Hans Oosting

Extracapsular growth of lymph node metastases in squamous cell carcinoma of the vulva : the impact on recurrence and survival

Background. Patients with squamous cell carcinoma of the vulva who present with multiple positive groin lymph nodes have poor survival. Growth of cancer through the capsule of the groin lymph nodes recently has been identified as an important prognostic factor for survival in that patient group. The objective of this study was to determine the influence of several clinicopathologic parameters on the pattern of recurrence and survival.

Linearizing: a method for analysing and synthesizing nonlinear systems.

SummaryPhysical and especially biological systems behave many times in such a way that the methods of linear system analysis are not adequate, even when “small” signals are used.This paper presents an approach which has been applied succesfully in the analysis of certain nonlinear biological systems. The method is capable to recognize in these systems the linear and nonlinear elements. Furthermore these elements can be characterized and a functional sequence can be detected. Applications of the method are illustrated for the analysis of two biological systems and the synthesis of a physical system.

Thoracic Duct in Patients With Multiple Organ Failure: No Major Route of Bacterial Translocation

OBJECTIVE To determine whether translocation of bacteria or endotoxin occurred into the thoracic duct in patients with multiple organ failure (MOF). SUMMARY BACKGROUND DATA Translocation of bacteria or endotoxin has been proposed as a causative factor for MOF in patients without an infectious focus, although it has rarely been demonstrated in patients at risk for MOF. Most studies have investigated the hematogenic route of translocation, but it has been argued that lymphatic translocation of bacteria or endotoxin by the thoracic duct is the major route of translocation. METHODS The thoracic duct was drained for 5 days in patients with MOF caused either by generalized fecal peritonitis (n = 4) or by an event without clinical and microbiologic evidence of infection (n = 4). Patients without MOF who were undergoing a transthoracic esophageal resection served as controls. In lymph and blood, concentrations of endotoxin, proinflammatory cytokines, and antiinflammatory cytokines were measured. RESULTS Endotoxin concentrations in lymph and blood of patients with MOF ranged from 39 to 63 units per liter and were not significantly different from concentrations in patients without MOF. The quantity of endotoxin transported by the thoracic duct in the study group was small. In patients with MOF, low levels of proinflammatory cytokines and high levels of antagonists of these cytokines were found. CONCLUSION This study provides evidence that translocation (especially of endotoxin) occurs into the thoracic duct. However, these data do not support the concept that the thoracic duct is a major route of bacterial translocation in patients with MOF.

Second-trimester placental volume measurement by ultrasound: Prediction of fetal outcome

A prospective study evaluated sonographic second-trimester placental volume measurements in the prediction of fetal outcome. A parallel section scan method was used. Abnormal fetal outcome could be predicted with a sensitivity and specificity of approximately 90%. Evidence is given that fetal growth retardation is preceded by abnormal placental development in the first half of pregnancy. To a large extent, fetal birth weight and outcome are results of placental development and the ability of the placenta to meet the growing needs of the fetus as determined by its intrinsic growth potential.

Intra‐observer and inter‐observer reliability of the pulsatility index calculated from pulsed Doppler flow velocity waveforms in three fetal vessels

Objective Study of the intra observer and inter observer reliability of the pulsatility index, calculated from pulsed Doppler recordings of three fetal vessels.

Fetal brain sparing is associated with accelerated shortening of visual evoked potential latencies during early infancy

OBJECTIVE Our purpose was to assess the effects that fetal growth restriction exerts on the myelination of the developing brain. STUDY DESIGN Fetal haemodynamic centralization, an adaptive strategy to growth restriction caused by placental insufficiency, was determined by Doppler ultrasonography. Infants with a raised ratio between umbilical artery pulsatility index and cerebral artery pulsatility index are severely growth restricted. Visual evoked potentials give information on the degree of brain myelination. Shortening of visual evoked potential latencies is a normal feature of myelination. In a consecutive series of 105 Neonates, visual evoked potentials were recorded at the corrected ages of 6 months and 1 years. Correction for possible confounders, such as cranial ultrasonographic findings, gestational age, and head circumference, was performed. RESULTS At 6 months, infants with a raised umbilical artery/cerebral artery pulsatility index ratio have shorter visual evoked potential latencies. Opposite of neonates with a normal umbilical artery/cerebral artery ratio, they show no postnatal maturational shortening of visual evoked potential latencies. CONCLUSION Accelerated neurophysiologic maturation, found in infants with a high umbilical artery/cerebral artery ratio, might be the result of a beneficial adaptive process to severe fetal growth restriction.

Platelet aggregation, disc haemorrhage and progressive loss of visual fields in glaucoma. A seven year follow-up study on glaucoma.

Platelet aggregationin vitro, deterioration of visual field defects (VFD) and the prevalence of disc haemorrhages (DH) were assessed in 49 patients with primary open angle glaucoma (POAG) and compared with the findings for 67 individuals with suspected glaucoma (GS) in a seven-year follow-up study (range 5.8 to 8.2 years). The percentage patients with spontaneous platelet aggregation (SPA) was higher for POAG patients with visual field deterioration (60%) than both POAG patients without progressive loss of visual fields (12.5%; P<0.005) and those with suspected glaucoma (22.4%; P<0.005). The occurrence of DH was higher among POAG patients with progressive loss of visual field (28%) compared to the GS group (8.4%; P<0.025) and the group of patients consisting of POAG patients without deterioration of VFD and GS (9.9%; P<0.05). DH also occurred more often in patients with low tension glaucoma (41.6%) than in the remaining POAG patients (13.5%; P<0.05). No relation between the patients with SPA and the patients with DH was observed.

Anorectal surgery in human immunodeficiency virus-infected patients

PURPOSE: Anorectal disease is commonly found in human immunodeficiency virus (HIV)-infected patients. The aim of this study was to determine the spectrum of anorectal disease, its surgical treatment, clinical outcome, and its relation to immune status. METHODS: Medical records of all HIV-infected patients with anorectal pathology that required surgical treatment from January 1984 to January 1994 were retrospectively reviewed. Patients were divided into five different groups: common anorectal pathology (hemorrhoids, polyps, Group A); condylomata acuminata (Group B); perianal sepsis (abscesses, fistulas, Group C); anorectal ulcers (Group D); malignancies (Group E). RESULTS: Eighty-three patients needed 204 surgical consultations (13 percent conservative, 87 percent operative) for 170 anorectal diseases. Fifty-one patients had multiple anorectal pathology. Operative intervention resulted in adequate wound healing and symptom relief in 59 percent of patients, adequate wound healing without relief of symptoms in 24 percent of patients, and disturbed wound healing in 17 percent of patients. Disturbed wound healing was related to type of anorectal disease (P<0.001) and to preoperative CD4+-lymphocyte counts (P<0.01). Disturbed wound healing and most insufficient immune status were encountered in Groups C, D, and E. Within these groups low CD4+-lymphocyte counts were a risk factor for disturbed wound healing (P=0.004). Median postoperative survival was highest (4.7 years) in Group A, lowest (0.6 years) in Groups D and E, and related to type of anorectal disease (P=0.0001). CONCLUSIONS: The spectrum of anorectal disease is complex. Type of anorectal disease is strongly related to immune status, wound healing, and postoperative survival.

Effect of fetal brainsparing on the early neonatal cerebral circulation.

The effect of antenatal brainsparing on subsequent neonatal cerebral blood flow velocity (CBFV) was studied in very preterm infants. CBFV was determined, using a pulsed Doppler technique, both in the fetal and neonatal period. Neonatally, blood pressure and transcutaneous carbon dioxide tension (TcPCO2) was monitored simultaneously; daily cranial ultrasound examinations were performed. In infants with evidence of brainsparing a higher mean value of CBFV and a different pattern of changes of CBFV during the first week of life was demonstrated compared with infants with normal fetal cerebral haemodynamics. No differences were found in blood pressure and TcPCO2. The incidence of intracranial haemorrhages and of ischaemic echo-dense lesions was also the same for both groups. In a multivariate statistical model gestational age, antepartum brainsparing, and TcPCO2 all contributed significantly in explanation of variation in CBFV. It is speculated that a different setting of cerebral autoregulation related to differences in gestational age or to brainsparing might explain the difference in changes found in neonatal CBFV.

Placental volume measurement by ultrasonography: Evaluation of the method

A method for placental volume measurement by parallel ultrasonographic section scans is presented. An interval of 2 cm between the scans proves most effective. During measurement the patient should lie in the lateral position to prevent caval vein compression. The precision of the method as estimated by the SE is between 10 and 50 ml. The volume measured reflects both placental cellular mass and placental circulating blood volume. Drainage of the latter after delivery causes a fairly large difference between antepartum placental volume and postpartum placental weight (volume/weight ratio 1:6).