Unsuspected ileal stenosis causing obscure GI bleeding in patients with previous abdominal surgery--diagnosis by capsule endoscopy: a report of two cases

Peri-anastomotic ulcerations may occur in patients with previous abdominal surgery. They may present only with obscure GI bleeding. We report two cases in whom capsule endoscopy identified postsurgical stenoses with ulcers as the cause of obscure GI bleeding. Case 1. A 57-year-old male operated on in 1970 for a post-traumatic diaphragm hernia followed by displacement of the caecum in the upper left abdominal quadrant. Case 2. A 32-year-old female with a salpingectomy for tuberculosis (1978) followed by segmental ileal resection for intestinal obstruction. Both patients had undergone extensive work-up including bidirectional endoscopies and enteroclysis with negative results. Capsule endoscopy with the GIVEN diagnostic system was done. Ileal stenoses with mucosal ulcers in dilated prestenotic loops were observed in both cases. The capsule was retained at the stenosis site, requiring ileal resection and anastomosis. Pathology reports showed mucosal ulcers. In case 2, tuberculosis was ruled out by tissue and faecal polymerase chain reaction and culture. Ileal stenoses with prestenotic ulcerations causing GI bleeding may occur in patients with previous abdominal surgery. Capsule endoscopy may clarify the diagnosis and shorten the diagnostic work-up. However, these patients should be warned that capsule retention requiring surgery might occur.

90Y-DOTA-D-Phe1-Try3-octreotide in therapy of neuroendocrine malignancies

Somatostatin receptors type 2 (sst(2)) are expressed in high concentration on numerous neudoendocrine tumors. The successful use of radiolabeled somatostatin analogs in imaging promoted further studies in utilizing them in radiopeptide therapy. The somatostatin analog [(90)Y-DOTA-D-Phe(1)-Try3]octreotide (DOTATOC) (DOTA: 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) possesses favorable characteristic for its therapeutic use; shows high affinity for sst(2), moderately high affinity for sst(5), and intermediate affinity for sst(3); high hydrophilicity; stable and facile labeling with (111) In and (90) Y. In this article we report our experience with (90)Y-DOTATOC in neuroendocrine tumors. Eighty-seven patients with neuroendocrine tumors were treated with a cumulated activity ranging from 7.4 to 20.2 GBq. Most patients responded with stabilization of disease (48%); however, objective responses were observed in 28% of patients (5% complete response). No major acute reactions were observed up to the activity of 5.55 GBq per cycle. The dose limiting was bone marrow toxicity and the maximal tolerated dose was defined as 5.18 GBq.

Molecular typing of Lactobacillus delbrueckii of dairy origin by PCR-RFLP of protein-coding genes

Thirty-five strains of Lactobacillus delbrueckii subsp. lactis and subsp. bulgaricus isolated from dairy products were typed by restriction fragment length polymorphism (RFLP) of protein-coding genes. The strains were analysed by RFLP of PCR amplified, infragenic fragments of the following housekeeping genes: beta-galactosidase, lactose permease, and proline dipeptidase. Sequencing of the variable regions of the 16S rDNA was then performed on a reduced number of strains. PCR-RFLP analysis evidenced wide strain heterogeneity. Strains were grouped into genotypes according to both subspecies assignment and infra-species genetic polymorphism. This polymorphism was related to the presence of microbial groups within subspecies populations. The low infra-species sequence polymorphism detected in the variable region of the 16S rRNA gene did not enable to group the strains with the same sensitivity reached by PCR-RFLP of protein-coding genes. PCR-RFLP of protein-coding genes applied to L. delbrueckii seems a promising tool to evaluate microbial diversity within bacterial subpopulations. Differences among bacterial subpopulations based upon molecular heterogeneity in protein-coding genes would enable to better understand the role of strains from different ecological niches.

Highly branched poly(L-lysine)

This paper describes the synthesis of several novel water-soluble highly branched polypeptides. The synthesis starts with the ring-opening polymerization of epsilon-benzyloxycarbonyl-l-lysine N-carboxyanhydride (Z-Lys NCA) or epsilon-trifluoroacetyl-l-lysine N-carboxyanhydride (TFA-Lys NCA), followed by end functionalization of the peptide chain with N(alpha),N(epsilon)-di(9-fluorenylmethoxycarbonyl)-l-lysine (N(alpha),N(epsilon)-diFmoc Lys). Deprotection of the N(alpha),N(epsilon)-diFmoc Lys end group affords two new primary amine groups that can initiate the polymerization of a second generation of branches. Repetition of this ring-opening polymerization-end functionalization sequence affords highly branched poly(epsilon-benzyloxycarbonyl-l-lysine) (poly(Z-Lys)) and poly(epsilon-trifluoroacetyl-l-lysine) (poly(TFA-Lys)) in a small number of straightforward synthetic steps. Removal of the side-chain protective groups yields water-soluble and highly branched poly(l-lysine)s, which may be of potential interest for a variety of medical applications.

Genetic diversity and technological properties of Streptococcus thermophilus strains isolated from dairy products

AIMS

To evaluate the genetic diversity and the technological properties of 44 strains of Streptococcus thermophilus isolated from dairy products. Methods

METHODS AND RESULTS

Strains were analysed for some relevant technological properties, i.e. exopolysaccharide (EPS) production, growth kinetic in skim milk medium, urease activity and galactose fermentation. The EPS production, determined by evaluating the colour of the colonies grown in ruthenium red milk agar, was observed in 50% of the analysed strains. Urease activity, determined by colorimetric and conductimetric methods, showed that 91% of the isolates, all except four, could hydrolyse urea. A conductimetric approach was also used for the evaluation of the overall metabolic behaviour in milk of Strep. thermophilus strains and the differences observed allowed grouping of the strains in seven different clusters. A total of 11 strains were able to produce acid in presence of galactose. Genetic diversity of Streptococcus thermophilus strains, evaluated by Random Amplified Polymorphic DNA fingerprinting (RAPD) and amplified epsC-D restriction analysis, allowed the identification of 21 different genotypes.

CONCLUSIONS

Comparison between the genotypic and phenotypic data highlights an interesting correlation between some important technological properties and well-defined genotypes.

SIGNIFICANCE AND IMPACT OF THE STUDY

The genetic and technological characterization carried out on several Strep. thermophilus strains of dairy origin should expand the knowledge on this important lactic acid bacteria species and lead to a simple, rapid, and reliable identification of strains on the basis of well-defined biotechnological properties.

Set-up of large laboratory-scale chromatographic separations of poly(ethylene glycol) derivatives of the growth hormone-releasing factor 1-29 analogue

In this paper we report the scale-up of the purification of poly(ethylene glycol) (PEG) derivatives of the growth hormone-releasing factor 1-29, from laboratory scale (100 mg of bulk starting material) to larger scale (3 g of bulk), through the use of a cation-exchange TSK-SP-5PW chromatographic column. A one-step purification process capable of purifying large amounts of mono-PEGylated GRF species from the crude reaction mixture was developed. A simple, straightforward stepwise gradient elution separation was developed at laboratory scale and then scaled up with a larger column packed with a chromatographic resin with the same chemistry which maintained the laboratory-scale separation profile. Active material recovery and material purity remained constant through the scale-up from the 13-microm stationary phase to the 25-microm larger column. Overall, the gram GRF equivalent/batch process scale showed to be quite reproducible, and could be considered as a good platform for scale up to production scale.

Pretargeted adjuvant radioimmunotherapy with yttrium-90-biotin in malignant glioma patients: a pilot study

In a previous study we applied a three-step avidin-biotin pretargeting approach to target 90Y-biotin to the tumour in patients with recurrent high grade glioma. The encouraging results obtained in this phase I-II study prompted us to apply the same approach in an adjuvant setting, to evaluate (i) time to relapse and (ii) overall survival. We enrolled 37 high grade glioma patients, 17 with grade III glioma and 20 with glioblastoma, in a controlled open non-randomized study. All patients received surgery and radiotherapy and were disease-free by neuroradiological examinations. Nineteen patients (treated) received adjuvant treatment with radioimmunotherapy. In the treated glioblastoma patients, median disease-free interval was 28 months (range=9-59); median survival was 33.5 months and one patient is still without evidence of disease. All 12 control glioblastoma patients died after a median survival from diagnosis of 8 months. In the treated grade III glioma patients median disease-free interval was 56 months (range=15-60) and survival cannot be calculated as only two, within this group, died. Three-step radioimmunotherapy promises to have an important role as adjuvant treatment in high grade gliomas, particularly in glioblastoma where it impedes progression, prolonging time to relapse and overall survival. A further randomized trial is justified.

Drosophila male meiosis as a model system for the study of cytokinesis in animal cells

Drosophila male meiosis offers unique opportunities for mutational dissection of cytokinesis. This system allows easy and unambiguos identification of mutants defective in cytokinesis through the examination of spermatid morphology. Moreover, cytokinesis defects and protein immunostaining can be analyzed with exquisite cytological resolution because of the large size of meiotic spindles. In the past few years several mutations have been isolated that disrupt meiotic cytokinesis in Drosophila males. These mutations specify genes required for the assembly, proper constriction or disassembly of the contractile ring. Molecular characterization of these genes has identified essential components of the cytokinetic machinery, highlighting the role of the central spindle during cytokinesis. This structure appears to be both necessary and sufficient for signaling cytokinesis. In addition, many data indicate that the central spindle microtubules cooperatively interact with elements of the actomyosin contractile ring, so that impairment of either of these structures prevents the formation of the other.

Genotypic and phenotypic heterogeneity of Streptococcus thermophilus strains isolated from dairy products

AIMS

Forty strains of Streptococcus thermophilus isolated from dairy products were identified and typed by a polyphasic approach which included phenotypic and genotypic criteria.

METHODS AND RESULTS

Strains were identified by sugar fermentation pattern and species-specific PCR. Phenotypic diversity was evaluated by a chemometric model taking into account some biochemical characteristics (e.g. acidifying and peptidase activities) of technological interest. Genotypic diversity was evidenced by PCR fingerprinting. The overall phenotypic and genotypic information was elaborated on a multivariate statistical basis by principal components analysis and cluster analysis, respectively. When acidifying and peptidase activities were considered, PCA indicated that most of the strains isolated from Pecorino Toscano cheese were separable from the others. Similarly, most of the starter culture strains tended to separate from the cheese isolates.

CONCLUSIONS

A wide strain heterogeneity among Strep. thermophilus strains isolated from dairy products was observed.

SIGNIFICANCE AND IMPACT OF THE STUDY

A computerized analysis of genotypic and phenotypic information could be applied successfully to differentiate and characterize reliably and rapidly isolates occurring in different dairy products and to comprehend the technological role of specific Strep. thermophilus strains in dairy technology.

Early and long-term results of surgical treatment of splenic artery aneurysms

BACKGROUND

This retrospective study was conducted to describe the presentation, surgical treatment, and follow-up of patients with splenic artery aneurysms.

METHODS

From 1982 to 2000, 1,952 patients with abdominal aneurysms were referred to our department; 15 had splenic artery aneurysms. None had ruptured. All were operated on.

RESULTS

Fourteen complete and 1 partial aneurysmectomies were carried out. Arterial continuity was restored in 10, by end-to-end anastomosis, and 4 had splenectomies. In 1 patient the spleen was preserved without arterial reconstruction. There were no deaths. Morbidity was restricted to 1 patient with a limited, asymptomatic splenic infarction. Eleven patients were followed up for a mean 19.7 months. No deaths or major complications were recorded. Reconstructed splenic arteries were patent in all cases without atrophy or new cases of splenic infarction.

CONCLUSIONS

Elective surgery for splenic artery aneurysms is safe. Arterial reconstruction allows good early and long-term results. In some cases splenectomy may be unavoidable.

Contribution of Gal- lactic acid bacteria to Saccharomyces cerevisiae metabolic activity in milk

The contemporaneous presence of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus affected the growth kinetics of Saccharomyces cerevisiae PZ2 and the metabolic products of their growth were quantitatively and qualitatively different from those produced by single strains inoculated alone. S. cerevisiae can grow in milk without using lactose or galactose. In particular, the presence of peptides seems to be sufficient to ensure its growth. The growth of S. cerevisiae with lactic acid bacteria is characterised by stimulatory effects that involve both yeast and bacteria. However, the release of galactose by lactic acid bacteria does not seem to be the core metabolic event of these stimulatory effects on S. cerevisiae.

Pre-targeted locoregional radioimmunotherapy with 90Y-biotin in glioma patients: phase I study and preliminary therapeutic results

The aim of this study was to determine the maximum-tolerated dose, of a pre-targeting three-step (3-S) method employing 90Y-biotin in the locoregional radioimmunotherapy (RIT) of recurrent high grade glioma, and to investigate the antitumor efficacy of this new treatment. Twenty-four patients with recurrent glioma underwent second surgical debulking and implantation of a catheter into the surgical resection cavity (SRC), in order to introduce the radioimmunotherapeutic agents [biotinylated monoclonal antibody (MoAb), avidin and 90Y-biotin]. Eight patients with anaplastic astrocytoma (AA) and 16 patients with glioblastoma (GBM) were injected with biotinylated anti-tenascin MoAb (2 mg), then with avidin (10 mg; 24 h later) and finally 90Y-biotin (18 h later). Each patient received two of these treatments 8-10 weeks apart. The injected activity ranged from 0.555 to 1.110 GBq (15-30 mCi). Dosage was escalated by 0.185 GBq (5 mCi) in four consecutive groups. The treatment was well tolerated without acute side effects up to 0.740 GBq (20 mCi). The maximum tolerated activity was 1.110 GBq (30 mCi) limited by neurological toxicity. None of the patients developed hematologic toxicity. In three patients infection occurred around the catheter. The average absorbed dose to the normal brain was minimal compared with that received at the SRC interface. At first control (after 2 months), partial (PR) and minor (MR) responses were observed in three GBM (1 PR; 2 MR) and three AA patients (1 PR; 2 MR) with an overall objective response rate of 25%. Stable disease (SD) was achieved in seven GBM and five AA patients (50%). There was disease progression in six GBM patients (25%), but in none of the AA patients. At the dosage of 0.7-0.9 GBq per cycle, locoregional 3-S-RIT was safe and produced an objective response in 25% of patients. Based on these encouraging results, phase II studies employing 3-S-RIT soon after first debulking are justified.

Carotid endarterectomy in rare bilateral carotid-vertebral anastomosis

In the embryo, the anterior and the posterior cerebral circulations are connected by several longitudinal anastomotic vessels. These anastomoses disappear progressively, until the carotid and vertebrobasilar systems are connected only by a pair of posterior communicating arteries. These embryonal anastomoses rarely persist in adults and may have an important physiologic role during carotid surgery. We report a case in which a patient with bilateral embryonal carotid-vertebral anastomoses underwent right carotid endarterectomy for asymptomatic internal carotid stenosis.

Differentiation of Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus delbrueckii subsp. lactis by SDS-PAGE of cell-wall proteins

AIMS

In the present study, a method based on SDS-PAGE fingerprinting of surface layer proteins was developed to identify Lactobacillus delbrueckii subsp. bulgaricus and subsp. lactis dairy isolates.

METHODS AND RESULTS

The two subspecies, identified by species-specific PCR, were characterized by different SDS-PAGE cell-wall protein profiles; subspecies bulgaricus showed one band of about 31 kDa which, in some cases, was observed at a doublet, and subspecies lactis showed one band of about 21 kDa or 18 kDa.

CONCLUSION

The sensitivity of this procedure for discriminating between the two subspecies was very high. The different types of SDS-PAGE profile for cell-wall proteins of the strains studied in this work did not seem to be correlated to the different dairies of origin.

SIGNIFICANCE AND IMPACT OF THE STUDY

The method appears to be an efficient taxonomic tool. It has the advantage of easy gel interpretation over fingerprinting of whole-cell protein extracts, and may be used as an alternative to established PCR-based techniques which, though rapid and safe, require expensive instruments and reagents.

The role of centrosomes and astral microtubules during asymmetric division of Drosophila neuroblasts

Drosophila neuroblasts are stem cells that divide asymmetrically to produce another large neuroblast and a smaller ganglion mother cell (GMC). During neuroblast division, several cell fate determinants, such as Miranda, Prospero and Numb, are preferentially segregated into the GMC, ensuring its correct developmental fate. The accurate segregation of these determinants relies on proper orientation of the mitotic spindle within the dividing neuroblast, and on the correct positioning of the cleavage plane. In this study we have analyzed the role of centrosomes and astral microtubules in neuroblast spindle orientation and cytokinesis. We examined neuroblast division in asterless (asl) mutants, which, although devoid of functional centrosomes and astral microtubules, form well-focused anastral spindles that undergo anaphase and telophase. We show that asl neuroblasts assemble a normal cytokinetic ring around the central spindle midzone and undergo unequal cytokinesis. Thus, astral microtubules are not required for either signaling or positioning cytokinesis in Drosophila neuroblasts. Our results indicate that the cleavage plane is dictated by the positioning of the central spindle midzone within the cell, and suggest a model on how the central spindle attains an asymmetric position during neuroblast mitosis. We have also analyzed the localization of Miranda during mitotic division of asl neuroblasts. This protein accumulates in morphologically regular cortical crescents but these crescents are mislocalized with respect to the spindle orientation. This suggests that astral microtubules mediate proper spindle rotation during neuroblast division.

Arrhythmogenic right ventricular dysplasia: cardiomyopathy current opinions on diagnostic and therapeutic aspects

Right Ventricular Dysplasia constitutes a genetic cardiomyopathy characterized by fibrous-adipose substitution of the right and rarely of the left ventricular myocardium. This disorder is associated with ventricular arrhythmias ranging from frequent ventricular ectopic beats, nonsustained and sustained ventricular tachycardia of left bundle branch morphology and sudden death. Therefore, the syndrome has been labelled Arrhythmogenic RVD Cardiomyopathy. Diagnostic criteria, preliminary genetic data, and clinical manifestations are summarized and critical addressed, using data from the literature and from our own experience. The most important aspects of the ECG in this syndrome are reviewed and stressed with particular attention to initial versus advanced clinical subsets. The typical anatomical abnormalities and biopsy or pathology material are presented.

Relationships between the central spindle and the contractile ring during cytokinesis in animal cells

During late anaphase and telophase, animal cells develop a bundle of antiparallel, interdigitating microtubules between the two daughter nuclei. Recent data indicate that this structure, called the central spindle, plays an essential role during cytokinesis. Studies in Drosophila and on vertebrate cells strongly suggest that the molecular signals for cytokinesis specifically emanate from the central spindle midzone. Moreover, the analysis of Drosophila mutants defective in cytokinesis has revealed a cooperative interaction between the central spindle microtubules and the contractile ring: when either of these structures is perturbed, the proper assembly of the other is disrupted. Based on these results we propose a model for the role of the central spindle during cytokinesis. We suggest that the interaction between central spindle microtubules and cortical actin filaments leads to two early events crucial for cytokinesis: the positioning of the contractile ring, and the stabilization of the plus ends of the interdigitating microtubules that comprise the central spindle. The latter event would provide the cell with a specialized microtubule scaffold that could mediate the translocation of plus-end-directed molecular motors to the cell's equator. Among the cargoes transported by these motors could be proteins involved in the regulation and execution of cytokinesis.

Molecular diversity within Lactobacillus helveticus as revealed by genotypic characterization

Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium that is used in the manufacture of Swiss type and long-ripened Italian cheeses, such as Emmental, Grana, and Provolone cheeses. Substantial differences in several technologically important characteristics are found among L. helveticus strains isolated from natural dairy starter cultures. In the present study we investigated the genotypic diversity of 74 strains isolated from different dairy cultures used for manufacturing Grana and Provolone cheeses and six collection strains. A restriction fragment length polymorphism analysis of both total genomic DNA and the 16S rRNA gene (ribotyping) was used as genotypic fingerprinting. A multivariate statistical analysis of the data enabled us to identify significant genotypic heterogeneity in L. helveticus. We found that genotypic fingerprinting could be used to distinguish strains; in particular, it was possible to associate the presence of specific strain genotypes with dairy ecosystem sources (e.g., Grana or Provolone cheese). Our data contribute to the description of microbial heterogeneity in L. helveticus and provide a more solid basis for understanding the functional and ecological significance of the presence of different L. helveticus biotypes in natural dairy starter cultures.

Pyroglutamic acid in cheese: presence, origin, and correlation with ripening time of Grana Padano cheese

Pyroglutamic acid is present in many cheese varieties and particularly in high amounts (0.5 g/100 g of cheese) in extensively ripened Italian cheeses (Grana Padano and Parmigiano Reggiano) that are produced with thermophilic lactic acid bacteria as starters. The mechanism of pyroglutamic acid formation in cheese seems to be mostly enzymatic, as demonstrated by the presence of only L-pyroglutamic acid enantiomer. Thermophilic lactobacilli are involved in pyroglutamic acid production, as suggested by the low pyroglutamic acid content found in Bagos, a ripened Italian mountain cheese produced without addition of starter. Because milk pasteurization did not influence the pyroglutamic acid content in the ripened Grana Padano cheese, the formation of pyroglutamic acid mainly depends on the whey starter microflora rather than that of raw milk. Pyroglutamic acid concentration is linearly correlated (R2 = 0.94) with the age of Grana Padano cheese.

Genetic and molecular analysis of wings apart-like (wapl), a gene controlling heterochromatin organization in Drosophila melanogaster

Mutations in the X-linked gene wings apart-like (wapl) result in late larval lethality associated with an unusual chromosome morphology. In brain cell metaphases of wapl mutants, sister chromatids of all chromosomes are aligned parallel to each other instead of assuming the typical morphology observed in wild type. This effect is due to a loosening of the adhesion between sister chromatids in the heterochromatic regions of the chromosomes. Despite this aberrant chromosome morphology, mutant brains exhibit normal mitotic parameters, suggesting that heterochromatin cohesion is not essential for proper centromere function. On the basis of these observations, we examined the role of wapl in meiotic chromosome segregation in females. wapl exhibits a clear dominant effect on achiasmate segregation, giving further support to the hypothesis that proximal heterochromatin is involved in chromosome pairing during female meiosis. We also examined whether wapl modulates position-effect variegation (PEV). Our analyses showed that wapl is a dominant suppressor of both white and Stubble variegation, while it is a weak enhancer of brown variegation. wapl maps to region 2D of the X chromosome between Pgd and pn. We identified the wapl gene within a previously conducted chromosomal walk in this region. The wapl transcriptional unit gives rise to two alternatively spliced transcripts 6.5- and 5-kb long. The protein encoded by the larger of these transcripts appears to be conserved among higher eukaryotes and contains a tract of acidic amino acids reminiscent of many chromatin-associated proteins, including two [HP1 and SU(VAR)3-7] encoded by other genes that act as suppressors of PEV.

Isolation of Mobiluncus species from the human vagina

We report the results of a study concerning the characteristics of 52 strains of Mobiluncus spp. isolated from 982 vaginal secretions from patients with suspected bacterial vaginosis. 158 of these women presented the features of this bacterial infection. Of the strains isolated, 39 belonged to the species Mobiluncus curtisii, (25 of these which to M. curtisii subsp. curtisii and 14, to M. curtisii subsp. holmesii), and 13, to Mobiluncus mulieris. The vaginal isolates of Mobiluncus spp. were identified by comparing their biochemical profiles with those of the type strains M. curtisii subsp. holmesii (ATCC 35,242), M. curtisii subsp. curtisii (ATCC 35,241) and M. mulieris (ATCC 35,243). All strains of M. mulieris proved to be sensitive to the antimicrobial agents assayed, while strains of M. curtisii were seen to be resistant only to metronidazole.

[Prognostic factors in the treatment of advanced cervical cancer. A retrospective study]

BACKGROUND

The value of prognostic factors in patients with advanced cervix carcinoma treated by radiotherapy was assessed in a retrospective study.

METHODS

From January 1977 through December 1990, 261 patients (average age 60 years) were treated at the Radiotherapy Department of the University of Turin. Distribution by stage was: 142 T2b (54%), 8 T3a (3%), 98 T3b (38%) and 13 T4 (5%). 83% of the patients underwent radiotherapy alone; the total dose was 45-88 Gy in 91 patients (42%) with poor clinical conditions, 60-75 Gy in 121 (56%) and 75-80 Gy in 5 cases. 17% of the patients was treated by surgery combined with radiotherapy. The median follow-up was 50 months (minimum 2, maximum 177 months).

RESULTS

The 5-year NED survival and local control were 42% (52% for T2b, 33% for T3 and 15% for T4). The severe (G3-G4) complication rate was very low (1.9%).

CONCLUSION

In our series, the prognostic factors which significantly influenced survival in the uni-variate analysis were: advanced T stage, contemporary infiltration of parametrium and vagina, nodal status, non squamous neoplasm, younger age and the absence of brachytherapy in the radiotherapy alone protocol.

Aorto-iliac steal syndrome. A rare case of renal hypoperfusion

In aorto-iliac occlusive disease a diversion of blood flow from visceral arteries to lower limbs rarely occurs. This condition is known as aorto-iliac steal syndrome. This report is about the case of a male patient affected by chronic atherosclerotic occlusion of the aorta associated with an aorto-iliac steal supported by an anomalous vessel coming from the left renal artery to the homolateral external iliac artery to the detriment of the renal blood flow. Renal sequential scintiscan (RSS) at rest and after stress test was employed to assess renal blood flow and excretory functions before and after an aorto-bifemoral bypass. Surgical revascularization permitted reversal of the steal phenomenon and the improvement of left renal blood flow.

[Clinical characteristics, familial distribution and preliminary genetic data in 9 different families with "Brugada's syndrome"]

Clinical electrocardiographic evaluation and complete non-invasive assessment including nuclear magnetic resonance (NMR) are reported for 7 subjects with cardiac arrest (CA), 6 due to ventricular fibrillation (VF) and 1 to ventricular tachycardia (VT). Two more subjects, one with and one without a family history of non-resuscitated sudden death (NRSD), were included. All 9 subjects showed the typical pattern of the Brugada's syndrome (BS), characterized by incomplete right bundle branch block, ST T elevation in V1 V3. We globally evaluated 64 subjects belonging to the 9 families examined, 5 of whom were identified in Bologna, 3 in Florence and one in Parma. BS is characterized in the experience described in the present paper by a family distribution of the ECG pattern in different members. Furthermore, a family distribution of NRSD, even at a young age, was observed. Electrocardiographic features were consistent with variable degrees and aspects of the intraventricular conduction delay (ICD) and of the ST T elevation pattern. NMR has been performed so far in 23 out of 64 members examined by echo, and was normal in 17/23, with only 6 showing pathological aspects such as mild dilatation of the right ventricle, reduced thickness of the right free wall, isolated dilatation of the right ventricular infundibulum and other minor pathological aspects. Preliminary genetic screening (GS), performed on 20 members of three families, was negative for the typical genetic patterns of right ventricular dysplasia (ARVD). In six families, GS is still ongoing. Genetic screening of sodium channel pathology is in progress in the same families. In conclusion, BS has been documented in the present paper as a hereditary syndrome, both for clinical and ECG aspects, associated with CA due to VF, which required an AICD implantation, at least in symptomatic subjects. There may exist a CONGENITAL form of BS due to pathology of sodium channels, without a demonstrable structural heart disease and an ACQUIRED form of BS secondary to an initial ARVD. From the clinical point of view, a complete evaluation, including serial ECG, pharmacological testing and programmed electrical stimulation of other subjects in the families, may be important in preventing sudden death, mainly in symptomatic subjects who always require an implantable cardioverter defibrillator.

HCV genotyping by three methods: analysis of discordant results based on sequencing

BACKGROUND

Correct genotyping of hepatitis C virus (HCV) RNA-positive serum samples may have important clinical and therapeutic implications.

OBJECTIVES

Three methods were compared to improve accuracy of HCV genotyping.

STUDY DESIGN

A panel of 144 HCV RNA-positive sera prospectively tested by a modified Okamoto's type-specific reverse transcription-nested polymerase chain reaction (RT-nPCR) (Okamoto H, Tokita H, Sakamoto M, Kojima M, Iizuka H, Mishiro S. J Gen Virol 1993; 74: 2385-2390) was retrospectively analyzed by two recently described methods which were reported to identify all HCV types and the majority of HCV subtypes: (i) a restriction fragment length polymorphism (RFLP) analysis of PCR products amplified from the 5' untranslated region (5'UTR) of the viral genome (Pohjanpelto P, Lappalainen M, Widell A, Asikainen K, Paunio M. Clin Diagn Virol 1996; 7: 7-16); and (ii) a type-specific RT-nPCR relevant to the core region (Ohno T, Mizokami M, Wu R, Saleh M, Ohba K, Orito E, Mukaide M, Williams R, Lau J. J Clin Microbiol 1997; 35: 201-207). The panel (according to results given by the modified Okamoto's method) consisted of: (i) 105 sera belonging to five different HCV subtypes; (ii) 20 specimens containing a mixture of > or = 2 genotypes; and (iii) 19 untypeable clinical samples.

RESULTS

There was agreement of the three methods for 78/144 (54.2%) blood samples, whereas discordant results were obtained for the remaining 66 samples, 56 of which could be typed by sequencing. Of these, 51 (91.7%) were correctly typed by RFLP, 37 (66.0%) by Ohno's and 27 (48.2%) by the modified Okamoto's procedure. The overall genotyping sensitivity of each method over the total number of 134 samples whose genotype was ascertained, was 96.2% for RFLP, 85.8% for Ohno's and 78.3% for the modified Okamoto's procedure.

CONCLUSIONS

RFLP analysis, notwithstanding some limitations in subtyping efficiency of genotype 1 samples, appears superior to the two RT-nPCR methods because: (i) it is able to type a larger number of samples; (ii) it is more efficient in identifying genotypes 2a/c, which are widespread in Italy; (iii) it is highly sensitive (together with Ohno's method) in recognizing genotypes 3 and 4.

The role of anillin in meiotic cytokinesis of Drosophila males

Anillin is a 190 kDa actin-binding protein that concentrates in the leading edges of furrow canals during Drosophila cellularization and in the cleavage furrow of both somatic and meiotic cells. We analyzed anillin behavior during D. melanogaster spermatogenesis, and focused on the relationships between this protein and the F-actin enriched structures. In meiotic anaphases anillin concentrates in a narrow band around the cell equator. Cytological analysis of wild-type meiosis and examination of mutants defective in contractile ring assembly (chickadee and KLP3A), revealed that the formation of the anillin cortical band occurs before, and does not require the assembly of the F-actin based contractile ring. However, once the acto-myosin ring is assembled, the anillin band precisely colocalizes with this cytokinetic structure, accompanying its contraction throughout anaphase and telophase. In chickadee and KLP3A mutant ana-telophases the cortical anillin band fails to constrict, indicating that its contraction is normally driven by the cytokinetic ring. These findings, coupled with the analysis of anillin behavior in twinstar mutants, suggested a model on the role of anillin during cytokinesis. During anaphase anillin would concentrate in the cleavage furrow before the assembly of the contractile ring, binding the equatorial cortex, perhaps through its carboxy-terminal pleckstrin homology (PH) domain. Anillin would then interact with the actin filaments of the acto-myosin ring through its actin-binding domain, anchoring the contractile ring to the plasma membrane throughout cytokinesis.

[Esophageal motility in systemic sclerosis and primary Raynaud' phenomenon by esophageal scintigraphy with semisolid meal]

BACKGROUND

Esophageal transit scintigraphy seems to be a valid methodology to assess impaired esophageal motility, also in the early stages of disease.

AIM

To discriminate patients with primary Raynaud's phenomenon (RPh and patients with systemic sclerosis (SSc) from healthy subjects, by esophageal scintigraphy with a semisolid meal.

METHODS

Thirty-two patients with primary RPh, 18 patients with SSc and 13 healthy subjects have been studied. Symptoms as dysphagia, acid regurgitation and heartburn, were scored. After an overnight fast, all subjects underwent esophageal scintigraphy, using a semisolid orally ingested bolus (10 ml apple purèe) labelled with 99mTc-sulfur colloid. Esophageal transit and emptying time and integral value were evaluated with the subjects in the upright (sitting) and in the supine position. Transit time was defined as the time from entry of 50% of radioactivity into the upper esophagus, up to the clearance of 50% of the bolus from the whole esophagus. Emptying time was defined as the time from the entry of 50% of radioactivity into the upper esophagus, up to the clearance of 100% of the bolus from the whole esophagus. Integral value was defined as the total count under the time/activity curve normalized to the maximum.

RESULTS

Esophageal transit and emptying time, and integral value, evaluated in both positions, were significantly higher in patients with SSc than in healthy subjects and than in patients with RPh. Moreover, patients with RPh had all three parameters, assessed in supine position, significantly longer compared to healthy subjects. Clinical scores regarding dysphagia, acid regurgitation and heartburn were not significantly different between patients with RPh and SSc.

CONCLUSIONS

Esophageal transit and emptying time and integral value seem to be able to discriminate well patients with primary RPh from patients with SSc and patients wih RPh from healthy subjects, suggesting an early mild esophageal dysfunction in RPh.

Presence of peptidase activities in different varieties of cheese

Lactic acid bacteria (LAB) counts, PepX activity towards H-Phe-Pro-beta NA, and aminopeptidase activity towards H-Arg-beta NA. HCl, H-Lys-beta NA, H-Leu-beta NA, H-Pro-beta NA, H-Glu-beta NA derivatives have been evaluated in 32 commercial samples of cheese, one processed cheese, and one yoghurt. The presence of intracellular exo-peptidase activities in cheese extracts free from bacterial cells was detected, even after 1 year of ripening. An inverse ratio between the presence of viable lactic microflora and peptidase activity in the cheese extracts was observed. The importance of LAB starter exo-peptidases in the degradation of casein oligopeptides, and the key role of autolysis in the release of peptidases in the cheese, are discussed.

Coinfection of the immunocompromised but not the immunocompetent host by multiple human cytomegalovirus strains

Coinfection by multiple human cytomegalovirus (HCMV) strains was investigated in immunocompetent individuals and AIDS patients. Thirty HCMV maternal and fetal or newborn isolate pairs from 9 cases of congenital HCMV infection as well as 36 HCMV isolates and 2 PCR-HCMV-positive CSF samples from 13 AIDS patients were tested by restriction fragment length polymorphism analysis of multiple genome regions. Results from the group of congenital infections showed that: i) all the 9 women with primary HCMV infection presumably harboured a single HCMV strain; ii) all strains were genetically unrelated; iii) isolates from infected fetuses or newborns consisted of a single strain apparently indistinguishable from the maternal strain; iv) no strain variations were observed in isolates from different body sites or in sequential isolates from newborns up to 8 months after birth. Results from the AIDS patient group demonstrated that; i) all patients were infected by unrelated strains; ii) 6/13 (46.1%) patients were coinfected by 2 or more HCMV strains; iii) in a single patient two different HCMV strains were detected in blood and urine, respectively, whereas a mixture of the two was found in the pharynx; iv) 4 patients showed the sequential appearance of a mixed virus population or different strains suggesting sequential reinfections.

Rapid detection of enteroviral RNA in cerebrospinal fluid (CSF) from patients with aseptic meningitis by reverse transcription-nested polymerase chain reaction

The aim of this study was to compare conventional enterovirus isolation with rapid detection of enteroviral RNA by a reverse transcription-nested polymerase chain reaction (RT-nPCR) method amplifying the 5' nontranslated region of the enteroviral genome in specimens from patients with aseptic meningitis. Reference enterovirus strains and clinical enterovirus isolates were analyzed to evaluate assay sensitivity and specificity. All known enteroviral serotypes tested, but one (echovirus type 22), were detected by RT-nPCR. A series of unrelated viral isolates as well as CSF samples from patients with meningitis/encephalitis or neurological syndromes unrelated to enterovirus infection were included as controls. A total of 47 specimens (31 CSF, 12 rectal swabs, 4 throat swabs) from 30 patients with aseptic meningitis were available for the study. Of the 31 CSF samples tested from 30 patients, 17 from 17 patients (54.8%) were positive by RT-nPCR, while only 10 from 10 patients (32.2%) were positive by culture. Thus, RT-nPCR allowed diagnosis of enterovirus meningitis in 7 additional patients compared to cell culture. The cytopathic effect was observed 5-15 days after inoculation of CSF specimens onto cell cultures, while direct detection of viral RNA in CSF samples by RT-nPCR permitted diagnosis of enteroviral meningitis within 1-2 days. On the whole, viral isolation was positive in 12/47 (25.5%) specimens, whereas viral RNA was detected by RT-nPCR in 11 additional samples (23/47, 48.9%). Specimens of the control group were consistently negative by both viral isolation and RT-nPCR. Restriction endonuclease analysis of PCR products (RFLP) was applied to differentiate poliovirus (PV) from non-polio enteroviruses (NPEV). All enterovirus strains detected in clinical samples (n = 23) were identified as NPEV by RFLP. Clinical isolates were typed by neutralization as echovirus type 30 (n = 6), while 6 were not typed. In conclusion, detection of enteroviral RNA in CSF by RT-nPCR allows: i) rapid diagnosis of enteroviral meningitis; ii) increased sensitivity with respect to virus isolation; iii) differentiation between PV and NPEV infections of the central nervous system.

Spindle self-organization and cytokinesis during male meiosis in asterless mutants of Drosophila melanogaster

While Drosophila female meiosis is anastral, both meiotic divisions in Drosophila males exhibit prominent asters. We have identified a gene we call asterless (asl) that is required for aster formation during male meiosis. Ultrastructural analysis showed that asl mutants have morphologically normal centrioles. However, immunostaining with antibodies directed either to gamma tubulin or centrosomin revealed that these proteins do not accumulate in the centrosomes, as occurs in wild-type. Thus, asl appears to specify a function required for the assembly of centrosomal material around the centrioles. Despite the absence of asters, meiotic cells of asl mutants manage to develop an anastral spindle. Microtubules grow from multiple sites around the chromosomes, and then focus into a peculiar bipolar spindle that mediates chromosome segregation, although in a highly irregular way. Surprisingly, asl spermatocytes eventually form a morphologically normal ana-telophase central spindle that has full ability to stimulate cytokinesis. These findings challenge the classical view on central spindle assembly, arguing for a self-organization of this structure from either preexisting or newly formed microtubules. In addition, these findings strongly suggest that the asters are not required for signaling cytokinesis.

A community-based outbreak of Salmonella enterica serotype Typhimurium associated with salami consumption in Northern Italy

An outbreak of Salmonella enterica serotype Typhimurium belonging to phage type (PT) 193 occurred in autumn 1995 and involved 83 individuals in a large area of Northern Italy (Lombardy Region). Epidemiological and microbiological investigations of strains isolated from clinical and food specimens revealed that the vehicle was a batch of salami, produced on 4 September 1995 by a local firm. The outbreak was contained when the batch was withdrawn from sale. Insufficient ripening of the salami had allowed the salmonella to survive, emphasizing the need to define criteria for the ripening process of foods such as salami.

Cooperative interactions between the central spindle and the contractile ring during Drosophila cytokinesis

We analyzed male meiosis in mutants of the chickadee (chic) locus, a Drosophila melanogaster gene that encodes profilin, a low molecular weight actin-binding protein that modulates F-actin polymerization. These mutants are severely defective in meiotic cytokinesis. During ana-telophase of both meiotic divisions, they exhibit a central spindle less dense than wild type; certain chic allelic combinations cause almost complete disappearance of the central spindle. Moreover, chic mutant spermatocytes fail to form an actomyosin contractile ring. To further investigate the relationships between the central spindle and the contractile ring, we examined meiosis in the cytokinesis-defective mutants KLP3A and diaphanous and in testes treated with cytochalasin B. In all cases, we found that the central spindle and the contractile ring in meiotic ana-telophases were simultaneously absent. Together, these results suggest a cooperative interaction between elements of the actin-based contractile ring and the central spindle microtubules: When one of these structures is disrupted, the proper assembly of the other is also affected. In addition to effects on the central spindle and the cytokinetic apparatus, we observed another consequence of chic mutations: A large fraction of chic spermatocytes exhibit abnormal positioning and delayed migration of asters to the cell poles. A similar phenotype was seen in testes treated with cytochalasin B and has been noted previously in mutants at the twinstar locus, a gene that encodes a Drosophila member of the cofilin/ADF family of actin-severing proteins. These observations all indicate that proper actin assembly is necessary for centrosome separation and migration.

Cell-wall protein profiles of dairy thermophilic lactobacilli

SDS-PAGE fingerprinting of cell-wall proteins extracted from 119 strains belonging to different species of lactic acid bacteria have been compared. The method of extraction and electrophoretic separation utilized in this work was found to be a reliable and rapid way for characterizing thermophilic lactobacilli species and strains. A protein of approximately 50 kDa was found to be characteristic for all the Lact. helveticus strains, and two cell-wall proteins of about 20 and 30 kDa were typical of the species Lact. delbrueckii, but the discrimination between the subspecies lactis and bulgaricus was not possible by the electrophoretic technique used. The other thermophilic species studied in this work presented cell-wall protein patterns that permitted their differentiation from both Lact. helveticus and Lact. delbrueckii.

Characteristics of non-O1 Vibrio cholerae isolated from the effluents of a treatment plant

We report the results of a study concerning the characteristics of 19 Non-O1 Vibrio cholerae strains isolated from the incoming sewage and the effluents of the treatment plant in Bologna (Italy). These strains were compared to those of a strain of Vibrio cholerae biotype El Tor. The behaviour of the Non-O1 Vibrios was seen to be quite similar to those of the El Tor biotype in all aspects studied and antigenic correlations were found by means of immunoblotting and cytotoxin production on VERO cells. Since these bacterial strains may be pathogenic in humans, we believe it useful to describe some of their characteristics.

Local antimicrobial therapy of oral mucositis in paediatric patients undergoing bone marrow transplantation

The present investigation has examined the clinical benefits of tobramycin, polymyxin E and amphotericin therapy in the management of oral mucositis in children undergoing chemotherapy prior to bone marrow transplantation. Tobramycin, polymyxin E, and amphotericin reduced the degree of oral mucositis more than conventional therapy of diphenhydramine, Maalox, and local analgesic. While there was a statistically significant fall in the severity of the mucositis with tobramycin, polymyxin E and amphotericin, this was unlikely to be of practical benefit.

Primary unusual cutaneous cryptococcosis in an HIV former drug-abuser patient

We describe an HIV-positive patient suffering from cutaneous cryptococcosis who was a former intravenous drug abuser and who presented a nodulo-ulcerated lesion on the back of his left hand. This was caused 4 months previously when the patient was injured by a pigeon nesting in an abandoned house. After fluconazole treatment for 4 months, no other visceral infections were recorded 18 months after complete healing of the lesion.

Extracranial carotid artery aneurysms

BACKGROUND

Extracranial carotid aneurysms are quite rare diseases. Their importance is linked both to critical localization and natural history which can lead to neurological events such as TIA and stroke. The importance of an accurate diagnosis is related to the necessity to carry out an early repair of these lesions and so to achieve the prevention of serious complications with minimal surgical risk.

MATERIALS AND METHODS

At the Department of Vascular Surgery of the University of Florence from January 1982 to December 1995, 2138 surgical procedures on extracranial carotid arteries carried out. Twenty-one (0.98%) were performed for aneurysms. On the basis of clinical history and instrumental findings we divided the patients into three groups: atherosclerotic aneurysms (AA, 10 cases), dysplasic aneurysms (DA, 6 cases) and pseudoaneurysms (PA, 5 cases).

RESULTS

Global mortality and major morbility rate was 4.7% (one patient suffered perioperative stroke). Eighteen (85.7%) were followed by echo color Doppler. No one stenosis and/or dilatation of operated vessel was observed during the mean follow-up period of 24 months. In one case (5.5%) of pseudoaneurysms group an asymptomatic internal carotid artery occlusion was discovered 3 months after surgery.

CONCLUSIONS

In our experience, surgical treatment of extracranial carotid aneurysms is associated with satisfactory results and low incidence of perioperative complications that justified an extensive and early surgical therapy.

Comparative quantification of human cytomegalovirus DNA in blood of immunocompromised patients by PCR and Murex Hybrid Capture System

BACKGROUND

Monitoring of human cytomegalovirus (HCMV) load by quantification of antigenemia, viremia and DNAemia is helpful in the management of HCMV infections in immunocompromised patients. In fact, threshold values of these viral parameters are associated with the emergence of clinical symptoms. In addition, the response to antiviral treatment is revealed by a decrease in viral load or virus disappearance from blood.

OBJECTIVES

Aim of this study was to compare HCMV DNA quantification in blood of immunocompromised patients by an 'in house' developed quantitative PCR (Q-PCR) assay and the commercially available Murex Hybrid Capture System (HCS).

STUDY DESIGN

HCMV DNA was quantified in 95 blood samples from 12 heart and heart-lung transplant recipients and 27 AIDS patients using both techniques. For HCS analysis 3.5 ml whole blood were utilized, whereas Q-PCR was performed using 1 x 10(5) peripheral blood leukocytes (PBL). HCMV DNA levels obtained by HCS and Q-PCR were expressed as number of genome equivalents (GE)/ml whole blood or 1 x 10(5) PBL, respectively. Results from HCS and Q-PCR were compared and submitted to statistical analysis. In addition, HCMV DNA values were compared to levels of antigenemia and viremia.

RESULTS AND CONCLUSIONS

Sensitivity of HCS, antigenemia and viremia with respect to Q-PCR were 37.2, 79.5 and 33.3%, respectively. Specificity was 100% for all techniques. On average, samples positive by Q-PCR only, contained low amounts of HCMV DNA. In particular, 45 (91.8%) out of 49 samples negative by HCS and positive by Q-PCR showed < 500 GE/1 x 10(5) PBL. A significant correlation was found between quantitative DNA levels in samples positive by both HCS and Q-PCR (n = 29, R = 0.693, P < 0.01). HCS positivity was associated to significantly higher DNA values as determined by Q-PCR as well as to significantly higher antigenemia and viremia levels. A decrease in DNAemia levels was observed using both HCS and Q-PCR after antiviral treatment. Given that the great majority of blood samples missed by HCS contain low levels of HCMV DNA which are not clinically significant, HCS seems very promising as an alternative to HCMV DNA quantification by PCR in solid organ transplant recipients and AIDS patients.

Antigenic profiles for the differentiation of Mobiluncus curtisii and Mobiluncus mulieris by immunoblotting technique

The antigenic profile of 30 vaginal isolates of Mobiluncus strains (22 M. curtisii and 8 M. mulieris) was determined by immunoblotting technique using mouse immune ascitic fluids containing polyclonal antibodies against the type strains M. curtisii subsp. holmesii (ATCC 35242) and M. mulieris (ATCC 35243). Two antigenic profiles were identified within M. curtisii isolates, whereas a certain variability was observed among M. mulieris strains where at least three antigens were constantly recognized. The detection of antigenic profiles of Mobiluncus strains by immunoblotting technique provided a simple method to identify Mobiluncus isolates at the species level.

UbcD1, a Drosophila ubiquitin-conjugating enzyme required for proper telomere behavior

The end-to-end association of chromosomes through their telomeres has been observed in normal cells of certain organisms, as well as in senescent and tumor cells. The molecular mechanisms underlying this phenomenon are currently unknown. We show here that five independent mutant alleles in the Drosophila UbcD1 gene cause frequent telomere-telomere attachments during both mitosis and male meiosis that are not seen in wild type. These telomeric associations involve all the telomeres of the D. melanogaster chromosome complement, albeit with different frequencies. The pattern of telomeric associations observed in UbcD1 mutants suggests strongly that the interphase chromosomes of wild-type larval brain cells maintain a Rab1 orientation within the nucleus, with the telomeres and centromeres segregated to opposite sides of the nucleus. The UbcD1 gene encodes a class I ubiquitin-conjugating (E2) enzyme. This indicates that ubiquitin-mediated proteolysis is normally needed to ensure proper telomere behavior during Drosophila cell division. We therefore suggest that at least one of the targets of UbcD1 ubiquitination is a telomere-associated polypeptide that may help maintain proper chromosomal orientation during interphase.

Internal carotid pseudo-occlusion: early and late results

Internal carotid pseudo-occlusion (ICP) is a pathology of difficult diagnostic evaluation and treatment in the group of extracranial carotid diseases. The authors report the results of 24 ICP(S) surgically treated in the last five years. No perioperative death was reported. The neurological morbility rate was as low as 4% (1/24), which is quite a good results for this high-risk pathology. Clinical and instrumental follow-up was performed (at 1-3-6-12-24 months from surgery). Six early asymptomatic thromboses (25%) were observed, and the remaining patients showed patent vessels and no symptoms at all. In conclusion surgical treatment of ICP is often able to prevent cerebral ischaemia, and the high rate of early occlusion should not limit surgical indication.

Bipolar spindle attachments affect redistributions of ZW10, a Drosophila centromere/kinetochore component required for accurate chromosome segregation

Previous efforts have shown that mutations in the Drosophila ZW10 gene cause massive chromosome missegregation during mitotic divisions in several tissues. Here we demonstrate that mutations in ZW10 also disrupt chromosome behavior in male meiosis I and meiosis II, indicating that ZW10 function is common to both equational and reductional divisions. Divisions are apparently normal before anaphase onset, but ZW10 mutants exhibit lagging chromosomes and irregular chromosome segregation at anaphase. Chromosome missegregation during meiosis I of these mutants is not caused by precocious separation of sister chromatids, but rather the nondisjunction of homologs. ZW10 is first visible during prometaphase, where it localizes to the kinetochores of the bivalent chromosomes (during meiosis I) or to the sister kinetochores of dyads (during meiosis II). During metaphase of both divisions, ZW10 appears to move from the kinetochores and to spread toward the poles along what appear to be kinetochore microtubules. Redistributions of ZW10 at metaphase require bipolar attachments of individual chromosomes or paired bivalents to the spindle. At the onset of anaphase I or anaphase II, ZW10 rapidly relocalizes to the kinetochore regions of the separating chromosomes. In other mutant backgrounds in which chromosomes lag during anaphase, the presence or absence of ZW10 at a particular kinetochore predicts whether or not the chromosome moves appropriately to the spindle poles. We propose that ZW10 acts as part of, or immediately downstream of, a tension-sensing mechanism that regulates chromosome separation or movement at anaphase onset.

Successful immune response to a recombinant hepatitis B vaccine in young patients with insulin-dependent diabetes mellitus

The study aimed to evaluate the immune response to a recombinant hepatitis B vaccine in young patients with insulin-dependent diabetes mellitus (IDDM), in view of reports of reduced efficacy in adults with IDDM. Sixty-five young people with IDDM, age 4.5 to 27.5 and diabetes duration 0.3 to 19 years and 174 age- and sex-matched healthy subjects were injected with a recombinant hepatitis B vaccine at 0, 1 and 6 months intramuscularly in the deltoid region. Three (4.6%) IDDM patients and 2 (1.1%) controls were non-responders (HBsAb titre, < 2 IU l-1) and 1 control was a low responder (HBsAb titre = 10 IU l-1). Among the 3 non-responder IDDM subjects, 2 had other autoimmune disease. Median HBsAb titre was similar in responding patients (120 IU l-1 and controls (125 IU l-1). There were no significant correlations between antibody titre and age, diabetes duration, HbA1c or insulin requirement. No association was found between HBsAb titre and any HLA genotype or the presence of microangiopathy. IDDM does not adversely affect the immune response to a recombinant hepatitis B vaccine in children, adolescents, and young adults, who can thus expect to benefit from its use in situations of risk of contracting hepatitis.

Mutations in twinstar, a Drosophila gene encoding a cofilin/ADF homologue, result in defects in centrosome migration and cytokinesis

We describe the phenotypic and molecular characterization of twinstar (tsr), an essential gene in Drosophila melanogaster. Two P-element induced alleles of tsr (tsr1 and tsr2) result in late larval or pupal lethality. Cytological examination of actively dividing tissues in these mutants reveals defects in cytokinesis in both mitotic (larval neuroblast) and meiotic (larval testis) cells. In addition, mutant spermatocytes show defects in aster migration and separation during prophase/prometaphase of both meiotic divisions. We have cloned the gene affected by these mutations and shown that it codes for a 17-kD protein in the cofilin/ADF family of small actin severing proteins. A cDNA for this gene has previously been described by Edwards et al. (1994). Northern analysis shows that the tsr gene is expressed throughout development, and that the tsr1 and tsr2 alleles are hypomorphs that accumulate decreased levels of tsr mRNA. These findings prompted us to examine actin behavior during male meiosis to visualize the effects of decreased twinstar protein activity on actin dynamics in vivo. Strikingly, both mutants exhibit abnormal accumulations of F-actin. Large actin aggregates are seen in association with centrosomes in mature primary spermatocytes. Later, during ana/telophase of both meiotic divisions, aberrantly large and misshaped structures appear at the site of contractile ring formation and fail to disassemble at the end of telophase, in contrast with wild-type. We discuss these results in terms of possible roles of the actin-based cytoskeleton in centrosome movement and in cytokinesis.