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Biomedical subjects

C Hardy

Publications and source records attributed to C Hardy.

At least 37 records · Page 2Linked to original sources
PubMed1995

Rabbit mitochondrial DNA diversity from prehistoric to modern times.

The mitochondrial genetic variability in European rabbit (Oryctolagus cuniculus) populations present in Europe and North Africa from 11,000 years ago to the present day has been analyzed using ancient DNA techniques. DNA was extracted from 90 rabbit bones found in 22 archaeological sites dated between the Mesolithic and recent times. Nucleotide sequences present in a variable 233-bp domain of the cytochrome b gene were compared to those present in modern-day rabbits. The results show that the structure of ancient populations of wild rabbit exhibited remarkable stability over time until the Middle Ages. At this time, a novel type of mtDNA molecule abruptly appears into most wild populations studied from France. This mtDNA type corresponds to that currently present in the domestic breeds of rabbit examined so far. The relative rapidity by which this mtDNA type established and its absence in all sites examined before 1,700 years ago lend support to the hypothesis that between 2,000 and 1,000 years ago, man may have favored the development, into all regions of France, of animals carrying this particular mtDNA molecule. The origin of such animals has still to be found: animals previously living outside of France or within France but in very restricted areas? This event was concomitant with the documented establishment of warrens after the tenth century A.D. in Europe.

Africa, Northern↗
PubMed1995

Chemotherapy with vincristine/ifosfamide/carboplatin/etoposide in small cell lung cancer.

Although chemotherapy is considered the cornerstone of treatment for small cell lung cancer (SCLC), the majority of SCLC patients relapse and die of their disease within 2 years of diagnosis. Until newer, more effective drugs are developed, both optimization of available chemotherapeutic regimens and the use of combined chemotherapy/radiotherapy will be required to improve the survival of SCLC patients. Combining ifosfamide, carboplatin, and etoposide, among the most active single agents against SCLC, into the ICE regimen was a logical move that has resulted in improved response and survival rates. In limited and extensive SCLC, respectively, ICE and ICE administered with vincristine (VICE) have achieved overall response rates of 79% to 94% and 77% to 100% and 2-year survival rates of 24% to 33% and 9% to 25%, respectively. Treatment-related toxicities, especially myelosuppression, have hindered efforts to accelerate the administration of ICE and VICE regimens and to incorporate them into combined-modality treatments. However, the use of hematologic support measures, including growth factors and peripheral blood progenitor cells, may pave the way for maximizing the effectiveness of these regimens.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Analysis of 133 meioses places the genes for nevoid basal cell carcinoma (Gorlin) syndrome and Fanconi anemia group C in a 2.6-cM interval and contributes to the fine map of 9q22.3.

Four disease genes (NBCCS, ESS1, XPAC, FACC) map to 9q22.3-q31. A fine map of this region was produced by linkage and haplotype analysis using 12 DNA markers. The gene for nevoid basal cell carcinoma syndrome (NBCCS, Gorlin) has an important role in congenital malformations and carcinogenesis. Phase-known recombinants in a study of 133 meioses place NBCCS between (D9S12/D9S151) and D9S176. Haplotype analysis in a two-generation family suggests that NBCCS lies in a smaller interval of 2.6 cM centromeric to D9S287. These flanking markers will be useful clinically for gene tracking. Recombinants also map FACC (Fanconi anemia, group C) to the same region, between (D9S196/D9S197) and D9S287. The recombination rate between (D9S12/D9S151) and D9S53 in males is 8.3% and 13.2% in females, giving a sex-specific male:female ratio of 1:1.6 and a sex-averaged map distance of 10.4 cM. No double recombinants were detected, in agreement with the apparently complete level of interference predicted from the male chiasmata map.

Basal Cell Nevus Syndrome↗
PubMed1994

Ancient DNA from Bronze Age bones of European rabbit (Oryctolagus cuniculus).

The European rabbit (Oryctolagus cuniculus) is now widely distributed throughout the world as a result of transportation by man. The original populations, however, were confined to southern France and Spain. In order to investigate the role of human intervention in determining the genetic diversity of rabbit populations, we are studying the origin of rabbits introduced onto a small Mediterranean island (Zembra) near Tunis over 1400 years ago, by examining ancient DNA extracted from rabbit bones found both on Zembra and on the European mainland. Ancient DNA was successfully extracted from rabbit bones found at two archaeological sites dated to at least the Early Bronze Age (more than 3500 years ago) in south-central France, and compared to that found in modern mainland and island populations using a small variable region of the cytochrome b gene. The results confirm that the Zembra Island population is descended from that present over 1400 years ago. The technical aspects of DNA extraction from bones and the implications of this type of research for determining the origin of introduced rabbit populations are discussed.

Animals↗
PubMed1994

Duplication of the 15q11-13 region in a patient with autism, epilepsy and ataxia.

Various developmental abnormalities can give rise to the clinical syndrome of autism, and some are due to chromosomal anomalies. One syndrome has been identified in which behavioural disorder is associated with the clinical features of epilepsy and ataxia, and with the chromosomal anomaly of an extra marker chromosome containing a duplication of 15q11-13. The authors report a boy with autism, epilepsy, ataxia and an interstitial duplication of 15q, in whom molecular analysis reveals duplication of the GABRA5 and GABRB3 genes on the maternally derived chromosome.

Ataxia↗
PubMed1993

Limb congestion and sympathoexcitation during exercise. Implications for congestive heart failure.

During static exercise, heart failure (HF) subjects activate the sympathetic nervous system differently than normal controls. HF causes metaboreceptor desensitization with either enhanced mechanoreceptor activity or central command. In this report, we examined whether increased muscle interstitial pressure, as seen in HF, augments other neural systems. We measured muscle sympathetic nerve activity (MSNA; peroneal nerve) in 10 normals during static exercise (40% maximal voluntary grip) and posthandgrip circulatory arrest (PHG-CA). This was repeated after venous congestion (VC; cuff inflation to 90 mmHg). VC increased forearm volume (plethysmography) by 4.7%. MSNA responses to exercise were greater after VC (150.5 +/- 41.8 vs. 317.3 +/- 69.9 arbitrary units; P < 0.01). However, MSNA responses during PHG-CA were not affected by VC, and 31P nuclear magnetic resonance (n = 5) demonstrated no effect of VC on pH or H2PO4-. Similar effects of VC on MSNA were noted after ischemic exercise (n = 7), excluding flow alterations as the explantation. VC probably sensitized mechanically sensitive afferents since MSNA during involuntary biceps contractions increased after VC (n = 6), and skin sympathetic nerve responses during handgrip, an index of central command, were not increased by VC (n = 6).

Adult↗
PubMed1992

Membrane-associated chondroitin sulfate proteoglycan and fibronectin mediate the binding of hemopoietic progenitor cells to stromal cells.

The initial step in hemopoiesis is the binding of progenitor cells to stroma. What mediates this binding at the molecular level is not entirely clear. We have previously reported that the cell line FDCP-1, a factor-dependent hemopoietic progenitor cell, actively synthesizes a membrane-associated chondroitin sulfate (CS) proteoglycan (MA-PG) which is unstable. After the binding of the progenitor cell to stromal, the stability of the MA-PG is enhanced, suggesting its involvement in the binding of progenitor cells to the stroma. Since stromal cells possess pericellular fibronectin (FN), we examined the possibility that binding to stromal cells may involve interactions between MA-PG of FDCP-1 on the one side and pericellular FN in stromal cells on the other side. To examine this hypothesis, we developed a cell adherence assay to measure the binding of FDCP-1 cells to a monolayer of stromal cells or to FN-coated dishes. Cell binding was inhibited by a monoclonal antibody against CS as well as by free CS and heparin, suggesting the involvement of MA-PG in the binding. Pretreatment of FDCP-1 cells with chondroitinase ABC, which selectively removes the CS portion of the MA-PG, also affects binding to the stromal cells. The binding was also inhibited by a pentapeptide (GRGDS) which competes with the cell-binding domain of FN as well as by a monoclonal antibody anti-FN. We conclude that interactions between MA-PG and a putative integrin-like molecule in FDCP-1 and the heparin and the cell binding domains in pericellular FN in the stromal cells contribute to the stabilization of progenitor-stromal cell binding which originally comes about by homing receptors of progenitor cells.

Amino Acid Sequence↗
PubMed1991

Nuclear magnetic resonance imaging of the palliative operation for hypoplastic left heart syndrome.

Electrocardiographic-gated nuclear magnetic resonance (NMR) imaging has been shown to be effective for the evaluation of congenital heart disease, particularly in supracardiac regions. This study evaluated the postoperative status after a stage I palliative operation (Norwood procedure) for hypoplastic left heart syndrome. The NMR images from three patients were compared with those of angiography and depicted all components of the reconstructed supracardiac and intracardiac anatomy after this operation. Nonobstructive anastomosis of the main pulmonary artery to the proximal aorta was clearly demonstrated in each patient. The caliber of the central or branch pulmonary artery, patency and caliber of the systemic to pulmonary artery shunt and the size of the atrial communication were also depicted in each patient and these findings corresponded with angiographic results. The results suggest that NMR imaging is effective for assessing the results of initial palliative surgery for hypoplastic left heart syndrome, which seems to be important for managing patients before subsequent definitive surgery.

Anastomosis, Surgical↗
PubMed1991

[Role of emergency subtotal colectomy in neoplastic obstructions of the left colon].

From 1984 to 1990, 60 patients underwent emergent surgery for a neoplastic obstruction of the left colon. We performed 19 colostomies without initial exeresis and 41 immediate tumoral resections. In the latter group, five subtotal colectomies (S.T.C.) were performed, including four with immediate mechanical anastomosis. Two patients had synchronous cancers and three had pre-perforating cecal lesions. Three patients had an associated general peritonitis. Three of the patients treated with STC died. These were these patients with general peritonitis, two of whom also had hepatic metastases. The data found in the literature on neoplastic obstructions of the left colon treated with STC with immediate anastomosis (227 cases are published) show an overall mortality rate of 8.4% with 24% morbidity, a complication of the anastomosis occurring in 4.5% of all cases.

Aged↗
PubMed1991

[Antropyloric lithiasic obstruction. A variant of Bouveret's syndrome].

We report about one case of cholecystoduodenal fistula complicated by antropyloric lithiasic obstruction, which was treated surgically with gastrotomy and extraction of the calculus, in an 82-year-old woman. This case represents an anatomic variant of Bouveret's syndrome, which is classically defined as a duodenal lithiasic obstruction. On the basis of this case, the authors discuss the diagnostic and possibly therapeutic merits of digestive endoscopy and define the main clinical, anatomical and evolutive characteristics of this unfrequent complication of biliary lithiasis.

Aged↗
PubMed1990

Evaluation of surgical procedures for cyanotic congenital heart disease by using MR imaging.

ECG-gated MR imaging has been shown to be effective for the diagnosis of congenital heart disease. In this study, we assessed its role in the postoperative evaluation of surgical procedures in patients with complex congenital heart disease. MR images of 26 patients with Rastelli (five), Fontan (three), Senning (three), Damus (one), Jatene (eight), Waterston (four), and Potts (two) procedures were evaluated retrospectively. The accuracy of MR imaging was compared with that of angiography in 20 patients. The surgical anastomoses were identified in all patients. Patency, atresia, or hypoplasia of central pulmonary arteries and postoperative complications (focal stenoses of pulmonary arteries, thrombosed conduit, peri-conduit abscess) were shown. Narrowing of the right ventricular outflow tract and focal compression of the proximal pulmonary arteries were recognized as specific complications of the Jatene procedure. MR imaging appears to be effective in the postoperative evaluation of surgical procedures used for congenital heart disease. It should be considered as an alternative to repeated catheterization and angiography for the postoperative examination of children with complex congenital heart disease.

Adolescent↗
PubMed1990

[Surgical treatment of infectious aneurysm of the popliteal artery. Description of a case caused by Campylobacter jejuni and a review of the literature].

The authors describe a case of mycotic aneurysm of the popliteal artery secondary to Campylobacter jejuni-derived infectious endocarditis treated by excision and in situ femoro tibial venous bypass, and take the opportunity to review 14 literature cases of infectious aneurysm of popliteal artery. This diagnosis is most frequently evoked by the development in an infectious setting of a throbbing inflammatory mass in the popliteal fossa. Management is aimed at controlling the infection and insuring proper distal vascularization. Eradication of the infection rests with the excision of the aneurysm and adequate antibiotherapy for at least 6 weeks. Distal vascularization is best provided (2 cases) by extra-anatomical bypass. However, in situ bypassing (9) is possible provided apyrexia and negative blood cultures have been obtained by preoperative antibiotherapy. The material used must be a venous autograft, whenever possible.

Adult↗
PubMed1990

Murine spleen culture: homing of hemopoietic progenitor cells to spleen is not mediated by a similar mechanism to that in marrow.

We have previously shown that in long-term bone marrow cultures (LTMC) the specific recognition and binding of hemopoietic stem cells to stroma, which we call "homing," is mediated by a recognition mechanism involving a surface membrane lectin with galactosyl and mannosyl specificities. Subsequent in vivo studies in lethally irradiated mice confirmed that homing to the marrow similarly involves a galactosyl- and mannosyl-specific recognition mechanism. However, these in vivo studies suggested that homing of hemopoietic progenitor cells to spleen was based upon a different molecular recognition mechanism. In the present study splenic homing was investigated in a cell culture system composed of an adherent layer of splenic stromal cells inoculated with stroma-free stem cells from the supernate of LTMC. In this system, splenic stroma supported proliferation and differentiation of hemopoietic precursors for a few weeks. When stem cells were added to the cultures in the presence or absence of inhibitory concentrations of neoglycoprotein reagents specific for galactosyl, mannosyl, or fucosyl lectins, the pattern of production of total cells, pluripotential stem cells (CFU-S), and granulocyte-macrophage committed progenitors (CFU-GM) remained the same. These data support our in vivo observations that homing of stem cells to splenic stroma is not mediated by a surface lectin with galactosyl and mannosyl specificities as it is in bone marrow, but rather by a different molecular mechanism.

Animals↗
PubMed1990

Interaction of late murine erythroid progenitors and stroma involves a recognition mechanism with fucosyl specificity.

We have previously reported that the specific recognition and binding of murine hemopoietic progenitors spleen colony-forming units (CFU-S) and granulocyte-macrophage CFU (CFU-GM) to hemopoietic stroma is dependent upon a membrane recognition system with galactose and mannose specificities. By using synthetic neoglycoproteins with galactose, mannose, or fucose covalently bound to bovine serum albumin (BSA) in standard long-term bone marrow cultures (LTBMC), galactosyl-BSA (gal-BSA) and mannosyl-BSA (man-BSA) but not fucosyl-BSA (fuc-BSA) inhibited the binding of CFU-S and CFU-GM to the stromal layer. In the present work it was shown that binding of erythroid burst-forming units (BFU-E) to stroma in standard LTBMC is also inhibited by gal-BSA and man-BSA. We then studied a different system of LTBMC that favored erythropoiesis and allowed the production of erythroid CFU (CFU-E) for 4 weeks. In the presence of the fuc-BSA as well as gal-BSA and man-BSA, total cell production and CFU-E production were halted in the supernate as well as the adherent layer. These results indicate the presence of a fucosyl recognition system on the surface of the late erythroid precursors, CFU-E.

Animals↗