Factors related to the survival of papillary and follicular thyroid carcinoma patients with distant metastases

There is limited clinical information comparing presentations and results of treatment of papillary and follicular thyroid carcinoma patients with distant metastases. We retrospectively analyzed data of 1,257 thyroid cancer patients who received their treatment and follow-up at Chang Gung Memorial Hospital. We found 992 patients with papillary carcinoma and 205 patients with follicular thyroid carcinoma. Of these, 68 patients with papillary thyroid carcinoma (6.9%) had distant metastases at the time of diagnosis or during the follow-up period. Of the follicular thyroid carcinoma patients, 69 (33.7%) had distant metastases. Of the 68 patients with papillary carcinoma, only 33 were categorized as stage IV at the time of diagnosis. Nine of the patients were categorized as clinical stage I carcinoma, 10 as stage II, and 16 as stage III. Sixteen patients (23.5%) died during the study period, all but 2 of thyroid cancer. Twelve of the 68 patients were disease-free after treatment. Of the 69 patients with follicular thyroid carcinoma, 58 were categorized as stage IV at the time of diagnosis. Six of the patients were categorized as clinical stage I carcinoma, 2 as stage II, and 3 as stage III at the time of diagnosis; all of these patients deteriorated to stage IV during the follow-up period. Of the 42 patients with follicular thyroid carcinoma involving bone, 24 presented with bone metastases during the initial diagnosis. After treatment, 25 of 69 patients with follicular carcinoma died of follicular carcinoma. Only 3 patients were disease-free after the treatment. In patients with follicular carcinoma, only tumor size was an important prognostic factor. In this study, 8 patients categorized as clinical stages I to III at the time of operation had thyroglobulin (Tg) levels less than 5 ng/mL and developed distant metastases during the follow-up period. In conclusion, at diagnosis a large group of Asian patients with metastatic well-differentiated thyroid cancer was more likely to have follicular than papillary histology, and that, as expected, metastases from follicular cancer were present earlier and more frequently, were more likely to involve bone, were more likely to be associated with mortality, and were linked to tumor size but not gender. Also unlike some other reports, treatment producing a low Tg did not always produce a good outcome. More aggressive surgical procedures may be able to improve outcomes.

Riedel's thyroiditis associated with follicular carcinoma

Riedel's thyroiditis is an uncommon disorder of unknown etiology that is characterized by an invasive fibrotic process that partially destroys the gland and extends into adjacent neck structures. Its clinical manifestation as a stony-hard, poorly defined enlargement over the thyroid gland and local compression of the trachea, esophagus and recurrent laryngeal nerve can mimic invasive thyroid carcinoma. Because Riedel's thyroiditis is a self-limiting disease, its management should be conservative. However, invasive cancer such as follicular carcinoma can occur in association with Riedel's thyroiditis. Such a concurrence completely changes the focus of management. We report a case of Riedel's thyroiditis that was found in a patient with a follicular carcinoma. The strategy of management is discussed together with a review of the relevant literature.

A(2A) adenosine receptor deficiency attenuates brain injury induced by transient focal ischemia in mice

Extracellular adenosine critically modulates ischemic brain injury, at least in part through activation of the A(1) adenosine receptor. However, the role played by the A(2A) receptor has been obscured by intrinsic limitations of A(2A) adenosinergic agents. To overcome these pharmacological limitations, we explored the consequences of deleting the A(2A) adenosine receptor on brain damage after transient focal ischemia. Cerebral morphology, as well as vascular and physiological measures (before, during, and after ischemia) did not differ between A(2A) receptor knock-out and wild-type littermates. The volume of cerebral infarction, as well as the associated neurological deficit induced by transient filament occlusion of the middle cerebral artery, were significantly attenuated in A(2A) receptor knock-out mice. This neuroprotective phenotype of A(2A) receptor-deficient mice was observed in different genetic backgrounds, confirming A(2A) receptor disruption as its cause. Together with complimentary pharmacological studies, these data suggest that A(2A) receptors play a prominent role in the development of ischemic injury within brain and demonstrate the potential for anatomical and functional neuroprotection against stroke by A(2A) receptor antagonists.

Identification of familial hypercholesterolemia in Taiwan: report of eleven cases

BACKGROUND

Familial hypercholesterolemia is associated with a very high risk of premature coronary heart disease. In order to identify cases of familial hypercholesterolemia in Taiwan, we screened the hyperlipidemic patients in our metabolic clinics.

METHODS

Hyperlipidemic patients were screened in the metabolic outpatient department and the cases which fulfilled the clinical criteria of definitive or possible familial hypercholesterolemia were further analyzed. Their clinical characteristics, including age, gender, physical findings, past history of coronary heart disease or cerebrovascular accident (CVA), family history, and lipid profiles before and after medical treatment, were reviewed.

RESULTS

Eight women and 3 men fulfilled the diagnostic criteria. The mean age at diagnosis was 51.1 +/- 11.9 years old. Tendon xanthomas were found in 5 patients with definitive familial hypercholesterolemia. Coronary heart disease was confirmed in one patient and old CVA was noted in another 2 patients. The mean total cholesterol level was 390.3 +/- 88.9 mg/dl and the mean low density lipoprotein-cholesterol (LDL-cholesterol) level was 309.6 +/- 89.9 mg/dl before treatment. After a mean treatment duration of 45.2 months, the mean total cholesterol level and LDL-cholesterol level were 326.8 +/- 87.8 mg/dl and 249.1 +/- 91.1 mg/dl, respectively.

CONCLUSION

Clinically diagnosed familial hypercholesterolemia indeed exists in Taiwan. As compared to other reports, the mean age at diagnosis in our series was older and the majority of patients were women. Most patients were not vigorously treated and the family members were not thoroughly screened. Adequate treatment of patients with familial hypercholesterolemia in clinical practice and screening their family members are crucial in preventing new or recurrent coronary heart disease.

The induction of liver microsomal cytochrome P450 by Glycyrrhiza uralensis and glycyrrhetinic acid in mice

The effect of Glycyrrhiza uralensis Fisch (GRZ) aqueous extract and one of its active principles Glycyrrhetinic acid (GRT) on hepatic cytochrome P450 in mice were investigated. Oral administration of GRZ at 10 g/kg/d or GRT at 50 mg/kg/d for 7 days was found to increase the P450 contents up to 4.6 fold compared with the controls. The activities of aryl hydrocarbon hydroxylase (AHH, 3.1 and 3.3 fold), aminopyrine N-demethylase (ADM, 4.2 and 3.2 folds), and 7-ethoxycumarin O-deethylase (ECOD, 2.8 and 2.5 fold) were also shown to be increased. Western blot analysis showed that the subtypes of P450 isoforms induced selectively by GRZ and GRT included CYP1A1 (1.8 and 1.5 fold over that of the control, respectively), CYP2B1 (both 1.3 fold), and CYP2C11 (3.2 and 3.0 fold). Moreover, significant positive correlation between the P450 content or the isoforms and the corresponding enzyme activities mentioned above was observed.

Intervening attenuation affects first-order statistical properties of ultrasound echo signals

Previous studies show that first-order statistical properties of ultrasound echo signals are related to the effective number of scatterers in the "resolution cell" of a pulse-echo ultrasound system. When the effective number of scatterers is large (~10 or more) this results in echo signals whose amplitude follows a Rayleigh distribution, with the RF echo signal obeying Gaussian statistics; deviation from Rayleigh or Gaussian statistics yields information on scatterer number densities. In this paper, the influence of the medium's attenuation on non-Gaussian properties of the echo signal is considered. Preferential attenuation of higher frequency components of a pulsed ultrasound beam effectively broadens the beam and increases the resolution cell size. Thus, the resultant non-Gaussian parameter for broad bandwidth excitation of the transducer depends not only on the scatterer number density but also on the attenuation in the medium. These effects can be reduced or eliminated by using narrow-band experiments.

Estimating the spatial autocorrelation function for ultrasound scatterers in isotropic media

The autocorrelation function pertaining to spatial distributions of ultrasonic scatterers in soft tissue is believed to contain useful information related to tissue morphology. A simple processing method applied to radio-frequency echo signals estimates this function for a sample having isotropic scattering conditions. It utilizes backscattered echo signals from the sample and echo signals from a reference object having defined scattering properties. The ratio of the echo signal power spectrum from the sample to the echo signal power spectrum from the reference object is obtained, and corrected for attenuation differences between the two media. This yields a "form factor" for the sample, whose inverse Fourier transform is the autocorrelation function. The method was tested using tissue-mimicking samples for which spatial autocorrelation functions could be modeled from the dimensions of embedded scatterers. The shapes of the measured autocorrelation functions were in reasonable agreement with those estimated, although measured functions overestimated the function at small lag distances. Scatterer diameters estimated from the zeros of the autocorrelation function agreed to within 6% of expected values when the measurement system bandwidth satisfied minimal criteria.

Nasopharyngeal carcinoma presenting as an intracranial abscess

BACKGROUND

There are many conditions related to brain abscess. Brain abscesses resulting from nasopharyngeal carcinoma is rare. It is unusual for an intracranial abscess to appear as the initial clinical presentation of nasopharyngeal carcinoma.

CASE REPORT

A 43-year-old male patient suffering from nasopharyngeal carcinoma with the initial manifestation of an intracranial abscess without symptoms and signs suggestive of the primary nasopharyngeal carcinoma is reported. The diagnosis was particularly elusive and was not made until the third admission.

CONCLUSION

Although it is rare, intracranial abscess should be considered as one of the possible manifestations of nasopharyngeal carcinoma.

Effect of infection brain edema on NMDA receptor binding in rat brain in vivo

The purpose of this study was to determine the effect of infection brain edema (IBE) in the rat model induced by injecting pertussis bacilli (PB) into the left carotid artery. The specific binding of N-methyl-D-aspartate (NMDA) receptor with [3H] MK-801 was measured in the neuronal membrane of cerebral cortex. The Scatchard plots were performed. The Bmax values were 0.623 +/- 0.082 and 0.606 +/- 0.087 pmol/mg protein in the group that received normal saline (NS) and PB respectively (P < 0.05). The Kd values were 43.1 +/- 4.2 and 30.5 +/- 3.0 nM in the groups NS and PB respectively. The results indicated that the affinity of NMDA receptor was significantly higher in the group PB than group NS, whereas the total number of NMDA receptors had not changed in the IBE model. The increase of affinity of NMDA receptor can be blockaded by MK-801 pretreatment in vivo.

Glomerular transforming growth factor-beta1 mRNA as a marker of glomerulosclerosis-application in renal biopsies

As transforming growth factor-beta1 (TGF-beta1) is implicated in the pathogenesis of glomerulosclerosis, the aim of the study was to demonstrate if levels of glomerular TGF-beta1 mRNA in renal biopsies correlated with glomerulosclerosis. Glomeruli were collected by microdissection from renal biopsies in patients with membranous nephropathy, lupus nephritis, diabetic nephropathy, minimal change disease and IgA nephropathy presented by proteinuria when serum creatinine was <3 mg%. Glomerular mRNAs were reverse transcribed and TGF-beta1, alpha2(IV) collagen, beta-actin cDNA quantitated by competitive polymerase chain reaction (PCR). By semiquantitative electron microscopy, a 3.5-fold increase of glomerular TGF-beta1/beta-actin mRNA ratio in the moderate sclerotic group (n = 23, p < 0.01) and a 1.5-fold increase in the mild sclerotic group (n = 22, p < 0.05) were observed when compared to the minimal sclerotic group (n = 12). A concordant increase of glomerular alpha2(IV) collagen mRNA was found with 2.2- and 1.3-fold in moderate and mild sclerotic groups, respectively. The TGF-beta1/beta-actin mRNA ratios were highest in membranous nephropathy (466.4 +/- 133.4, n = 11), followed by lupus nephritis (394.9 +/- 94.8, n = 12) and diabetic nephropathy (333.2 +/- 97.6, n = 10). Patients with minimal change disease(233.1 +/- 54.1, n = 15)and IgA nephropathy(185.3 +/- 39.6, n = 9) had low levels. The degree of glomerulosclerosis in each group followed the TGF-beta1/beta-actin mRNA ratios indicating that the level is the major determinant ofglomerulosclerosis but not the disease entities. Glomerular TGF-beta1/beta-actin mRNA ratio did not correlate with clinical parameters such as the urinary protein excretion and creatinine clearance. These results suggest that glomerular TGF-beta1/beta-actin mRNA ratio may be used as a marker of glomerulosclerosis in renal biopsy to reflect the local sclerotic process.

Correlation of fine needle aspiration cytology and frozen section biopsies in the diagnosis of thyroid nodules

AIMS

To evaluate the correlation of fine needle aspiration (FNA) cytology and frozen section biopsy in the diagnosis of thyroid nodules.

METHODS

The medical records of 662 patients who underwent FNA cytology of the thyroid and thyroid surgery were analysed. Frozen section biopsies were taken from 586 of the 662 patients. The diagnostic correlations of FNA cytology, frozen section, and both FNA cytology and frozen section with definitive histological assessment were evaluated.

RESULTS

Among the 662 patients who received FNA cytology, there were 356 cases (53.8%) diagnosed as benign, 114 cases (17.2%) as malignant, 148 cases (22.4%) as indeterminate, and 44 cases (6.6%) as unsatisfactory. The positive predictive value for the detection of malignancy by FNA cytology was 92.1% and the negative predictive value was 95.2%. The incidence of malignancy in the indeterminate cytological diagnosis was 23%. The diagnosis from frozen sections was benign in 445 cases (75.9%), malignant in 134 cases (22.9%), and deferred in 7 cases (1.2%). By frozen section, the positive and negative predictive values were 97% and 95.5%, respectively. Diagnostic accuracy up to 98% was achieved when FNA cytology and frozen section diagnoses were in agreement. No false positives were observed when FNA cytology and frozen sections were both positive for malignancy. When FNA cytology and frozen section diagnoses were discordant, frozen section showed a higher accuracy (78.9%) than FNA cytology (21.1%). In the face of an indeterminate or unsatisfactory cytological diagnosis, the diagnostic accuracy of frozen sections reached 92.6%.

CONCLUSIONS

The results confirm that FNA cytology is a useful tool in the initial evaluation of thyroid nodules. Intraoperative frozen section is a valuable procedure to confirm the cytological diagnosis and identify malignancy in patients with indeterminate or unsatisfactory cytological diagnosis. With reliance on frozen sections as an intraoperative guide of thyroid surgery, the possibility of unnecessary extensive surgery and the need for the second operation are considerably lower.

False-positive whole-body iodine-131 scan due to intrahepatic duct dilatation

Focal retention of radioactivity in the liver on whole-body 131I scan was interpreted as a metastatic lesion in a patient with well-differentiated thyroid cancer. Intrahepatic duct dilatation, usually resulting from biliary tract obstruction by bile stone, is a common disorder and may cause bile stasis. A patient with papillary thyroid cancer and a previous history of biliary tract stones had focal retention of radioactivity in the liver on whole-body 131I scan. Abdominal CT, endoscopic retrograde cholagiopancreatography, radionuclide cholangiography and sequential 131I scans demonstrated that this focal retention of radioactivity was caused by intrahepatic duct dilatation. Focal retention of radioactivity is visualized on delayed images but not on early images. The radioactivity initially increases and then decreases on following days.

[Suppressive effects of a plant-origin polyol, dulcitol on collagen-induced arthritis in mice]

Dulcitol was isolated chemically from Celastrus obiculatus Thumb and determined by HPLC. Effects of dulcitol were examined on collagen-induced arthritis (CIA) in DBA/1J mice. From 6 weeks after the first immunization with bovine type II collagen, dulcitol (100 mg/kg body weight/day) was administered orally to immunized mice for 9 weeks. Clinical score of CIA was improved significantly by dulcitol intervention compared with the non-treated CIA mice. Radiographic score of phalangeal destruction was also improved by dulcitol treatment. These findings suggest that dulcitol may play a role in regulation of some inflammatory responses in the present arthritis model. Significant reduction of percentage of CD4+ and CD8+ T cell subsets in the spleen leucocytes of CIA mice was observed by flow cytometry. Almost normal level of CD4+ and CD8+ T cells was observed in dulcitol-treated groups, suggesting T cell-modifying effect of dulcitol in CIA. Weight of spleen was larger in CIA mice and it was not affected by dulcitol. Anti-collagen antibody titer was increased in CIA mice, and it was not affected by dulcitol, either. Improvement of the changes of CD4+ and CD8+ T cells in the spleen by dulcitol may suggest its modulatory effect on cellular immunity.

Transplantation of microencapsulated PC12 cells provides long-term improvement of dopaminergic functions

The purpose of this study is to examine if microencapsulated PC12 cells may provide long term effects to the hemiparkinsonian rats. A modified technique was used to encapsulate PC12 cells into gelled microspheres. We found that the PC12 cells can survive in the modified microcapsules in vitro. Most of the PC12 cells formed cluster 3 weeks after incubation. The PC12 cell-loaded microcapsules were also examined in vitro. Adult Sprague-Dawley rats, anesthetized with chloral hydrate, were injected unilaterally with 6-hydroxydopamine into the medial forebrain bundle. The effectiveness of this lesion was tested by measuring apomorphine or methamphetamine-induced rotation one month after lesioning. The unilaterally lesioned rats were transplanted with microencapsulated PC12 cells. Results showed that apomorphine and methamphetamine-induced rotations were greatly suppressed after transplantation. One year after the grafting, the animals were anesthetized with urethane for the voltammetric study. Low dose of KCl was directly injected into the grafted striatum through pressure microejection. We found that KCl-induced DA release, as measured by voltammetric techniques, was regenerated in the striatum. The animals were later sacrificed for histological examination. We found that capsules were present in the lesioned striatum one year after grafting. Most of the capsules contained no PC12 cell. However, some capsules were filled entirely with PC12 cells. Taken together, our data suggested that PC12 cells can survive in the capsule in vitro and may provide long-term dopaminergic effects to the hemiparkinsonian rats.

Conditional, tissue-specific expression of Q205L G alpha i2 in vivo mimics insulin action

Deficiency of the G protein subunit G alpha i2 that is known to mediate the inhibitory control of adenylylcyclase impairs insulin action [11]. Using the promoter for the phosphoenolpyruvate carboxykinase gene, conditional tissue-specific expression of the constitutively active mutant form (Q205L) of G alpha i2 was achieved in mice harboring the transgene. Expression of Q205L G alpha i2 was detected in liver and adipose tissue of transgenic mice. Whereas the G alpha i2 deficient mice displayed blunted glucose tolerance, the Q205L G alpha i2 expressing mice displayed enhanced glucose tolerance. Hexose transport and the recruitment of GLUT4, but not GLUT1, transporters to the membrane were elevated in adipocytes from Q205L G alpha i2 expressing mice in the absence of insulin. Additionally, hepatic glycogen synthase was found to be activated in Q205L G alpha i2 expressing mice, in the absence of the administration of insulin. Serum insulin levels in transgenic mice fasted overnight were equivalent to those of their control littermates. These data demonstrate that much as G alpha i2 deficiency leads to insulin resistance, expression of Q205L constitutively active G alpha i2 mimics insulin action in vivo, reflecting a permissive role of G alpha i2 in signaling via this growth factor receptor tyrosine kinase linked pathway.

[Clinical study on combined treatment of shuizhi tuyuan powder and nifedipine in treating hypertension patients complicated with left ventricular hypertrophy]

Patients with essential hypertension complicated with left ventricular hypertrophy (LVH) confirmed by ultrasonic cardiography were divided randomly into observation group and control group. Both groups were treated with nifedipine. Shuizhi Tuyuan Powder (SZTYP, consisted of Hirudo nipponia and Eupolyphaga sinensis) was given in addition to the observation group. The therapeutic course for the two groups were 6 months. Results showed that after one course of treatment, the myocardial weight index lowered from 136.8 +/- 7.5 g/m2 to 130.5 +/- 6.4 g/m2 in observation group, while in control group, it lowered from 136.7 +/- 7.4 g/m2 to 134.3 +/- 6.2 g/m2, the difference between the two groups was significant (P < 0.01). The symptoms were relieved in part of the patients with early stage of cerebrovascular disease treated with SZTYP. The results suggested that SZTYP combined with nifedipine has active curative effect on essential hypertension patients complicated by LVH and part patients in early stage of cerebrovascular disease.

Anatomic fitting studies of a total artificial heart in heart transplant recipients. Critical dimensions and prediction of fit

Anatomic fitting studies of the Cleveland Clinic-Nimbus total artificial heart were performed in 33 patients undergoing heart transplantation. The pump fit in the pericardial space in 20 men (80%) and 4 women (50%). There was no significant difference between the Fit and Non-Fit groups in external chest dimensions. Among 42 intrathoracic dimensions, the distance from the center of the mitral valve to the diaphragm (Fit: 5.6 +/- 2.2 cm, Non-Fit: 3.6 +/- 0.4 cm, p < 0.00001) and the distance from the caudal end of the pulmonary valve to the diaphragm (Fit: 9.4 +/- 1.6 cm, Non-Fit: 6.3 +/- 0.8 cm, p < 0.0001) were the most critical. To predict anatomic fit, an index (A x B x C) was obtained from chest X-ray measurements (A, the craniocaudal distance from the dorsal region of the 8th left rib to the left diaphragm; B, the maximum left chest width; and C, the maximum anteroposterior sternum-vertebrae dimension). The pump fit in 88.5% of the patients with an index above 1200 cm3, whereas it fit in only 14.3% of the patients with an index below 1200 cm3 (p < 0.001). This index was an easily obtainable, good predictor of anatomic fit.

In vitro evaluation of automatic control performance of a total artificial heart with changes in pump orientation

Unlike in animal experiments, the pump orientation of a total artificial heart (TAH) can change remarkably in humans with the recipient's posture (upright, supine, or prone), thus affecting its filling characteristics. The left master alternate control mode of the Cleveland Clinic-Nimbus (CC-N) TAH adjusts beat rate by maintaining the left pump at 90% filling, producing a Frank-Starling like preload sensitivity. In order to verify that the CC-N TAH functions properly regardless of the gravity effects on pump filling, the preload sensitivity curves of the CC-N TAH were evaluated on a mock circulatory loop with the simulated supine (right pump up) and prone (left pump up) positions in humans. The right preload sensitivity was slightly higher when the right pump was up versus down, and likewise the left preload sensitivity was higher when the left pump was up versus down. Despite these gravity effects on pump filling, right and left preload sensitivity remained within physiologic range and the automatic control of the CC-N TAH functioned properly without significant postural effects.

Autocorrelation of integrated power Doppler signals and its application

The integrated power Doppler signal arising from blood flow is a random process. In this article, a general approach to model this random process is studied. Both the theoretical and experimental results show that the temporal autocorrelation function of the integrated power Doppler signals is directly related to properties of the insonified medium, such as the scattering strengths and velocities of all moving scatterers, and as well as the properties of the Doppler imaging system, such as the point spread function (psf) of the power Doppler images. Some initial experiments are performed to test the proposed model. Its potential application for flow measurement, such as perfusion evaluation, is also discussed.

Fractional moving blood volume: estimation with power Doppler US

PURPOSE

To estimate the fraction of moving blood in tissue with power Doppler ultrasound (US).

MATERIALS AND METHODS

Power Doppler US measurements of moving scatterers in a flow tube were made as a function of successive dilutions of the perfusate. Measurements were normalized relative to the maximum Doppler power in the center of the flow tube at the highest concentration and were used to calculate the fractional dilution of the perfusate for each run with each dilution used to represent increasing amounts of non-moving soft tissue in the sample volume. The technique was also applied to two clinical examples.

RESULTS

Successive dilutions of the perfusate in the flow experiment showed a monotonic, linear decrease in the Doppler power as a function of dilution.

CONCLUSION

The power Doppler US technique has the potential to more accurately estimate alterations in blood flow and has the advantage of being a continuous parameter that can be depth normalized.

Developmental and age-related changes in the D2 dopamine receptor mRNA subtypes in rat brain

The influence of ontogeny and aging on the D2 dopamine receptor mRNA in rat brain were examined using in situ hybridization histochemistry and Northern analysis utilizing oligonucleotide probes complementary to the different D2 mRNA subtypes. At birth, there was a high level of D2 dopamine receptor mRNA in corpus striatum relative to that found in the cerebral cortex and other brain areas. The hybridization signal of striatum (using a probe that hybridizes to both the D2A and D2B mRNA) increased during the first two postnatal weeks, reached a peak at day 16, then declined slightly. The D2A mRNA showed a similar distribution and developmental pattern. Intracisternal injection of 6-hydroxydopamine into neonates did not significantly alter the increase of the D2 dopamine receptor mRNAs, suggesting that neuronal input does not influence the ontogenetic development of this mRNA. In striatum, olfactory tubercule and inferior colliculus, the D2A mRNA declined between 3 and 24 months of age. By contrast, there was an age-related increase in the D2A mRNA in the anterior and intermediate lobes of the pituitary. The mRNA for the D2B dopamine receptor showed very low but nevertheless detectable levels in striatum, olfactory tubercule and pituitary. Like with the D2A mRNA, in 24-month-old rats the D2B mRNA declined in striatum and olfactory tubercule and increased in pituitary. These results show that there are differential tissue-related changes in the mRNAs for the D2 dopamine receptor during both development and aging.

Irreversible blockade of D2 dopamine receptors by fluphenazine-N-mustard increases D2 dopamine receptor mRNA and proenkephalin mRNA and decreases D1 dopamine receptor mRNA and mu and delta opioid receptors in rat striatum

The consequences of irreversibly-inhibiting D2 dopaminergic receptors on the expression of D1 and D2 dopamine receptor mRNAs and proenkephalin mRNA and on the levels of mu- and delta-opioid receptors in rat striatum were studied following single or repeated administration of the irreversibly-acting D2 dopamine receptor antagonist, fluphenazine-N-mustard (FNM). The density of dopamine and opioid receptors was determined by receptor autoradiography and the levels of the mRNA for the D1 and D2 dopamine receptors and proenkephalin were measured by in situ hybridization histochemistry. Repeated treatment of rats with FNM for 6 days produced more than 80% inhibition of D2 dopamine receptors but less than 25% inhibition of D1 dopamine receptors. Repeated treatment with FNM also resulted in statistically significant increases in D2 dopamine receptor mRNA but decreases in D1 dopamine receptor mRNA. In contrast, acute treatment with FNM for 3 h had no significant effects on D1 or D2 dopamine receptor mRNAs in striatum. An examination of the effects of FNM on the opioid system showed that repeated treatment with FNM for 6 days produced more than a 2-fold increase in the expression of proenkephalin mRNA in striatum. This was accompanied by significant decreases in mu- and delta-opioid receptors in striatum, mainly by reducing the size of the patch compartment of striatum. Acute treatment with FNM for 3 h produced small increases in proenkephalin mRNA and mu-opioid receptors in striatum but had no significant effects on delta-opioid receptors. These results suggest that persistent inhibition of D2 dopamine receptors differentially regulates the expression of D1 and D2 dopamine receptor mRNA in striatum, and that the magnitude, duration and interval of inhibiting dopaminergic transmission may be important factors in regulating dopamine receptor mRNA expression. These results also suggest that D2 dopamine antagonists indirectly down-regulate opioid receptors by increasing the expression of proenkephalin mRNA, thereby increasing enkephalin which, in turn, decreases opioid receptors in striatum.

Statistical uncertainty in estimates of an effective scatterer number density for ultrasound

In a previous paper [J. Acoust. Soc. Am. 95, 77-85 (1994)], a method for determining an effective scatterer number density in ultrasonography was presented. This is the actual number density multiplied by a frequency-dependent factor that depends on the differential scattering cross sections of all scatterers. This method involves evaluating the ratio of the fourth moment to the square of the second moment of echo signals scattered from the sample. The random processes involved in forming these echo signals give rise to an uncertainty in the estimated effective scatterer number density. This uncertainty is evaluated here using error propagation. The statistical uncertainty depends on the effective number of scatterers contributing to the segmented echo signal; it increases when the effective number of scatterers increases. Tests of the statistical uncertainty estimator were in good agreement with uncertainties computed from experimental data.

The Cleveland Clinic-Nimbus total artificial heart. Design and in vitro function

We describe the design and in vitro testing of the Cleveland Clinic-Nimbus electrohydraulic permanent total artificial heart as it nears completion of development. The total artificial heart uses an electric motor and hydraulic actuator to drive two diaphragm-type blood pumps. The interventricular space contains the pump control electronics and is vented to an air-filled compliance chamber. Pericardial tissue valves and biolized blood-contacting surfaces potentially eliminate the need for anticoagulation. In vitro studies on a mock circulatory circuit demonstrated preload-sensitive control of pump output over the operating range of the blood pump: 70 to 160 beats/min and 5 to 9.6 L/min at right and left atrial pressures of 1.0 to 7.0 mm Hg and 5.0 to 12.0 mm Hg, respectively. The pump output was found to be insensitive to afterload over a range of 15 to 40 mm Hg mean pulmonary artery pressure and 60 to 130 mm Hg mean systemic pressure. The left master alternate control mode balanced the ventricular outputs during simulated bronchial artery shunting of up to 20% of cardiac output. A 10% to 15% right-pump, stroke-volume limiter balanced ventricular outputs during maximum output of 9.6 L/min. In response to a sustained increase in systemic venous return, the pump increased output by 2 L/min (29%) in 35 seconds. Thus the Cleveland Clinic-Nimbus total artificial heart meets the National Heart, Lung, and Blood Institute hemodynamic performance goals for devices being developed for permanent heart replacement. The biolized blood-contacting surfaces should decrease the risk of thromboembolism associated with circulatory assist devices.

Progress in Cleveland Clinic-Nimbus total artificial heart development

A totally implantable, Cleveland Clinic-Nimbus total artificial heart (TAH) uses electrohydraulic energy conversion and an automatic left master-alternate mode control scheme, with a filling sensitivity of 1.0 l/min/mmHg and a maximum output of 9.5 l/min. The TAHs were tested in 12 calves for 1-120 days with normal major organ and blood cell function. Post-operative suppression of platelet aggregation recovered by the second post-operative week. The gelatin-coated pump surface generally was clean without any anticoagulants and free from infection. Embolism, which occurred in two cases, was caused by complications attributable to fungal infection in a Dacron graft and by thrombus formed around a jugular vein catheter. A system with a hybridized microcircuit controller in the interventricular space has been tested successfully in the three most recent cases, with a peak device surface temperature elevation of 6.5 degrees C. Heat effects were confined to the tissues immediately adjacent to the hottest spots. The carbon fiber-reinforced epoxy housing and 60 ml butyl rubber compliance chamber showed good tissue compatibility with a thin, fibrous tissue capsule. The transcutaneous energy transmission system and the internal battery functioned well as designed in the most recent animal implant.

Adaptation of tissue to a chronic heat load

Determination of the chronic effect of heat on tissue is one of the important issues facing mechanically actuated total artificial heart (TAH) development. In an effort to characterize this effect, implantations of heating devices producing constant heat fluxes of 0.04 watts/cm2, 0.06 W/cm2, and 0.08 W/cm2 were performed in 11 calves (H-series). Heated disks were implanted adjacent to lung and muscle tissue for a period of 7 weeks. Temperature sensors were placed at the surface as part of the heater assemblies. The results showed that initially, temperature elevations above body temperature (delta T) were 6.4 +/- 0.6 degrees C, 4.5 +/- 0.2 degrees C, and 1.8 +/- 0.5 degrees C at the muscle heater surface for 0.08, 0.06, and 0.04 W/cm2, respectively. At 2 weeks after implant delta T values changed to 5.5 +/- 0.6 degrees C, 3.4 +/- 0.2 degrees C, and 1.8 +/- 0.2 degrees C, respectively. Seven weeks after implant, delta T values decreased to 3.7 +/- 1.2 degrees C, 2.8 +/- 0.1 degrees C, and 0.8 degrees C for 0.08, 0.06, and 0.04 W/cm2, respectively. The authors think this change is attributable to an adaptive response of the tissue to increase heat dissipation through angiogenesis. Results from three TAH cases indicated that at two measured tissue interfaces, delta T decreased by 1 degrees C during a 15 day period. At the same time, the waste heat (volts x current in-flow x afterload to the blood) remained constant at 11.1 +/- 0.5 W during this period. This decrease in delta T corresponded to that observed for the H-series experiments at the higher heat fluxes. Thus, it appears that adaptation observed in the H-series experiments also is seen for tissues surrounding heat sources such as the TAH.

Lesions of mouse striatum induced by 6-hydroxydopamine differentially alter the density, rate of synthesis, and level of gene expression of D1 and D2 dopamine receptors

To study the effects of altering dopaminergic input on the levels and rate of synthesis of dopamine receptors, corpora striata of mice were lesioned unilaterally with 6-hydroxydopamine (6-OHDA), and the densities and levels of the mRNAs for D1 and D2 dopamine receptors were determined. The results showed that 6-OHDA caused significant reductions in D1 dopamine receptors and in D1 dopamine receptor mRNA in dorsolateral and dorsomedial regions of the lesioned striatum. By contrast, 6-OHDA lesions caused significant increases in D2 dopamine receptors and in D2 dopamine receptor mRNA in dorsolateral and ventrolateral regions of the lesioned striatum. To assess the effects of 6-OHDA lesions on the rate of synthesis of D1 and D2 dopamine receptors, the irreversibly acting dopamine receptor antagonist 2-ethoxy-1-ethoxycarbonyl-1,2- dihydroquinoline (EEDQ) was administered, and the rate of recovery of these receptors determined. The lesions decreased the rate of synthesis of D1 dopamine receptors in dorsolateral striatum but increased the rate of synthesis of D2 dopamine receptors in dorsolateral striatum. Correlation of these molecular events with dopaminergic behaviors showed that the rate of recovery from EEDQ-induced cataleptic activity and the recovery from inhibition of quinpirole-induced rotational behavior was more rapid than the recovery of either the D1 or D2 dopamine receptor. These results suggest that dopaminergic denervation differentially affects the rate of synthesis of D1 and D2 dopamine receptors in mouse striatum, and that these alterations in the rates of synthesis of the receptors may be explained by corresponding alterations in the levels of the respective transcripts for these receptors.

A method for determination of frequency-dependent effective scatterer number density

Previous researchers have shown that for low scatterer concentrations, the scatterer number density in an ultrasound pulse-echo experiment can be obtained from ratios of the fourth to the second moment of the backscattered signal. In this paper a new method is presented for determining an effective scatterer number density, which is the actual number density multiplied by a frequency-dependent factor that depends on the differential scattering cross sections of all scatterers. The method of data reduction goes beyond the work of previous authors in that, in addition to accounting for the possibility that different sets of scatterers may dominate the echo signal at different frequencies, it also explicitly retains both the temporal nature of the data acquisition and the properties of the ultrasound field in the data reduction. Tests of the method in phantoms yielded good agreement between measured values of the effective scatterer number density and number densities calculated using first principles.

Compliance effects on small diameter polyurethane graft patency

Microporous compliance matched and noncompliant grafts were compared in a dog carotid artery interposition model. We fabricated 4 mm diameter sponge type polyurethane (Biomer) tubes 5 cm in length with a 0.5 mm wall thickness. The luminal surface was covered with a 50 microns coating of cross-linked gelatin. Compliance was measured in vitro and in vivo by volume and vessel diameter changes. Over a mean arterial pressure range of 55-155 mm Hg, the diameter changes of grafts and stump arteries were measured in situ using an ultrasonic Hokanson device. Compliance matched grafts were found to have the same in vitro compliance values as the natural canine carotid at a mean arterial pressure of 100 mm Hg. Compliance matched and noncompliant grafts had values of 10.3 +/- 1.3 and 0.9 +/- 0.1 x 10(-2) mm Hg, respectively. End to end arterial anastomoses were constructed between the graft and the host arteries. The use of synthetic grafts with matched compliance to the adjacent natural vessels has been advocated as the ideal solution to circumvent the problems of graft failure. These studies indicate that compliance values for compliance matched grafts decreased immediately after implantation (from 10.3 to 6.5 x 10(-2) %/mm Hg) and within 6 weeks decreased to 3.6 x 10(-2) %/mm Hg. The compliance values for noncompliant grafts remained constant throughout the test period. At autopsy all grafts showed a tightly adhered tissue capsule. The thickness of the anastomotic hyperplasia at the distal sites of compliance matched grafts was significantly different (P < .05) than that of the adjacent artery. The patency for compliant and noncompliant grafts was 64% and 50%, respectively. Evidence for polyurethane graft degradation was obtained by Fourier transform infrared spectroscopy and gel permeation chromatography analysis of patent explants. Compliance mismatch alone does not contribute to graft failure, however, material degradation, suture technique and/or capsule formation can play a contributory role although these were not tested directly.

Continuing development of the Cleveland Clinic-Nimbus total artificial heart

A completely implanted total artificial heart (TAH) is under development by Nimbus, Inc., and the Cleveland Clinic Foundation (CCF). Key features of the system include an electrohydraulic energy converter, an automatic control system that produces a Frank-Starling response, and dual ventricles composed of graphite-epoxy and titanium with gelatin blood contacting surfaces. The system is controlled by a single substrate, hybridized microcircuit (the hybrid). Fabrication of the TAH control hybrid has recently been completed and testing begun. Its design emphasizes simplicity, reliability, and efficiency. Particular attention was given to optimizing thermal management. Externally controlled TAH systems have been used in eight in vivo experiments of up to 120 days' duration. In the last two of these experiments, a variable volume device was also implanted with excellent results. In vivo use of the system has demonstrated the Frank-Starling pump response, but the systems quickly reach maximum output with the bovine animal models. Human fitting studies, including adult patients undergoing heart transplantation, demonstrated satisfactory fit of the pump within the pericardium without compression of the vascular structures or chest wall. Measurements of chest circumference, plain chest films, and transesophageal echocardiograms should provide reliable predictions of pump fit in the majority of patients.

Hemodynamic Changes with Posture in Calves with Total Artificial Heart

Hemodynamic changes with posture, sitting versus standing, were analyzed in five Holstein calves with the Cleveland Clinic-Nimbus TAH. This total artificial heart (TAH) has a left master alternate control mode that adjusts the pump rate and consequently pump flow proportional to the pulmonary venous return to the left pump (AUTO period). However, in this series of experiments, the pump reached its maximum beat rate within 1-5 days post operatively, after which pump flow could not increase (MAX period). Hemodynamic parameters (RAP, LAP, PAP, AoP, and pump flow) were obtained every 15-20 min throughout the experiments for as long as 120 days and averaged for each posture for each period. During the AUTO period, the flow while standing was significantly higher than that while sitting (standing: 8.7 +/- 0.2 L/min; sitting: 7.5 +/- 0.4 L/min; p < 0.05), and the systemic vascular resistance (SVR) was significantly lower (standing: 895 +/- 93 dyne.sec.m-5; sitting: 1,041 +/- 124 dyne.sec.m-5; p < 0.05). During the MAX period, the AoP and SVR standing were significantly lower than those sitting (AoP standing: 91 +/- 7 mmHg; AoP sitting: 98 +/- 7 mmHg; p < 0.05; SVR standing: 652 +/- 75 mmHg; SVR sitting: 730 +/- 96 mmHg; p < 0.05). The Cleveland Clinic-Nimbus TAH responded well to these changes in position, increasing pump flow and maintaining the AoP during the AUTO period.

Effects of a total artificial heart right stroke volume limiter on left-right hemodynamic balance

In a completely implantable total artificial heart (TAH), the left-right flow difference attributable to higher volumetric efficiency of the right pump and bronchial artery shunting has always been a significant problem. The automatic control of the Cleveland Clinic-Nimbus TAH accommodates for the left-right flow difference when the beat rate is below maximum (AUTO range). However, at its maximum beat rate (MAX), high left atrial pressure (LAP) (greater than 25 mmHg) with relatively low right atrial pressure (RAP) (less than 8 mmHg) were observed both in vitro and in vivo, suggesting the need for a stroke volume limiter (SVL) of the right pump. In vitro volume loading tests showed 10%, 15%, and 20% SVLs prevented a disproportionate increase of LAP. In vivo studies in five Holstein calves also showed a balanced LAP-RAP relationship with 10% and 15% SVLs at MAX. The left pump flow was not affected by this range of SVLs either in vitro or in vivo. Pulmonary function was maintained with either size SVL, with autopsies revealing absence of pulmonary congestion and minimal pleural effusions in two calves surviving for more than 1 month. Although additional studies are needed to determine the appropriate size of the SVL, both 10% and 15% SVLs were effective in maintaining left-right hemodynamic balance in this TAH.

[Primary hyperparathyroidism with parathyroid adenocarcinoma in a patient with Turner's syndrome complicated with thyrotoxicosis]

We report a rare case of Turner's syndrome coexisting with thyrotoxicosis and parathyroid adenocarcinoma resulting in hyperparathyroidism. This 45-year-old female patient presented with primary amenorrhea and poor development of secondary sexual characteristics. She also experienced repeated bone fractures, and body weight loss. Multiple risk factors of osteoporosis developed simultaneously in this patient. The interesting interactive relationship of hypercalcemia between thyrotoxicosis and primary hyperparathyroidism was noted. The best choice was surgery for both cases. Calcium supplements and various hormone replacements in addition to regular investigative radionuclide scans were required.

Continuous treatment with the D2 dopamine receptor agonist quinpirole decreases D2 dopamine receptors, D2 dopamine receptor messenger RNA and proenkephalin messenger RNA, and increases mu opioid receptors in mouse striatum

Dopamine-mediated behaviors and certain biochemical and molecular events associated with these behaviors were examined following continuous infusion of the D1 dopamine agonist SKF38393 or the D2 dopamine agonist quinpirole into mice for six days. SKF38393 produced a transient grooming behavior while quinpirole initially induced stereotypy, which was followed by an increased locomotor behavior. Continuous infusion of quinpirole caused a significant down-regulation of striatal D2 dopamine receptors without significantly changing the density of D1 receptors. This was accompanied by a decrease in the level of D2 receptor messenger RNA in striatum as measured by Northern analysis. The down-regulation of dopamine receptors was selective for D2 dopamine receptors, since treatment with SKF38393 had no significant effects on either D1 or D2 dopamine receptors, nor did it alter the messenger RNAs for the D1 and D2 receptors. Continuous treatment with quinpirole resulted in a significant increase in striatal mu opioid receptor levels without significant changing delta opioid receptors. This treatment also induced a significant decrease in proenkephalin messenger RNA in striatum. Taken together, these results suggest that the down-regulation of D2 dopamine receptor and D2 receptor messenger RNA is the result of the persistent stimulation of D2 receptors and that the up-regulation of mu opioid receptors may be a compensatory response to a decreased biosynthesis of enkephalin. They suggest further that the biochemical and molecular changes that take place in dopaminergic and enkephalinergic systems following continuous treatment with dopamine agonists may underlie the mechanisms by which certain dopamine-mediated behaviors occur.

Irreversible blockade of D2 dopamine receptors by fluphenazine-N-mustard increases glutamic acid decarboxylase mRNA in rat striatum

The influence of dopaminergic activity on the function of GABAergic neurons in striatum was examined by administering rats the irreversible D2 dopamine receptor antagonist, fluphenazine-N-mustard (FNM), and determining the level of glutamic acid decarboxylase (GAD) mRNA in striatum. Rats were given either an acute single injection or chronic daily injections of FNM (20 mumol/kg, i.p.) for 6 days. The level of GAD mRNA in striatum was determined by in situ hybridization histochemistry. The results showed that acute treatment with FNM failed to significantly change striatal GAD mRNA. However, chronic FNM treatment significantly increased in the level of striatal GAD mRNA. These results demonstrate that irreversible blockade of D2 dopamine receptors increases the expression of GAD mRNA in rat striatum.

Tests of backscatter coefficient measurement using broadband pulses

An adaptation to a data reduction method is outlined for determining backscatter coefficients, eta, when broad-bandwidth pulses are employed. The accuracy of these eta values is assessed with well-characterized phantoms, for which backscatter coefficients based on their physical properties have been independently calculated. One phantom produces Rayleigh-like scattering, where the backscatter coefficient varies smoothly with frequency over the analysis bandwidth. A second phantom exhibits local maxima and minima in the scattering function versus frequency due to the presence of millimeter-sized graphite gel spheres in a gel background. The method was found to produce accurate results using time gate durations as small as 2 mus, although better accuracy is obtained for longer gate durations, particularly when the sample exhibits resonance peaks in backscatter versus frequency. Use of a Hamming window in place of a rectangular window extends the accuracy near the upper and lower limits of the frequency range.

Ultracytochemical studies on Trichomonas hominis

The results of ultracytochemical studies on Trichomonas hominis showed that ACPase and CMPase were mainly located in the mature face sacs of the primary lysosomes, digestive vacuoles, as well as in the parabasal body. TPPase and NADPase were found in the saccules at the mature face and the intermediate saccules of parabasal body respectively. This study revealed that T. hominis had well-developed parabasal bodies. Negative COase and catalase reactions indicated that T. hominis lacked both mitochondria and microbody. Hydrogenosome was stained well with the Ur-Pb-Cu impregnation technique.

Biodegradable pericardial implants for bladder augmentation: a 2.5-year study in dogs

Bladder augmentation using biodegradable pericardial tissue was evaluated in canine bladders. Acetic acid and acetic anhydride treated pericardial tissue grafts were stored in 75% ethanol for 18 to 27 months before implant. Ten dogs weighing 20 to 25 kg. were subjected to a 50% partial cystectomy. After careful separation of the mucosa, bladder muscle and adventitial layers a pericardial graft volumetrically equivalent to the portion of the bladder removed was sutured to the bladder remnant in 2 layers. In 1 control dog the bladder was opened, 50% of the bladder was removed and the bladder was closed primarily. In another control dog the excised bladder was replaced with fresh chemically treated patch material that was never subjected to ethanol storage. Excretory urography and cystography were performed on all dogs. Urodynamics with filling pressures and bladder volumes measured before and after the operation at intervals of up to 36 months confirmed that adequate bladder capacity was achieved. There were no operative complications. Postmortem histological evaluations revealed a smooth epithelialized inner surface with no traces of any surface irregularities or suture lines. The bladder apex showed an intact epithelium and the absence of a smooth muscle layer. The biodegradable acetylated tissue provides an intact structural reservoir for urine and serves as a template for epithelial regeneration. This permits volumetric bladder enlargement while the graft is progressively reabsorbed with time.

Initial in vivo tests of an electrohydraulic actuated total artificial heart

The authors are involved in developing a total artificial heart (TAH) for permanent human use. This device was designed to fit human anatomy, and it has housings made of carbon fiber-epoxy composite and titanium. Tissue valves and protein coating of blood contacting surfaces minimize the need for anticoagulants. A continuously reciprocating electrohydraulic actuator is packaged between two alternately ejecting and passively filling ventricles. The control system varies the pump rate to maintain average left ventricular filling at 90%. This TAH in vivo successively progressed through 1, 5, 9, and 45 day implants in calves of 84, 94, 82, and 82 kg preoperative body weights. The operating modes include automatic and fixed rate. The chronic and acute effects of varying the right pump displaced stroke volume indicated the need for it to be limited to 85% of that of the left for stable hemodynamics at maximum flow. The pump exhibited afterload insensitive and preload sensitive performance. Pump output ranged from 4.0-9.5 L/min at left atrial pressures of 7-16 mmHg at pump rates of 80-160 beats/min in these four experiments. These data suggest that this device will meet clinical hemodynamic requirements; it has the potential for total implantable cardiac replacement.

Effects of mechanical ventilation and spontaneous respiration on hemodynamics in calves with total artificial hearts

The effects of respiration on hemodynamics were evaluated in four Holstein calves with total artificial hearts (TAH). The electrohydraulic actuated E4T-TAH has a continuously reciprocating actuator packaged between two alternately ejecting blood pumps that passively fill. The hemodynamic parameters (right atrial pressure [RAP], left atrial pressure [LAP], pulmonary artery pressure [PAP], aortic pressure [AoP]), and right and left pump filling (Rt% fill and Lt% fill) were measured when the animal was intubated and mechanically ventilated. These measurements were repeated with spontaneous respiration after the animal was extubated. With mechanical ventilation, LAP, PAP, and AoP were significantly higher during inspiration than during expiration. However, RAP during inspiration was slightly lower than that during expiration. The Rt% fill during inspiration was significantly lower than during expiration, but Lt% fill during inspiration was significantly higher than during expiration. During spontaneous respiration, these changes were opposite to those observed during mechanical ventilation. That mechanical ventilation generates positive intrathoracic pressure during inspiration, but spontaneous respiration generates negative pressure may explain these results. The change in venous return to the right atrium caused the change in RAP to be opposite in direction to that of the other pressures.

Ontogenetic expression of D2 dopamine receptor mRNA in rat corpus striatum

The ontogenetic expression of the D2 dopamine receptor (D2R) mRNA has been characterized in rat corpus striatum by in situ hybridization histochemistry and Northern and slot blot analyses using oligonucleotide probes directed toward either the D2R-A subtype of the D2R mRNA or to both the D2R-A and D2R-B subtypes of the D2R mRNA. The results showed that both D2R mRNAs were detected in rat striatum at birth, gradually increased until day 16 postnatally (P16), then declined slightly. At early stages of development, the hybridization signal, when viewed under low magnification, was fairly evenly distributed throughout the striatum. However, later in development (P16) a cluster pattern became manifest. Autoradiographic studies using the mu-opiate receptor as an indication of striatal 'patches' in serial, adjacent sections of striatum indicated that the cluster pattern of the D2R mRNA was not associated solely with the patch or matrix compartments of the striatum. A cellular analysis showed that at early developmental stages the quantity of D2R mRNA per cell was very low in striatum. During the first two postnatal weeks, certain subpopulations of striatal neurons evidenced a marked increase in the expression of D2R mRNA per cell. Administration of 6-hydroxydopamine into neonatal rats failed to significantly change the developmental profile of D2R mRNA in the rat striatum of 16- and 32-day-old animals, although the same treatment caused a marked increase in proenkephalin mRNA. These results suggest that the postnatal development of the D2R mRNA in rat striatum correlates well with the ontogeny of the D2 dopamine receptor, that the developmental expression of the D2R mRNA is highly associated with the maturation and differentiation of striatal neurons, and that the development of the D2R mRNA in rat striatum, unlike that of proenkephalin mRNA, can proceed even with reduced dopaminergic afferent input from the substantia nigra.

Neuronal localization and modulation of the D2 dopamine receptor mRNA in brain of normal mice and mice lesioned with 6-hydroxydopamine

A novel oligonucleotide probe was designed, characterized and utilized to study the distribution and modulation of the mRNA encoding the D2 dopamine receptor in the brain of the mouse. Using in situ hybridization histochemistry, the highest levels of the D2 receptor mRNA were found in regions of the brain containing the cell bodies and the terminal projection fields of the nigrostriatal, mesolimbic and mesocortical dopaminergic systems. Particularly high levels of the D2 receptor mRNA were found in substantia nigra pars compacta, ventral tegmental area, caudate-putamen and olfactory tubercle. This distribution generally paralleled that of the D2 dopamine receptor. Some areas, not usually associated with dopaminergic systems, also contained significant levels of the D2 receptor mRNA signal. These areas included the hippocampus, certain thalamic nuclei, the inferior colliculus and the spinal trigeminal nucleus of the medulla and spinal cord. Lesioning the corpus striatum with 6-hydroxydopamine had little effect on the level of the D2 receptor mRNA in the striatum but greatly reduced the hybridization signal in the substantia nigra pars compacta and ventral tegmental area. Similarly, lesioning the substantia nigra, nearly abolished the signal in the pars compacta but failed to substantially alter the D2 receptor mRNA signal in the striatum. These results suggest that the D2 receptor mRNA in the substantia nigra pars compacta was localized largely to dopaminergic cell bodies, the terminal projections of which lie in the striatum and codes for D2 autoreceptors and that the D2 receptor mRNA of the striatum is in non-dopaminergic cell bodies that are intrinsic to the striatum and probably codes for post-synaptic D2 receptors. Further, the evidence that lesions of striatum and substantia nigra induced with 6-hydroxydopamine greatly reduced the D2 receptor mRNA signal in the substantia nigra, without concomitantly increasing the D2 receptor mRNA in the striatum, suggests that the increase in dopamine receptor binding in the striatum that is ipsilateral to the lesion with 6-hydroxydopamine and the enhanced behavioral sensitivity to dopaminergic agonists, cannot be accounted for solely by an increase in D2 receptor mRNA.

Optimization of pacing parameters for conditioned latissimus dorsi muscle in cardiomyoplasty

Synchronous paced contractions of latissimus dorsi muscle pedicle (LDM) around the heart improve ventricular function in dynamic cardiomyoplasty. To optimize assistance and prolong pacemaker battery life, the LDM should be stimulated with the lowest energy pacing parameters (PP) that will produce maximal muscle contraction. Muscle fractional shortening (FS) and duration of contraction (CT) were studied in conditioned, fatigue-resistant LDM of six goats. Fractional shortening and CT were determined at increasing amplitude, (A, 1-6v); pulse width, (PW, 60-450 musec); and frequency, (F, 5-130 Hz). Maximal rate of contraction was determined by pacing at higher rates. Maximal FS plateaued after V, 2.4 +/- .6v; PW, 125 +/- 47 musec; and F, 36 +/- 9 Hz. Mean CT for all PP was significantly longer (p less than or equal to 0.001) than the burst length (185 msec). Increasing F resulted in CT, which peaked at 460 +/- 59 msec. Increasing rate of contraction demonstrated that over 87 beats per minute the muscle fails to achieve complete relaxation, and, therefore, maximal FS.

Characterization of rehydrated gelatin gels

Five percent glutaraldehyde cross-linked gels have shown excellent blood compatibility as coatings for cardiac prostheses. A method was developed for producing thin dehydrated coatings using a proprietary dehydration procedure and ethylene oxide (EO) sterilization. The swollen surfaces of rehydrates versus wet (original) gels were compared. Within 30 min of saline rehydration, dry 30-50-microns films on textured surfaces became smooth, uniform, and comparable to original gelatin gels. Mechanical test results after rehydration showed values for strain remain unchanged (39.3 + 10.0 to 40.0 + 7.8%), but stress increased (2.79 + 1.21 to 4.22 + 1.60 dyne/cm2; p less than 0.01). The contact angle data reported gamma C values of 26.1 and 30.4 dyne/cm for original and rehydrated gels. Using a coulometric titrimeter, the measured water content of original gels was reduced from 85 to 3.4% after drying. Dried and saline rehydrated gels had a 73.2% moisture content. Gels shrank 8.8% of their original length after rehydration; however, the thickness of all pump coatings remained stable. Two-hour incubations with bovine platelet rich plasma showed no differences in platelet reactivity or morphology when compared to original gels. Light microscopy and scanning electron microscopy (SEM) showed no evidence of gel cracking or surface defects after pump endurance testing for 3 and 5 weeks. The process of dehydration eliminates the wet storage and sterility problems of such hydrogels and provides a stable film coating for a variety of blood-contacting substrates.

Ontogenetic development of calmodulin mRNA in rat brain using in situ hybridization histochemistry

An oligonucleotide probe complementary to the area on calmodulin coding for the calcium binding domain II on calmodulin was used to study the ontogenetic development of calmodulin mRNA in rat brain using in situ hybridization histochemistry. The hybridization signal for this probe was saturable, RNAse sensitive and was displaced by excess unlabelled calmodulin probe but was not displaced by an S-100 probe or by another calmodulin probe which was complementary to the mRNA coding for a different portion of calmodulin. At birth, high levels of calmodulin mRNA were found in hippocampus, cerebral cortex, thalamic nuclei and corpus striatum, and relatively low levels were in white matter. The rate at which calmodulin mRNA changed during development in the different brain areas varied with the brain area. At postnatal day one, the highest hybridization signals were in the cortical plate of the cerebral cortex, in thalamus and in the pyramidal cell layers of hippocampus and pyriform cortex. This distribution became more uniform with age. In contrast to most other brain areas, calmodulin mRNA in cerebellum increased markedly between one and 32 days postnatal; the hybridization signal was low at day one and was confined to the external germinal layer, but by day 16 calmodulin mRNA was largely in the granular layer. These results taken together with other findings on the effects of calmodulin on cellular growth differentiation, suggest that calmodulin may play a role in neuronal maturation.

Image processing by microcomputer on ultrastructure of griseofulvin-resistant fungi in favus

The ultrastructure of 5 griseofulvin-resistant fungi of favus was studied by image processing with microcomputer. It was found that the cell walls of the fungi consisted of 8 layers, and the inner layer containing cytoplasm was loose. It was also found that all structures within the cytoplasm possessed a 1-3 layers integral envelope with chromatins in the nucleus. These might be contributing factors in the development of resistance to griseofulvin. This multiple-layered, thick cell wall might act as a barrier responsible for the impermeability of the cell to griseofulvin.

A simple and compact total artificial heart for temporary use

Thromboembolism and anatomic fit are the major issues to be addressed in the design of a heart replacement device for total circulatory support. In an attempt to overcome these problems, a simple 70 mm3 displacement pusher plate, low pressure, pneumatically driven TAH was developed for temporary use. For optimal anatomic fit, easy implantation, and better flow patterns, the 5.7 X 10.7 cm total artificial heart (1) TAH was made of two essentially flat pumps integrated into a single unit. This single package approach avoids the dead space that occurs between the two pieces of conventional TAH and thus minimizes overall volume. It was designed to be positioned in the pericardial sac in a fashion similar to the natural ventricles and, based upon previous anatomic studies, fit in the average sized adult patient. In contrast to conventional free diaphragm pumps, the diaphragms of this TAH are supported by pusher plates that have a unique guide mechanism at the center to ensure a linear-controlled diaphragm motion and consequent uniform blood flow distribution. The guide of each pusher plate nests into the other, resulting in minimal thickness of the package. By using a simple displacement transducer, reliable output monitoring, with the possibility of selection of various pumping modes and adjustment of stroke volume, is possible. The authors anticipate this efficient and practical TAH to be a suitable temporary heart replacement device.

A biolized implantable ventricular assist device compatible with IABP console

A low pressure pneumatic pusher plate blood pump was developed for temporary right, left, or biventricular assist. Important features of this pump are its 1) driveability by the standard, easily available intraaortic balloon pump (IABP) console; 2) gelatin coated internal surface for blood compatibility; 3) essentially flat disc shape, 3 cm thick and 11 cm in diameter, for optimal anatomic fit; and 4) unique pusher plate guide mechanism to ensure linear motion without deflections of the diaphragm, and consequent uniform flow distribution into the pump. The guide telescopes into itself to avoid a housing protrusion for easy implantability; this controlled movement also provides a number of performance, control, and diagnostic benefits. The pump's 60 ml displacement gives up to 4.7 L/min at 80 bpm and 6.7 L/min at 120 bpm outputs in a mock loop. This VAD has been implanted in two calves for 43 to 84 days, continuously driven by a Datascope IABP console. An average 5 L/min pump output has been observed in both synchronous and fixed rate modes. No anticoagulation was required. We expect extensive clinical use of this VAD, based on its reliability, low cost, and simplicity.