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Biomedical subjects

S Harris

Publications and source records attributed to S Harris.

At least 253 records · Page 14Linked to original sources
PubMed1989

Initial coronary occlusion improves tolerance to subsequent prolonged balloon inflations.

An acute coronary occlusion with severe ischemic signs during percutaneous transluminal coronary angioplasty was successfully treated with a long balloon inflation. Subsequent balloon inflations did not produce ischemic signs. Distal coronary occlusion pressure rose significantly during balloon inflations of more than 2 min. It is hypothesized that an initial ischemic occlusion may improve tolerance to prolonged coronary occlusions. The underlying mechanism may be that further coronary collateral circulation is recruited over time.

Angina Pectoris↗
PubMed1989

The molecular manipulation of milk composition.

The introduction of cloned genes into the mouse germ line is now routine. Although more difficult technically, gene transfer has been accomplished in farm animals and offers the potential for genetic improvement. In this regard, we have been investigating the use of transgenic animals as production vehicles for high value proteins in milk. We have shown that DNA sequences derived from the gene encoding sheep beta-lactoglobulin mediate efficient and specific expression in the mammary gland. A fusion gene comprising beta-lactoglobulin sequences and those encoding antihemophilic human factor IX has been constructed. This construct has been introduced into sheep; it is expressed in the mammary gland, and the corresponding protein is secreted into milk.

Animal Husbandry↗
PubMed1989

Carcinoma metastatic to the eye.

Cancer is a leading cause of death in America. Cancer to the eye is being diagnosed with increasing frequency. It is now considered the most common intraocular malignancy in adults. Although most ocular metastases do not require treatment, they have important prognostic implications for the patient's overall survival. Diagnostic errors leading to enucleation could be reduced if the incidence of metastatic tumors was always well considered. Presented here are two patients with metastatic tumors and a brief discussion of the nature of this ocular disease.

Adenocarcinoma↗
PubMed1988

Tubal function and surgery in chronic otitis media. A study on the predictive value of testing tubal function, Valsalva's manoeuvre and volume of ear spaces.

In 141 ears with central tympanic membrane (TM) perforation preoperative tubal studies as well as volume determination of the air-filled ear spaces was performed. Tubal patency was checked with Valsalva's manoeuvre and pressure equilibration function with Toynbee's test and aspiration-deflation tests respectively. At postoperative control 74.5% of the ears had intact movable TM (healed), 5.7% had intact but immovable or retracted TM and 19.8% had perforation (defect). There was no difference between the healed and defect ears regarding results in aspiration-deflation tests. A positive Valsalva's manoeuvre was significantly more frequent in the healed ears. Ears with a small air-filled volume and negative Valsalva's manoeuvre showed significantly lower healing rate than ears with positive Valsalva's manoeuvre and a large air-filled volume.

Adult↗
PubMed1988

Three-dimensional laser Doppler interferometric display of human tympanic membrane vibrations at two different frequencies and sound pressure levels.

The vibrational movements of the tympanic membrane of human in vitro specimens were studied by computerized laser Doppler interferometry. The entire surface of the vibrating tympanic membrane was scanned with the laser beam and all information was stored digitally making it possible to recreate the movements as in slow motion on the oscilloscope. Single phases of interest from the vibrational cycle were plotted as shown. The resonance patterns at 0.58 kHz and 3.11 kHz are compared and the effect of different sound pressure levels on the vibrational movement of the tympanic membrane demonstrated.

Doppler Effect↗
PubMed1988

Endonuclease cleavage pattern of cytomegalovirus DNA of strains isolated from congenitally infected infants with neurologic sequelae.

A prospective study of congenital cytomegalovirus infection in Malmö, Sweden, was performed from 1977 through 1985. The diagnosis was based on isolation of cytomegalovirus soon after birth. Congenital cytomegalovirus infection was identified in 76 infants, and as of September 1986 CNS symptoms have been experienced by nine of them. In at least seven of these infants, the disturbances can be referred to the cytomegalovirus infection. The strains from eight of the nine infants have been further studied by restriction endonuclease analysis of cytomegalovirus DNA. The cleavage patterns obtained with BamHI, EcoRI, and HindIII showed a unique pattern for each one of the eight strains. No common pattern could be associated with these eight strains in comparison with strains from postnatally infected children.

Child↗
PubMed1987

Paramyxovirus-like inclusions in two cases of pycnodysostosis.

We describe the biochemical and histological features of two related patients with pycnodysostosis. Examination of bone biopsies taken from both patients showed the presence of large nonfunctional osteoclasts which contained paramyxovirus-like inclusions similar in size and arrangement to those found in Paget's disease of bone. No radiographic, histologic or biochemical evidence for Paget's disease was found in either patient. The presence of osteoclast inclusions may not be specific for Paget's disease, therefore, and could be the result rather than the cause of abnormal osteoclast metabolism.

Adult↗
PubMed1987

Effect of human immunodeficiency virus (HIV) infection on chronic hepatitis B hepatic viral antigen display.

Immunofluorescent and immunoperoxidase monoclonal antibody-based techniques were used to demonstrate hepatitis B e antigen (HBeAg) and hepatitis B c antigen (HBcAg) display in the liver biopsy specimens of 45 chronic hepatitis B virus (HBV) carriers. Anti-human immunodeficiency virus (anti-HIV)-positive HBV carriers had many more HBe- and HBc-positive hepatocyte nuclei than anti-HIV-negative carriers (P less than 0.0003 and less than 0.02, respectively), and HBV-DNA levels were slightly, but not significantly, increased in the positive subjects. The number of HBe- and HBc-positive nuclei were positively correlated with serum HBV-DNA levels (P less than 0.05 comparing high serum HBV-DNA levels of greater than 2880 pg/ml and levels of 1-480 pg/ml), and were negatively correlated with disease activity (P less than 0.05 comparing those with severe chronic active hepatitis (CAH) and those with mild CAH and chronic persistent hepatitis (CPH]. These results indicate that male homosexual HBV carriers, positive for anti-HIV, may be immunosuppressed before there are clinical signs of immunodeficiency, and this allows an increased level of replication of at least one other virus (HBV).

Acquired Immunodeficiency Syndrome↗
PubMed1987

Frankia vesicles provide inducible and absolute oxygen protection for nitrogenase.

When Frankia HFPCcI3 was grown in culture at oxygen O(2) levels ranging from 2 to 70 kilopascals O(2), under nitrogen fixing conditions, nitrogenase activity adapted to ambient pO(2) and showed a marked optimum close to growth pO(2). Vesicles were thin walled at low pO(2) and very thick walled at high pO(2). Freeze fracture transmission electron microscopy confirmed that Frankia produces vesicles with outer walls thickened by multiple lipid-like monolayers, in proportion to ambient pO(2).

Journal Article↗
PubMed1987

Surgical treatment of cholesteatoma: a comparison of closed and open techniques in a follow-up of 164 ears.

In the Malmö community (230,000 inhabitants) 188 ears with cholesteatoma were operated on during 1975-1981. This number corresponds to an incidence of 12 cholesteatomas per 100,000 inhabitants a year. A detailed follow-up was possible in 164 ears. The primary operation was performed with an intact canal wall technique (CAT) in 148 ears and a radical operation in 40 ears. A planned second look was performed in 138 of the CAT ears and residual cholesteatoma was found in 41 or 30%, mainly in the epitympanic space. An initially good healing and hearing result was obtained in 71% but in the course of time several ears developed new retractions and a new mastoid cholesteatoma. The number of ears with perfect hearing tended to decrease with time, but about one-third of CAT ears remained intact with good hearing. The CAT technique is preferable in ears with a large mastoid air cell system and when the cholesteatoma is easily accessible by the approach. A planned second look should be performed including ossiculoplasty and obliteration of the antrum. In the remaining cases a radical operation including middle ear reconstruction and obliteration of the mastoid cavity is preferred.

Adolescent↗