Regulation of KChIP2 potassium channel beta subunit gene expression underlies the gradient of transient outward current in canine and human ventricle

Expression of four members of the KChIP family of potassium channel beta subunits was examined in canine heart. Only one member of the gene family, KChIP2, was expressed in heart. There was a steep gradient of KChIP2 mRNA expression across the canine ventricular free wall. KChIP2 mRNA was 25-fold more abundant in the epicardium than in the endocardium, and this gradient paralleled the gradient in transient outward current (Ito) expression. In contrast, Kv4.3 potassium channel alpha subunit mRNA was expressed at equal levels across the ventricular wall. There was no difference in the pharmacological sensitivity of epicardial and endocardial Ito channels to flecainide, suggesting that the current is produced by the same channel in the two tissues. A similar gradient of KChIP2 expression was found across the ventricular wall of human heart, but not rat heart. It is concluded that transcriptional regulation of the KChIP2 beta subunit gene, rather than the Kv4.3 [alpha] subunit gene, is the primary determinant regulating the transmural gradient of Ito expression in the ventricular free wall of canine and human heart.

The inhibitory effects of colchicine on cell proliferation and mineralisation in culture

Colchicine is often used in the treatment of diseases such as familial Mediterranean fever (FMF) and gout. We have previously reported that patients with FMF who had colchicine on a daily basis and who had a total hip arthroplasty showed no heterotopic ossification after surgery. The mechanism by which colchicine causes this clinical phenomenon has never been elucidated. We therefore evaluated the effect of various concentrations of colchicine on cell proliferation and mineralisation in tissue culture, using rat and human cells with and without osteogenic potential. Cell proliferation was assessed by direct cell counts and uptake of (3H)thymidine, and mineralisation by measuring the amount of staining by Alizarin Red. Our findings indicate that concentrations of colchicine of up to 3 ng/ml did not affect cell proliferation but inhibition was observed at 10 to 30 ng/ml. Mineralisation decreased to almost 50%, which was the maximum inhibition observed, at concentrations of colchicine of 2.5 ng/ml. These results indicate that colchicine at low concentrations, of up to 3 ng/ml, has the capacity to inhibit selectively bone-like cell mineralisation in culture, without affecting cell proliferation. Further clinical and laboratory studies are necessary to evaluate the effects of colchicine on biological processes involving the proliferation of osteoblasts and tissue mineralisation in vivo, such as the healing of fractures, the formation of heterotopic bone and neoplastic bone growth.

Ultrastructure of the lamellar corneal wound after laser in situ keratomileusis in human eye

A 30-year-old patient with keratoconus, a stable refraction, and normal central corneal thickness had laser in situ keratomileusis (LASIK). Six months later, she had uneventful penetrating keratoplasty for keratectasia. The lamellar LASIK interface could not be clearly identified by light microscopy. The corneal wound site did not stain for methyl metalloproteinase 1 or 2. Both the corneal flap undersurface and the stromal bed were devoid of interconnections and cells. Throughout the lamellar incision, including the laser-ablated zone, the surface was smooth on scanning electron microscopy. The collagen fibrils on both sides of the incision remained well aligned with one another, indicating good flap apposition. Under higher magnification transmission electron microscopy, some collagen fragments were found in the interface, especially adjacent to the hinge. The diameter of the collagen fibrils along the lamellar wound were identical to those farther from the incision. The absence of bridging collagen fibrils and cells between the flap undersurface and the stromal bed confirms the clinically known lack of wound repair at the interface and explains the easy separation of the flap from the stromal bed months after LASIK and the possible formation of an interface fluid pocket.

The inhibitory effects of colchicine on cell proliferation and mineralisation in culture

Colchicine is often used in the treatment of diseases such as familial Mediterranean fever (FMF) and gout. We have previously reported that patients with FMF who had colchicine on a daily basis and who had a total hip arthroplasty showed no heterotopic ossification after surgery. The mechanism by which colchicine causes this clinical phenomenon has never been elucidated. We therefore evaluated the effect of various concentrations of colchicine on cell proliferation and mineralisation in tissue culture, using rat and human cells with and without osteogenic potential. Cell proliferation was assessed by direct cell counts and uptake of (3H)thymidine, and mineralisation by measuring the amount of staining by Alizarin Red.

Our findings indicate that concentrations of colchicine of up to 3 ng/ml did not affect cell proliferation but inhibition was observed at 10 to 30 ng/ml. Mineralisation decreased to almost 50%, which was the maximum inhibition observed, at concentrations of colchicine of 2.5 ng/ml. These results indicate that colchicine at low concentrations, of up to 3 ng/ml, has the capacity to inhibit selectively bone-like cell mineralisation in culture, without affecting cell proliferation. Further clinical and laboratory studies are necessary to evaluate the effects of colchicine on biological processes involving the proliferation of osteoblasts and tissue mineralisation in vivo, such as the healing of fractures, the formation of heterotopic bone and neoplastic bone growth.

Achilles tendon pain and related pathologies: diagnosis by ultrasonography

BACKGROUND

When encountering complaints of pain in the area of the Achilles tendon, the clinician seldom reaches a correct and precise diagnosis based solely on the grounds of physical examination and standard X-rays.

OBJECTIVES

To assess the usefulness of ultrasound in diagnosing pathologies of the Achilles tendon.

METHODS

We conducted a retrospective review of patients presenting at our orthopedic clinics.

RESULTS

Sonography was used to evaluate 41 patients with achillodynia. This modality enabled the diagnoses of 19 abnormal tendons (46%), peritendinous and other lesions; a complete rupture in two patients (5%); a partial rupture of the Achilles tendon in 3 (7%); various degrees of calcification of the tendon in 7 (17%); and peritendinous lesions discerned by the tendon's hypoechoic regions with disorganized arrangement of collagen fibrils in 4 patients (10%). Other lesions included tendonitis (3 patients, 7%), retrocalcaneal bursitis (3 patients, 7%), lipoma (1 patient, 2%), and foreign bodies (2 patients, 5%). The mean diameter of the pathological tendons was 10.4 +/- 2.7 mm, while normal tendons measured 5.2 +/- 0.8 mm (P < 0.001).

CONCLUSION

As in many other soft tissue lesions, ultrasonography is a useful tool in the evaluation of the underlying pathology in patients presenting with achillodynia.

The adenine nucleotide translocator: a target of nitric oxide, peroxynitrite, and 4-hydroxynonenal

Nitric oxide (NO), peroxynitrite, and 4-hydroxynonenal (HNE) may be involved in the pathological demise of cells via apoptosis. Apoptosis induced by these agents is inhibited by Bcl-2, suggesting the involvement of mitochondria in the death pathway. In vitro, NO, peroxynitrite and HNE can cause direct permeabilization of mitochondrial membranes, and this effect is inhibited by cyclosporin A, indicating involvement of the permeability transition pore complex (PTPC) in the permeabilization event. NO, peroxynitrite and HNE also permeabilize proteoliposomes containing the adenine nucleotide translocator (ANT), one of the key components of the PTPC, yet have no or little effects on protein-free control liposomes. ANT-dependent, NO-, peroxynitrite- or HNE-induced permeabilization is at least partially inhibited by recombinant Bcl-2 protein, as well as the antioxidants trolox and butylated hydroxytoluene. In vitro, none of the tested agents (NO, peroxynitrite, HNE, and tert-butylhydroperoxide) causes preferential carbonylation HNE adduction, or nitrotyrosylation of ANT. However, all these agents induced ANT to undergo thiol oxidation/derivatization. Peroxynitrite and HNE also caused significant lipid peroxidation, which was antagonized by butylated hydroxytoluene but not by recombinant Bcl-2. Transfection-enforced expression of vMIA, a viral apoptosis inhibitor specifically targeted to ANT, largely reduces the mitochondrial and nuclear signs of apoptosis induced by NO, peroxynitrite and HNE in intact cells. Taken together these data suggest that NO, peroxynitrite, and HNE may directly act on ANT to induce mitochondrial membrane permeabilization and apoptosis.

Ultrasonography: an imaging modality enabling the diagnosis of bipartite patella

Ultrasound was used to diagnose bipartite patella in seven adolescents with anterior knee pain, and the findings were compared to those from plain radiography and to those of a group of asymptomatic subjects. In all affected individuals the quadriceps and patellar tendons appeared normal on ultrasound. Sonographic examination of the patella demonstrated an irregularity of the bony contour with occurrence of a cleft between the main part of the patellar body and the large superolateral accessory ossicle. The signal detected in the interface between bones was less echogenic than bone reflecting its fibrocartilaginous nature. The correlation with conventional radiography was absolute, as was the inter- and intraobserver reliability. Ultrasound is thus proposed as a simple and reliable imaging modality in bipartite patella. We do not believe that it should replace the initial radiographic, but it can be used to evaluate the contralateral knee for bilaterality and as an adjunct to therapeutic procedures such as local injections to increase the accuracy of treatment.

Mechanism of GnRH receptor signaling on gonadotropin release and gene expression in pituitary gonadotrophs

Gonadotropin releasing hormone (GnRH), the first key hormone of reproduction, is synthesized and secreted from the hypothalamus in a pulsatile manner and stimulates pituitary gonadotrophs (5-10% of the pituitary cells) to synthesize and release gonadotropin luteinizing hormone (LH) and follicle stimulating hormone (FSH). Gonadotrophs consist of 60% multihormonal cells (LH+FSH) and 18% LH- and 22% FSH-containing cells. LH and FSH, members of the glycoprotein hormone family, stimulate spermatogenesis, folliculogenesis, and ovulation. Although GnRH plays a pivotal role in gonadotropin synthesis and release, other factors such as gonadal steroids and gonadal peptides exert positive and negative feedback mechanisms, which affect GnRH actions. GnRH actions include activation of phosphoinositide turnover as well as phospholipase D and A2, mobilization and influx of Ca2+, activation of protein kinase C (PKC) and mitogen-activated protein kinase (MAPK). A complex crosstalk between the above messenger molecules mediates the diverse actions of GnRH. Understanding the signaling mechanisms involved in GnRH actions is the basis for our understanding of basic reproductive functions in general and gonadotropin synthesis and release in particular.

Ultrasonography as a diagnostic modality and therapeutic adjuvant in the management of soft tissue foreign bodies in the lower extremities

BACKGROUND

Foreign bodies are sometimes overlooked in the initial evaluation of soft tissue wounds in the emergency room setting. The physical examination identifies foreign bodies that are superficial enough to be seen or palpated, while radiographs reveal those that are radio-opaque. If these two criteria are not met, however, the foreign body may remain undetected. These patients present later with long-standing pain in the area of penetration sometimes associated with localized tenderness.

OBJECTIVES

To assess the role of ultrasonography in the diagnosis and management of patients with a suspected retained foreign body.

METHODS

Ultrasound was used in 21 patients with suspected retained foreign bodies and the diagnosis was positive in 19. Fifteen underwent a surgical exploration in which the ultrasound was used as an adjunctive modality either pre- or intraoperatively to assist in the localization of the foreign body.

RESULTS

All procedures were successful. No postoperative complications were recorded at an average follow-up of 2 years. Three patients gradually became asymptomatic and were left untreated. One patient was lost to follow-up.

CONCLUSION

Sonography is an extremely effective tool for the late diagnosis of retained foreign bodies in the soft tissues. We suggest that its availability in the emergency room may decrease the rate of misdiagnosis and avoid these unfortunate cases, although this remains to be proven.

Prediction of myocardial infarction versus cardiac death by gated myocardial perfusion SPECT: risk stratification by the amount of stress-induced ischemia and the poststress ejection fraction

The combination of myocardial perfusion and poststress ejection fraction (EF) provides incremental prognostic information. This study assessed predictors of nonfatal myocardial infarction (MI) versus cardiac death (CD) by gated myocardial SPECT and examined the value of integrating the amount of ischemia and poststress EF data in risk stratification.

METHODS

We identified 2,686 patients who underwent resting (201)Tl/stress (99m)Tc-sestamibi gated SPECT and were monitored for >1 y. Patients who underwent revascularization < or = 60 d after the nuclear test were censored from the prognostic analysis. Visual scoring of perfusion images used 20 segments and a scale of 0--4. Poststress EF was automatically generated.

RESULTS

Cox regression analysis showed that after adjusting for prescan data, the most powerful predictor of CD was poststress EF, whereas the best predictor of MI was the amount of ischemia (summed difference score [SDS]). Integration of the EF and SDS yielded effective stratification of patients into low-, intermediate-, and high-risk subgroups. Patients with EF >50% and a large amount of ischemia were at intermediate risk (2%--3%), whereas those with mild or moderate ischemia were at low risk of CD (<1%/y). Patients with EF between 30% and 50% were at intermediate risk even in the presence of only mild or moderate ischemia. In patients with EF <30%, the CD rate was high (>4%/y) irrespective of the amount of ischemia.

CONCLUSION

Poststress EF is the best predictor of CD, whereas the amount of ischemia is the best predictor of nonfatal MI. Integration of perfusion and function data improves stratification of patients into low, intermediate, and high risk of CD.

Granulosa cell tumors of the ovary: do they have any unique ultrasonographic and color Doppler flow features?

The aim of this study was to describe the ultrasonographic and Doppler flow attributes of granulosa cell tumors (GCT) of the ovary and to compare these attributes to those of epithelial tumors of the ovary. Among 13,475 gynecological patients who were scanned in our ultrasound unit between 1992 and 1996, seven patients had GCT. The final diagnosis was confirmed, postoperatively, by pathologic examination and by applying the WHO classification. The ultrasonographic findings of the GCT patients were compared to those recorded in a second group of 29 patients who had been diagnosed with epithelial tumor of the ovary. The sonographic appearance of GCT of the ovary was semi-solid and the endometrium was thick in six of the seven patients. Doppler flow studies of vessels within or in the contour of the lesions showed the resistive index (RI) to be 0.448 +/- 0.018. The epithelial tumors had a similar appearance and flow pattern except for the presence of ascites in one-third of the patients. Ultrasound scanning, including color Doppler flow, did not contribute data that could assist in differentiating between GCT and epithelial tumors of the ovary.

Using selective withdrawal to coat microparticles

We report a method that uses the process of selective withdrawal of one fluid through a second immiscible fluid to coat small particles with polymer films. Fluid is withdrawn through a tube with its orifice slightly above a water-oil interface. Upon increasing the flow rate, there is a transition from a state where only oil is withdrawn to a state where the water, containing the particles to be coated and appropriate prepolymer reagents, is entrained in a thin spout along with the oil. The entrained particles eventually cause the spout interface to break, producing a thin coat of controllable thickness around each particle, which can be subsequently polymerized using chemical reagents, light, or heat. This method allows flexibility in the chemical composition and thickness of the conformal coatings.

Comparison of endometrial pathologies collected by hysteroscopy and hysterectomy in postmenopausal breast cancer tamoxifen-treated patients

PURPOSE OF INVESTIGATION

1) To assess whether endometrial specimens obtained from removed uteri might show an increase in endometrial pathologies which had been previously diagnosed by hysteroscopy in postmenopausal breast cancer tamoxifen-treated patients. 2) To assess whether hysteroscopy is an efficient method of detecting endometrial pathologies in such patients.

METHODS

The findings of two consecutive pathological evaluations in 18 postmenopausal breast cancer tamoxifen-treated patients, performed 11.2+/-11.2 months apart, were compared. The first specimen was collected by hysteroscopy and the second was obtained following hysterectomy.

RESULTS

The most significant changes observed were three new cancers diagnosed at hysterectomy, one of which was poorly-differentiated. In the first (hysteroscopy) samplings, one patient had atrophic endometrium, a second patient had endometrial proliferation and a third patient had a benign endometrial polyp. Overall, 55.6% of the study patients had various endometrial pathologies in the first sampling, while 83.3% had endometrial pathologies in the second sampling. However, this difference was not statistically significant.

CONCLUSION

1) Endometrial histologic evaluations, performed on removed uteri 11.2+/-11.2 months following previous endometrial samplings of postmenopausal breast cancer tamoxifen-treated patients, showed a non-significant risk of developing overall endometrial pathologies. 2) Hysteroscopy may have missed some endometrial pathologies which were diagnosed later on in specimens obtained by hysterectomy.

Localization, detection and guided removal of soft tissue in the hands using sonography

Penetrating wounds and lacerations are frequent pathologies treated in the emergency room. The management of hand trauma represents a large part of the work in any surgical practice. Although X-rays are routinely taken, numerous foreign bodies remain undetected, and the wounds are just locally debrided and the lacerations sutured. Unfortunately, as not all foreign bodies are radio-opaque, the radiography results may appear normal, but the patient fails to recover. Patients complaining of persistent wound tenderness were sent for ultrasound investigations, and foreign bodies were detected. Had ultrasonography been carried out initially in the emergency room, the correct diagnosis would have been made, and the sonographic equipment could have helped to guide the physician in his attempt to remove the foreign body. Usually, in response to continued pain, an ultrasound investigation is ordered, and the pathology becomes apparent. A number of examples are briefly described in order to highlight the present inadequacies. It is suggested that hospital administrators consider the need to provide ultrasonographic services as an integral facility of the emergency room.

Pelvic actinomycosis presenting as ureteric and rectal stricture

BACKGROUND/AIMS

Simultaneous ureteric and rectal stricture due to pelvic actinomycosis is very rare and only a few cases of either rectal or ureteric stricture have been reported. Our aim is to report a case of stricture of the rectum and the right ureter due to pelvic actinomycosis infection in a 63-year-old man.

METHODS

Explorative laparotomy and biopsies of the inflammatory pelvic mass were the only procedures that led to the definitive diagnosis of actinomycosis. Temporary diverting colostomy, drainage of the right ureter by a pigtail catheter and postoperative treatment with appropriate antibiotics were successful in eradicating the inflammatory process.

CONCLUSIONS

Extensive pelvic masses involving pelvic viscera should be biopsied before undertaking any major surgery because of the possibility of pelvic actinomycosis.

The N-terminal domain of rat liver carnitine palmitoyltransferase 1 contains an internal mitochondrial import signal and residues essential for folding of its C-terminal catalytic domain

We have previously shown that the first 147 N-terminal residues of the rat liver carnitine palmitoyltransferase 1 (CPT1), encompassing its two transmembrane (TM) segments, specify both mitochondrial targeting and anchorage at the outer mitochondrial membrane (OMM). In the present study, we have identified the precise import sequence in this polytopic OMM protein. In vitro import studies with fusion and deletion CPT1 proteins demonstrated that none of its TM segments behave as a signal anchor sequence. Analysis of the regions flanking the TM segments revealed that residues 123-147, located immediately downstream of TM2, function as a noncleavable, matrix-targeting signal. They specify mitochondrial targeting, whereas the hydrophobic TM segment(s) acts as a stop-transfer sequence that stops and anchors the translocating CPT1 into the OMM. Heterologous expression in Saccharomyces cerevisiae of several deleted CPT1 proteins not only confirms the validity of the "stop-transfer" import model but also indicates that residues 1-82 of CPT1 contain a putative microsomal targeting signal whose cellular significance awaits further investigation. Finally, we identified a highly folded core within the C-terminal domain of CPT1 that is hidden in the entire protein by its cytosolic N-terminal residues. Functional analysis of the deleted CPT1 proteins indicates that this folded C-terminal core, which may belong to the catalytic domain of CPT1, requires TM2 for its correct folding achievement and is in close proximity to residues 1-47.

Tamoxifen modulates apoptotic pathways in primary endometrial cell cultures

Clinical data indicate that tamoxifen (TAM) therapy may cause an increased risk of endometrial pathology in postmenopausal but not in premenopausal women. Molecular mechanisms of the uterotrophic activity of TAM have not been clearly established nor its relevance to apoptosis in endometrial cells. The present study was implemented to evaluate the apoptotic effect of TAM on primary endometrial cell cultures in the presence or absence of steroid hormones (SHs). A total of 14 primary endometrial cell cultures were established and maintained both with and without SHs. Cell cultures were treated for 24 h with either 20 microM TAM or 10 nM estradiol. Apoptotic cells presented in a pre-G1 peak and the expression of bcl-2 were studied using flow cytometry. All endometrial cell cultures maintained in a SH-containing environment, except one, responded to TAM by a significant increase (P = 0.03) in the pre-G1 cell fraction, indicating a proapoptotic effect. A significant (P = 0.03) reduction in the pre-G1 peak equivalent to an antiapoptotic response was observed in 6 of 13 cell cultures maintained in a SH-deficient environment. In 4 of 10 cell cultures evaluated in both media, the pre-G1 population was medium dependent. In 8 of 10 cultures evaluated for Bcl2 levels, no trend was found in either media, but a dependency on SH content was observed. Comparison between effects of TAM and estradiol demonstrated identical trends, regardless of the menstrual phase or SH content in cell environments. These results suggest that TAM acts as an estrogen agonist on endometrial tissue in both environments. We conclude that TAM modulates apoptotic pathways in primary endometrial cell cultures. The SH content in the cell environment influences the apoptotic effect of TAM and determines the propensity for a cell to undergo apoptosis or, on the contrary, to resist apoptotic death in response to TAM treatment. This is in concordance with the observed clinical risk of endometrial pathologies in postmenopausal versus premenopausal women.

Complementary and alternative medicine in early-stage breast cancer

Complementary and alternative medicine (CAM) are becoming increasingly popular in many medical situations, particularly among patients with cancer. CAM encompasses a range of modalities including dietary and vitamin supplements, mind-body approaches, acupuncture, and herbal medicines. In contrast to standard chemotherapeutic and hormonal regimens used for the adjuvant treatment of early-stage breast cancer, controlled clinical trials have generated few data on the relationship between CAM and the outcomes of recurrence or survival, or even overall quality of life and safety. The objectives of CAM treatments are manifold: the reduction of toxicities of therapy, improvement in cancer-related symptoms, enhancement of the immune system, and even a direct anticancer effect. The primary basis of CAM rests on empirical evidence and case studies, as well as theoretic physiologic effects. In some cases, laboratory or clinical data lend support to these modalities. Some types of CAM are based on ancient Oriental forms of medicine founded on centuries of experience documented through oral and written text. Nevertheless, the paucity of evidence in the clinical setting limits firm conclusions about the effectiveness or safety of most CAM approaches in breast cancer. This review will summarize the basis for the application of certain CAM modalities in the therapy of early-stage breast cancer and will highlight some of the directions of investigative work that could lead to a rational integration of CAM into conventional adjuvant therapy.

Corneal co-infection with Scedosporium apiospermum and Acanthamoeba after sewage-contaminated ocular injury

PURPOSE

To describe a corneal co-infection with the fungus Scedosporium apiospermum and Acanthamoeba that result in spontaneous corneal perforation.

METHODS

A 27-year-old man presented due to severe ocular pain in his left eye caused by a corneal ulcer. The patient was injured 7 days before presentation by metallic thread contaminated by sewage. Corneal scrapping and deep stromal biopsy were obtained and stained for microscopic evaluation with periodic acid-Schiff, Giemsa, and Gomori's methenamine silver stains. Samples were sent for aerobic and anaerobic bacterial and fungal cultures.

RESULTS

Corneal biopsy and corneal scrapping showed viable Acanthamoeba cysts in the corneal stroma and S. apiospermum micelle, respectively. The fungal culture was sensitive to ketoconazole, miconazole, econasole, and traconazole. Devastating corneal perforation occurred despite aggressive antifungal and antiamoebic topical and systemic treatment initiated after diagnosis. The corneal button showed a necrotic tissue devoid of inflammatory cells and microorganisms.

CONCLUSION

S. apiospermum and Acanthamoeba may co-infect immune privilege sites, such as the cornea, in immunocompetent hosts. Compromised corneal surface, e.g., after trauma by sewage-contaminated objects, may increase the susceptibility for such devastating coinfection. Prevention may be possible by use of protective eyewear by high-risk individuals. Treatment should be initiated promptly with broad-spectrum antimicrobial agents after ocular injury by sewage-contaminated objects. Repeated corneal cultures and biopsies, if the cultures are negative, are warranted. Corticosteroids should be withheld until the causative agents are identified and targeted treatment is initiated.

Self-organization in systems of self-propelled particles

We investigate a discrete model consisting of self-propelled particles that obey simple interaction rules. We show that this model can self-organize and exhibit coherent localized solutions in one- and in two-dimensions. In one-dimension, the self-organized solution is a localized flock of finite extent in which the density abruptly drops to zero at the edges. In two-dimensions, we focus on the vortex solution in which the particles rotate around a common center and show that this solution can be obtained from random initial conditions, even in the absence of a confining boundary. Furthermore, we develop a continuum version of our discrete model and demonstrate that the agreement between the discrete and the continuum model is excellent.