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Biomedical subjects

A Palva

Publications and source records attributed to A Palva.

119 records · Page 7Linked to original sources

Recurrent meningitis due to pneumococci and non-typable Haemophilus influenzae in a child with a Mondini malformation.

An eight-year-old boy with a congenital inner ear malformation and recurrent otitis media had three episodes of bacteriologically confirmed meningitis within seven months. The first episode was caused by pneumococci, the other two by non-typable Haemophilus influenzae. All episodes were characterized by an abrupt onset. The CSF cultures were positive within 0.5 to 12 hours after the onset of symptoms. Despite misleading laboratory studies, surgical exploration revealed a CSF fistula associated to the inner ear anomaly. No further episodes occurred after the fistula was closed. Careful roentgenographic evaluation, including recently introduced special computed tomography (CT) methods, is indicated in recurrent meningitis. In addition, such evaluations should be considered even after the first episode, when special clinical features suggest a CSF fistula. Such features include an extremely rapid onset and detection of common non-invasive bacteria as causative agents, as illustrated by the present case.

Ampicillin↗

Sandwich hybridization as a convenient method for the detection of nucleic acids in crude samples.

A method based on three-DNA-component, sandwich hybridization has been designed for the detection and quantitation of nucleic acids in crude samples using adenovirus DNA as a model. Two non-overlapping restriction fragments of adenovirus type 2 (Ad2) DNA were cloned into two vectors, the pBR322 plasmid and M13 phage. The recombinant plasmid DNA was immobilized onto nitrocellulose filters and the single-stranded recombinant phage DNA was labeled with 125I and used as a probe. When these two reagents were incubated under annealing conditions no radioactivity became filter-bound; only if denatured adenovirus DNA was added as the third reagent, it mediated the attachment of the radioactive probe to the filters. Hybridization efficiency was shown to be dependent on both the filter and probe DNA concentrations and on the hybridization conditions. When standardized, the assay is quantitative, and under the conditions used 0.2 ng of adenovirus DNA (8 X 10(-6) pmol) could be detected by an overnight incubation. The test is suitable for crude samples, e.g., solubilized cell extracts, without any purification steps. Less than 100 cells infected with Ad2 can be detected, implying that the assay could be applicable to virus diagnostics.

Adenoviruses, Human↗

The secretory S complex in Bacillus subtilis is identified as pyruvate dehydrogenase.

We have cloned the operon for the Bacillus subtilis S complex, which has been suggested to be a component of the protein secretion machinery. The S-complex operon was found to encode 4 proteins, which were identified as subunits of pyruvate dehydrogenase (PDH). The Staphylococcus aureus membrane-bound ribosome protein (MBRP) complex has been considered to be a counterpart of the B. subtilis S complex. Here, we sequenced a fragment of the MBRP operon encoding the C-terminal part of E1 beta, the entire E2 and the N-terminal part of the E3 subunit of PDH, thus conclusively confirming the PDH identity of the MBRP complex as well. It appeared unlikely that PDH could be a primary component in protein secretion, thus disproving the previous hypothesis of the role of the S complex. However, attachment of the S complex (PDH) to the membrane and ribosomes may produce a biologically significant interaction.

Bacillus subtilis↗

Mucosal histochemistry in secretory otitis.

Mucosal biopsies were taken from 20 ears with secretory otitis media (glue ear) and histochemical stainings were made for comparison with data obtained from biochemical analysis of the fluids. Acid phosphatase, lactate dehydrogenase (LD), and malate dehydrogenase (MD), the activity of which in the ear fluids was 20 to 30 times higher than in serum, were found to appear as strong precipitates in the middle ear epithelium, particularly in the top layer. Alkaline phosphatase activity was only exceptionally seen in the epithelium but appeared in the capillaries and histiocytes. Nonspecific esterase appeared irregularly in the epithelium and regularly in histiocytes. The latter two had lower activities in ear fluids than in serum. Epithelial secretory cells and subepithelial glands and cysts showed strong alcian blue (AB)-positive staining. Positive material appeared also in the cytoplasm of the epithelial cells and in the intercellular substance. Distinct PAS-positive staining appeared in the columnar epithelium and particularly in the free mucus on top of the epithelium but was less promounced in the glandular structures and absent from the cysts.

Acid Phosphatase↗

Undistorted and filtered speech audiometry in children with normal hearing.

Undistorted and filtered speech tests were carried out in 140 test subjects with normal hearing acuity ranging in age from 4 to 19 years. Routine adult word lists were used in all tests. The intelligibility of undistorted speech rose markedly in the age groups from 4 to 9 years and correspondingly in the filtered speech test up to 11 years, taking the group 16-19 years as basis of reference. According to these results a speech discrimination test can be made in childhood with the same methods as in adults, if the norms are taken into account. In the filtered speech test the binaural test result and the monaural discrimination ability of the left ear were significantly better than the monaural test results for the right ear up to the age of 12-13 years.

Acoustic Stimulation↗

The role of the binaural test in filtered speech audiometry.

The value of the binaural resynthesis test administered according to Matzker's principle can be estimated only when a comparable monaural test can be used as a control. The most common positive finding in the filtered speech test is asymmetrical discrimination. Both parts of the message delivered to either ear must therefore have the same intelligibility in normal material. Binaural intelligibility is highly resistant to degenerative changes in the auditory system, for example. Positive findings in the binaural test are encountered frequently in brain stem lesions with vascular or traumatic aetiology.

Adolescent↗

Recruitment in conduction deafness. Observations using a midline loudness balance test.

A midline loudness balance test was made in 10 normal ears with blocked ear canals and in 104 conductively deaf ears with loss not exceeding 45 dB. The test was made by giving the tones simultaneously in the ears at 10, 60 and 80 dB sensation levels for 500 and 2 000 Hz. In the normal group the midline balance method indicated no reduction from the threshold differences at any of the three levels whereas significant reductions occurred in all groups of conduction deafness. The occurrence of true partial recruitment in conduction deafness demonstrated by ABLB (Fowler's) test was attributed to altered middle ear mechanics, loud tones stimulating the inner ear relatively more effectively than tones near the threshold level. The midline balance method is more closely dependent upon bone conducted sounds and on the altered relative movements of the labyrinthine windows.

Audiometry↗

Immunological defects in children with chronic otitis media.

A total of 59 children with chronic otitis media were examined for possible immunological defects by determination of serum gammaglobulin and immunoglobulins IgG, IgA and IgM, and by a tuberculin test, and additionally by noting any lymphopenia. Some divergence from normal values was found in 38 patients (64%). 14 children (24%) showed pathologically low immunoglobulin levels and 7 (12%) even a subtotal absence of one of the immunoglobulin fractions. 8 of the cases (14%) also showed a reduction of gammaglobulin level. In 20 children (34%), the level of one or more of the three major Ig classes was elevated. All except one became clinically normal within a few years, showing normal gamma or immunoglobulin levels when tested. The tuberculin test was positive in all patients. The length and course of the disease in these cases was similar to that in patients with normal test values. Gammaglobulin therapy did not have any beneficail effect. Consequently, it is concluded that although humoral immunological defects may be one aetiological factor, they do not play any major role in the course of chronic otitis media in children.

Adolescent↗

Surgical treatment of Meniere's disease.

Results are reported of the effect ov various surgical methods on vertigo in Meniere's disease. Minor preocedures like sacculotomy or application of NaCl crystals in the round window may effect a cure, but often results in deaf ears. Vestibular nerve section seems to offer the best of vertigo, while generally still preserving residual hearing.

Adult↗

Otosclerosis surgery.

Results of otosclerosis surgery using the stapes footplate removal with various types of reconstruction are reported in 456 ears (360 patients). Primary success was obtained in around 95% while 83% retained their improvement over the years. The posterior crus on fascia has become the preferred method because of its stability and relative lack of inner ear complications. Inner ear damage is mostly due to perilymph fistulae, which should be promptly recognized and repaired, since revision after the ear has become deaf does not restore hearing. Some late inner ear losses may be due to reactions to foreign material introduced with the graft. Bilateral operations should not be done if the first operation was difficult or caused vertigo for several days.

Acoustic Stimulation↗