Courtesy Of Dr Research Articles

Idiopathic progressive chorea: misnomer or still reality? A case with neuropathological disconfirmation

Dear Sir,Most of the rarer causes of chorea have been clarified in thelast decades [1], so that the classic term of ‘‘idiopathicchorea’’ has been critically put into question.A 50-year-old Caucasian woman was referred formarked and progressive generalized chorea. The onset wasabout 1 year before and a depressive syndrome was alsopresent. Past medical and family histories were unre-markable. Slight dysarthria and adiadochokinesia werenoted. Ocular movements were normal. Deep tendonreflexes were diffusely enhanced and plantar response wasin extension bilaterally. Routine serology, ceruloplasmin,tumour markers, HIV serology, onconeural- and auto-antibodies were negative. The anti-streptolysin-O titre wasborderline and careful examination of blood smears failedto demonstrate acanthocytes. A magnetic resonance and a99mTc-ECD SPECT brain scans were not significant. Theneuropsychological assessment evidenced only minorimpairment in selective attention and slight dysexecutivenotes. Genetic testing for Huntigton’s disease (HD, 17/25triplets), DRPLA (150/150), SCA17 (36/37), SCA1 (21/30), SCA2 (23/23), SCA3 (20/22), SCA6 (11/12), SCA7(9/11), and FXTAS (23/23) were negative. Progranulin andPRNP mutations or C9orf72 expansions were absent. Anti-basal ganglia antibodies (ABGA) testing (courtesy ofDr. Giovannoni and Martino, UCL, UK) resulted in a weakpositive binding to pyruvate kinase M1 (60 kDa), while nobinding was shown for both gamma-neuron specific eno-lase, and aldolase C.Since neuroleptics were ineffective, a trial with high-dose IV steroids was attempted, with no immediateimprovement (HD Functional Capacities score: 2/13, stageIV; Folstein Chorea Scale score: 37/57). Three monthslater, only minor changes were noted (HDFCS: 3/13, stageIV; FCS: 27/57). The patient further deteriorated present-ing diffuse spasticity and dystonia. Due to worseningdysphagia the patient was referred for PEG positioning, butshe anyhow died of aspiration pneumonia about 4 yearssince the onset of chorea.The neuropathological study was carried out on forma-lin-fixed sections stained with hematoxylin-eosin, cresylviolet for Nissl substance, Heidenhain-Woelcke for myelin,thioflavine S for amyloid, and silver salts for neurofibrillarychanges (Bodian’s method). Immunohistochemistry wasperformed with antibodies to beta-amyloid (4G8), alpha-synuclein (4D6), ubiquitin (polyclonal), phosphorylated tau(AT8), prion protein (3F4), GFAP (polyclonal), CD3/43,leucocytes common antigen CD45, and MBP (polyclonal).Histopathological examination revealed mild neuronal lossin the cerebral cortex and basal ganglia. Reactive astrogl-iosis and microglia activation were marked in the thalamus,caudate, putamen and substantia nigra (SN) and morepronounced in the brainstem and cerebellum. Slight peri-vascular lymphocytic infiltration was present in the hemi-spheric and cerebellar white matter as well as in thestriatum, thalamus and brainstem. Extracellular deposits orintracellular inclusions were absent but esinophilic, ubiq-uitin-positive inclusions suggestive of Marinesco bodieswere found only in the SN. No clear retrospective corre-lation with imaging data was possible.

In Vivo Imaging of Neurovascular Remodeling After Stroke

Stroke is one of the leading causes of adult disability throughout the world and, even though neural mechanisms of loss of function have been extensively studied, many aspects of poststroke cerebral responses remain poorly understood. Of particular interest is the mounting evidence of the capacity of the adult brain to reorganize after injury, which is believed to contribute to limitation of the extent of neural dysfunction and to restoration of affected neural functions. Processes such as neuronal plasticity, glial proliferation, and neovascularization may be essential for preservation or recovery of function after stroke and may conceivably go hand-in-hand at nearby and remote sites of active tissue reorganization.1,2 Specifically, the acute initiation of neurovascular remodeling, stimulating the proliferation and growth of existing arteries/arterioles (ie, arteriogenesis) or new capillaries (ie, angiogenesis), may be critical to facilitate the survival and restructuring of neural tissue, which ultimately may contribute to functional recovery at later stages.3 A variety of vascular imaging strategies is available for in vivo detection, characterization, and quantification of these processes, which can significantly aid in elucidation of the role of neurovascular remodeling after stroke, as discussed in this review. Because most of the described imaging modalities are present in experimental and clinical settings, this raises significant opportunities for translational studies. Growth and remodeling of existing and nascent vascular networks in health and disease involve a number of critical steps that have been comprehensively described by Risau4 and Carmeliet.5 Arteriogenesis involves adaptive growth and proliferation of preexisting (collateral) arteries and arterioles in response to increase in intravascular shear forces. The increased shear stress leads to upregulation of cell adhesion molecules, followed by accumulation of monocytes and other leukocytes that release cytokines and growth factors around the proliferating and maturating arteries.6 Although arteriogenic growth of collateral …

Synaptically evoked Ca2+release from intracellular stores is not influenced by vesicular zinc in CA3 hippocampal pyramidal neurones

The co-release of neuromodulatory substances in combination with classic neurotransmitters such as glutamate and GABA from individual presynaptic nerve terminals has the capacity to dramatically influence synaptic efficacy and plasticity. At hippocampal mossy fibre synapses vesicular zinc is suggested to serve as a cotransmitter capable of regulating calcium release from internal stores in postsynaptic CA3 pyramidal cells. Here we investigated this possibility using combined intracellular ratiometric calcium imaging and patch-clamp recording techniques. In acute hippocampal slices a brief train of mossy fibre stimulation produced a large, delayed postsynaptic Ca(2+) wave that was spatially restricted to the proximal apical dendrites of CA3 pyramidal cells within stratum lucidum. This calcium increase was sensitive to intracellularly applied heparin indicating reliance upon release from internal stores and was triggered by activation of both group I metabotropic glutamate and NMDA receptors. Importantly, treatment of slices with the membrane-impermeant zinc chelator CaEDTA did not influence the synaptically evoked postsynaptic Ca(2+) waves. Moreover, mossy fibre stimulus evoked postsynaptic Ca(2+) signals were not significantly different between wild-type and zinc transporter 3 (ZnT3) knock-out animals. Considered together our data do not support a role for vesicular zinc in regulating mossy fibre evoked Ca(2+) release from CA3 pyramidal cell internal stores.

An ‘Ionospheric Weather’ Index

This note explains a method for deriving a daily ' ionospheric weather ' index for a given geographic location, and displays the behaviour of this index for the Boulder ionosphere during 8 months of 1968. ' Ionospheric weather ' means the dynamic state of the ionosphere at a particuIar time and place, as influenced by the number and intensity of ionization ' irregularities ' present. Such an index should be useful in attempts to associate short-term fluctuations in ionospheric electron density with other geophysical events, and ultimately, if such associations can be found, in forecasting the dynamic properties of ionospheric telecommunication circuits. The index is derived from continuous, steep-incidence, HF Doppler ionospheric soundings of the type described by Davies & Baker (1966). Ionospheric irregularities cause changes in the radio reflection height, which are recorded as fluctuations in the received frequency (Doppler shifts) of a stable 5 MHz radio wave reflected from heights of about 200 km in the F region. A great variety of irregularity ' signatures ' appear on Doppler-shift-vs-time records, many of which are attributable to the passage of atmospheric waves, whose properties can be measured with spaced sounders (Georges 1968; Davies & Jones 1971). At other times, the fluctuations are nearly random in appearance, defying most quantitative analyses. It was quickly learned, however, that the intensity of the fluctuations seemed to wax and wane on time scales of a few days, and also that intensity bore no obvious relation to other geophysical phenomena (except that high Doppler activity characteristically accompanies geomagnetic storms). Fig. 1 shows representative samples of ' quiet ' and ' disturbed ' Doppler records, as well as one containing wavelike frequency fluctuations. The Boulder data cited here were made available through the courtesy of Dr K. Davies of the NOAA Space Environment Laboratory. The unanswered question is: what causes the variations in ionospheric weather that are not associated with magnetic disturbances? In order to examine possible connections with other geophysical events (specifically, tropospheric weather) it was necessary to find a way to quantify the degree of ionospheric activity represented by a given Doppler record. Although it is often easy to subjectively classify a given record as ' quiet ' or ' disturbed ', many fall in between, and it seemed desirable to develop a more quantitative and objective indicator of' ionospheric activity. After several attempts that need not be discussed here, it was found that measuring the total length of the Doppler trace for a fixed time interval, though physically meaningless, provided a single number that agreed well with subjective feelings about the degree of activity present. To quantify one day's activity in a single number, the line length for the 8-hr interval centred on local noon was measured and divided by the length of the time

Mupirocin resistance among staphylococci: trends in the southern region of Ireland

Sir, Mupirocin is a topical antibiotic used particularly to eradicate methicillin-resistant Staphylococcus aureus (MRSA) carriage and to prevent infection. It is currently not mandatory in Ireland to screen patients for MRSA and decolonize them. Mupirocin-resistant strains are divided into two distinct groups: those with low-level mupirocin resistance (LMR); and those with high-level mupirocin resistance (HMR). LMR (MIC 8–256 mg/L) results from spontaneous point mutations in the chromosomally encoded ileS gene, which is stable and nontransferable. Strains with HMR (MIC.512 mg/L) possess mupA encoding a second staphylococcal ileS, which is found on an extrachromosomal plasmid and is transferable. There is evidence for the conjugative transfer of mupirocin resistance from Staphylococcus epidermidis to S. aureus in a clinical situation following mupirocin treatment. Our study assessed the prevalence and types of mupirocin resistance in a population of clinical staphylococcal isolates, including methicillinsusceptible S. aureus (MSSA), MRSA and coagulase-negative staphylococci (CoNS). A total of 300 anonymized, non-duplicate isolates of staphylococci were obtained from the Department of Microbiology at Cork University Hospital (CUH) between January 2006 and March 2007. The collection comprised the following: 100 MSSA isolates, of which 33 were from blood cultures and 67 were from wound sites; 100 MRSA isolates, of which 79 were from wound sites and 21 were from MRSA screening; and 100 CoNS, all from blood cultures. All blood culture isolates and MRSA screens were collected from CUH inpatients, and wound swab isolates were derived from both inpatients and nonhospital patients. Control strains were as follows: HMR MRSA and LMR MRSA (courtesy of Dr N. Shetty, UCLH–PHLS, London, UK); and S. aureus ATCC 25923. All isolates were screened for mupirocin resistance by disc diffusion (5 and 200 mg) using interpretative criteria recommended by Creagh and Lucey. Etest strips (AB Biodisk, Solna, Sweden) were used to determine mupirocin MICs for a subset of 84 isolates, including all HMR and LMR isolates (n1⁄436) and 48 random isolates selected from the susceptible population. Following susceptibility testing, API Staph (BioMerieux) was used for speciation of the mupirocin-resistant CoNS isolates. A crude DNA extraction was performed using a standard boiling method. PCR amplification of a 456 bp fragment of the mupA gene was performed according to the method of Anthony et al. A PCR amplicon from an HMR isolate from each group (MSSA, MRSA and CoNS) was purified using a QIAquick-spin PCR purification kit (Qiagen Ltd, West Sussex, UK) and sequenced commercially at MWG-Biotech (Ebersberg, Germany). Sequencing data were compared with mupA gene sequences in the current GenBank database using BLAST analysis (data not shown). SCCmec typing was performed on a subset of MRSA isolates (n1⁄425) according to the method of Oliveira and de Lencastre. Figure 1 shows the distribution of mupirocin susceptibility among the study collection. The MICs for susceptible, LMR and HMR isolates tested were ,8 mg/L, 8–32 mg/L and .1024 mg/L, respectively. The presence of the mupA gene was confirmed by PCR for the 26 isolates designated HMR on the basis of susceptibility testing and was not detected among the remaining population of isolates. Following API Staph on all HMR and LMR CoNS (n1⁄432), 27 isolates were determined to be S. epidermidis (17 HMR and 10 LMR). Two HMR CoNS were identified as Staphylococcus xylosus and the remaining three HMR isolates failed to identify to species level using this system. Overall, the collection of staphylococci demonstrated 8.7% HMR and 3.3% LMR. S. aureus isolates showed 2% HMR, in contrast to CoNS at 22% HMR. (The S. aureus HMR strains were isolated from inpatients only.) In this study, LMR was found only in the CoNS group and represented 10% of this group. When compared with the study by Creagh and Lucey, conducted on 502 isolates collected during 2003, the absence of LMR among MRSA in the present study contrasts dramatically

Percutaneous Treatment of Mitral Regurgitation

Percutaneous mitral valve therapy became a reality more than 25 years ago with the first description of balloon valvuloplasty for rheumatic mitral stenosis.1 More recently, percutaneous closure of paravalvular leaks after surgical valve implantation has been shown to have a potential, but limited, role.2–4 However, valvular mitral regurgitation (MR) remains largely the purview of surgery. Recently, the potential for less invasively replicating these successful surgical procedures without the need for thoracotomy or cardiopulmonary bypass has generated considerable interest. For the most part, these new approaches are modeled after established surgical strategies. Percutaneous approaches to mitral repair can be broadly divided into procedures that address the various components of the mitral valve. For purposes of discussion, the mitral valve can be considered to have several component parts: leaflets, subvalvular apparatus (chordate tendinae and papillary muscles), annulus, left atrium, and left ventricle.5 All are integral to the normal function of the mitral valve and each is a potential avenue for repair. Although many such avenues may not lead to an effective surgical option, it may be unwise to dismiss the possibility that others will achieve some measure of success. We briefly review the current percutaneous therapies being developed and evaluated for the management of MR. The current status of various percutaneous therapies is presented in Table 1. View this table: Table 1. Current Status of Percutaneous Mitral Valve Repair Procedures ### Leaflet Repair Complex leaflet repair is currently beyond the reach of a percutaneous approach. However, the relatively simple but, in selected patients, effective “double-orifice” surgical repair initially described by Alfieri and coworkers6 can be reproduced. In the surgical procedure, the free edges of the mitral leaflets are sutured together in the mid portion creating 2 separated orifices. Generally, surgical leaflet repair is combined with implantation of an annuloplasty ring. The surgical literature …

Autoregulatory Role of Endothelium-derived Nitric Oxide (NO) on Lipopolysaccharide-induced Vascular Inducible NO Synthase Expression and Function

Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is responsible for sepsis-induced hypotension and plays a major contributory role in the ensuing multiorgan failure. The present study aimed to elucidate the role of endothelial NO in lipopolysaccharide (LPS)-induced iNOS expression, in isolated rat aortic rings. Exposure to LPS (1 mug/ml, 5 h) resulted in a reversal of phenylephrine precontracted tone in aortic rings (70.7 +/- 3.2%). This relaxation was associated with iNOS expression and NF-kappaB activation. Positive immunoreactivity for iNOS protein was localized in medial and adventitial layers of LPS-treated aortic rings. Removal of the endothelium rendered aortic rings resistant to LPS-induced relaxation (8.9 +/- 4.5%). Western blotting of these rings demonstrated an absence of iNOS expression. However, treatment of endothelium-denuded rings with the NO donor, diethylamine-NONOate (0.1 mum), restored LPS-induced relaxation (61.6 +/- 6.6%) and iNOS expression to levels comparable with arteries with intact endothelium. Blockade of endothelial NOS (eNOS) activation using geldanamycin and radicicol, inhibitors of heat shock protein 90, in endothelium-intact arteries suppressed both LPS-induced relaxation and LPS-induced iNOS expression (9.0 +/- 8.0% and 2.0 +/- 6.2%, respectively). Moreover, LPS treatment (12.5 mg/kg, intravenous, 15 h) of wild-type mice resulted in profound elevation of plasma [NO(x)] measurements that were reduced by approximately 50% in eNOS knock-out animals. Furthermore, LPS-induced changes in vascular reactivity and iNOS expression evident in wild-type tissues were profoundly suppressed in tissues taken from eNOS knockout animals. Together, these data suggest that eNOS-derived NO, in part via activation of NF-kappaB, regulates iNOS-induction by LPS. This study provides the first demonstration of a proinflammatory role of vascular eNOS in sepsis.

The hydrogenase-like Nar1p is essential for maturation of cytosolic and nuclear iron-sulphur proteins.

The genome of the yeast Saccharomyces cerevisiae encodes the essential protein Nar1p that is conserved in virtually all eukaryotes and exhibits striking sequence similarity to bacterial iron-only hydrogenases. A human homologue of Nar1p was shown previously to bind prenylated prelamin A in the nucleus. However, yeast neither exhibits hydrogenase activity nor contains nuclear lamins. Here, we demonstrate that Nar1p is predominantly located in the cytosol and contains two adjacent iron-sulphur (Fe/S) clusters. Assembly of its Fe/S clusters crucially depends on components of the mitochondrial Fe/S cluster biosynthesis apparatus such as the cysteine desulphurase Nfs1p, the ferredoxin Yah1p and the ABC transporter Atm1p. Using functional studies in vivo, we show that Nar1p is required for maturation of cytosolic and nuclear, but not of mitochondrial, Fe/S proteins. Nar1p-depleted cells do not accumulate iron in mitochondria, distinguishing these cells from mutants in components of the mitochondrial Fe/S cluster biosynthesis apparatus. In conclusion, Nar1p represents a crucial, novel component of the emerging cytosolic Fe/S protein assembly machinery that catalyses an essential and ancient process in eukaryotes.

Hepatitis C Virus Antibody in Acute and Chronic Liver Diseases in India

Non-A, non-B hepatitis (NANBH) is the major cause of acute and chronic active hepatitis in India (1). This infection leads to severe liver damage when associated with hepatitis B virus (HBV) infection (2). The etiological agents responsible for NANBH are 2 recently characterised major groups of viruses, i.e. hepatitis-E virus, HEV (3) and hepatitis-C virus, HCV (4). HEV is associated with waterborne hepatitis, HCV is the causative agent of bloodborne hepatitis. It is already established that HEV is the foremost cause of waterborne epidemics of viral hepatitis in different parts of the world. However, the relative roles of HEV and HCV in the causation of acute sporadic hepatitis is not known. The present study was designed to evaluate the prevalence of anti-HCV in sporadic acute and chronic viral hepatitis patients in India. Using Ortho-ELISA kits for anti-HCV, the antibody was tested by the courtesy of Dr T. Uchida (Nihon University, School of Medicine, Tokyo, Japan) in serum samples collected from patients of fulminant hepatitis (n=28), subacute hepatic failure (a= 12) and chronic active hepatitis (n=7). All these patients were positive for HBsAg but negative for IgM anti-HBc and IgM anti-HAV, thus forming a group of HBV carriers without active HBV or hepatitis A virus (HAV) infections. The results of this study demonstrated that antiHCV was present in 45% of fulminant hepatitis, 58% of subacute hepatitis and 43% of chronic active hepatitis patients. These data indicate that HCV infection is quite frequent in India. However, at present, it appears difficult to explain such a high prevalence of anti-HCV in fulminant and subacute hepatitis patients, which is in contrast to the earlier reports that anti-HCV is present only in 15-25 Yo (5) of cases with acute infection. Presumably presence of HBsAg helps in aggravating the situation by enhancing host immune response vs. HCV leading to high anti-HCV positivity in acute infections. These antibodies may be involved in the pathogenesis of liver causing a massive liver damage. This is also supported by our earlier findings of high morbidity and mortality in the patients with superimposed NANB infection in HBV carriers (2).

Ultrastructure of the silenced synapse

The theoretical and practical importance of understanding the normal and abnormal function of the synapse has generated an intensity of research over the last two decades that has probably exceeded that in any other field of neuroscience. One of the many experimental approaches used to analyse the structure-function relationship in the synapse has been to block synaptic transmission and hence to see whether normal morphology is dependent upon normal function. For obvious technical reasons such studies have generally used synapses, between neurons or between neurons and muscle fibres, cultured in vitro. Cerebral cortex of late foetal or neonatal mice in vitro (see Ref. 1). Fig. 1. Explant in normal culture medium. Synapse shows two groups of vesicles presynaptieally and a typical synaptic cleft (arrows) and pre- and post-synaptic membranous thickenings (arrowheads). Figs 2 and 3. Explants in magnesium-rieh culture. In Fig. 2 the axon terminal is filled with synaptic vesicles. In Fig. 3 the synuptic cleft (arrows) and pre- and post-synaptic thickenings (arrowheads) have a normal appearance despite the magnesium-enriched medium, mt, mitochondria; ser, smooth endoplasmic reticulum; m, microtubules; n f,, neurofilaments. (Reproduced by courtesy of Dr M. Bird and Cell and Tissue Research.) 209 Early evidence that normal synaptic morphology was probably maintained even in synapses blocked for several weeks (by xylocaine or high external concentra- tions of magnesium) came from Crain and his colleagues 2. Within minutes of the removal of the blocking agents the normal complex electrophysiological responses could be elicited from the synapses. Recent evidence 1 indicates that normal morphol- ogy is generally retained and further that maturation of synapses can take place even when they are 'silenced' for prolonged periods. The formation of a mature pattern of pre- and post-synaptic thickenings, synap- tic cleft and cleft material is not affected by the absence of synaptic transmission. The one major structural change evident in the majority of 'silenced' synapses is the accumulation of large numbers of synaptic vesicles ~ indicating that there is some con- tinued synthesis and packaging of transmit- ter substances even in the absence of synaptic activity. It is perhaps surprising that vesicle formation does not appear to be directly linked to a feedback mechanism associated with vesicle release. The mag- nesium-enriched (8 mM) culture media is considered to block synapses by competing with calcium for active sites in the vesicle release mechanism 3. Nevertheless, vesicle formation continues in most magnesium- blocked synapses. The effectiveness of magnesium as a blocking agent can be demonstrated by its addition to fixatives for the preparation of normal CNS tissue for electron micro- scopy. The fixative glutaraldehyde appar- ently depolarizes nerve endings and pro- duces a considerable discharge of synaptic vesicles. However, the addition to the fixa- tive of magnesium in high concentration is sufficient to preserve a large 'excess' of ves- icles in presynaptic terminals 4.

Further studies on the nuclear chromatin of morphologically abnormal bull spermatozoa.

are commonly found in ejaculates from bulls with certain types of reduced fertility. Intranuclear spaces and a granular appearance of the nuclear chromatin were the major abnormalities observed in a high percentage of spermatozoa from two infertile bulls (McCosker, 1969). The organization of the DNA and nuclear proteins forming the deoxyribonucleoprotein complex (DNP) in the chromatin of deformed sperm heads has received little attention. Previous studies have demonstrated that most morphologically abnormal sperm heads contain the same amounts of DNA as their normally shaped counterparts (Gledhill, 1966a). Defects in the binding of nuclear protein to DNA, which probably occur during the process of chromatin aggregation in spermateliosis, have only recently been incriminated in the formation of certain misshapen sperm heads (Gledhill, Dar\l=z%o\ynkiewicz & Ringertz, 1971). Their possible r\l=o^\lein an instance of infertility was noted earlier (Gledhill, Gledhill, Rigler & Ringertz, 1966a). The present communication reports a study which had as its objective to determine if the DNA of abnormally shaped spermatozoa has a sensitivity to thermal denaturation that differs from that of normally shaped spermatozoa. The method used allows the analysis of molecular arrangements of DNA within intact, definable sperm heads. Such information has physiological importance as it relates to current work on the maturation ofnuclear chromatin and could show mechanisms which might be involved in the differentiation of abnormal sperm heads. Nine sexually mature and normally fertile dairy and beef bulls of varying ages (H to 15 years) and breeds were used. Spermatozoa from the testis and from the caput epididymidis were obtained in a manner previously described (Gledhill, 1966b). Spermatozoa were also obtained from the left vas deferens of two of the bulls (courtesy of Dr R. P. Amann, The Pennsylvania State Univers¬ ity) at 1 and 3 days after cannulation by a modification of the method of Amann, Hokanson & Almquist, (1963) and Sexton, Amann & Flipse (1971). Ejaculated spermatozoa were collected with the aid of an artificial vagina. The criteria used for differentiating morphologically abnormal from normal

Alkaloids of an Ipomoea seed known as Kaladana in Pakistan.

Ipomoea muricata Jacq. (Calonyction muricatum G. Don) has now been confirmed as the biological origin of the Ipomoea seed mentioned in a previous communication1. Seeds of Indian origin (obtained by courtesy of Dr O. Fervidi, Simes Servizi Scientifici, Milan), identical to those from Pakistan, showed on germination in Beirut the typical shape and size of the cotyledonary and first leaves of Ipomoea muricata Jacq. described by Kassner2. The identity was further confirmed by the characteristically tubercled stem3 and the aristate sepals4. Kaladana seeds, obtained from Pakistan (Gohar and Co., Karachi) in 1965 and 1967, differed from the original seeds (and those from India) in being hairy and greyish-black but otherwise identical to the original seeds in size and shape. All the seeds, however, had identical alkaloid chromatograms. A few of the 1967 seeds were grown in Lafayette, in 1968 (by courtesy of Dr J. E. Robbers, Purdue University, Lafayette). Seeds obtained from these plants and grown in Beirut produced plants identical to those obtained from the Indian seeds. Strangely enough, the seeds obtained from Lafayette were devoid of alkaloids. In this connexion it is interesting to note that Der Marderossian5 reports no indole alkaloids from “I. Muricata”. Besides lysergol and chanoclavine-I, reported1 as present in Kaladana seed, other alkaloids were also found but in much smaller amounts6.

Brain evolution and Archaeopteryx.

THE brain of Archaeopteryx lithographica, the earliest fossil bird, is known from a natural endocranial cast exposed in the famous specimen on display at the British Museum (Natural History). Edinger1 and de Beer2 have agreed that its brain was “similar in type and structure to that of reptiles and different from that of all other known birds” (ref. 2, page 13). Through the courtesy of Dr H. W. Ball, keeper of palaeontology at the museum, I have been able to examine a copy of the endocast prepared by de Beer. I agree that the brain differed from that of known birds, but it seems to me clearly avian in external form and intermediate between bird and reptile brains with respect to size. The new interpretation of Archaeopteryx results from the discovery of the true midline suture of the skull a few millimetres away from the line that has until now been thought to be the midline.

The infection of laboratory hosts with cercariae of Schistosoma mansoni and the recovery of the adult worms.

At present many laboratories throughout the world are studying the chemotherapy and immunology of Schistosoma mansoni in laboratory hosts. Many workers judge the success or failure of their attempts to cure or immunize these hosts from the ratio of the number of living adult worms recovered to the number of infecting cercariae. This ratio is affected, however, not only by the efficacy of any treatment, but also by the methods used to infect the animals and to recover the worms. If these methods result in widely varying worm recoveries amongst the animals in any experimental group, then small but significant effects of treatment might well be missed. Alternatively, such large experimental groups must be used that the work becomes tedious to perform and depends upon the availability of a great deal of technical assistance. This paper describes techniques which are rapid and do not require great skill in their performance. More important, in our hands they have given very consistent results. In this respect, particularly, we believe that these techniques have advantages over others which are currently practised.The techniques described here are those which were used in other investigations reported in this journal (Smithers & Terry, 1965a, b).The strain of S. mansoni used throughout this work was isolated in Puerto Rico and was obtained through the courtesy of Dr W. B. DeWitt of the National Institutes of Health. The parasite is maintained in an albino strain of Australorbis glabratus (Newton, 1955). Snails are exposed individually to ten miracidia overnight at 27 °C.

Linkage tests involving the P blood group locus and further data on the ABO: nail-patella linkage.

SummaryNo convincing evidence of linkage was found when an attempt was made to confirm a suspicion that the P blood group locus was linked both to the nail‐patella locus and to the ABO locus. In the course of this work, the ABO:nail‐patella linkage has been found to be consistent in six additional families and the revised estimate of the recombination fraction is 0–096 ± 0–024.We wish to thank Prof. L. S. Penrose for the help and interest he has shown in all aspects of this investigation and Dr C. A. B. Smith for guidance in the analyses.The study of the Danish families was given every encouragement by Prof. T. Kemp and the linguistic shortcomings of two of us were kindly circumvented by Miss Lene Ramvad.The analysis of the linkage data concerning ABO and P, on the computer made available by the courtesy of Dr F. Yates at Rothamsted Experimental Station, is mainly the work of Mr H. R. Simpson, to whom we are very grateful. We are much indebted to Dr R. R. Race for permission to incorporate in these data material collected by the M.R.C. Blood Group Research Unit.

The influence of low and high planes of nutrition on the composition and synthesis of fat in the pig

THE work described in this communication deals with the determination of the component acids in the depot fats of pigs which had received controlled diets at different levels of nutrition. The primary object was to ascertain how far the quantitative proportions of the various component acids varied in relation to the feeding level of the animal. It was also found possible to make a rough quantitative comparison of the amounts of each fatty acid (a) ingested by the animal, (b) deposited in the animal in the form of fat, and therefrom to deduce the amount and nature of fat synthesized in the animal, and also to compare the rates of deposition of fat in animals which had been given different rations. An investigation has recently been in progress at the Animal Nutrition Institute of the School of Agriculture, Cambridge, designed to determine the effect of rate of growth on the proportions of the different parts and tissues in the pig. The physiological and anatomical results of this investigation are in course ofpublication by Dr C. P. McMeekan. By the courtesy ofDr J. Hammond, specimens of the back and perinephric fats, in sufficient amounts for detailed component acid analyses to be made, were placed at our disposal, together with details of the diets received by the pigs and of the weights of their fatty tissues at the time of slaughter. We are informed by Dr Hammond that the plan of feeding was as follows. Thirty pigs of unusually homogeneous (inbred) stock were fed on the same diet in different amounts. Up to the age of 16 weeks the pigs were in two groups:

On the ascarids parasitic in seals, with special reference to the genus Contracaecum

Difficulties encountered in the determination of species of Contracaecum from seals led the writer to undertake a comparative morpholgical study of a considerable amount of material. This included the Ascarids from seals collected by the Scottish National Antarctic Expedition (Scotia) in 1902–4, and deposited in the Royal Scottish Museum, Edinburgh, which were obtained on loan through the courtesy of Dr A. C. Stephen. In the present paper some results of this investigation are presented, and short notes are added on other species of Ascaridae recorded from Pinnipedia.

A Re-examination of the Therfield Heath Long Barrow, Royston, Hertfordshire

Therfield heath, the expanse of chalk downland on the west side of Royston, has long enjoyed a local fame for the number of barrows and other antiquities which diversify its surface. On the north side it is bounded by the Icknield Way and so is well placed on the corridor between Wessex and East Anglia.By far the most important monument on the Heath is a small long barrow notable as the only example known in East Anglia, its nearest neighbours being the destroyed Dunstable barrow 25 miles to the west, and, further still, the Churn barrow west of the Thames near the Goring Gap.The outward form of the barrow is well-preserved (fig. 1, plan 1), exhibiting the typical club-shaped plan, the broader and higher end to the east. It is 110 feet long, 56 feet wide and 6 feet high at the east end, and 25 feet wide and 2 feet wide at the west. The Ordnance Survey references are Herts 6 inch 4 NE and 25 inch 4, 8. The latitude is 52°2′35″ and the longitude 0° 2′ 40″ w. The height above sea level is 385 feet.It is unfortunate that the late E. B. Nunn of Royston, who opened most of the barrows on the Heath, completely gutted the interior of this long barrow. By the courtesy of Dr W. M. Palmer, M.A., M.D., F.S.A. I am able to publish the following extract from Nunn's manuscript describing his operations here eighty years ago. Fig. 2 is a reproduction of the sketch which illustrates his account.

On a Chalcidoid Parasite bred from a Flea Larva

For the opportunity to examine the material on which the following descriptions are based I am indebted to the courtesy of Dr P. A. Buxton and Miss E. Sikes of the London School of Tropical Medicine, where the life-history of certain fleas is being studied. A detailed examination of the parasite showed it to be referable to the Pirenine tribe of the Miscogasteridae—a family of Chalcidoid wasps. The genus and species appeared to be new. The fact, however, that the parasite had been bred from a species of flea known to have been recently introduced into Britain suggested the advisability of comparison with American representatives of the Pirenine group. This has now been done by my friend Mr A. B. Gahan of the Bureau of Entomology, Washington, D.C., to whom my hearty thanks are due. As the result we are agreed that a new genus is required. Bairamlia n.g. has obvious affinities with Pirene Hal., but differs in antennal, neurational and propodeal characters. Ecrizotes Forst. (fide A. B. Gahan) may also be a nearly related genus. genus. As regards the species, I am satisfied that it is very different from anything described by Walker of which material is still extant in the British Museum. Mr Gahan, however, tells me that Pirene marylandensis Gir. (Canad. Ent. 48, p. 116, 1916) is a congeneric though distinct species.

Stibarobdella superba n.g. et sp. A New Ichthyobdellid Leech

Owing to the courtesy of Dr G. M. Vevers I have had the opportunity of examining a marine Ichthyobdellid leech, taken by Dr F. A. Phillipps from the cloaca of a shark, 7 feet long, caught between the islands of Aore and Santu, New Hebrides. The leech resembles Pontobdella superficially in being covered by warty tubercles. It possesses, however, certain peculiarities described below which justify its recognition not only as a new species but also as a representative of a new genus.