Biomedical subjects
Publications and source records attributed to L Martin.
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Sixty-eight subjects ranging in age from 6 to 23 years were studied in an 'auditory oddball' event-related potential (ERP) paradigm. Our results replicate other studies, finding P3 as the most consistent component of ERPs since childhood, although great variability of this component was found in the 6-year-old group. Separate age/ERP component latency and amplitude linear regressions were computed for subjects 6-14 and 6-23 years old. Our data show in both groups a significant negative and positive correlation between age and P3 latency and N1-P2 amplitude respectively. The age/P3 latency slope for the subjects under 15 years old was -19.00 msec/year versus 8.15 msec/year for all subjects (6-23 years old). Our results indicate that P3 latency during childhood decreases with age, reaching an asymptote after or during the second decade of life. No curvilinear relationship between age and P3 latency was found over the child groups, although a significant curvilinear relationship was found over the entire age range. This study showed no significant gender differences in latency at any age group. However, in the adult group females showed significantly larger amplitudes than males.
INTRODUCTION: Cutaneous hematomas are a cause of hospitalization in departments of dermatology. Their clinical diagnosis can be difficult, particularly since they can masquerade as thrombophlebitis or abscesses. We conducted a retrospective study so as to specify their frequency, clinical aspects and circumstances of occurrence. PATIENTS AND METHODS: The search for hospitalizations was conducted, using a computer data coding and key word "hematoma", from January 1997 to March 2003. The following items were studied: age, gender, clinical aspect on admission, topography, use of anti-platelets or anticoagulants, the existence of documented overdosing, treatment before hospitalization and existence of fever. RESULTS: The 17 patients hospitalized for hematomas were 9 women and 8 men with a mean age of 71 years. Thirteen patients were treated with: antivitamin K (5 cases), low molecular weight heparin (3 cases), anti-platelets (4 cases), or a combination of antivitamin K and anti-platelets (1 case). Four patients had no antivitamin K or anti-platelet treatment; their coagulation control was normal and they were younger than the patients taking a treatment (55 versus 76 years). The hematomas always involved the lower limbs. The clinical aspect was: simple hematoma (3 cases), inflammatory or over-infected hematoma (11 cases) and post-hematoma ulceration (3 cases). Seven patients were febrile either before or during their hospitalization. A context of trauma was noted in 10 patients. In the 9 patients treated with antivitamin K or low molecular weight heparin, overdosing was documented in 5. The treatments received before hospitalization were: general antibiotherapy (7 cases), local antibiotherapy (1 case) and low molecular weight heparin (7 cases). DISCUSSION: Hematomas of the legs usually occur in elderly patients, treated with anticoagulants or anti-platelets. They present in the form of ecchymotic tumefaction, frequently inflammatory or febrile. Therapeutic overdosing is common. The ratio with the erysipelas hospitalized in our department is of 1/8; over the past 5 years we have observed a mean of 3 cases per year. Hence they are not uncommon and dermatologists must be aware of their clinical aspects and the circumstances in which they occur.
INTRODUCTION: Pemphigus vegetans (PV) is a rare type of pemphigus vulgaris. We report a patient with pemphigus vulgaris relapsing as an isolated vegetative tumour. CASE REPORT: A 59-year-old man was seen in February 2001 for a tumour on the right groin. He had received systemic corticosteroids and cyclophosphamide for pemphigus vulgaris from 1974 to 1985, and he had been in complete remission since 1985. At the time of evaluation, a 10 x 5 x 5 cm, smooth vegetative tumour was seen on the right groin. Biopsies showed spongiosis, acanthosis and some acantholysis. Direct immunofluorescence showed strong deposition of immunoglobulin G within the intercellular substance of the epidermis. Indirect immunofluorescence revealed anti-intercellular antibodies at a titer of 1/800. Immunoblot analysis showed reactivity with the 130 kD pemphigus vulgaris antigen. PVg was diagnosed. Local corticosteroid treatment was initiated. The patient was disease-free at follow-up three years later. DISCUSSION: Localised forms of pemphigus are very rare. Twenty four other cases have been reported among them just one case of localised PV. Our case report is very unusual because of the variability of the expression of the disease, the high antibody level, the absence of trigger factors, and the efficacy of the local corticosteroid treatment.
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BACKGROUND: The Baboon syndrome is a form of systemic contact dermatitis. We report the case of a patient who presented a Baboon syndrom following oral medication with betamethasone. CASE REPORT: A 58 year-old man had consulted for eczema involving the groin, the buttocks and the axillae. It was clinically a baboon syndrome related to oral betamethasone (Celestene) treatment, ingested 48 hours earlier. The exploration with a patch-test confirmed the sensitization to betamethasone. This exploration also showed a sensitization to all four classes of corticosteroids. Prolonged withdrawal of all corticosteroids led to the clear improvement of his eczema. DISCUSSION: The baboon syndrome of this patient was the symptom of a systemic eczema due to betamethasone. The patient was sensitized by the percutaneous route. The application of many topical corticosteroids had provoked this polysensitization. It was impossible to consider a safe corticosteroid for this patient.
BACKGROUND: Pseudoxanthoma elasticum (PXE) is normally associated with mutations in the ABCC6 gene. A PXE phenotype without mutations in ABCC6 has been described in Greek and Italian patients presenting with beta thalassemia. We attempted to determine the incidence of beta thalassemia in a cohort of French patients with PXE. PATIENTS AND METHODS: Fifty patients with PXE were included in the study. Laboratory examinations comprised hemoglobin electrophoresis, ABCC6 gene study and in some studies: mutation analysis, beta-globin gene. RESULTS: No cases of beta thalassemia were diagnosed in this cohort of French patients with PXE. However, 20% of the latter exhibited a significant but isolated (i.e. without microcytic anemia) increase of hemoglobin A2 (HbA2). Statistical comparisons showed no difference in terms of geographical origin or severity of PXE between patients with high levels of HbA2 and those with normal levels of HbA2 other than the extent of cutaneous involvement. Study of the beta-globin gene displayed mutations only in the two patients with the highest recorded levels of HbA2. ABCC6 + beta-globin digenism was ruled out of the pathogenesis of PXE. DISCUSSION: The PXE phenotype seen in some patients with beta thalassemia appears to be associated with epigenetic modification of ABCC6 transcription and depends specifically on the beta globin locus. Isolated increase in HbA2 is probably a laboratory marker for PXE. Here again, a functional epigenetic reaction between ABCC6 and the beta-globin locus was suspected. However, these reciprocal interactions are clearly unequal since the change in ABCC6 transcription occurring during the course of beta thalassaemia is responsible for a PXE phenotype while increased HbA2 during the course of PXE has no clinical consequences.
Enamel thickness has assumed unique importance in the debate about the hominid status of Ramapithecus, despite the fact that there is little agreement about the meaning of 'thick enamel' or the significance of enamel thickness for hominoid taxonomy. My aim here is to evaluate the usefulness of enamel thickness and microstructure as characteristics for determining the relationships of the later Miocene hominoids, based both on a quantitative study of enamel thickness in extant hominoids and four species of later Miocene Sivapithecus (including 'Ramapithecus') and on scanning electron microscope analysis of enamel microstructure. Four categories of enamel thickness are defined metrically here and have been related to enamel microstructure and developmental rates. Thin fast-formed (pattern 3) enamel represents the ancestral condition in hominoids; it increased developmentally to thick pattern 3 enamel in the great ape and human clade and that condition is primitively retained in Homo and in the fossil hominoid Sivapithecus (including 'Ramapithecus'). Enamel thickness has been secondarily reduced in the African apes and also, although at a different rate and extent, in the orang-utan. Thick enamel, previously the most important characteristic in arguments about the earliest hominid, does not therefore identify a hominid.
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The ultrastructural features of solid cell nests (SCN), made of squamous cells, and associated calcitonin cells (C cells), of the thyroid gland were studied in only a few cases in humans. A study was performed on 8 paraffin-embedded SCN, postembedded in Epon, to look for their ultrastructural features. Immunohistochemical analysis using calcitonin antibody was performed on semithin sections of SCN to explore the presence of C cells. Three cases (37.5%) of SCN were positive for calcitonin, and electron-dense secretory granules were observed in the cytoplasm. In two of these cases, an increased number of C cells in the adjacent thyroid parenchyma was observed. The presence of ciliated and lymphoid cells, in addition to intracytoplasmic microvacuolar and microfollicular (microglandular) structures, was noticed. Ciliated cells have already been reported in embryonic rests of human and animals, but ultrastructurally for the first time in human SCN. The presence of microfollicular structures, intracytoplasmic microvacuolar, secretory granules features, and ciliated cells, in addition to lymphoid cell, suggests the existence of a common ultimobranchial stem cell for C cells or for one or more cell types of the thyroid gland.
The effect of treating the surface of a polyester vascular prosthesis with a novel fluoropolymer before sealing the graft with gelatin has been evaluated in a canine thoracoabdominal bypass model. The healing behavior of the Fluoropassiv graft was compared with that of the Gelsoft ERS prosthesis used as control for prescheduled periods of implantation ranging from 4 hr to 6 months. Both series of explanted grafts were analyzed using macroscopic, histologic, and scanning electron microscopic observations, and by determining the prostacyclin/thromboxane A2 ratio (PGI2/TXA2) and the thrombogenicity of the luminal surface by means of labelled platelets and fibrin deposition. Chemical analysis of explanted and cleaned graft segments was performed using electron spectroscopy for chemical analysis, differential scanning calorimetry, and contact angle methods. No difference in platelet and fibrin deposition or PGI2/TXA2 secretion by the luminal surface was observed between the treated and the control grafts at any implantation period. On the other hand, pathologic investigation has revealed that, although there is no difference between the two grafts during the first month, the healing sequence of the Fluoropassiv graft appeared more complete and mature than the control graft after 3 and 6 months. Differences were observed in the extent of collagenous internal capsular development, endothelialization, and tissue penetration into the knitted structure. The presence of fluorine and a higher contact angle at the surface of all the explanted fluoropassivated grafts is believed to have been responsible for reducing the inflammatory response and enhancing the long-term healing behavior of this novel prototype device over the control gelatin sealed prosthesis.
To evaluate recent developments in the design and production of polyester vascular prostheses in eastern Europe, a series of in vitro physical and chemical tests and an in vivo study was performed on three new prototype devices from the Czech Republic and one from Poland. The in vitro results for these four prostheses, referred to as the Ra-1n (warp knitted, uncrimped), Ra-1v (warp knitted, crimped), Mikrofroté (weft knitted, uncrimped), and Dallon (warp knitted, crimped) prostheses, were compared against values for three commercial devices of western origin, namely the Triaxial, the Vasculour II, and the Cooley II grafts. The animal trial involved implanting the four prototype devices as a thoracoabdominal bypass in dogs for eight different periods ranging from 4 hrs to 6 months and undertaking histologic and structural investigations on the retrieved grafts. Because of its poor long-term dimensional stability in vivo, the continued use of a weft knitted structure, like the Mikrofroté prosthesis, is to be deprecated. Conversely, the introduction of a more dimensionally stable warp knitted structure in three prototypes is to be acknowledged. However, the presence of surface contaminants was most likely responsible for the excessive inflammatory reaction generated by all four prostheses during the first month in vivo, which resulted in delayed healing performance. In addition, an unusually high surface carbon-oxygen ratio suggests that the crimping process needs further refinement. Improved cleaning and packaging procedures are essential before these products can complete against existing commercial prostheses of western origin. In conclusion, these new developments illustrate that the technology of warp knitting, which is now spreading worldwide, should be evaluated.
To find a nonabsorbable suture material that is equivalent to polypropylene in ease of handling and tensile properties, and that has low thrombogenicity and tissue reactivity but improved biostability, some researchers and clinicians see merit in considering the suitability of monofilaments made from polyvinylidene fluoride. The current animal study investigated the relative biocompatibility and biostability of these two suture materials by using them to anastomose a polyester arterial prosthesis in a canine thoracoabdominal bypass model for 10 periods of implantation ranging from 4 hr to 2 years. Biocompatibility was assessed with light and scanning electron microscope examinations of the explanted sutures, and biostability of the cleaned sutures was determined by Fourier transform infrared spectroscopy and scanning electron microscope analysis. The polyvinylidene fluoride and polypropylene sutures were found to have similar handling and healing characteristics. During the first months in vivo, both types of suture experienced a temporary increase in carbonyl group absorption that coincided with the duration of the inflammatory response. After 1 and 2 years in vivo, the explanted polypropylene sutures showed visual evidence of surface stress cracking. This was not found with the explanted polyvinylidene fluoride sutures. These results suggest that polyvinylidene fluoride may be more biostable than polypropylene in the long term.
The rectal and stomal routes for administering analgesics are discussed as alternatives to invasive, parenteral routes when a patient is unable to take medication by mouth. The ET nurse has an important role in reminding members of the health care team about these routes and in teaching patients and family members (i.e., caregivers) to use them properly.
We have identified a putative 35-kilodalton protein that colocalizes with microtubules and displays a unique spatial and temporal distribution during the cell cycle of HeLa cells. This protein has been given the designation MSA-35. MSA-35 first appears in association with microtubules and centrosomes of interphase cells exhibiting centrosome separation as a prelude to cell division. This protein is found in conjunction with kinetochore microtubules throughout their appearance. MSA-35 transiently associates with interpolar microtubules following anaphase and the pattern of MSA-35 reactivity in telophase cells suggests that there are at least seven domains within the intercellular bridge. The distribution of MSA-35 during and following recovery from mitotic arrest with nocodazole suggest that it is also present at low levels in interphase cells, can associate with interphase centrosomes, and colocalizes with nascent microtubules. The complex spatial and temporal distribution of MSA-35 indicates that it may be necessary for a series of events in the mitotic process such as the bundling of microtubules.
BACKGROUND: Does the prenatal ascertainment of isolated mild ventriculomegaly increase the a priori risk for aneuploidy when isolated or not associated with advanced maternal age? Does isolated mild ventriculomegaly increase the risk for pediatric developmental delay? METHODS: The Wayne State University (WSU) Reproductive Genetics abnormal case data base and the Madigan Army Medical Center (MAMC) experience were reviewed to compare the rates of aneuploidy for cases with fetal ventriculomegaly. Cases were classified by maternal age and associated sonographic markers of aneuploidy. Aneuploidy rates were compared between the isolated ventriculomegaly, ventriculomegaly with advanced maternal age (AMA), and ventriculomegaly associated with multiple anomalies. Rates of aneuploidy were compared to identify association. RESULTS: A total of 118 cases with ventriculomegaly were identified for comparison. Ninety-four cases were identified in the WSU cohort; 46 demonstrated isolated ventriculomegaly alone, and aneuploidy was present in 3/25 (12%) with invasive fetal testing, 0/24 (0%) cases in the MAMC cohort demonstrated aneuploidy. Isolated mild ventriculomegaly cases at MAMC were identified for further tests. DISCUSSION: Although the two study populations vary in age and risk distributions, the attributable risk for isolated mild ventriculomegaly poses a counseling conundrum due to the neurodevelopmental implication of this minor dysmorphism more so than its association with aneuploidy.
Cholesteryl ester transfer protein (CETP) mediates an important pathway for reverse cholesterol transport. Concentrations of CETP in fasting plasma were measured by radioimmunoassay in two different groups of hyperlipoproteinemic subjects. Plasma CETP concentrations measured by radioimmunoassay correlated closely with cholesterol ester transfer activity in normal plasma (r = 0.86). In the first group of 58 patients, plasma CETP concentrations were significantly increased, as compared with those in 79 normal subjects and in hypercholesterolemic (+26%) and combined hyperlipoproteinemic (+25%) subjects but were not altered in moderately hypertriglyceridemic subjects. Marked elevations in plasma CETP levels were documented in patients with dysbetalipoproteinemia (+68%) and severe chylomicronemia (+85%). Similar results were obtained in a second population of 50 hyperlipoproteinemic subjects. Significant correlations were found between plasma CETP levels and total cholesterol (r = 0.52), very low density lipoprotein (VLDL) cholesterol (r = 0.63), and apolipoprotein E concentration (r = 0.40). Correction of the lipoprotein phenotype by dietary means resulted in significant reductions in plasma CETP concentrations in patients with chylomicronemia and dysbetalipoproteinemia. In these subjects, plasma high density lipoprotein cholesterol concentrations increased as CETP decreased. These studies indicate that CETP levels increase in association with enhanced peripheral cholesterol transport via low density lipoprotein, beta-VLDL, or chylomicron remnants.
Overwhelming statistics have been published regarding the success of radiation therapy in the management of laryngeal carcinoma. The fate of those patients whose cancers are not controlled by radiotherapy is often left to speculation. An analysis is made of 61 patients with early and advanced laryngeal cancer treated initially with radiation therapy and subsequently operated upon because of recurrent or persistent tumor. Frequently, diagnosis of recurrence is difficult or delayed. Preservation of voice can only be accomplished when recurrence of T1 and T2 lesions is detected early and strict criteria are followed. Conservation surgery is not feasible for early lesions which progress after radiation failure. Advanced T2 and T4 lesions which become radiation failures also require laryngectomy for salvage. In cancer of the larynx, there is a definite, identifiable group of patients in whom surgery would be advisable as the initial therapy.