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Allelic imbalance or loss of heterozygosity (LOH) studies have been used extensively to identify regions on chromosomes that may contain putative tumour-suppressor genes. We have undertaken an extensive allelotype of 80 specimens of squamous cell carcinoma of the head and neck (SCCHN) using 145 polymorphic microsatellite markers on 39 chromosome arms. Allelic imbalances were found most frequently on chromosome arms 3p, 9p, 17p and 18q with over 45% LOH and imbalances on 1p, 1q, 2p, 5q, 6p, 6q, 8p, 8q, 9q, 11q, 13q, 17q and 19q were found in more than 20% of SCCHN. These LOH data were analysed against a range of clinicopathological parameters which included previously untreated and previously treated tumours; correlations were found between LOH on 9q and nodes at pathology (P = 0.02) and between histopathological grade and LOH on 12q (P = 0.02) and 13q (P = 0.01). In the group of previously untreated tumours, a correlation was found between site of tumour and LOH on 3p (P = 0.019), and 8p (P = 0.029), while TNM staging correlated with LOH on 3p (P = 0.019) and 17p (P = 0.016). Fractional allele loss (FAL) was calculated for 52 tumours with LOH data on nine or more chromosomal arms and found to have a median value of 0.22 (range 0.0-0.80). Correlations were found between FAL > median value and nodes at pathology (P = 0.01) and tumour grade (P = 0.06), demonstrating that advanced tumours with lymph node metastasis often had LOH at multiple sites. FAL > median value was found to correlate with a poor survival (P < 0.03) and, furthermore, FAL > median value correlated with poor survival in the previously untreated patients (P < 0.019). These results indicate that assessment of the accumulation of genetic damage, as provided by allelotype data, provides a useful molecular indicator of the tumour behaviour and clinical outcome.

While globus pharyngeus is a common disorder, accounting for 3% to 4% of new otolaryngology outpatient referrals, few long-term follow-up studies have been conducted on patients with this condition. The authors of this study followed 74 patients with a diagnosis of globus pharyngeus for an average of 7 years, 7 months (range: 7 years to 8 years, 10 months). During the follow-up period, 55% of patients were asymptomatic and 45% of patients had persistent symptoms. An in-depth analysis of features at clinical presentation failed to reveal any reliable prognostic indicators. A number of patients developed other conditions during the follow-up period, but no patient developed upper aerodigestive tract malignancy. This study represents the longest follow-up of globus patients to date and, to the authors' knowledge, is the first to address the issue of malignancy in globus.

The effects of maximal electroshock, used as a model of generalized seizures, were studied on extracellular GABA and glutamate levels in the ventral hippocampus of the freely-moving rat, using in vivo microdialysis. Following a maximal electroshock there was a rapid decline in GABA levels (46 +/- 5%) in the 20 min immediately after the seizure and levels remained depressed for a further 60 min. However, although there was a transient small decrease (11 +/- 2%) in glutamate levels in the first 20 min post-ictally, there followed a more prolonged, larger increase in the next 40 min. Maximal electroshock, administered in the absence of extracellular calcium, did not change GABA levels, while glutamate levels were again increased (42 +/- 8%) in the 40-80 min after the shock. Local perfusion with nickel (1 mM) to block T-type calcium channels had no effect on basal GABA or glutamate levels but prevented maximal electroshock-induced changes in both amino acids. Experiments were carried out to test the hypothesis that the post-ictal increased glutamate release was due to the decrease in GABA release. Perfusion with the potent GABA re-uptake inhibitor NNC-711, for 60 min prior to administration of maximal electroshock, increased GABA levels (436 +/- 58%) and abolished the seizure-induced decrease. Basal glutamate levels were not affected by perfusion with NNC-711 but subsequent maximal electroshock also failed to affect levels. Local perfusion with the GABAA receptor antagonist bicuculline (1, 10 and 100 microM) had no effect on basal GABA levels but glutamate levels were increased (46 +/- 5%) after perfusion with 100 microM bicuculline.(ABSTRACT TRUNCATED AT 250 WORDS)

The present study analyses tumour samples from 41 patients with squamous cell carcinoma of the head and neck (SCCHN) using the polymerase chain reaction (PCR) to detect genetic alterations on chromosome 18. Microsatellite markers were used to examine each sample for loss of heterozygosity (LOH) and microsatellite instability. Genetic alterations were most commonly noted on the long arm of chromosome 18 (18q). LOH/microsatellite instability occurred on 18q in 20/41 (49%) of patients. The highest single incidence of LOH was found at 18q21.1-21.3 using the microsatellite marker D18S35. LOH occurred in 10/30 (33%) informative cases while LOH/microsatellite instability occurred in 13/30 (43%) informative cases using this marker. Interestingly the tumour suppressor gene known as the 'deleted in colonic carcinoma' (DCC) gene is located in this region at 18q21.3 but is not commonly lost. This suggests that the marker D18S35 is mapping close to a second as yet unidentified tumour suppressor gene in this area.

This article highlights the patient benefits of noninvasive presurgical mapping using magnetic source imaging, discusses magnetic source imaging in terms of its practical implementation and current limitations in mapping the human cerebral cortex, and illustrates the use of magnetic source imaging in ongoing clinical studies. An overview of preliminary research studies that have attempted to evaluate the accuracy and cost-effectiveness of magnetic source imaging in presurgical mapping is also provided.

We report two cases of polymicrogyria in which maternal insults were well documented during the first half of the second trimester of pregnancy. The clinical histories, MR studies, and, in one patient, autopsy results were carefully reviewed, and the timing and nature of the injuries correlated with known developmental events at the time of the injury. Our results support the theory that polymicrogyria results from injury to, or disruption of normal cellular interactions at, the external limiting membrane (the "glial-pial barrier").

Lymphomas generally have a good prognosis compared with squamous carcinomas. The present study investigates a series of 185 lymphomas of the head and neck seen over a 30-year-period. The records of 236 patients were examined and the histology slides reviewed. The lymphomas were classified according to the working formulation method and staged using the Ann Arbor system. A total of 185 patients had a non-Hodgkin's lymphoma, of those 43 were low grade, nine intermediate and 103 high grade. The histology slides of 30 patients were not available for review. In addition, 51 patients had Hodgkin's disease. One hundred and fifty patients were stage 1 or 2 and 74 stage 3 or 4. In 12 patients insufficient data was available for staging; 152 were extranodal and 84 nodal. The 5-year survival of those patients with Hodgkin's disease was 73%. For the patients with non-Hodgkin's lymphoma the 5-year survival was 43% for low grade and 48% for high grade lesions. The survival of patients with Hodgkin's disease was significantly better than for non-Hodgkin's lymphoma (P < 0.01). The 5-year survival of patients with extranodal disease was 54% and for patients with nodal disease 65% (P = NS). Treatment was by irradiation for localized lesions and by chemotherapy or a combination for more advanced lesions. Lymphomas have a relatively good prognosis in the head and neck as elsewhere in the body and every effort should be made to provide adequate diagnosis and treatment in combined clinics.

Following radiation treatment for carcinoma of the larynx it may be very difficult to differentiate between persistent or recurrent tumour and severe radiation effects particularly chondroradionecrosis. Despite repeated negative biopsy it may be necessary to perform total laryngectomy where the concern about persistent cancer remains and the larynx is non-functioning. We report nine cases presenting as chondroradionecrosis over a five-year period. Two patients settled on medical treatment. Of seven patients treated with laryngectomy the histology on two revealed residual or recurrent carcinoma. We outline the dilemmas in diagnosis and propose management strategies to deal with this condition including recommendations for prevention and treatment.

Purpose: To assess the utility of high-resolution volumetric MR examinations with thin partition size for patients with simple partial epilepsies that were well located with electrical and clinical criteria., Methods: Fifteen patients with normal standard MR findings were studied with three-dimensional Fourier transform volumetric MR examinations using thin (1 to 1.5 mm) partition size. Imaging was done in the coronal plane, then reformatted manually on an independent console with each gyrus analyzed in the planes parallel and perpendicular to its axis., Results: Cortical abnormalities were detected in 8 of the 15 patients in the study. Surgical resection of the affected cortex in 2 patients showed polymicrogyria in one and dysplastic cortical organization in the other., Conclusion: In this preliminary study, 3-D Fourier transform volumetric MR examinations with thin partition size appeared to be useful in identifying cortical dysplasias in patients with localized simple partial epilepsies.

We describe eight patients with reversible MRI changes following seizures. The patients were mostly young with a serious underlying medical problem; MRI abnormalities were localized primarily in the posterior vascular boundary zones. A likely mechanism for these lesions is edema secondary to disruption in the blood-brain barrier. Recognition of the transient radiologic changes may aid in the diagnostic and therapeutic management of seizures.

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.

Parathyroidectomy is an established surgical treatment for symptomatic hyperparathyroidism. In this regional hospital experience, 50 patients who had undergone a parathyroidectomy were looked at. We examined clinical indications and noted trends for hypertension, neuromuscular symptomatology and psychiatric complaints to occur commonly as presenting symptoms. Operative results and histology results are examined and correlated. Particular note is made of any postoperative complications.

Cerebral phaeohyphomycosis (also referred to as cerebral chromomycosis), one of the diseases caused by the dematiaceous (black) fungi, is most commonly caused by Cladosporium trichoides (referred to by some as Xylohypha bantiana) and is a rare disease, with 31 culture-proven cases reported to date. Although most cases have occurred in immunocompetent hosts, recent experimental evidence suggests that host immunosuppression may predispose patients to the disease. The authors report a case of fatal cerebral phaeohyphomycosis in a liver transplant patient, the first to occur in a transplant patient of any type, to the best of the authors' knowledge. This case provides support for the hypothesis that immunosuppressed patients may be at increased risk for development of this disease.

Three young patients developed strokes of rostral midbrain and thalamus shortly following cocaine abuse. Two had infarctions and one had a hemorrhage, but none had clear risk factors other than cocaine for this relatively uncommon type of stroke. Toxicologic analysis confirmed isolated cocaine use in each patient. In the two cases of infarction studied angiographically, one had normal findings and the other had focal narrowing of the P1 segments of the posterior cerebral arteries bilaterally. Since the P1 segment has a uniquely sparse perivascular sympathetic supply, we suggest that direct adrenergic-mediated vasoconstriction is not critical to the production of cocaine-associated stroke.

Magnetic resonance imaging (MRI) was used in 5 patients with clinically definite amyotrophic lateral sclerosis to determine the frequency of central white matter abnormalities. Two patients had symmetrical areas of increased signal intensity seen on MRI extending from the cortex, through the corona radiata, posterior limb of the internal capsule, and cerebral peduncles into the pons. These MRI abnormalities presumably relate to the pathological changes observed by others in the central white matter of patients with amyotrophic lateral sclerosis.

A serological investigation was undertaken of flocks with depressed egg production. No obvious correlation was found between antibody to adenovirus, infectious bronchitis virus or infectious bursal disease virus and this syndrome. No antibody was detected to Newcastle disease virus, Mycoplasma gallisepticum or in most cases to Mycoplasma synoviae. A relationship was found between the development of antibody to a haemagglutinating virus, 127, and depressed egg production. A retrospective survey of fowl sera for antibody to 127 virus indicated the first evidence of its presence in Northern Ireland was in June 1976. If 127 is the aetiological agent of this syndrome, then it appears to have very limited powers of lateral spread and vertical transmission is postulated. It is further postulated that the widespread dissemination of this condition in Western Europe, coupled with its apparent lack of horizontal transmissibility, can best be explained by contamination of a vaccine with 127 virus.

One hundred seventy-four patients (179 admissions) were prospectively evaluated for the subsequent occurrence of upper gastrointestinal ("stress") bleeding after admission to a medical/respiratory intensive care unit. Evidence for either overt or occult gastrointestinal bleeding developed in 25 (14 percent). The group of bleeders had a higher mortality (64 percent versus 9 percent), duration of intensive care unit stay (median 14.2 versus 4.2 days), number of patients requiring mechanical ventilatory support (84 percent versus 26 percent), and duration of such support for those who required it (median 9.5 versus 4.2 days) than the group who did not bleed. In three patients, death was related to bleeding. Upon patients' admission to the intensive care unit, diagnoses of an acute respiratory illness (but not specifically chronic obstructive pulmonary disease), a malignancy, or sepsis were more common among those who subsequently bled. Of factors tested, a coagulopathy and the need for mechanical ventilation were most strongly associated with the risk of bleeding. Other factors did not add to the risk once these two were taken into account. Among patients receiving mechanical ventilation, the risk of overt bleeding was particularly low for those who required such support for less than five days (only 3 percent). It is concluded that (1) significant upper gastrointestinal bleeding occurring after medical intensive care unit admission is an uncommon event, and (2) prolonged mechanical ventilation and/or the presence of a coagulopathy are the most potent risk factors. Medical patients with either of the latter conditions are most likely to benefit from prophylaxis regimens against "stress"-induced upper gastrointestinal bleeding.

[1-14C]Octanoate (OCTO) is rapidly extracted from blood and metabolized by brain. Up to 6 min following an intravenous pulse injection the autoradiographic pattern of brain labeling reflects differences in blood flow and energy metabolism. When animals are given OCTO during visual or somatosensory stimulation the autoradiograms reveal differential labeling of activated pathways. Studies can be performed in 7-20 s allowing fast labeling of functional brain anatomy.