In vivo electroporation: a powerful and convenient means of nonviral gene transfer to tissues of living animals (Review)

Although in vivo electroporation is currently an unfamiliar nonviral means of gene transfer, accounting for only about 1% of total studies related to in vivo gene transfer and gene therapy, it may be extensively used for experimental and therapeutic purposes in the near future. Like other nonviral methods, in vivo electroporation has a variety of advantages over viral vectors as: any types of cells and tissues in theory could become a target, handling is easy and quickly done within a matter of second, repeated administration of DNA is possible, no immunogenicity is expected, and there is no constraints on amounts and sizes of DNA to be used. Gene transfer efficiency of in vivo electroporation was found to be equivalent to or even superior to that of in vivo lipofection, gene gun and direct DNA injection methods. Although gene expression exerted is transient and foreign genes are likely to be present in an episomal form when transferred by in vivo electroporation, foreign gene products could be detected for more than 1 month depending on tissues and DNA constructs used. Gene expression generated by in vivo electroporation could be controlled to a certain extent in a tissue- or cell-specific manner, and be induced as intended. Perhaps better appraisal of in vivo electroporation as a nonviral gene transfer method should be brought forth in the future after more detailed analyses.

Evaluation of particulate Bioglass in a rabbit radius ostectomy model

Osseous defects and fractures may require supplimentation to support and promote healing. Bioglass (BG) may be a useful therapeutic for these conditions. Therefore, we executed a study to determine whether particulate BG could promote healing of 20-mm unilateral ostectomies in the radius of rabbits. Ostectomies were either treated with BG or remained untreated in the control (CTL) group. At 4 and 8 weeks post-treatment, ostectomies were assessed histomorphometrically and biomechanically. New bone formation was more intense contiguous to the host bone for both BG and CTL than centrally, yet BG animals displayed active mineralization throughout the ostectomy. The amount of bone within BG-filled defects was greater than CTLs at 4 weeks, whereas, at 8 weeks there was no difference. Biomechanically, the BG-treated limbs required more torque to break than did CTL limbs at 4 weeks; however differences were not significantly different. By 8 weeks, the BG-treated and CTLs, had comparable strength. Bioglass may be a useful therapy to produce the early phase of osseous repair. However, improvements in handling properties of the particles will be needed to enhance efficacy.

Detection of thyroid remnant/metastasis without stunning: an ongoing dilemma

The use of 131I doses of several mCi for scans can stun the thyrocytes and thyroid cancer cells, whereas the usual dose (300 microCi) of 123I does not. We compared the diagnostic accuracy of the 123I (300 microCi) scans and that of 131I (3-10 mCi) scans in 155 patients. The diagnostic accuracy of a 123I scan in detecting functioning thyroid remnant/metastasis was 89.5% (77/86 scans) and that of a 131I scan was 92.9% (39/42) in 6 week-postoperative patients (p = 0.750). For radioablation therapy follow-up patients, the diagnostic accuracy of 123I in determining presence or absence of functioning remnant or metastasis was 69.4% (25/36) and that of 131I was 92.5% (49/53) with a p value of 0.079. The success rates for complete ablation of functioning tissue after radioiodine therapy administered after diagnostic 123I and after 131I were 72% (34/47) and 56% (24/43), respectively, with a p value of 0.125. Our study indicates the following: 1) for the first postoperative evaluation, the diagnostic accuracy of the 123I scan was essentially equal to that of the 131I scan, and the success rate of radioablation therapy appears to be better than 123I scan; and 2) for postablation follow-up surveys, the 131I scan appears to be better but carries the risk of stunning the functioning cells.

Estrogen receptor is not primarily responsible for altered responsiveness of ovalbumin mRNA induction in the oviduct from genetically selected high- and low-albumen chicken lines

The role of estrogen receptor on ovalbumin mRNA induction by steroid hormones was investigated in primary cultures of oviduct cells from estrogen-stimulated immature chicks of genetically selected high- and low-albumen egg laying lines (H- and L-lines). In experiment 1, the extent of ovalbumin mRNA induction and changes in estrogen and progesterone receptors were compared between the oviduct cells from H- and L-lines with or without steroid hormones in the culture medium. In experiment 2, the effect of estrogen receptor gene transfection on the induction of ovalbumin mRNA was studied in the oviduct cells from the L-line chicks. The results showed a close correlation of the changes in ovalbumin mRNA with the numbers of nuclear and total estrogen receptors in the oviduct cells but not with the numbers of nuclear and total progesterone receptors. Estrogen receptor gene transfection induced ovalbumin mRNA to a moderate extent in the absence of the steroid hormones. To our surprise, however, estrogen receptor gene transfection apparently suppressed the ovalbumin mRNA responsiveness to estrogen to a considerable extent. It was concluded, therefore, that the extent of estrogen receptor expression might not be primarily responsible for the differences in responsiveness to steroid hormones of oviduct cells from genetically selected H- and L-line chickens.

Comparative study of interictal PET and ictal SPECT in complex partial seizures

OBJECTIVE

To compare the sensitivity of ictal 99mTc-HMPAO single photon emission computed tomography (SPECT) with interictal 18F-fluoro-deoxyglucose positron emission tomography (PET) in localization of the epileptogenic focus in patients with medically intractable complex partial seizures (MI-CPS).

MATERIAL AND METHODS

Retrospective analysis was performed on patients with MI-CPS who underwent anterior temporal lobectomy from January 1993 onwards when PET became available to us for clinical studies at the Indiana University Medical Center. There were 38 female and 29 male patients (total = 67) with MI-CPS, 10 to 55.5 years of age (mean 31) and duration of their epilepsy from 1-46 years (mean 21). Interictal PET was evaluated for evidence of focal hypometabolism and ictal SPECT for focal perfusion abnormality (hyperperfusion or hypoperfusion) by visual analysis.

RESULTS

Both ictal SPECT and interictal FDG-PET studies were obtained in 36 patients with MI-CPS. PET showed definite hypometabolism in 30 and questionable hypometabolism in an additional two patients. Ictal SPECT correctly localized the seizure focus in 27 patients by demonstrating ictal hyperperfusion whereas in one the hyperperfusion was falsely localized. In an additional seven patients the ictal SPECT provided probable localization by demonstrating ictal hypoperfusion in the appropriate temporal lobe. The sensitivity of ictal SPECT and interictal PET was 34/36 and 32/36, respectively, the difference was not statistically significant (chi 2y = 0.18, DF = 1, P = 0.67). In six of the 36 patients the two tests were complementary to each other in providing localizing information.

CONCLUSION

Ictal SPECT and interictal PET are equally sensitive and reliable techniques in localizing the epileptogenic focus in patients with MI-CPS. They play a critical role in providing localization in MRI negative patients allowing surgical resection to be undertaken in many without additional invasive electrographic monitoring.

Cloning and characterization of chitin synthase gene fragments from Penicillium chrysogenum

DNA fragments homologous to chitin synthase were amplified from the genomic DNA of Penicillium chrysogenum by PCR. Cloning and sequencing of the PCR-amplified fragments led to the identification of four different genes, designated PcCHS1, PcCHS2, PcCHS3, and PcCHS4. By comparison of the deduced amino acid sequences, PcCHS1 was identified as a gene for class I chitin synthase, PcCHS2 and PcCHS3 were for class II, and PcCHS4 was for class III. Among these only PcCHS4 includes an intervening sequence of 56 bp. The analysis of the deduced amino acid sequences revealed a close evolutionary relationship between Penicillium and ascomycetous fungi.

Quantification of intrahepatic portosystemic shunting after placement of a transjugular intrahepatic portosystemic shunt

PURPOSE

To quantify portosystemic shunting and hepatic portal perfusion after placement of a transjugular intrahepatic portosystemic shunt (TIPS).

MATERIALS AND METHODS

Technetium-99m macroaggregated albumin (MAA) was injected directly into the portal veins of nine asymptomatic patients 3 months after TIPS placement. Portosystemic shunting was quantified by comparing counts in the lungs with those in the liver. One cirrhotic patient and one healthy patient who received portal MAA injections were used as controls.

RESULTS

No portosystemic shunting was found in the healthy patient. In the cirrhotic control patient, 77% of the injected activity was in the lungs. Patients with portosystemic shunts had even more activity in the lungs. Even stenotic shunts diverted greater than 80% of portal blood flow systemically. Flow through the TIPS ranged from 84% to 100% (average, 93%); these fractions of flow correlated inversely with portosystemic pressure gradients.

CONCLUSION

Cirrhotic livers may divert much of the portal blood systemically before TIPS placement. Afterward, this proportion rises, and most portal flow is diverted into the pulmonary circulation.

Modulation of transcriptional activity of the chicken ovalbumin gene promoter in primary cultures of chicken oviduct cells: effects of putative regulatory elements in the 5'-flanking region

With primary cultures of chicken oviduct cells, we tested functional roles in the ovalbumin gene transcription of NF-1 like factor binding element, half estrogen-response-element direct repeat, and chicken ovalbumin upstream promoter residing in the 5'-flanking region of the chicken ovalbumin gene. The three putative regulatory elements were fused upstream to the chloramphencol acetyltransferase reporter gene driven by the chicken ovalbumin gene promoters, and transient gene expression was measured in primary cultured oviduct cells. The results indicated that neither the NF1 binding element nor the ovalbumin upstream promoter showed any enhancer-like activity. In addition, although the half estrogen response element direct repeat enhanced transcriptional activity of the ovalbumin gene promoter, it completely deprived the ovalbumin promoter of estrogen dependency. We concluded, therefore, that the biological significance of these three putative regulatory elements in the homologous chicken oviduct cell system might be different from those previously reported in heterologous systems.

Effects of adenotonsillar hypertrophy on snoring in children

A prospective study was performed to evaluate the effects of adenotonsillar hypertrophy on snoring in children. Thirty male patients were grouped with respect to the severity of snoring and were evaluated in terms of the noise level of the snoring sound, the lowest arterial oxygen saturation, degree of palatine tonsillar hypertrophy, body mass index and cephalometric findings that included the adenoidal-nasopharyngeal ratio, the angle between the lines sella turcica/nasion and most posterior point of anterior maxilla/nasion, the angle between the lines sella turcica/nasion and most posterior point of anterior mandible/nasion, the posterior airway space, the distance from the sella to the nasion, lower face height and the distance from the basion to the posterior nasal spine. The noise level of the snoring sound, the lowest arterial oxygen saturation and the adenoidal-nasopharyngeal ratio showed a significant correlation with the severity of snoring, but the degree of palatine tonsillar hypertrophy and the body mass index failed to disclose any significant relationship.

Effects of running on the torsional strength, morphometry, and bone mass of the rat skeleton

Intensity and duration effects of weight-bearing exercise on the rat skeleton were investigated. Eighty-four 3-month-old female Sprague-Dawley rats were assigned to control and nine exercise groups. Exercised rats were run on a treadmill for either 30, 60, or 90 min.d-1 at low (Vo2max approximately 55%), medium (VO2max approximately 65%), or high (VO2max approximately 75%) intensity 4 d.wk-1 for 10 wk. Rat femurs, tibias, and vertebrae were harvested for torsional mechanical tests, bone density assessment, and morphometry. Our results indicate exercise has a significant effect (P < 0.05) on the femoral mechanical response (energy absorbed and twist angle), tibial morphometry (cortical bone area and thickness), and tibial and vertebral bone density measurements but had no effect (P > 0.05) on bone strength when compared with control values. Higher intensity exercise decreased tibial and femoral torque (P < 0.05). Long duration exercise increased tibial and femoral stiffness and decreased twist angle and energy absorbed (P < 0.05). These results indicate bone adapts to its loading environment by increasing bone mineral density, increasing cortical bone area, increasing stiffness, decreasing energy absorbed, and decreasing twist angle. High-intensity exercise decreased the maximum force the bone could withstand, whereas long duration exercise made the bone more brittle.

Eurysternum (extra-wide sternum)--a rarely recognized developmental anomaly. Scintigraphic appearances

A rarely recognized extra-wide sternum was demonstrated by Tc-99m methylene diphosphonate bone scans in two adult patients. One patient was a 53-year-old man with prostate cancer who had no sternal symptoms or known sternal deformity. The second patient was a 41-year-old man with carcinoma of the lung whose extra-wide sternum was associated with a pectus excavatum deformity involving the lower half of the mesosternum (corpus sternum). A proper name for this developmental abnormality, "eurysternum" (eury-Greek word meaning broad; wide), is suggested. Two other patients, one with another type of wide sternum and another with a mesosternal foramen (fenestra sternii) deformity are also described. Related embryology and developmental anatomy of the sternum are reviewed.

A GTP-binding protein regulates the activity of (1-->3)-beta-glucan synthase, an enzyme directly involved in yeast cell wall morphogenesis

Synthesis of (1-->3)-beta-D-glucan, the major structural component of the yeast cell wall, is synchronized with the budding cycle. Membrane-bound, GTP-stimulated (1-->3)-beta-glucan synthase was dissociated by stepwise treatment with salt and detergents into two soluble fractions, A and B, both required for activity. Fraction A was purified about 800-fold by chromatography on Mono Q and Sephacryl S-300 columns. During purification, GTP binding to protein correlated with synthase complementing activity. A 20-kDa GTP-binding protein was identified by photolabeling in the purified preparation. This preparation no longer required GTP for activity, but incubation with another fraction from the Mono Q column (A1) led to hydrolysis of bound GTP to GDP with a concomitant return of the GTP requirement. Thus, fraction A1 appears to contain a GTPase-activating protein. These results show that the GTP-binding protein not only regulates glucan synthase activity but can be regulated in turn, constituting a potential link between cell cycle controls and wall morphogenesis.

Effects of [(N-alkyl-1,3-dihydro-1-oxoisoindolin-5-yl)oxy]alkanoic acids on chloride transport in primary astroglial cultures

It has been demonstrated that agents which inhibit chloride influx and, therefore, lower intracellular chloride levels in the astrocyte, a major cell type in the cerebral gray matter, inhibit astrocytic swelling in vitro and in vivo. Herein, we report additional examples of a series of [(N-alkyl-1,3-dihydro-1-oxoisoindolin-5-yl)oxy]alkanoic acids and their effects upon ion transport in primary rat astrocyte cultures. The 4-chloro-substituted 1-oxoisoindolines demonstrated superior astrocytic chloride influx inhibitory activity as compared to the 6-chloro and non-chlorinated analogs. The four-carbon acid side chain derivatives were more active than the three- and two-carbon analogs. The pharmacological profile of these compounds was examined with respect to inhibition of the Cl(-)-Cl-/Cl(-)-HCO3- anion exchanger and Na(+)-K(+)-2Cl- cotransport mechanisms in glia, and the compounds were found to exhibit a similar profile to that of furosemide by inhibiting both transporters.

Ictal brain imaging in presurgical evaluation of patients with medically intractable complex partial seizures

At the Indiana University Medical Center, 99 patients with medically intractable complex partial seizures (MI-CPS) had presurgical evaluation with subsequent anterior temporal lobectomy. The majority of the patients had single photon emission tomography (SPECT) performed interictally as well as during an actual epileptic seizure (ictal scan). Decreased regional cerebral perfusion (rCP) was seen in 54/94 (57%) of the interictal scans corresponding to the eventual site of the surgery. However, ictal scans provided a higher yield; increased rCP in the temporal lobe during an actual seizure was observed in 60/82 (73%) concordant to the side of surgery. SPECT is a useful, noninvasive method of localizing the epileptiform focus in patients with MI-CPS considered for resective surgery. Both interictal and ictal SPECT need to be performed; combined interictal hypoperfusion and ictal hyperperfusion in the same focal area are unique to epileptogenic lesions. Ictal SPECT studies can be performed in the majority of patients during the period of continuous video/EEG monitoring with only a little additional effort. Combining the results of functional brain imaging (interictal and ictal SPECT, PET) with clinical semiology of seizures, surface and sphenoidal EEG, magnetic resonance imaging and other non-invasive tests, anterior temporal lobectomy can be recommended in approximately two-thirds of the patients without resorting to potentially dangerous intracranial EEG monitoring.

Conformational analysis, molecular modeling, and quantitative structure-activity relationship studies of agents for the inhibition of astrocytic chloride transport

Molecular modeling studies were carried out on a series of 1-oxoisoindolines which are pharmacologically active as inhibitors of astrocytic chloride transport. Conformational analysis revealed that the halogen substituent exerted a pronounced steric directing effect on the acid side chain. The 4-substituted analogs apparently provided for the best spatial arrangement of pharamacophoric elements of the molecules. Conventional quantitative structure-activity relationship (QSAR) studies using lipophilic and dipole moment characteristics of the molecules as physical descriptor variables in the regression equation yielded a statistically significant model. Comparative molecular field analysis (CoMFA) was utilized as a three-dimensional QSAR technique to explore changes in the steric and electrostatic fields of the molecules that can account for differences in biological activity values. A highly predictive model was attained which supported the results from the qualitative and conventional quantitative structure-activity relationship analyses. These modeling techniques represent the evolutionary process by which structure-activity methods were employed to aid in the development of novel more potent inhibitors of astrocytic chloride transport.

Influence of diagnostic radioiodines on the uptake of ablative dose of iodine-131

The uptakes of thyroablative doses of 131I by postoperative thyroid remnants and/or thyroid carcinoma metastases following diagnostic surveys with 131I or 123I were retrospectively compared by visual inspection. Only those patients with a diagnostic scan demonstrating functioning tissue, remnant, and/or metastasis, following thyroidectomy for differentiated thyroid carcinoma, were evaluated. The 131I survey group (n = 26) had received a diagnostic dose of 3 to 10 mCi of 131I. The 123I group (n = 14) had received the usual diagnostic dose of 300 microCi of 123I. The age, sex, and tumor type in the two groups were not statistically different. The uptake of the ensuing thyroablative dose of 131I appeared, by visual inspection, to be impaired in 20 of 26 patients in the 131I group and in none of the 14 patients in the 123I group (p < 0.00003). In the 131I group there was suggestion of a dose-response, that is, the higher the administered activity of 131I for the diagnostic scan, the more reduced was the subsequent apparent uptake of the thyroablative dose (p = 0.0007). Thyroid remnants or cervical lymph node metastases appeared to be affected more frequently than were the distant (pulmonary or skeletal) metastases (p = 0.004). This study suggests that iodine uptake function may be suppressed by the absorbed radiation from the 3 to 10 mCi "diagnostic" scanning dose of 131I. In this regard, 123I may be a better initial diagnostic agent to be used prior to radioablation therapy.

Scintigraphic evaluation of renovascular hypertension

ACE inhibitor challenged renal scintigraphic studies offer noninvasive means of evaluating patients for renovascular hypertension, and provide help in selecting patients who will benefit most from interventional procedures designed for alleviation of renal artery stenosis. These studies provide functional assessment of each kidney which also helps the vascular surgeons to plan which renal artery to repair first, when bilateral renal arteries are stenotic, prior to an abdominal aortic aneurysm repair. Vasotec challenged Tc99mMAG3 renal scintigraphy is one of such tests with several advantages over other similar methods, and appears to have a great potential of being a preferred scintigraphic study for evaluation of renovascular hypertension.

Changes in spectral indices of heart rate variability during exercise in acute myocardial infarction

Physical exertions are related to sudden cardiac death following acute myocardial infarction (AMI). Abnormalities in the autonomic modulation during exercise were noted in animals with AMI that were susceptible to potentially lethal arrhythmias. This study was done to evaluate the changes in the autonomic activity during exercise and recovery in AMI patients with good exercise capacity, using spectral analysis of R-R intervals of electrocardiogram (ECG). Symptom-limited treadmill exercise test was done on 17 patients of AMI with mild heart failure (in 7-10 days after the attack) and 21 healthy controls. The exercise was divided into 7 stages; rest, early exercise, mid-exercise, peak exercise, early recovery, mid-recovery, and late recovery. Power spectral analysis of R-R intervals of ECG was performed for each stage. Low frequency (0.04-0.15 Hz) and high frequency (0.15-0.40 Hz) powers, and their ratio were obtained. These parameters were observed throughout the stages in both groups. The trend of their changes during exercise and recovery was essentially the same for both groups; high and low frequency powers progressively decreased during exercise and abruptly increased during early recovery, but did not return to the values at those of rest until 9 minutes into the recovery. When the parameters were compared between the groups, there was a significantly greater decrease of high frequency power during the early exercise (p < 0.05), and a higher ratio of low to high frequency power during the early recovery (p < 0.05) in the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective study of magnetic resonance imaging and SPECT bone scans in renal allograft recipients: evidence for a self-limited subclinical abnormality of the hip

We recently reported that typical abnormalities of avascular necrosis (AVN) in magnetic resonance images (MRI) of the hips of asymptomatic renal transplant recipients whose plain radiographs are normal may improve spontaneously and even disappear completely. We present the results of serial bone scans, most of which were performed with single-photon emission computed tomography obtained over periods as long as 24 mo after transplantation in 72 of these patients. Three paired imaging studies (i.e., MR and bone scan performed within 30 days of each other) were available for each of these patients. In three patients, both the MR images and the bone scans showed changes consistent with bilateral AVN within 4 mo after transplantation. All three patients developed hip pain which was bilateral in two and unilateral in one. Two patients (three hips) required surgical intervention at which time AVN was found on pathologic examination of all three hips. None of the remaining 69 patients developed hip pain during the study. However, in nine patients whose MR studies were consistently normal, at least one bone scan was abnormal (13 hips). The presence of AVN was pathologically confirmed in each of the hips subjected to surgery. Where the imaging findings were identical to those in the asymptomatic patients as well as those in whom the imaging abnormality regressed, we suggest that the subclinical imaging abnormalities represent mild AVN, which is reversible in some cases. Since the process was identified in 10 hips by MRI and in 13 hips by bone scan, both studies are needed to detect subclinical AVN. This may be important if treatment of subclinical disease is clearly shown to prevent progression to symptomatic AVN.