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Biomedical subjects

J E Hunter

Publications and source records attributed to J E Hunter.

At least 19 recordsLinked to original sources
PubMed1995

The effect of cooling and hypertonic exposure on murine oocyte function, fertilization, and development.

Several individual but related steps are involved in the cryopreservation process, including the addition of cryoprotectants at various temperatures, cooling to subzero temperatures, and long-term storage. The process is completed by rewarming and removal of cryoprotectants prior to a return to physiological conditions. In this series of experiments we have attempted to distinguish the effects of some of these procedures. Control, untreated ovulated mouse oocytes showed 95% in vitro fertilization (190/200) and 92% subsequent development to hatching blastocyst (184/200). Exposure of oocytes to either isotonic or hypertonic media at 37 degrees C did not significantly change the rate of fertilization (90%, 108/120; and 89%, 154/174, respectively) or subsequent embryonic development (85%, 102/120; and 82%, 143/174, respectively). Slow cooling in isotonic medium (-3 degrees C/min) to 0 degree C had no effect on the rate of fertilization (83%, 103/124), but rapid cooling (> 1000 degrees C/min) to 0 degree C resulted in a significant reduction in fertilization rate to 75% (151/202). When oocytes suspended in a hypertonic solution were cooled using slow or rapid rates, there were marked decreases in fertilization to 26% (61/231) and 56% (156/278), respectively. Subsequent embryonic growth was reduced to 15% (34/231) after slow cooling and 26% (72/278) after rapid cooling. Exposure of oocytes to glycerol at 37 degrees C and dimethyl sulfoxide at 0 degree C reduced the fertilization rate to 57% (67/118) and 73% (103/145), respectively, with a corresponding reduction in embryonic growth to 52% (61/118) and 65% (94/145), but there were no additional effects of cooling or hypertonic exposure after addition of cryoprotectants.

Animals↗
PubMed1995

Vitrification of human oocytes following minimal exposure to cryoprotectants; initial studies on fertilization and embryonic development.

Investigations were made into the low temperature preservation of pre-ovulatory human oocytes by vitrification using a method of brief exposure of the oocytes to the vitrification solution at room temperature. Assessments of morphological survival, fertilization and embryonic development were recorded. All those oocytes exposed to the vitrification solution alone were morphologically normal and 86% of them were fertilized after incubation with spermatozoa. All the fertilized ova (86%) underwent cell division. Following cooling to -196 degrees C, morphological survival (65%) and fertilization (45%) rates remained high. However, in all vitrified oocytes, embryonic cell division and further development were inhibited. From our study it appears that fresh human oocytes can be vitrified using only brief exposure to cryoprotective agents and survive to undergo fertilization. However, progress remains to be made in achieving further embryonic development.

Cell Survival↗
PubMed1994

Therapeutic implications of lymph nodal spread in lateral T1 and T2 squamous cell carcinoma of the vulva.

From 1963 to 1993, 157 patients with primary squamous cell carcinoma of the vulva were treated by radical surgery at the University of Kentucky Medical Center. There were 84 unilateral lesions confined to the labium majus or labium minus. Thirty-seven patients had T1 lesions, median diameter 1.5 cm (range 0.5-2.0 cm), and 47 patients had T2 lesions, median diameter 3.4 cm (range 2.2-9.0 cm). Radical vulvectomy with bilateral inguinal lymphadenectomy was performed in 56 patients and radical hemivulvectomy with selective inguinal lymphadenectomy in 28 patients. An average of 8 nodes was removed with superficial inguinal lymphadenectomy and 13 nodes with superficial and deep inguinal lymphadenectomy. Deep inguinal lymph node metastases occurred only in patients with positive superficial inguinal lymph nodes. There were no contralateral inguinal lymph node metastases in any lateral T1 or T2 lesion. Following surgery, patients were followed 1-15 years (mean 5.0 years) and none have been lost to follow-up. Nine patients developed ipsilateral recurrences, but no contralateral recurrences were noted. Seven of these patients developed local recurrences to the ipsilateral vulvar skin and were cured by reexcision. Two patients (2.4%), both of whom had positive ipsilateral superficial and deep inguinal lymph node metastases at the time of initial surgery, developed distant metastases and died of disease 10 and 11 months after treatment. These data suggest that deep inguinal lymph nodal metastases occurred only in patients with superficial inguinal node involvement. Contralateral inguinal lymph nodal metastases are extremely rare in lateral T1 and T2 vulvar squamous cell carcinomas. Radical hemivulvectomy is as effective as radical vulvectomy in the treatment of lateral T1 and T2 vulvar squamous cell cancers.

Adult↗
PubMed1994

The prognostic and therapeutic implications of cytologic atypia in patients with endometrial hyperplasia.

From 1970 to 1992, 136 patients with a histologic diagnosis of endometrial hyperplasia underwent total abdominal hysterectomy at the University of Kentucky Medical Center. Slides of the curettage or biopsy specimens were reviewed and classified according to the International Society of Gynecologic Pathologists System as simple or complex endometrial hyperplasia with or without cytologic atypia. Slides of the hysterectomy specimens were likewise reviewed independently and classified according to the same system. Eighty-two patients had a preoperative diagnosis of simple or complex endometrial hyperplasia without atypia. There were no cases of occult endometrial carcinoma in the hysterectomy specimens of these patients. Simple or complex hyperplasia with atypia was present in 54 patients and endometrial adenocarcinoma was observed in 19 of these cases (35%). The International Federation of Gynecology and Obstetrics stage and histologic grade of these patients was as follows: Stage IA grade 1--5; Stage IB grade 1--10; Stage IB grade 2--1; Stage IC grade 1--1; Stage IC grade 2--1; and Stage IIIA grade 2--1. The risk of associated endometrial cancer in patients with atypical hyperplasia was independent of age, diabetes mellitus, hypertension, or the use of exogenous estrogens. All patients with endometrial cancer have been followed for 1-12 years (mean 3.0 years) after therapy and no patient has experienced tumor recurrence. These data suggest that there is a significant risk of endometrial cancer in patients with histologic evidence of atypical endometrial hyperplasia on curettage or biopsy. At the time of surgery, patients with atypical endometrial hyperplasia should have careful inspection of the uterine specimen. Any endometrial tissue suspicious for malignancy should be examined histologically, and if cancer is confirmed, complete surgical staging should be performed.

Adenocarcinoma↗
PubMed1994

The efficacy of a sonographic morphology index in identifying ovarian cancer: a multi-institutional investigation.

Transvaginal sonography (TVS) has been shown to be the most effective means to screen for ovarian cancer. TVS is associated with a high sensitivity and specificity. However, the positive predictive value associated with TVS in the diagnosis of malignancy is low. A morphologic scoring index for use with TVS has been used at the University of Kentucky since 1991. The current study was performed to more fully evaluate the efficacy and interobserver variation in ultrasonographic morphology index scores attributed to ovarian tumors. Ultrasound records of 213 patients from five participating centers were reviewed by three independent observers. Morphology index scores were assigned to each tumor in a blinded fashion. The morphology index scores were then compared with the final histopathologic findings. One hundred sixty-nine patients had benign tumors and 44 patients had ovarian malignancies. The mean morphology index scores were significantly higher in malignant ovarian tumors (MI 7.3 +/- 1.9) than in benign ovarian tumors (MI 3.3 +/- 1.8). Statistical evaluation of the morphology index scores revealed a sensitivity of 89% and a positive predictive value of 46%. Interobserver variation was lowest in assessing ovarian volume and higher in the evaluation of wall structure and septal structure. A multilogistic regression model was used to evaluate the predictive power of each component of the morphology index. The use of a morphology index is an effective and cost-efficient method of increasing the positive predictive value of TVS screening for ovarian cancer. Use of this index in large numbers of patients will generate data which should help refine appropriate structural scoring categories and reduce interobserver variation.

Adolescent↗
PubMed1994

Apramycin-resistant Escherichia coli isolated from pigs and a stockman.

Escherichia coli serotype O147:K89:K88a,c was found to be associated with outbreaks of diarrhoea in preweaner pigs of up to 4 weeks of age on a pig unit. Resistance to apramycin, gentamicin, netilmicin, tobramycin and other antibiotics was associated with conjugative plasmids of approximately 62 kb. The presence of a gene which encoded for the aminoglycoside acetyltransferase enzyme AAC(3)IV was confirmed by DNA hybridization. Samples collected during the following 12 months revealed widespread dissemination of these resistance plasmids in non-serotypable, non-haemolytic E. coli throughout the farm. Apramycin-resistant E. coli were also isolated from a stockman and it appeared from plasmid profile analysis and antibiotic sensitivity testing that the human isolates carried the same plasmid as that carried by the porcine E. coli. Klebsiella pneumoniae, with a slightly smaller conjugative plasmid and similar resistance pattern, was isolated from the stockman's wife.

Agricultural Workers' Diseases↗
PubMed1994

Recognition and medical management of necrotizing enterocolitis.

The signs and symptoms associated with necrotizing enterocolitis (NEC) and the common scenarios in which NEC is observed are described to help physicians appreciate the breadth of this illness and to aid in the identification and diagnosis of those affected. An outline for medical management of infants with NEC is presented, based on the pathophysiology of this disease.

Enterocolitis, Pseudomembranous↗
PubMed1993

A morphology index based on sonographic findings in ovarian cancer.

A morphology index based on morphologic characteristics of ovarian tumors was developed. Specific categories included tumor volume, wall structure, and septal structure. A point scale (0-4) was developed within each category with the total points per evaluation varying from 0-12. Sonograms on 121 patients undergoing exploratory laparotomy for ovarian masses were evaluated using this index. Eighty ovarian tumors had a morphology index score < 5, and all were benign (negative predictive value, 1.000). In postmenopausal patients, a morphology index score > or = 5 had a positive predictive value for malignancy of 0.45. All ovarian malignancies had significant abnormalities in wall structure and all had a total volume in excess of 10 cm3. The findings of the present investigation indicate that the morphology index is a cost effective adjuvant method which significantly increases the specificity and positive predictive value of transvaginal sonography. The routine application of a morphology index to screening sonography should decrease the amount of diagnostic surgery performed in order to detect each case of ovarian cancer.

Adolescent↗
PubMed1993

Ovarian cancer screening in asymptomatic postmenopausal women.

From 1987 to 1992, 3220 asymptomatic postmenopausal women underwent screening with transvaginal sonography (TVS) as part of the University of Kentucky Ovarian Cancer Screening Project. Ovarian volume was calculated using the prolate ellipsoid formula (length x height x width x 0.523). An abnormal sonogram was defined by (1) an ovarian volume > 10cm3 or (2) a papillary projection into a cystic ovarian tumor. All women with an abnormal TVS had a repeat sonogram in 4-6 weeks. If the repeat sonogram was abnormal, a morphology index score was assigned to each tumor, and a serum CA-125 was obtained. The patient then had a pelvic examination and an exploratory laparotomy. Forty-four patients (1.4%) with a persisting abnormality on TVS underwent exploratory laparotomy. Twenty-one patients had serous cystadenomas and 3 had primary ovarian cancers. Two patients with primary ovarian cancer had Stage IA disease and one had Stage IIIB disease. All patients with ovarian cancer had normal pelvic examinations and normal serum CA-125 levels, and are presently alive and well 32, 31, and 8 months after conventional therapy. Over 5000 screening years have been accumulated at this institution, and there have been no ovarian cancer deaths in the screened population. TVS screening has produced a decrease in stage at detection and case-specific mortality from ovarian cancer. A multi-institutional trial to test the efficacy of TVS as a screening method for ovarian cancer is indicated.

Adult↗
PubMed1993

Plasmid encoded beta-lactamases resistant to inhibition by clavulanic acid produced by calf faecal coliforms.

Two new plasmid encoded beta-lactamase enzymes produced by a strain of Escherichia coli and a strain of Citrobacter freundii isolated from calf faeces have been characterised. Both enzymes were similar to TEM-1 in terms of substrate and inhibition profiles and physical properties but differed from TEM-1 in being far less susceptible to the beta-lactamase inhibitors clavulanic acid or tazobactam. In each case transfer of the plasmid E coli K12 rendered it clinically resistant to the combination of amoxycillin and clavulanic acid. The beta-lactamase from the E coli had an iso-electric point (pI) of 5.4 and was encoded on a plasmid of 95 Kbp which also mediated resistance to tetracycline, sulphonamides, apramycin, streptomycin and gentamicin. The beta-lactamase from the C freundii had a pI of 5.2 and was encoded on a 75 Kbp plasmid which also mediated resistance to trimethoprim, chloramphenicol, apramycin, gentamicin and tobramycin.

Amoxicillin↗
PubMed1993

DNA sequence variation and phylogenetic relationships among strains of Pseudomonas syringae pv. syringae inferred from restriction site maps and restriction fragment length polymorphism.

We evaluated the restriction fragment length polymorphism of genomic DNA among 53 strains of the phytopathogenic bacterium Pseudomonas syringae pv. syringae. Twenty-nine strains were isolated from beans, and the rest were isolated from 11 other hosts. Southern blots of DNA digested with EcoRI or HindIII were hybridized to two random probes from a cosmid library of P. syringae pv. syringae and a hrp (hypersensitive reaction and pathogenicity) cluster cloned from P. syringae pv. syringae. The size of hybridizing fragments was determined, and a similarity matrix was constructed by comparing strains on a pairwise basis for the presence or absence of fragments. The proportion of shared fragments was then used to estimate sequence divergence. Dendrograms were produced by using the unweighted pair group method with averages and the neighbor-joining method. For the hrp region, BamHI, EcoRI, EcoRV, and HindIII restriction sites were mapped for six representative bean strains and used to construct EcoRI and HindIII restriction maps for all 30 strains pathogenic on beans. Restriction mapping revealed the presence of a 3-kb insertion in nine bean strains and a probable second insertion or deletion event on the left-hand side of the hrp cluster that biased estimates of nucleotide sequence divergence from fragment comparisons. This demonstrated that the determination of phylogenetic relationships among bacteria by using restriction fragment length polymorphism data requires mapping restriction sites to remove the effect of insertion or deletion events on the analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA, Bacterial↗
PubMed1992

Measurements of the membrane water permeability (Lp) and its temperature dependence (activation energy) in human fresh and failed-to-fertilize oocytes and mouse oocyte.

The volumetric response of oocytes during rapid alterations of the extracellular osmotic environment were recorded using video microscopy. From these observations, the kinetics of water loss for human and mouse oocytes were determined over the temperature range 37 to 10 degrees C, including 37, 30, 20, and 10 degrees C. The changes in diameter of oocytes were measured over a 5-min period and a computer model was used to derive values for membrane water permeability (Lp) and inactive volume (Vb) and to compare the experimental data to the predicted values. The results for the mouse oocyte Lp were comparable to values determined by other methods. However the human data, for both failed-to-fertilize and fresh oocytes, have a wide range of values with large standard deviations. The Lp values at the various temperatures were used to calculate the Arrhenius activation energy (Ea). An Ea value of 9.48 kcal/mol was found for the fresh mouse oocyte, whereas the activation energy for human oocytes was extremely low, 3.73 kcal/mol for fresh oocytes and 1.93 kcal/mol for failed-to-fertilize oocytes.

Animals↗
PubMed1992

Transition from benign to malignant epithelium in mucinous and serous ovarian cystadenocarcinoma.

The slides of all patients with ovarian cystadenocarcinoma treated at the University of Kentucky Medical Center from 1966-1990 were reviewed. Fifty-four serous tumors and 42 mucinous neoplasms were identified for further study. Benign epithelium adjacent to an area of borderline or malignant epithelium was observed in 74 tumors (79%) and a site of epithelial transition was noted in 38 cases (40%). The presence of associated benign epithelium was more common in borderline or well-differentiated lesions and in patients with early-stage disease. These findings are consistent with epidemiologic and molecular genetic data and suggest that certain benign serous or mucinous ovarian tumors have the potential for malignant transformation. Removal of these tumors, particularly in postmenopausal women, should result in a subsequent reduction in the frequency of ovarian cancer.

Adolescent↗