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Biomedical subjects

H Tesluk

Publications and source records attributed to H Tesluk.

At least 37 records · Page 2Linked to original sources
PubMed1993

Midfacial fracture repair in the adult rat.

The consensus in the literature is that fracture healing within the midface occurs via fibrous union. Clinical experience with the surgical correction of established traumatic deformities has not borne this out. An earlier histological examination with human biopsy specimens demonstrated that eventually repair occurred by direct bony union. However, a recent study in a rabbit model challenged this conclusion and indicated that the process of new formation resembles secondary bone formation as in endochondral formed bone. The purpose of our inquiry is to elucidate further the process of midfacial bony repair in an adult male Sprague-Dawley rat model.

Animals↗
PubMed1992

Hepatic ablation with use of radio-frequency electrocautery in the animal model.

The potential of percutaneous radio-frequency (RF) electrocautery hepatic ablation was evaluated in the animal model. RF hepatic ablation was performed under ultrasound (US) guidance in the liver of 10 swine with use of a specifically designed needle. The needle was placed through the liver capsule, and ablation was performed after isolating the liver at laparotomy. Animals were killed immediately (n = 4), at 1 week (n = 1), 2 weeks (n = 3), or at 5 weeks (n = 2). The US findings were correlated with the pathologic results in the animal livers. RF hepatic ablation was successfully performed in the animal model without complications. Lesions in the animal livers were typically 1 x 2 cm, which initially appeared highly echogenic on US scans. These images corresponded to an area of hepatic necrosis. The lesions became less echogenic shortly after initial treatment but could still be visualized with US at 5 weeks. At histologic study at 5 weeks, the treated livers showed central debris, a larger area of necrotic liver, and a zone of granulation tissue surrounded by a fibrotic capsule. No complications were encountered. RF hepatic ablation shows future promise in treatment of hepatic neoplasms.

Animals↗
PubMed1992

Experimental renal embolization: preliminary results with polyacrylonitrile-based multiblock copolymers.

Preparations of polyacrylonitrile (PAN) are now being considered as possible new therapeutic embolization agents. This study evaluated two different liquid PAN formulations and a solid particle form (particle diameters, 100-400 microns). Eighteen rabbits underwent unilateral renal embolization with one of the three different preparations (n = 6 in each group). PAN was effective in causing infarcts in all embolized kidneys, which were documented with both angiograms and pathologic findings. These preliminary results show that PAN may have promise as an effective agent for clinical renal embolizations.

Acrylic Resins↗
PubMed1992

Use of biodegradable plates and screws in a rabbit model.

During the last decade, rigid internal fixation with miniplates and screws has gained widespread acceptance in the correction of both congenital and acquired craniomaxillofacial deformities. Recent studies have proposed that the currently employed metallic plates and screws may require removal because of potential facial growth restriction in growing children. Others have reported bone resorption under the plate due to stress shielding, infection, extrusion, and palpability in regions where there is minimal tissue coverage. Because these implants are radiopaque, they generate significant that interfere with radiological studies and with radiation therapy in patients undergoing treatment for malignancies. There is no question that the use of a biodegradable plating system would eliminate each of these potential or real problems, because stability is necessary only for a reasonably short period until the fracture segments have become united. We report the initial phase of a long-term study examining various materials that will be available for fabrication of a biodegradable plate and screw system. We evaluated a commercially developed biodegradable plate and screw system to treat zygomatic arch fractures in a rabbit model. Fractures were surgically created at the midpoint of each zygomatic arch. The experimental animals were then divided into three equal groups. Fractures in the first group were permitted to heal without any form of stabilization. In the second group, segments were secured with standard titanium plates and screws. Biodegradable plates and screws were employed for stabilization in the experimental group. Animals were then killed, and radiographs were obtained at 2, 4, 6, and 8 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

20 year follow-up on microinvasive squamous carcinoma of the cervix.

MISC of the cervix is a potentially fatal disease if not properly classified and treated. Strict criteria for diagnosis are required to provide appropriate therapy. It is recommended that a radical approach be considered for those patients in whom the depth of invasion of the carcinoma is greater than 3 mm on cone biopsy and in all cases where vascular invasion is demonstrated. Confluency may not of itself be a reason for more radical therapy but is an indicator of the aggressiveness of the tumor. Vascular invasion is seen more frequently with increased depth of invasion but may be found with minimal infiltration and has a serious connotation. Further refinement of the definition of MISC of the cervix appears to be needed.

Adult↗
PubMed1991

Can histological assessment predict the outcome in interstitial cystitis?

In a retrospective study we compared the outcome of 39 patients with interstitial cystitis to the histological findings at initial diagnostic bladder biopsy. The degree of inflammation and fibrosis and the mast cell counts were assessed on each biopsy. The prognostic relevance of the clinical features of age, duration of symptoms, frequency, nocturia, pain and bladder capacity was assessed. The study showed no statistical correlation between the severity of histological findings at diagnosis and the eventual outcome of the disease. Over 50% of patients with severe histological abnormalities responded to conservative treatment. Although the majority of patients with mild pathological changes responded to conservative treatment, some did require surgical intervention. The clinical features of pain, nocturia and bladder capacity showed significant differences between the 2 patient groups. However, the former 2 features are subject to many variables and the latter probably has too wide a range to be useful as a prognostic indicator. Only the response of patients to conservative treatment will indicate those who are not being helped and who may eventually require surgical treatment.

Cell Count↗
PubMed1991

Two phase radiofrequency catheter ablation of isolated ventricular endomyocardium.

UNLABELLED: This report describes a two phase radiofrequency (TPRF) energy source producing two radiofrequency sinusoidal voltages of similar frequency but different phase angles between three points of wire. When delivered through an orthogonal electrode catheter array (OECA) TPRF energy produces a square-shaped lesion of the area covered by the five electrodes (0.8 cm2). The purposes of the study were: to create square-shaped lesions using TPRF energy; to compare the size of lesions created by single phase radiofrequency (SPRF) to that of TPRF energy; and to study the depth of such lesions and to create lesions of desired size by adjacent placement of the OECA using TPRF energy. Ablations were created in nine isolated bovine hearts using three power settings (10, 20, and 40 watts) and three pulse durations (5, 10, and 20 seconds). Pathological examination was performed to document the length, width, depth, and the microscopic changes of ablations. TPRF energy increases the size of lesion (P less than 0.001) and utilizes less power (P less than 0.008) at the same power setting and pulse duration compared to SPRF energy. This is possibly related to earlier rise in impedance with TPRF compared to SPRF ablations. The largest lesion for both SPRF (0.51 +/- 0.08 cm2) and TPRF (1.03 +/- 0.18 cm2) ablations were observed at 20 watts for 20 seconds. By adjacent placement of the OECA and TPRF energy desired size (6 cm2) lesions were created. There was no significant difference between the depth of SPRF versus TPRF ablations at comparable power setting and pulse duration. Pathological examination revealed the shape of lesions were elliptical or cross-shaped for SPRF and square for TPRF ablations. Microscopic examination revealed coagulation necrosis, edema, and few necrotic cardiac muscle strands. CONCLUSIONS: TPRF energy can cause 1.2 cm2 lesions. TPRF compared to SPRF energy causes larger lesions but depth of lesions are not different than SPRF energy at the same power setting and pulse duration. By adjacent placement of OECA and TPRF energy desired size lesion can be created (6 cm2).

Animals↗
PubMed1990

Comparison of flow cytometry to routine testicular biopsy in male infertility.

We compared DNA flow cytometry to morphologic evaluation of routine testicular biopsies as methods of monitoring spermatogenesis. The study group consisted of 14 azoospermic men and 5 others who underwent testicular surgery unassociated with fertility problems. The findings for both studies were divided into three groups: normal, moderately abnormal, and markedly abnormal. Correlations between the findings from routine biopsy and flow cytometry were good. Of 9 patients having normal testicular morphology, 7 had normal ploidy classes by DNA flow cytometry while 2 had moderately abnormal histograms. Of 5 cases with moderately abnormal morphology, 1 had normal, 1 had moderately abnormal, and 3 had markedly abnormal ploidy distributions. In 5 cases described as Sertoli cell only, all DNA histograms were markedly abnormal, consisting almost exclusively of diploid cells. DNA flow cytometry of testicular biopsies and aspirates has been demonstrated to be a rapid, reproducible, and objective approach in evaluating the infertile male and is a promising method to investigate spermatogenesis in an outpatient clinic in lieu of formal testis biopsy.

Biopsy, Needle↗
PubMed1990

Recurrent interstitial cystitis following cystoplasty: fact or fiction?

The severity of symptoms in interstitial cystitis may necessitate surgical treatment in approximately 10% of the patients. Substitution cystoplasty provides satisfactory results in most of these cases, while avoiding the need for urinary diversion. It has been suggested that interstitial cystitis may affect the bowel segment used in this form of operation. We studied bowel segments removed from cystoplasties in 5 patients with interstitial cystitis and compared these to bowel used for lower urinary reconstruction for other disorders in 6 patients. All segments showed varying degrees of inflammation, fibrosis and mastocytosis but there was no difference between the 2 groups for these features. We conclude that inflammation and fibrosis is the usual reaction of bowel to exposure to urine, and they do not represent a specific spread of interstitial cystitis in those patients. However, this reaction does mimic the histological appearance of interstitial cystitis in the bladder and may suggest a model for this disease.

Adult↗
PubMed1990

The split calvarial bone graft donor site: the effects of surgicel and hydroxyapatite impregnated with collagen.

Surgicel, which is commonly used as a hemostatic agent in clinical practice, is basically composed of oxidized regenerated cellulose. Skoog followed by Thilander and Stenstrom are credited with initially describing the use of Surgicel as a subperiosteal implant that could stimulate new bone formation in the closure of secondary palatal fistulae. Encouraged by these previous studies, we decided to investigate the effect of Surgicel and a new implant material, hydroxyapatite impregnated with collagen, on the split calvarial bone graft donor site. To do this, we used adult New Zealand White rabbits as our experimental model. Our study demonstrated histological evidence of both an increased quantity and earlier bony reformation, eventually reconstituting the surgical defect in the split calvarial bone graft donor site treated with Surgicel. Additionally, we found that this alloplastic implant material has potential in the reconstruction of the donor defect in selected patients.

Animals↗
PubMed1990

Quantitative DNA patterns in human preneoplastic breast lesions.

In 12 cases of human mammary carcinoma in which a preneoplastic atypical ductal hyperplasia was also identified, quantitative DNA (QDNA) measurements of thionein-stained samples from both lesions were performed using the Cell Image Analysis 100 system. The QDNA values in the preneoplastic and neoplastic lesions from each case showed concordance (six as euploid and six as aneuploid/hyperdiploid). Such congruence suggests a stable inheritance of the somatic mutation(s) that is involved in carcinogenesis and that affects ploidy. If this relationship between concurrent preneoplasia and neoplasia in the ipsilateral breast is confirmed, it offers the possibilities of (1) identifying individuals at risk for developing neoplasias with defined biologic characteristics and (2) developing therapeutic regimens more appropriate to the risk assessment of each patient. It may be possible to conceive of a rational preventive regimen for cancer of the breast.

Breast↗
PubMed1988

Dissolution of gallstones using methyl tertiary-butyl ether in an animal model.

Human gallstones were surgically implanted in the gallbladders of six pigs. Through cholecystostomy catheters, methyl tertiary-butyl ether (MTBE) was infused from 3 to 5 days. MTBE successfully dissolved 19 of the 20 cholesterol stones and partially dissolved one mixed cholesterol-bilirubin stone. Gross and microscopic examination of abdominal organs revealed mild superficial ulcerations of the gallbladder and mild to moderate chronic inflammatory changes in the gallbladder of animals treated with MTBE infusion. There were no other significant changes within other abdominal organs except for mild inflammation of the duodenum in one animal and of the common bile duct in another. Because of its efficacy and limited deleterious effects, MTBE may be a good solvent when dissolving pure cholesterol gallstones in the gallbladder.

Animals↗
PubMed1987

Cystic dysplasia of testis.

A rare developmental disorder, cystic dysplasia of the testis, encountered in a newborn infant, is described. The relationship to renal dysplasia and the recent literature are reviewed.

Cysts↗
PubMed1987

Dissolution of gallstones using cholecystostomy tube in the pig.

Cholecystostomy catheters and human cholesterol gallstones were implanted surgically in the gallbladders of eight pigs. Through the catheters, mono-octanoin or sterile water (H2O) was infused from two to seven days. The mono-octanoin dissolved pure cholesterol gallstones smaller than 200 g. There was no stone dissolution with infusion of sterile water and only one stone larger than 250 g was dissolved with mono-octanoin. Side effects included moderate-to-severe inflammation and ulceration of the gallbladder with mono-octanoin instillation, which precludes its widespread use with the present treatment regimen. Infusion of water caused little gallbladder irritation.

Animals↗