Biomedical subjects

K Kula

Publications and source records attributed to K Kula.

At least 19 recordsLinked to original sources

PubMed2002

Clinical bond failure of pre-coated and operator-coated orthodontic brackets.

OBJECTIVES: To test the hypothesis that there is no significant difference in clinical bracket failure between the 3M APC Mini Twin bracket system and the Transbond XT adhesive during orthodontic treatment. DESIGN: A randomized, split mouth, prospective clinical trial. SETTING AND SAMPLE POPULATION: The Department of Orthodontics and Dentofacial Orthopedics at University of Missouri, Kansas City. Twenty-nine subjects who were treatment planned to receive comprehensive orthodontics using 0.018 slot appliances. EXPERIMENTAL VARIABLE: The adhesive pre-coated brackets (APC) system was randomly assigned to one side of the mouth and the Transbond XT was assigned to the opposite side. OUTCOME MEASURE: The absence of any of the brackets at the time of a regular or emergency orthodontic appointment. RESULTS: There was no significant difference (P > 0.05) in bracket failure between the 3M APC Mini Twin bracket system and the Transbond XT adhesive at any time period (90, 180, or 365 days). The failure rate of brackets on premolars was higher than on incisors or canines. CONCLUSION: APC Mini Twin bracket system and Transbond XT adhesive are equally effective in maintaining brackets clinically. Inexperienced operators had an overall 7.5% bond failure 12 months following bracket placement.

Acrylic Resins↗

PubMed2001

Estradiol enhances the stimulatory effect of FSH on testicular maturation and contributes to precocious initiation of spermatogenesis.

Male rats were daily injected with human FSH (hFSH) or estradiol benzoate (EB) or hFSH+EB between day 5 and 15 of life and autopsied on day 16. hFSH accelerated testicular growth, increased number of spermatogonia and serum level of testosterone. hFSH stimulated also spermatogonia differentiation, which resulted in 5-fold increase of the number of spermatocytes. EB given alone induced adverse, inhibitory effects on spermatogenesis and serum testosterone, did not influence serum FSH and LH but increased 14-fold the level of prolactin. Except from testosterone, EB given with hFSH not only overcame inhibitions, but multiplied hFSH stimulatory effects on spermatogenesis up to 30-times of control values. In addition, after FSH+EB premeiotic germ cell ratio reached adult type value precociously. Estradiol may play regulatory roles in testicular maturation (1) inhibitory, direct one or resulting from decrease in testosterone secretion; (2) stimulatory, by enhancement of FSH action, with a possible involvement of prolactin that may act in concert with FSH.

Animals↗

PubMed2001

Immunohistochemical diagnosis of preinvasive germ cell cancer of the testis.

The aim of the study was to identify testicular carcinoma in situ (CIS), a precursor of germ cell tumours (GCT), in patients from the high risk groups, using classic and alternative immunohistochemical methods. 70 patients with 46,XY karyotype were examined. Whole gonads or biopsy specimens were fixed in Bouin's fluid. In cases with dysgenetic male pseudohermaphroditism (DMP), gross histopathology revealed sex cord tumour gonadoblastoma in 4 and malignant dysgerminoma in 1 out of 23 patients. In all patients, paraffin sections were treated with antibodies against placental-like alkaline phosphatase (PLAP), a classic immunohistochemical marker of GCT and CIS. CIS was detected immunohistochemically in 10 out of 23 cases with DMP (43.5%), in 1 out of 10 cases with androgen insensitivity syndrome (10%), in 3 out of 18 cases operated previously because of already developed GCT in contralateral testis (16.6%) and in 1 out of 3 patients with cryptorchidism in anamnesis (33.3%). CIS was not found in 16 examined adult infertile men with azoospermia. In addition to PLAP investigation, 12 cases with DMP and 6 cases with GCT were examined using M2A and TRA-1-60 antibodies, the alternative immunohistochemical markers of CIS. While in DMP positive reactions for M2A and TRA-1-60 accompanied PLAP reaction in 1/3 of cases, M2A accompanied PLAP in all cases with GCT. The positive reaction for TRA-1-60 accompanied PLAP and M2A in 1 case with GCT. The results indicate that among different risk groups the highest incidence of CIS occurs in DMP. Screening for CIS is of importance also in cryptorchidism, androgen insensitivity syndrome and in men who underwent gonadectomy because of unilateral GCT. The immunostaining for PLAP seems to be more discriminative procedure. The positive staining of CIS cells with M2A and TRA-1-60 antibodies may be indicative for more advanced neoplastic transformation.

Adolescent↗

PubMed2000

[Sexual differentiation of the human brain].

Normal human development requires the compatibility between genetic sex (sex chromosomes), sex of gonades (tests or ovaries), genitalia (external and internal sex organs), somatic features (body characteristics) and psychic sex. The psychic sex, called frequently gender, consist of gender identity (self-estimation), gender role (objective estimation) and sexual orientation (hetero- or homosexual). It was believed that the psychic gender depends only on socio-environmental influences such as rearing, learning and individual choice. Although, the process of sexual differentiation of human brain is not completely elucidated, it has became recently evident that endogenous hormones more then socio-environmental factors influence gender differences. Experimental studies on animals revealed that transient action of sex steroids during perinatal period of life is crucial for the dymorphism of sexual behavior (male or female) in adulthood. It seems, that also in the human male neonates testosterone produced by testes perinatally takes the main role in the irreversible masculinization of the brain i.e. creation of the differences vs. female brain. The evaluation of patients with disturbances of sexual differentiation of external genitalia (the lack of the testosterone transformation into 5-alpha dihydrotestosterone in peripheral tissues of men or the inborn excess of androgens in women with the congenital adrenal hyperplasia) has served as a useful clinical model for understanding factors, affecting the formation of gender. In these individuals the formal sex established according to genetic sex and somatic sex may be incompatible with gender identity and role. However, it has been found that the female gender identity is most frequently associated with the presence of ovaries or the lack of gonads (gonadal dysgenesis), while the male gender identity appear most frequently in the presence of testicular tissue irrespective of female or hermaphrodite (intersex) phenotype. In genetic men with the absence of male genitalia formation, caused by the aberrant function of androgen receptor, the gender identity depends on the severity of the disorder: female gender identity in the complete androgen insensitivity syndrome and female or male gender identity in the complete androgen insensitivity syndrome and female or male in the partial androgen insensitivity. These clinical observations confirm the experimental data indicating androgen role in the male gender identity creation. This knowledge is necessary for the decision of the direction of surgical correction of sex organs in children with ambiguous genitalia, which should not depend on the expected efficiency to perform sexual intercourse, but mostly on the expected or already present individual gender identity.

Animals↗

PubMed2000

Reasons that orthodontic faculty teach and consider leaving teaching.

To assess reasons why orthodontic faculty consider leaving academia, a pretested questionnaire was mailed to 200 full-time (FT) and 200 part-time (PT) faculty randomly selected from the United States and Canada. A total of 144 (72 percent) of FT and 120 (60 percent) PT responded. About 38 percent FT and 25 percent PT were currently considering leaving academia. The average age of each group was about fifty years. Although significant differences were found in fifteen factors affecting the decision to leave, three factors ranked as most important (means> or =3.4) for FTs: salary support, financial support of department, and control over work or destiny. The three factors most important (means>3. 1) for PTs were: challenge of private practice, family commitments, and personal. FT and PT were similar in the most important and least important factors influencing their initial reasons to teach and satisfaction in teaching. However, the reasons why FT considered leaving were work related, while the PT's reasons were more personal. With the current shortage of FT orthodontic faculty becoming imminently greater, it appears that work-related issues could be addressed directly by administration.

Adult↗

PubMed1999

[Normal pregnancy after laser salpingostomy, blighted ovum, and right tubal pregnancy treated with methotrexate].

The 8-years lasting primary infertility in 28 years old woman was caused by bilateral hydrosalpinx, anovulation and husband's oligozoospermia. CO2 laser salpingostomy, treatment of the husband and ovulation induction with clomiphene citrate were successful. The consecutive pregnancies were achieved: 1. blighted ovum, 2. right tubal pregnancy cured with (MTX), 3. normal pregnancy.

Abortifacient Agents, Nonsteroidal↗

PubMed1998

Effect of ion implantation of TMA archwires on the rate of orthodontic sliding space closure.

A split-mouth randomized clinical trial was used to determine whether ion implantation of beta-titanium archwire would facilitate sliding space closure. After bilateral maxillary first premolar extractions, 0.19 x 0.025-inch beta-titanium arch wires, ion-implanted on one half only, were placed in 30 subjects aged 10 to 42 years wearing unimplanted 0.022 inch slot appliances. Nickel-titanium springs (150 g) were placed bilaterally to close the extraction spaces. Space closure was measured intraorally at monthly intervals until either the space on one side closed or 6 months had elapsed. The median rates of space closure were not significantly different between the ion-implanted and the unimplanted sides. The average rate of space closure on these beta-titanium wires, with or without ion implantation, was similar to the rate reported on stainless steel arch wires.

Adolescent↗

PubMed1998

Dental arch asymmetry in the mixed dentition.

Many orthodontists evaluate dental asymmetry clinically by comparing landmarks on the occlusal surfaces of dental casts. The purpose of this study was to quantify and describe maxillary and mandibular intra-arch asymmetry in 52 Caucasian children in the mixed dentition, and to determine if a relationship exists between intra-arch and interarch asymmetry. The median palatal plane (MPP) was used as a reference for transverse measurements. A computer-constructed transverse palatal plane (TPP) was the reference for anteroposterior measurements. Asymmetry greater than 2.0 mm was present at any one landmark in 25% of the sample. Transverse asymmetries exceeded anteroposterior asymmetries in magnitude and prevalence. The high association (Pearson's correlation) between the positions of anteroposterior and transverse interarch landmarks indicated that the arches had similar dimensions. Many children in the mixed dentition have intra-arch asymmetries that are more severe and prevalent in the transverse plane than in the anteroposterior plane.

Cephalometry↗

PubMed1998

Dental arch asymmetry in children with large overjets.

Little is known about asymmetry of children's dental arches. The purposes of this study were to quantify and describe dental arch asymmetry of 151 children with large overjets, and to determine if a spatial relationship exists between dental landmarks in opposing arches. The median palatal plane (MPP) was the reference for transverse measurements. A computer-constructed transverse palatal plane (TPP) was the reference for anteroposterior measurements. More than 30% of the children had transverse asymmetries > or = 2 mm at the maxillary first permanent molar (paired t-test; p = 0.0001). The highest mean transverse asymmetry (1.59 +/- 1.24 mm) and anteroposterior asymmetry (1.51 +/- 1.23 mm) were at the maxillary first permanent molars. A higher proportion of children with large overjets had clinically significant intra-arch asymmetries (> or = 2 mm) at several bilateral landmarks than norms (99% confidence intervals). Only 3% of these children exhibited interarch molar asymmetries > or = 4 mm. The position of the landmarks in one arch varied with the landmarks in the opposing arch (Pearson's correlation; p = 0.0001). Although many children with large overjets have significant intra-arch asymmetries, few exhibit asymmetric interarch asymmetries.

Cephalometry↗

PubMed1998

A common DLX3 gene mutation is responsible for tricho-dento-osseous syndrome in Virginia and North Carolina families.

Tricho-dento-osseous syndrome (TDO) is characterised by a variable clinical phenotype primarily affecting the hair, teeth, and bone. Different clinical features are observed between and within TDO families. It is not known whether the variable clinical features are the result of genetic heterogeneity or clinical variability. A gene for TDO was localised recently to chromosome 17q21 in four North Carolina families, and a 4 bp deletion in the human distal-less 3 gene (DLX3) was identified in all affected members. A previous genetic linkage study in a large Virginia kindred with TDO indicated possible linkage to the ABO, Gc, and Kell blood group loci. To examine whether TDO exhibits genetic heterogeneity, we have performed molecular genetic analysis to determine whether affected members of this Virginia kindred have the DLX3 gene deletion identified in North Carolina families. Results show that affected subjects (n=3) from the Virginia family have the same four nucleotide deletion previously identified in the North Carolina families. A common haplotype for three genetic markers surrounding the DLX3 gene was identified in all affected subjects in the North Carolina and Virginia families. These findings suggest that all people with TDO who have been evaluated have inherited the same DLX3 gene deletion mutation from a common ancestor. The variable clinical phenotype observed in these North Carolina and Virginia families, which share a common gene mutation, suggests that clinical variability is not the result of genetic heterogeneity at the major locus, but may reflect genetic heterogeneity at other epigenetic loci or contributing environmental factors or both.

Abnormalities, Multiple↗

PubMed1998

Enamel structure and composition in the tricho-dento-osseous syndrome.

Tricho-dento-osseous syndrome (TDO) is an autosomal dominant disorder characterized by curly hair, hypoplastic enamel, taurodontism, and dense bone. The purpose of this investigation was to characterize the enamel defects in a TDO population in North Carolina. Twelve TDO teeth and 12 normal teeth were examined. The enamel thickness was decreased in all TDO teeth ranging from having no enamel to about 60% the thickness of normal teeth. Half of the TDO teeth had primarily prismless enamel while the remainder had at least occasional areas of prismatic enamel. TDO enamel crystallites appeared similar to normal crystallites with TEM. The mineral per volume of TDO enamel (n = 9) (68.5%) was significantly less, on average, compared with normal enamel (n = 8) (84.5). The genetic mutation responsible for the TDO phenotype results in alteration of a developmental pathway(s) common to hair, teeth and bone. This further illustrates that these embryologically diverse tissues share common developmental controls at the molecular level.

Abnormalities, Multiple↗

PubMed1998

[Expression of fetal antigens of gonocytes in the investigation of pathogenesis of germinal cell neoplasia].

Expression of fetal antigens of germinal cells reacting with antibodies M2A and TRA-1-60 has been studied in fetal germinal cells-gonocytes (G) persisted in gonads of prepubertal boys because of male pseudohermaphroditism (MP) and in germinal carcinoma cells in situ (CIS) of adult men. The presence of G and CIS cells was detected immunohistochemically by identification of placental like alkaline phosphatase (PLAP). CIS cells showed expression of M2A in all adult men and additionally TRA-1-60 in one case. These antigens were present in G cells only in 2 out of 6 G bearing testes of boys with MP (30%). G cells were not found in testes of 3 other older boys with MP. So, in 1/3 cases of children with MP G cells show similar features like CIS cells during the prepubertal period indicating that they are able to enter malignant transformation in early prepubertal testis. Although total frequency of occurrence of G cells in MP boys was 2/3 (60%), their malignant transformation may be lower.

Antigens, Neoplasm↗

PubMed1997

Analysis of the tricho-dento-osseous syndrome genotype and phenotype.

The tricho-dento-osseous (TDO) syndrome demonstrates kinky curly hair, thin-pitted enamel, taurodontism, and thickening of cortical bone. The purpose of this investigation was to characterize the phenotypic variation of TDO in 3, previously unreported, kindreds and to examine possible candidates for the genomic TDO locus. Thirty-three affected and 20 unaffected individuals were recruited for prospective analysis. Participants were evaluated clinically and photographed by one examiner. Blood was drawn for genetic linkage analyses and radiographs were taken to assess dental and skeletal characteristics. All TDO individuals with teeth had generalized thin and/or pitted enamel hypoplasia. Taurodontism was present in all affected individuals, but was variably expressed. Unique kinky/curly hair at birth was reported in 85% of affected individuals. The curly hair phenotype was retained in 46% of affected individuals after infancy. Thick cranial bones, lack of visible pneumatization of the mastoid process, and/or obliteration of the calvarial diploë was seen in 97% of affected persons compared with 30% of the unaffected individuals. The findings suggest that curly hair at birth, enamel hypoplasia, and taurodontism are highly penetrant yet clinically variable components of TDO. The ABO, Kell, and Gc loci previously suggested to be linked to TDO were excluded as candidates in this TDO population. This investigation characterizes the marked variability in the expression of skeletal, hair, and dental manifestations. The broad range of TDO phenotypes seen in these families, including a variety of skeletal changes, does not support subdividing TDO into multiple subtypes based on subtle phenotypic differences.

Abnormalities, Multiple↗

PubMed1997

Effects of daily topical fluoride gels on resin composite degradation and wear.

OBJECTIVES: This in vitro study compares the effects of professional and consumer-applied topical fluorides on the weight, wear resistance and surface appearance of a resin composite containing barium boroaluminosilicate glass filler particles. METHODS: Prior to wear studies with a pin and disc apparatus, specimens were immersed for 6 min 10 times in water, three consumer-applied topical fluorides (1.1% NaF, 0.4% SnF2, or 0.5% APF gel) or a professionally applied topical fluoride (1.23% APF gel). Specimens were weighed before and after each immersion. Following wear studies, the specimen surfaces were visually evaluated using scanning electron microscopy. Weight changes were analyzed for significant differences using one-way ANOVA and Duncan's multiple range test (p = 0.01). Values of wear parameters were ranked and tested for significance using one-way ANOVA with least squares mean contrast (p = 0.05). RESULTS: Significant differences were found in the weight loss of specimens treated with different fluoride agents: 1.23% APF = 0.5% APF > 0.4% SnF2 > 1.1% NaF = water (p < or = 0.0001). Significant differences in initial wear depth (S(i)) occurred in the following samples: 1.23% APF > 1.1% NaF = 0.5% APF (p = 0.04). Scanning electron micrographs showed variable wear tracks on the specimen surfaces. The specimen surfaces outside the wear track were smooth for those treated with water or with NaF; the surfaces outside the wear track of specimens treated with APF showed extensive loss of filler particles. SIGNIFICANCE: Topical APF agents caused extensive loss of filler from the resin composite specimens whereas 1.1% NaF caused the least damage. Although significant differences in surface wear resistance were detected, clinical studies are needed to determine the effect of topical fluorides on the properties of this resin composite.

Acidulated Phosphate Fluoride↗

PubMed1997

Enlarged spectrum of seminological diagnoses using the resazurin colour reaction; a spectrophotometric application.

Two sets of investigations were carried out in the present study to establish whether, in semen samples processed for the resazurin reaction (RT), the colour change and its intensity were informative for both the quality and quantity of spermatozoa. First, the results of RT were read visually using single semen samples from 42 consecutive men from infertile couples. In the second step, the results were additionally read using a spectrophotometer. Single semen samples obtained from another 87 consecutive men from infertile couples and 12 men from fertile couples were analysed in this step. Visual analysis, which involved grading against and RT colour chart, revealed a significant positive correlation between the RT results and the quantity and quality of spermatozoa. Azoospermia was diagnosed by grade number 1 (dark purple colour), while the highest grades 8-11 (colours dark red to pink) represented a homogeneous group of patients with the highest quality of spermatozoa (> 60% motility) and quantity (> 60 x 10(6)/ml ejaculate). Normal parameters of spermatozoa, according to WHO, appeared with a high predominance (89-100% of cases) in this group and were present in most of the samples. Thus, the grades 8-11 might represent semen samples with optimal fertility potential. Spectrophotometric analysis of RT revealed that visual characteristics corresponded closely to the values for optical density (OD) of the samples. The OD for normozoospermic samples ranged between 1.48 and 1.84; for oligozoospermia between 1.2 and 1.48; for azoospermia between 0.98 and 1.1. The OD for samples with putative optimal fertility potential ranged between 1.6 and 1.84. RT evaluation using a spectrophotometer may therefore provide a tool for obtaining a wider spectrum of seminological diagnoses than classic microscopic examination, especially for distinguishing men with probable optimal fertility potential.

Adult↗

PubMed1997

Genetic linkage of the tricho-dento-osseous syndrome to chromosome 17q21.

Tricho-dento-osseous syndrome (TDO), MIM# 190320, is transmitted as a highly penetrant autosomal dominant trait that is characterized by variable clinical expression. The principal clinical features include kinky/curly hair in infancy, enamel hypoplasia, taurodontism, as well as increased thickness and density of cranial bones. Possible genetic linkage has been reported for TDO with the ABO blood group locus, but the gene defect remains unknown. We have identified four multiplex families (n = 63, 39 affected, 24 unaffected) from North Carolina segregating TDO. We previously have excluded a major locus for TDO in the ABO region for these families. Utilizing a genome-wide search strategy, we obtained conclusive evidence for linkage of the TDO syndrome locus to markers on chromosome 17q21 (D17S791, Z max = 10.54, Theta = 0.00) with no indication of genetic heterogeneity. Multipoint analysis suggests the TDO locus is located in a 7 cM chromosomal segment flanked by D17S932 and D17S941. This finding represents the first step towards isolation and cloning of the TDO gene. Identification of this gene has important implications for understanding normal and abnormal craniofacial development of hair, teeth and bone.

Abnormalities, Multiple↗

PubMed1996

Craniofacial morphology of the tricho-dento-osseous syndrome.

Tricho-dento-osseous syndrome (TDO) is characterized by abnormal bone, hair, and tooth morphology. However, the reported craniofacial abnormalities are not well characterized. The purpose of this study was to compare the craniofacial parameters of 25 subjects affected with TDO (A) with those of 15 unaffected relatives (U). Standardized lateral cephalograms were traced and digitized. Each subject's data were compared by age and sex to cephalometric standards (Bolton, Behrents); severity was scored by standard deviations from the standard mean, and then grouped into A vs. U. All cephalograms were evaluated for frontal sinuses, mastoid pneumatization, diploe, and bone density, and cranial thickness was measured. Cranial base length (SN; NBa), cranial base angle (BaSN), and mandibular body length (GoPg) were greater in A than in U (p < or = 0.05). Both groups had longer total and lower facial heights (NMe; ANSMe) compared with normal standards. Frontal sinuses, mastoid pneumatization and diploe were visible less often in A than in U (p < or = 0.05). Parietal bone and bone at lambda was significantly thicker (p < or = 0.05) in A than in U. Variability was substantial in many measures in both A and U. The major TDO craniofacial features involve the cranial base, mandibular body length, absence of visible pneumatized mastoids, frontal sinuses and diploe, and thicker cranial bone.

Abnormalities, Multiple↗

PubMed1996

[Precocious maturation of the testis associated with excessive secretion of estradiol and testosterone by Leydig cells].

We present the quantitative description of spermatogenesis in a 4.5-year-old boy with precocious puberty, where Leydig cell hyperplasia was associated with excessive secretion of testosterone (T), but predominantly with estradiol (E). The results were compared with data obtained from an age-matched group and adult men without hormonal abnormalities. We showed, that excessive secretion of T and E with relative deficiency of FSH is sufficient to induce testicular tubule maturation and qualitatively complete spermatogenesis, although with a poorer quantitative aspect.

Child, Preschool↗