Reliability of hemostasis biomarkers is affected by time-dependent intra-patient variability

Essentials Nucleosomes and free DNA are two newly described biomarkers in venous thromboembolism (VTE). Reliability of nucleosomes, plasma free DNA and conventional hemostasis markers were studied. Hemostasis biological parameters vary over a short time-frame in VTE patients. Hemostasis biological parameters also vary over a short time-frame in healthy controls.

SUMMARY

Background Previous studies have associated neutrophil-derived circulating nucleosomes and plasma free DNA with venous thromboembolism (VTE). However, there are few data concerning these two biomarkers and no studies have compared the reliability of nucleosomes and plasma free DNA against that of conventional hemostasis markers. Objectives We performed a 3-year prospective study of nucleosomes and plasma free DNA levels in comparison with conventional hemostatic biomarkers and blood cells. Patients/Methods Fifteen healthy controls and 22 randomly selected patients with a history of VTE were followed monthly for 6 months. The reliability of these markers was evaluated by the intraclass correlation coefficient (ICCs). Results and Conclusions In healthy controls and patients, we found a low reliability for nucleosomes and plasma free DNA, with ICCs at 0.538 (95% confidence interval [CI], 0.334-0.764) and 0.091 (95% CI, -0.026-0.328), respectively, in the healthy controls, and at 0.213 (95% CI, 0.042-0.463) and 0.161 (CI 95%, 0.008-0.398) in the patient group. For the conventional hemostasis biomarkers and for blood cells, reliability ranged from poor to good in the healthy volunteers and from poor to acceptable in the patient group. Our study shows for the first time that hemostasis biological parameters spontaneously vary over a short time-frame in VTE patients and, more surprisingly, in normal individuals. The clinical value of such intra-individual variations is currently unknown. This variability might mean reinterpreting diagnostic or prognostic models based on static evaluation of individuals. Studying the intrinsic value of individual patterns of markers' variability is warranted.

Reflection on the measurement and use of the topography of the indentation imprint

The goal of this paper is to study the main uses of the residual imprint of the indentation test. It also discusses the different technologies and methods employed in this context. The difficulties encountered when trying to exploit the full potentials of the imprint are thoroughly examined. A survey of the literature on the quantification of the pile-up clearly shows that there is a lack of consensus on the measurement of the residual imprint as well as on treatment methods. Therefore, in order to widen the application fields of the indentation residual imprint, relevant and standardized indicators should be established.

[Evaluation of an automated method for measuring low-density lipoprotein cholesterol]

We evaluated an automated method for measuring low-density lipoprotein cholesterol (LDL-cholesterol) with Integra 800 (Roche Diagnostics). This method uses detergents which show selectivity for the different lipoproteins. Our evaluation has shown a within run imprecision of 2% and a between-assay imprecision of 1.2%. This method was not perturbed by haemoglobin, bilirubin or lipids. However, the reagents remain expensive: we will use it when calculation or interpretation of lipid results are not possible.

Role of laparoscopy in blunt perforations of the small bowel

BACKGROUND

The purpose of this study was to determine whether laparoscopy could improve our ability to diagnose and treat perforations of the small bowel.

METHODS

From 1985 to 2001, among 250 patients admitted for a blunt abdominal trauma, 195 surgical explorations were performed, comprising 42 laparoscopies. On admission, 108 patients underwent an abdominal ultrasonography (US) and 104 a computed tomography (CT). Thirty-nine patients had a blunt small bowel trauma (BSBT) that was explored and/or treated by laparoscopy (n = 15) or celiotomy (n = 24). We compared the patients who underwent emergency surgery (23) and those who were operated on after a mean delay of 51 h.

RESULTS

On admission, for detecting free intraperitoneal fluid with a BSBT, the sensitivity of CT was 93.3% and specificity was 13.6%. Regarding the 23 patients who underwent emergency surgery, 8/20 had positive US and 10/15 had positive CT, whereas the 15 celiotomies and 8 laparoscopies indicated BSBT. Regarding the 16 patients who underwent delayed surgery, 9 patients underwent a celiotomy and 7 a laparoscopy; all BSBTs were diagnosed. In searching for BSBT, the sensitivity and specificity of laparoscopy were both 100%, whereas the sensitivity of CT was 83.3% and specificity was 22.2%. Twenty of 23 patients undergoing emergency surgery had bowel suture repair compared to 3/16 after delayed surgery. In contrast, a resection was necessary in 10/12 patients treated after a delay compared to 2/17 operated in emergency. Five BSBTs were sutured by laparoscopy, whereas 10 required conversion. Laparoscopy avoided celiotomy in 15 cases. There were no deaths and no enterostomy.

CONCLUSION

In hemodynamically stable patients with blunt abdominal trauma, laparoscopy safely and effectively identifies small bowel injuries. Early recognition of these injuries and timely surgical treatment offer the best prognosis.

Polypeptide composition of an adenovirus type 5 used in cancer gene therapy

For cancer gene therapy, a recombinant adenovirus serotype 5 named RPR/INGN201 has been constructed by susbtitution of the E1 region with human tumor suppressor gene p53. The protein components of RPR/INGN201 virions were separated by reversed-phase HPLC and were individually identified by electrospray time-of-flight mass spectrometry and N-terminal sequencing, both on intact proteins and on their proteolytic fragments after trypsin digestion. Twenty-five peptide components of the proteome (including fiber) with greater than 0.25-0.5% contribution to the protein content of the virus were identified and characterized. Fiber was confirmed to be partially glycosylated (both the non-glycosylated and the monoglycosylated states were identified), and two proteins were isolated and identified as phosphorylation derivatives, namely protein V (non-phosphorylated and monophosphorylated) and protein IIIa (mono- and diphosphorylated). This new analytical tool proved to be very useful not only for refining our current knowledge of the polypeptide repertoire of purified infectious virions but also for monitoring and very rapidly identifying structural modifications resulting from changes in the manufacturing process. It was also used successfully for the characterization of various adenoviral constructs.

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

[Prosthetic treatment of bilateral inguinal hernias via laparoscopic approach or Stoppa procedure]

AIM OF THE STUDY

The aim of this prospective non-randomized study was to compare Stoppa's technique to laparoscopic approach in totally extraperitoneal repair of bilateral inguinal hernia.

PATIENTS AND METHOD

From December 1996 to December 1998, 117 consecutive patients with 234 hernias underwent either Stoppa's technique (74 patients) or a totally extraperitoneal laparoscopic approach (43 patients). Patients were randomized in two groups according to the surgeon to whom they were referred. All patients were reviewed in December 1999.

RESULTS

There was no mortality. Complications occurred in 3% of patients after Stoppa's technique (group S) and in 4% of patients in the laparoscopic group (group L). The conversion rate was 7% (3 cases). Postoperative analgesia use, hospital stay, and duration of disability were significantly shorter in group L, the cost was lower, but the operating time was significantly longer than in group S. Recurrence rates were similar in the two groups: 2% in group S, 1.1% in group L.

CONCLUSION

The laparoscopic approach appears to be preferable to Stoppa's technique in the treatment of bilateral inguinal hernia.

[Excision of the duodenojejunal angle for tumor. From simple excision to locoregional excision]

Locoregional extensions are often observed in tumors of the duodenojejunal angle, either because of their anatomic situation or in cases diagnosed late. Endoscopic and radiographic explorations (basically abdominal CT scan) are indicated to search determine the degree of extensions to neighboring organs and vessels. Colic and mesocolic involvement are at the limit of preoperative explorations. Based on 4 observations of increasing complexity, we describe our operative strategy allowing tumor exeresis in a single block. Extension to the superior mesenteric artery is the main contraindication for exeresis.

[Cystic and papillary tumor of the pancreas: diagnostic and developmental uncertainties. Apropos of a case]

We reported a case of papillary and cystic tumor (Frantz's Tumor) associated with familial adenomatous polyposis in a young man, 29 years old. This case emphasized the interest of fine needle biopsy and the difficulties for determination of the final pathology. Close long term follow up is essential as local recurrencies and metastasis in the long term had been recorded, undergoing resection with curative intent. Papillary and cystic tumors should be resected.

[Cystic lymphangiomas of the colon. Apropos of 2 cases]

The authors report about two observations of cystic lymphangioma of the right colon. The patients complained of intermittent abdominal pain. Preoperative diagnosis is based on endoscopic findings (2 cases) and computed tomography films (1 case). A colonic carcinoma is associated in one case. Endoscopic polypectomy will be curative for pedunculated or small lymphangiomas. In other cases segmental resection seems to be the treatment of choice.

Autopsies of sudden infant death syndrome--classification and epidemiology

An enquiry into sudden infant death syndrome (SIDS) in 1987 furnished us with detailed epidemiological data for 281 cases that underwent a thorough post-mortem examination. This analysis uses these data to evaluate the role the autopsy plays in explaining sudden death. The cases were classified into three diagnostic groups: explained causes of death (group 1), unexplained deaths with anomalies (group 2), and no anomaly (group 3). These 281 cases show the three essential features that characterize SIDS: over-representation of males, increased deaths during the second and third months of life, and increased deaths during winter. The autopsy examination revealed that many of these deaths had a medical explanation. Almost half were assigned to group 1. At the time of autopsy, no precise pathology could be diagnosed for 147 deaths; of these, 140 showed histological anomalies. There were only seven sudden deaths for which no abnormal sign was evident at the autopsy. These results are compared with those of similar studies and discussed in connection with three factors: the initial selection of cases, the nature and degree of the investigations, and the possible interpretations of the symptoms uncovered.

[Well-differentiated papillary mesothelioma of the peritoneum: an attenuated malignant tumor. Review of the literature apropos of a case]

The authors present a new case of a well-differentiated papillary mesothelioma of the peritoneum. This is an uncommon tumor which have a slow evolution like a low malignant potential tumor. But, because of its tendency to recurrence, the designation of Well-Differentiated Tumor is better. The diagnosis with others peritoneal tumors is sometimes difficult, especially with the Peritoneal Serous Tumors. Tumor recurrence must be treated by curative surgery. Adjuvant therapy is discussed for the diffuse form.

[Gastric adenocarcinomas (excluding linites). Prognostic factors apropos of a series of 101 cases]

The incidence of some factors on prognosis of adenocarcinoma of the stomach was evaluated in 101 cases. Linites as well as cancers of the cardia were excluded from the analysis. There were 47 total gastrectomies with more or less extensive node dissection and 54 partial gastrectomies. Overall actuarial survival was 34.5% despite the large number of advanced stage cancers (70% positive lymph nodes, 35 with invasion of neighbouring organs, 13 cases of carcinosis and 13 with liver metastasis). Univariate analysis showed that the following factors were associated with poor prognosis: invasion of the serous layer, nodal involvement, emboli, degree of differentiation. Peritumoural reactional lymphoid infiltration, the presence of a chronic gastritis and intestinal metaplasia were found to be favourable factors. Gastric resection appeared to have less impact than the quality of the nodal dissection. These findings emphasize the importance of extensive dissection of the lymph nodes (survival ranging from 31 to 78% depending on the node score). Extensive dissection, allowing better locoregional control of the disease, improved prognosis whatever the size of the tumour (14.8% survival in case extending to neighbouring organs). The only exceptions were palliative exereses and N4+ cases.

[Cancer of the penis: the value of systematic biopsy of the superficial inguinal lymph nodes in clinical N0 stage patients]

From 1985 to 1991, bilateral surgical biopsy of the superomedial group of superficial inguinal lymph nodes, considered to be the first draining nodes, was performed in 24 patients with clinical stage T1-3 N0 M0 squamous cell carcinoma of the penis at the same time as surgical treatment of the primary. This procedure was technically successful in every case, but no lymph node metastases were detected. As bilateral biopsy was negative in these 24 patients, clinical surveillance was implemented: review every 2 months for 2 years and self-palpation by the patient. Seven patients (29.1%) developed one or more suspicious ilio-inguinal lymph nodes after a mean interval of 11.85 +/- 8.02 months: 1) In 6 patients, bilateral ilio-inguinal lymph node dissection was then performed, confirming the neoplastic nature of the inguinal node metastases without iliac metastases in 3 of these patients. 2) As the remaining patient presented with unilateral iliac node metastases, proven histologically by surgical biopsy, systemic chemotherapy was introduced prior to ipsilateral inguinal lymph node dissection. This finding questions the theory according to which the sentinel superomedial inguinal node constitutes the first draining node and demonstrates the existence of several pathways of lymphatic drainage towards superficial and deep inguinal nodes. This biopsy, which was always negative in our series, is insufficient to guide our therapeutic approach in clinical N0 patients. The decreased complication rate following inguinal lymph node dissection should certainly encourage us to prefer surgery, particularly superficial inguinal lymph node dissection with preservation of the great saphenous vein.

[Incidence of autopsies in France. Consequence on the estimation of sudden death rate according to regions. Results from an epidemiologic survey on postneonatal mortality]

In order to assess the actual rate of sudden infant death in France, an epidemiological survey was carried out. All the deaths of the postneonatal period were investigated from September 1986 to December 1987. The parents of the babies and the certifying physicians were involved in the survey, the results of the post mortem investigations were recorded. That material showed a low rate of necropsies among the sudden infant deaths (31% at the national level) and wide variations in the rates between the French regions (from 55 to 7%). Nevertheless the results of the autopsies as well as the clinical aspects allowed to calculate the unexplained sudden infant death rates by region according to the Beckwith's definition. These rates are ranging from 0.8 to 1.9 per thousand live births (mean 1.3).

Epidemiology of schistosomiasis in the riverine population of Lagdo Lake, northern Cameroon: mixed infections and ethnic factors

The distribution of S. mansoni and S. haematobium was evaluated using a cluster sampling technique in 15 fishing villages around Lagdo lake and 2 inland villages in northern Cameroon. The overall prevalence of S. haematobium infection was 26% and of S. mansoni was 15%, while 7% of the population sampled had mixed infections. The highest prevalences were observed in larger villages (greater than 200 persons) where sanitary conditions were poor. The intensity of S. haematobium infection in those also infected with S. mansoni was two to three times greater than in those with S. haematobium alone. Differences in prevalence among ethnic groups was attributed to occupational and cultural habits. The factors leading to the diversity of the distribution of schistosomiasis within a man-made lake are discussed.

Constitutive mutants in the yeast pheromone response: ordered function of the gene products

The alpha factor pheromone inhibits the division of yeast a cells. A general method was developed for isolating mutants that exhibit constitutive activation of the pheromone response pathway. A dominant allele of the STE4 locus was recovered in addition to recessive mutations in the SCG1 gene. SCG1 and STE4 are known to encode G alpha and G beta homologs, respectively. Analysis of double mutants suggests that the STE4 gene product functions after the SCG1 product but before the STE5 product.

Changing the DNA-binding specificity of a repressor

The Mnt repressor of Salmonella phage P22 recognizes a 17 base pair operator. We constructed an Mnt binding site with two symmetric operator-constitutive mutations. We then selected Mnt mutants that have lost the ability to bind the wild-type operator but acquired the ability to bind the mutant operator. Four independent mutations change the same CAC codon in the mnt gene to CCT or CCC. The corresponding amino acid change in Mnt is His6 leads to Pro. DNA binding assays with purified wild-type and mutant proteins confirm the change of binding specificity in vitro. Wild-type Mnt binds strongly to the wild-type operator, but binds the mutant operator with 1000-fold less affinity. The mutant Mnt binds with converse affinities to the two operators.

Sequence determinants of promoter activity

The bacteriophage P22 promoter for the antirepressor (ant) gene, Pant, in the absence of Arc repressor, directs the synthesis of extremely high levels of antirepressor. Overproduction of antirepressor leads secondarily to the failure to produce progeny phage upon lytic infection. A substantial fraction of revertants of P22 arc-amber phage are pseudorevertants that have acquired additional mutations that decrease the activity of the ant promoter. DNA sequence analysis of 72 independent Pant "promoter-down" mutations reveals more than 25 different alterations that define two regions critical for promoter activity. With few exceptions, these promoter-down mutations decrease the homology of Pant with the consensus promoter sequence, demonstrating that the conserved features among a large number of different wild-type promoters are the determinants of promoter strength.l In general, different substitution mutations at the same site within the promoter have similar effects, resulting in either a severe or a mild reduction in promoter activity.