued that visual perceptual problems could not explain the recognition deficit in agnosia as he saw far worse perceptual impairments in patients who did not experience any problems in visual recognition. Although the logic of Ettlinger9s argument is not disputed, some criticisms have arisen concerning the study, such as the fact that his experimental group did not include a truly object agnosic patient. In addition, Ettlinger9s visual-sensory assessment can no longer be considered comprehensive in the light of present day knowledge of the cerebral visual apparatus. This study therefore investigated three (prosop)agnosic patients and five patients with unilateral brain lesions without recognition deficits on an extensive battery of visual sensory tests. The results support Ettlinger9s original claim that (in some cases) agnosia cannot be explained as resulting from lower level visual impairments.

The case is reported of a baby boy with an interstitial deletion of the long arm of chromosome 13 who, in addition to the described associations of Hirschsprung9s disease and intestinal atresia, had umbilical cord ulceration resulting in massive intrapartum haemorrhage. This case provides support for the existence of a previously reported association between umbilical cord ulceration and intestinal atresia, and suggests that it is aetiologically heterogeneous.

A 9-year-old girl with craniosynostosis, facial dysmorphism, mental retardation, proportionate short stature and acral abnormalities is described, in whom both clinical and radiological features support a diagnosis of Hunter-McAlpine syndrome. Her mother is mildly affected, confirming previous evidence that this syndrome is dominantly inherited and shows considerable phenotypic variability within families.

Zinc in plasma and urine and serum albumin and alpha 2-macroglobulin were measured in 48 patients with burns. Mean total burned surface area amounted to 18%, ranging from 2 to 55%, and mean hospitalization time amounted to 35 days, ranging from 10 to 124 days. All parameters showed a decrease during the first two post-burn days. Minimal values were reached on days 2 and 3 for plasma and urine zinc, and between days 5 and 10 for the proteins. Thereafter, values increased, rapidly for both plasma and urinary zinc, more slowly for albumin and alpha 2-macroglobulin. The ratio R of the total plasma zinc minus the alpha 2-macroglobulin concentration to the albumin concentration is postulated as an indicator for zinc deficiency. From values of R and of the urinary zinc excretion, conclusions can be drawn about various processes of the zinc metabolism that may occur during the acute stage following the thermal accident and during the stages of tissue demarcation and of recovery. These processes are discussed in terms of possible temporary and/or local zinc deficiency. Evidence is presented that zinc administration in only indicated during the final stages of recovery in case of inadequate dietary intake.

To present the first reported Australian case of prenatal treatment of a female fetus with congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency.A couple whose son had congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency sought prenatal diagnosis and treatment in their next pregnancy.Maternal treatment with dexamethasone was commenced at seven weeks' gestation to suppress androgen production by the fetal adrenal glands and prevent virilisation of an affected female fetus. At ten weeks' gestation chorionic villus sampling demonstrated a female fetus, who was shown subsequently to be affected by means of a linkage method in which probes to HLA genes DQA and DRB were used as markers for the 21-hydroxylase genes. Increased 17-hydroxyprogesterone and androstenedione immunoactivity in amniotic fluid obtained at 14.5 weeks confirmed the fetus to be affected and demonstrated incomplete suppression of fetal adrenal androgen production. Dexamethasone was continued to term and maintained suppression of the fetal and maternal adrenal glands.The infant was born with normal female genitalia. Growth retardation was present but the relationship between this and the dexamethasone treatment remains uncertain. The mother had excessive weight gain during pregnancy.Dexamethasone treatment commenced in the first weeks of pregnancy can prevent or reduce virilisation of female fetuses with congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency.

Despite the absence of “conscious”, overt identification, some patients with face recognition impairments continue covertly to process information regarding face familiarity. The fact that by no means all patients show these covert effects has led to the suggestion that indirect recogntion tasks may help in identifying different types of face recognition impairment. The present report describes a number of experiments with the patient NR, who, after a closed head injury, has been severely impaired at recognizing familiar faces. Investigations mostly failed to show overt or covert face recognition, but NR performed at an above-chance level in selecting the familiar face on a task requiring a forced-choice between a familiar and an unfamiliar face. This discrepancy between a degree of rudimentary overt recognition and absence of covert effects on most indirect tests was addressed using a cross-domaim identity priming paradigm. This examined separately the possibility of preserved recognition for faces that NR consistently chose correctly in a forced-choice familiarity decision and those on which he performed at chance level. Priming effects were apparent only for the faces that were consistently chosen as “familiar” in forced-choice. We suggest that NR's stored representations of familiar faces are degraded, so that face recognition is possible only via a limited set of relatively preserved representations able to support a rudimentary form of overt recognition and to facilitate performance in matching and priming tasks.

Very little is known about the treatment of children with an obsessive-compulsive disorder (OCD). No controlled studies have been conducted into the effects of behaviour therapy or other kinds of psychotherapy. There have only been three studies into the effects of antidepressants. After providing some general information on OCD, this article discusses the possibilities, effects and some of the difficulties of treatment.

the Screening Tests. (MMSE 291, ACE 926). Significant differences were found betweenpatients andnormal controls in the following tests: a) FrontalAssessment Battery (p=0.19); b) Conceptualization Subscale (p=0.006); c) Differ Memory Reys List (p=0.03), Boston Naming Test (p=0.019), Semantic Verbal Fluency (p=0.021); d) Letters and Numbers (p=0.033); e) Wisconsin Card Sorting Test (p=0.032); f) Hotel task deviation of time (p=0.018); g) Met-hv total failures (p=0.001), Aim Interpretation Subscale (p=0.003), Fulfillment of tasks Subscale (p=0.001), Inefficiencies Subscale (p=0.000) and h) Test of Attentional Performance, Flexibility Subscale (p=0.045). Conclusions: This study supports previous reports showing that there is a pattern of cognitive abnormalities after focal cerebellar damage that especially includes impairments of executive functions (planning, setshifting, abstract reasoning, verbal fluency, working memory). Moreover, it suggests that the ecological executive battery used in this investigation might be much more sensitive for the detection of deficits in real life executive functions in these patients.

To the Editor: We read with great interest the recent article by Kumral et al1 on caudate vascular lesions and functional outcome. We agree with the authors that it is indeed important to take into account behavioral abnormalities after subcortical stroke. However, we would like to comment on the authors’ suggestion of the role of the caudate nucleus in the integration of verbal and visual memory, especially on the interpretation and the conclusion drawn from the neuropsychological test results. Verbal memory function was assessed by means of the Rey Auditory Verbal Learning Test (AVLT), originally developed by Rey.2 This widely used task consists of a list of 15 words that has to be remembered in 5 consecutive learning trials. After each presentation, the patient is prompted to recall as many words as he or she can remember from that list, thus providing information on immediate recall and verbal learning. To determine whether a patient is verbally amnesic, Kumral et al …

Nine cases are described of tetrasomy 18p resulting from the presence of an isochromosome 18p [i(18p)]. The initial diagnosis of i(18p) was by standard cytogenetic techniques and was confirmed by in situ hybridization with a biotinylated alphoid probe (L1.84) specific for the pericentric region of chromosome 18 and with a tritium-labeled chromosome 18 probe (B74) which hybridizes to the D18S3 locus situated at 18p11.3. The clinical features of the cases are summarized and shown to constitute a distinct and recognizable syndrome. Common features were low birth weight, a characteristic facies, neonatal hypotonia with subsequent limb spasticity, short stature, microcephaly, mental retardation, and seizure disorders. On the basis of size and cytogenetic banding a marker chromosome can be suspected to be an i(18p). In situ hybridization with the alphoid probe L1.84 provides confirmation of chromosome 18 origin. This more precise diagnosis will be an advantage in situations of pre- and postnatal diagnosis, since parents can be provided with a more confident prognosis for their child.

Fifty obsessive–compulsives were treated by behavioural therapy (self-exposure in vivo and response prevention) either with their partner directly involved in all aspects of treatment or without their partner. The two treatment formats were equally effective. Although a substantial number of obsessive–compulsives were found to have marital problems, behavioural treatment directed at the obsessive–compulsive disorder resulted in improvement irrespective of marital quality and partner involvement in the therapy. The effects of treatment led neither to a deterioration of the marriage nor to adjustment problems in the partner.

We report on a patient with humeroradioulnar synostosis and lambdoid synostosis. The case differs from three previously described cases in minor details, but the upper limb abnormalities are strikingly similar.

Condensation of (3 R )-3-levulinoyloxydecanoic acid ( 16 ) with methyl (3 R )-3-hydroxydecanoate ( 13 ) afforded, after selective delevulinoylation, methyl (3 R )-3-[(3 R )-3-hydroxydecanolyloxy]decanoate ( 18 ). Boron trifluoride etherate-promoted coupling of 3,4-di- O -benzyl-2- O -chloroacetyl-α- l -rhamnosyl fluoride ( 11 ) with 18 yielded exclusively an α-glycoside 19 , which, after removal of the chloroacetyl group, coupling with 11 , and removal of the protecting groups, afforded the title rhamnolipid 1 .

A direct assay has been developed for succinic semialdehyde dehydrogenase in sonicates of human lymphocytes and Epstein-Barr Virus transformed cultured lymphoblasts. Enzyme activity was quantified by incubating cell extracts with uniformly labeled [14C]succinic semialdehyde and monitoring the conversion to [14C]succinic acid. Radiolabeled products were separated by liquid partition chromatography on hydrated silicic acid. Kinetic properties and requirements of succinic semialdehyde dehydrogenase in lymphoblast sonicates were investigated in order to determine optimal conditions for the direct assay. Enzyme activity was stimulated by dithiothreitol, ammonium and potassium ions and 0.1% Triton X-100. The concentrations for half maximal activation by ammonium and potassium were 5.2 and 13.7 mM respectively. The mean activity of succinic semialdehyde dehydrogenase in assays in which equimolar NADP+ had been substituted for NAD+ was 19% of the activity of assays which contained NAD+. Substrate Michaelis constants were 21 and 30 microM for NAD+, and 26, 42 and 70 microM for succinic semialdehyde. The enzyme displayed a pH optimum between 8 and 9 and demonstrated a slight temperature activation between 37 degrees and 45 degrees C. A deficiency of succinic semialdehyde dehydrogenase activity was documented in cultured lymphoblasts derived from a patient with gamma-hydroxybutyric aciduria.

Six patients are described with a combination of early onset of neurological symptoms, gross cerebral changes and elevated concentrations of pyruvate and lactate in cerebrospinal fluid. Although at least five of the six patients appear to have a generalised defect in pyruvate metabolism, reflected in deficient pyruvate dehydrogenase activity in cultured fibroblasts, systemic acidosis was not a problem clinically and blood pyruvate and lactate concentrations were only slightly raised. The localisation of significant clinical and biochemical problems to the central nervous system, coupled with the difficulties in making the diagnosis if analysis of cerebrospinal fluid (CSF) is not performed, lead us to term this condition "cerebral" lactic acidosis.

A second child with a more severe deficiency of malonyl CoA decarboxylase is described. He is mildly mentally retarded and presented with vomiting, a seizure, hypoglycaemia and mild metabolic acidosis during a urinary tract infection. The urine contained increased, amounts of malonic, methylmalonic, succinic, adipic, glutaric and suberic acids. Mitochondrial malonyl CoA decarboxylase activity in cultured fibrobast extracts was 4% of the mean control value. A high fat, low carbohydrate diet led to symptomatic hypyglycaemia, a moderate metabolic acidosis and excretion in the urine of large amounts of the same organic acids and 3-hydroxybutyrate. Only relatively small quantities of malonic, methylmalonic and succinic acid were excreted in the urine when the boy was fed an isocaloric low fat, high carbohydrate diet. Acute fat and lysine loads led to increased excretion of malonic acid in the urine without affecting the excretion of the other organic acids. Experience with this patient, suggests that malonyl CoA decarboxylase serves an important function in the mitochondrion by preventing accumulation of malonyl CoA. The importance of the enzyme is best seen when fat is the main metabolic fuel. The mechanisms by which malonyl CoA produces its complex metabolic effects remain to be elucidated.

The determination of small, water soluble amines such as aziridine and 2-chloroethylamine, in drug substances at trace levels is described. After removal of the bulk of the drug substance by extraction or precipitation, derivatization with acid chlorides is performed. In a two-phase (water-organic solvent) system, this derivatization reaction is accomplished almost simultaneously with the extraction of the product to the organic layer. The organic layer is analyzed by gas chromatography using on-column injection and selective detection. Detection limits are approx. 0.2 mg/kg for aziridine and approx. 0.5 mg/kg for 2-chloroethylamine.

Persistent excretion of 3-methylglutaconic acid was found in a 6-month-old infant with multiple minor physical malformations and delayed development. During two episodes of intercurrent viral illness, the patient developed severe metabolic acidosis and excreted large amounts of lactate, 3-hydroxybutyrate and acetoacetate. The excretion of 3-methylglutaconic acid did not change during these episodes, nor did it increase following leucine loading. In vitro studies suggest that in this patient, as in the majority of other patients with 3-methylglutaconic aciduria, a primary defect in leucine metabolism is not responsible for the biochemical abnormality.

Kinetics of catecholamine biosynthesis and metabolism have been examined in patients with hereditary progressive dystonia with marked diurnal fluctuation of symptoms (HPD, Segawa's disease). Three patients and a healthy control received an oral load of deuterated tyrosine, and monodeuterium labelled catecholamines and their metabolites in urine and plasma were examined by gas chromatography-mass spectrometry. Patients excreted normal amounts of the primary metabolites of dopamine (dihydroxyphenylacetic acid, homovanillic acid) in urine, suggesting normal rates of dopamine production. However, the biological half-life of dopamine in the patients was reduced to about half that of controls. Noradrenaline biosynthesis and metabolism were normal. Taken together, these results are interpreted to show a reduced biological half-life of dopamine in the brains of these patients, possibly caused by a defect in dopamine storage. Impaired dopamine storage may be the basis of the diurnal fluctuation in symptoms.

Neocortical tissue prisms prepared from rat and human brain were frozen to -196 degrees C by a two-step freezing procedure and 10% dimethyl sulphoxide as cryoprotectant. Frozen and thawed rat neocortical prisms incorporated glucose into acetylcholine and carbon dioxide at 89% and 86% of control values, respectively, and noradrenaline uptake into frozen and thawed rat prisms was 94% of the control value. Frozen and thawed prisms from three human neocortical specimens showed a similar degree of protection from freeze-thaw injury.

Hot wires of various design, operated by the constant resistance method, were calibrated by means of a plane sound wave of 2500 Hz. This is achieved by locating a small open resonance tube axially in a homogeneous incompressible airflow. Its third harmonic is excitated by superimposing a coaxial, damped, progressive, plane wave on the main airstream. The hot wire to be calibrated is situated in an anti-node of the particle velocity. The amplitude at this station is known from the pressure gradient of the standing wave measured at two small holes in the wall by a probe microphone. This device in turn is calibrated in a specially developed “pistonphone”. Numerical results of the diverse designs are communicated; an absolute accuracy of ±2% is achieved.

A theoretical and experimental investigation is made of supersonic ejectors with mixing at constant cross-section. In the theoretical part formulae are derived treating the essential points of the behaviour of such an ejector. The theory is mainly based upon one-dimensional flow of a perfect gas; some extensions are included concerning the influence of friction and mixing profile.

Measuring a fluctuating pressure at a discrete point in an air flow requires a narrow probe connected by a transmission tube (of arbitrary length) to the membrane chamber of a microphone. A correct transmission of the pressure in the tube is achieved by a special construction of the chamber giving the tube the characteristic specific acoustic impedance at its terminal. The chamber is accordingly shunted to the ambient atmosphere by a narrow slit; the effect of the inertia of the slit is balanced by the capacity of the chamber, the resistance constitutes the required real impedance.

Es ist eine Methode für die Messung eines schwankenden Staudruckes entwickelt worden. Das Gerät besteht aus Staurohr, Verbindungsrohr, piezo-elektrischem Druckaufnehmer und elektrischem Filter. Die aerodynamischen, mechanischen und elektrischen Eigenschaften des Systems werden besprochen und eine Eichmethode beschrieben. Das ausgeführte Gerät besitzt eine nahezu geradlinige Eichkurve bis 800 Hz und eignet sich für die Turbulenzmessungen hinter verschiedenen Gittern. Die Ergebnisse stimmen befriedigend mit Hitzdrahtmessungen überein.

A search for high molecular residues in penicillin G was carried out using several recently described methods. By the membrane filtration method the protein content of a large number of batches of penicillin G, 6-APA (chemically prepared), and ampicillin was determined. Significantly lower protein values were found for these compounds than for microbiologically produced 6-APA and the ampicillin made from it. Purified macromolecular complexes of penicillin gave protein values in the membrane filter method. Our results indicate that the protein content of most commercially available benzylpenicillins is negligible.

The aim of the investigation was primarily the computation of the dynamical corrections on the static calibration curve. A brief account is given of the available analytical expressions for the heat transfer of a hot wire to the ambient airflow. The appropriate form is inserted in the small perturbation energy equation giving, with constant values of the characteristic parameters, a linear second order differential equation. A number of numerical examples was computed from the exact solution yielding the influence of frequency on the sensitivity and the temperature distribution along the wire. The analysis is supplemented by a short review of some complicating factors not included in the linear theory.