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Biomedical subjects

B Huber

Publications and source records attributed to B Huber.

At least 55 records · Page 3Linked to original sources
PubMed1988

Synthesis of biologically active deletion mutants of human factor VIII:C.

The recent cloning and sequence analysis of human factor VIII:C (antihaemophilic factor) revealed a domain structure for the protein which can be presented as A1-A2-B-A3-C1-C2. In this report we describe the construction of two altered factor VIII:C cDNAs coding for molecules in which a part (amino acids 816 to 1598) or all of the B domain (amino acids 741 to 1689) was removed. In the latter mutant a new thrombin cleavage site has been created, which does not exist in wild-type factor VIII:C. The mutated cDNAs were cloned into eucaryotic expression vectors based on regulatory sequences of the virus SV40 and transfected into two different mammalian cell lines. Both truncated recombinant factor VIII:C molecules were secreted into the culture medium, showed full biological activity and could be activated by thrombin.

Amino Acid Sequence↗
PubMed1987

The effect on early plaque formation, gingivitis and salivary bacterial counts of mouthwashes containing hexetidine/zinc, aminefluoride/tin or chlorhexidine.

This study was designed to investigate the effectiveness of mouthwashes containing hexetidine/zinc (HZA) or tin (ASF) in inhibiting plaque formation and gingivitis in humans. 24 dental students and assistants participated in the study (latin square design) with 7-day test periods. They rinsed twice daily for 1 min with one of the following formulations: HZA = 750 ppm hexetidine/750 ppm zinc acetate, ASF = 100 ppm aminefluorid/310 ppm stannous fluoride, CHX = 0.1% chlorhexidine and M = negative control. Plaque accumulation was determined planimetrically and gravimetrically. Gingivitis was evaluated with the papillary bleeding index. Total colony forming units and S. mutans counts were estimated from saliva samples. The results showed that HZA and CHX almost completely inhibited plaque accumulation and gingivitis. ASF was less effective than HZA and CHX but still reduced plaque significantly compared to the negative control. Furthermore, CHX reduced salivary S. mutans counts.

Amines↗
PubMed1985

Identification and biochemical analysis of DNA replication-defective large T antigens from SV40-transformed cells.

Nine commonly studied Simian virus 40 (SV40)-transformed rodent cell lines were screened for tumor (T) antigens defective in SV40 DNA replication using a simple polyethylene glycol-mediated cell fusion assay. Each line contained a functional origin of SV40 DNA replication, as shown by fusion with Cos 1 cells. Fusion with uninfected monkey cells revealed that T antigens from two lines lacked detectable replicative activity, while T antigens from five other lines exhibited only very weak replicative activity. One line, and a tumor cell line derived from it, expressed T antigen with wild-type replication activity. Biochemical analysis of these proteins revealed defects in DNA binding activity and ATPase activity. One line expressed large T antigen defective in both activities. All of the lines contained complexes of T antigen with the cellular protein p53 and all of the T antigens exhibited nucleotide-binding activity. The results indicate that some of these lines may constitute a useful source of new replication-defective T antigens.

Adenosine Triphosphatases↗
PubMed1985

HSV- and chemical carcinogen-induced amplification of SV40 DNA sequences in transformed cells is cell-line-dependent.

Eleven simian virus 40-transformed cell lines from 5 different species were tested for their ability to amplify integrated simian virus 40 DNA upon infection with herpes simplex virus type I or treatment with various chemical carcinogens. Four cell lines were positive only for virus-induced gene amplification and two lines were positive for both carcinogen- and virus-induced gene amplification. Individual cell lines were assayed for the presence of an intact SV40 origin of replication, the expression of a functional SV40 T-antigen, and permissivity to herpes simplex virus replication. These parameters were found to be positive in all 6 amplification-competent cell lines. The ability of herpes simplex virus to amplify SV40 DNA sequences in transformed cells is greater than that of chemical carcinogens and can be suppressed by specific inhibitors of the herpes virus-encoded DNA polymerase.

Animals↗
PubMed1985

Evidence for defects in accessory and T cell subsets in mice expressing the xid defect.

Mice expressing the X-linked recessive CBA/N genetic defect xid lack a subpopulation of B cells which appears late in normal B cell ontogeny and is characterized by expression of the cell surface antigens Lyb3, Lyb5, and Lyb7. In adult mice with the xid defect, responses to Type 2 antigens such as TNP-ficoll are entirely absent and responses to Type 1 antigens such as TNP-LPS are somewhat reduced. Primary in vitro responses to the T dependent antigen sheep red blood cells (SRBC) are defective but secondary responses are normal. These and other findings have led to the hypothesis that one effect of the xid defect is the inability of a subset of B cells to respond to nonspecific signals from T cells or accessory cells. The cellular basis of the xid defect is not well understood. The simplest explanation is that it reflects a primary lesion in the development of a subpopulation of B cells responsible for the types of immune responses described above. An alternative notion is that the xid defect is expressed primarily in a non-B cell population (e.g., T cells or accessory cells) which are necessary for the development and/or function of this B cell subset. A direct approach to this problem depends on the availability of homogeneous populations of B cells, T cells, or accessory cells. Recently we have described a cloned dendritic cell, Den-1, which is a potent stimulator of some B and T cell responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

A comparison of the multi-test with the prick test and multi-test 2.

Allergy skin testing of infants and small children continues to be time-consuming and nerve-wracking. We hoped to have found the solution to these problems by using the multi-test (MT). The latter consists of an applicator with 8 heads, each head consisting of nine plastic needles on which the allergen solution rests. Thus eight allergens can be tested simultaneously. During routine control skin testing we compared MT with our usual method, the prick test (PT), amongst twenty patients. Twenty-seven per cent of the skin reactions differed by more than 1+. When we compared PT results with the previous PT, the correlation of 16% was better despite several years interval between tests, different persons carrying out the tests, and hyposensitization of patients. We adapted the MT system and produced a model, multi-test 2 (MT-2), which consists of eight sterile disposable needles on a stainless steel base. When we compared the MT-2 with PT, only 6% differed by more than 1+. Thus the MT-2 proves to be a useful alternative to the PT for those children, in whom the PT is too difficult to carry out.

Adolescent↗
PubMed1983

Meal timing as a Zeitgeber for skeletal deoxyribonucleic acid and collagen synthesis rhythms.

Meal timing protocols were used to probe the circadian regulation of DNA and protein synthesis in the rat tibia. Two groups of 4-week-old rats were entrained to 12-h light, 12-h dark cycles (light, 0800-2000 h; darkness, 2000-0800 h) for 4 weeks. One group was fed for 4 h at the onset of the light span (EL). The other group was fed for 4 h at the onset of the dark span (ED). Forty-eight hours before death, the rats were injected ip with 0.015 microCi/g BW [14C]proline [collagen and noncollagen protein (NCP) synthesis], and they received 0.25 microCi/g BW [3H] thymidine (DNA synthesis) 1 h before death. Groups of 10-12 rats were bled from the abdominal aorta at 4-h intervals under light ether anesthesia (1-2 min/rat) during 2 consecutive 24-h periods, and the tibias were then biopsied and frozen in liquid N2. Serum samples were analyzed for calcium, inorganic phosphorus, and immunoassayable levels of corticosterone (CS), PTH, and calcitonin. Epiphyseal cartilage and metaphyseal and diaphyseal bone were analyzed for DNA and acidic pepsin-digestible collagen. Chronograms indicated that DNA synthesis in cartilage and bone, along with serum CS, showed two approximately equal and positively correlated peaks, with the cycles for rats fed EL vs. ED being in approximate antiphase. The fit of a 12-h cosine curve was statistically significant in all cases (P less than 0.01). The acrophase peaks were: EL, 0800 and 2000 h; and ED, 1600 and 0400 h. These patterns were unrelated to those for NCP and collagen synthesis. EL and ED relationships for NCP synthesis were also antiphasal. A statistically significant circadian rhythm of collagen synthesis was detected in cartilage and bone of ED-fed rats (peak, 0800 h; nadir, 2400 h). In EL-fed rats, the 0800 h peak alone was muted. No consistent correlations were observed between serum calcium and phosphorus chronograms and those of cartilage and bone collagen and DNA synthesis. The results suggest that physiological alterations of CS in vivo serve to modulate cartilage and bone cell proliferation, but they do not seem to regulate the phasing of the net collagen synthetic rhythm.

Animals↗
PubMed1982

An unusual injury of the cervical spine caused by a fork lift.

A case of very unusual aetiology is reported. A severe traumatic injury of the cervical spine was associated with a suspended bilateral phrenic nerve paralysis, with limited sensory involvement, and weakness of the muscles of the right upper limb. The neurological status was otherwise normal, apart from slight weakness of the left upper limb. Artificial ventilation was necessary. Respiratory recovery was slow. The neural aetiology is discussed in relation to spinal cord and/or root involvement.

Accidents, Occupational↗
PubMed1981

The simplified oscillation method for measuring nasal resistance during provocation with allergens.

The simplified oscillation method was adapted to register nasal resistance because complicated and difficult procedures limited other known rhinomanometric tests. An initial study of thirty-nine subjects compared the effect of different-sized masks, revealing that the smaller the face mask, the smaller the capacitance and the higher the effective resistance. After an initial measurement, a second study group of twenty healthy and twenty pollinosis patients aged from 4 to 40 years underwent nasal provocation with grass pollen extract. Both study groups showed that despite high resistance, reactances were minor. This occurs because the nose acts as an aperture and an aperture has minimal reactances. With increasing concentrations of pollen extract, the nasal resistance of pollinosis subjects increased steadily, whereas the controls showed no change. Passive anterior rhinomanometry was measured for comparison and results contrasted sharply with the oscillation method: prior to provocation, initial values of control and pollinosis groups were already significantly different; after provocation, there was a statistically significant rise in resistance amongst the control as well as the pollinosis subjects. Further, the oscillation method for measuring nasal resistance proved to be simple, effective, and suitable for children.

Humans↗