PubMed Health⌕ Search

Biomedical subjects

J Samuelson

Publications and source records attributed to J Samuelson.

66 records · Page 4Linked to original sources
PubMed1987

Safety and immunogenicity of Haemophilus influenzae type b polysaccharide-diphtheria toxoid conjugate vaccine (PRP-D) in infants.

Safety and immunogenicity of a Haemophilus influenzae type b polysaccharide-diphtheria toxoid conjugate vaccine (PRP-D) was evaluated in infants seven to 14 months of age. PRP-D (80% of subjects) or saline placebo (20%) was randomly and blindly administered (two doses separated by two months). Incidence of mild reactions lasting less than 48 hr did not differ significantly between the placebo and vaccine recipients. Preimmunization levels of antibody to PRP were less than or equal to 0.15 micrograms/ml in 97% of subjects. A twofold increase in antibody concentration occurred in 88% of subjects following the first dose and in 99% following the second dose of vaccine. No change occurred in placebo recipients. Mean level of antibody and percentage of subjects with levels of antibody greater than or equal to 1 microgram/ml after vaccination increased with increasing age. Responses were related to vaccine lot but not to sex, race, or geographic location. Two doses of PRP-D in infants seven months of age and older induced antibody levels equal to or greater than levels in infants 24 months of age given the polysaccharide alone.

Antibodies, Bacterial↗
PubMed1986

Persistence of antibody and response to booster dose of Haemophilus influenzae type b polysaccharide diphtheria toxoid conjugate vaccine in infants immunized at 9 to 15 months of age.

At approximately 2 years of age, 27 infants previously immunized at 9 to 15 months of age with two doses of polyribosylribitol phosphate-diphtheria toxoid conjugate vaccine (PRP-D) and 23 infants immunized with polyribosylribitol phosphate (PRP) vaccine were given a single injection of PRP-D. Pre- and post-immunization sera were obtained. No serious local or systemic reactions were observed. The PRP-D recipients had a geometric mean anti-PRP antibody level of 4.8 micrograms/ml 1 month after the second primary injection, retained 1.2 microgram/ml 1 year later, and had a level of 71 micrograms/ml after the booster immunization. In contrast, PRP recipients had a geometric mean level of 0.083 microgram/ml 1 month after the second primary injection, retained 0.042 microgram/ml 1 year later, and after a single dose of PRP-D at approximately 2 years of age had a geometric mean level of 8.6 micrograms/ml. The significantly higher antibody response in the prior PRP-D recipients suggests the recall of immunologic memory induced by the PRP-D vaccine.

Antibodies, Bacterial↗
PubMed1985

Antibody levels achieved in infants by course of Haemophilus influenzae type B polysaccharide/diphtheria toxoid conjugate vaccine.

A Haemophilus influenzae type b (Hib) capsular polysaccharide (polyribosylribitol phosphate, PRP)/diphtheria toxoid (D) conjugate vaccine was given to 71 infants. The level of anti-PRP antibody believed to predict long-term protection, 1.0 microgram/ml, was reached in 50% of the infants who were vaccinated at 3, 5, and 7 months, and in 57% of the infants who received PRP-D at 7 and 9 months of age. A lower level of antibody, 0.15 micrograms/ml, which has been associated with protection at the time of assay, was reached in 92% and 87% of the two groups. Thus, the seroresponse was dependent upon both the frequency of immunisation and age of the infant. Comparison of these results with previous experience with PRP immunisation in Finland showed that PRP-D induced substantial antibody rises at an earlier age than did PRP.

Age Factors↗
PubMed1985

Response of preterm infants to diphtheria-tetanus-pertussis immunizations.

To establish guidelines for the routine use of diphtheria, tetanus, and pertussis (DTP) vaccine in preterm infants, we quantitated antibody responses of preterm infants to DTP and determined the nature and extent of side effects. Twenty-five preterm infants were immunized with 0.5 ml DTP vaccine at routine intervals. Term infants served as controls. Immediately before each immunization and 2 months after the third, DTP-specific antibodies were quantitated. Clinical side effects were determined by parental report. After the second immunization, 100% of preterm infants had evidence of specific antibody production against diphtheria, tetanus, and pertussis. The incidence of side effects was low, but irritability was significantly more common in preterm infants after the second immunization. These observations suggest that the initiation of primary immunization with DTP in preterm infants need not be delayed beyond 2 months of age.

Diphtheria Toxoid↗
PubMed1984

Immune response of adults to sequential influenza vaccination.

Annual immunization against influenza is recommended for numerous individuals, but the antibody response to sequential vaccination has not been well characterized. Levels of hemagglutination-inhibition antibody were measured in adults given either two or three doses of trivalent influenza vaccine at six-month intervals. A significant rise in the number of individuals with antibody titers of greater than or equal to 40 was seen for all three antigens only after initial vaccination. Repeated vaccination was necessary to maintain adequate antibody levels only to the A/Brazil (H1N1) antigen; it did not significantly affect the proportions of individuals with protective levels of antibody to either the A/Bangkok (H3N2) or the B/Singapore 222/79 antigens. These findings do not support the current recommendation for annual immunization when the vaccine formulation has not changed.

Adolescent↗
PubMed1984

A method of processing first-trimester chorionic villous biopsies for cytogenetic analysis.

Chorionic villous biopsy is emerging as a technique for obtaining fetal cells for prenatal diagnosis in the first trimester of pregnancy. Chromosome analysis has been performed on small villous biopsies using either direct harvests of uncultured cells or after culturing villous tissue. Here, we describe a method where both techniques can be used simultaneously; from a single villous biopsy, GTG-banded chromosomes of improved morphology are obtained from direct preparations and from cultured villous cells.

Biopsy, Needle↗
PubMed1981

Cytologic studies for the diagnosis of pancreatic cancer.

Endoscopically obtained fluid from the ampulla of Vater was subjected to cytologic examination in 141 of 159 patients with suspected pancreatic disease, most of whom were undergoing endoscopic retrograde cholangiopancreatography (ERCP) examination. Of 26 patients with proven carcinoma of the pancreas, cannulation of the ampulla was successful in 22, and in 12 of these the cytology was positive (54%). Several technical considerations are suggested to increase the yield of positive cytology. They include aspiration of 3 ml or greater, deep insertion of the cannula, collection of pure pancreatic juice, high suction, and use of a fine intraductal rasp. The diagnostic sensitivity of ERCP alone was 73% in patients with cancer, but in combination with cytology it increased to 85%. The combined evaluation yielded 100% accuracy in 22 cases of cancer in which the ampulla was successfully cannulated. In 51 patients with chronic pancreatitis, and in 75 without proven pancreatic disease, the specificity of cytology was 98% and 97% respectively. The specificity of ERCP in chronic pancreatitis was 94%. Cytology is a useful adjunct to the ERCP examination in the diagnosis of pancreatic carcinoma.

Adenocarcinoma↗
PubMed1978

A serological assay for the detection of cell surface receptors of nerve growth factor.

When single-cell suspensions prepared from embryonic day 8 (E8) chick sensory ganglia are incubated with nerve growth factor (NGF), anti-NGF antiserum, and complement, an NGF-dependent cytotoxic kill of 20 (+/- 3)% of the ganglia cells is observed. This percentage is increased by a factor of two when only the neuronal cells are tested. No kill is observed on the nonneuronal cell population representing 50% of the ganglia dissociate. When E8 sensory ganglia cells are cultured in the presence of NGF following cytotoxic kill, the large, phase-bright NGF-reponsive neurons are missing from the culture. These results indicate that the cells recognized in the cytotoxicity assay have to carry NGF-binding sites of type I, which is the one with the higher affinity of the two types of NGF-binding sites (I and II) present on sensory ganglia cells. This conclusion is further supported by the following data: a) half maximal cytotoxicity is reached already at a concentration of NGF which is below the KD of binding site I; b) a washing step which removes all NGF bound to type II receptors while leaving a high percentage of type I receptors occupied has no effect on the percentage of ganglia cells killed. Using the cytotoxicity assay the presence of high-affinity binding sites of type I can be demonstrated on sensory ganglia cells from E8 chick embryos but not from E4 embryos and not on liver and heart cells from E8 embryos. Further, type I receptor-bearing cells were detectable in the brain using this assay. At E8, NGF receptors could be detected on cells of the forebrain and the tectum but not on brain stem cells. Cytotoxic kill of forebrain cells was found to be especially high at E8 and E9, and decreased by E10.

Animals↗
PubMedDate not supplied

Responses of Entamoeba invadens to heat shock and encystation are related.

An Entamoeba invadens gene encoding a homologue of BiP/GRP78, a 70-kDa heat shock protein or chaperonin was cloned. The predicted E. invadens BiP contained an ATP-binding site, a substrate-recognition domain, and a carboxy-terminal KDEL-peptide. Messenger RNAs of E. invadens for BiP, for a 70-kDa heat shock cognate, for a cyst wall glycoprotein (Jacob), and for chitinase were all induced by heat shock and by encystation medium. The presence of Jacob in heat-shocked amebae was confirmed by confocal microscopy and suggests that heat shock and encystation responses in E. invadens are related.

Adaptation, Biological↗