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Biomedical subjects

S Gerber

Publications and source records attributed to S Gerber.

At least 19 recordsLinked to original sources
PubMed2003

Gene flow estimation with microsatellites in a Malagasy seed orchard of Eucalyptus grandis.

Eucalyptus grandis has a mixed-mating reproductive system. Malagasy Eucalyptus seed orchards were established 15 years ago with two aims both based on panmixia: open-pollinated seed production and genetic improvement. The panmixia hypothesis has never been confirmed in the seed orchard. From a seedling seed-orchard stand comprising 349 trees and using data obtained with six selected microsatellite markers, paternity analysis was performed for 724 offspring collected on 30 adult trees. Paternity assignment, based on exclusion procedures and likelihood-ratio method, was achieved with high accuracy; the exclusion probability value was 0.997. The outcrossing rate was very high (96.7%). More than 50% of potential male trees (199 out of 349) in the seed orchard contributed to pollination for 440 offspring of 30 progenies (8.6% of the basic population). The pollination rate from outside the seed orchard was high (39.2%), but might be due to the small size of this seed orchard. This study showed that "panmixia-like pollination" can be assumed.

Crosses, Genetic↗
PubMed2003

[Quantitative analysis of contrast enhanced MRI of the inferior alveolar nerve in inflammatory changes of the mandible].

PURPOSE: To evaluate the role of contrast enhanced MRI in quantifying signal changes of the inferior alveolar nerve following inflammatory changes of the mandible. MATERIAL AND METHODS: 30 patients with inflammatory changes of the mandible underwent MRI of the face. Both sides of the mandible, the affected as well as the unaffected healthy side were evaluated retrospectively. Regions of interest were placed at 5 defined places on both sides to assess signal intensity before and after intravenous application of paramagnetic contrast agent. The results of the measurements were compared between the healthy and the affected side (t-test, p < 0.05) and correlated with clinical findings (t-test, p < 0.05). RESULTS: All patients with hypesthesia of the inferior alveolar nerve in areas of the lips or chin (n = 4) showed a marked increase in signal intensity from 35 % to 83 % distal to the inflammatory process. Patients without sensitivity disorders showed less increase in signal intensity with a maximum of 51 % distal to the inflammatory process. In nearly all patients no contrast enhancement was observed distal to the first molar on the unaffected side. CONCLUSIONS: Quantitative analysis of contrast enhanced MRI of the neurovascular bundle is able to show pathologic mandibular lesions. In case of inflammatory changes of the mandible the neurovascular bundle is able to show pathologic mandibular lesions. In case of inflammatory changes of the mandible, the neurovascular bundle shows a significant increase in signal intensity distal to the lesion compared to the unaffected healthy side of the mandible.

Adolescent↗
PubMed2002

Pituitary carcinoma: report of an exceptional case and review of the literature.

Pituitary carcinomas are exceptional tumors and constitute 0.1 to 0.2% of pituitary tumors. Their definition includes well-established criteria but distant metastasis is the hallmark required for diagnosis. We report the fourth case of gonadotropic pituitary carcinoma described in the literature. This case illustrates the dramatic outcome of these tumors. The most interesting feature of our case was the loss of differentiation with time, established by retrospective analysis of the primary tumor surgically treated 15 years earlier. Most of the previously reported cases exhibited a majority of adrenocoticotropin and non-functioning pituitary tumors. However, the frequency of non-functioning tumors seems smaller than previously believed. In the discussion, we stress the need to detect these very aggressive tumors as early as possible and identify treatments to improve the dramatic course of these carcinomas.

Carcinoma↗
PubMed2002

[Creation of an educational CD-ROM using a PACS].

Presentation of MIRIAM 2: We describe the materials used for the creation of and the content of a CD-ROM entitled '77 neuroradiological case reports'. We mention the gathering of clinical and imaging data, exclusively provided by a PACS. Our work demonstrates that a CD-ROM is an appropriate interactive medium for radiological teaching. Its creation can be simplified thanks to a PACS, but it nonetheless remains work intensive.

Brain Diseases↗
PubMed2001

Potassium thiocyanate argentates: K3[Ag(SCN)4], K4[Ag2(SCN)6] and K[Ag(SCN)2] .

The anions of the title compounds contain [Ag(SCN)4] units, with the S atoms coordinating to Ag+ in a tetrahedral arrangement. Whereas in the isolated anions of tripotassium tetrathiocyanatoargentate(I), K3[Ag(SCN)4], (I), all SCN- groups are bonded as terminal ligands, in tetrapotassium di-mu-thiocyanato-S:S-bis[dithiocyanatoargentate(I)], K4[Ag2(SCN)6], (II), two AgS4 tetrahedra share one common edge. In poly[potassium [argentate(I)-di-mu-thiocyanato-S:S]], K[Ag(SCN)2], (III), edge- and vertex-sharing of AgS4 tetrahedra results in infinite [Ag(SCN)2]- layers.

Journal Article↗
PubMed2001

Results of intensive chemotherapy followed by hematopoietic stem-cell rescue in 22 patients with refractory or recurrent primary CNS lymphoma or intraocular lymphoma.

PURPOSE: To assess the feasibility and efficacy of intensive chemotherapy with hematopoietic stem-cell rescue (IC + HCR) in patients with refractory or recurrent primary CNS lymphoma (PCNSL) or intraocular lymphoma (IOL). PATIENTS AND METHODS: IC consisted of thiotepa 250 mg/m(2)/d days -9 through -7, busulfan 10 mg/kg (total dose) days -6 through -4, and cyclophosphamide 60 mg/kg/d days -3 and -2. Intravenous clonazepam 2 mg/d was given prophylactically from the day before initiation of busulfan therapy to the day after completion of busulfan therapy. Patients with refractory or recurrent PCNSL underwent IC + HCR only if they were chemosensitive to two cycles of salvage treatment with cytarabine (2 g/m(2)/d days 2 through 5 and 50 mg/m(2)/d days 1 through 5 in a 12-hour infusion) and etoposide (VP-16; 200 mg/m(2)/d days 2 through 5) (CYVE). Patients with IOL refractory to high-dose methotrexate (MTX) and cytarabine entered the IC + HCR program directly. RESULTS: Twenty-two patients (10 with relapses, 12 with refractory disease) were enrolled. Twenty patients entered the IC + HCR program: twelve entered after CYVE treatment, seven entered directly, and one had previously been retreated with high-dose MTX. Before IC, eight patients were in complete remission (CR), four were in partial remission (PR), one had stable disease, and seven had refractory disease. After IC + HCR, 16 patients entered CR, two remained in PR, one had stable disease, and one had disease progression. Fourteen patients remained alive (median follow-up time, 41.5 months). The overall probability of survival at 3 years was 63.7%. After IC, that probability was 60% and the 3-year probability of event-free survival was 53%. Seven patients had neurologic adverse events during the entire procedure. CONCLUSION: IC + HCR proved feasible and effective in patients with refractory or recurrent PCNSL or IOL. The entire procedure seemed to be most toxic in patients > or = 60 years. A prospective multicenter study is ongoing.

Adult↗
PubMed2001

Colposcopic evaluation after a repeat atypical squamous cells of undetermined significance (ASCUS) smear.

OBJECTIVES: Management of patients with atypical squamous cells of undetermined significance (ASCUS) remains controversial. We chose to repeat the Pap smear after four months. If ASCUS persisted in this second test, the patient was advised to undergo colposcopy. Our objective is to determine the clinical significance and the prediction of neoplasia among these patients through a colposcopic examination. METHODS: Of 29,827 patients who had a Pap smear, ASCUS were detected in 1387 (5%) and persisted in the repeat smear of 225 (16%). Colposcopy and an additional Pap smear were performed on 186 patients. RESULTS: Out of 186 colposcopic evaluations, 91 (49%) were normal and the patients had a negative Pap smear. Colposcopy was abnormal in 95/186 patients (51%) (Table 1). Histology of the directed biopsies revealed 38 (21%) low-grade squamous intraepithelial lesions (LSIL) and 17 (9%) high-grade squamous intraepithelial lesions (HSIL). Forty patients (21%) with normal biopsies had ASCUS for the third time in the Pap smear. CONCLUSIONS: Colposcopic evaluation after a repeated Pap smear with ASCUS is an appropriate cost-effective management. Finding 30% of LSIL or HSIL justifies this additional investigation.

Adolescent↗
PubMed2001

Complete exon-intron structure of the RPGR-interacting protein (RPGRIP1) gene allows the identification of mutations underlying Leber congenital amaurosis.

Leber congenital amaurosis (LCA) is a genetically heterogeneous autosomal recessive condition responsible for congenital blindness or greatly impaired vision since birth. So far, six LCA loci have been mapped but only 4 out of 6 genes have been identified. A genome-wide screen for homozygosity was conducted in seven consanguineous families unlinked to any of the six LCA loci. Evidence for homozygosity was found in two of these seven families at the 14q11 chromosomal region. Two retinal specific candidate genes were known to map to this region, namely the neural retina leucine zipper (NRL) and the retinitis pigmentosa GTPase regulator interacting protein (RPGRIP1). No mutation of the NRL gene was found in any of the two families. Thus, we determined the complete exon-intron structure of the RPGRIP1 gene. RPGRIP1 encompasses 24 coding exons, nine of which are first described here with their corresponding exon-intron boundaries. The screening of the gene in the two families consistent with linkage to chromosome 14q11 allowed the identification of a homozygous null mutation and a homozygous missense mutation, respectively. Further screening of LCA patients unlinked to any of the four already identified LCA genes (n=86) identified seven additional mutations in six of them. In total, eight distinct mutations (5 out of 8 truncating) in 8/93 patients were found. So far this gene accounts for eight out of 142 LCA cases in our series (5.6%).

Amino Acid Sequence↗
PubMed2001

Human papillomavirus virus-like particles are efficient oral immunogens when coadministered with Escherichia coli heat-labile enterotoxin mutant R192G or CpG DNA.

Certain human papillomaviruses (HPVs) cause most cervical cancer, which remains a significant source of morbidity and mortality among women worldwide. HPV recombinant virus-like particles (VLPs) are promising vaccine candidates for controlling anogenital HPV disease and are now being evaluated as a parenteral vaccine modality in human subjects. Vaccines formulated for injection generally are more costly, more difficult to administer, and less acceptable to recipients than are mucosally administered vaccines. Since oral delivery represents an attractive alternative to parenteral injection for large-scale human vaccination, the oral immunogenicity of HPV type 11 (HPV-11) VLPs in mice was previously investigated; it was found that a modest systemic neutralizing antibody response was induced (R. C. Rose, C. Lane, S. Wilson, J. A. Suzich, E. Rybicki, and A. L. Williamson, Vaccine 17:2129-2135, 1999). Here we examine whether VLPs of other genotypes may also be immunogenic when administered orally and whether mucosal adjuvants can be used to enhance VLP oral immunogenicity. We show that HPV-16 and HPV-18 VLPs are immunogenic when administered orally and that oral coadministration of these antigens with Escherichia coli heat-labile enterotoxin (LT) mutant R192G (LT R192G) or CpG DNA can significantly improve anti-VLP humoral responses in peripheral blood and in genital mucosal secretions. Our results also suggest that LT R192G may be superior to CpG DNA in this ability. These findings support the concept of oral immunization against anogenital HPV disease and suggest that clinical studies involving this approach may be warranted.

Adjuvants, Immunologic↗
PubMed2001

Interleukin-1 receptor antagonist gene polymorphism and circulating levels of human immunodeficiency virus type 1 RNA in Brazilian women.

Interleukin-1 receptor antagonist (IL-1ra) gene polymorphisms in 83 human immunodeficiency virus (HIV)-seropositive women were evaluated. Fourteen of the subjects (16.9%) were homozygous for IL-1ra allele 2 (IL-1RN*2). These women had a lower median level of HIV RNA than did women homozygous for allele 1 (IL-1RN*1) (P = 0.01) or heterozygous for both alleles (P = 0.04). Among 46 subjects not receiving antiretroviral treatment, HIV levels were also reduced in IL-1RN*2 homozygous individuals (P < 0.05). There was no relation between IL-1ra alleles and CD4 levels.

Female↗
PubMed2001

Lipopolysaccharide stimulation of 70 kilo Dalton heat shock protein messenger ribonucleic acid production in cultured human fetal membranes.

OBJECTIVE: The 70 kilo Dalton heat shock protein is up-regulated when cells are under physiological stress. It prevents protein denaturation and incorrect polypeptide assembly, and inhibits apoptosis as well as the transcription of genes coding for pro-inflammatory cytokines. To evaluate if up-regulation of heat shock protein 70 can occur during pregnancy, we examined whether addition of bacterial lipopolysaccharide to human amniochorion membranes in vitro stimulated heat shock protein 70 gene transcription. MATERIALS AND METHODS: Amniochorionic membranes (n = 5), collected at the time of elective repeat cesarean section prior to labor from normal term gestations, were placed in an organ explant system. After 48 hour in culture, the membranes were stimulated with lipopolysaccharide for 24 hours. Total RNA was extracted and subjected to an oligo dT primed reverse transcriptase reaction followed by polymerase chain reaction (PCR) using heat shock protein 70 specific primers. PCR products were hybridized with biotinylated internal probes and identified by enzyme-linked immunosorbent assay (ELISA). Results were analyzed by Mann-Whitney U test. A p < 0.05 was significant. RESULTS: Heat shock protein 70 messenger RNA was expressed by all fetal membrane preparations both prior to and following in vitro culture. Addition of lipopolysaccharide increased the concentrations of heat shock protein 70 messenger RNA in each sample tested from a mean of 35.5 +/- 29.6 ng/milliliter (12.1-80.1 ng/milliliter) to 169.6 +/- 69.9 ng/ml (51.7-218.2 ng/milliliter) (p = 0.03). CONCLUSION: Human fetal membranes constitutively express heat shock protein 70 messenger ribonucleic acid. Bacterial lipopolysaccharide markedly stimulated heat shock protein 70 messenger RNA gene transcription in human fetal membranes. Thus, heat shock protein 70 is inducible in fetal membranes and may facilitate fetal survival under adverse conditions.

Cesarean Section↗
PubMed2001

Complete abolition of the retinal-specific guanylyl cyclase (retGC-1) catalytic ability consistently leads to leber congenital amaurosis (LCA).

PURPOSE: Leber congenital amaurosis (LCA) is the earliest and the most severe form of all inherited retinal dystrophies. In 1996, the current investigators ascribed the disease in families linked to the LCA1 locus on chromosome 17p13.1 to mutations in the photoreceptor-specific guanylyl cyclase (retGC-1) gene. So far, 22 different mutations, of which 11 are missense mutations, have been identified in 25 unrelated families. This is a report of the functional analyses of nine of the missense mutations. METHODS: cDNA constructs were generated that contained the retGC-1 missense mutations identified in patients related to the LCA1 locus. Mutants were expressed in COS7 cells and assayed for their ability to hydrolyze guanosine triphosphate (GTP) into cyclic guanosine monophosphate (cGMP). RESULTS: All mutations lying in the catalytic domain showed a complete abolition of cyclase activity. In contrast, only one mutation lying in the extracellular domain also resulted in a severely reduced catalytic activity, whereas the others showed completely normal activity. CONCLUSIONS: More than half the mutations identified in patients related to the LCA1 locus are truncating mutations expected to result in a total abolition of retGC-1 activity. Concerning missense mutations, half of them lying in the catalytic domain of the protein also result in the complete inability of the mutant cyclases to hydrolyze GTP into cGMP in vitro. In contrast, missense mutations lying in the extracellular domain, except one affecting the initiation codon, showed normal catalytic activity of retGC-1. Nevertheless, considering that all patients related to the LCA1 locus displayed the same phenotype, it can be assumed that all missense mutations would have the same dramatic consequences on protein activity in vivo as truncation mutations.

Animals↗
PubMed2000

[Laparoscopic transabdominal preperitoneal hernioplasty. Evaluation of complications due to transabdominal approach].

INTRODUCTION: Since the introduction of laparoscopic hernioplasty the TAPP procedure (transabdominal preperitoneal approach) has become the most widely used technique. Many surgeons have changed to the total extraperitoneal approach (TEP), because they fear the consequences of a peritoneal lesion. METHOD: We evaluated our results with TAPP in a retrospective study, with special attention to complications caused by the approach. We operated on 460 hernias in 390 patients in a period of 5 years. RESULTS: Complication rates and recurrence rates were similar to those after TEP. There was a marked learning curve with decrease of both rates during the evaluated years. There were no complications related to the transabdominal approach other than trocar hernias, the rate of which could be reduced by eliminating the learning curve and by using smaller trocar diameter. CONCLUSION: We see no reason to change from TAPP to the TEP technique.

Adult↗
PubMed2000

[Paratesticular sarcomas. Case report of leiomyosarcoma].

Paratesticular sarcomas are rare. We discuss this entity with the aid of a case report and the existing literature. The therapy of these tumors includes resection and possible adjuvant radiotherapy. Rhabdomyosarcomas are an exception, because they also show a good response to chemotherapy.

Diagnosis, Differential↗
PubMed2000

The photoreceptor cell-specific nuclear receptor gene (PNR) accounts for retinitis pigmentosa in the Crypto-Jews from Portugal (Marranos), survivors from the Spanish Inquisition.

The last Crypto-Jews (Marranos) are the survivors of Spanish Jews who were persecuted in the late fifteenth century, escaped to Portugal and were forced to convert to save their lives. Isolated groups still exist in mountainous areas such as Belmonte in the Beira-Baixa province of Portugal. We report here the genetic study of a highly consanguineous endogamic population of Crypto-Jews of Belmonte affected with autosomal recessive retinitis pigmentosa (RP). A genome-wide search for homozygosity allowed us to localize the disease gene to chromosome 15q22-q24 (Zmax=2.95 at theta=0 at the D15S131 locus). Interestingly, the photoreceptor cell-specific nuclear receptor (PNR) gene, the expression of which is restricted to the outer nuclear layer of retinal photoreceptor cells, was found to map to the YAC contig encompassing the disease locus. A search for mutations allowed us to ascribe the RP of Crypto-Jews of Belmonte to a homozygous missense mutation in the PNR gene. Preliminary haplotype studies support the view that this mutation is relatively ancient but probably occurred after the population settled in Belmonte.

Chromosomes, Human, Pair 15↗
PubMed2000

The morcellator knife: a new laparoscopic instrument for supracervical hysterectomy and morcellation.

BACKGROUND: Cutting the cervix, morcellation, and extraction of the uterus and myomata remain major problems in endoscopic surgery. We developed an efficient, safe, reusable, and inexpensive instrument to cut the cervix and morcellate the uterus and myomata: the morcellator knife. INSTRUMENT: The morcellator knife is a classic lancet with an interchangeable blade, transformed into an endoscopic instrument that can be inserted easily through a 10-mm-diameter trocar. The blade has an automatic retraction system and is set in the standby position, ensuring security. Cutting the cervix and uterine or myoma fragmentation are easy. The mass to be cut is held between two grasping forceps for easy cutting with the blade, under permanent visual control. After morcellation, extraction of the masses is performed through a posterior culdotomy. EXPERIENCE: We have used this morcellator knife in 54 subtotal hysterectomies and 16 myomectomies. There were no complications during the procedures. Morcellation lasted 3-14 minutes and involved the use of an average of two to three blades. CONCLUSION: The morcellator knife is a simple, safe, reusable, and inexpensive instrument with a low maintenance cost.

Female↗