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Biomedical subjects

D W Freeman

Publications and source records attributed to D W Freeman.

At least 19 recordsLinked to original sources
PubMed2000

Cross-reactive idiotypy in cerebrospinal fluid immunoglobulins in multiple sclerosis.

The presence of oligoclonal bands in cerebrospinal fluid (CSF) in multiple sclerosis (MS) indicates a restricted heterogeneity of immunoglobulin (Ig). The portion of myelin basic protein encompassing residues 80-96 contains epitopes frequently recognized by T and B cells of MS patients. To define further this restricted heterogeneity and to direct further efforts to identify an antigenic target of CSF oligoclonal bands, the presence of idiotope (Id)-bearing antibodies sharing an Id with a murine monoclonal antibody to myelin basic protein peptide 80-89 was examined in the CSF of MS patients. CSF samples from 57 patients with clinically definite MS and 45 patients with other neurological diseases were standardized for amount of IgG and analyzed by immunoblotting for detection of Id-bearing antibodies. Id-bearing Ig was detected in the CSF of 79% of MS patients and 16% of other neurological disease patients. Further statistical analysis revealed an 84% specificity, an 86% positive predictive value, and a 76% negative predictive value of the test. The probability that a positive screening result indicated MS was 81%. Thus, antibodies containing a cross-reactive Id are present preferentially in the CSF of patients with MS compared with those with other neurological diseases. An immune network that has limited V region gene usage likely exists in the CSF and central nervous system of patients with MS and may provide evidence about antigens relevant to the pathogenesis of MS.

Adolescent↗
PubMed1994

Monoclonal and polyclonal antibody responses to the myelin basic protein epitope present in human urine.

The myelin basic protein (MBP)-like material (MBPLM) in human urine is expressed in a cryptic epitope(s) present in MBP peptide 80-89 and absent or inaccessible in intact MBP. These features of urinary MBPLM have made it difficult to produce reagents for its further characterization. Using an immunogen of keyhole limpet hemocyanin conjugated to MBP peptide cys 74-89, polyclonal antiserum to urinary MBPLM was prepared. With the same immunogen and screening with urine, the product from one of over 1600 wells from the original fusion, produced monoclonal antibody (mAb) which could detect urinary MBPLM. By radioimmunoassay two rabbit polyclonal reagents recognized a cryptic epitope in MBP peptide 84-89 while the two mAbs recognized another cryptic epitope in MBP peptide 80-85. Both could be used for quantitation of MBPLM in urine. These and previous results indicate the presence of at least three epitopes, one noncryptic and two cryptic, in the decapeptide of MBP 80-89. Of the two cryptic epitopes, the one near the carboxyl-terminal is dominant to that in the amino-terminal portion. The detection of urinary MBPLM with reagents with two different specificities suggests the presence of two or more small MBP peptides in urine.

Amino Acid Sequence↗
PubMed1991

Evaluation of ventilating tubes and myringotomy in the treatment of recurrent or persistent otitis media.

In a prospective controlled study of the efficacy and sequelae of ventilating tubes, 44 children with bilateral recurrent acute otitis media (greater than 6 episodes/year) and 13 children with bilateral persistent middle ear effusion (greater than 3 months) received unilateral ventilating tube insertion in a randomly selected ear. The contralateral ears were randomized to receive either myringotomy alone or no surgery. Clinical, otoscopic, tympanometric and audiologic examinations were performed before the study and 2 to 4 weeks later, then at 3-month intervals for up to 2 years and at 36 months after surgical randomization. Medical therapy and antibiotic prophylaxis were used whenever indicated. While the ventilating tubes remained functional (mean duration, 10 months) the ears with a tube had significantly fewer episodes of otitis media than their contralateral ear (P less than 0.001; 95% confidence intervals -0.7, -1.7) and had more hearing improvement (P = 0.005; 95% confidence intervals, -5.9, -1.2). After tube extrusion there was a tendency for surgically treated ears to have more otitis and worse hearing, but not at a significant level. Tympanosclerosis, retraction and atrophy were more common in ears that received tubes. The majority of ears treated medically also improved. There is need for a more cautious and selective use of ventilating tubes.

Acoustic Impedance Tests↗
PubMed1988

Nitrogen metabolism in mature horses at varying levels of work.

Nitrogen metabolism was measured in five mature geldings performing varying levels of work that simulated race training. Following an initial maintenance period without forced exercise, workload was increased in succeeding 18-d periods by doubling the distance the horses were galloped in each period from period 2 through 4. A 4-d N balance experiment was conducted at the end of each 18-d period. The maximum distance galloped daily, which was in period 4, was repeated in period 5. Then, workloads were decreased through period 7. Nitrogen balance was determined in two additional periods, 8 and 9, while the geldings were at maintenance with no forced exercise. Geldings were fed diets containing similar protein-to-calorie ratios in all periods. Nitrogen retention increased (P less than .05) as workload increased from period 1 to period 3 and remained elevated throughout the rest of the experiment. Nitrogen retention did not (P greater than .05) decrease from highest values, observed at maximum workload during periods 4 and 5, until period 9, which was 34 d postexercise during a maintenance period. Nitrogen retention was higher (P less than .05) following training than before training.

Animals↗
PubMed1981

Antenatal prediction of women at increased risk for infants with low birth weight. A discriminant analysis of maternal characteristics known at 24 weeks.

Prenatal factors known to be associated with delivery of an infant with low birth weight (LBW) were studied in 165 women who were delivered of infants of 25,000 gm or less, as well as 154 women who were delivered of term infants with normal birth weights (greater than 2,500 gm). Data included information related to th clinical course of the pregnancy through 24 weeks' gestation. Of 25 characteristics measured prenatally, 10 variables were identified with indicated differences between the LBW and normal birth weight groups sufficient to make them suitable for a discriminant analysis. Following further analysis and attribute reduction, eight variables were selected as the final set of discriminating attributes. These are: maternal age, height, and weight, the patients's perception of her own parental treatment as a child, presence of uterine anomalies, bleeding during pregnancy, suspected multiple gestation, and number of previous pregnancies ending with a gestational age of 13 through 36 weeks. On the basis of coefficients derived for each of these variables, an equation was developed to derive a discriminant score for each patient. With the use of such equations, 73.5% of the known cases were correctly classified into groups with low and high birth weight. A similar high correct classification of cases was made when suspected multiple gestation was excluded as a variable.

Adolescent↗
PubMed1980

FHR variability and other heart rate observations during second stage labor.

Seventy-four fetal heart rate (FHR) records that were continued to vaginal delivery were selected for study from more than 2000 intrapartum FHR tracings. Thirty-six of the births were associated with neonatal depression and Apgar scores of 3 or less and/or 6 or less at 1 and 5 minutes, respectively; 38 patients exhibited normal Apgar scores (7 and 10 at 1 and 5 minutes, respectively). Twenty minutes of heart rate activity immediately prior to birth was the basis of analysis. All categories of loss of short-term beat-to-beat variability (BBV), both baseline and with decelerations, were observed more frequently in the group with low Apgar scores (P less than .001). In assessing variability, duration of observed loss of BBV appears to be an extremely critical factor. If BBV was lost 50% or less of observation time, a wide range of Apgar scores was observed. When more than 50% of the record showed loss of BBV, the number of depressed neonates was relatively high. Bradycardia (heart rate of less than 120 beats per minute) was present frequently in the records of the normal group. The number of variable decelerations and the amount of uterine activity were relatively high during second stage labor; a similar frequency was noted in both groups. Decelerations were nearly uniformly associated with uterine contractions in both groups, and accelerations were also noted in both groups. Uniform decelerations (late) were also present in both groups, with a greater frequency in the group with lower Apgar scores, but there were no distinguishing characteristics noted.

Apgar Score↗
PubMed1977

Hysteroscopic removal of intrauterine devices with missing filaments.

Ninety-one patients using intrauterine devices (IUD with nonvisible filaments on examination underwent hysterscopy for location and retrieval of the devices. These were among 320 patients who underwent hysterscopy for a variety of indications. All but 6 patients for whom additional surgery was planned were given local anesthesia. In 78 patients, the device was found within the uterine cavity and removed under hysterscopic control. In the remaining 13, no intrauterine device was observed. Six of these 13 patients had a translocated device which was removed either by laparoscopy or laparotomy. Hysteroscopy is proposed as a useful and effective method of diagnosis and management in ambulatory patients when the filaments of the IUD are absent.

Endoscopes↗
PubMed1977

Analysis of heart rate patterns preceding fetal death.

An analysis of fetal heart rate patterns preceding death is presented in 7 patients. The intrapartum deaths were not predictable on the basis of clinical evaluation. Predeath recording time varied from 11 minutes to 7.75 hours. An atypical deceleration pattern was observed in 3 patients terminally with associated loss of beat-to-beat variability. These occurred with uterine contractions, but had the characteristic appearance of variable decelerations (CC). This pattern was characterized by short contraction to deceleration intervals, and by large drops in the rate (62-102 beats/min). In 6 of the 7 patients, there was either absent (0-5 beats/min) or diminished (5-10 beats/min) beat-to-beat variability. In 1 the terminal recording showed an absolutely fixed rate with a progressive loss of beats and an increased amount of electrical noise.

Adolescent↗
PubMed1976

Maternal deaths due to spontaneous subarachnoid hemorrhage.

Spontaneous subarachnoid hemorrhage due to ruptured berry aneurysm and arteriovenous malformation accounted for 4.4 per cent of all maternal deaths in the State of Minnesota from 1950 to 1973. This catastrophic entiity ranked eighth in frequency regarding all causes of death and third among the nonobstetric causes. An analysis of the 37 deaths among 1,763,824 live births is presented. These 37 patients had delivered 96 infants and had 10 spontaneous abortions prior to current pregnancy. This suggest that pregnancy per se has no appreciable effect upon the occurrence of the hemorrhage. Five of these died in association with labor and delivery, or during a 1 day period-three during labor, one during vaginal delivery, and one only 1 hour postpartum. This is equivalent to 35 per week. On the other hand, 15 occurred during pregnancy (underlivered) (0.4 per week) and 17 during the first 3 months post partum (1.4 per week). These data seem to indicate that labor and delivery increase the risk of spontaneous subarachnoid hemorrhage. The neurologic state of these 37 patients was bad from the very onset of the hemorrhage. Rapid irreversible coma occurred in 34 (76 per cent). Of these 34, 24 (74 per cent) were dead within the first 24 hours and 32 (94 per cent) were dead within the first 4 days following the onset of the hemorrhage.

Adult↗
PubMed1975

The oxytocin challenge test in the management of high-risk pregnancies.

Appearance of a repetitive late deceleration pattern following oxytocin-induced uterine contractions in the prepartum patient may indicate fetal compromise, while absence of this finding may reflect fetal well-being. In this study, 72 patients at risk for intrauterine asphyxia underwent 81 satisfactory oxytocin challenge tests. Eight tests in seven patients were interpreted as positive; 72, as negative; and one, as suspicious. In 64 patients with negative tests, no fetal deaths or neonatal asphyxial depressions were observed. One patient developed intrapartum fetal distress with late decelerations 8 days after a negative test and was delivered by cesarean section. The positive test appears to correlate meaningfully with other clinical parameters reflecting intrauterine compromise.

Adolescent↗