Biomedical subjects

S Pollak

Publications and source records attributed to S Pollak.

At least 19 recordsLinked to original sources

PubMed1992

Attentional cues in chronic schizophrenia: abnormal disengagement of attention.

Posner's (1980) reaction time (RT) paradigm was used to examine the engagement and disengagement operations of visual selective attention in patients with schizophrenia. In the 1st experiment, 14 medicated, chronic schizophrenic subjects (diagnosed by criteria of the Diagnostic and Statistical Manual of Mental Disorders; American Psychiatric Association, 1987) and 15 age-matched normal control subjects made a speeded response to a target preceded by a valid, an invalid, or no cue. Control subjects showed the expected advantage and disadvantage in RT for valid and invalid cues, which suggests intact engagement and disengagement operations. For schizophrenic patients, valid cues also enhanced RT, but invalid cues did not slow RT. Similar results were found in the 2nd experiment. The failure of unpredictable, invalid cues to inhibit RT in chronic schizophrenia may be related to an abnormality in the disengagement operation of selective attention.

Adult↗

PubMed1992

Accessory nipples: any relationship to urinary tract malformation?

One hundred two infants and children age 3 days to 16.5 years, found to have accessory nipples (AN), were enrolled in this study. They were categorized by ethnic origin, sex, positive family history of AN, and number, site, and shape of AN, to determine factors for increased risk of anomalies of the urinary tract. Physical and ultrasound examinations of the abdomen did not reveal evidence of urinary tract malformation in any of the children. The results of this survey support the contentions that AN are not associated with urinary tract malformations, and that no further investigation is required in children with solitary AN.

Abnormalities, Multiple↗

PubMed1992

[Postmortem endoscopic diagnosis].

The use of endoscopical methods augments the macroscopical diagnosis in autopsies. Cavities and sinuses which are hardly accessible may be inspected and photographically documented as well without damage of the anatomical context. In terms of forensic autopsies the endoscopical technique is mostly recommended for the inspection of the fundus of the eye, the external auditory meatus up to the tympanic membrane, the naso- and laryngopharynx. Pathological and traumatical changes can be valued at once in situ. Forensic evidence of postmortal endoscopical findings is exemplified.

Adolescent↗

PubMed1992

[Effect of environmental temperature on the course of spontaneous postmortem pupillary changes (studies of the rabbit eye)].

The diameter of the pupils was measured in the bodies of rabbits under different ambient temperatures (2-4 degrees C, 10-12 degrees C, 18-20 degrees C, 28-30 degrees C). It was found that the pupils changed in three phases: Initial miosis, which set in within minutes after death, was followed by a mydriatic phase, which lasted several hours and was approximately synchronous with the post-mortem rigidity of the skeletal muscles. In the third phase the pupils slowly contracted in the course of several days. The higher the ambient temperature, the more marked was the dilatation of the pupils in the second phase. In contrast to this the reaction of the pupils was characterized by less pronounced changes in size and a longer duration of secondary mydriasis, when temperatures were low.

Animals↗

PubMed1992

[Agonal dog bite injuries].

A 57-year-old woman, who was unconscious due to apoplectic cerebral haemorrhage, was injured on the right thigh by dog bites while still alive. In addition to a soft-tissue defect of 10 x 9 x 3 cm (gnawing effect) there were numerous small single lesions in the form of slit-shaped skin cuts. The area around the wounds was discoloured by haematomata. The bite wounds were caused by the mongrel dogs living in the same household (2 parent animals and 6 puppies). The pattern of the injuries corresponded well to the anatomy of a dog's set of teeth.

Animals↗

PubMed1992

[Comparative studies of bullet entrance holes in trunk and extremity bones of predominantly spongious structure].

The size relation between the bullet calibre and the minimum diameter of the entrance hole in extracranial bones of predominantly spongy structure was systematically investigated. Test shots (cartridges .22 lr, 7.65 mm Brown. and 9 mm Parabellum) on bone specimens covered with soft tissue (coxal end of the femoral bone, ala ossis ilii, corpus sterni) showed the following results: The entrance holes in bone produced by solid-lead projectiles of calibre .22 showed a tendency towards larger diameters compared with the bullet (deviations at the proximal femur up to about 20%); full-jacketed bullets of calibre 7.65 mm and 9 mm mostly produced entrance holes which were smaller than the cross-section of the projectile (deviations at the sternum and os ilium up to about 12%). For perpendicular hits it was possible within one test-firing region to assign the minimum diameters of entry to one of the three calibres without any overlapping in the borderline area. The measurement results classified according to calibre and area of entry are indicated in diagrams.

Adult↗

PubMed1991

A method for assessing the reassembly of a multisubunit glycoprotein by western blotting.

The Western blot procedure has been adapted to detect the reassembly of a two-subunit glycoprotein, urinary human chorionic gonadotropin (hCG), directly on the nitrocellulose. This glycoprotein is composed of two nonidentical subunits, alpha and beta. A simple procedure using immunoblotting has been developed to detect reassembly of the monomers to dimer. Three monoclonal antibodies were required for the development of this method: A109, which binds the alpha subunit or hCG; B105, which binds the beta subunit or hCG; and B107, specific for the intact hCG dimer. The alpha subunit and beta subunit of hCG were each electrophoresed and transferred to nitrocellulose, and the transfer was then incubated with the appropriate complementary subunit; reassembly of the dimer was determined by the binding of the monoclonal antibody B107. Evidence that the reassembly occurs directly on the nitrocellulose comes from the fact that B107 immunoreactivity is detected at the molecular weight position of the subunit and not at the dimer molecular weight. A genetically expressed recombinant form of the alpha subunit was also tested for its ability to recombine with the opposite subunit to produce the dimer. The recombinant alpha subunit was determined to have additional carbohydrate which interfered with the binding of the beta subunit. N-Glycanase digestion of the recombinant alpha subunit produced a form which, when incubated with the beta subunit, did recombine on the nitrocellulose and could be recognized by B107.

Antibodies, Monoclonal↗

PubMed1991

Delayed cardiac rupture due to blunt chest trauma.

A 7-year-old boy fell from a 2.5-m height and suffered contusion of the thorax with hematoma in the soft tissues of the lateral chest wall. The rib cage itself remained intact. After 3 days, there was only local pressure sensitivity of the left hemithorax. On day 8 after the trauma, the child, who up to then had seemed to be in good health, suddenly died during lessons at school. Autopsy revealed a full-thickness rupture of the left ventricle with resultant cardiac tamponade. The macroscopic and histopathologic findings are presented and discussed.

Abdominal Injuries↗

PubMed1991

[Morphologic and morphometric aspects of contusion ring ("abrasion seam") of gunshot wounds].

Test shots (cartridges .22 lr and 9 mm Parabellum) were fired on skin preparations taken from the lumbar region. As anticipated, with caliber .22 the outer diameter and the area of the abrasion ring were smaller than with the 9 mm caliber. This was true of both orthograde and inclined angle shots. In the case of vertical projectile impact, the outer diameter of the epidermis-free area was either smaller or only slightly larger than the cross-section of the projectile. The area of the abrasion ring exceeded the area of the entrance hole in the proportion of 3:1 (.22 lr) and 2.45:1 (9 mm Para), respectively. The epidermis bordering immediately on the abrasion ring was lifted off, with irregular and torn-in edges. Progressive drying up of this border zone simulated a time-dependent increase of the abrasion ring. If the bullet penetrated at an oblique angle, the eccentrically enlarged drying-up collar (on the side from which the bullet came) showed a tongue-shaped area of unaffected epidermis with an intact stratum corneum. This phenomenon can be explained by the wound-ballistic behaviour of the skin in inclined angle shots. Skin covered with a layer of water showed no abrasion collar around the entrance hole.

Firearms↗

PubMed1991

[Pattern of experimentally-induced subcutaneous hematoma].

Healthy persons were each injected with 1 ml autoblood into the subcutis of the inner upper arm. Following this, different objects were applied to each haematoma area and kept pressed on the area for one hour by means of a sphygmomanometer cuff (30 mm Hg), to establish whether this would lead to secondary shape or pattern changes of the haematoma. When the haematomata were compressed by shaped objects, there developed patterned blanched areas or intensity differences, respectively, becoming more marked in the course of several days in the living experimental persons. In corpses greater quantities of blood were injected (10 ml) and higher contact pressures applied (up to 180 mm Hg). In some cases a markedly delimited imprint reflecting the configuration of the object became discernible already one hour post injectionem.

Adult↗

PubMed1991

[Morphometric findings of stab wounds].

Stabbing experiments with a single-edged blade on skin preparations taken from three regions of the body (anterior chest wall, abdominal walls, lumbar region) showed the following results: The most gaping stab wounds were found, as anticipated, if the blade was stabbed perpendicular to Langer's lines. If the blade entered parallel to these lines, which depend on the pattern of cutaneous fibres, narrow slit-like wounds were produced; the dimensions of wounds from stabs at an angle of 45 degrees were between the two extreme patterns. The length of the skin wounds in orthograde stabbing (without cutting movement) was greater in the abdominal region than in the chest and lumbar regions, but never reached the full width of the penetrated blade, not even after restoration (by approximating the edges of a gaping wound).

Humans↗

PubMed1991

[Spontaneous gallbladder rupture caused by "variceal hemorrhage"--an unusual complication of portal vein thrombosis].

The post-mortem examination of a 50-year-old man, who had died suddenly, revealed a massive intraabdominal hemorrhage resulting from the rupture of an ectatic vein situated in the gall-bladder bed; the consecutive hemorrhage first led to a hematoma of the gall-bladder and secondarily to a tear of its wall. A macronodular alcoholic cirrhosis of the liver had caused a thrombosis in the hilar branches of the portal vein. The link in the pathogenesis between this portal vein occlusion and the venous bleeding into the gall-bladder is to be seen in a collateral circulation between the portal and caval system via the vena cystica. This unusual portal bypass using the veins of the gall-bladder extends the wide scope concerning the differential diagnosis of sudden natural death.

Gallbladder↗

PubMed1991

[Significance of intraosseous skull cap hematoma for reconstruction of skull injuries].

Diaphanoscopic postmortal examination of blunt impact injuries to the head sometimes revealed non-diaphanous regions deriving from intraossary haematomata. Precise delimitation of these haematomata in the diploe from haematopoietic foci or neoplastic lesions was possible by means of histological examination. The location of the intraossary skull-cap haematomata coincided with corresponding injuries of the scalp as contusions and lacerations; they were often accompanied by fissural bone lesions and linear fractures. As such a diploetic haemorrhage represents a facultative counterpart of scalp contusion, its demonstration allows conclusions to be drawn as to the area of the impact, even if, owing to postmortal changes, the scalp is no longer assessable.

Adult↗

PubMed1990

[Use of rectal temperature-time of death nomograms at the scene of death].

The application of the rectal temperature time of death nomogram at the scene of death by 11 authors from 6 lego-medical institutes resulted in a standard deviation of the differences between nomographic and real death time of +/- 1.3 h in 46 cases (group I) with met requirements and clearly defined points of contact, nevertheless, including 9 cases with a more progressive cooling (0.5 greater than Q greater than or equal to 0.2). In cases with a real death time of more than 4h (N = 26) the standard deviation was +/- 1.0 hours corresponding to permissible variation of 95% of +/- 2.0 hours. Consequently, the permissible variation of 95% was much smaller than that suggested by the nomogram. The nomographic death time interval did not agree with the real one in 5 cases out of additional 30 cases with recognizably unsure points of contact (group II).

Body Temperature Regulation↗

PubMed1990

High resolution high performance liquid chromatography fingerprinting of purified human chorionic gonadotropin demonstrates that oxidation is a cause of hormone heterogeneity.

To characterize the structures of the various forms of hCG and its immunologically related fragments measured in blood, urine, and tissue culture media, we developed a highly sensitive HPLC tryptic fingerprinting system that can characterize as little as 15 micrograms of material. Standard preparations of the subunits of hCG purified from pregnancy urine were found to exhibit heterogeneity on reverse phase HPLC chromatography, complicating efforts to characterize such forms of hCG. The same type of chromatographic heterogeneity was observed when the hormone was reduced and S-carboxymethylated (RCM) and its RCM subunits separated on HPLC. One major and one minor peak were observed in the alpha- and beta-subunits from both native and RCM hormone, with a ratio of between 5:1 and 10:1. Development and application of a high resolution, semimicrobore HPLC fingerprint technique used together with an examination of selected peptides by amino acid sequencing and mass spectrometry defined the differences between these forms as oxidation. Using each of the isolated RCM subunit's major and minor HPLC peaks, the oxidation was shown to be reversible and probably due to interconversion of methionine with its sulfoxide form.

Chorionic Gonadotropin↗

PubMed1990

[Injury patterns and roentgen findings in gunshot wounds with rare flint ammunition].

Smoothbore shotgun barrels can fire cartridges with common pellet loads as well as shotgun slugs and rubber bullets. Other than conventional shot, the cylindrical Brenneke-type rifled shotgun slugs sometimes cause perforating wounds. The shotgun ammunition for use in self-defence can have a single projectile or several rubber pellets. Where the propellant is black powder, short range shots will probably leave searing marks and intensive soot deposits. Fired at close range, rubber bullets can penetrate through the skin into the body, fired at greater distance they cause contusions. A case of homicide (repeated firing with a 12-ga. pump gun) is used to present and discuss the injury patterns and X-ray findings after impact of Brenneke-type slugs and rubber bullets as well as of "classical" shot pellets.

Firearms↗

PubMed1989

Crystallization and characterization of human chorionic gonadotropin in chemically deglycosylated and enzymatically desialylated states.

Crystals suitable for X-ray diffraction studies at moderate resolution have been grown from two forms of human chorionic gonadotropin (hCG): HF-treated hCG and neuraminidase-treated hCG. The enzymatically desialylated form of hCG produced crystals that diffract to 2.8 A as compared to the HF-treated hCG crystals that diffract to 3.0 A. Although it was assumed that the high and heterogeneous carbohydrate content of the glycoprotein hormones inhibited their crystallization, this report suggests that it is the negatively charged surface sugars and neither the total carbohydrate content nor its heterogeneity which interferes with crystal formation. Chemical deglycosylation resulted in significantly increased protein degradation during crystal growth. Such peptide bond cleavages were observed to a much lesser extent in the crystals grown from neuraminidase-digested hCG. Sequence analysis of the HF-treated hCG crystals suggested that up to 45% of the molecules within the crystal had an acid-labile peptide bond cleaved. In contrast, the neuraminidase-treated hCG exhibited less than 9% of this type of cleavage. The increase in heterogeneity of the polypeptide chains within both crystals over that existent in the starting proteins was apparently due to changes occurring during crystal growth. The manner in which hCG was treated prior to crystallization was found to be a very important factor in the extent of peptide bond cleavages occurring during crystal growth. HF treatment of glycoproteins may render glycoproteins more susceptible to peptide bond cleavages during crystal growth.

Amino Acid Sequence↗

PubMed1989

[The high autopsy rate in Vienna].

In 1983 34% of all persons who died in the Republic of Austria were autopsied. We examined the frequency of postmortem examinations in the capital city, Vienna, between 1983 and 1987 in view of this high overall autopsy rate. The annual autopsy rate in all 9 pathology institutes and the department of legal medicine of the University of Vienna was on average 51 to 53%. There was a slight statistically verifiable decline in 1987. The reason for this high necropsy rate is that Austrian law permits the autopsies without the consent of next of kin if it appears indicated for medical, scientific or educational reasons; further more the fact, that the chairman of the department is at the same time the coroner for the hospital. A high autopsy rate is necessary to maintain a high standard of diagnostic accuracy even in modern medicine. The diagnoses were inaccurate or incomplete in 15% of all cases. The high autopsy rate is the basis for extremely accurate mortality and morbidity statistics and provides the basis for long range public health planning. Medical students develop an insight in disease patterns, which cannot be gained in any other way. The pathology departments of Vienna introduce a new city-wide computer-supported diagnostic file system, which will provide a baseline for comparative scientific studies.

Austria↗