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Biomedical subjects

Y Hiss

Publications and source records attributed to Y Hiss.

At least 19 recordsLinked to original sources
PubMed2001

Focal lymphocytic infiltration in aging human palatal salivary glands: a comparative study with labial salivary glands.

Investigation of age-related prevalence of various types of focal lymphocytic infiltration (FLI) and degrees of histomorphologic changes was conducted on 120 biopsies of palatal and labial salivary glands (PSG and LSG, respectively) obtained from autopsy subjects free of salivary gland tumors/diseases. Biopsies were divided into young (<30 years, n=30), adult (30-60 years, n=45) and old (>60 years, n=45) age groups. A modified Chisholm & Mason grading system was used to record grades of FLI and a modified Greenspan et al. system was used to evaluate the severity of histomorphologic changes. The prevalence of FLI in PSG increased significantly from 10% in the young group to 46.6% in the old group (P=0.0012). No significant changes were found with aging in LSG. FLI was significantly more prevalent in the adult and old age groups in PSG as compared with LSG (P=0.015 and P=0.003, respectively). Both glands demonstrated significant histomorphologic changes among age groups (p<0.0001); however, these changes were significantly less common in the old age group in PSG as compared to LSG (P=0.003). In cases showing severe histomorphologic changes, FLI was not present. Therefore, FLI should not be considered as part of the deteriorating histomorphologic changes that are usually encountered in salivary glands with aging. The immunologic profile of these infiltrates should be further clarified to understand their role, both in physiologic and pathologic conditions.

Adult↗
PubMed2000

Evidence for the involvement of the hippocampus in the pathophysiology of schizophrenia.

The hippocampus, a medial temporal lobe structure, is often considered to play an important role in the pathophysiology of schizophrenia. Recent developments of neuroimaging and molecular postmortem techniques have significantly increased our ability to study the role of discrete brain regions in the pathophysiology of schizophrenia. This article describes animal models, structural, histological, molecular biology, and neuropsychological evidence for the involvement of the hippocampus in the pathophysiology of schizophrenia. The major findings in schizophrenic patients are decreased volumes, hypometabolism, and cytoarchitectural abnormalities which are more robust on the left hippocampus, as well as verbal memory impairment. It is yet to be determined whether these changes are neurodevelopmental or neurodegenerative in nature. Overall, these findings indicate that there are subtle changes in the hippocampus of schizophrenic patients. More comprehensive and focused hippocampal research in schizophrenia is required to elucidate the contribution of this intriguing brain structure to the pathophysiology of schizophrenia.

Animals↗
PubMed1998

Minimally invasive surgery for axillary dissection. Cadaveric feasibility study.

Axillary dissection is the major cause of morbidity in breast cancer and primary cutaneous melanoma of the extremity. In the present study, we examine the potential benefits and advantages of endoscopic axillary lymph node dissection over conventional surgery. Twenty endoscopic axillary dissections and 10 lymph node samplings were performed in 10 cadavers (four male, six female). A preperitoneal distention balloon (PDB) system was used to dissect the axilla. In four of the cadavers, the procedure was followed by open surgery. The axillary contents were examined for lymphatic tissue by a pathologist. The endoscopic technique offered easy access to the axilla and clear visualization of the axillary vein, as well as the long thoracic and thoracodorsal nerves. Results were comparable to those achieved with the classic surgical dissection. Endoscopy is feasible for axillary lymph node dissection and sampling in cases of breast cancer and primary cutaneous melanoma of the extremity. Further studies in patients are needed to reach definitive conclusions.

Axilla↗
PubMed1998

Retroperitoneal endoscopic lumbar sympathectomy with balloon dissection: experience with a cadaveric model.

The objective of this study was to determine the feasibility of retroperitoneal endoscopic lumbar sympathectomy with balloon dissection technique using a cadaveric model. Retroperitoneal endoscopic lumbar sympathectomy was performed on 10 cadavers. The procedure was combined with balloon dissection to provide easier visualization and more working space. The outcome was successful in eight cadavers. Average operating time was 40 min, and visualization was good. The only major technical problems were perforation of the peritoneum and air leak into the abdomen. It was concluded that retroperitoneal endoscopic lumbar sympathectomy with balloon dissection has the advantages of minimal invasiveness, clear visualization, and controlled blunt dissection. The use of a cadaveric model may improve the clinical learning curve.

Cadaver↗
PubMed1997

Seasonal variation of gonadotropins and gonadal steroids receptors in the human pineal gland.

Recently abnormal melatonin secretion was demonstrated in hypogonadal male patients which was normalized during testosterone administration. These results suggested that both gonadal steroids and gonadotropins may modulate melatonin secretion, probably by activating specific receptors in the pineal gland. We used immunohistochemistry to localize luteinizing hormone, follicle stimulating hormone, estrogen and androgen receptors in human pineal glands. Tissues were obtained at autopsy from 53 adult males (aged 19-94 years) over a period of 1 year. Positive staining for the four types of receptors was evident in all 53 specimens examined. The percent of positively stained cells revealed a significant seasonal variation of gonadotropin receptors with higher values in the winter than in the summer. Day-night difference was evident only for follicle stimulating hormone-receptors during the summer and winter, with higher values at night. Androgen receptors and estrogen receptors were present in all specimens but did not reveal day-night or seasonal variations. These data demonstrate the presence of gonadotropin and gonadal steroid receptors in the human pineal gland. Gonadotropin receptors exhibited seasonal variation with higher values in the winter.

Adult↗
PubMed1997

Immunohistochemical localization of gonadotropin and gonadal steroid receptors in human pineal glands.

Recently, we demonstrated that melatonin secretion was increased in male patients with GnRH deficiency and decreased to normal levels during testosterone treatment. These data suggested that gonadal steroids modulate melatonin secretion, probably by activating specific receptors in the pineal gland. We used immunohistochemistry to localize gonadotropin (LH and FSH) and gonadal steroid (androgens and estrogens) receptors in human pineal glands. Tissues were obtained at autopsy from 25 males, aged 19-87 yr, and five prepubertal children, aged 0.2-10 yr. Positive staining for all four types of receptors (LH, FSH, androgen, and estrogen) in the pineal parenchymal cells, pinealocytes, was evident in all 30 glands examined. Double staining revealed that nuclear receptors (androgen or estrogen) co-existed with cytoplasmatic receptors (LH or FSH) in the same cells. The results demonstrate the presence of gonadotropin and gonadal steroid receptors in human pinealocytes from infancy to old age.

Adult↗
PubMed1995

Laparoscopic vs conventional autopsy. A promising perspective.

OBJECTIVE: To analyze the sensitivity and specificity of laparoscopic autopsy when compared with the ulterior performance of conventional postmortem examination. DESIGN: Consecutive sampling, case-series study. SETTING: A general community referral medical center and the local institute of forensic medicine. PARTICIPANTS: A consecutive sample of 25 fresh cadavers (< 24 hours old) of victims of vehicle accidents, gunshot wounds, and in-hospital deaths. INTERVENTIONS: After insufflation with carbon dioxide, laparoscopy of the abdominal cavity and inspection of the retroperitoneal area was accomplished. Following, a conventional postmortem examination was performed and the findings of both procedures were recorded, compared, and analyzed. MAIN OUTCOME MEASURES: Prior to the beginning of the study, it was hypothesized that laparoscopic autopsy would reach an overall sensitivity and specificity of at least 85% and enable accurate inspection of the abdominal cavity and retroperitoneum in the search for the trauma-related cause of death in trauma victims or the cause of death for in-hospital patients. RESULTS: There was a 100% correlation of both procedures in all accidental cases. The sensitivity of laparoscopic autopsy was 93% for intra-abdominal lesions, with an overall sensitivity of 91%. For the retroperitoneal area, the sensitivity was 58%. The sensitivity for the retroperitoneum dropped, owing to an intrarenal tumor and an extraperitoneal rectal tear in the small sample of inhospital deaths. The specificity of laparoscopic autopsy reached 94%. CONCLUSIONS: Laparoscopic autopsy is accurate and easy to perform. It is highly sensitive for intra-abdominal abnormalities, especially in trauma victims. Laparoscopic autopsy is minimally invasive and not disfiguring, rendering it easier to accept among mourning families. It should be strongly considered when consent for a conventional autopsy is lacking.

Autopsy↗
PubMed1995

Thoracoscopy vs conventional autopsy of the thorax. A promising perspective.

OBJECTIVE: To analyze the sensitivity and specificity of thoracoscopic autopsy compared with that of conventional postmortem examination. DESIGN: Consecutive sampling, case-series study. SETTING: A general community referral center and the local Institute of Forensic Medicine. PARTICIPANTS: A consecutive sample of 20 fresh cadavers (less than 24 hours old), victims of motor vehicle crashes, gunshot wounds, in-hospital deaths. INTERVENTIONS: Introduction of the thoracoscope through the fourth or fifth intercostal space, anterior or midaxillary line. The pleural cavity and mediastinum were examined. Formal postmortem examination was then performed, and the findings of both procedures were recorded, compared, and analyzed. MAIN OUTCOME MEASURES: Prior to the beginning of the study, it was hypothesized that thoracoscopic autopsy would reach an overall sensitivity and specificity of at least 85% and enable accurate inspection of the thoracic cavity and mediastinum in search of trauma-related abnormalities in trauma victims or cause of death in in-hospital patients. RESULTS: There was an 85% correlation of both procedures in all cases. The sensitivity of thoracoscopic autopsy was 87% and overall specificity reached 72%. CONCLUSIONS: Thoracoscopic autopsy is accurate and easy to perform. It is highly sensitive, especially in deaths due to trauma and following thoracic surgery. Thoracoscopic autopsy is an important tool that allows the diagnosis of major chest abnormalities as well as ruling out postoperative catastrophe, information that is invaluable for the surgeon, as well as all the medical staff and families. Thoracoscopic postmortem examination should be offered to mourning families as a cosmetic and reliable option when informed consent for conventional autopsy is lacking.

Autopsy↗
PubMed1995

Intestinal anastomosis healing in rat: collagen concentration and histochemical characterization by Picrosirius red staining and polarizing microscopy.

The study was designed to characterize collagen fibers in the healing intestinal anastomosis of rat by examining collagen concentration and recording the polarization colors of the collagen fibers in Picrosirius red-stained tissue sections. No significant changes in collagen concentration expressed by hydroxyproline content were noted at the anastomotic site at various postoperative time points. In the normal intestine, the predominant polarization colors were in the yellow to yellow-orange range, signifying tightly packed, matured collagen. During the first postoperative week, collagen fibers at the anastomotic region exhibited mainly polarization colors in the green to green-yellow range, implying less packed intermediate collagen fibers. After 2 weeks, collagen fibers at the anastomotic region gradually reacquired their preoperative polarizing texture. These findings strongly suggest that the "quality" rather than the quantity of collagen fibers plays an important role in maintaining the tensile strength of the healing intestinal anastomosis.

Anastomosis, Surgical↗
PubMed1994

Age-related basement membrane thickening of the vocal cords in sudden infant death syndrome (SIDS).

Sudden infant death syndrome (SIDS) remains the leading cause of death in the Western world among infants between the ages of 1 month to 1 year. The diagnosis can only be established at autopsy, at which time no obvious or recognizable pathology is evident. A correlation between thickening of the basement membrane of the true vocal cords and the victim's age was observed in all 51 larynges examined, whereas no such finding was detected in 82 larynges of infants who died of other causes. Thus, the data support the authors' previous morphological results suggesting the use of basement membrane thickening as a marker of positive diagnosis of SIDS at autopsy. The possibility that an immune process may be associated with this syndrome merits further investigation and could prove to be of great importance.

Age Factors↗
PubMed1992

Fresh and frozen-thawed human sperm bind in a similar pattern to the zona pellucida in the hemizona assay.

This study evaluated the impact of sperm cryopreservation on sperm quality. The HZA was used to test the binding capacity of fresh as opposed to frozen-thawed sperm from 12 donors. Fresh and frozen-thawed sperm motility was 47% +/- 1.5% and 24% +/- 3.8% (mean +/- SE), respectively. However, the number of sperm cells attached to the hemizonae was 75 +/- 12.0 and 74 +/- 11.9, respectively. We conclude that cryopreservation results in a reduced number of motile sperm cells but does not adversely affect the ability of rescued sperm cells to bind to the ZP. The study also supports the use of frozen-thawed rather than fresh donor sperm for control in the HZA procedure.

Cryopreservation↗
PubMed1992

Fatal methemoglobinemia caused by inadvertent contamination of a laxative solution with sodium nitrite.

We describe two cases of fatal methemoglobinemia resulting from ingestion of laxative solution inadvertently contaminated with sodium nitrite. Postmortem toxicological examination revealed methemoglobin levels in excess of 75% in both patients--a level that is uniformly fatal. The laxative solution was found to contain sodium nitrite instead of sodium sulphate at a concentration of 15 g/l. The pathophysiology of methemoglobinemia and a review of other reported cases of toxic methemoglobinemia are presented. Marked cyanosis in the face of intact cardiorespiratory function should alert the physician to the possibility of toxic methemoglobinemia.

Aged↗
PubMed1991

Sudden unexpected death in persons less than 40 years of age.

This study retrospectively assesses the underlying causes of sudden unexpected death and the occurrence of prodromal symptoms in 162 subjects (aged 9 to 39 years) over a 10-year period (1976 to 1985). Underlying cardiac diseases accounted for sudden death in 73% and noncardiac causes in 15% of subjects. In 12% of subjects, the causes were unidentifiable. Myocarditis (22%), hypertrophic cardiomyopathy (22%) and conduction system abnormalities (13%) were the major causes in 32 subjects aged less than 20 years. Major causes of 46 deaths in subjects 20 to 29 years were atherosclerotic coronary artery disease (24%), myocarditis (22%) and hypertrophic cardiomyopathy (13%). The largest number of deaths in 84 subjects aged greater than or equal to 30 years was attributed to coronary artery disease (58%), followed by myocarditis (11%). Among noncardiac causes of sudden death, intracranial hemorrhage was the most frequent (5%), followed by infectious disease (4%). Prodromal symptoms were reported by 54% of subjects; most frequent were chest pain (25%) in subjects aged greater than or equal to 20 years, and dizziness (16%) in those aged less than 20. Sudden death, which occurred during routine daily activity in 49% and during sleep in 23% of subjects, was related to physical exercise in 23% and emotional upset in 6%. Sudden unexpected death in the young is still an unresolved medical problem. The early recognition of prodromal symptoms could be crucial in the prevention of sudden death, specifically when exercise-related.

Adult↗
PubMed1991

Connective tissue nevi collagens. Study with picrosirius red and polarizing microscopy.

Biopsy specimens of five connective tissue nevi were examined under crossed polars after staining with Picrosirius red. One biopsy specimen was from a solitary nevus, another from a Shagreen patch. The other three specimens were of erupted nevi. In all cases, thick (as well as thin) collagen fibers appeared green to yellow. In contrast, thick fibers of normal human dermis appeared orange to red. The findings indicate that the collagen of collagenous connective tissue nevi is less well packed than normal collagen. Examination of the polarization colors of Picrosirius red-stained sections is a useful procedure for diagnosing collagenous connective tissue nevi.

Adult↗
PubMed1989

Are the polarization colors of picrosirius red-stained collagen determined only by the diameter of the fibers?

Polarization colors of various purified collagens were studied in fibers of similar thickness. Three different soluble collagens of type I, insoluble collagen type I, lathyritic collagen type I, two p-N-collagens type I, pepsin extract collagen type II, two soluble collagens type III, p-N-collagen type III, and soluble collagen type V were submitted to a routine histopathologic procedure of fixation, preparation of 5-microns-thick sections, staining with Picrosirius red and examination under crossed polars. Polarization colors were determined for thin fibers (0.8 micron or less) an thick fibers, (1.6-2.4 microns). Most thin fibers of collagens and p-N-collagens showed green to yellowish-green polarization colors with no marked differences between the various samples. Thick fibers of all p-N-collagens, lathyritic and normal 0.15 M NaCl-soluble collagens showed green to greenish-yellow polarization colors, while in all other collagens, polarization colors of longer wavelengths (from yellowish-orange to red) were observed. These data suggested that fiber thickness was not the only factor involved in determining the polarization colors of Picrosirius red-stained collagens. Tightly packed and presumably, better aligned collagen molecules showed polarization colors of longer wavelengths. Thus, packing of collagen molecules and not only fiber thickness plays a role in the pattern of polarization colors of Picrosirius red-stained collagens.

Animals↗
PubMed1989

The feasibility of in vivo resection of the left lobe of the liver and its use for transplantation.

The anatomical possibility of resecting the left lobe of the liver (segments II and III) in living subjects and using it for transplantation was evaluated. A group of 60 cadaveric livers were dissected at autopsy. The vascular and biliary elements of the left lobe were isolated and the lobe was resected and evaluated for possible grafting. The left lobe was 12-28% (mean 19.4%) of the liver mass. An extrahepatic segment of the left hepatic vein was isolated in 95% of specimens. Arterial blood supply to the left lobe consisted of a single artery (92%) or two arteries (8%). A single portal vein segment to the left lobe (type I) was found in 35% livers. Portal vein branches originated from a common orifice (type II, 35%) or separately (type III, 30%) from the left portal vein, and in these instances, preparation of a portal segment necessitated partial section of the left portal vein wall. Biliary drainage was extrahepatic in 56 livers and consisted of a single duct (type I, 78%), or two ducts (type II, 15%). The resected left lobe was evaluated as satisfactory (single hepatic vein and artery, types I or II portal vein, type I bile duct) in 48% of cases, while a less-satisfactory lobe (type III portal vein or type II bile duct) was obtained in 33%. It was found anatomically difficult or impossible to resect the left lobe for possible transplantation in 11 (19%) liver specimens.

Adolescent↗
PubMed1988

Clinical features of sarcoidosis in elderly patients.

We reviewed 17 cases of biopsy-proven sarcoidosis occurring in patients who were 65 years of age or older at the time of diagnosis in order to determine the clinical features of sarcoidosis in this group of elderly patients. A female preponderance (76%) was noted, as well as significant respiratory and cutaneous symptoms. There were no characteristic diagnostic features of sarcoidosis in this group; therefore, we suggest that tissue biopsy is needed to exclude pulmonary diseases such as neoplasm or tuberculosis. Most elderly patients having sarcoidosis remained clinically stable during the period of follow-up and did not require therapy for sarcoidosis. We propose that sarcoidosis should be considered in the differential diagnosis of elderly patients presenting with pulmonary or multisystem disease.

Aged↗