Unusual lesions of the internal auditory canal

Acoustic neuromata (AN) account for nearly 90 per cent of internal auditory canal (IAC) and cerebello-pontine angle (CPA) tumours. The second most common tumour is meningioma. Rare lesions include primary cholesteatoma, facial neuroma, lipoma, angioma and various cysts. Two cases of IAC tumour are presented, one of hamartoma in which smooth muscle was prominent and the other of lymphangioma. Of interest are the specific clinical and radiological features associated with these lesions.

Relaxivity of Gd-EOB-DTPA in the normal and biliary obstructed guinea pig

After injection of Gd-EOB-DTPA, T1 and T2 were determined on a clinical MR scanner (1.5 T) in the liver and kidneys of sacrificed but intact guinea pigs with normal and obstructed biliary systems and in bile, urine, and blood collected postmortem. Tissue [Gd] was determined by radioassay of 153Gd and relaxivities (R1 and R2; units of s(-1) x mmol(-1) x kg) of Gd-EOB-DTPA calculated. Compared with R1 in 2% agarose gel (4.49 +/- 0.03), in normal animals R1 was increased in liver (9.3 +/- 0.5), similar in kidney cortex (4.1 +/- 0.5), but reduced in kidney medulla (2.5 +/- 0.4) and papilla (2.7 +/- 0.4). Chronic biliary obstruction did not change R1 in liver (9.7 +/- 4.3) but reduced R1 further in kidney tissues (1.0-0.4). In normal animals, R2 values of all tissues (9.5-18.4) were greater than R2 in gel (5.72 +/- 0.12). Biliary obstruction possibly elevated R2 in liver (40.1 +/- 63.5), severely depressed R2 in kidney cortex (-4.2 +/- 6.2) and medulla (-2.3 +/- 5.4), and reduced R2 in papilla (5.4 +/- 4.6). Obstruction had little effect on R1 and R2 in bile and urine. Water content, macromolecular binding, microviscosity, compartmentalization, and susceptibility effects can readily account for the R1 and R2 observed in liver and kidney. Negative R2 could be a result of several factors, including reduced endogenous magnetic field gradients due to "susceptibility matching" as [Gd] increased, changes in tissue T2 with period of ligation, or a physiological effect of EOB-DTPA. These results show that disease can alter both R1 and R2 from their values in normal tissues.

Imaging destructive lesions of the petrous apex

Cholesterol granuloma and cholesteatoma are the two most common destructive lesions of the petrous apex. Arachnoid cyst is less common. These three expansile lesions are often indistinguishable on clinical grounds. Cholesterol granulomas can be treated effectively through internal drainage into the mastoid cavity or middle ear. Cholesteatomas, however, are managed by more aggressive and complicated removal, which often mandates the sacrifice of hearing. Symptomatic arachnoid cysts are amenable to simple surgical drainage. Therefore, accurate preoperative recognition on computed tomography (CT) and magnetic resonance imaging (MRI) is important in planning proper treatment. Thirteen cases of destructive lesions of the petrous apex are analyzed. The authors' experience illustrates that the "typical" CT and MRI radiographic features are diagnostic in some cases, but not in all. In this study the pathologic findings have been correlated with the radiologic features on both MRI and CT.

Surgical thrombectomy and stent placement for iliac compression syndrome

There have been several methods, both surgical and radiological, to attempt to treat ilio-femoral thrombosis secondary to the iliac compression syndrome. A case is reported here which was managed by a combination of surgical thrombectomy and radiological stenting of the left common iliac vein.

Epidemic of accidental carbon monoxide poisonings caused by snow-obstructed exhaust systems

We report a case series of accidental carbon monoxide poisonings caused by snow-obstructed automobile exhaust systems. Accumulation of more than 24 inches of snow contributed to the poisoning of 25 patients who were subsequently treated with hyperbaric oxygen therapy. Two illustrative cases are presented in greater detail, illustrating a life-threatening hazard associated with heavy snow accumulations.

Chromosome 3p14 homozygous deletions and sequence analysis of FRA3B

Loss of heterozygosity (LOH) involving 3p occurs in many carcinomas but is complicated by the identification of four distinct homozygous deletion regions. One putative target, 3p14.2, contains the common fragile site, FRA3B, a hereditary renal carcinoma-associated 3;8 translocation and the candidate tumor suppressor gene, FHIT. Using a approximately 300 kb comsid/lambda contig, we identified homozygous deletions in cervix, breast, lung and colorectal carcinoma cell lines. The smallest deletion (CC19) was shown not to involve FHIT coding exons and no DNA sequence alterations were present in the transcript. We also detected discontinuous deletions as well as deletions in non-tumor DNAs, suggesting that FHIT is not a selective target. Further, we demonstrate that some reported FHIT aberrations represent normal splicing variation. DNA sequence analysis of 110 kb demonstrated that the region is high in A-T content, LINEs and MER repeats, whereas Alu elements are reduced. We note an intriguing similarity in repeat sequence composition between FRA3B and a 152 kb segment from the Fragile-X region. We also identified similarity between a FRA3B segment and a small polydispersed circular DNA. In contrast to the selective loss of a tumor suppressor gene, we propose an alternative hypothesis, that some putative targets including FRA3B may undergo loss as a consequence of genomic instability. This instability is not due to DNA mismatch repair deficiency, but may correlate in part with p53 inactivation.

Episodic facial paralysis due to temporal bone pneumocele: a case report

A case of episodic facial paralysis resulting from a pneumocoele of the temporal bone is presented. The patient had undergone facial nerve exploration and blind sac closure after a transverse fracture of the petrous temporal bone.

Intra-renal Doppler wave-form analysis as a screening test for renal artery stenosis

A double-blinded trial was performed comparing Doppler interrogation of intra-renal arteries with findings at renal angiography in the assessment of renal artery stenosis. Fifty-three consecutive patients were studied. Previously reported parameters and cut-off values were used for predicting the presence of renal artery stenosis with Doppler. Doppler wave-form analysis proved relatively specific (91%) but insensitive (68%) to the presence of renal artery stenosis (of greater than 60%) if acceleration parameters were used alone. The technique of using a difference in mean resistive indices was found to be both insensitive (61%) and non-specific (54%). Patients with fibromuscular dysplasia, branch vessel stenoses, multiple renal arteries and chronic renal impairment proved to cause the most false negatives. Young patients with normal arteries were the source of the few false positive results. The interrogation of intra-renal arteries does not have appropriate sensitivity to be useful as a screening test for renal artery stenosis.

Arachnoid granulations in the transverse and sigmoid sinuses: CT, MR, and MR angiographic appearance of a normal anatomic variation

PURPOSE

To investigate the imaging characteristics, prevalence, and clinical significance of arachnoid granulations in the transverse and sigmoid venous sinuses.

METHODS

We reviewed the imaging findings, clinical signs and symptoms, final diagnoses, and follow-up studies of 32 patients with 41 probable arachnoid granulations.

RESULTS

On CT scans, arachnoid granulations appear as well-defined filling defects, wholly or partly within a venous sinus, with the same density as cerebrospinal fluid. MR images show these entities as largely isointense with cerebrospinal fluid in all sequences. Linear variations of signal intensity within the granulations are thought to be fibrous septa or vessels. Calcification was present in 3 granulations and altered both CT density and MR signal intensity. The granulations appear as filling defects at MR angiography and at digital subtraction angiography. In some oblique MR angiographic projections, they appear elliptical and could be mistaken for thrombus. No clinical significance could be given to the existence of any of these arachnoid granulations. They occur in 0.3 to 1 of 100 adults in the population.

CONCLUSION

Arachnoid granulations in the transverse and sigmoid venous sinuses are common findings seen with thin-section imaging and are usually of no significance.

Distinct 3p21.3 deletions in lung cancer and identification of a new human semaphorin

Loss of chromosome 3p is a critical event in the pathogenesis of lung cancer. Overlapping homozygous 3p21.3 deletions in lung cancer cell lines involving GNAI2 were characterized and found to involve a region of genomic instability. A new widely expressed Semaphorin, H.SemaIV, was isolated from the GNAI2 deletion region. Reduced H.SemaIV expression allowed identification of additional cell lines with submicroscopic or larger deletions of the locus which occurred in a heterogeneous manner. We also demonstrate the presence of a distinct 3p21.3 homozygous deletion region, adjacent to the DNA mismatch repair gene, hMLH1, and identified deletions in direct tumors. This appears to represent one of the first demonstrations of homozygous deletions affecting 3p in direct lung tumors.

White matter magnetic resonance imaging hyperintensity in Alzheimer's disease: correlations with corpus callosum atrophy

We have previously demonstrated with MRI that as well as marked white matter involvement in late-onset Alzheimer's disease (AD), atrophy of the corpus callosum may also be present. This finding prompted us to study possible correlations between atrophy of the corpus callosum and white matter hyperintensity (WMH) and between white matter lesions and the severity of the disease. We compared the corpus callosum and white matter lesions on MRI from 15 AD patients and 15 controls. The white matter lesions were scored according to the Scheltens' rating scale. We found a significant reduction of the area of the corpus callosum and more severe white matter lesions in AD patients than in controls. Both atrophy of the corpus callosum and the severity of lesions depended mainly on the diagnosis of senile dementia of the Alzheimer type and on age but not on the diagnosis of presenile AD. We demonstrated a negative correlation between white matter lesions scores and areas of corpus callosum in AD patients and no correlation between the white matter lesions and the severity of the disease. We demonstrated that white matter lesions including WMH and atrophy of the corpus callosum are more frequent in AD than in controls. The predominance of white matter lesions in senile AD may be explained by the combination of aging and disease processes.

Major role for a 3p21 region and lack of involvement of the t(3;8) breakpoint region in the development of renal cell carcinoma suggested by loss of heterozygosity analysis

In a loss of heterozygosity analysis of 3p, we examined 44 sporadic cases of renal cell carcinoma (RCC) and matched normal tissue with 18 markers distributed over the whole p-arm. The majority of these markers clustered in three regions that have been suggested to be involved in the development of RCC, namely the p25 region, where the von Hippel Lindau (VHL) gene is located; the p21 region, which has been identified as a common region of overlap (SRO) of heterozygous deletions; and the p14 region, which is the location of the constitutional t(3;8) breakpoint occurring in an RCC family. Thirty-one out of these 44 tumors were analyzed with 9 additional markers from the 3p12-14 region to further delimit the SRO in this region. Our analysis shows that when deletions were detected the 3p21 region was always included. The 3p21 markers D3F15S2 and UBEIL were always contained within these 3p21 deletions. The t(3;8) breakpoint region showed the lowest percentage of loss of heterozygosity. Moreover, in three cases the t(3;8) breakpoint region retained heterozygosity, whereas a region more proximal to the breakpoint showed allelic losses. This supports exclusion of the t(3;8) region from a role in the development of sporadic RCC. In a number of tumors, two or three 3p regions with allelic losses were present separated by a region of retention of heterozygosity. In these tumors, deletions at 3p21 occurred in combination with deletions of either the VHL region, or the region proximal to the t(3;8), or both, suggestive of multiple gene involvement in the development of sporadic RCC with a primary role of the 3p21 region.

In vitro susceptibility of Plasmodium falciparum to chloroquine, amodiaquine, quinine, mefloquine, and sulfadoxine/pyrimethamine in Equatorial Guinea

Between March 1990 and June 1992, a study was carried out in Equatorial Guinea on the in vitro response of Plasmodium falciparum to different antimalarial drugs. Field work for the study was conducted both in the country's island region as well as on the mainland, and resistant isolates were found to exhibit interregional differences. On the island of Bioko, 204 tests were performed with 16% (11 of 69) resistant to chloroquine, 9% (4 of 46) resistant to quinine, 14% (6 of 43) resistant to a combination of sulfadoxine/pyrimethamine, and 6.5% (3 of 46) resistant to amodiaquine. In the mainland area of Bata, the same antimalarial drugs and mefloquine were tested with the following results: 9% (5 of 58) resistant to chloroquine; 2% (1 of 58) resistant to amodiaquine, and 3% (2 of 58) resistant to a combination of sulfadoxine/pyrimethamine. No isolates resistant to quinine or mefloquine were found. Effective concentrations (EC50, EC90, and EC99) and regression lines (log dose/response) for each antimalarial drug were calculated to establish a surveillance system for antimalarial drug chemosensitivity in Equatorial Guinea. Finally, 12 isolates from 12 patients previously treated with chloroquine were studied to compare both tests (in vivo-in vitro) and obtain a correlation between the RII and RIII types of in vivo and in vitro resistances. No correlation for the RI type was found between the two methods.

Ictal ECG changes in temporal lobe epilepsy

Changes in cardiac rhythm may occur during epileptic seizures and this has been suggested as a possible mechanism for sudden unexpected death amongst patients with chronic epilepsy (SUDEP). We have studied ECG changes during 61 complex partial seizures of temporal lobe origin in 20 patients. Tachycardia was observed in 24/61 (39%) and bradycardia in 3/61 (5%). The mean and median tachycardia rate was 139 and 140 beats/min (range 120-180). The longest R-R interval observed was 9 seconds. No difference was found in regard to the lateralisation of seizures and cardiac arrhytmia. One of the patients with bradycardia was fitted with a demand cardiac pacemaker, which appeared to decrease the number of his falls. In conclusion, ictal cardiac changes which may be seen in temporal lobe epilepsy (TLE) are sinus tachycardia and occasionally sinus bradycardia. Patients presenting vague complains suggestive of either TLE or cardiac dysrhythmia, simultaneous monitoring with EEG/ECG is required, and if the episodes are frequent, video-EEG should be considered. Further studies on this subject are warranted as this may shed some light on possible mechanisms for SUDEP.

YAC contigs covering an 8-megabase region of 3p deleted in the small-cell lung cancer cell line U2020

Somatic deletions of chromosome 3p occur at high frequencies in cancers of kidney, breast, cervix, head and neck, nasopharynx, and lung. The frequency of 3p deletion in lung cancer approaches 100% among small cell lesions and 70 to 80% in non-small cell lesions. This evidence strongly implies that one or more tumor suppressor genes of potentially widespread significance reside within the deleted region(s). Precise definition of the deleted target region(s) has been difficult due to the extensive area(s) lost and use of markers with low informativeness. However, improved definition remains essential to permit isolation of putative tumor suppressor genes from 3p. The identification of several small, homozygous 3p deletions in lung cancer cell lines has provided a critical resource that will assist this search. The U2020 cell line contains a small homozygous deletion that maps to a very proximal region of 3p and includes the marker D3S3. We previously identified a subset of DNA markers located within the deleted region and determined their relative order by pulsed-field gel mapping studies. In the present report, we describe the development of YAC contigs that span the majority of the deleted region and link up to flanking markers on both sides. The centromere proximal portion of the contig crosses the breakpoint from an X;3 translocation located within 3p12 providing both location and orientation to the map. PCR-based (CA)n microsatellite polymorphisms have been localized within and flanking the deletion region. These markers should greatly facilitate loss-of-heterozygosity studies of this region in human cancer. The contig provides a direct means for isolation of putative tumor suppressor genes from this segment of 3p.

Creative ritual in a hospice

St. Peter's Hospice, Albany, NY, is dedicated to meeting the emotional needs of patients, families, and staff. Creative ritual, hospice leaders have found, is a powerful tool that can: Provide an "arena" for healing, affirmation, reconciliation, and celebration Serve as a reminder of the sacred Evoke heartfelt emotion Effect renewal and inspiration Offer an opportunity to cleanse the soul of grief, anger, frustration, or guilt Provide tangible experiences of bonding and interdependence Prevent staff burnout St. Peter's staff show a good deal of imagination and variety in creating rituals. Possible themes include patients' birthdays or wedding anniversaries, religious celebrations, national holidays, and changes of seasons. A lighted candle, bouquet of flowers, or incense burner may be used to give the ritual a focus. Music is often played to help set the tone. Rituals involve a major shift in consciousness. They often allow participants to express feelings it would otherwise be difficult for them to put into words. At St. Peter's, participants may begin to communicate by sharing favorite prayers, poems, photos, or works of art. Or they may make music--the hospice provides the instruments--or pass around a Native American "talking stick." Such methods facilitate the bonding of patients and their families. Particularly important are those rituals which allow patients and estranged family members to reconcile. Others enable patients to acknowledge God-given gifts. Still other rituals are held for staff members, who thereby deal with the anger and sadness their work inevitably brings. For all at St. Peter's Hospice ritual is a source of healing, affirmation, renewal, inspiration, and grace.

Application and evaluation of QBC malaria diagnosis in a holoendemic area

Quantitative Buffy Coat Analysis was used in practical diagnosis situations. In the first place, sensitivity and specificity was measured in an active search survey (720 schoolchildren under 10 years of age, in nine field trips) under unfavourable laboratory conditions (onsite school diagnosis being conducted with electricity supplied by a diesel-powered generator). In this group, the QBC-based study revealed sensitivity and specificity ratings of 99.6% and 81.7% respectively. QBC proved 5.5% more sensitive than the thick-film method, but specificity was greater with the latter. QBC returned good results when used in adverse situations, viz., in the absence of air conditioning and with a diesel generator as the only power supply. QBC was used in a passive search survey (hospital group, 618 children) under good laboratory conditions (air conditioning) with patients enrolled in a trial to measure resistance to antimalarial drugs. In this survey we targeted at assessing the efficacy of chloroquine treatment at dose of 25 mg/kg/3 days. QBC proved more sensitive than the thick-film method, detecting - on day 14 of the in vivo test - low parasitaemias that had gone undetected by thick film. Lastly, this study reports on the conversion of QBC readings (parasitaemia per field) into thick-field terms (number of parasites per microliter of blood), with the aim of measuring the degree of recurring parasitaemia.