Spastin regulates VAMP7-containing vesicles trafficking in cortical neurons.

Alteration of axonal transport has emerged as a common precipitating factor in several neurodegenerative disorders including Human Spastic Paraplegia (HSP). Mutations of the SPAST (SPG4) gene coding for the spastin protein account for 40% of all autosomal dominant uncomplicated HSP. By cleaving microtubules, spastin regulates several cellular processes depending on microtubule dynamics including intracellular membrane trafficking. Axonal transport is fundamental for the viability of motor neurons which often have very long axons and thus require efficient communication between the cell body and its periphery. Here we found that the anterograde velocity of VAMP7 vesicles, but not that of VAMP2, two vesicular-SNARE proteins implicated in neuronal development, is enhanced in SPG4-KO neurons. We showed that this effect is associated with a slight increase of the level of acetylated tubulin in SPG4-KO neurons and correlates with an enhanced activity of kinesin-1 motors. Interestingly, we demonstrated that an artificial increase of acetylated tubulin by drugs reproduces the effect of Spastin KO on VAMP7 axonal dynamics but also increased its retrograde velocity. Finally, we investigated the effect of microtubule targeting agents which rescue axonal swellings, on VAMP7 and microtubule dynamics. Our results suggest that microtubule stabilizing agents, such as taxol, may prevent the morphological defects observed in SPG4-KO neurons not simply by restoring the altered anterograde transport to basal levels but rather by increasing the retrograde velocity of axonal cargoes.

Selective modulation of subtype III IP3R by Akt regulates ER Ca²âº release and apoptosis.

Ca²âº transfer from endoplasmic reticulum (ER) to mitochondria can trigger apoptotic pathways by inducing release of mitochondrial pro-apoptotic factors. Three different types of inositol 1,4,5-trisphosphate receptor (IP3R) serve to discharge Ca²âº from ER, but possess some peculiarities, especially in apoptosis induction. The anti-apoptotic protein Akt can phosphorylate all IP3R isoforms and protect cells from apoptosis, reducing ER Ca²âº release. However, it has not been elucidated which IP3R subtypes mediate these effects. Here, we show that Akt activation in COS7 cells, which lack of IP3R I, strongly suppresses IP3-mediated Ca²âº release and apoptosis. Conversely, in SH-SY 5Y cells, which are type III-deficient, Akt is unable to modulate ER Ca²âº flux, losing its anti-apoptotic activity. In SH-SY 5Y-expressing subtype III, Akt recovers its protective function on cell death, by reduction of Ca²âº release. Moreover, regulating Ca²âº flux to mitochondria, Akt maintains the mitochondrial integrity and delays the trigger of apoptosis, in a type III-dependent mechanism. These results demonstrate a specific activity of Akt on IP3R III, leading to diminished Ca²âº transfer to mitochondria and protection from apoptosis, suggesting an additional level of cell death regulation mediated by Akt.

Inherited interstitial deletion of chromosomes 5p and 16q without apparent phenotypic effect: further confirmation.

We describe two families in which an inherited interstitial deletion is present without apparent associated phenotypic abnormalities. The first deletion was discovered in a 19-year-old male with a previously diagnosed peroxisomal disorder. High-resolution chromosome analysis was interpreted as 46,XY,del(5)(p14.1p14.3). The patient's phenotypically normal mother had the same interstitial deletion. Chromosome 5p14 deletion has been reported in a three-generation family without phenotypic anomalies. We hypothesize that the affected son's phenotype may be coincidental or represent unmasking of an autosomal recessive peroxisomal disorder in the deleted region. The second interstitial deletion was detected by amniocentesis for advanced maternal age. High-resolution chromosome analysis was interpreted as 46,XX,del(16)(q13q22). The same deletion was found in the healthy mother and a normal brother. The pregnancy was carried to term and resulted in the birth of a normal girl. We report these cases as further evidence that rare, unbalanced deletion of specific chromosomal regions may result in no phenotypic effect. Consequences may result from expression of an autosomal recessive disorder on the homologous chromosome. Identification of such deletions is especially important for prenatal diagnosis and genetic counselling.

Mutations in the Newcastle disease virus hemagglutinin-neuraminidase protein that interfere with its ability to interact with the homologous F protein in the promotion of fusion.

Recent evidence suggests that the attachment (HN) and fusion (F) glycoproteins of Newcastle disease virus interact at the cell surface in a virus-specific manner to promote syncytium formation. Consistent with the existence of such an interaction, we have shown that it is possible to coimmunoprecipitate (co-IP) the two proteins from the surface of transiently expressing cells using a monoclonal antibody to either protein. Further, we show that a point mutation in the globular domain of HN that abolishes its receptor recognition and neuraminidase (NA) and fusion activities also abolishes its ability to interact with F in the co-IP assay. The mechanism by which this mutation might interfere with the interaction between the two proteins is discussed in terms of the postulate that recognition by HN of cellular receptors triggers its interaction with F and the apparently conflicting evidence for an interaction between the two proteins in the endoplasmic reticulum. Also, characterization of a set of chimeric HN proteins, having short overlapping sequences from a heterologous HN protein in the F-specific domain in the protein stalk, reveals that a weakened interaction between HN and F is still sufficient to trigger fusion.

Valgus knee stress in lumbosacral myelomeningocele: a gait-analysis evaluation.

Twenty-five independent community-ambulating patients with lumbosacral-level myelomeningocele (N = 50 limbs) underwent gait analysis. The limbs of these patients were divided into two groups based on thigh-foot angle (TFA): Group I (n = 20) had marked external tibial torsion, TFA > or = 20 degrees, and group II had TFA between 10 and 20 degrees. Ten limbs were excluded because of neutral or internal alignment. Twenty normal limbs with TFA = 10 degrees served as controls. An abnormal internal varus knee stress during stance was identified in all group I limbs and 12 (70%) of 20 limbs group II limbs compared with controls, which demonstrated an internal valgus stress. This internal varus moment was greater in group I limbs than in the abnormal limbs in group II (p < 0.05). Knee flexion was the only other parameter found to correlate with this stress and only in group I limbs. We conclude that (a) in this patient group, increased external tibial torsion is likely to result in an abnormal internal varus knee stress; (b) TFA > 20 degrees appears significantly to increase this stress; and (c) knee flexion is an important related parameter, but only in limbs with TFA between 10 and 20 degrees. We believe that this abnormal stress may predispose the knee to late arthrosis and that derotational osteotomies to normalize the TFA may prove to have a favorable long-term effect.

[Endometriosis of the lower abdominal wall. Report of two cases secondary to cesarean section]. / Endometriosi della parete addominale inferiore. Descrizione di due casi secondari a taglio cesareo.

The paper describes two cases of cutaneous endometriosis in correspondence with the surgical scar following cesarean section. The cases formed part of a series of 500 abdominal operations performed during the period 1988-89, of which about 200 were cesarean sections, with a 1% frequency. In line with the hypothesis regarding the spread of endometrial tissue during surgery and with that concerning peritoneal metaplasia, the authors recommend paying special attention during the technical procedure of extracting the fetus, and performing an introflexed suture of the uterine incision and of the parietal peritoneum.

[Use of ofloxacin in 45 cases of infection of the lower urinary tract in women]. / Impiego di ofloxacina in 45 casi di infezioni del tratto urinario inferiore femminile.

Forty-five female patients affected by lower urinary tract infections without secondary complications were examined. Ofloxacin was administered in three different dosages in order to evaluate drug efficacy and tolerance: 600 mg/day for 3 days in 22 cases; 300 mg/day for 3 days in 22 cases; 600 mg/day for 5 days in 1 case. Adverse effects were insignificant; clinical remission was virtually complete and urine tests proved negative in 98% of cases. On the basis of these findings it is possible to state that Ofloxacin therapy is efficacious in lower urinary tract infections without secondary complications in women.

Borderline malignant serous tumors of the ovary maintained on extracellular matrix: evidence for clonal evolution and invasive potential.

Four cases of advanced stage (II or III) and one case of early stage (IC) borderline malignant serous cystadenocarcinomas of the ovary were maintained on culture dishes coated with an extracellular matrix (ECM) produced by bovine corneal endothelial cells. Cells harvested for chromosomal analysis after 2-3 days showed diploid or near-diploid modalities in all cases. Banded chromosome studies in two cases revealed nonrandom clonal abnormalities with trisomy 2, 7, and 12 in seven of 13 metaphases. No structural abnormalities were noted. These cytogenetic findings differ from those found in malignant serous tumors of the ovary. In addition, borderline tumor cells digested the ECM in all cases and formed a cribiform pattern within a few days of primary culture. This study suggests clonal progression from early to advanced stages of borderline malignant serous tumors; readily distinguishable from overtly malignant serous tumors of the ovary. Ability of tumor cells derived from both primary tumors and metastatic implants to digest the ECM implies the possibility that borderline serous tumors have invasive potential.

Ewing's sarcoma of the scapula with metastases to the lung and eye.

A small, round cell tumor of the left scapula was found in a 3-month-old female Caucasian child. The histology was consistent with Ewing's sarcoma. Subsequently, a solitary pulmonary metastasis was excised. Thirty-one months after diagnosis, the child presented with leukokoria and a solitary pleural metastasis. The histology of both was identical to that of the original scapular tumor. G-banded karyotypes of the pulmonary metastasis and the ocular tumor revealed the presence of a balanced translocation, 46,XX, t(11;22)(q24;q12), which supported the original diagnosis of Ewing's sarcoma.

Acute nonlymphocytic leukemia in a glue sniffer.

A 17-year-old white male with a past history of chronic inhalational abuse of plastic glue was referred to our institution for sore throat, cervical adenopathy, and an abnormal peripheral blood smear. A diagnosis of acute myelomonocytic leukemia was made and abnormalities in cytogenetic studies were demonstrated. Specific inquiry regarding this form of drug exposure should be pursued when searching for possible etiologies of malignant disease.

T-cell depletion of bone marrow does not inhibit in vitro hematopoiesis.

One approach to overcome the problem of histoincompatibility in bone marrow transplantation is to use T cell depleted marrow from a haploidentical donor in an attempt to ameliorate graft-versus-host disease. Since the T cell requirements for normal hematopoiesis are uncertain, experiments were performed to study the effects of E rosette-T cell depletion on in vitro growth of hematopoietic progenitor cells. Marrow mononuclear cells were cultured in a modified CFU-GEMM assay before and after T cell depletion. The number of 7 day granulocytic and erythrocytic colonies, and 14 day granulocytic, erythrocytic and mixed colonies were enumerated and expressed in terms of colonies per 10(5) non T cells plated. T cell depletion did not result in decreased proliferation of any of these progenitors save possibly for 14 day granulocytic colonies in one of four experiments. In two cases, T cell depletion resulted in increased growth of progenitor cells. Three of four patients transplanted with T cell depleted haploidentical marrow cells engrafted. It is concluded that E rosette depletion of T cells from marrow does not decrease the potential of these cells to establish hematopoiesis in vitro or in vivo.

Relationship of the growth of leukemic cells in vitro to the outcome of therapy for acute nonlymphocytic leukemia.

Bone marrow cells obtained from 166 patients with acute nonlymphocytic leukemia were cloned in vitro. The number and size of clones produced differed among patients and was unrelated to French-American-British type of leukemia, to patient age, to whether the patient was studied at the time of initial diagnosis or at relapse, or to the cytogenetic (normal or abnormal metaphases) or cell cycle characteristics of the leukemic bone marrow cells. The ability of leukemic cells to clone in vitro was associated with poor response to therapy in vivo, with the remission rate being inversely related to cloning efficiency of the leukemic cells, and with remission durations being inversely correlated with the size of the cluster/colonies formed in vitro. Only an occasional patient whose marrow cells produced clonal growth in vitro and in whom cytogenetic abnormalities were detected entered complete remission with conventional remission induction therapy. Measurement of the clonogenic potential in vitro of leukemic marrow cells together with their cytogenetic type may help to distinguish between patients who should and should not receive cytosine arabinoside/anthracycline antibiotic remission induction therapy and patients who do and do not require intensive remission consolidation chemotherapy.

Adverse effects of aneuploidy on the outcome of remission induction therapy for acute nonlymphocytic leukaemia: analysis of types of treatment failure.

Cytogenetic studies were carried out on bone marrow specimens obtained from 98 patients with acute nonlymphocytic leukaemia. Patients were treated with cytosine arabinoside and an anthracycline antibiotic. The remission rate for patients in whom only normal metaphases were detected (NN patients) was 69% while the remission rates were 50% and 40% respectively for patients in whom both normal and abnormal metaphases were seen (NA patients) and for those in whom only abnormal metaphases were noted (AA patients). Analysis of remission induction failure types suggests that the differences in outcome were related to a tendency for patients with aneuploid leukaemia to be more likely to have drug resistant disease and to the lesser ability of NA and AA patients to survive and receive a second course of therapy if the first course failed to induce a complete remission.

"Masked" philadelphia chromosome (Ph1) due to an unusual translocation.

The case of a 58-year-old white female with Philadelphia (Ph1)-positive chronic myelocytic leukemia (CML) and a "masked" Ph1 chromosome is described. The Ph1 was due to a translocation involving chromosomes #12 and #22, in which most of the long arm of #12 had been translocated to the deleted #22 (Ph1). The necessity of performing banding analysis in those cases of CML where a Ph1 is not readily apparent is stressed and the literature on"masked" Ph1 chromosomes is briefly summarized.

Benign prostatic hyperplasia in an XX man.

A sixty-nine-year-old white phenotypic male who was being investigated for a myeloproliferative disorder, was found to have an XX karyotype in all cells examined in bone marrow, lymphocytes, and skin fibroblast cultures. Despite essentially no testosterone in the plasma, he also suffered from severe prostatic hyperplasia, a finding not reported previously in patients with this genotype. While endocrine studies showed normal follicle-stimulating hormone, the luteinizing hormone level was twice the upper limit of normal and estrogens were in the normal female range. Except for complete absence of Leydig cells, testicular histology resembled that usually found in Klinefelter syndrome. The patient died of the combined effects of the myeloproliferative disease and urinary tract obstruction. The mechanism of occurrence of the sex chromosome anomaly as well as the cause and implication of the unusual finding of prostatic hyperplasia are discussed.

Non-disjunction of an unusual X chromosome.

Because of multiple abnormalities in her children, a young mother was investigated and shown to have a 47,XXX chromosome constitution. Additional C group chromosomes without visible centromeric constrictions were found in a number of cells from the peripheral blood, and using C and Q banding techniques these chromosomes were identified as X chromosomes. Analysis of the banding karyotypes of 300 cells revealed that the acentric X chromosomes had the ability to replicate and that this replication was associated with non-disjunction leading to aneuploid cells. Even though cultured skin cells did not have acentric or extra chromosomes in addition to the triple-X, examination of buccal mucosa cells for the presence of X-bodies suggested that the phenomenon of non-disjunction was present in the epithelial cells of the patient. In addition to the X without a visible centromeric constriction, either acentric D or E chromosomes were found. The data suggest that a functional defect in the cells per se is responsible for the appearance of the acentric chromosomes.