Search PubMed⌕ Search

Biomedical subjects

M McDermott

Publications and source records attributed to M McDermott.

At least 73 records · Page 4Linked to original sources
PubMed1996

Pleomorphic adenoma of the bronchus.

An example of pleomorphic adenoma of the bronchus is described in a 27 year old male student who was referred for evaluation of a coin lesion identified incidentally on chest x ray. The tumour exhibited the classic histological, immunohistochemical and ultrastructural features of this rare entity but, in addition, contained mature and immature adipose tissue in the stroma and showed transition, in its superficial portion, between ostensibly normal bronchial mucus glands and tumour tubules. Neither of these features has been commented upon previously.

Adenoma, Pleomorphic↗
PubMed1995

Multiple sclerosis. Sexual dysfunction and its response to medications.

OBJECTIVE: To determine the frequency and nature of sexual dysfunction, as well as its response to medications, in a sample of patients with multiple sclerosis (MS). DESIGN: Retrospective and prospective survey of 65 female and 36 male patients with MS. RESULTS: Sixty-three percent of patients reported that they had less sexual activity, and 35% said that they had less interest in lovemaking than before their diagnosis of MS. Fifty-seven patients reported that they had problems with sexual dysfunction. Sexual dysfunction preceded the diagnosis of MS in only 10 of these patients. A higher percentage of men (78%) than women (45%) reported that they experienced sexual dysfunction (P = .002). Men had prominent erectile dysfunction, women had problems with vaginal lubrication, and both sexes had problems with decreased sensation and achieving orgasm. The presence of sexual dysfunction was associated with the presence of urinary problems (P = .02) and with a history of treatment of (P = .04) or a current report of (P = .02) depression. No association could be found between sexual dysfunction and duration of disease, type of disease, disability score, or presence of fatigue. Twenty of 57 patients with sexual dysfunction reported that they had associated marital problems. Forty-three of 60 patients who discussed sexual problems with their spouses and four of six who tried formal counseling found it helpful. Surprisingly, corticosteroid treatments that were started for problems other than sexual dysfunction resulted in improved sexual functioning in many patients. CONCLUSIONS: Sexual dysfunction is common in patients with MS. Determining the frequency and nature of problems allows issues of sexual dysfunction to be addressed as part of comprehensive care of patients with MS and suggests treatments that could improve their quality of life.

Adrenal Cortex Hormones↗
PubMed1995

Cavernous malformations: results of image-guided resection.

With increased use of magnetic resonance imaging (MRI), diagnosis of cavernous malformations (CMs) has become straightforward. Surgical excision is the treatment of choice for these lesions. These malformations, though, are often small and can be difficult to localize during surgery. In these cases, stereotactic resection with a frame-based system is recommended to aid in localization of the malformation. However, use of these frame-based systems can be time consuming for the surgeon and onerous for the patient. With the advent of frameless stereotactic systems, these problems can be circumvented. Therefore, stereotactic resection of 17 CMs was performed for 15 patients over the course of 2 years at our institution during an investigative trial of a frameless stereotactic device. Eight patients presented with seizures, five patients with hemorrhage, and two patients with progressive headaches. Twelve of fifteen patients had normal neurological examination results on presentation, whereas three patients had deficits resulting from intracranial hemorrhages. All patients underwent diagnostic MRI preoperatively. Fourteen lesions were found to be cortical and subcortical; the other three lesions were in the basal ganglia, lateral ventricle, and pons. Following resection, 11 of 15 patients improved. Two patients developed postoperative deficits shortly after resection. One patient with a preoperative neurological deficit remained unchanged, and one patient had a recurrence of a deficit several months following resection. Image-guided stereotactic resection provides for easy localization of small malformations without requiring the use of a stereotactic frame or retractor and is well suited for resection of cavernous malformations.

Adolescent↗
PubMed1995

Correlation of functional magnetic source imaging with intraoperative cortical stimulation in neurosurgical patients.

This study compared noninvasive preoperative functional imaging by using magnetoencephalography (MEG) with intraoperative direct cortical stimulation in ten patients undergoing neurosurgery. The goal was to assess the accuracy and reliability of MEG-based functional imaging in these patients as a possible replacement or adjunct for direct cortical stimulation with electrocorticography. Objective comparison of intraoperative mapping with preoperative MEG procedures was achieved by intraoperative recording of mapped cortical locations for motor responses using an interactive image-guided surgical device, the ISG viewing wand, with which mapping points could be marked on a previously acquired (MRI) set. In all ten patients, at least one stimulation site elicited a response during both MEG and intraoperative mapping. The central sulcus ipsilateral to the lesion was only directly visible on high-resolution MRIs in 3/10 cases and equivocally in 2/10. Coregistered with MRI to form magnetic source images (MSIs), MEG predictions of the postcentral gyrus were possible in all 10 cases. In all 10 cases, these were in agreement with intraoperative estimation of the precentral gyrus. Functional mapping of somatosensory cortex was achieved noninvasively in surgical patients by using MSI. The accuracy, compared with cortical stimulation, was always sufficient to define motor and somatosensory strips.

Adult↗
PubMed1995

The role of T cell receptor beta chain genes in susceptibility to rheumatoid arthritis.

OBJECTIVE: To evaluate the role of the T cell receptor beta chain locus (TCRB) in genetic susceptibility to rheumatoid arthritis (RA). METHODS: Twenty-eight multiplex RA families were recruited from 3 rheumatology outpatient departments. All members were genotyped for a highly informative microsatellite (V beta 6.7), a V beta 12.2 SSCP marker, and a biallelic C beta restriction fragment length polymorphism. Data were analyzed by the SIBPAL program to assess identity-by-descent in affected sib-pairs. RESULTS: Using the V beta 12.2 marker, there was suggestive evidence of increased sib-pair sharing (P = 0.005) in affected offspring (a P value of 0.001 is generally taken to establish linkage). Data for V beta 6.7 and C beta yielded significance levels of 0.06 and 0.19, respectively. CONCLUSION: These data suggest that a gene in or linked to the TCRB complex may confer genetic susceptibility to RA in these families. Confirmation in a larger panel of families is required.

Adolescent↗
PubMed1995

Non-linkage of a T-cell receptor gamma chain microsatellite (D7S485) to rheumatoid arthritis in multiplex families.

A highly informative microsatellite marker, D7S485, from the T-cell receptor gamma (TCRG) locus, has been used to study segregation of TCRG genes in 26 multiplex rheumatoid arthritis (RA) families. We used the sib-pair method to assess excess identity-by-descent sharing among affected members in these families and the LINKAGE package of programs was used to calculate two-point lod scores for the D7S485 marker. There was no evidence for segregation of TCRG genes with RA in affected siblings and significantly negative lod scores were obtained from linkage analyses using both autosomal dominant and recessive models of inheritance.

Adolescent↗
PubMed1995

Helicobacter pylori infection increases following cholecystectomy.

Cholecystectomy is frequently linked with duodenogastric reflux and gastritis but its effect on Helicobacter Pylori (H pylori) infection has not been examined. In a prospective study, twenty two patients with documented cholelithiasis underwent upper gastrointestinal endoscopy and biopsy and 24hr dual channel pH monitoring prior to cholecystectomy and again at 3-6 months post-operatively. The antral biopsies were histologically assessed for H pylori and gastritis and awarded an alkaline reflux score. The number of patients with H pylori infection increased from 7 (32%) preoperatively to 15 (68%) post-cholecystectomy (p < 0.05). Cholecystectomy was also associated with an increase in the incidence of gastritis from 7 to 15 (p < 0.05). The increase in H pylori infection rate occurred in association with an increase in the percentage time gastric pH > 4 in the supine position, from 9.6 (2.2) to 22.2 (4.8) percent, (p < 0.01). The median chemical gastritis score, however, did not change significantly following surgery [8(3-11) vs 7(3-11)]. Seven patients remained symptomatic following cholecystectomy all of whom were H pylori positive and had gastritis. H pylori can survive in the alkaline environment which follows cholecystectomy and may contribute to the post-cholecystectomy syndrome.

Adult↗
PubMed1995

Chronic reduction in fetal blood flow is associated with placental infarction.

The placenta receives two arterial blood supplies, i.e. one maternal and one fetal. It has been suggested that placental infarction should occur only if both blood supplies are compromised (Wigglesworth, 1984). This hypothesis has not been tested. Haemosiderosis of the trophoblast basement membrane (TBMH) has recently been identified as a feature of fetal artery thrombosis and suggested as a marker of impaired fetal blood flow which is identifiable in both viable and necrotic tissue. We examined 50 placental infarcts for evidence of TBMH, both grossly and microscopically. These were compared with four types of control tissue. Eleven placentae from cases of prolonged intrauterine death, in which this feature was first described, and 35 fetal artery thromboses were used as positive controls and 20 placentae from uncomplicated pregnancies were available as negative controls. Non-infarcted tissue adjacent to infarcts served as an internal negative control. Non-infarcted tissue adjacent to infarcts served as an internal negative control. Microscopically, 36 per cent of infarcts showed TBMH in at least 5 per cent of villi within the lesion and 60 per cent of infarcts showed at least one cluster of villi with the feature. These findings point to a disturbance in fetal blood flow intimately associated with but pre-dating the placental infarction. These findings represent the first experimental evidence to support Wigglesworth's theory and suggest that reduction in fetal blood flow prior to thrombosis of maternal vessels contributes to the pathophysiology of placental infarction.

Chorion↗
PubMed1995

Trophoblast basement membrane haemosiderosis in the placental lesion of fetal artery thrombosis: a marker for disturbance of maternofetal transfer?

The placental lesion of fetal artery thromboses is characterized by collapse and obliteration of chorionic vasculature, an increase in stromal connective tissue and syncytial knots, with a thickening of trophoblast basement membrane. An additional feature, not previously described in association with the lesion, is linear trophoblast basement membrane haemosiderosis. Thirty-five such lesions were examined for this feature which was identified in 32. Random tissue sections of placentae from cases of intrauterine death showed a similar basement membrane haemosiderosis and were used as positive controls. None of 20 normal control cases examined demonstrated the feature. Electron microscopy demonstrated electron-dense bodies within the basement membrane. Spectrographic analyses confirmed the presence of iron within these deposits. The significance of this finding lies not so much in the fact that it is an additional finding in fetal artery thrombosis but rather in the underlying pathophysiology.

Basement Membrane↗
PubMed1995

Chemical gastritis induced by naproxen in the absence of Helicobacter pylori infection.

AIM: To evaluate the histological changes that occur in the antral mucosa of healthy male subjects before and after one week of naproxen administration, using a chemical gastritis score according to the Helicobacter pylori status. METHODS: Nineteen male subjects (mean age 31 years) underwent two endoscopies: one before and the other after one week of naproxen treatment (1 g daily). Antral biopsy specimens were assessed for the presence of H pylori infection and for chemical gastritis, defined as the presence of foveolar hyperplasia, muscle fibres in the lamina propria, oedema, and vasodilatation, in the absence of acute or chronic inflammatory cell infiltrate. RESULTS: Of the 19 subjects, eight had H pylori infection. After one week of naproxen treatment, none of those with H pylori infection developed chemical gastritis, while five of 11 (45%) of those without H pylori infection did. In the absence of H pylori infection there was no evidence of inflammation, either before or after naproxen administration. CONCLUSIONS: A different pattern of antral histological change occurs following naproxen administration. This pattern is related to the presence or absence of H pylori infection, suggesting that H pylori status should be determined in histological studies of subjects taking non-steroidal anti-inflammatory drugs.

Adult↗
PubMed1995

Stereotactic radiosurgery in children.

The role of stereotactic radiosurgery in the treatment of pediatric patients is still being explored. We report the Gamma Knife treatment of 33 patients under the age of 21, at the University of California, San Francisco, between the years 1991 and 1993. Treatment-related toxicity has been low. 10/14 patients treated for arteriovenous malformation (AVM) with follow-up > 1 month have shown partial or complete AVM obliteration. No patient has had a new hemorrhage after AVM treatment. In children with malignant tumors, treatment was well tolerated, although most patients, ultimately, had progressive disease. Stereotactic radiosurgery is logistically possible in the pediatric population. Its use in selected patients with AVMs seems appropriate, although its role in the treatment of malignant brain tumors remains to be defined.

Adolescent↗
PubMed1995

Monozygotic twins with facioscapulohumeral dystrophy (FSHD): implications for genotype/phenotype correlation. FSH-DY Group.

Facioscapulohumeral dystrophy (FSHD) is an autosomal-dominant disorder with a characteristic and distinctive distribution of weakness but a high degree of variation in the age of onset and rate of progression. Monozygotic twins provide the opportunity to assess the relative importance of genetic as opposed to nongenetic influences on the course of disease. We have studied three sets of monozygotic twins with FSHD and compared the similarity of their degree of involvement using quantitative studies of individual muscle function. Similar quantitative studies of 59 other subjects with FSHD served as a reference population for contrast with the twin studies. One set of twins was discordant for FSHD, presumably as a reflection of a postzygotic mutation in the affected twin. The other two sets were concordant and both had evidence of autosomal dominantly inherited gene rearrangements. Both sets were similarly affected in terms of age of onset, overall degree of disability, and quantitative tests of muscle, but there were major differences in the symmetry of involvement of specific muscles. Cerebral dominance was not related to asymmetries of involvement. These data suggest age of onset and severity are determined by the gene lesion in FSHD. Other factors may influence the frequently encountered asymmetries in FSHD.

Adult↗
PubMed1994

Selective destruction of gliomas in immunocompetent rats by thymidine kinase-defective herpes simplex virus type 1.

BACKGROUND: Thymidine kinase-deficient herpes simplex virus type 1 [tk(-) HSV-1] replicates well in dividing cells but not in nondividing cells such as neurons, suggesting a potential use in the treatment of brain tumors. PURPOSE: We attempted to examine the efficacy of using tk(-) HSV-1 for treating brain tumors in immunocompetent animals. METHODS: 9L glioma cells were cultured and subsequently implanted intracerebrally in immunocompetent, adult male Long-Evans rats. A thymidine kinase-defective HSV-1 virus, KOS-SB, was used to infect 9L cells in culture, and the viability of the infected cells was compared with that of mock-infected (i.e., uninfected) cells. We also injected the virus intratumorally and determined the mortality of the tumor-bearing animals. Tumor regression and viral spread following virus injection were examined by histologic and immunocytochemical assays. RESULTS: In vitro, the tk(-) virus destroyed cultured 9L cell monolayers at multiplicities of infection of 0.1 and 1.0 within 48 hours. With the same quantity of virus, no remarkable difference in survival of neural cells was found. Foscarnet, an antiviral drug that acts independently of tk activity, blocked viral replication by greater than 99% at a concentration of 100 micrograms/mL. The mortality of animals bearing tumors declined with an increase in the amount of virus injected. Histologic examination showed that the HSV-1 treatment caused severe tumor regression. Immunocytochemistry using an anti-HSV-1 antibody revealed only a weak staining within the regressing tumors, and few immunopositive neurons were evident in the surrounding brain tissue. CONCLUSIONS: The results indicate that tk(-) HSV-1 mutants can selectively and effectively destroy glioma cells both in vitro and in vivo in normal, immunocompetent animals. IMPLICATIONS: Our failure to detect viral spread associated with regressing tumors suggests that some other cytopathic factors might be involved in the tumor regression. Regardless of the precise mode of tumor cell killing, HSV-1 may be useful for treating brain tumors.

Animals↗
PubMed1994

Proliferating cell nuclear antigen in the assessment of Barrett's mucosa.

Proliferating cell nuclear antigen (PCNA) expression was assessed in oesophageal epithelium from 70 patients with Barrett's oesophagus. PCNA counts were expressed in the form of a PCNA index. There were 24 patients with dysplastic epithelium, nine with regenerative atypia, 18 with benign histology and 19 with adenocarcinoma arising in Barrett's epithelium. The PCNA index of malignant tissue was significantly different from that of benign (P < 0.001) and dysplastic (P < 0.05) specimens. PCNA indices in histologically normal Barrett's epithelium adjacent to a tumour were significantly different (P < 0.001) from those in normal Barrett's epithelium with no adjacent tumour. These findings support the use of PCNA measurement in the assessment of Barrett's epithelium.

Adenocarcinoma↗
PubMed1994

Adhesions after laparoscopic inguinal hernia repair. A comparison of extra versus intra peritoneal placement of a polypropylene mesh in an animal model.

Prosthetic mesh for laparoscopic inguinal hernia repair has become popular but the method of its placement is controversial. Mesh placed within the peritoneum may cause adhesion formation and further complications. The aim of this study was to examine the laparoscopic placement of a mesh, comparing intraperitoneal vs extraperitoneal insertion. In a porcine model (n = 15) a polypropylene mesh was placed laparoscopically over the anterior abdominal wall. On the left side the mesh was stapled on the parietal peritoneum. On the right side the peritoneum was incised, an extraperitoneal space was dissected, the mesh was inserted, and the peritoneum was closed over it. The animals were maintained for 2 weeks. At postmortem there were adhesions in two of those placed extraperitoneally and five of those placed intraperitoneally (P = 0.19, Fisher's exact test). The adhesions comprised fibrous peritoneal bands to loops of small intestine. Both methods of laparoscopic mesh placement were associated with a small but significant incidence of adhesion formation.

Animals↗