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Biomedical subjects

B Hoff

Publications and source records attributed to B Hoff.

At least 19 recordsLinked to original sources
PubMed2004

Perinatal risk factors of adverse outcome in very preterm children: a role of initial treatment of respiratory insufficiency?

AIM: To investigate risk factors of adverse outcome in a cohort of very preterm children treated mainly with nasal continuous positive airway pressure (CPAP) during the neonatal course. METHODS: In Denmark, preterm children are treated with nasal CPAP as a first approach to respiratory support. A national prospective study of all infants with a birthweight below 1000 g or a gestational age below 28 wk born in 1994-1995 was initiated to evaluate this approach. Of the 269 surviving children 164 (61%) were not treated with mechanical ventilation in the neonatal period. A follow-up of the children at 5 y of age was conducted. Data from the neonatal period and the 5-y follow-up were analysed. RESULTS: In multivariate analyses including 250 children, a severely abnormal neonatal brain ultrasound scan was predictive of cerebral palsy (OR = 19.9, CI 95%: 6.1-64.8) and intellectual disability (OR = 6.2, CI 95%: 2.3-16.5). A high Clinical Risk Index for Babies (CRIB) score (OR = 2.4, CI 95%: 1.1-5.5) and chronic lung disease (OR = 2.8, CI 95%: 1.2-6.9) were predictive of intellectual disability. In univariate analyses mechanical ventilation was associated with cerebral palsy (OR=4.3, CI 95%: 1.7-10.8) and intellectual disability (OR = 2.2, CI 95%: 1.2-4.2), but the associations became insignificant in multivariate analyses including chronic lung disease and a severely abnormal ultrasound scan. CONCLUSION: The associations between neonatal risk factors and adverse outcome in our cohort were very similar to those found in other cohorts with another initial treatment of respiratory insufficiency. We found no significant adverse effects of mechanical ventilation beyond what could be explained by associations with chronic lung disease and IVH 3-4/PVL.

Cerebral Palsy↗
PubMed2004

Early nasal continuous positive airway pressure in a cohort of the smallest infants in Denmark: neurodevelopmental outcome at five years of age.

AIM: To evaluate neurodevelopmental outcome at age 5 y of age in a cohort of preterm children treated mainly with nasal continuous positive airway pressure (CPAP) in the neonatal period. METHODS: A national prospective observational study was conducted in Denmark which included all 269 surviving children with a birthweight below 1000 g or a gestational age below 28 wk born in Denmark in between 1994 and 1995. A total of 164 children (61%) had been treated with nasal CPAP only in the neonatal period. A reference group (n = 76) of term children was studied in parallel. RESULTS: Of the 269 surviving children, 252 (94%) were examined. Twenty-four children (10%) had cerebral palsy, and three children were blind. No case of hearing impairment was detected. Nineteen percent of the index children had an IQ score <-- 2 SD and 42% had an IQ score <-- 1 SD of the mean score of the reference group. CONCLUSIONS: The intellectual development of children in this cohort treated with early nasal CPAP did not suggest a higher proportion of adverse effects on the brain compared to the published follow-up studies of preterm children treated with mechanical ventilation. In our population-based cohort, however, the survival rate for infants below 25 wk of gestation was relatively low and this may indicate a limit for the use of early nasal CPAP.

Age Factors↗
PubMed2003

Treatment of extremely preterm infants: parents' attitudes.

AIM: To conduct a survey of the attitude towards treatment of extremely preterm infants by comparing the attitude towards life-saving treatment between a group of parents of extremely preterm children and parents in the general population. The importance the two groups of respondents assigned to parental preferences was also investigated. METHODS: A Danish national cohort of children born from 1994 to 1995 with a birthweight below 1000 g or a gestational age below 28 wk were assessed in a 5-y follow-up study including a reference group of children born at term. The parents of the children were given a sequence of case vignettes presenting different clinical situations, which formed part of a questionnaire. RESULTS: More than 80% of 222 possible index respondents and 76 possible reference respondents fulfilled the vignettes. Both groups of respondents were positive towards life-saving treatment of extremely preterm infants. The recommendations given by both groups were significantly influenced by the hypothetical child's risk of having a serious handicap and the parents' preferences. The results suggest that parents of extremely preterm children do not have a more conservative attitude towards life-saving treatment of extremely preterm infants than parents in the general population, and also support the view that parents' preferences should influence treatment decisions; although many believe that these should not be decisive. CONCLUSION: Compared to the general population, parents of children born extremely preterm did not express a more conservative attitude towards life-saving treatment of extremely preterm infants.

Adult↗
PubMed2001

Experimental design, analysis of variance and slide quality assessment in gene expression arrays.

A microarray experiment is a sequence of complicated molecular biology procedures relying on various laboratory tools, instrumentation and experimenter's skills. This paper discusses statistical models for distinguishing small changes in gene expression from the noise in the system. It describes methods for assigning statistical confidence to gene expression values derived from a single array slide. Some of the theory is discussed in the context of practical applications via software usage.

Algorithms↗
PubMed1999

Analyte comparisons between 2 clinical chemistry analyzers.

The purpose of this study was to assess agreement between a wet reagent and a dry reagent analyzer. Thirteen analytes (albumin, globulin, alkaline phosphatase, alanine aminotransferase, amylase, urea nitrogen, calcium, cholesterol, creatinine, glucose, potassium, total bilirubin, and total protein) for both canine and feline serum were evaluated. Concordance correlations, linear regression, and plots of difference against mean were used to analyze the data. Concordance correlations were excellent for 8 of 13 analytes (r > or = 0.90); the correlations for albumin, potassium, and calcium were clinically unreliable. The linear regression analysis revealed that several analytes had slopes significantly different from unity, which was likely related to methodological differences. Compared to the wet reagent analyzer, the dry reagent analyzer showed excellent agreement for alkaline phosphatase, alanine aminotransferase, amylase (feline), urea nitrogen, cholesterol, creatinine, glucose, total bilirubin (canine), and total protein. However, it showed only slight to substantial agreement for amylase (canine), calcium, albumin, potassium, and total bilirubin (feline).

Animals↗
PubMed1998

Retrospective study of toxic metal analyses requested at a veterinary diagnostic toxicology laboratory in Ontario (1990-1995).

During the 5-year period from January 1, 1990, to December 31, 1995, 887 diagnoses of metal toxicosis in domestic animals and wild birds were documented at the Veterinary Laboratory Services Branch of the Ontario Ministry of Agriculture, Food and Rural Affairs. Most of these cases involved cattle, sheep, and birds. Lead toxicosis was diagnosed in 399 cases, copper toxicosis in 387, zinc toxicosis in 49, mercury toxicosis in 44, iron toxicosis in 4, and selenium in 4 cases. Trends in species affected and sources of metals are discussed.

Animals↗
PubMed1997

Eperythrozoon ovis infection in a commercial flock of sheep.

A flock of sheep consisting of 60-70 winterfed ewes was examined. Blood was collected from approximately 30% of the sheep four times from 1991 to 1995. Eperythrozoon ovis (Ep. ovis) organisms were not detected in blood smears stained with Wright's stain in 1991 and 1993. In 1995, examination of blood smears stained with acridine orange revealed Ep. ovis organisms in 11 of 26 sheep, whereas examination of smears stained with Wright's stain revealed organisms in only one ewe with a high degree of infection. The prevalence of antibodies detected by IFAT varied from 58-100%. The antibody titres varied from 1:20 to 1:12,000. This investigation indicates that Ep. ovis infection once present in a flock of sheep may spread easily among the sheep, and that the infection seems to persist within the flock.

Animals↗
PubMed1996

Detection of HIV-1 DNA in cells and tissue by fluorescent in situ 5'-nuclease assay (FISNA).

The critical aspects of successful in situ amplification include fixation, permeabilization, amplification and detection. We address these aspects and present a novel detection scheme that eliminates hybridization following amplification. We use the 5'-nuclease activity of Taq polymerase to cleave in situ a 5'-reporter dye from an oligonucleotide probe which hybridizes to the target amplicon during amplification. The 5'-reporter dye is disassociated from the 3'-quenching dye and remains localized by charge interactions. In addition, we describe probe design constraints for 5'-nuclease assays both in solution and in situ. Using this technique, we show the sensitive and specific detection of HIV-1 DNA in cells lines and tissue from HIV-1-infected individuals.

5'-Nucleotidase↗
PubMed1990

Preparation of xenon-133 in a lipid emulsion for tissue perfusion studies.

A simple, inexpensive technique for concentrating xenon-133 in a medium suitable for intravenous use is reported. The method uses a 20% lipid emulsion, standard syringes, an oscillating motor, and xenon-133, which is available commercially. Typically, 43% of the xenon-133 combines with the lipid emulsion and remains stable for more than 24 hours in vitro.

Fat Emulsions, Intravenous↗
PubMed1985

An appraisal of bone marrow biopsy in assessment of sick dogs.

Dogs were classified into a number of disease categories according to hematological, cytological and serochemical changes. Aspiration and core bone marrow biopsies were examined in 128 dogs in the various disease categories and compared to marrow samples in 36 dogs which appeared clinically normal. Differential cell counts on bone marrow smears were examined in relation to the blood variables in all animals. Blood and bone marrow data (group means) were compared among the normal and disease groups. Anemia, responsive and poorly responsive was the most frequent blood abnormality. Most dogs in the thrombocytopenia group had increased numbers of megakaryocytes in the marrow but two dogs had a marked decrease. The frequency of serious alteration of marrow production of the erythroid, myeloid and megakaryocytic series was less than anticipated. Marrow hemopoiesis was not significantly compromised in dogs with lymphoma or in dogs with other types of cancer. Bone marrow examination was necessary for the diagnosis of myelofibrosis and pancytopenia and was very helpful in the groups with insufficient change in the blood to permit a definitive diagnosis to be made. The myeloid-erythroid ratio was a useful indicator of marrow response while the erythroid maturation index and the myeloid maturation index were useful for identification of altered patterns of maturation (ineffective hemopoiesis). The reticulocyte response in absolute numbers is the most efficient and clinically relevant measure of erythroid response.

Anemia↗
PubMed1980

Evaluation of outcomes of non-nurse midwives: matched comparisons with physicians.

The purpose of this study was to assess the practice of a group of non-nurse midwives by comparing the outcomes of their deliveries to the standard of hospital-based physicians. This was done by means of a matching procedure designed to equate the populations on major medical risk factors. The first phase of the study used all physicians and found major differences favoring the midwives. The second phase of the study used the least interventionist half of the physician group and found minimal differences between midwives at home and physicians in the hospital. It is suggested that excessive intervention is not without risk regardless of who does it.

California↗
PubMed1979

The "D circle": closed-circuit operation of the Bain circuit.

A method of converting a Mapleson D (Bain) circuit to closed-circuit operation is presented, utilizing a laboratory air pump and a Waters carbon dioxide absorber canister to recirculate exhaled gas. The elimination of carbon dioxide from the circuit was studied and found to be adequate. The circuit would allow the use of low fresh gas flows for the maintenance of anaesthesia without the danger of carbon dioxide rebreathing. We suggest that such a circuit could provide appropriate conditions of gas humidity and temperature for endotracheal anaesthesia, while realizing the advantage of a circulator in mask anaesthesia is possible. Further design considerations for a "D circle" breathing system for clinical use are discussed.

Anesthesiology↗
PubMed1979

Goodpasture's syndrome with normal renal function.

Two male patients with Goodpasture's syndrome manifesting as severe pulmonary hemorrhage with minimal renal abnormalities are described. Both patients had microscopic hematuria with normal renal function, and one had transient proteinuria. Renal glomerular histology was normal and electron microscopic findings revealed no electron-dense deposits, but immunofluorescence of immunoglobulin G (IgG) was positive in a linear fashion along glomerular capillary basement membranes in both patients. Pulmonary hemorrhage was arrested following prednisone therapy, and both patients have normal pulmonary and renal function at five and 13 months of follow-up. The literature on patients with Goodpasture's syndrome, pulmonary hemorrhage and normal renal function with minimal proteinuria is reviewed. It is suggested that a subset of patients with Goodpasture's syndrome have pulmonary hemorrhage as their major manifestation. Since prednisone seems to have an apparent beneficial effect on pulmonary hemorrhage, and relatively good prognosis, this diagnosis should be considered in patients with idiopathic pulmonary hemorrhage.

Adolescent↗