Rhabdomyolysis and HMG-CoA reductase inhibitors

OBJECTIVE

To review rhabdomyolysis and discuss the role of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) and their interactions with other agents in precipitating this condition, and to present case reports of statin-induced rhabdomyolysis.

DATA SOURCE

Relevant clinical literature was accessed using MEDLINE (January 1985-October 2000). The following search terms were used: rhabdomyolysis, adverse events, drug interactions, statins, and HMG-CoA reductase inhibitors.

DISCUSSION

Rhabdomyolysis occurs when extensive muscle damage results in the release of cellular contents into systemic circulation. Major complications include acute renal failure, cardiac abnormalities, and compartment syndrome. Treatment of rhabdomyolysis is supportive, with the primary aim of preventing renal and cardiac complications. Statin monotherapy or combination therapy may result in myopathy, which rarely progresses to rhabdomyolysis. The mechanism for drug interactions with the statins involves their property of lipid or water solubility. This characteristic determines the degree of hepatoenteric or renal metabolism of the statins. All statins except pravastatin undergo metabolism via the cytochrome P450 enzyme system. Other pharmacologic agents that are also metabolized via this pathway may interact with the statins and cause rhabdomyolysis. The risk of statin-induced rhabdomyolysis is increased significantly when statins are used concomitantly with such drugs as fibrates, cyclosporine, macrolide antibiotics, and azole antifungals.

CONCLUSIONS

Rhabdomyolysis is a rare but clinically important adverse event of statin monotherapy or combination therapy. Thorough understanding of this condition may help prevent or minimize adverse health outcomes in patents receiving statin therapy.

Evidence for a cochlear origin for acoustic re-emissions, threshold fine-structure and tonal tinnitus

Delayed acoustic waves have been measured in the sealed ear canal in response to click and tone-burst stimuli. The response shows compressive nonlinearity, evidence for 'active' processing, and frequency tuning. At low sound levels group and phase delays correspond, and represent about 15 waves delay for the mid-frequency region. Frequency positions of pressure peaks and dips for continous tone stimulation can be predicted from the phase delays and persist well below threshold. Fine-structure in the audiogram is also related to these irregularities. Hydrostatic pressure, induced by body tilt, can eliminate audiogram fine-structure and reve rse the positions of peaks and dips for inverted body positions. This is interpreted as due to changes of internal reflection from the middle ear caused by acoustic impedance changes. Tinnitus can be induced by this inverted body posture, can be measured objectively in certain cases, and demonstrates properties such as synchronisation and beating with an external signal. These findings support the view of Kemp that the phenomena of acoustic re-emission, threshold fine-structure, and tinnitus are interrelated and originate within the cochlea.

Nocardial infections in renal transplant recipients

Upon review of the English literature and the patients at our hospital, we identified 94 renal transplant recipients with nocardiosis. These patients were further evaluated and compared to nonrenal transplant patients with nocardiosis. We found that these patients were similar in presentation, course, and therapeutic outcome to non-transplant patients. Survival was related to underlying disease, site of infection, rapidity with which the diagnosis was made and, especially, the inclusion of a sulfa compound in the antimicrobial regimen. Transplant centers with high rates of Nocardia infection should consider trimethoprim/sulfamethoxazole prophylaxis for at least the first year after transplantation.

Current therapy for Crigler-Najjar syndrome type 1: report of a world registry

This study represents a multicenter survey on the management of patients with Crigler-Najjar syndrome (CNS) type 1. The aim of the survey was to find guiding principles for physicians in the care of these patients. Fifty-seven patients were included. At the time of inclusion, 21 patients had received a liver transplant (37%). The average age at transplantation was 9.1 +/- 6.9 years (range, 1-23 years); the age of the patients who had not been transplanted at the time of inclusion was 6.9 +/- 6.0 years (range, 0-23 years). Brain damage had developed in 15 patients (26%). Five patients died, and 10 are alive with some degree of mental or physical handicap. In 2 patients, ages 22 and 23 years, early signs of bilirubin encephalopathy could be reversed, in 1 by prompt medical intervention followed by liver transplantation and in the other by prompt liver transplantation. Seven patients underwent transplantation with some degree of brain damage at the time of the surgery; 1 of these died after retransplantation, 2 improved neurologically, and 4 remained neurologically impaired. The age of 8 patients with and 13 without brain damage at or before transplantation was 14.3 +/- 5.9 and 5.9 +/- 5.4 years (P < .01), respectively. Therapy of CNS type 1 consists of phototherapy (12 h/d), followed by liver transplantation. Phototherapy, although initially very effective, is socially inconvenient and becomes less efficient in the older age group, thus also decreasing compliance. Currently, liver transplantation is the only effective therapy. This survey shows that, in a significant number of patients, liver transplantation is performed after some form of brain damage has already occurred. From this, one must conclude that liver transplantation should be performed at a young age, particularly in situations in which reliable administration of phototherapy cannot be guaranteed.

Postoperative motility of the large intestine in man

Motor activity of the colon in the immediate postoperative period has been studied in human subjects using radiotelemetering capsules, radioopaque markers and serial abdominal radiographs. Following operations outside the abdomen there is a delay of about 16 hours before colonic activity returns. After abdominal operations the delay is from 40 to 48 hours. The length of an operation has no significant effect upon the duration of colonic ileus. The amount of postoperative analgesia has no significant effect upon the duration of colonic ileus. Gaseous distension after laparotomy is confined to the colon.

Model for cochlear echoes and tinnitus based on an observed electrical correlate

Experiments in cat have revealed evidence of temporal correspondence between round-window recorded electrical potentials and delayed acoustical responses in the sealed ear canal at low sound levels. This would be difficult to explain if the acoustic response contained an appreciable component of delay due to a reverse travelling wave. An alternative interpretation is offered in which outer hair cells are assumed to undergo periodic volumetric changes correlated with their electrochemical activity. These volume changes would act on, and be divided between, the oval window, giving acoustic reemission and the basilar membrane, giving a secondary travelling wave. Owing to the active nature of the hair cell, the output is potentially greater than the input, so that when the secondary travelling wave exceeds the initial one, the amplitude will build up and continuous oscillation occurs, giving 'tinnitus'.

Nifedipine: kinetics and hemodynamic effects in patients with liver cirrhosis after intravenous and oral administration

The pharmacokinetics and hemodynamic effects of nifedipine were studied in patients with liver cirrhosis and in age-matched healthy control subjects. In a randomized order each subject received nifedipine by intravenous infusion (4.5 mg in 45 minutes) and as a tablet (20 mg). After intravenous nifedipine patients had a longer elimination t1/2 (420 +/- 254 vs. 111 +/- 22 minutes; P less than 0.01), a greater volume of distribution (1.29 +/- 0.60 vs. 0.97 +/- 0.42 L/kg), and a lower systemic clearance (233 +/- 109 vs. 588 +/- 140 ml/min; P less than 0.001). Plasma protein binding of nifedipine was lower in the patients (P less than 0.001). After oral nifedipine systemic availability was much higher in patients (90.5% +/- 26.2% vs. 51.1% +/- 17.1%; P less than 0.01) and maximal in patients with a portacaval shunt. Blood pressure decreased and heart rate increased after intravenous nifedipine and these effects could be fitted to plasma concentrations by a sigmoidal model. Maximal effects on heart rate and diastolic blood pressure were not different in liver cirrhosis. When free drug levels were considered, the concentrations corresponding to half the maximal effect were also not different. Blood pressure changes with oral nifedipine were comparable with those after intravenous infusion. We conclude that in patients with liver cirrhosis the pharmacokinetics of nifedipine are considerably altered; dose reduction is recommended when such patients need oral nifedipine.

Saphenous vein aortorenal bypass grafts: Serial arteriographic study

One-hundred and eight autologous saphenous veins were used to construct an aortorenal bypass in 94 patients and were followed from five months to nine years. There were three operative deaths. Twelve grafts thrombosed. In seven patients the thrombosis was demonstrated in the early postoperative period. In the other five patients an early postoperative arteriogram was not done, the thrombosis was first demonstrated arteriographically 4(1/2)-9 months following operation. In the latter patients it is impossible to determine when the thrombosis occurred. No graft demonstrated to be patent in the early postoperative period was subsequently found to be thrombosed. Therefore it is likely that almost all thromboses occurred in the immediate postoperative period and were the result of technical errors in the arterial reconstruction. A total of 130 followup arteriograms were done in 75 patients with 89 patent grafts. Long term, serial followup arteriograms were done in 29 patients with 39 vein grafts. Three different patterns were observed: 1) the vein graft maintained its initial size and configuration (62%); 2) the vein graft underwent uniform dilatation throughout its length (20%); and 3) the dilatation progressed to aneurysmal proportions (5%). Significant suture line stenosis developed in one patient who also had recurrent renovascular hypertension. Progression of severity of "apparently insignificant" stenosis or development of a new lesion in the contralateral renal artery was observed in 12 of the 29 patients (41%). These patients serve to emphasize the fact that nephrectomy is ill-advised in patients with renovascular hypertension except under the most demanding circumstances. Finally, there is an urgent need for a careful comparative study of the grafts that are currently being used to construct aortorenal bypasses.

Cochlear tuning properties: concurrent basilar membrane and single nerve fiber measurements

Removal of perilymph from the cochlea has been reported to destroy the sharp tuning of cochlear neurons. That these changes are mechanical in origin is refuted by the concurrent recording of sharp neural tuning with broad basilar membrane responses from the same region of the partially drained cat cochlea. A second cochlear filter is therefore necessary.

Resistance to extinction of conditioned odor perceptions: evaluative conditioning is not unique

A tasteless odor will smell sweeter after being sampled by mouth with sucrose and will smell sourer after being sampled with citric acid. This tasty-smell effect was found in experiments that compared odor-taste and color-taste pairings. Using odors and colors with minimal taste (Experiment 1), the authors found that repeated experience of odor-taste mixtures produced conditioned changes in odor qualities that were unaffected by intermixed color-taste trials (Experiment 2). An extinction procedure, consisting of postconditioning presentations of the odor in water, had no detectable effect on the changed perception of an odor (Experiments 3 and 4). In contrast, this procedure altered judgments about the expected taste of colored solutions. Evaluative conditioning (conditioned changes in liking) is claimed to be resistant to extinction. However, these results suggest that resistance to extinction in odors is related to the way they are encoded rather than to their hedonic properties.

Duty-related stressors and PTSD symptoms in suburban police officers

This study examined the effects of duty-related stress on police officers. Using a sample of 100 suburban police officers, an anonymous questionnaire requested demographic information and included a measure of duty-related stressors, SCL-90-R, the Posttraumatic Stress Disorder scale of the Impact of Events Scale-Revised, and a locus of control scale. Also assessed was whether Critical Incident Stress Debriefing was experienced. The results showed significant correlations between scores on duty-related stress, somatization, and symptoms of PTSD. 13% of the sample met the DSM-IV (1994) diagnostic criteria for PTSD. Results of the regression analysis showed the best predictors for the diagnosis of PTSD were associated with the factor of Exposure to Death and Life Threat, which corresponds to the DSM-IV AI criteria. Finally, 63% of the respondents stated that a critical incident debriefing would be beneficial following an extremely stressful event related to duty.

The medical status of methadone maintenance patients in treatment for 11-18 years

To assess the safety and potential health consequences of long-term methadone maintenance treatment, we identified 111 male patients admitted to methadone maintenance treatment between 1965 and 1968, still enrolled in 1980 and in continuous treatment for at least 10 years. We were able, between 1980 and 1985, to examine patients or review records of 110 patients (99%). Most medical diagnoses, symptomatic complaints, physical examination findings and laboratory test results occurred with similar frequency in the long-term methadone maintenance patients and in a group of 56 long-term heroin addicts. These data suggest that prolonged methadone maintenance treatment is safe and is not associated with unexpected adverse effects.

Reduction of plasma renin activity by inhibition of the fatty acid cyclooxygenase in human subjects: independence of sodium retention

We carried out the present studies to determine whether the suppression of plasma renin activity (PRA) that follows inhibition of prostaglandin (PG) synthesis can be dissociated from the sodium-retaining effects of these drugs. In an initial investigation we studied the effect of indomethacin on PRA in normal subjects in balance on a 10 mM Na+ diet to prevent Na+ retention. Under these experimental conditions indomethacin did not lower PRA even though the fatty acid cyclooxygenase was inhibited, as indicated by a greater than 70% reduction in the major urinary metabolite of prostaglandin E (PGE-M). Sodium depletion leads to enhanced sympathetic activity. We therefore studied the effect of indomethacin on a group of subjects in 10 mM Na+ balance in whom the effect of increased beta-sympathetic activity was blocked by the administration of propranolol. In this group, indomethacin caused 65% suppression of PGE-M and had no effect on Na+ balance, but reversibly reduced PRA in the supine and upright positions by 84% and 70%, respectively. In normal subjects in 10 mM Na+ balance, the isoproterenol-induced increase in PRA also was unaffected by indomethacin. These data establish that inhibition of the cyclooxygenase can result in a reduction of PRA that is independent of changes in Na+ balance or beta-sympathetic tone.

Weight loss and elevated gluconeogenesis from alanine in lung cancer patients

BACKGROUND

The role of gluconeogenesis from protein in the pathogenesis of weight loss in lung cancer is unclear.

OBJECTIVE

Our aim was to study gluconeogenesis from alanine in lung cancer patients and to analyze its relation to the degree of weight loss.

DESIGN

In this cross-sectional study, we used primed-constant infusions of [6,6-(2)H(2)]-D-glucose and [3-(13)C]-L-alanine to assess whole-body glucose and alanine turnover and gluconeogenesis from alanine in weight-losing (WL, n = 9) and weight-stable (WS, n = 10) lung cancer patients and healthy control (n = 15) subjects.

RESULTS

Energy intake and plasma alanine concentrations did not differ significantly among the subject groups. Mean (+/-SEM) whole-body glucose production was significantly higher in WL than in WS and control subjects (0.74 +/- 0.06 compared with 0.55 +/- 0.04 and 0.51 +/- 0.04 mmol*kg(-)(1)*h(-)(1), respectively, P < 0.01). Alanine turnover was significantly elevated in WL compared with WS and control subjects (0.57 +/- 0.04 compared with 0.42 +/- 0.05 and 0.40 +/- 0.03 mmol*kg(-)(1)*h(-)(1), respectively, P < 0.01). Gluconeogenesis from alanine was significantly higher in WL than in WS and control subjects (0.47 +/- 0.04 compared with 0.31 +/- 0.04 and 0.29 +/- 0.04 mmol*kg(-)(1)*h(-)(1), respectively, P < 0.01). The degree of weight loss was positively correlated with glucose and alanine turnover and with gluconeogenesis from alanine (r = 0.45 for all, P < 0.01).

CONCLUSIONS

Aberrant glucose and alanine metabolism occurred in WL lung cancer patients. These changes were related to the degree of weight loss and not to the presence of lung cancer per se.

Saralasin infusion in the recognition of renovascular hypertension

Saralasin, an angiotensin II antagonist, was infused into 49 patients with renal artery stenosis, 10 patients with essential hypertension and normal renal arteriograms, and five patients with "low-renin essential hypertension." Renal venous renin and differential renal function studies were used to assess the functional significance of arterial stenoses. "Response" to saralasin, evidenced by a fall in blood pressure during infusion, occurred in no patients with "low renin" hypertension and in only 20% of patients with normal renal arteriograms. In contrast, saralasin "response" occurred in more than 80% of patients with renal artery stenosis and lateralizing functional studies and 100% of cases of "proven" renovascular hypertension (cure or improvement of hypertension after operative treatment). We suggest that saralasin infusion might be a valuable screening test for the recognition of renovascular hypertension.

Parenteral benzyl alcohol-induced hypersensitivity reaction

An uncommon hypersensitivity reaction due to parenteral benzyl alcohol administration is reported. One patient treated with benzyl alcohol-preserved cytarabine, vincristine, and heparin solutions developed a systemic hypersensitivity reaction on three separate occasions. Hypersensitivity to benzyl alcohol was confirmed by skin testing. Clinically, the patient presented with a fever and a maculopapular rash on the chest and arms. None of the reactions were life-threatening or required hospitalization of the patient.

Animal models of tinnitus

There are few physiological data available on the origin and nature of tinnitus. It is not even known whether tinnitus associated with cochlear pathology is a manifestation of increased or decreased activity in the cochlear nerve. In previous investigations of cochlear pathology, the spontaneous neural activity has generally been found to be depressed. In the present experiments, an animal model has been established by the administration of sodium salicylate in doses producing blood concentrations that evoke tinnitus in humans. Under these conditions, changes occur in cochlear nerve-fibre thresholds and tuning, similar to those obtained in other types of cochlear pathology. However, under salicylate, the distribution of spontaneous discharge shifts significantly to higher rates than normal. These changes are accompanied in some, but not all, fibres by changes in the temporal patterns of discharge suggestive of excitation. In the second animal model studied, a normal guinea-pig that had a naturally occurring continuous tonal emission, analogous to that recently recorded in human "physiological" tinnitus, was investigated in detail. The emitted signal was recorded in the ear-canal acoustic pressure and in the round-window potential. Several lines of evidence point to the signal as being cochlear in origin, including: its resistance to muscular paralysis and section of the stapedius muscle; the effects of changes in middle-ear pressure; its reversible elimination by hypoxia; and its suppression by tones of higher frequency.

Patterns of antihypertensive use among patients in the US Department of Defense database initially prescribed an angiotensin-converting enzyme inhibitor or calcium channel blocker

The US Department of Defense recently assembled electronic records of outpatient prescriptions dispensed through the Uniformed Services Prescription Database Project (USPDP) going back to 1990. The objectives of this portion of a larger study were: (1) to examine longitudinally the patterns of antihypertensive drug use during the first year of therapy in patients whose initial therapy was with an angiotensin-converting enzyme (ACE) inhibitor or a calcium channel blocker (CCB); (2) to determine continuous and noncontinuous users of antihypertensive drugs; and (3) to estimate the direct medication costs for each pattern of medication use. Filtering criteria for patient and prescription identification were developed, because the USPDP contains no records of confirmatory diagnoses of hypertension. Once data filters were implemented, information for 771 patients was analyzed. An ACE inhibitor was the initial therapy for 328 patients, accounting for 1935 antihypertensive medication prescription fills, and a CCB was the initial therapy for 443 patients, accounting for 2459 fills (including refills). Slightly more than half of the patients (n = 401, 52.0%) were classified as continuous users (> or = 80% medication-possession ratio [supply of medication in days divided by the number of days in the 12-month study period]). In the first year, 177 of these continuous users (44.1%) had no change in therapy in the first year, 49 (12.2%) had an increase in dose, 8 (2.0%) had a decrease in dose, 15 (3.7%) had a change to a different therapeutic class of antihypertensive medication, 14 (3.5%) were changed to a different medication in the same therapeutic class, 20 (5.0%) had a new medication added to the regimen, and 118 (29.4%) had complex regimens involving more than one change. For continuous users, the mean medication supply in days was 354.6, and the average time before a medication change was 152.1 days for those continuous users who had one change in therapy. The overall average wholesale price (AWP) and average manufacturer price (AMP) for continuous users during 1 year of therapy were $471.31 and $378.51, respectively. For those patients whose therapy was changed to an ACE inhibitor/CCB combination and who were continuous users, the average AWP was $598.47 per year ($492.05 AMP). Once the change from monotherapy to an ACE inhibitor/CCB combination occurred in continuous users, AWP costs per member per month increased by approximately $22.00 ($18.00 AMP). Over half of the patients whose initial therapy was an ACE inhibitor or CCB had at least one change in their first year of therapy. Research into the reasons for these changes and their outcomes is needed.

Host-specific Variation in Infection by Toxigenic Fungi and Contamination by Mycotoxins in Pearl Millet and Corn

Pearl millet is widely consumed in regions of Africa and Asia, and is increasingly being grown as an alternative grain in drought-prone regions of the United States. Pearl millet and corn were grown in dryland conditions at Tifton, Georgia, USA and grains were compared for pre-harvest infection by potentially toxigenic fungi and contamination by mycotoxins. Corn hybrids Agripro 9909 and Pioneer 3146, and pearl millet Tifgrain 102 were grown in 2000 and 2001; pearl millet HGM 100 was included in the test in 2001. Hybrids were sown on multiple planting dates in each year to induce variation in flowering time. Host species differed in the frequency of isolation of potentially toxigenic fungal species in both years. Across years, corn hybrids were more prone to infection by Aspergillus flavus Link (maximum isolation frequency = 8.8%) and Fusarium moniliforme Sheldon sensu lato (maximum isolation frequency = 72.8%), with corresponding greater concentrations of aflatoxins (maximum concentration = 204.9 microg kg(-1)) and fumonisins (maximum concentration = 34,039 microg kg(-1)). Pearl millet was more prone to infection by F. semitectum Berk. & Ravenel (maximum isolation = 74.2%) and F. chlamydosporum Wollenweb & Reinking (maximum isolation = 33.0%), and contamination by moniliformin (maximum contamination = 92.1 microg kg(-1)). Beauvericin (maximum concentration = 414.6 microg kg(-1)) was present in both hosts. Planting date of corn affected aflatoxin and beauvericin contamination in 2000, and fumonisin concentration in 2001. The observed differences in mycotoxin contamination of the grains, which are likely due to host-specific differences in susceptibility to pre-harvest mycoflora, may affect food safety when the crops are grown under stress conditions.

Living near a freeway is associated with lower bone mineral density among Mexican Americans

We hypothesized that chronic exposures to traffic combustion products may lower bone mineral density (BMD). We found that proximity to freeways was associated with reduced BMD. Our findings suggest that traffic-related pollution may contribute to the occurrence of osteopenia and osteoporosis.

INTRODUCTION

Adults residing in rural areas have been linked with higher BMD. We aimed to determine if this difference is due in part to air pollution by examining the relationships between traffic metrics and ambient air pollution with total body and pelvic BMD.

METHODS

Mexican American adults (n = 1,175; mean 34 years; 72 % female) who had participated in the BetaGene study of air pollution, obesity, and insulin resistance were included in this analysis. Total body and pelvic BMD were estimated using dual-energy X-ray absorptiometry. Traffic and ambient air pollutant exposures were estimated at residences using location and ambient monitoring data. Variance component models were used to analyze the associations between residential distance to the nearest freeway and ambient air pollutants with BMD.

RESULTS

Residential proximity to a freeway was associated with lower total body BMD (p-trend = 0.01) and pelvic BMD (p-trend = 0.03) after adjustment for age, sex, weight, and height. The adjusted mean total body and pelvic BMD in participants living within 500 m of a freeway were 0.02 and 0.03 g/cm(2) lower than participants living greater than 1,500 m from a freeway. These associations did not differ significantly by age, sex, or obesity status. Results were similar after further adjustment for body fat and weekly physical activity minutes. Ambient air pollutants (NO2, O3, and PM2.5) were not significantly associated with BMD.

CONCLUSIONS

Traffic-related exposures in overweight and obese Mexican Americans may adversely affect BMD. Our findings indicate that long-term exposures to traffic may contribute to the occurrence of osteoporosis and its consequences.

Stages of decompensation in combat-related posttraumatic stress disorder: a new conceptual model

This conceptual article presents a model of severe, chronic combat-related PTSD based on several years of longitudinal clinical observations of Vietnam veterans. The model describes a repeating cycle of decompensation that profoundly disrupts the veteran's life. There appear to be "stages" of decompensation that can be described clinically and may be distinct physiologically. The stages describe a wide range of functioning, from adaptive to totally dysfunctional PTSD core symptoms, as well as several other dimensions of clinical functioning, such as affect regulation, defenses, ego states, interactions with the environment, capacity for self-destruction/suicide and capacity for attachment and insight are described for each stage. Clinical and research implications are discussed.

Fusarium species of the Gibberella fujikuroi complex and fumonisin contamination of pearl millet and corn in Georgia, USA

This study was designed to identify and compare the Fusarium species of the Gibberella fujikuroi complex on pearl millet (Pennisetum glaucum (L.) R. Br) and corn (Zea mays L.) crops grown in southern Georgia, and to determine their influence on potential fumonisin production. Pearl millet and corn samples were collected in Georgia in 1996, 1997 and 1998. Three percent of the pearl millet seeds had fungi similar to the Fusarium species of the G. fujikuroi species complex. One hundred and nineteen representative isolates visually similar to the G. fujikuroi species complex from pearl millet were paired with mating population A (Fusarium verticillioides (Sacc.) Nirenberg), mating population D (F. proliferatum (Matsushima) Nirenberg) and mating population F (F. thapsinum (Klittich, Leslie, Nelson and Marasas) tester strains. Successful crosses were obtained with 50.4%, 10.1% and 0.0% of these isolates with the A, D and F tester strains, while 39.5 of the isolates did not form perithecia with any tester strains. Two of the typical infertile isolates were characterized by DNA sequence comparisons and were identified as Fusarium pseudonygamai (Nirenberg and O'Donnell), which is the first known isolation of this species in the United States. Based on the pattern of cross-compatibility, conidiogenesis, colony characteristics and media pigmentation, a majority of the infertile isolates belong to this species. Fumonisins FB(1) and FB(2) were not detected in any of the 81 pearl millet samples analyzed. The species of the G. fujikuroi species complex were dominant in corn and were isolated from 84%, 74% and 65% of the seed in 1996, 1997 and 1998, respectively. Representative species of the G. fujikuroi species complex were isolated from 1996 to 1998 Georgia corn survey (162, 104 and 111 isolates, respectively) and tested for mating compatibility. The incidence of isolates belonging to mating population A (F. verticillioides) ranged from 70.2% to 89.5%. Corn survey samples were assayed for fumonisins, and 63% to 91% of the 1996, 1997 and 1998 samples were contaminated. The total amount of fumonisins in the corn samples ranged from 0.6 to 33.3 microg/g.

Mechanics of the basilar membrane in Caiman crocodilus

Vibration measurements were made at a number of positions near the proximal (basal) end of the basilar membrane, and on the columella footplate, of Caiman crocodilus using a capacitive probe. The measurements established the existence of a mechanical travelling wave in this species. They showed no significant change of mechanical tuning with temperature, and were highly significantly different from previous reports of neural temperature sensitivity (Smolders, J. and Klinke, R. (1984): J. Comp. Physiol. 155, 19-30). Thus the neural sensitivity to temperature change appears not to depend upon basilar membrane mechanics. One interpretation of this is that the basilar membrane passively precedes an active temperature-sensitive filter. It was also found that the limbus supporting the basilar membrane had a measurable, but unturned, vibration and that the effect of draining scala tympani for the measurements was to increase the basilar membrane tuning frequency by a factor of about 1.5.