bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of bacteriocins from Lactococcus lactis subsp. lactis CECT 539 and Pediococcus acidilactici NRRL B‐5627 using mussel‐processing wastes
Authors: Guerra Nelson Pérez , Castro Lorenzo Pastrana
Published: November 2003

The growth and bacteriocin production by Lactococcus lactis subsp. lactis CECT 539 and Pediococcus acidilactici NRRL B‐5627 were investigated on mussel‐processing wastes. Both bacteriocin productions were satisfactorily modelled using a modified form of the Luedeking and Piret expression, which includes a term for the influence of the pH reduction rate. Experimental data from cultures buffered at different initial concentrations (0, 0.03, 0.10 and 0.25 M) of both bacteria were used to fit and verify the model. The influence of total sugars, nitrogen, phosphorus and buffer concentration on nisin and pediocin production was also studied using response‐surface methodology and empirical modelling. Enhanced nisin production (33 BU/ml) was achieved in media buffered with 0.10 M potassium hydrogen phthalate/NaOH. However, the highest levels of pediocin (368 BU/ml) were obtained in the non‐buffered media.
Purification and characterization of lysozyme‐pregnanediol glucuronide conjugates: the effect of the hapten and coupling reagent on the substitution level, sites of acylation and the consequences for the development of future immunoassays
Authors: Smales C. Mark , Blackwell Leonard F.
Published: November 2003

The preparation of conjugates destined for use in homogeneous enzyme immunoassays requires careful control to maximize the yield of conjugate, limit the level of substitution and obtain highly inhibitable conjugates. Furthermore, previous studies have shown that the acylation position and orientation of haptens in enzyme conjugates is important in determining the recognition and strength of binding of the hapten by anti‐hapten antibodies. In this study we have prepared and purified pregnanediol glucuronide conjugates of hen egg white lysozyme by the active ester and mixed anhydride methods and compared the resulting conjugates with those obtained when conjugating with oestrone glucuronide. Conjugation of lysozyme with pregnanediol glucuronide by the mixed anhydride procedure resulted in two major derivatives monoacylated at lysine residues 33 and 97, while acylation by the active ester procedure resulted in six major derivatives acylated at one or more of lysine residues 33, 97 and 116. Comparison of these conjugates with oestrone glucuronide conjugates suggested that when using the more reactive active ester method the protein environment of the amino groups and the acylating agent directed the site(s) of acylation and level of substitution. However, in the case of the less reactive mixed anhydride coupling procedure the chemical nature of the hapten also influenced the final conjugation product makeup. These findings have implications for the design of new, highly inhibitable enzyme conjugate immunoassay systems.
Preformulation study of the vaccine candidate TAB9 against HIV‐1
Authors: Raya Néstor Expósito , Díaz Alina García , López Yamilka Carrazana , Vazquez Diógenes Quintana , Díaz Dagmara Pichardo , Puente Nieves Martínez de la , Cano Carlos Duarte
Published: November 2003

A preformulation study was performed for the evaluation of a vaccine candidate against HIV‐1. Aluminium hydroxide was used in the preformulation. However, this adjuvant is not a good adsorbent for basic proteins since it is positively charged at a physiological pH. In the present study, we determined the adsorption of TAB9 (basic protein, pI: 11.3) by treating Alhydrogel with different ions. The immunogenicity of the vaccine candidate against HIV was also evaluated using three batches, 9801‐A, 9802‐A and 9803‐A, and a placebo P‐001. The evaluation was performed twice (0 and 9 months). Each batch was tested using groups of 10 mice that had a single inoculation. The results showed that the protein was totally adsorbed to the aluminium gel. Seroconvertion was attained in all analysed batches, indicating the potentiality of TAB9 as a vaccine candidate.
Stereotactic co‐registration of magnetic resonance imaging and histopathology in post‐mortem multiple sclerosis brain
Authors: Schmierer K. , Scaravilli F. , Barker G. J. , Gordon R. , MacManus D. G. , Miller D. H.
Published: November 2003

A number of groups have examined the pathological substrate of signal changes on magnetic resonance imaging (MRI) in post‐mortem (PM) brain of patients with multiple sclerosis (MS). Such studies will benefit from using a standardized method to reliably co‐register regions of interest on MRI and tissue specimens. We investigated the usefulness of a stereotactic navigation system for this purpose. We also addressed the sensitivity of different standard MRI sequences with regard to lesion conspicuity in PM MS brain. Post‐mortem brains of eight patients with MS were studied. Formalin‐fixed coronal slices were placed in the head frame of a stereotactic system. Proton density‐, T2‐weighted and fast fluid‐attenuated inversion recovery (FLAIR) scans were obtained and visually matched with scans that had been previously obtained on the same, but fresh, specimens. Guided by the stereotactic target points, the dissection of the fixed specimens was performed. After processing the blocks for embedding in paraffin, sections were stained with haematoxylin–eosin and Luxol fast blue. T2‐weighted MRI of fixed brain revealed 24 areas suspected to be MS lesions, all of which were confirmed histologically. Three of these lesions were not visible on macroscopic inspection. There were 14 additional hyperintensities on T2‐weighted or FLAIR MRI of the fresh specimens, five of which did not correlate to MS lesions histologically. Stereotactic navigation is a useful approach to co‐register MRI and histopathology in PM brain of MS patients and may improve the precision of MRI‐guided sampling of tissue specimens. Standard T2‐weighted MRI appeared to be the single most useful approach for lesion detection in fresh and fixed specimens.
CDKN2A, CDKN2B and p14 ARF are frequently and differentially methylated in ependymal tumours
Authors: Rousseau E. , Ruchoux M.‐M. , Scaravilli F. , Chapon F. , Vinchon M. , De Smet C. , Godfraind C. , Vikkula M.
Published: November 2003

Ependymal tumours are histologically and clinically varied lesions. Numerical abnormalities of chromosome 9 are frequently associated with these tumours. Nevertheless, the three important tumour suppressor genes located in this chromosome, CDKN2A, CDKN2B and p14 ARF, have not been reported to be commonly altered in them. We studied promoter methylation of these genes, an important mechanism associated with gene silencing in a series of 152 ependymal tumours of WHO grades I to III. Methylation status of the CDKN2A, CDKN2B and p14 ARF promoters was assessed by methylation‐specific polymerase chain reaction and the genetic results were correlated to clinicopathological features. We observed promoter methylation for CDKN2A in 21% (26/123) of tumours, for CDKN2B in 32% (23/71) and p14 ARF in 21% (23/108). For all three genes, posterior fossa ependymomas were less frequently methylated in paediatric patients than in adults. For CDKN2B, extracranial tumours were more frequently methylated than intracranial ones. For CDKN2B and p14 ARF, methylation was more frequent in low‐grade tumours; the reverse was observed for CDKN2A. CDKN2A, CDKN2B and p14 ARF promoters were methylated in 21–32% of the tumours. Frequencies of methylation varied  according  to clinicopathological features. This suggests a role for these genes in ependymoma tumorigenesis.
Lymphatic cerebrospinal fluid absorption pathways in neonatal sheep revealed by subarachnoid injection of Microfil
Authors: Zakharov A. , Papaiconomou C. , Djenic J. , Midha R. , Johnston M.
Published: November 2003

There is mounting evidence that a significant portion of cerebrospinal fluid drainage is associated with transport along cranial and spinal nerves with absorption taking place into lymphatic vessels external to the central nervous system. To characterize these pathways further, yellow Microfil® was infused into the cisterna magna of 2–7‐day‐old lambs post mortem to perfuse either the cranial or spinal subarachnoid compartments. In some animals, blue Microfil was perfused into the carotid arteries simultaneously. Microfil was observed in lymphatic networks in the nasal mucosa, covering the hard and soft palate, conchae, nasal septum, the ethmoid labyrinth and the lateral walls of the nasal cavity. Many of these lymphatics drained into vessels located on the lateroposterior wall of the nasopharynx and from this location drained to the retropharyngeal lymph nodes. Additionally, lymphatics containing Microfil penetrated the lateral wall of the nasal cavity and joined with superficial lymphatic ducts travelling towards the submandibular and preauricular lymph nodes. In two cases, lymphatic vessels were observed anastomosing with deep veins in the retropharyngeal area. Microfil was also distributed within the nerve trunks of cranial and spinal nerves. The contrast agent was located in longitudinal channels within the endoneurial space and lymphatics containing Microfil were observed emerging from the mesoneurium. In summary, Microfil distribution patterns in neonatal lambs illustrated the important role that cranial and spinal nerves play in linking the subarachnoid compartment with extracranial lymphatics.
Protein aggregation in motor neurone disorders
Authors: Wood J. D. , Beaujeux T. P. , Shaw P. J.
Published: November 2003

Toxicity associated with abnormal protein folding and protein aggregation are major hypotheses for neurodegeneration. This article comparatively reviews the experimental and human tissue‐based evidence for the involvement of such mechanisms in neuronal death associated with the motor system disorders of X‐linked spinobulbar muscular atrophy (SBMA; Kennedy's disease) and amyotrophic lateral sclerosis (ALS), especially disease related to mutations in the superoxide dismutase (SOD1) gene.

Evidence from transgenic mouse, Drosophila and cell culture models of SBMA, in common with other trinucleotide repeat expansion disorders, show protein aggregation of the mutated androgen receptor, and intraneuronal accumulation of aggregated protein, to be obligate mechanisms. Strong experimental data link these phenomena with downstream biochemical events involving gene transcription pathways (CREB‐binding protein) and interactions with protein chaperone systems. Manipulations of these pathways are already established in experimental systems of trinucleotide repeat disorders as potential beneficial targets for therapeutic activity.

In contrast, the evidence for the role of protein aggregation in models of SOD1‐linked familial ALS is less clear‐cut. Several classes of intraneuronal inclusion body have been described, some of which are invariably present. However, the lack of understanding of the biochemical basis of the most frequent inclusion in sporadic ALS, the ubiquitinated inclusion, has hampered research. The toxicity associated with expression of mutant SOD1 has been intensively studied however. Abnormal protein aggregation and folding is the only one of the four major hypotheses for the mechanism of neuronal degeneration in this disorder currently under investigation (the others comprise oxidative stress, axonal transport and cytoskeletal dysfunctions, and glutamatergic excitotoxicity). Whilst hyaline inclusions, which are strongly immunoreactive to SOD1, are linked to degeneration in SOD1 mutant mouse models, the evidence from human tissue is less consistent and convincing. A role for mutant SOD1 aggregation in the mitochondrial dysfunction associated with ALS, and in potentially toxic interactions with heat shock proteins, both leading to apoptosis, are supported by some experimental data. Direct in vitro data on mutant SOD1 show evidence for spontaneous oligomerization, but the role of such oligomers remains to be elucidated, and therapeutic strategies are less well developed for this familial variant of ALS.
Enhancing CTL responses to melanoma cell vaccines in vivo: synergistic increases obtained using IFNγ primed and IFNβ treated B7‐1+ B16‐F10 melanoma cells
Authors: Dezfouli Shala , Hatzinisiriou Irene , Ralph Stephen J
Published: November 2003

Sequentially treating human melanoma cell lines by priming with interferon‐gamma before adding interferon‐beta was previously found to be the most efficient protocol for producing concurrently increased expression of the three surface antigens B7‐1, intercellular adhesion molecule‐1 and human histocompatibility leucocyte antigens Class I. The present study describes similar outcomes when the same sequential intercellular adhesion molecule‐based protocol is applied to murine B16‐F10 melanoma cells as well as preclinical studies using the B16‐F10 model as a poorly immunogenic melanoma. Thus, treating B16‐F10 cells or a highly expressing B7‐1 transfected subline (B16‐F10/B7−1 hi) by priming with interferon‐gamma for 24 h before adding interferon‐β for a further 48 h (interferon‐gamma 72/beta 48) increased expression of all three surface antigens, particularly major histocompatibility complex class I whose increased expression was sustained for several days. As a whole tumour cell vaccine, interferon‐gamma 72/beta 48 treated B16‐F10 cells produced greater levels of cytoxic T lymphocyte response compared to vaccines prepared from cells treated with a single type of interferon. Furthermore, B16‐F10 cells expressing high levels of B7‐1 and treated using the interferon‐gamma 72/beta 48 protocol (interferon‐gamma 72/beta 48‐treated B16‐F10/B7−1 hi) produced substantially increased cytoxic T lymphocyte responses with a fivefold greater synergy than the combined results of either interferon treated or B7‐1 expressing cells tested individually. The resulting CD8+ cytoxic T lymphocyte showed greater specificity for B16‐F10 cells with tenfold higher killing than for syngeneic EL‐4 lymphoma cells. Killing proceeded via the perforin‐mediated pathway. CTL responses were induced independent of CD4+ T helper cells. The majority of mice receiving interferon‐gamma 72/beta 48‐treated B16‐F10/B7−1 hi vaccine in vivo remained tumour free after challenge with 5 × 105 live B16‐F10 cells expressing intermediate B7‐1 levels. The novel strategy described will help enhance vaccine potency when applied clinically to prepare whole cell based cancer vaccine therapies.
Blood protein polymorphisms in native chicken breeds in Yunnan province of China
Authors: OKAMOTO Shin , INAFUKU Keiichiro , TING Zhu , MAEDA Yoshizane , HOU Dexing , TAMG Yang Feng , YUN Zhang Han , XU Wenbo , SHI Liming , HASHIGUCHI Tsutomu
Published: November 2003

Blood samples were collected from four native breeds (Chahua chicken, Xishuangbanna Game chicken, Wuding chicken, and Yangbi Huang chicken) in the Yunnan province of China, and their protein polymorphisms were analyzed by using electrophoresies. Out of 16 loci examined, polymorphisms were found in the following eight loci: plasma esterase, plasma amylase, plasma alkaline phosphatase, plasma albumin, plasma transferrin, plasma postalbumin, and hemoglobin. The other eight loci, erythrocyte lactate dehydrogenase, erythrocyte 6‐phosphogluconate dehydrogenase, erythrocyte phosphoglucomutase, erythrocyte phosphohexose isomerase, erythrocyte tetrazolium oxidase, erythrocyte malate dehydrogenase, erythrocyte esterase and hemoglobin, were monomorphic. The proportion of the polymorphic loci and the expected average heterozygosity were estimated as 0.438–0.500 and 0.141–0.174, respectively. A dendrogram was drawn according to the genetic distance, which was calculated by the Nei's genetic distance matrix, among four Chinese native breeds. The results indicated that Chahua, Wuding and Yangbi Huang chickens were genetically remote from Xishuangbanna Game chicken. Moreover, the genetic distance was calculated among the Sri Lankan, Bangladeshi and Nepalese native fowl populations, and another dendrogram was constructed. In the latter dendrogram, Chahua, Wuding and Yangbi Huang chickens were genetically closer to Sri Lankan and Bangladeshi native fowls than Xishuangbanna Game chicken.
Number of nitrate‐ and nitrite‐reducing Selenomonas ruminantium in the rumen, and possible factors affecting its growth
Authors: YOSHII Takahiro , ASANUMA Narito , HINO Tsuneo
Published: November 2003

The cell number of Selenomonas ruminantium (S. ruminantium) that reduces nitrate and nitrite in the rumen was usually 8–10% of the total number of S. ruminantium (an order of 106/mL). The percentage was not affected by the roughage/concentrate ratio or nitrate content of the diet in 2 weeks. However, feeding a high‐nitrate diet for 12 weeks increased the percentage. The percentage of lactate‐using S. ruminantium, such as the ssp. lactilytica, was less than 1% of the total number of S. ruminantium. No S. ruminantium was found that used formate as an electron donor for nitrate and nitrite reduction. Lactate and H2 appeared to be important for nitrate and nitrite reduction by S. ruminantium. Nitrate reduction by S. ruminantium was enhanced by the coexistence of amylolytic bacteria in a medium containing starch, and as a result, nitrite accumulation increased. Coexistence of cellulolytic bacteria facilitated the growth of S. ruminantium in a medium containing cellulose, and consequently increased nitrite reduction. In order to suppress nitrite accumulation in the rumen, it may be important to enhance fiber digestion.
Reducing effect of dietary anacardic acid on body fat pads in rats
Authors: TOYOMIZU Masaaki , OKAMOTO Katsuyuki , ISHIBASHI Teru , NAKATSU Tetsuo , AKIBA Yukio
Published: November 2003

We have previously shown that anacardic acid has an uncoupling effect on oxidative phosphorylation in rat liver mitochondria using succinate as a substrate (Toyomizu et al. 2000). In the present study, in order to clarify whether or not anacardic acid could be used advantageously as a special feed/food supplement to reduce fat deposition through the uncoupling action, two sets of experiments were conducted to determine quantitatively the effect of dietary anacardic acid (0.1% w/w) supplementation. More specifically, effects on growth, feed efficiency, fattening, and levels of several constituents of blood serum in rats fed normal and low protein–high carbohydrate (CHO) diets were examined. There were no significant differences in bodyweight gain, feed consumption and feed efficiency among the experimental groups. For the total fat pad content, including inguinal and epididymal fat, significant interaction was shown between both treatments: dietary anacardic acid at 0.1% w/w significantly decreased the total fat pad content in rats fed the CHO diet, but not in rats fed the normal diet. Weights of heart, spleen and brown adipose tissue were not affected by either the dietary treatment or anacardic acid, while both liver and kidney weights decreased with feeding of anacardic acid at 0.1% w/w, but were not affected by the CHO diet. Anacardic acid supplementation in the diet had no effect on serum glutamic oxaloacetic transaminase, alkaline phosphatase or lactate dehydrogenase levels, suggesting that the dysfunction of liver or kidney may not be induced by dietary anacardic acid. The results of the present study reveal a unique function of anacardic acid in that, for dietary conditions enhancing body fat deposition, that is consumption of a diet high in carbohydrates, dietary anacardic acid has the potential to decrease body fat deposition. A possible mechanism for differences observed in anacardic acid‐induced regulation of body fat pad content between rats fed the normal and CHO diets, based on uncoupling action of anacardic acid on the mitochondrial oxidative phosphorylation, is discussed.
Systolic time intervals assessed by 2‐D echocardiography and spectral Doppler in the horse
Authors: LIGHTOWLER Carlos , PICCIONE Giuseppe , FAZIO Francesco , PIDAL Gabriela , CATTÁNEO Marìa Laura
Published: November 2003

In the present study, the ‘acoustic windows’ for the measurement of the left ventricular systolic time intervals is studied by means of 2‐D echocardiography and cardiac Doppler ultrasonography, and the normal values in the horse (n = 112) are determined. The left ventricular isovolumetric contraction time, the pre‐ejection period (PEP), as well as the left ventricular ejection time (LVET) have been measured, and the values of the left ventricular total electromechanical systole (LVTES) and the PEP‐to‐LVET ratio have been calculated. It has been established that the most suitable window for the measurement of the aforementioned indices in 2‐D echocardiography is the right parasternal window in a view in short axis at the level of the cardiac base to measure the aortogram. In Doppler ultrasonography, the preferred window is the left parasternal using the five chambers apical view. The following values have been acquired: PEP = 0.071 ± 0.01 s; LVET = 0.532 ± 0.097 s; LVTES = 0.6 ± 0.1 s and PEP‐to‐LVET = 0.138 ± 0.025 measured by 2‐D echocardiography and PEP = 0.068 ± 0.009 s; LVET = 0.527 ± 0.076 s; LVTES = 0.598 ± 0.098 s and PEP‐to‐LVET = 0.131 ± 0.01 measured by Doppler ultrasonography.
Sex differences in stress responses to transportation in goats: Effects of gonadal hormones
Authors: AOYAMA Masato , NEGISHI Akihito , ABE Akiko , MAEJIMA Yuko , SUGITA Shoei
Published: November 2003

The present study examined sex differences and the involvement of gonadal hormones in stress responses caused by road transportation in Shiba goats. In experiment 1, we investigated the stress responses of males and females to transportation. Plasma levels of cortisol (Cor) significantly increased during 1 h of transportation, and those in females were significantly higher than those in males. Plasma glucose (Glu) and free fatty acid (FFA) levels also increased similarly in both females and males by transportation, and there were no sex differences. Food intake following transportation decreased only in males compared with that in the basal session, in which the animals were not transported. Experiment 2 examined the involvement of gonadal hormones in stress responses to transportation using castrated males. Goats were given cholesterol (Cho), 5α‐dihydrotestosterone (DHT) or 17β‐estradiol (Es). The plasma Cor levels increased during transportation regardless of hormone treatment, and those in DHT treated goats were significantly lower than those in Cho or Es treated animals. Plasma Glu and FFA levels also increased during transportation, regardless of hormone treatment, and there were no differences between treatments. Food intake following transportation was significantly lower than that in the basal session only in goats given DHT. In conclusion, gender affects Cor secretion that is increased by transportation and the decrease of food intake following transportation in Shiba goats, and the major cause of these differences is androgen.
Isolation of vancomycin‐resistant enterococci from pigs in Japan
Authors: SAKAI Yuri , TSUKAHARA Takamitsu , USHIDA Kazunari
Published: November 2003

Forty vancomycin‐resistant enterococci (VRE) were isolated from feces of pigs in one pig farm. Two strains were further elucidated and these were biochemically identified as Enterococcus faecium possessing the vanB gene. These isolates showed high resistance to vancomycin and nine other antibiotics. This is the first report of VRE contamination in pigs in Japan.
Prolactin receptor gene expression in rat splenocytes and thymocytes during oestrous cycle, pregnancy and lactation
Authors: Güneş H. , Mastro A. M.
Published: November 2003

Much evidence suggests that prolactin (PRL) has an immunoregulatory function. Part of this evidence is that the receptors for PRL are present on lymphocytes. Probably the effects of PRL on cells of the immune system depend on the level and specific forms of PRL‐R present on the target cells. Therefore, PRL‐R expression at both protein and mRNA levels was examined during oestrous cycle, pregnancy and lactation using Western blotting and PCR analysis. Antibody to the long form of PRL‐R detected 84 and 42 kDa protein bands in the spleen but only 84 kDa band in the thymus. The expression pattern of these two protein bands was different in the spleen, suggesting that these two isoforms of PRL‐R long form are differentially regulated by the hormones of oestrous cycle. In addition, depending on the tissue, the level of mRNA for the short and long forms of PRL‐R showed a significant change at different stages of oestrous cycle. Moreover, 42 and 84 kDa PRL‐R bands were detected in both spleen and thymus throughout the pregnancy and lactation; however, the expression pattern of 84 kDa protein band was different between tissues. This finding suggests that each tissue exhibits differential response to hormones which affect PRL‐R content.
Screening for Down's syndrome
Authors: Chard T.
Published: November 2003

Down's syndrome (DS) is the commonest single cause of severe mental retardation in children. It can be diagnosed antenatally by chorionic villus sampling (CVS) or amniocentesis followed by karyotyping. At one time the sole indication for these invasive procedures was maternal age: typically women above age 35. However, this led to the detection of only some 30% of cases of DS at best. In the past ten years a series of biochemical and other abnormalities have been noted in Down's pregnancies and these form the basis for new screening programmes. The most familiar of the biochemical abnormalities are elevated levels of maternal serum human chorionic gonadotrophin (hCG), and reduced levels of α‐fetoprotein (AFP) and oestriol (E3). Changes are also noted in a number of other fetoplacental products. The underlying mechanism of these changes is unknown: suggestions include the possibility that a Down's syndrome pregnancy is relatively ‘immature’, or that there is a fetal–placental imbalance.
Evidence for the Bauman variant in Kallmann’s syndrome
Authors: Kadva Aban , Li Di Wei , Djahanbakhch Ovrang , Monson John , Silman Robert
Published: November 2003

BACKGROUND AND OBJECTIVE Idiopathic hypogonadotrophic hypogonadism (IHH) is a condition of gonadotrophin releasing hormone (GnRH) deficiency. IHH associated with anosmia is Kallmann’s syndrome. A variant has been described by Bauman where a patient with Kallmann's syndrome apparently regained normal hypothalamo‐pituitary function 2 years after the initial diagnosis. GnRH secretory activity can be assesed by measuring LH pulsatility. Our objective was to define the pattern of LH pulsatility in men with IHH and Kallmann’s syndrome compared with those of normal controls, and to determine whether there is evidence for a Bauman variant of Kallmann's syndrome.

DESIGN Patients with IHH and Kallmann’s syndrome were recruited from the endocrine clinic. Long‐term hormone replacement therapy was discontinued. LH pulsatility was determined.

PATIENTS Three men with IHH, 3 men with classical Kallmann’s syndrome and 5 normal male volunteers.

MEASUREMENTS Baseline serum FSH, LH and testosterone. Intensive blood sampling every 10 minutes for serum LH from 1000 to 1600 h during the day and 2200 to 0400 h during the night to measure LH pulsatility.

RESULTS The volunteer group showed normal LH pulsatility. In the patient group, LH secretion was apulsatile in one, showed significantly diminished amplitude in four, and there was normal pulsatility in one patient which remained normal 5 months later.

CONCLUSION Three patients with idiopathic hypo‐gonadotrophic hypogonadism and 2 with Kallmann's syndrome had variable degrees of GnRH deficiency. One patient with Kallmann's syndrome had apparently normal GnRH activity, which remained normal 5 months later. This patient appears to have the Bauman variant of Kallmann's syndrome.
Second trimester screening for Down's syndrome using maternal serum dimeric inhibin A
Authors: Wallace Euan M. , Swanston Ian A. , McNeilly Alan S. , Ashby J. Peter , Blundell Gillian , Calder Andrew A. , Groome Nigel P.
Published: November 2003

BACKGROUND AND OBJECTIVE Prenatal maternal serum screening for Down's syndrome has become an important and established part of modern antenatal care. Previously it has been reported that non‐specific immunoreactive inhibin may be useful in this context. Using a novel assay we have evaluated dimeric inhibin A as a possible second trimester marker of Down's syndrome.

METHODS From 1992–1993 records, stored sera from women with Down's affected pregnancies and chromosomally normal control pregnancies were identified and retrieved for analysis. These sera had been prospectively collected at 15, 16 and 17 weeks gestation.

SUBJECTS Records revealed 21 women who had had a Down's syndrome pregnancy and who also had serum available for analysis. Sera from 150 chromosomally normal controls, matched for gestation and duration of storage, were also retrieved

MEASUREMENTS Dimeric inhibin A was measured using a recently developed two‐site enzyme‐linked immunoassay. This employs a capture anti inhibin βA‐subunit monoclonal antibody, covalently bound to a microtitre plate and a second anti inhibin α‐subunit antibody conjugated to alkaline phosphatase, allowing detection.

RESULTS The mean (95% CI) maternal serum dimeric inhibin A in the samples from control pregnancies was 237 (201.5–273.4) ng/l, 266.9 (235.4–298.5) ng/l and 207.2 (178.5–235.9) ng/l at 15, 16 and 17 weeks gestation respectively. Expressing the results from the Down's samples as multiples of the normal median (MoM), the median (95% CI) MoM was 2.6 (2.25–3.57), significantly higher than the controls (P < 0.0001, Mann–Whitney U‐test). In the sample set tested, for a given false positive rate of 5.3% inhibin A alone afforded a detection rate of 62%, detecting cases previously undetected by routine screening.

CONCLUSIONS Dimeric inhibin A appears to be a promising new marker for the prenatal detection of Down's syndrome. Further prospective evaluation and assessment with other established markers would now be merited.
The relation between thyroid function and nutritional status in HIV‐infected patients
Authors: Ricart‐Engel Wilfredo , Fernández‐Real José Manuel , González‐Huix Ferran , Del Pozo Milagros , Mascaró Jaume , García‐Bragado Fernando
Published: November 2003

OBJECTIVE The effects of human immunodeficiency virus (HIV) infection on thyroid function have been reported in only a few studies with discrepant results. The aim of this study was to assess the relation between nutritional status and thyroid function in HIV infected patients.

DESIGN Prospective, cross‐sectional study.

SETTING A 500‐bed teaching and referral hospital serving a population of 450 000.

PATIENTS Seventy‐five consecutive HIV infected patients between 21 and 40 years of age (mean 31.8 ± 0.9 years).

MEASUREMENTS Nutritional status was evaluated using the body mass index (BMI), triceps skinfold thickness (TSF), mid‐arm muscle circumference (MAMC), and serum albumin concentration (SA). Hormone assays for serum T4, free thyroxine index (FTI), T3, reverse triiodothyronine (rT3), thyroxine‐binding globulin (TBG), TSH and simultaneous CD4 lymphocyte counts were determined in all patients.

RESULTS Clinical stage was significantly related to nutritional status (P = 0.0001 for BMI, P = 0.0002 MAMC). The more poorly nourished groups had low mean serum T3 and rT3 levels, particularly for muscular (P = 0.0001 for T3 and P = 0.0076 for rT3) and visceral (P = 0.00001 for T3 and P = 0.0021 for rT3) protein compartments. Multivariate analysis showed that two factors, SA and MAMC, correlated significantly and independently with serum T3 and rT3.

CONCLUSIONS A close relation exists between serum thyroid hormone levels and nutritional status in HIV infected patients. These patients are probably euthyroid and the abnormal findings in the thyroid function tests are thus a reflection of the severity of illness.
A novel mutation in the coding region for neurophysin‐II is associated with autosomal dominant neurohypophyseal diabetes insipidus
Authors: Rauch Frank , Lenzner Claudia , Nürnberg Peter , Frömmel Cornelius , Vetter Ulrich
Published: November 2003

OBJECTIVE Autosomal dominant neurohypophyseal diabetes insipidus (ADNDI) is a rare cause of diabetes insipidus, in which AVP serum levels are insufficient. AVP is synthesized along with neurophysin‐II (NPII) as an AVP‐NPII precursor polypeptide in the hypothalamus. After proteolytic cleavage during axonal transport, AVP and NPII are reassembled and stored loosely bound to each other in the posterior pituitary until both are released into the circulation. In this study, we investigated the genetic basis of ADNDI in a German kindred with 10 affected members spanning three generations.

DESIGN Genomic DNA was isolated from peripheral blood leucocytes. The entire coding region of the AVP‐NPII gene of one of the affected persons was amplified by polymerase chain reaction (PCR) and subjected to nucleotide sequence analysis. Sequencing results were confirmed by restriction enzyme analysis of PCR products.

PATIENTS Six affected and two unaffected members of a family with ADNDI and 54 unrelated healthy control subjects were studied.

RESULTS The index patient was found by direct sequencing to be heterozygous for a G to T transversion at nucleotide position 1884 (exon 2) of the AVP‐NPII gene. This mutation introduced a new recognition site for the restriction enzyme Ava II, which was used to test for the presence of the mutation in other family members and in control subjects. The mutation was detected in all family members with ADNDI, but was not found in unaffected family members or in control subjects. The mutation encodes a valine in place of the normal glycine at amino acid 65 of NPII, which is known to be highly conserved during evolution.

CONCLUSIONS In this family, the autosomal dominant neurohypophyseal diabetes insipidus phenotype cosegregates with a point mutation in a region of the AVP‐neurophysin‐II gene which codes for the carboxy‐terminal domain of neurophysin‐II. Although the altered amino acid is not directly involved in AVP binding, the mutation might lead to conformational changes that impair the dimerization of neurophysin‐II molecules. This could in turn affect the AVP binding affinity of neurophysin‐II or might interfere with the transport of the AVP‐neurophysin‐II precursor in the AVP‐producing cells of the hypothalamus.
The effect of β‐endorphin on basal and insulin‐hypoglycaemia stimulated levels of hypothalamic‐pituitary‐adrenal axis hormones in normal human subjects
Authors: Inder W.J. , Livesey J.H. , Ellis M.J. , Evans M.J. , Donald R.A.
Published: November 2003

OBJECTIVE It has been demonstrated that β‐endorphin reduces CRH production and hypoglycaemia‐induced ACTH secretion in the rat. We aimed to determine whether supraphysiological levels of β‐endorphin inhibit the ACTH and CRH response to insulin‐induced hypoglycaemia in human subjects.

DESIGN Plasma glucose, prolactin, cortisol, ACTH, CRH and AVP were measured at intervals over a 3‐hour period. Intravenous β‐endorphin 5 mg/50 ml or an equal volume of normal saline was infused between 30 and 90 minutes, with soluble insulin 0.15 units/kg administered i.v. at 60 minutes in a cross‐over design.

SUBJECTS Six healthy male volunteers aged 20–35 years.

MEASUREMENTS Prolactin was measured by a fluoroimmunometric assay, ACTH, CRH and AVP by radioimmunoassay, and cortisol was measured by enzyme‐linked immunosorbent assay. Haemodynamic measurements were recorded prior to each blood sample. Results are expressed as mean ± standard error of the mean.

RESULTS β‐Endorphin resulted in a significant decrease in baseline cortisol (P < 0.05) but not ACTH. Plasma glucose (P < 0.001) and CRH (P < 0.05) and PRL (P < 0.05) increased significantly during β‐endorphin compared to normal saline. After insulin administration, glucose reached a similar nadir during β‐endorphin and normal saline (2.1 ± 0.1  and 1.9 ± 0.15 mmol/l, respectively) but the fall in plasma glucose was delayed during β‐endorphin (P < 0.01 by ANOVA). This resulted in a significantly altered time‐course for the ACTH and cortisol responses (P < 0.05 for each), but no difference overall in the magnitude of the response. In contrast, neither the timing nor the magnitude of the CRH and AVP responses were affected. Prolactin also reached a similar peak value after the administration of insulin, while the haemodynamic responses to hypoglycaemia were not significantly altered during β‐endorphin.

CONCLUSIONS While β‐endorphin has been shown to be inhibitory to basal ACTH and cortisol secretion in humans, we note a significant increase in plasma CRH in response to β‐endorphin, which may be arising from a peripheral source. Intravenous β‐endorphin increases plasma glucose and delays the onset of hypoglycaemia following insulin but does not result in significant inhibition of the ACTH and cortisol response. This may reflect the poor penetration of β‐endorphin into the central nervous system, although a hypothalamic effect of β‐endorphin is implied by the increased PRL. The significantly delayed time course in ACTH and cortisol secretion noted during β‐endorphin is not explained by a later response of either CRH or AVP. Although peripheral levels of these hormones may be a relatively insensitive measure of hypothalamic function, an additional factor may influence ACTH release during hypoglycaemia.
The effect of oophorectomy and hormone replacement on neurohypophyseal hormone secretion in women
Authors: Forsling Mary L. , Harriet C. , Anderson M. , Wheeler M.J. , Shanti Raju K.
Published: November 2003

OBJECTIVE There is evidence to suggest that the release of neurohypophyseal hormones may be influenced by the circulating concentrations of gonadal steroids.We therefore monitored this relationship in women undergoing prophylactic bilateral oophorectomy at the time of hysterectomy with subsequent hormone replacement therapy and compared it with that in women undergoing hysterectomy with conservation of ovaries

DESIGN Patients were randomly allocated to receive either transdermal oestradiol patches, 0.05 mg/day, or subdermal implants containing either 50 mg oestradiol or 50 mg oestradiol with 100 mg testosterone. Blood samples for determination of plasma hormone concentrations, electrolytes and osmolality were obtained immediately before and after surgery and then at two‐monthly intervals for 8 months and finally at 12 months.

MEASUREMENTS Free oestradiol, vasopressin and oxytocin were measured by radioimmunoassay.

RESULTS Vasopressin concentrations were found to fall after surgery in oophorectomized women, but not in those with ovaries. There were no changes in fluid balance to account for the reduced plasma vasopressin concentrations. During treatment oestradiol appeared to enhance and testosterone to suppress vasopressin release. Oophorectomy had no significant effect on plasma oxytocin concentrations, but in the groups receiving oestradiol implants concentrations fell significantly at 8 and 12 months compared with the value at 6 days.

CONCLUSION The observed changes in plasma vasopressin concentrations were consistent with the observations in experimental animals and provide evidence that vasopressin release in the human is influenced by gonadal steroids.
Continuous subcutaneous infusion of low dose growth hormone decreases serum sex‐hormone binding globulin and testosterone concentrations in moderately obese middle‐aged men
Authors: Oscarsson Jan , Lindstedt Göran , Lundberg Per‐Arne , Edén Staffan
Published: November 2003

OBJECTIVE  Sex‐hormone binding globulin (SHBG) is a liver derived protein whose concentration has been shown to be affected by a number of factors. The aim of the present study was to investigate the possible effect of increased basal GH concentrations on serum concentrations of SHBG, testosterone and thyroid hormones.

DESIGNS Recombinant human growth hormone (rhGH) was given as a continuous subcutaneous infusion in a low dose (0.02 U/kg/day) over a period of 14 days in an open study.

PATIENTS Eight middle‐aged (42–59 years) overweight (body mass index 26.1–33.8 kg/m2) but otherwise healthy men were studied.

MEASUREMENTS Blood samples were obtained after an over‐night fast before and after 2, 7 and 14 days of treatment. Serum was separated and stored at −20°C until assay.

RESULTS Serum GH concentrations increased to a steady level of 2–4 mU/l. Serum SHBG concentration decreased between 2 and 7 days of treatment and serum testosterone concentration changed in parallel. There was no change in the ratio between serum SHBG and serum testosterone. Serum T4 and free T4 concentrations decreased, and that of T3 increased as a result of continuous GH infusion. Simple correlations between changes in SHBG concentrations and other hormonal changes showed positive significant correlations between changes of SHBG and of testosterone.

CONCLUSIONS Low dose continuously infused GH resulted in a parallel decrease in serum SHBG and testosterone concentrations. Thyroid hormone concentrations were affected in a similar way to that previously demonstrated following daily injections of GH.
Low and conventional dose transdermal oestradiol are equally effective at preventing bone loss in spine and femur at all post‐menopausal ages
Authors: Evans S. F. , Davie M. W. J.
Published: November 2003

OBJECTIVES We wished to appraise the effectiveness of hormone replacement therapy (HRT) in early (<67 years) and late (>67 years) post‐menopausal women referred to a metabolic outpatient clinic for assessment of their bone status. Because older women often experience side‐effects with conventional HRT, a low dose preparation (Estraderm 25) was also compared with conventional HRT (Estraderm 50).

DESIGN AND SETTING Since all patients were symptomatic, the investigation was open and not placebo controlled. Patients were offered HRT and told about the two dosages. If they wished to use HRT, allocation of dosage was made randomly unless there were reasons to use a specific dose.

PATIENTS One hundred and ninety‐six women were studied over 1 or 2 years with 80 reaching 3 years of treatment. Patients were divided into those under 67 years and those over 67 years at the start of treatment. Each group was further divided into those taking Estraderm 25 and those taking Estraderm 50 with norethisterone if appropriate.

MEASUREMENTS Bone mineral density (BMD) was measured (DXA, Hologic) at the lumbar spine and femoral neck at 0 year (196 patients), at 1 year (169 patients), at 2 years (139 patients) and at 3 years (80 patients). Patients losing bone were expressed as those whose 3 year BMD was lower than initial or as those whose BMD at 3 years had fallen by more than twice the coefficient of variation for that site (non‐responders).

RESULTS In lumbar spine, BMD increased maximally in the first year in all groups and the gain was maintained after 3 years. The change was similar whether patients were divided by age or dosage. For those on Estraderm 25, mean change after 3 years was 8.1 ± 6.8% and on Estraderm 50, 9.0 ± 8.3% (combined 8.7 ± 7.8%). Only 3.9% of patients were non‐responders at the lumbar spine after 3 years. At femoral neck, changes were significant at 3 years only in the Estraderm 25 >67 years and Estraderm 50 <67 years groups and averaged 2.3 ± 5.4% for all patients. At the femoral neck, 10.4% of patients were non‐responders after 3 years. Percentage change of BMD over 3 years at lumbar spine correlated with that at the femoral neck (r = 0.56). Percentage change of BMD at lumbar spine over 3 years correlated with menopausal age (r = 0.295). No relation was found between dosage of Estraderm/kg body weight and response of BMD at either site.

CONCLUSIONS Transdermal oestrogen is effective at preventing bone loss in the spine at all post‐menopausal ages and is capable of doing this in low dosage. Prevention of bone loss at the femoral neck is less certain and the average change in BMD over 3 years was significantly lower (P < 0.001) than in the lumbar spine. Use of Estraderm 50 is not associated with a greater response of bone mass and there was no evidence of an increasing BMD response as oestradiol dosage/kg body weight increased.
Growth hormone deficiency and hypogonadism in a patient with multiple sclerosis
Authors: Davies J. S. , Hinds N. P. , Scanlon M. F.
Published: November 2003

We describe the case of a 30‐year‐old female patient with a 7‐year hisory of multiple sclerosis, who presented with an 18‐month history of secondary amenorrhoea and vague symptoms which included poor sleep and impaired concentration. Endocrine investigations revealed hypogonadotrophic hypogonadism and GH deficiency, a probable consequence of a hypothalamic plaque. This is the first report of hypogonadotrophic hypogonadism and GH deficiency occuring in conjunction with multiple sclerosis. As such, it should raise suspicion of endocrine dysfunction occurring in a condition with such a vast spectrum of disability as multiple sclerosis.
Oropharyngeal regulation of water balance in polydipsic schizophrenics
Authors: Goldman Morris B. , Robertson Gary L. , Hedeker Donald
Published: November 2003

OBJECTIVE Disordered water balance causes substantial morbidity in a subset of schizophrenics and is the consequence of unexplained defects in the regulation of fluid intake and antidiuretic function. We aimed to determine whether oropharyngeal regulation of water balance is altered in these patients.

DESIGN A 2‐hour infusion of 3% saline, followed 35 minute later by an oral water load (10 ml/kg over 3 minutes).

PATIENTS Age and sex‐matched polydipsic schizophrenics with (n = 5) and without (n = 8) hyponatraemia; non‐polydipsic schizophrenics (n = 6); and normal controls (n = 13).

MEASUREMENTS Plasma osmolality, sodium, AVP, and reported desire for water (expressed in cups), determined prior to, and for 30 minutes following, the water load.

RESULTS Plasma osmolality and sodium were consistently lower in the hyponatraemics (P<0.01). Significant changes did not occur until 20 and 25 minutes, respectively, after oral water loading, and were similar across the four groups. AVP levels were consistently lower in the two polydipsic groups (P<0.001), fell within 5 minutes after drinking and then levelled off. Neither the acute fall nor the overall pattern of the responses differed across groups. Subjective desire for water also decreased within 5 minutes of drinking, and also to a similar extent, in the four groups. Subsequent levels remained suppressed in the non‐polydipsic groups, but rebounded toward baseline in the two polydipsic groups. Thus the overall patterns differed (P<0.05). At the end of the study, ad lib intake correlated significantly with reported desire for water (r = 0.51, P<0.002).

CONCLUSIONS The oropharyngeal regulation of water intake is disrupted in polydipsic schizophrenics with and without hyponatraemia. In contrast, the oropharyngeal regulation of AVP secretion appears preserved in the hyponatraemic subset. Previously observed elevations in plasma AVP in this subset are thus unlikely to be related to defects in oropharyngeal regulation.