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At least 379 records · Page 21Linked to original sources
PubMed1991

Is fetal acidosis in the human fetus maternogenic during labor? A reanalysis.

The purpose of this study was to investigate whether maternogenic fetal acidosis can occur at the time of labor and delivery and to evaluate the extent of the possible maternal contribution to fetal acidosis. We have therefore determined fetal and maternal lactate concentrations and acid-base status under various conditions in 589 women at the end of gestation and during labor. The results show that metabolic acidosis develops in all fetuses because of increased production of lactic acidosis is primarily of fetal origin: 1) the umbilical arteriovenous lactate differences were positive and large in steady-state conditions as well as in depressed newborns; 2) the conditions that could produce a net transfer of lactate from the mother to the fetus, namely a positive maternofetal gradient of lactate and proton, were rarely observed; and 3) the correlation between fetal and maternal lactate levels was very weak, with regression coefficients decreasing from near steady-state conditions to acute stress conditions, indicating that the increase in lactate in the fetus and mother occurs independently. This correlation indicates also that increased maternal lactate production under conditions of labor and delivery can make a contribution by affecting the rate of net transfer from fetus to mother. This is possible in approximately 6% of the fetuses.

Acidosis↗
PubMed1993

Reanalysis of the rat proestrous LH surge by deconvolution analysis.

To evaluate the temporal mechanisms that give rise to the spontaneous proestrous surge of luteinizing hormone (LH) in the rat, we have applied deconvolution analysis to earlier immunoreactive LH concentration vs. time profiles obtained by sampling blood in proestrus at 2- to 3-min intervals in 10 animals over a span of 160-300 min. Six other animals were bled in 6-min intervals on day 1 of diestrus. Deconvolution analysis permitted us to calculate the number, duration, amplitude (maximal release rates), and mass of underlying LH secretory bursts and to simultaneously estimate basal secretion and the half-life of endogenous LH in each animal. Proestrus rats exhibited a significant increase in the number of computer-identified LH secretory bursts per hour (1.8 +/- 0.2 vs. 1.1 +/- 0.01 on diestrus, P < 0.01), with a corresponding reduction in the LH intersecretory burst interval from 61 +/- 6.4 min (diestrus) to 25 +/- 2.7 min (proestrus, P < 0.01). There was a remarkable 16-fold increase in the mass of LH secreted per burst, which rose from 72 +/- 5.2 to 1,230 +/- 200 ng/ml (P < 0.01). This resulted from a sixfold increase in LH secretory burst amplitude and a doubling of burst duration. The total amount of LH released in a burstlike fashion during the proestrous LH surge rose 20-fold, and calculated basal LH secretion increased to approximately 25% of this value. Of interest, the computed half-life of endogenous LH also increased from 10 +/- 1.1 to 19 +/- 3.7 min (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1981

Reanalysis of the refractory period in exertional asthma.

In an effort to determine whether the refractory period in exercise-induced asthma derived from mediator consumption we had seven asthmatic subjects repeatedly perform both exercise and eucapnic hyperventilation at matched minute ventilations under precisely controlled inspired air conditions. We reasoned that, if airway cooling were causing an agent to be released whose depletion resulted in less responsiveness, we should be able to observe this phenomenon irrespective of how cooling was produced. Repetitive exercise at short intervals produced a diminution in the obstructive response that disappeared when the interval between challenges was extended to 2 h. However, the degree of obstruction that occurred after voluntary hyperventilation remained constant irrespective of when the provocations were performed and equaled that seen with the first and last exercise challenge. Because the thermal burdens were identical for each challenge and all time periods, these results are incompatible with mediator depletion and suggest that it may be the secondary sympathoadrenal consequences of repeated exercise that cause the airways to temporarily lose their responsivity.

Asthma↗
PubMedDate not supplied

The cladribine trial in secondary progressive multiple sclerosis: A reanalysis.

In a recent communication, Goodin [1] analyzes several clinical trials to point out serious flaws in both design and interpretation that may invalidate the conclusions that are drawn. We agree with Goodin [1] that the design of clinical studies, particularly of a disease as complex as multiple sclerosis, is extremely difficult. Indeed, a perfectly designed and executed clinical study is a goal that is never achieved because of the problems inherent in providing care to patients while attempting to evaluate a therapeutic modality. Specifically, in the study of multiple sclerosis, none of the clinical trials of the use of interferons could be considered fully satisfactory: blinding is actually impossible because of the symptoms that are experienced by patients when they receive active drug but not when they receive placebo. It is quite fashionable and not at all difficult to find problems in the conduct of clinical studies; indeed, if all clinical studies with flaws were discarded, there would be no acceptable clinical studies.

Antineoplastic Agents↗
PubMed1995

Manic-depressive illness and linkage reanalysis in the Xq27-Xq28 region of chromosome X.

Inconsistent findings in X linkage studies of manic-depressive illness (MDI) have been ascribed to the presence of phenotypic uncertainties (incomplete penetrance), considerable variation in form and severity of MDI, and the likely presence of phenocopies (or false positives). In order to address some of these issues, previous X linkage data with colour blindness, glucose-6-phosphate dehydrogenase deficiency, and blood coagulation factor IX (F9) markers were reanalysed using a narrow and a broad definition of MDI. Our results confirm the X-linked hypothesis for MDI genetic transmission when controlling for diagnostic variation. The lod score (log of odds ratio) is reduced for a more conservative definition of the disease, but nevertheless remains significant. However, conclusive linkage between the MDI gene and the F9 gene in the Xq27 region is not maintained in our series. Our findings emphasize the need to reanalyse previous genetic data with more sophisticated diagnostic and statistical techniques.

Adult↗
PubMed1978

Reanalysis of the preoptic afferents and efferents involved in the surge of LH, FSH and prolactin release in the proestrous rat.

In order to elucidate neural pathways concerned with the proestrous surge of LH, FSH and prolactin (Prl) release, brain transection or lesion was made acutely under ether anesthesia between 12.00 and 14.00 h of proestrus, and electrochemical stimulation was done under anesthesia with pentobarbital sodium (31.5 mg/kg b.w.) injected at 13.45 h. Transection which interrupted the connection of septum (SEPT), diagonal band of Broca (DBB) and bed nucleus of stria terminalis (BST) with the preoptic-suprachiasmatic area interfered with ovulation and surge of release of all 3 hormones. Isolation of the basal part of the suprachiasmatic area, including the suprachiasmatic nucleus (SCH), blocked ovulation also. Bilateral lesions in the medial preoptic area (MPO) with platinium-iridium electrode blocked ovulation and the surge of LH and Prl release, but not of FSH. Lesions in the SCH blocked ovulation and the surge of LH, but not of FSH and Prl. In the rat with acute isolation of the basal part of the suprachiasmatic area and SCH, stimulation of the MPO failed to induce ovulation and LH release, but was followed by FSH release. Prl release was not inhibited as in the intact rat. When the rat had the antero-SCH cut, stimulation of the SCH induced LH release but not FSH, and the inhibition on Prl release was pronounced. These findings offer evidence that the limbic-forebrain inputs are necessary for the preoptic integration in order to stimulate the proestrous surge of LH, FSH and Prl release. Furthermore, it is possible that separate pathways from the preoptic area to the medial basal hypothalamus are concerned in the stimulation of individual hormones--a restricted route for LH which may pass through the SCH, a diffuse one for FSH which may pass through either the SCH or anterior hypothalamic area, and a relatively diffuse one for Prl which may pass outside the SCH.

Afferent Pathways↗
PubMedDate not supplied

Factors predicting maintenance of sinus rhythm after direct current cardioversion of atrial fibrillation and flutter: a reanalysis with recently acquired data.

A prospective study was conducted to evaluate how many patients maintain normal sinus rhythm after direct current (DC) cardioversion of atrial arrhythmias and to assess factors predictive of long-term success. The study group consisted of 61 patients (45 men) aged 18-88 years (mean age 66 +/- 11 years) who underwent cardioversion at our department from October 1990 to June 1992. Prior to cardioversion, the patients' medical history, medications, heart size on chest X ray, and echocardiographic findings were reviewed. Overall, 41 (67.2%) patients were in atrial fibrillation, while 20 (32.8%) had atrial flutter. Only 15% of the patients had valvular heart disease. Sinus rhythm was restored by DC cardioversion in 47 (77%) patients, none of whom experienced an embolic event prior to discharge. Patients with atrial flutter had a higher conversion rate (95%) than those in atrial fibrillation (68.3%; p = 0.024), and also patients with an arrhythmia for less than 1 week (94.4%) compared to those with a longer or unknown duration (69.8%; p = 0.047). The primary success rate was not influenced by heart size on chest X ray or echocardiographic variables. The study protocol aimed at following up the patients for 1 year after cardioversion. Of the 47 patients who converted to sinus rhythm data are available on 44 for a mean follow-up of 11 +/- 3 months (range 1-14 months), at which time 25 (57%) still remained in sinus rhythm. Heart size on the chest X ray was significantly increased in the group that did not maintain sinus rhythm (p = 0.03) and their left atrial size on echocardiography was slightly increased (p = 0.10). Patients who originally had atrial flutter were more likely to remain in sinus rhythm than those who had been in atrial fibrillation (p = 0.12), as did patients with an arrhythmia for less than 1 week prior to cardioversion in comparison to those with a longer or unknown duration (p = 0.11). Thus, in contrast to previous reports, according to these recent data on a patient population with a low prevalence of valvular heart disease, DC cardioversion can be attempted in most patients with atrial tachyarrhythmias. Clinical factors, heart size on chest X ray and echocardiographic findings should, however, be considered before deciding to perform DC cardioversion.

Adolescent↗
PubMed1984

Articulation rate and its variability in spontaneous speech: a reanalysis and some implications.

It is by now well established that during normal conversation talkers often produce large variation in the rate at which they speak. However, existing research suggests that this modification is largely due to changes in the amount of pausing during conversation, and much less to actual changes in articulation rate, that is, the rate at which the speech itself is produced. In an attempt to examine this issue further, we used a modified measurement procedure to reanalyze the speech data from 30 talkers in an interview situation. In contrast to the earlier analyses, we found that there was indeed substantial variation in articulation rate for these speakers, even within a single utterance of a single talker. The implications of these findings for theories of segmental perception and for models of speech planning are discussed.

Humans↗
PubMed2005

Cost-effectiveness of ambulatory blood pressure: a reanalysis.

Accurate diagnosis of hypertension and prognosis for future cardiovascular events can be enhanced through the use of 24-hour ambulatory blood pressure monitoring. It has been suggested that the use of ambulatory monitoring as a secondary screening for hypertension might be cost-effective. Many needed studies that are related to the calculation of cost-effectiveness for ambulatory monitoring have become available in recent years. More accurate estimates for cost of care, costs for testing, prevalence of white-coat hypertension, and incidence of the transition from normal pressures to hypertension have been reported. This study presents calculations of the cost savings likely to take place when ambulatory blood pressure monitoring is implemented for newly detected hypertensive subjects. These calculations are based on current estimates for cost of testing, cost of treatment, prevalence of white-coat hypertension at baseline, and varying the incidence of new hypertension after the initial screening. The results indicate a potential savings of 3% to 14% for cost of care for hypertension and 10% to 23% reduction in treatment days when ambulatory blood pressure monitoring is incorporated into the diagnostic process. At current reimbursement rates, the cost of ambulatory blood pressure monitoring for secondary screening on an annual basis would be <10% of treatment costs. Calculated savings for use of ambulatory blood pressure monitoring can take place when annual treatment costs are as little as 300 dollars. These estimates should be considered for the management of recently detected hypertension, especially when the risk of future cardiovascular is disease is low.

Blood Pressure Monitoring, Ambulatory↗
PubMed2003

Reanalysis of the final results of the European Carotid Surgery Trial.

BACKGROUND AND PURPOSE: The European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) have shown that endarterectomy reduces the risk of stroke in certain patients with recently symptomatic carotid stenosis. However, they differed in the degree of stenosis above which surgery was reported to be effective. This disparity has led to inconsistent clinical recommendations but may have been due to differences between the trials in the methods of measurement of carotid stenosis and definitions of outcome events. METHODS: To allow direct comparison of analyses from ECST and NASCET, we remeasured the prerandomization ECST carotid angiograms and redefined the outcome events the same way as in NASCET. RESULTS: We randomized 3018 patients and followed them up for a mean of 73 months. Surgery reduced the 5-year risk of any stroke or surgical death by 5.7% (95% CI, 0 to 11.6) in patients with 50% to 69% stenosis (n=646, P=0.05) and by 21.2% (95% CI, 12.9 to 29.4) in patients with 70% to 99% stenosis without "near occlusion" (n=429, P<0.0001). These benefits were maintained at the 10-year follow-up. However, surgery was of no benefit in patients (n=125) with near occlusion. The effect of surgery in this group was highly significantly different from that in patients with 70% to 99% stenosis without near occlusion (P=0.002). Surgery was harmful in patients with <30% stenosis (n=1321, P=0.007) and of no benefit in patients with 30% to 49% stenosis (n=478, P=0.6). CONCLUSIONS: Results of the ECST and NASCET were consistent when analyzed in the same way. In ECST, surgery was highly beneficial for 70% to 99% stenosis and moderately beneficial for 50% to 69% stenosis. However, contrary to clinical recommendations and current practice, surgery was of little benefit in patients with carotid near occlusion.

Aged↗
PubMed2004

Findings from the reanalysis of the NINDS tissue plasminogen activator for acute ischemic stroke treatment trial.

BACKGROUND AND PURPOSE: Following publication of concerns about the results of the National Institute of Neurological Disorders and Stroke (NINDS) intravenous tissue plasminogen activator (t-PA) in acute stroke treatment trial, NINDS commissioned an independent committee "to address whether there is concern that eligible stroke patients may not benefit from t-PA given according to the protocol used in the trials and, whether the subgroup imbalance (in baseline stroke severity) invalidates the entire trial." METHODS: The original NINDS trial data were reanalyzed to assess the t-PA treatment effect, the effect of the baseline imbalance in stroke severity between the treatment groups on the t-PA treatment effect, and whether subgroups of patients did not benefit from receiving t-PA. RESULTS: A clinically important and statistically significant benefit of t-PA therapy was identified despite subgroup imbalances in baseline stroke severity and an increased incidence of symptomatic intracerebral hemorrhage in t-PA treated patients. The adjusted t-PA to placebo odds ratio (OR) of a favorable outcome was 2.1 (95% CI, 1.5 to 2.9). Although these exploratory analyses found no statistical evidence that the t-PA treatment effect differed among patient subgroups, the study was not powered to detect subgroup treatment differences. CONCLUSIONS: These findings support the use of t-PA to treat patients with acute ischemic stroke within 3 hours of onset under the NINDS t-PA trial protocol. Health professionals should work collaboratively to develop guidelines to ensure appropriate use of t-PA in acute ischemic stroke patients.

Data Interpretation, Statistical↗