Search PubMed⌕ Search

Biomedical subjects

N M Smith

Publications and source records attributed to N M Smith.

At least 55 records · Page 3Linked to original sources
PubMed1991

Congenital ossifying fibroma (osteofibrous dysplasia) of the tibia--a case report.

Ossifying fibromas of the long bones of the leg are benign lesions occurring in the pediatric age group identical in histological appearance to the similarly named tumor of the jaw in adults. Most frequently presentation occurs after minor trauma with symptoms of a swelling of the tibia or fibula which may be painful. Pathological fracture or limp are also occasional presentations. Congenital cases are extremely rare. We describe an otherwise normal male neonate who presented at birth with a bowed right lower leg. The limb was 1 cm shorter than the other side, with tibia vara and a firm mass situated anteriorly. X-ray showed a mixed lytic and sclerotic lesion in the proximal metaphysis of the tibia. Biopsy showed collagenous stroma containing spindle cells and irregular trabeculae of woven bone rimmed by plump osteoblasts. As the appearances were typical of an ossifying fibroma (osteofibrous dysplasia) no surgical treatment was given. The patient was well with no growth of the tumor and with radiological evidence of healing at 1 year follow up. This case is presented to draw attention to the clinicopathological features of this unusual lesion which must be considered in the differential diagnosis of congenital lesions of the tibia.

Bone Neoplasms↗
PubMed1991

Post cricoid lymphangioma.

A 69-year-old female patient presented with symptoms characteristic of globus pharyngeus and barium swallow examination was normal. Her symptoms persisted and pharyngoscopy was undertaken; a post-cricoid polyp was found and removed. Histological examination revealed this to be a lymphangioma. Histological appearances, pathogenesis and treatment are discussed. The case illustrates that persisting symptoms presenting as globus pharyngeus should be further investigated to exclude rare lesions.

Aged↗
PubMed1991

Death during immersion in water in childhood.

Drowning is a relatively common cause of accidental death in children. Autopsy records at the Adelaide Children's Hospital over a 27-year period from 1964 to 1990 were examined, and 58 cases were found where the cause of death was listed as drowning. In six cases, however, careful examination of the history and postmortem findings provided important additional information that suggested a more complex antemortem sequence of events. Specifically, four patients aged between 6 years, 10 months and 11 years were known to have had epilepsy. A further patient, an 8-year-old boy, died from a subarachnoid hemorrhage due to a bleeding cerebral arteriovenous malformation while swimming. The final patient, an 11-year-old boy who collapsed in a public swimming pool, was found at autopsy to have marked hypoplasia of the right coronary artery. In this series, six of 58 (10.3%) of the pediatric cases had additional underlying medical problems that could either have initiated the drowning episode or caused death due to alternate mechanisms. We present the clinicopathological findings in detail to demonstrate that a high index of suspicion must be maintained in all cases of pediatric drowning, not only for unnatural causes of death but also for additional natural disease processes that may have contributed significantly to the fatal episode. These findings may have particular relevance in jurisdictions where full postmortem examination is not always required by law.

Accidents↗
PubMed1991

Testicular regression syndrome--a pathological study of 77 cases.

Testicular regression syndrome is characterized by a rudimentary epididymis and spermatic cord with absence of testicular tissue. Although it has been well-described in the surgical literature, few pathological studies have been performed. We report 77 cases of the syndrome, deriving from a 26-year retrospective review. Typical gross descriptions described several cm of spermatic cord with a small mass of firm, fibrotic tissue at one end; elements of the vas deferens, spermatic artery and venous plexuses were usually present. Histologically, the distal expansion of most of the specimens was composed of dense fibrovascular tissue with no evidence of seminiferous tubules or normal testicular elements. Instead, scattered foci of calcification and brown pigment were present. The finding of dystrophic calcification and haemosiderin deposition, with no evidence of viable testicular tissue, in the presence of relatively normal spermatic cord elements, supports the concept of generally unilateral and occasionally bilateral anorchia secondary to remote infarction. The young age of the patients, coupled with the history of an absent testis from birth, is supportive of in utero damage. These histopathological findings provide support for the concept of in utero torsion of the testis as the basis for the testicular regression syndrome.

Adolescent↗
PubMed1991

Incidental cardiac rhabdomyomas: a significant finding necessitating additional investigation at the time of autopsy.

Cardiac rhabdomyomas are rare lesions forming part of the tuberous sclerosis complex that may be responsible for sudden death. As well as remaining clinically occult for variable periods of time, they may, along with other manifestations of tuberous sclerosis, be quite difficult to detect clinically and pathologically. A patient is described in whom multiple cardiac rhabdomyomas were an incidental finding at autopsy following fatal potassium fluoride poisoning. Other gross pathological lesions typical of tuberous sclerosis were present but were quite subtle in appearance. Awareness of the association of cardiac rhabdomyomas with tuberous sclerosis is important so that full examination of organ systems for characteristic lesions can be undertaken during the autopsy, and so that fresh and frozen tissue can be obtained at the time of dissection for further investigation.

Cerebral Cortex↗
PubMed1991

Association of right coronary artery hypoplasia with sudden death in an eleven-year-old child.

Congenital coronary artery abnormalities are a rare but well-documented cause of sudden and unexpected death in the pediatric age group. Most reported cases involve both an aberrant origin and course of the abnormal vessel. A case of unexpected death occurring in an otherwise healthy eleven-year-old boy, who had been previously investigated for sudden collapse, is described. The major finding at autopsy was marked disparity in diameter between the coronary arteries due to diffuse hypoplasia of the right coronary artery. This case demonstrates the importance of meticulous examination of the coronary artery system in cases of sudden death in childhood so that significant reduction in luminal cross section will be adequately documented. The possible role played by this finding in the etiology of sudden death is discussed.

Child↗
PubMed1991

Analytic variability and clinical significance of different assays for serum estradiol.

Recent reports in the clinical laboratory literature have raised questions about the accuracy of different methods of measuring serum estradiol. To determine whether between-method variability was clinically significant, we used five different commercial radioimmunoassay methods to measure the concentration of estradiol in sera from nine patients undergoing induction of ovulation for gamete intrafallopian transfer. There were large differences between the estradiol concentrations measured in the same samples by the different methods. Furthermore, apparent changes in concentration that would be regarded as clinically significant may reflect nothing more than the imprecision of the assay. Physicians using serum estradiol measurements to support therapeutic decisions should be aware that an excessive reliance on those measurements may be misleading.

Adult↗
PubMed1989

Return of fertility after twelve years of autoimmune ovarian failure.

Autoimmune ovarian failure is widely regarded as irreversible, although ovarian biopsy characteristically shows follicles surrounded by lymphocytes. Two previous reports of pregnancy in this condition both followed institution of steroid replacement therapy (Finer et al., 1985; Cowchock et al., 1988). We report a case in which fertility spontaneously returned to normal twelve years after the diagnosis of autoimmune ovarian failure.

Adult↗
PubMed1989

Toxic reaction to inhaled paint fumes.

An acute confusional state was observed to follow heavy exposure to polyurethane gloss paint fumes in a previously healthy 60 year old man. This state remitted over a 3-day period, but was followed by transient bone marrow suppression and evidence of liver cell damage. The corroborated absence of other toxins and the temporal association of exposure to paint fumes suggest that a volatile paint component was responsible. White spirit is the major volatile solvent in polyurethane gloss paint. Ingestion of related aliphatic hydrocarbons has been reported to cause nausea, drowsiness and hepatotoxicity, but these symptoms have not previously been documented following excessive inadvertent inhalation of paint fumes.

Air Pollutants↗
PubMed1988

Referral of pediatric oncology patients for marrow transplantation and the process of informed consent.

A survey of 24 pediatric oncologists from 21 institutions not performing bone marrow transplants found that 156 patients were referred for transplants in the years 1984/85; only 10 of these patients were not transplanted. No patient in good clinical condition whose disease was under control was denied transplantation after evaluation at a transplant center. The decision for transplantation was made by the families and the referring pediatric oncologists, almost always before the patient was seen at a transplant center. The fact that almost all patient and family evaluations at transplant centers take place after a family has decided to have a marrow transplant has obvious implications regarding informed consent. Referring pediatric oncologists must attempt to provide the best possible information to families when decisions regarding marrow transplantation are actually being made.

Bone Marrow Transplantation↗
PubMed1988

Immunohistochemical definition of antigenic determinants of pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) using monoclonal antibodies.

Human pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) is a high molecular weight glycoprotein in normal sera. The protein is present in high concentration in the sera of pregnant females and in abnormally low concentration in association with conditions connected with abnormalities of mucosal immunity. Indirect immunoperoxidase techniques using poly- and monoclonal antibodies were employed to identify pregnancy-associated alpha 2-PAG in different tissues. Four monoclonal antibodies were selected from a battery of antibodies with defined specificities in order to ascertain reactivity with various epitopes of the antigen. The antibodies were applied to paraffin sections of breast, colon, salivary gland, and tonsil, and different fixation regimes were used in the preparation of the tissues. The polyclonal antibodies were found to stain plasma cells and epithelial lumina evenly in all the tissues included whereas the monoclonal antibodies were shown to stain certain components selectively. In breast and salivary glands, all four monoclonal antibodies could identify alpha 2-PAG, but in tonsil and colon, only two were reactive. This difference in epitope expression might reflect the internal processing of alpha 2-PAG, and lack of availability of certain epitopes may be indicative of functional blocking of certain domains.

Antibodies, Monoclonal↗
PubMed1987

Chronic periphlebitis retinae in multiple sclerosis. A histopathological study.

Retinal periphlebitis in multiple sclerosis is of particular interest in relation to our understanding of the pathogenesis of the demyelinating central nervous system plaques. Previous studies have largely been clinical, and there is little detailed histopathological information relating to this condition. We present the first detailed report in the neurological literature on the histological findings in chronic periphlebitis retinae associated with multiple sclerosis. The most significant abnormalities of the affected retinal veins were the presence of thick laminated collagen in the wall, associated with a scanty infiltration of plasma cells.

Adolescent↗
PubMed1986

Role of sog polypeptides specified by plasmid ColIb-P9 and their transfer between conjugating bacteria.

The sog gene of the conjugative plasmid ColIb-P9 specifies two sequence-related polypeptides with the N-terminal third of the larger product having DNA primase activity. To resolve the function of the C-terminal portion of the polypeptides, we constructed a ColIb mutant containing a Tn5 insertion in the 3' region of sog. The mutation truncated sog gene products without inactivating DNA primase and rendered the plasmid defective in conjugation. Tests for the presence of conjugative pili, for complementation by a sog+ recombinant, and for mobilization of small origin of transfer (oriT) recombinant plasmids indicated that the mutant ColIb allows conjugative aggregation of cells but it is defective in DNA transfer at some stage subsequent to its initiation at oriT. Physical evidence is given that normal sog polypeptides are among a group of proteins transferred selectively from the donor to the recipient cell by a conjugation-specific process. No transfer of the mutant sog proteins was detected. It is proposed that the C-terminal region of sog polypeptides facilitates transfer of single-stranded ColIb DNA between conjugating cells following initiation of transfer at the oriT site, and that in this role the proteins are transmitted to the recipient cell.

Bacterial Proteins↗
PubMed1986

Simultaneous AL-type amyloid and light chain deposit disease in a liver biopsy: a case report.

A 57-year-old male caucasian presented with a peripheral neuropathy which had an autonomic component. Clinical examination revealed hepatomegaly and laboratory tests showed derangement of liver function tests and IgG lambda myeloma. Biopsy of the liver was performed. Histological examination revealed AL-type amyloid in the hepatic arteries and a perisinusoidal deposit of diastase resistant, periodic acid-Schiff positive material which did not react in the same way as the arterial deposit, giving no apple green birefringence when stained with Congo red. Immunohistochemistry showed the material to consist of lambda light chains. Electron microscopy confirmed that the material did not have the ultrastructural characteristics of amyloid. A diagnosis of light chain deposit disease concurrent with vascular AL-type amyloid was made.

Amyloid↗
PubMed1983

Enzyme patterns in D. melanogaster imaginal discs: distribution of glucose-6-phosphate and 6-phosphogluconate dehydrogenase.

Distribution of glucose-6-phosphate dehydrogenase (G6PD) and 6-phospho-gluconate dehydrogenase (6PGD) in imaginal discs of Drosophila melanogaster was determined. Differential patterns of staining were found in all discs examined, i.e., eye-antennal, wing, leg, labial and genital. By using null mutants for either G6PD or 6PGD, the enzymes were shown to have the same distribution patterns. Staining with glucose-6-phosphate as a substrate resulted in the detection of both G6PD and 6PGD. Results of staining discs from homoeotic mutants indicate that the enzyme distribution patterns are under genetic control. In the presence of the homoeotic engrailed (en) mutation which transforms posterior wing compartment into anterior, the G6PD pattern of the posterior compartment of the wing disc was specifically transformed toward that of the anterior compartment. The bithorax series of homoeotic mutants was similarly investigated. The bithorax (bx3) mutation transforms the anterior part of the haltere to anterior wing blade. Similarly the G6PD pattern in the anterior haltere disc transforms to that of anterior wing disc. The complimentary transformation, postbithorax (pbx) results in a change of the posterior part of the haltere to posterior wing, which is likewise reflected in an altered staining pattern for G6PD in the posterior portion of the haltere disc. The combination of the bx3 and pbx resulted in a staining pattern of the haltere disc virtually indistinguishable from the normal wing disc.

Animals↗
PubMed1981

The relationship between the Rorschach whole response and level of cognitive functioning.

Investigated the relationship between children's level of cognitive development and their production of whole responses (W) on the Rorschach, Both quantitative and qualitative variations in W were examined, and level of cognitive functioning was assessed by Piagetian techniques. The findings indicate that there is a significant and positive relationship between children's stage of cognitive development within the Piagetian framework and the number and complexity of whole responses they produce on the Rorschach. The strength of this relationship appears to be significantly influenced by the stimulus complexity of the inkblots, and the findings suggest that production of highly articulated W on the more complex broken blots requires the abstracting and synthesizing abilities associated with formal operational thought.

Journal Article↗
PubMedDate not supplied

Heart block and sudden death associated with fibrosis of the conduction system at the margin of a ventricular septal defect.

Isolated ventricular septal defects in clinically well patients are not generally thought to cause sudden death. We document a case in which heart block, with sudden collapse and death, is related to the presence of fibrous interruption of the conduction system of the heart due to progressive fibrous closure of a small ventricular septal defect.

Fatal Outcome↗